PFC exposure tied to altered thyroid function

Contact: Jenni Glenn Gingery
jgingery@endocrine.org
301-941-0240
The Endocrine Society

Endocrine-disrupting chemicals may increase odds of women developing mild hypothyroidism

Chevy Chase, MD—Exposure to perfluorinated chemicals is linked to changes in thyroid function and may raise the risk of mild hypothyroidism in women, according to a recent study accepted for publication in The Endocrine Society’s Journal of Clinical Endocrinology & Metabolism (JCEM).

Perfluorinated chemicals, or PFCs, are compounds used to manufacture fabrics, carpets, paper coatings, cosmetics and a variety of other products. Among humans and wildlife, PFC exposure is widespread, according to the National Institutes of Health’s National Institute of Environmental Health Sciences. Because these chemicals break down very slowly, it takes a long time for PFCs to leave the body.

“Our study is the first to link PFC levels in the blood with changes in thyroid function using a nationally representative survey of American adults,” said one of the study’s authors, Chien-Yu Lin, MD, PhD, of En Chu Kong Hospital in Taiwan.

Women who had higher levels of a PFC called perfluorooctanoate (PFOA) in their blood tended to have elevated levels of the thyroid hormone triiodothyronine (T3). The study also found an increase in levels of T3 and the thyroid hormone thyroxine (T4) in women with higher concentrations of the PFC perfluorohexane sulfonate (PFHxS) in their blood. The levels rose without the pituitary gland signaling the thyroid to produce more hormones, which is the body’s natural mechanism for adjusting thyroid hormone levels. Men exposed to higher amounts of PFHxS, however, tended to have lower levels of the T4 hormone.

Even though people with a history of thyroid diseases were excluded from the study, researchers found an association between subclinical, or mild, hypothyroidism and elevated levels of PFOA, PFHxS and perfluorooctane sulfonate (PFOS) in women. Hypothyroidism occurs when the thyroid gland does not produce enough hormones and can cause symptoms such as fatigue, mental depression, weight gain, feeling cold, dry skin and hair, constipation and menstrual irregularities. This relationship needs to be explored and confirmed through additional research, Lin said.

The researchers analyzed data from 1,181 participants in the 2007-2008 and 2009-2010 National Health and Nutrition Examination Survey (NHANES), a population-based survey conducted by the Centers for Disease Control and Prevention (CDC). The study reviewed levels of four different PFCs as well as thyroid function.

“Although some PFCs such as PFOS have been phased out of production by major manufacturers, these endocrine-disrupting chemicals remain a concern because they linger in the body for extended periods,” Lin said. “Too little information is available about the possible long-term effects these chemicals could have on human health.”

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Other researchers working on the study include: L. Wen of En Chu Kong Hospital, L. Lin and T. Su of National Taiwan University Hospital and P. Chen of National Taiwan University College of Public Health.

The article, “Association between Serum Perfluorinated Chemicals and Thyroid Function in U.S. Adults: the National Health and Nutrition Examination Survey 2007-2010,” was published online July 17.

Founded in 1916, The Endocrine Society is the world’s oldest, largest and most active organization devoted to research on hormones and the clinical practice of endocrinology. Today, The Endocrine Society’s membership consists of over 16,000 scientists, physicians, educators, nurses and students in more than 100 countries. Society members represent all basic, applied and clinical interests in endocrinology. The Endocrine Society is based in Chevy Chase, Maryland. To learn more about the Society and the field of endocrinology, visit our site at http://www.endocrine.org. Follow us on Twitter at https://twitter.com/#!/EndoMedia.

UT study: Chemical in antibacterial soaps may harm nursing babies

Contact: Lola Alapo lalapo@utk.edu 865-974-3993 University of Tennessee at Knoxville

KNOXVILLE—A mother’s prolonged use of antibacterial soaps containing the chemical triclocarban may harm nursing babies, according to a recent study from the University of Tennessee, Knoxville.

The study, which was conducted on rats, showed that exposure to the compound may reduce the survival rates of babies.

Rebekah Kennedy, a UT graduate student pursuing a dual master’s degree in public health and nutrition, and Jiangang Chen, an assistant professor in the UT Department of Public Health, presented the results this month at the Endocrine Society’s 95th Annual Meeting and Expo in San Francisco. Kennedy was the study’s lead author.

Triclocarban, a bactericide, is found primarily in antibacterial bar soaps.

The researchers noted that they were not condemning the use of antibacterial soaps.

“People have to weigh their own risks and decide what would be the best route,” Kennedy said. “There’s always a time and place for antibacterial bar soaps, such as in health care settings where the chance of infection and transmission is high. For the average person, antibacterial soap is no more effective than regular soap.”

Chen conducted an earlier study that examined how prolonged exposure to triclocarban affected growth of sex organs in adult male rats. Kennedy decided to go a step further and look into how it would affect baby rats in the womb and during nursing.

Humans are exposed to triclocarban through skin absorption. Research shows that based on how the compound is biotransformed, oral exposure in rats is similar to dermal exposure for humans, Kennedy said.

During Kennedy’s research, pregnant rats fed with triclocarban through food had similar blood concentrations compared to human blood concentrations after a 15-minute shower using antibacterial soap.

The study found that triclocarban did not affect the post-birth survival rate of baby rats exposed to the compound in the womb. But baby rats nursed by mothers that were exposed to the compound did not survive beyond the sixth day after birth.

The results showed that a mother’s long-term use and exposure to triclocarban could affect her baby’s early development, according to the animal model, Kennedy said.

Humans may be exposed to triclocarban through other ways besides skin absorption, including produce consumption, Chen said. Triclocarban is washed down the drain, where about 95 percent of it is removed when wastewater is treated. The remainder may still be a problem, particularly since treated wastewater is used for agricultural purposes.

“There are potential exposure routes in daily life we are not aware of,” Chen said. “The goal is to try to minimize those if at all possible.”

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The research was supported by the National Institutes of Health’s National Institute of Environmental Health Sciences.

To learn more about the study, visit http://tinyurl.com/nhvyd47.

CONTACTS:

Lola Alapo (865-974-3993, lalapo@utk.edu)

Jiangang Chen (865-974-8487, jchen38@utk.edu)

Rebekah Kennedy (865-974-8487, rkenne12@utk.edu)

Chemical in antibacterial soap fed to nursing rats harms offspring

Contact: Jenni Glenn Gingery
jgingery@endocrine.org
301-941-0240
The Endocrine Society

 

SAN FRANCISCO—- A mother’s exposure to triclocarban, a common antibacterial chemical, while nursing her babies shortens the life of her female offspring, a new study in rats finds. The results were presented Monday at The Endocrine Society’s 95th Annual Meeting in San Francisco.

Commonly used in antibacterial soap and other personal care products, triclocarban has the potential for a large portion of the public to be exposed to it, said the study’s lead author, Rebekah Kennedy, a graduate student in the Department of Public Health at the University of Tennessee, Knoxville.

“Our study provides supporting evidence for the potential adverse effects of triclocarban exposure during early life, specifically during the lactation period,” Kennedy said. “The results indicate that a mother’s long-term use of this compound might affect the early development of her offspring, at least according to our animal model.”

Past studies by the senior investigator, Jiangang Chen, PhD, an assistant professor at the University of Tennessee, showed that triclocarban enhances the growth of sex organs in the adult male rat. In this study, the researchers sought to learn if exposure to the same compound, either in the womb or during lactation, would affect rat pups.

Beginning on pregnancy day 5 and continuing until 21 days after giving birth, maternal rats continuously had free access to regular rat chow (the control rats) or chow supplemented with either 0.2 or 0.5 percent triclocarban. The doses found in the blood of maternal rats exposed to triclocarban correspond to blood levels of triclocarban in humans after a 15-minute whole-body shower using a bar soap containing 0.6 percent triclocarban, Chen said.

After birth, some littermates were moved to other groups so that each rat mother nursed two of her own pups and two pups from each of the other two groups. The offspring were weighed daily.

Body weight did not differ at birth among rat pups from the three groups, but by day 3, pups nursed by control rats were heavier than either triclocarban-exposed group, Kennedy reported. Pups nursed by rats that received 0.2 percent triclocarban were about half as heavy at weaning on day 21 as pups nursed by controls, and only 4 of 30 pups survived.

