Trials in older men with low testosterone levels have shown beneficial effects, such as increased strength, muscle mass, bone mineral density, insulin sensitivity, and libido. However, in elderly men, the treatment effects were short-lived (<6 months).
An observational study of over a 1000 male veterans aged >40 years compared mortality rates between those treated with testosterone and a group of controls with low testosterone. The treatment group showed almost half the rate of mortality, all causes, and lived longer compared to the control group. Other research shows that testosterone replacement lowers HDL levels but only in younger men taking supra-physiological doses (anabolic steroids).
In contrast, a recent research trial with frail, elderly men (>65 years of age) was stopped early due to a greater occurrence of cardiovascular-related events in testosterone treated men.
Conclusion: The Jury is Still Out
Although some testosterone treatment trials report positive results, there is ongoing concern about the risk of incident prostate cancer or prostate cancer mortality because studies have not been large enough or long enough to address this. The report of adverse cardiovascular events associated with treatment highlights the need for further data on the risks and benefits of testosterone treatment in older men, particularly given the large numbers of older men who are prescribed testosterone. And data supporting the libido boost is still out with only some studies reporting benefits. Should your guy be taking testosterone- the jury is still out.