Testosterone levels do not naturally decline

Testosterone levels do not naturally decline

Researchers searching for reference ranges for testosterone levels among age groups discovered that there may not be a rationale for any decline in testosterone due to age alone.
Citations:
Harmonized Reference Ranges for Circulating Testosterone Levels in Men of Four Cohort Studies in the United States and Europe The Journal of Clinical Endocrinology & Metabolism, Volume 102, Issue 4, 1 April 2017, Pages 1161–1173, DOI:10.1210/jc.2016-2935
Serum testosterone, dihydrotestosterone and estradiol concentrations in older men self-reporting very good health: the healthy man study. Clin Endocrinol (Oxf). 2012 Nov;77(5):755-63. doi: 10.1111/j.1365-2265.2012.04432.x.

Drop in testosterone tied to prostate cancer recurrence

Contact: Diana Quattrone Diana.Quattrone@fccc.edu 215-728-7784 Fox Chase Cancer Center

Fox Chase researchers find that men whose testosterone falls after radiation are more likely to experience a rise in PSA

BOSTON, MA (October 28, 2012)—Men whose testosterone drops following radiation therapy for prostate cancer are more likely to experience a change in PSA levels that signals their cancer has returned, according to new research from Fox Chase Cancer Center. The findings will be presented on October 29 at the American Society for Radiation Oncology’s 54th Annual Meeting.

Specifically, men whose testosterone fell following various forms of radiation therapy were more likely to experience an increase in prostate-specific antigen (PSA)—often the first indication the cancer has recurred.

“The men who had a decrease in testosterone also appear to be the men more likely to see an increase in PSA after treatment,” says study author Jeffrey Martin, MD, resident physician in the Department of Radiation Oncology at Fox Chase.

In theory, doctors may one day be able to use testosterone levels to guide treatment decisions, says Martin. “For men with a decrease in testosterone, doctors might intervene earlier with other medications, or follow their PSA more closely than they would otherwise, to spot recurrences at an earlier time.”

Martin and his colleagues decided to conduct the study because there is limited information regarding testosterone levels after radiation treatment and what it means for prognosis. To investigate whether a decrease in testosterone has any clinical effects, Martin and his colleagues reviewed medical records from nearly 260 men who received radiation therapy for prostate cancer between 2002 and 2008. The men were treated with either brachytherapy, in which doctors insert radioactive seeds in the prostate, or intensity modulated radiation therapy (IMRT), in which an external beam of radiation is directed at the prostate.

The researchers found that testosterone levels tended to decrease following both forms of radiation therapy. And men who experienced a post-radiation drop in testosterone— particularly a significant drop—were more likely to see their PSA levels rise during the follow-up period.

Still, an increase in PSA—known as biochemical failure—was relatively rare, the authors found. “Only 4% of patients with low-risk prostate cancer had biochemical failure at five years,” says Martin.

Even though researchers have seen testosterone decrease following another form of radiation, these latest findings are still somewhat surprising, says Martin, because testosterone is believed to drive prostate cancer. In fact, some patients with advanced forms are prescribed hormone therapy that attempts to knock down testosterone.

“Seeing that a drop in testosterone is tied to recurrence is kind of a surprising result,” says Martin. “We don’t necessarily know what this means yet. I think the relationship between testosterone levels following radiation therapy and prognosis needs more study, and until then it’s premature to say this is something patients should ask their doctors about.”

This was a small study that needs to be validated in a larger group of men before doctors begin basing their predictions of recurrence on patients’ testosterone levels, he cautions. “I think the link between testosterone and PSA needs more study, in a larger set of patients.”

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Martin’s co-authors include Dennis Sopka, Karen Ruth, Mark Buyyounouski, Alexander Kutikov, Mark Sobczak, David Y. T. Chen, and Eric Horwitz from Fox Chase.

Fox Chase Cancer Center, part of the Temple University Health System, is one of the leading cancer research and treatment centers in the United States. Founded in 1904 in Philadelphia as one of the nation’s first cancer hospitals, Fox Chase was also among the first institutions to be designated a National Cancer Institute Comprehensive Cancer Center in 1974. Fox Chase researchers have won the highest awards in their fields, including two Nobel Prizes. Fox Chase physicians are also routinely recognized in national rankings, and the Center’s nursing program has received the Magnet status for excellence three consecutive times. Today, Fox Chase conducts a broad array of nationally competitive basic, translational, and clinical research, with special programs in cancer prevention, detection, survivorship, and community outreach. For more information, visit Fox Chase’s Web site at www.foxchase.org or call 1-888-FOX CHASE or (1-888-369-2427).

Obese Teen Boys Have Up to 50 Percent Less Testosterone than Lean Boys, UB Study Finds

Results send “grim message” that obese teen males may become impotent, infertile adults

Release Date: October 12, 2012

BUFFALO, N.Y. — A study by the University at Buffalo shows for the first time that obese males ages 14 to 20 have up to 50 percent less total testosterone than do normal males of the same age, significantly increasing their potential to be impotent and infertile as adults.

The paper was published online as an accepted article in Clinical Endocrinology.

The authors are the same researchers in the University at Buffalo’s School of Medicine and Biomedical Sciences who first reported in 2004 the presence of low testosterone levels, known as hypogonadism, in obese, type 2 diabetic adult males and confirmed it in 2010 in more than 2,000 obese men, both diabetic and nondiabetic.

“We were surprised to observe a 50 percent reduction in testosterone in this pediatric study because these obese males were young and were not diabetic,” says Paresh Dandona, MD, PhD, SUNY Distinguished Professor in the Department of Medicine, chief of the Division of Endocrinology, Diabetes and Metabolism in the UB medical school and first author on the study. “The implications of our findings are, frankly, horrendous because these boys are potentially impotent and infertile,” says Dandona. “The message is a grim one with massive epidemiological implications.”