The investigators found that all pups nursed by the control rats survived until weaning, including those born to triclocarban-fed maternal rats but nursed by control rats. No pups nursed by rats that received the larger triclocarban dose, 0.5 percent, survived until day 6. Among pups nursed by rats that received the 0.2 percent dose of triclocarban, 57 percent reportedly lived to nine days after birth, and only 13% survived after weaning.

“Our data suggest that the critical exposure window affecting rat pup survival is related to lactation, as all pups raised by control rats survived regardless of triclocarban exposure status during gestation,” Kennedy said.

Although the researchers did not measure triclocarban levels in the offspring, they speculate that the chemical entered the gastrointestinal tract through the mother’s milk and affected the pups’ growth and development.

The National Institutes of Health’s National Institute of Environmental Health Sciences supported this research.

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Founded in 1916, The Endocrine Society is the world’s oldest, largest and most active organization devoted to research on hormones and the clinical practice of endocrinology. Today, The Endocrine Society’s membership consists of over 16,000 scientists, physicians, educators, nurses and students in more than 100 countries. Society members represent all basic, applied and clinical interests in endocrinology. The Endocrine Society is based in Chevy Chase, Maryland. To learn more about the Society and the field of endocrinology, visit our site at http://www.endocrine.org. Follow us on Twitter.

Prenatal exposure to BPA affects fat tissues in sheep

Contact: Jenni Glenn Gingery
jgingery@endocrine.org
301-941-0240
The Endocrine Society

 

SAN FRANCISCO-— New research suggests that fetal exposure to the common environmental chemical bisphenol A, or BPA, causes increased inflammation in fat tissues after birth, which can lead to obesity and metabolic syndrome. Results of the animal study were presented Monday at The Endocrine Society’s 95th Annual Meeting in San Francisco.

Found in plastic water bottles, older baby bottles and many other consumer products, BPA is a known hormone disrupter with estrogen-like properties. Prior research has linked BPA in both animals and humans to obesity and the metabolic syndrome, which is a cluster of metabolic risk factors that increase the chance of later developing diabetes, heart disease and stroke.

“This research is the first study to show that prenatal exposure to BPA increases postnatal fat tissue inflammation, a condition that underlies the onset of metabolic diseases such as obesity, diabetes and cardiovascular disease,” said the study’s lead author, Almudena Veiga-Lopez, DVM, PhD, a research investigator at the University of Michigan, Ann Arbor.

She said the study, which examines the effects of BPA on sheep, improves the understanding of how prenatal BPA exposure regulates the inflammatory response in offspring in the tissues that are relevant to development of metabolic disease. The study was conducted in the laboratory of Vasantha Padmanabhan, MS, PhD, Professor at the University of Michigan, Ann Arbor, with funding from the National Institutes of Health’s National Institutes of Environmental Health Sciences. Veiga-Lopez said sheep have similar body fat to that in humans, including visceral (deep belly) fat and subcutaneous fat, which is directly below the skin.

The researchers fed two groups of pregnant sheep corn oil, either with nothing added to it or with added BPA at a dose needed to achieve BPA levels similar to those seen in human cord blood in the umbilical cord blood of the sheep offspring. Of the female offspring from the sheep, half from each group were overfed at approximately 6 weeks of age. All female offspring then were divided into four groups of nine to 12 animals each: (1) non-BPA-exposed controls that received a normal diet, (2) BPA-exposed offspring that received a normal diet, (3) overfed, obese controls and (4) overfed, obese BPA-exposed offspring.

At 15 months of age, sheep underwent a glucose tolerance test, to measure their insulin and blood sugar levels. Seven months later, the researchers collected samples of the animals’ visceral and subcutaneous fat tissues to evaluate levels of two biological markers of inflammation. These biomarkers were CD68, a marker for inflammatory cells, and adiponectin, a molecule with a known role in the development of metabolic syndrome. When the adiponectin level decreases or CD68 expression increases, inflammation is worse, according to Veiga-Lopez.

Adiponectin was decreased and CD68 expression was raised in the visceral fat of both obese groups, and CD68 expression also was raised in the subcutaneous fat in normal weight, BPA-exposed female offspring, Veiga-Lopez reported. She said these results suggest that “prenatal BPA exposure and postnatal diet may interact to modulate inflammatory mechanisms in fat deposits.”

Both obese groups had hyperinsulinemia, or high insulin levels, a precursor to insulin resistance, which is a prediabetic state, Veiga-Lopez reported. However, she said prenatal exposure to BPA did not lead to insulin resistance in sheep, as was true in a previous mouse study. She speculated that the hyperinsulinemia in obese offspring stems from changes that occurred in the two inflammatory markers in the visceral fat deposit.

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Founded in 1916, The Endocrine Society is the world’s oldest, largest and most active organization devoted to research on hormones and the clinical practice of endocrinology. Today, The Endocrine Society’s membership consists of over 16,000 scientists, physicians, educators, nurses and students in more than 100 countries. Society members represent all basic, applied and clinical interests in endocrinology. The Endocrine Society is based in Chevy Chase, Maryland. To learn more about the Society and the field of endocrinology, visit our site at http://www.endocrine.org. Follow us on Twitter.

BPA linked to a common birth defect in boys

Contact: Jenni Glenn Gingery jgingery@endocrine.org 301-941-0240 The Endocrine Society

SAN FRANCISCO– A new study links fetal exposure to a common chemical pollutant, bisphenol A (BPA), to defects of a testicular hormone in newborn boys with undescended testicles. The results, which were presented Monday at The Endocrine Society’s 95th Annual Meeting in San Francisco, suggest yet another potential harmful effect of BPA, which is widely used in many plastics, liners of food cans and dental sealants.

“Alone, our study cannot be considered as definitive evidence for an environmental cause of undescended testis,” said lead author Patrick Fenichel, MD, PhD, professor and head of reproductive endocrinology at the University Hospital of Nice in France. “But it suggests, for the first time in humans, a link that could contribute to one co-factor of idiopathic [unexplained] undescended testis, the most frequent congenital malformation in male newborns.”

Cryptorchidism, the medical name for undescended testicles, occurs in 2 to 5 percent of full-term male newborns, according to Fenichel. Sometimes the testicles descend on their own within six months after birth. If the condition persists and goes untreated, however, it carries an increased risk in adulthood of decreased fertility and testicular cancer, he said.

Fenichel and his colleagues studied 180 boys born after 34 weeks’ gestation between 2003 and 2005. Fifty-two were born with one or two undescended testicles, 26 of whom still had the condition at 3 months of age. The other 128 newborns did not have this birth defect and were matched for pregnancy term, weight and time of birth (the control group). Using sensitive immunoassays of the infants’ umbilical cord blood, the researchers measured the newborns’ levels of BPA and insulin-like peptide 3, one of the two testicular hormones that regulate descent of the testicles.

Testosterone level, which also controls fetal testicular descent, did not differ between the groups and was normal in the whole population, according to Fenichel.

The infants with cryptorchidism had significantly lower levels of insulin-like peptide 3, compared with the controls, the authors reported. These infants did not have greatly increased levels of BPA or several other environmental endocrine disrupters that were measured. However, in all 180 infants, the BPA level inversely correlated with the level of insulin-like peptide 3, meaning that the higher the BPA level, the lower the level of this important testicular hormone.

Fenichel speculated that BPA, an estrogenic endocrine disruptor, might repress, as other research has shown for estrogens in rodents, expression of the gene for insulin-like peptide 3. This could be a co-factor in the development of cryptorchidism, he said.

Animal research also has linked fetal BPA exposure to an increased risk of reproductive disorders and other health problems.

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Founded in 1916, The Endocrine Society is the world’s oldest, largest and most active organization devoted to research on hormones and the clinical practice of endocrinology.  Today, The Endocrine Society’s membership consists of over 16,000 scientists, physicians, educators, nurses and students in more than 100 countries. Society members represent all basic, applied and clinical interests in endocrinology. The Endocrine Society is based in Chevy Chase, Maryland. To learn more about the Society and the field of endocrinology, visit our site at http://www.endocrine.org. Follow us on Twitter.

Vitamin D supplementation may delay precocious puberty in girls

Contact: Jenni Glenn Gingery jgingery@endocrine.org 301-941-0240 The Endocrine Society

SAN FRANCISCO– Vitamin D supplementation may help delay early onset of puberty in girls, a new clinical study finds. The results were presented Monday at The Endocrine Society’s 95th Annual Meeting in San Francisco.

