Beware – too much testosterone could kill you!


A new study found that men who live the longest are those who have medium testosterone levels. High or low testosterone levels are linked to reduced mortality. Testosterone is a key male sex hormone involved in maintaining sex drive, sperm production and bone health. Physicians have long known that low testosterone levels can signal health problems, but the new study found men may not fare better when levels of the hormone rise too high.

‘Older men who had testosterone in the middle range survived longer than their counterparts who had either low or high levels of the hormone,’ the study’s lead author, Bu Beng Yeap, MBBS, FRACP, PhD, of the University of Western Australia, based in Fremantle Hospital, Western Australia, said. ‘When the body metabolizes testosterone, it produces dihydrotestosterone (DHT), which is tied to a lower risk of dying from ischemic heart disease. Having the right amount of testosterone and higher levels of DHT might indicate these men are in better health overall, or it could help them maintain good health as they grow older,’ the researcher said.

The population-based cohort study analyzed the mortality rate in a group of 3,690 community-dwelling men between the ages of 70 to 89 in Perth, Western Australia. Participants’ testosterone and DHT levels were measured between 2001 and 2004. Researchers analyzed the group’s survival rate as of December 2010.

Researchers divided the men into four groups based on their testosterone levels. Men with the lowest testosterone levels had the highest cumulative mortality rate, followed by the men with the highest testosterone levels. Men with circulating testosterone levels in the 9.8 to 15.8 nmol/L range tended to live longer. ‘Sex hormones are an important predictor of mortality in older men, but we haven’t determined if treatments to change testosterone and DHT levels can alter these outcomes,’ Yeap said.

The research is set to be published in The Endocrine Society’s Journal of Clinical Endocrinology and Metabolism.

What we’ve learned about testosterone till now?

We don’t get enough testosterone

More than 25 percent of urban Indian males have low testosterone hormones due to unhealthy lifestyles. However, lack of awareness means that many patients go undiagnosed, doctors say. ’Male Hypogonadism’ affects 26.1 percent of the working population of Indian men and is caused by unhealthy lifestyle, including smoking, consuming alcohol and junk food, high stress levels etc. The hormone plays a key role in masculine growth and development during puberty.

 According to doctors, symptoms include decreased libido, impaired erectile function, muscle weakness, fatigue and depression. ‘It is an established clinical condition in medicine and in India the numbers are rising drastically over the years. However, many patients with this disorder go undiagnosed,’ Ajit Saxena, senior consultant urologist and andrologist, Apollo Indraprastha Hospitals, told IANS. ‘There is a clear need to increase the awareness of hypogonadism with the rising evidence suggesting a rise in the prevalence of the disorder in working population of Indian men,’ he added. Sadly, not many general physicians are aware of this disorder.

Testosterone keeps depression at bay

Testosterone, the primary male sex hormone, also keeps depression at bay. Now scientists have figured out how. Nicole Carrier and Mohamed Kabbaj of the Florida State University have found that a specific pathway in the brain’s hippocampus, involved in memory formation and stress response regulation, plays a major role in mediating the testosterone’s effects.  Carrier and Kabbaj performed multiple experiments in neutered adult male rats. The rats developed depressive behaviour that was reversed with testosterone replacement, the journal Biological Psychiatry reports. They also ‘identified a molecular pathway called MAPK/ERK2 in the hippocampus that plays a major role in mediating the protective effects of testosterone’, said Kabbaj, according to a Florida statement.

It could be used as a male contraceptive

A hormonal gel combo applied daily to the skin showed promise as a male contraceptive by reducing sperm production, say US scientists. About 89 percent of men using the new combo of skin gels enriched with testosterone and a new synthetic progestin called Nestorone, reported very low sperm counts. 

‘This is the first time that testosterone and Nestorone have been applied to the skin together to deliver adequate amounts of hormones that suppress sperm production,’ said principal investigator Christine Wang, professor at the University of California’s Los Angeles Biomedical Research Institute.

‘Men can use transdermal (skin) gels at home – unlike the usual injections and implants, which must be given in a health care provider’s office,’ added Wang, according to a California statement. Prior studies of male contraceptives that combined testosterone and progestin used progestin pills, implants or shots, according to Wang.

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