Men’s testosterone levels remain pretty steady until age 70. After that, production of the male sex hormone starts to decline, new research indicates.
This begs the question: Is testosterone loss among seniors really a function of the normal aging process? Or might it reflect other health issues that often confront men as they get older?
Both may be true, say investigators, with obesity, high blood pressure, diabetes and even marital status among the factors that appear to drive testosterone levels down, in conjunction with age.
When testosterone does fall, the result may be increased weakness and fatigue, diminished sexual performance, loss of muscle mass, and a higher risk for diabetes and dementia.
While you can’t do anything about your age, the findings suggest some positive lifestyle changes might help preserve your masculinity.
Study author Bu Yeap said that after 70 the pituitary gland at the base of the brain actually sends out signals to increase, not decrease, testosterone production.
To find out what might be short-circuiting that signal, the study team analyzed 11 studies from Australia, Europe and North America, involving some 25,000 men in total, said Yeap, an endocrinologist and medical school professor at the University of Western Australia.
All the studies were conducted prior to 2020. In each, men’s testosterone levels were repeatedly measured over time using a technique called mass spectrometry.
Collectively, the data revealed that “on average, testosterone levels are lower in older men compared to younger men,” noted Yeap, who is also a past-president of the Endocrine Society of Australia.
But the analysis also indicated that concentrations of another testosterone-increasing hormone — LH (luteinizing hormone) — goes up after 70. And Yeap noted that testosterone declines directly attributed to age were deemed to be relatively “modest.”
Meanwhile, a wide range of other factors were found to contribute to a post-70 decline in testosterone. These included heart disease, smoking history, cancer, diabetes, high blood pressure, excess body weight, reduced activity and even marriage.
In particular, being overweight or obese was found to have “a much more prominent association” with lower testosterone levels, relative to older age alone, he added.
Men over 70 who took drugs to control high cholesterol levels were also found to have slightly lower testosterone levels, the analysis indicated.
As for marriage and long-term relationships, both were pegged as having a testosterone-dampening impact among seniors.
“A possible explanation,” Yeap suggested, “could be that married men with families might be more stressed, and therefore have lower testosterone levels. But our study wasn’t designed to look further into this result.”
He said the main message is that a range of sociodemographic, lifestyle and medical factors influence testosterone levels in men.
“These need to be considered when doctors interpret testosterone results from individual men, as testosterone levels might be lower than expected in the presence of these conditions, rather than being always due to an (age-related) problem with the testes,” Yeap added.
Dr. Robert Eckel is past president of the American Heart Association, and past president of medicine and science with the American Diabetes Association.
After reviewing the findings, he stressed that the continuously emerging picture of testosterone production dynamics “seems to be more complicated all the time.”
But while noting how “difficult” it is to get a precise handle on the various reasons for falling testosterone, Eckel pointed to two potentially critical factors: LH levels and levels of a key protein (sex hormone-binding globulin, or SHBG) tasked with transporting testosterone throughout the body.
A drop in either — whether due to health complications or the march of time — could lead to a dip in testosterone levels and/or availability, Eckel said.
Since lower testosterone can undermine quality of life, what should a concerned man do?
Eckel and Yeap urged older patients to consult their doctor in order to determine whether or not testosterone supplementation therapy might be appropriate or helpful.
“Testosterone treatment should only be given if there is a clear medical reason,” stressed Yeap, “and always under medical supervision.”
The findings were published online Aug. 28 in the Annals of Internal Medicine.
Harvard Medical School has more on testosterone and aging.
SOURCES: Bu B. Yeap, MBBS, PhD, professor, Medical School, University of Western Australia, Crawley, Australia, and endocrinologist, Fiona Stanley Hospital, Perth, Western Australia, and past-president, Endocrine Society of Australia; Robert H. Eckel, MD, past president, American Heart Association and past president of medicine and science, American Diabetes Association, and professor of medicine, emeritus, division of endocrinology, metabolism & diabetes, and division of cardiology, University of Colorado Anschutz Medical Campus; Annals of Internal Medicine, Aug. 28, 2023, online
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