Among girls, puberty generally begins between the ages of 10 and 14. Boys undergo these changes later, usually between 12 to 16 years of age. Precocious puberty is diagnosed in girls when sexual development begins before the age of 8; in boys, it is diagnosed when these changes occur before age 9.

Recently, medical research has linked vitamin D deficiency to a number of diseases, including cancer, obesity and autoimmune disease. Low vitamin D levels have been found in girls with precocious puberty, as well, although the exact relationship between vitamin D deficiency and early development remains unclear.

To determine how low vitamin D deficiency is related to precocious puberty, investigators in the current study compared blood levels of the vitamin between girls with early and normal development.

They found that girls with precocious puberty were significantly more likely than those with age-appropriate development to have a severe vitamin D deficiency. Among the precocious puberty group, 44 percent had a severe deficiency in vitamin D, compared to 21 percent of the group with age-appropriate physical development.

Additionally, investigators examined the activity of neurons responsible for stimulating the release of a hormone that triggers the ovulation process.  Specifically, investigators used the neuron-stimulating compound called N-methyl-D-aspartate, or NMDA, to activate the neurons responsible for releasing gondadotropin-releasing hormone, or GnRH. They found that vitamin D was associated with a suppression of the NMDA-mediated neuronal activities on GnRH neurons.

“If we understand more about the action mechanism of vitamin D on GnRH neuronal activities, we can find a clue to control of precocious puberty using vitamin D or related molecules,” said study lead author Min Sun Kim, MD, PhD, assistant professor at Chonbuk National University Medical School in Jeonju, South Korea. “Our results suggest that vitamin D may inhibit early pubertal onset and/or the rapid progression of puberty, at least in part, through the suppression of NMDA-mediated GnRH neuronal excitation in humans.”

Study participants included 110 girls between the ages of 7 to 10 years. Seventy-five girls exhibited normal patterns of development, while 35 were classified as having precocious puberty. Investigators used the Tanner scale, which assesses human physical development, to differentiate normal versus precocious pubertal development.

According to Kim, more research, including studies in animal models, is necessary to confirm this project’s findings.

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Founded in 1916, The Endocrine Society is the world’s oldest, largest and most active organization devoted to research on hormones and the clinical practice of endocrinology.  Today, The Endocrine Society’s membership consists of over 16,000 scientists, physicians, educators, nurses and students in more than 100 countries. Society members represent all basic, applied and clinical interests in endocrinology. The Endocrine Society is based in Chevy Chase, Maryland. To learn more about the Society and the field of endocrinology, visit our site at http://www.endocrine.org. Follow us on Twitter.

Short-term antidepressant use, stress, high-fat diet linked to long-term weight gain

Contact: Jenni Glenn Gingery jgingery@endocrine.org 301-941-0240 The Endocrine Society

SAN FRANCISCO—- Short-term use of antidepressants, combined with stress and a high-fat diet, is associated with long-term increases in body weight, a new animal study finds. The results were presented Sunday at The Endocrine Society’s 95th Annual Meeting in San Francisco.

“Our study suggests that short-term exposure to stress and antidepressants, rather than a high-calorie, high-fat diet alone, leads to long-term body weight gain, accompanied with increased bone and spleen weights,” said study lead author Suhyun Lee, a PhD candidate in the medical sciences at the John Curtin School of Medical Research at the Australian National University in Canberra, Australia.

Antidepressants are among the most prevalent medications today, accounting for millions of prescriptions each year. In the United States, physicians wrote more than 1.5 million prescriptions for antidepressants in 2009, while physicians in Australia wrote more than 12 million of these prescriptions in 2008.

At the same time, obesity rates are climbing in developed countries worldwide. Among adults in both the United States and Australia, two-thirds are overweight or obese. Being overweight or obese is a risk factor for many serious diseases, including heart disease, which is the leading cause of death among adults in the United States and Australia.

Unfortunately, weight gain is one of the main side effects associated with antidepressants. The amount of excess weight varies between patients, but some have reported increases as high as 7 percent of the amount they weighed at the start of their antidepressant treatment.

In this study, male rats treated with the antidepressant fluoxetine after induced stress had significantly increased body weight compared to control animals. In addition to greater overall body weight, animals in the antidepressant group also developed greater bone and spleen weights, compared to animals in the control group.

“These findings may implicate different pathophysiological mechanisms in stress and antidepressant related obesity when compared to obesity that is solely diet-induced,” Lee said.

During the follow-up, investigators also compared behavior between the drug and control groups. This comparison showed that the antidepressants reduced anxiety among the animals in response to induced stress. After the stressful periods, which involved physical restraint, the fluoxetine-treated animals exhibited significantly fewer symptoms of anxiety, compared to the control animals.

The study involved a two-week period of repeated restraint stress, combined with antidepressant treatment among one group of animals, and saline administration among the control group. After the two-week period, both groups of animals received a high-fat diet for 295 days.

The John Curtin School of Medical Research, Australian National University funded the study.

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Founded in 1916, The Endocrine Society is the world’s oldest, largest and most active organization devoted to research on hormones and the clinical practice of endocrinology.  Today, The Endocrine Society’s membership consists of over 16,000 scientists, physicians, educators, nurses and students in more than 100 countries. Society members represent all basic, applied and clinical interests in endocrinology. The Endocrine Society is based in Chevy Chase, Maryland. To learn more about the Society and the field of endocrinology, visit our site at http://www.endocrine.org. Follow us on Twitter.

Calcium supplements linked to longer lifespans in women

Contact: Jenni Glenn Gingery jgingery@endo-society.org 301-941-0240 The Endocrine Society

Study finds calcium-rich diet, supplements provide equal benefits

Chevy Chase, MD—Taking a calcium supplement of up to 1,000 mg per day can help women live longer, according to a recent study accepted for publication in The Endocrine Society’s Journal of Clinical Endocrinology & Metabolism (JCEM).

Calcium, an essential nutrient for bone health, is commonly found in dairy products as well as vitamins. Although calcium is an essential nutrient for bone health, past studies have linked calcium supplements to heart disease risk. Researchers analyzing data from the large-scale Canadian Multicentre Osteoporosis Study (CaMos) sought to clarify this issue and found moderate doses of calcium supplements had a beneficial effect in women.

“Our study found daily use of calcium supplements was associated with a lower risk of death among women,” said the study’s lead author, David Goltzman, MD, of McGill University in Montreal, Canada. “The benefit was seen for women who took doses of up to 1,000 mg per day, regardless of whether the supplement contained vitamin D.”

The longitudinal cohort study monitored the health of 9,033 Canadians between 1995 and 2007. During that period, 1,160 participants died. Although the data showed women who took calcium supplements had a lower mortality risk, there was no statistical benefit for men. The study found no conclusive evidence that vitamin D had an impact on mortality.

“Higher amounts of calcium were potentially linked to longer lifespans in women, regardless of the source of the calcium,” Goltzman said. “That is, the same benefits were seen when the calcium came from dairy foods, non-dairy foods or supplements.”

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Other researchers working on the study include: L. Langsetmo, C. Berger, J. Genest and S. Morin of McGill University; N. Krieger, S. Jamal and R. Josse of the University of Toronto; C. Kovacs of Memorial University in St. John’s, Newfoundland; D. Hanley of the University of Calgary; S. Whiting of the University of Saskatchewan; A. Hodsman of St. Joseph’s Health Center in London, Ontario; J. Prior, B. Lentle and M. Patel of the University of British Columbia; J. Brown of Laval University in Quebec; T. Anastasiades and T. Towheed, of Queen’s University in Kingston, Ontario; A. Papaioannou, J. Adachi of McMaster University in Hamilton, Ontario; W. Leslie of the University of Manitoba; and K. Davison of the University of Victoria in British Columbia.

The article, “Calcium and Vitamin D Intake and Mortality: Results from the Canadian Multi-centre Osteoporosis Study,” will appear in the July 2013 issue of JCEM.

Founded in 1916, The Endocrine Society is the world’s oldest, largest and most active organization devoted to research on hormones and the clinical practice of endocrinology.  Today, The Endocrine Society’s membership consists of over 16,000 scientists, physicians, educators, nurses and students in more than 100 countries. Society members represent all basic, applied and clinical interests in endocrinology. The Endocrine Society is based in Chevy Chase, Maryland. To learn more about the Society and the field of endocrinology, visit our site at http://www.endo-society.org. Follow us on Twitter at https://twitter.com/#!/EndoMedia.