The paper is available at http://www.ncbi.nlm.nih.gov/pubmed/22970699.

The small study included 25 obese and 25 lean males and was controlled for age and level of sexual maturity. Concentrations of total and free testosterone and estradiol, an estrogen hormone, were measured in morning fasting blood samples. The results need to be confirmed with a larger number of subjects, Dandona says.

“These findings demonstrate that the effect of obesity is powerful, even in the young, and that lifestyle and nutritional intake starting in childhood have major repercussions throughout all stages of life,” he says.

In addition to the reproductive consequences, the absence or low levels of testosterone that were found also will increase the tendency toward abdominal fat and reduced muscle, Dandona says, leading to insulin resistance, which contributes to diabetes.

“The good news is that we know that testosterone levels do return to normal in obese adult males who undergo gastric bypass surgery,” says Dandona. “It’s possible that levels also will return to normal through weight loss as a result of lifestyle change, although this needs to be confirmed by larger studies.”

The UB researchers now intend to study whether or not weight loss accomplished either through lifestyle changes or through pharmacological intervention will restore testosterone levels in obese teen males.

Co-authors with Dandona are Muniza Mogri, MD, a medical resident in the UB Department of Pediatrics, Sandeep Dhindsa, MD, clinical assistant professor of medicine at UB; Husam Ghanim, PhD, research assistant professor of medicine; and Teresa Quattrin, MD, A. Conger Goodyear Professor and chair of the Department of Pediatrics, housed in Women and Children’s Hospital of Buffalo.

 

[ photograph ]“These findings demonstrate that the effect of obesity is powerful, even in the young,” says UB’s Dandona, who led the research.

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Contact

Ellen Goldbaum

goldbaum@buffalo.edu

716-645-4605 twitter @egoldbaum

Statins Lower Testosterone, Libido

This is a requsted Repost from 2010 link to abstract below:

By Kathleen Doheny WebMD Health News Reviewed byLaura J. Martin, MD

April 16, 2010 — Statin therapy prescribed to lower cholesterol also appears to lower testosterone, according to a new study that evaluated nearly 3,500 men who had erectile dysfunction or ED.

”Current statin therapy is associated with a twofold increased prevalence of hypogonadism,” a condition in which men don’t produce enough testosterone, study author Giovanni Corona, MD, PHD, a researcher at the University of Florence in Italy, tells WebMD.

Although previous studies have produced mixed findings on the possible link between taking cholesterol-lowering drugs and a drop in testosterone, most involved a limited number of patients, with few studies including more than 50 people, Corona says.

“Our study is the first report showing a negative association between statin therapy and testosterone levels in a large series of patients consulting for sexual dysfunction,” he says.

About one of six adults in the U.S. has high cholesterol, according to the CDC. The number of people buying a statin (such as Lipitor or Zocor) rose 88% from 2000 to 2005, from 15.8 million people to 29.7 million, according to the federal Agency for Healthcare Research and Quality.

Statins, Testosterone, and ED: The Study

Corona and colleagues evaluated 3,484 men, average age 51, who visited an outpatient clinic at the University of Florence with complaints of sexual dysfunction between January 2002 and August 2009.

Of that total, 244, or 7%, were being treated with statins for their high cholesterol. Most often the statin was simvastatin (Zocor) or atorvastatin(Lipitor).

The researchers calculated the men’s total testosterone as well as free testosterone, the amount of unbound testosterone in the bloodstream.

When they compared men on statins to those not, the men on statins were twice as likely to have low testosterone, regardless of which of three commonly used thresholds for low testosterone they looked at.

The researchers emphasize they have found a link, not a cause and effect, between statins and lower testosterone. They can’t explain the link with certainty.

One possibility, Corona says, is that low testosterone levels and the need for statin treatment share some common causes.

Some researchers also have looked at the possibility that the statins’ inhibition of cholesterol synthesis may interfere with the production of testosterone, which depends on a supply of cholesterol. The statins may disrupt the body’s feedback mechanism to instruct it to make more testosterone.

”This is huge,” says Irwin Goldstein, MD, director of sexual medicine at Alvarado Hospital in San Diego and editor-in-chief of the Journal of Sexual Medicine.

The study results, he says, demonstrate the need for more study to replicate the finding and figure out the reason for the link.

According to the authors, he says, the best explanation for now is that “statins may disrupt the pituitary feedback to the testicles, telling them to produce testosterone.”

For consumers, he says, the message is for men on statins to pay attention to early warning signs of testosterone deficiency. That includes falling asleep after meals when they did not in the past, noticing poorer athletic performance, having a change from an upbeat mood to a grumpy mood, and experiencing a reduced sex drive, Goldstein says.

If a man suspects testosterone deficiency, Goldstein says he should ask his doctor about checking his testosterone levels.

Statins and Testosterone: Industry Input

In a prepared statement, Sally Beatty, a spokeswoman for Pfizer, the manufacturer of Lipitor, says, “Millions of people have been prescribed Lipitor, which is clinically proven to lower bad cholesterol levels 39%-60% (this is an average effect depending on dose), when diet and exercise aren’t enough.”

The label on Lipitor does warn of the possibility of interference with hormone production, she says. “As described in the Lipitor U.S. prescribing information, statins interfere with cholesterol synthesis and theoretically might blunt adrenal and/or gonadal steroid production.”

But she says, “It is important to note that some other studies and analyses have shown that Lipitor does not have an effect on levels of testosterone or other reproductive steroid hormones.”

Spokesman Lee Davies of Merck and Schering-Plough, which make Zocor andVytorin, had no comment on the study, but says neither of its two statin labels refers to low testosterone.

http://www.ncbi.nlm.nih.gov/pubmed/20141585