Physicians do not have sufficient information from clinical trials to understand the risks associated with the prescription of testosterone in older men, according to a Comment in The Lancet Diabetes & Endocrinology, written by Professor Stephanie Page, of the University of Washington and Harborview Medical Center, Seattle, USA. Large clinical trials to evaluate risks of testosterone treatment are urgently needed, says a new study, "Testosterone, cardiovascular disease, and mortality in men: living in the dark," recently published in the The Lancet Diabetes & Endocrinology - Online First.
While the benefits of testosterone therapy in younger men with a deficiency of the hormone are well established, testosterone is now widely prescribed to older men, particularly in the USA.
Existing studies have produced conflicting findings over whether the prescription of testosterone is associated with increased cardiovascular risk in older men, and ongoing studies are unlikely to adequately address this question, meaning that even if an appropriately powered trial were to start today, reliable safety data are at least a decade away.
According to Professor Page, "In an era when millions of men are using testosterone every day, support is urgently needed from both the public and medical communities to fund an appropriate clinical study to assess the risks and benefits of testosterone treatment in older men. There is a danger that funding and regulatory agencies will overinterpret the evidence from existing and ongoing observational studies, and conclude that larger and longer clinical trials are unnecessary and unwarranted. This conclusion would do men's health a disservice."* (This quote comes direct from author, according to the April 27, 2014 news release, The Lancet Diabetes & Endocrinology: Large clinical trials to evaluate risks of testosterone treatment urgently needed, and cannot be found in text of Comment.)
"Testosterone is a billion dollar industry, probably fuelled partly by direct to consumer advertising and some degree of overprescription," Professor Page adds, according to the April 27, 2014 news release, The Lancet Diabetes & Endocrinology: Large clinical trials to evaluate risks of testosterone treatment urgently needed. "Physicians need to discuss with their patients that we simply do not fully understand the risks associated with testosterone use in older men, and use conservative treatment guidelines – such as those provided by the Endocrine Society – to guide therapeutic decisions." (This quote comes direct from author, according to the April 27, 2014 news release, The Lancet Diabetes & Endocrinology: Large clinical trials to evaluate risks of testosterone treatment urgently needed, and cannot be found in text of Comment.)
Two-faced testosterone can make you nasty or nice
Research suggests that testosterone has a key role in social interactions. You also may be interested in another paper, "Prejudice and truth about the effect of testosterone on human bargaining behavior," by Eisenegger et al., published January 21, 2010 in the journal Nature.
Is aggression always the best response to a challenge? Testosterone may not necessarily cause aggression but behavior can drive testosterone secretion. In an evaluation for Faculty of 1000, Robert Sapolsky highlights a study published in Nature which assessed how testosterone affects human behavior in a 'pro-social' situation – an environment where it is beneficial for a person to help someone else. Robert Sapolsky, according to the March 8, 2010 news release, "Two-faced testosterone can make you nasty or nice," is a Faculty Member for F1000 Biology, is Professor of Neurology & Neurological Sciences Stanford School of Medicine.
In an 'Ultimatum Game', a 'proposer' is given power to decide how a sum of money is divided between him/herself and another player, 'the decider'. The decider can either accept the offer, and possibly receive less than a fair share, or reject it,in which case both players get nothing. The participants in the game were all women.
Women who were given testosterone unknowingly made fairer offers (a pro-social decision) than women who received a placebo
Interestingly, women who believed that testosterone has anti-social, aggression-causing effects and who thought they'd received testosterone made offers that were less fair, even when they had received a placebo. When given to the subject in a blind trial, testosterone can encourage pro-social as well as anti-social behavior. However, as the authors note, "biology seems to exert less control over human behavior [than in other animals]," since awareness of having received testosterone drastically altered behavior.
So, not only can our own behavior be confounded by our prejudices but the effects of testosterone may be far more complex than previously thought. As Sapolsky says, according to the news release, "Despite the seeming power of the proposer, the decider ultimately has the most power, and the proposer seriously loses status if the decider rejects their offer."
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