Mild iodine deficiency in womb associated with lower scores on children’s literacy tests

Contact: Jenni Glenn Gingery jgingery@endo-society.org 301-941-0240 The Endocrine Society

Changes in mother’s diet, supplements may prevent long-term neurological impairment

Chevy Chase, MD––Children who did not receive enough iodine in the womb performed worse on literacy tests as 9-year-olds than their peers, according to a recent study accepted for publication in The Endocrine Society’s Journal of Clinical Endocrinology & Metabolism (JCEM).

Iodine is absorbed from food and plays a key role in brain development. Even mild deficiency during pregnancy can harm the baby’s neurological development.

“Our research found children may continue to experience the effects of insufficient iodine for years after birth,” said the study’s lead author, Kristen L. Hynes, PhD, of the Menzies Research Institute at the University of Tasmania in Australia. “Although the participants’ diet was fortified with iodine during childhood, later supplementation was not enough to reverse the impact of the deficiency during the mother’s pregnancy.”

The longitudinal study examined standardized test scores of 228 children whose mothers attended The Royal Hobart Hospital’s antenatal clinics in Tasmania between 1999 and 2001. The children were born during a period of mild iodine deficiency in the population. Conditions were reversed when bread manufacturers began using iodized salt in October 2001 as part of a voluntary iodine fortification program.

The study found inadequate iodine exposure during pregnancy was associated with lasting effects. As 9-year-olds, the children who received insufficient iodine in the womb had lower scores on standardized literacy tests, particularly in spelling. However, inadequate iodine exposure was not associated with lower scores on math tests. Researchers theorize iodine deficiency may take more of a toll on the development of auditory pathways and, consequently, auditory working memory and so had more of an impact on students’ spelling ability than their mathematical reasoning ability.

“Fortunately, iodine deficiency during pregnancy and the resulting neurological impact is preventable,” Hynes said. “Pregnant women should follow public health guidelines and take daily dietary supplements containing iodine. Public health supplementation programs also can play a key role in monitoring how much iodine the population is receiving and acting to ensure at-risk groups receive enough iodine in the diet.”

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The Endocrine Society’s clinical practice guidelines on managing thyroid dysfunction during pregnancy and postpartum, including iodine supplementation, are available at http://www.endo-society.org/guidelines/upload/Thyroid-Exec-Summ.pdf.

Other researchers working on the study include: P. Otahal, I. Hay and J. Burgess of the University of Tasmania.

The article, “Mild Iodine Deficiency During Pregnancy is Associated with Reduced Educational Outcomes in the Offspring: 9-Year Follow-Up of the Gestational Iodine Cohort,” appears in the May 2013 issue of JCEM.

Founded in 1916, The Endocrine Society is the world’s oldest, largest and most active organization devoted to research on hormones and the clinical practice of endocrinology.  Today, The Endocrine Society’s membership consists of over 16,000 scientists, physicians, educators, nurses and students in more than 100 countries. Society members represent all basic, applied and clinical interests in endocrinology. The Endocrine Society is based in Chevy Chase, Maryland. To learn more about the Society and the field of endocrinology, visit our site at http://www.endo-society.org. Follow us on Twitter at https://twitter.com/#!/EndoMedia.

Common osteoporosis drug slows formation of new bone

Contact: Jenni Glenn Gingery jgingery@endo-society.org 301-941-0240 The Endocrine Society

Study results suggest combination treatments may be needed to stop bone loss, fuel growth

Chevy Chase, MD––Although the drug zoledronic acid slows bone loss in osteoporosis patients, it also boosts levels of a biomarker that stops bone formation, according to a recent study accepted for publication in The Endocrine Society’s Journal of Clinical Endocrinology & Metabolism (JCEM).

Osteoporosis weakens bones and increases the risk patients will suffer fractures. The findings suggest combination therapy may be a more effective approach to battling this common condition.

“The key to effectively treating osteoporosis lies in increasing bone mass,” said the study’s lead author, Antonino Catalano, MD, PhD, of the University of Messina in Italy. “Zoledronic acid halts bone loss, but it also signals the body to stop forming new bone mass. The drug may need to be combined with other treatments to add bone mass.”

The prospective intervention study followed the treatment of 40 postmenopausal women at an ambulatory care center. Half of the women received zoledronic acid, and half received a placebo. Levels of sclerostin – a biomarker that inhibits bone formation – increased among the participants who were treated with zoledronic acid.

“The data points to an opportunity to increase bone mass by combining zoledronic acid with a drug that suppresses the resulting sclerostin’s effect,” Catalano said. “An innovative combination therapy using zoledronic acid and selective antibodies to block the sclerostin could simultaneously stop bone loss and encourage new bone formation. This is an important avenue for researchers to explore as they develop new osteoporosis treatments.”

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Other researchers working on the study include: N. Morabito, G. Basile, S. Brancatelli, D. Cucinotta and A. Lasco of the University of Messina.

The article, “Zoledronic Acid Acutely Increases Sclerostin Serum Levels in Women with Postmenopausal Osteoporosis,” appears in the May 2013 issue of JCEM.

Founded in 1916, The Endocrine Society is the world’s oldest, largest and most active organization devoted to research on hormones and the clinical practice of endocrinology.  Today, The Endocrine Society’s membership consists of over 16,000 scientists, physicians, educators, nurses and students in more than 100 countries. Society members represent all basic, applied and clinical interests in endocrinology. The Endocrine Society is based in Chevy Chase, Maryland. To learn more about the Society and the field of endocrinology, visit our site at http://www.endo-society.org. Follow us on Twitter at https://twitter.com/#!/EndoMedia.

Early life exposure to BPA may affect testis function in adulthood

2010 study posted for filing

 

Exposure to environmental levels of the industrial chemical bisphenol A, or BPA, in the womb and early life may cause long-lasting harm to testicular function, according to a new study conducted in animals. The results are being presented Monday at The Endocrine Society’s 92nd Annual Meeting in San Diego.

 

“We are seeing changes in the testis function of rats after exposure to BPA levels that are lower than what the Food and Drug Administration and Environmental Protection Agency consider safe exposure levels for humans,” said Benson Akingbemi, PhD, the study’s lead author and an associate professor at Auburn (Ala.) University. “This is concerning because large segments of the population, including pregnant and nursing mothers, are exposed to this chemical.”

 

Many hard plastic bottles and canned food liners contain BPA, as do some dental sealants. BPA acts in a similar manner as the female sex hormone estrogen and has been linked to female infertility. This chemical is present in placenta and is able to pass from a mother into her breast milk. In their study of the male, Akingbemi and colleagues saw harmful effects of BPA at the cellular level, specifically in Leydig cells. These cells in the testis secrete testosterone, the main sex hormone that supports male fertility. After birth, Leydig cells gradually acquire the capacity for testosterone secretion, Akingbemi explained.

 

The process of testosterone secretion was decreased in male offspring of female rats that received BPA during pregnancy and while nursing. The mothers were fed BPA in olive oil at a dose of either 2.5 or 25 micrograms of BPA per kilogram of body weight. Akingbemi said this is below the daily upper limit of safe exposure for humans, which federal guidelines currently put at 50 micrograms per kilogram of body weight. A control group of pregnant rats received olive oil without BPA. Male offspring, after weaning at 21 days of age, received no further exposure to BPA.

 

Using a combination of analytical methods, the investigators studied the development of Leydig cells in male offspring. The capacity for testosterone secretion was assessed at 21, 35 and 90 days of age. The amount of testosterone secreted per Leydig cell was found to be much lower in male offspring after early-life exposure to BPA than in offspring from control unexposed animals.

 

“Although BPA exposure stopped at 21 days of age, BPA’s effects on Leydig cells, which were seen immediately at the end of exposure and at 35 days, remained apparent until 90 days of age, when the rats reached adulthood,” Akingbemi said. “Therefore, the early life period is a sensitive window of exposure to BPA and exposure at this time may affect testis function into adulthood.”

Progesterone (NOT Progestin) is effective for hot flash treatment and provides an alternative to estrogen

2010 study posted for filing

 

Postmenopausal women who experience bothersome hot flashes or night sweats may have an alternative treatment to estrogen. According to a new study, oral micronized progesterone relieves those symptoms. The results will be presented Saturday at The Endocrine Society’s 92nd Annual Meeting in San Diego.

 

“This is the first evidence that oral micronized progesterone, which is molecularly identical to the natural hormone, is effective for women with symptomatic hot flashes,” said the presenting author, Jerilynn Prior, MD, professor, University of British Columbia, Vancouver, Canada.

 

Available only by prescription and sold under the brand name Prometrium in the United States and Canada, this form of progesterone is manufactured from a steroid in yams.

 

“Vasomotor symptoms”—hot flashes (sometimes called hot flushes) and night sweats—are experienced by most women during the years around the final menstrual period. In the most symptomatic women (at least 5-10%) these symptoms disturb sleep, energy and quality of life, Prior said.

 

The researchers recruited 114 healthy postmenopausal women seeking hormonal therapy for hot flashes and night sweats and randomly assigned them to take either oral micronized progesterone or an inactive substance (placebo), both as three round capsules at bedtime. Neither the women nor the study team members were aware which treatment the study participants received during the three months of therapy. The time since their last menstrual flow was one to 10 years, with an average of four years. To be eligible to participate in the study, women could not have taken ovarian hormone therapy within the past six months.

 

Prior and Christine Hitchcock, PhD, of the University of British Columbia, calculated the average daily vasomotor symptom score, or VMSScore, from the data that subjects recorded in a daily diary. This score reflects both intensity and number for hot flashes and night sweats each day.

 

Progesterone, in a 300-milligram dose, was more effective than placebo at decreasing the intensity and number of symptoms, the authors reported, and the difference was both statistically significant and clinically important. The 68 women taking progesterone showed a 56% improvement from baseline in VMSScore, and a 48% reduction in the number of VMS; the 46 women taking placebo had 28% lower VMSScores and a 22% reduction in number.

 

“Women improve very quickly on oral micronized progesterone. The improvement is apparent within the first 4 weeks,” Prior said.

 

Micronized progesterone did not cause any serious side effects, she said. The drug may be an option for postmenopausal women who do not want to or should not take estrogen—”currently the only effective therapy for decreasing severe vasomotor symptoms,” Prior said.

Early life exposure to BPA may affect testis function in adulthood

2010  study posted for filing

Contact: Aaron Lohr alohr@endo-society.org 240-482-1380 The Endocrine Society

Exposure to environmental levels of the industrial chemical bisphenol A, or BPA, in the womb and early life may cause long-lasting harm to testicular function, according to a new study conducted in animals. The results are being presented Monday at The Endocrine Society’s 92nd Annual Meeting in San Diego.

“We are seeing changes in the testis function of rats after exposure to BPA levels that are lower than what the Food and Drug Administration and Environmental Protection Agency consider safe exposure levels for humans,” said Benson Akingbemi, PhD, the study’s lead author and an associate professor at Auburn (Ala.) University. “This is concerning because large segments of the population, including pregnant and nursing mothers, are exposed to this chemical.”

Many hard plastic bottles and canned food liners contain BPA, as do some dental sealants. BPA acts in a similar manner as the female sex hormone estrogen and has been linked to female infertility. This chemical is present in placenta and is able to pass from a mother into her breast milk. In their study of the male, Akingbemi and colleagues saw harmful effects of BPA at the cellular level, specifically in Leydig cells. These cells in the testis secrete testosterone, the main sex hormone that supports male fertility. After birth, Leydig cells gradually acquire the capacity for testosterone secretion, Akingbemi explained.

The process of testosterone secretion was decreased in male offspring of female rats that received BPA during pregnancy and while nursing. The mothers were fed BPA in olive oil at a dose of either 2.5 or 25 micrograms of BPA per kilogram of body weight. Akingbemi said this is below the daily upper limit of safe exposure for humans, which federal guidelines currently put at 50 micrograms per kilogram of body weight. A control group of pregnant rats received olive oil without BPA. Male offspring, after weaning at 21 days of age, received no further exposure to BPA.

Using a combination of analytical methods, the investigators studied the development of Leydig cells in male offspring. The capacity for testosterone secretion was assessed at 21, 35 and 90 days of age. The amount of testosterone secreted per Leydig cell was found to be much lower in male offspring after early-life exposure to BPA than in offspring from control unexposed animals.

“Although BPA exposure stopped at 21 days of age, BPA’s effects on Leydig cells, which were seen immediately at the end of exposure and at 35 days, remained apparent until 90 days of age, when the rats reached adulthood,” Akingbemi said. “Therefore, the early life period is a sensitive window of exposure to BPA and exposure at this time may affect testis function into adulthood.”

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Funding from this study came in part from the Graduate Research Scholars Program of Alabama EPSCoR (Experimental Program to Stimulate Competitive Research), Tuscaloosa, Ala., and the National Institute of Environmental Health Sciences.

Prenatal exposure to endocrine-disrupting chemicals linked to breast cancer

2010 study for filing
Contact: Aaron Lohr
alohr@endo-society.org
240-482-1380
The Endocrine Society

A study in mice reveals that prenatal exposure to endocrine-disrupting chemicals, like bisphenol-A (BPA) and diethylstilbestrol (DES), may program a fetus for life. Therefore, adult women who were exposed prenatally to BPA or DES could be at increased risk of breast cancer, according to a new study accepted for publication in Hormones & Cancer, a journal of The Endocrine Society.

Endocrine-disrupting chemicals are substances in the environment that interfere with hormone biosynthesis, metabolism or action resulting in adverse developmental, reproductive, neurological and immune effects in both humans and wildlife. These chemicals are designed, produced and marketed largely for specific industrial purposes.

“BPA is a weak estrogen and DES is a strong estrogen, yet our study shows both have a profound effect on gene expression in the mammary gland (breast) throughout life,” said Hugh Taylor, MD, of the Yale University School of Medicine in New Haven, Conn. and lead author of the study. “All estrogens, even ‘weak’ ones can alter the development of the breast and ultimately place adult women who were exposed to them prenatally at risk of breast cancer.”

In this study, researchers treated pregnant mice with BPA or DES and then looked at the offspring as adults. When the offspring reached adulthood, their mammary glands still produced higher levels of EZH2, a protein that plays a role in the regulation of all genes. Higher EZH2 levels are associated with an increased risk of breast cancer in humans.

“We have demonstrated a novel mechanism by which endocrine-disrupting chemicals regulate developmental programming in the breast,” said Taylor. “This study generates important safety concerns about exposures to environmental endocrine disruptors such as BPA and suggests a potential need to monitor women exposed to these chemicals for the development of breast lesions as adults.”

 

 

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Other researchers working on the study include Leo Doherty, Jason Bromer, Yuping Zhou and Tamir Aldad of the Yale University School of Medicine in New Haven, Connecticut.

The article, “In Utero Exposure to Diethylstilbestrol (DES) or Bisphenol-A (BPA) Increases EZH2 Expression in the Mammary Gland: An Epigenetic Mechanism Linking Endocrine Disruptors to Breast Cancer,” has been published online and can be found at: http://www.springerlink.com/content/547256j0g02073v5/?p=286f52b5d3c94d9f8dc4546af408af89π=0.

Founded in 1916, The Endocrine Society is the world’s oldest, largest and most active organization devoted to research on hormones and the clinical practice of endocrinology. Today, The Endocrine Society’s membership consists of over 14,000 scientists, physicians, educators, nurses and students in more than 100 countries. Society members represent all basic, applied, and clinical interests in endocrinology. The Endocrine Society is based in Chevy Chase, Maryland. To learn more about the Society and the field of endocrinology, visit our site at www.endo-society.org.

BPA shown to disrupt thyroid function in pregnant animals and offspring

Contact: Aaron Lohr
alohr@endo-society.org
240-482-1380
The Endocrine Society

New study uses animal model similar to humans and shows BPA can affect thyroid function

Chevy Chase, MD –– In utero exposure to bisphenol A (BPA) can be associated with decreased thyroid function in newborn sheep, according to a recent study accepted for publication in Endocrinology, a journal of The Endocrine Society. Hypothyroidism is characterized by poor mental and physical performance in human adults and in children can result in cognitive impairment and failure to grow normally.

BPA, a major molecule used in the plastic industry, has been shown to be an endocrine disruptor that could exert deleterious effects on human health. Most investigations have focused on reproductive functions, but there is evidence that BPA might have negative effects on other endocrine systems including thyroid function. The current study used sheep, a relevant model for human pregnancy and thyroid regulation and ontogeny, and analyzed the internal exposures of the fetuses and their mothers to BPA and determined to what extent those exposures may be associated with thyroid disruption.

“Our study is the first to show that BPA can alter thyroid function of pregnant animals and their offspring in a long-gestation species with similar regulation of thyroid function as humans,” said Catherine Viguié, PhD, of Toxalim, Research Centre in Food Toxicology in Toulouse, France and lead author of the study. “Because of the potential consequences of maternal/fetal thyroid disruption on neural and cognitive development, we think that our study warrants the need for further investigations on the effect of BPA on thyroid function.”

This study was conducted on adult ewes that had multiple pregnancies before being included in the experiment. Some of the pregnant ewes received daily subcutaneous injections of BPA while the remainder were allocated to the control group. Blood samples were taken from jugular blood, amniotic fluid, placenta samples and cord blood to determine levels of BPA, thyroid-stimulating hormone (TSH) and thyroxine. Results showed that maternal and fetal exposure to BPA was associated with disruption of thyroid function of both the pregnant ewes throughout pregnancy and the newborns as characterized by a decrease in circulating thyroxine levels.

“BPA concentrations in the mother blood in this experiment were fluctuating between injections from 15 to 1 time the highest blood levels reported in pregnant women in the literature,” notes Viguié. “As a consequence, although this study clearly indicates that BPA has the potential to alter thyroid function in living pregnant animals and their offspring, it cannot be considered as fully conclusive in terms of risk for human health in the actual conditions of exposure of human populations.”

“In other words, although our study clearly indicates that BPA-induced thyroid disruption is possible, it does not indicate how probable such a disruption is to occur in real conditions,” added Viguié. “Thus, the main merit of our work is to encourage others, including epidemiologists, to scrutinize and qualify carefully such a probability.”

 

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Other researchers working on the study include: Séverine Collet, Véronique Gayrard, Nicole Picard-Hagen, Sylvie Puel, Béatrice Roques, Pierre-Louis Toutain and Marlène Lacroix of Institut National de la Recherche Agronomique (INRA), Toxalim, and the Ecole Nationale Vétérinaire de Toulouse (ENVT), Université de Toulouse in France.

The article, “Maternal and fetal exposure to bisphenol A is associated to alterations of thyroid function in pregnant ewes and their newborn lambs,” appears in the January 2013 issue of Endocrinology.

Founded in 1916, The Endocrine Society is the world’s oldest, largest and most active organization devoted to research on hormones and the clinical practice of endocrinology. Today, The Endocrine Society’s membership consists of over 15,000 scientists, physicians, educators, nurses and students in more than 100 countries. Society members represent all basic, applied and clinical interests in endocrinology. The Endocrine Society is based in Chevy Chase, Maryland. To learn more about the Society and the field of endocrinology, visit our site at www.endo-society.org. Follow us on Twitter at https://twitter.com/#!/EndoMedia.

Common antidepressant drugs linked to lactation difficulties in moms

2010 study posted for filing

Contact: Aaron Lohr alohr@endo-society.org 240-482-1380 The Endocrine Society

According to a new study accepted for publication in The Endocrine Society’s Journal of Clinical Endocrinology & Metabolism (JCEM), women taking commonly used forms of antidepressant drugs may experience delayed lactation after giving birth and may need additional support to achieve their breastfeeding goals.

Breastfeeding benefits both infants and mothers in many ways as breast milk is easy to digest and contains antibodies that can protect infants from bacterial and viral infections. The World Health Organization recommends that infants should be exclusively breastfed for the first six months of life. This new study shows that certain common antidepressant drugs may be linked to a common difficulty experienced by new mothers known as delayed secretory activation, defined as a delay in the initiation of full milk secretion.

“The breasts are serotonin-regulated glands, meaning the breasts’ ability to secrete milk at the right time is closely related to the body’s production and regulation of the hormone serotonin,” said Nelson Horseman, PhD, of the University of Cincinnati and co-author of the study. “Common antidepressant drugs like fluoxetine, sertraline and paroxetine are known as selective serotonin reuptake inhibitor (SSRI) drugs and while they can affect mood, emotion and sleep they may also impact serotonin regulation in the breast, placing new mothers at greater risk of a delay in the establishment of a full milk supply.”

In this study, researchers examined the effects of SSRI drugs on lactation using laboratory studies of human and animal cell lines and genetically modified mice. Furthermore, an observational study evaluated the impact of SSRI drugs on the onset of milk production in postpartum women. In this study of 431 postpartum women, median onset of lactation was 85.8 hours postpartum for the SSRI-treated mothers and 69.1 hours for mothers not treated with SSRI drugs. Researchers commonly define delayed secretory activation as occurring later than 72 hours postpartum.

“SSRI drugs are very helpful medications for many moms, so understanding and ameliorating difficulties moms experience can help them achieve their goals for breastfeeding their babies,” said Horseman. “More human research is needed before we can make specific recommendations regarding SSRI use during breastfeeding.”

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Other researchers working on the study include: Aaron Marshall, Laura Hernandez and Karen Gregerson of the University of Cincinnati in Ohio; Laurie Nommsen-Rivers of Cincinnati Children’s Hospital Medical Center in Ohio; Kathryn Dewey of the University of California at Davis; and Caroline Chantry of the University of California Davis Medical Center in Sacramento.

The article, “Serotonin transport and metabolism in the mammary gland modulates secretory activation and involution,” will appear in the February 2010 issue of JCEM.

Founded in 1916, The Endocrine Society is the world’s oldest, largest and most active organization devoted to research on hormones and the clinical practice of endocrinology. Today, The Endocrine Society’s membership consists of over 14,000 scientists, physicians, educators, nurses and students in more than 100 countries. Society members represent all basic, applied, and clinical interests in endocrinology. The Endocrine Society is based in Chevy Chase, Maryland. To learn more about the Society and the field of endocrinology, visit our site at www.endo-society.org.

Nearly 80 Million Americans Won’t Need Vitamin D Supplements Under New Guidelines

Engineering Evil: There is Absolutely No Current Solid Scientific Basis for the IOM’s recommendation:

  • Current guidelines
  • Normal: equal to or greater than 32 nanograms per milliliter (ng/mL)
  • Insufficient: less than 32 ng/mL
  • Deficient: less than 20 ng/mL
  • When Vitamin D levels in the bloodstream is at or less than 20 ng/ml the bone starts to become brittle in adults and in kids it causes rickets
  • Instead of attempting to improve the nutrient profile of the public. The IOM just dropped the numbers in order to claim success.
  • The IOM claims their opinion is based upon 1000 published studies. They are either not recent studies, or there are other negative issues.

Now Please continue reading at your own risk

ScienceDaily (Oct. 24, 2012) — Nearly 80 million Americans would no longer need to take vitamin D supplements under new Institute of Medicine guidelines, according to a study by Loyola University Chicago Stritch School of Medicine researchers.

Results were published Oct. 24, 2012 in the journal PLOS ONE.

The new guidelines advise that almost all people get sufficient vitamin D when their blood levels are at or above 20 nanograms per milliliter (ng/ml). Older guidelines said people needed vitamin D levels above 30 ng/ml.

Holly Kramer, MD, MPH and colleagues examined data from 15,099 non-institutionalized adults who participated in the Third National Health and Nutrition Examination Study (NHANES III). The sample included 1,097 adults who had chronic kidney disease, which has been linked to low vitamin D levels.

In the survey population, 70.5 percent of adults with healthy kidneys had vitamin D blood levels that would be considered insufficient under the older guidelines. But under the newer Institute of Medicine guidelines, only 30.3 percent of these adults had insufficient vitamin D levels.

Among adults with chronic kidney disease, 76.5 percent had insufficient vitamin D under the older guidelines, while only 35.4 percent had insufficient levels under the Institute of Medicine guidelines.

Because NHANES III is a representative sample, researchers were able to extrapolate results to the general population. Kramer and colleagues estimate that a total of 78.7 million adults considered to have insufficient vitamin D levels under the older guidelines would now have sufficient levels under the Institute of Medicine guidelines. “The new guidelines have an impact on a large proportion of the population,” Kramer said.

The Institute of Medicine guidelines are based on nearly 1,000 published studies and testimony from scientists and other experts. (The Institute of Medicine committee that wrote the new guidelines for vitamin D and calcium includes Ramon Durazo-Arvizu, PhD, a professor in Loyola’s Department of Preventive Medicine and Epidemiology).

The Institute of Medicine committee found that vitamin D is essential to avoid poor bone health, such as rickets. But there have been conflicting and mixed results in studies on whether vitamin D can also protect against cancer, heart disease, autoimmune diseases and diabetes, the Institute of Medicine committee found. Moreover, excessive vitamin D can damage the kidneys and heart, the committee reported.

However, the Institute of Medicine guidelines are controversial. For example, the Endocrine Society continues to endorse the older guidelines. Kramer said that people who are confused about how much vitamin D they need should consult with their doctors.

Kramer is first author of the study, which was funded by the National Institutes of Health. She is an associate professor in Loyola’s Department of Preventive Medicine and Epidemiology and Department of Medicine, Division of Nephrology and Hypertension. Her co-authors are Durazo-Arvizu; Guichan Cao, MS; Amy Luke, PhD; David Shoham, PhD; and Richard Cooper, PhD of Loyola’s Department of Preventive Medicine and Epidemiology and Chris Sempos, PhD of the National Institutes of Health’s Office of Dietary Supplements

Bisphenol A exposure in pregnant mice permanently changes DNA of offspring

2009 study posted for filing

Contact: Aaron Lohr
alohr@endo-society.org
240-482-1380
The Endocrine Society

Exposure during pregnancy to the chemical bisphenol A, or BPA, found in many common plastic household items, is known to cause a fertility defect in the mother’s offspring in animal studies, and now researchers have found how the defect occurs. The results of the new study will be presented Saturday at The Endocrine Society’s 91st Annual Meeting in Washington, D.C.

The study, funded partly by the National Institutes of Health, joins a growing body of animal research showing the toxic health effects of BPA, including reproductive and developmental problems. Last August the U.S. Food and Drug Administration found BPA to be safe as currently used but later said more research on its safety is needed. BPA is used to make hard polycarbonate plastic, such as for baby bottles, refillable water bottles and food containers, as well as to make the linings of metal food cans.

BPA has estrogen-like properties and in pregnant animals has been linked to female infertility.

“The big mystery is how does exposure to this estrogen-like substance during a brief period in pregnancy lead to a change in uterine function,” said study co-author Hugh Taylor, MD, professor and chief of the reproductive endocrinology section at Yale University School of Medicine.

To find the answer to that question, Taylor and his co-workers at Yale injected pregnant mice with a low dose of BPA on pregnancy days 9 to 16. After the mice gave birth, the scientists analyzed the uterus of female offspring and extracted DNA.

They found that BPA exposure during pregnancy had a lasting effect on one of the genes that is responsible for uterine development and subsequent fertility in both mice and humans (HOXA10). Furthermore, these changes in the offspring’s uterine DNA resulted in a permanent increase in estrogen sensitivity. The authors believe that this process causes the overexpression of the HOXA10 gene in adult mice that they found in previous studies.

The permanent DNA changes in the BPA-exposed offspring were not apparent in the offspring of mice that did not receive BPA injection (the controls). This finding demonstrates that the fetus is sensitive to BPA in mice and likely also in humans, Taylor said.

“We don’t know what a safe level of BPA is, so pregnant women should avoid BPA exposure,” Taylor said. “There is nothing to lose by avoiding items made with BPA—and maybe a lot to gain.”

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BPA may cause heart disease in women, research shows

2009 study posted for filing

Contact: Katie Pence
katie.pence@uc.edu
513-558-4561
University of Cincinnati Academic Health Center

CINCINNATI—New research by a team of scientists at the University of Cincinnati (UC) shows that bisphenol A (BPA) may be harmful for the heart, particularly in women.

Results of several studies are being presented in Washington, D.C., at ENDO 09, the Endocrine Society’s annual meeting, June 10-13.

A research team lead by Scott Belcher, PhD, Hong Sheng Wang, PhD, and Jo El Schultz, PhD, in the department of pharmacology and cell biophysics, found that exposure to BPA and/or estrogen causes abnormal activity in hearts of female rats and mice.

In addition, these researchers found that estrogen receptors are responsible for this affect in heart muscle cells.

“There is broad exposure to bisphenol A, despite recognition that BPA can have harmful effects,” Belcher says. “We had reason to believe that harmful cardiovascular affects can be added to the list.”

BPA, an environmental pollutant with estrogen activity, is used to make hard, clear plastic and is common in many food product containers. It has been linked to neurological defects, diabetes and breast and prostate cancer.

Using live cultures of cells isolated from rat or mouse hearts, researchers briefly exposed the cardiac cells to BPA and/or estrogen. Both compounds caused striking changes in the activity of cardiac muscle cells from females but not males. Additional studies revealed that these cellular changes in activity caused improperly controlled beating in the female heart.

“Low doses of BPA markedly increased the frequency of arrhythmic events,” Belcher says. “The effect of BPA on these cardiac arrhythmias was amplified when exposed to estradiol, the major estrogen hormone in humans.”

The mechanism underlying this harmful effect was investigated using cellular imaging techniques.

“BPA and/or estrogen rapidly stimulated contraction by altering control of the concentrations of free calcium inside the heart cell but only in heart muscle cells from females, showing that these effects were sex-specific,” Belcher says. “BPA’s presence increased the frequency of calcium ‘sparks’ from the sarcoplasmic reticulum—the part of the cardiac muscle that stores and releases calcium ions—indicating spontaneous release or ‘leak’ that’s likely causing the heart arrhythmias and may have other harmful actions, especially following heart attack.”

Belcher and colleagues also investigated the nature of the mechanisms that mediated the responses of the cardiac muscle cells to estrogen and BPA.

“Pharmacological studies using selective estrogen receptor drugs and animal models lacking estrogen receptors were used to investigate the role of each estrogen receptor in mediating the rapid sex-specific function effects of E2 and BPA in cells,” he says. “Our findings suggest that estrogen has opposing actions in cardiac cells.

“In female cardiac muscle cells, the blocking or genetic removal of estrogen receptor beta completely blocked the contractile effects of BPA and estrogen, while in males, blockade of the effects of estrogen receptor alpha caused the male heart to become more ‘female-like’ and become responsive to estrogen and BPA.

“These studies have identified new and important potential cardiac risks associated with BPA exposure that may be especially important for women’s heart health,” he says.

 

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This study was funded by grants from the National Institutes of Health and the UC Center for Environmental Genetics.

Gestational exposure to urban air pollution linked to vitamin D deficiency in newborns

Contact: Aaron Lohr alohr@endo-society.org 240-482-1380 The Endocrine Society

New study highlights potential importance of vitamin D supplementation in pregnant women

Chevy Chase, MD—Gestational exposure to ambient urban air pollution, especially during late pregnancy, may contribute to lower vitamin D levels in offspring, according to a recent study accepted for publication in The Endocrine Society’s Journal of Clinical Endocrinology and Metabolism (JCEM). According to study authors, this could affect the child’s risk of developing diseases later in life.

Recent data have demonstrated that maternal vitamin D deficiency during pregnancy may have an influence on the development of asthma and allergic diseases in offspring. A number of factors may influence vitamin D supply in women. Exposure to high levels of air pollution has been suggested as a contributor to vitamin D deficiency in adults and children.

“We investigated the associations between gestational exposure to urban air pollutants and vitamin D cord blood serum level,” said Nour Baïz, MASc, of Intitut National de la Santé et de la Recherche Médicale (INSERM) in Paris, France who led the study. “Our findings show for the first time, that exposure to ambient air pollution comparable to current World Health Organization standards might contribute to vitamin D deficiency in newborns.”

In this study, researchers investigated the associations between gestational exposure to urban air pollutants and 25-hydroxyvitamin D cord blood serum level in 375 mother-child pairs. Maternal exposure to urban levels of nitrogen dioxide and particulate matter less than 10 micro meters during the whole pregnancy was a strong predictor of low vitamin D status in newborns. The association between gestational exposure to air pollutants and vitamin D deficiency in newborns was strongest for third-trimester exposures.

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Other researchers participating in the study included: Isabella Annesi-Maesano of INSERM; Patricia Dargent-Molina of University Pierre and Marie Curie in Paris, France; John Wark of The Royal Melbourne Hospital in Victoria, Australia; Jean-Claude Souberbielle of Université Paris-Descartes in Paris, France; and Rémy Slama of Institut Albert Bonniot in Grenoble, France.

The article “Gestational Exposure to Urban Air Pollution Related to a Decrease in Cord Blood Vitamin D Levels” is slated to appear in the November 2012 issue of JCEM.

Founded in 1916, The Endocrine Society is the world’s oldest, largest and most active organization devoted to research on hormones and the clinical practice of endocrinology.  Today, The Endocrine Society’s membership consists of over 15,000 scientists, physicians, educators, nurses and students in more than 100 countries. Society members represent all basic, applied and clinical interests in endocrinology. The Endocrine Society is based in Chevy Chase, Maryland. To learn more about the Society and the field of endocrinology, visit our site at www.endo-society.org. Follow us on Twitter at https://twitter.com/#!/EndoMedia.

High-fructose corn syrup sugar makes maturing human fat cells fatter, less insulin-sensitive

Contact: Aaron Lohr alohr@endo-society.org 240-482-1380 The Endocrine Society

Fructose, the sugar widely used as high-fructose corn syrup in soft drinks and processed foods, often gets some of the blame for the widespread rise in obesity. Now a laboratory study has found that when fructose is present as children’s fat cells mature, it makes more of these cells mature into fat cells in belly fat and less able to respond to insulin in both belly fat and fat located below the skin.

The results will be presented Sunday at The Endocrine Society’s 92nd Annual Meeting in San Diego by lead author Georgina Coade, a PhD student at the University of Bristol in the U.K.

“Our results suggest that high levels of fructose, which may result from eating a diet high in fructose, throughout childhood may lead to an increase in visceral [abdominal] obesity, which is associated with increased cardiometabolic risk,” Coade said.

Defined by a large waistline, abdominal obesity raises the risk of heart disease and Type 2 diabetes. The abdominal cavity contains one of two major types of fat in the body: visceral fat. The other type, subcutaneous fat, is found below the surface of the skin.

Although researchers have shown the negative effects of fructose on the fat distribution of rodents, the effects of this sugar on human adipocytes, or fat cells, are not clear, according to Coade. Therefore, she and her fellow researchers studied biopsy specimens of both subcutaneous and visceral fat from 32 healthy-weight children who had not yet gone through puberty.

From the biopsy samples, the investigators obtained preadipocytes—the precursors to fat cells that have the potential to differentiate, or mature, into fat-containing adipocytes. They then allowed the precursor cells to mature for 14 days in culture media containing normal glucose (the main sugar found in the bloodstream and the principal source of energy in the body), high glucose or high fructose. The researchers assessed cell differentiation by measuring activity of an enzyme (GPDH) and the abundance of the adipocyte fatty acid binding protein, which are both present only in mature fat cells.

Fructose, the research team found, had different effects to that of glucose and caused the fat cells to differentiate more—that is, to form more mature fat cells—but only in visceral fat.

For both types of fat cells, maturation in fructose decreased the cells’ insulin sensitivity, which is the ability to successfully take up glucose from the bloodstream into fat and muscles. Decreased insulin sensitivity is a characteristic of Type 2 diabetes.

Although prolonged exposure to fructose had a negative effect on insulin sensitivity, when Coade and her co-workers exposed mature fat cells, rather than preadipocytes, to fructose for 48 hours, the cells’ insulin sensitivity increased. The reason why is unknown. However, she said, “Fructose alters the behavior of human fat cells if it is present as the fat cells mature. We can maybe compare this [timing] to periods in children when they are making their fat.”

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The London-based organization Diabetes UK helped fund this study.

BPA exposure in utero may increase predisposition to breast cancer

Contact: Aaron Lohr alohr@endo-society.org 240-482-1380 The Endocrine Society

Study finds perinatal exposure to BPA has effect on mammary hormone response

Chevy Chase, MD—A recent study accepted for publication in Molecular Endocrinology, a journal of The Endocrine Society, found that perinatal exposure to environmentally relevant doses of bisphenol A (BPA) alters long-term hormone response and breast development in mice that may increase the propensity to develop cancer.

BPA, a man-made chemical produced and marketed largely for specific industrial purposes, is detected in body fluids of more than 90 percent of the human population. It was originally synthesized as an estrogenic compound and there has been concern that exposure to BPA could have developmental effects on various hormone-responsive organs including the mammary gland.

“I want it to be clear that we do not provide evidence that BPA exposure causes breast cancer per se,” said Cathrin Brisken, MD, of the Swiss Institute for Experimental Cancer Research and co-author of the study. “We do provide evidence that BPA exposure alters mammary gland development and that this may increase the predisposition of the breast to breast cancer.”

In this study, researchers mimicked human exposure to BPA as it occurs with beverages and food from BPA containing vessels (such as plastics and the lining of tin cans) by adding the compound to the drinking water of breeding mice. Female pups born from BPA-consuming parents were transferred to a BPA-free environment at weaning and followed over time.

Researchers analyzed changes in the mammary gland of female offspring that were exposed to BPA through their mothers in utero and while being breast fed. The mammary glands of BPA exposed females showed an increased response to the hormone progesterone. Lifetime exposure to progesterone has been linked to increase breast cancer risk.

Furthermore, researchers  found that adult females who had been exposed to BPA in utero and while breast fed, showed a 1.5 fold increase in cell numbers in their milk ducts. This is comparable to what is seen upon similar exposure to another estrogenic compound, diethyllbestrol (DES). Uterine exposure to DES in the human population has been shown to increase the relative risk of getting breast cancer two-fold as women reach their fifties.

“While we cannot extrapolate these results directly from mice to humans, the possibility that some of the increase in breast cancer incidence observed over the past decades may be attributed to exposure to BPA cannot be dismissed,” said Brisken. “Our study suggests that pregnant and breastfeeding mothers should avoid exposure to BPA as it may affect their daughters’ breast tissue.”

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Other researchers working on the study include Ayyakkannu Ayyanan, Ouahiba Laribi, Sonia Schuepbach-Mallepell, Christina Schrick, Maria Gutierrez, Tamara Tanos and Ozden Yalcin-Ozuysal of the Swiss Institute for Experimental Cancer Research; and Gregory Lefebvre and Jacques Rougemont of École polytechnique fédérale de Lausanne in Switzerland.

The article, “Perinatal exposure to bisphenol A increases adult mammary gland progesterone response and cell number,” appears in the November 2011 issue of Molecular Endocrinology.

Founded in 1916, The Endocrine Society is the world’s oldest, largest and most active organization devoted to research on hormones and the clinical practice of endocrinology.  Today, The Endocrine Society’s membership consists of over 14,000 scientists, physicians, educators, nurses and students in more than 100 countries. Society members represent all basic, applied and clinical interests in endocrinology. The Endocrine Society is based in Chevy Chase, Maryland. To learn more about the Society and the field of endocrinology, visit our site at www.endo-society.org.

Phthalate, environmental chemical is linked to higher rates of childhood obesity

Obese children show greater exposure than nonobese children to a phthalate, a chemical used to soften plastics in some children’s toys and many household products, according to a new study, which found that the obesity risk increases according to the level of the chemical found in the bloodstream. The study will be presented Saturday at The Endocrine Society‘s 94th Annual Meeting in Houston.

The chemical, di-ethylhexyl phthalate (DEHP), is a common type of phthalate, a group of industrial chemicals that are suspected endocrine disruptors, or hormone-altering agents.

In the study, children with the highest DEHP levels had nearly five times the odds of being obese compared with children who had the lowest DEHP levels, study co-author Mi Jung Park, MD, PhD, said.

“Although this study cannot prove causality between childhood obesity and phthalate exposure, it alerts the public to recognize the possible harm and make efforts to reduce this exposure, especially in children,” said Park, a pediatric endocrinologist in Seoul, Korea, at Sanggye Paik Hospital and professor at Inje University College of Medicine.

Phthalates are found in some pacifiers, plastic food packages, medical equipment and building materials such as vinyl flooring, and even in nonplastic personal care products, including soap, shampoo and nail polish.

Prior research has shown that phthalates may change gene expression associated with fat metabolism, according to Dr. Park. Because past research suggested a link between concentrations of phthalate metabolites and increased waist size in adults, her group studied a possible connection with childhood obesity.

Dr.Park and colleagues measured serum levels of DEHP in 204 children: 105 obese and 99 healthy-weight youth ages 6 to 13 years. The researchers divided these DEHP measurements into four groups from the lowest detectable level (40.2 nanograms per milliliter, or ng/mL) to the highest (69.7 to 177.1 ng/mL).

They found that the obese children had a significantly higher average DEHP level than did the nonobese controls (107 versus 53.8 ng/mL, respectively). In particular, a high DEHP level correlated with body mass index and percentage of fat mass. This increased risk of obesity with elevation of DEHP levels was independent of factors such as physical activity and daily calorie intake, according to the authors.

“More research in people is needed to determine whether DEHP exposure contributes to childhood obesity,” Dr.Park said