A series of clinical trials have produced results indicating that testosterone replacement therapy could alleviate some of the unwanted health-related problems caused by the natural decline of testosterone with age. Further studies are needed to confirm these findings and to explore the long-term effects of testosterone replacement therapy.
The primary male hormone, testosterone, exhibits a gradual decline in levels with increasing age in males. Given its broad range of effects within the body, it is no surprise that this decrease leads to a range of adverse outcomes. This clinical scenario can be likened to the deficiency of estrogen in post-menopausal women, for which hormone replacement therapy is routinely used. It is, therefore, reasonable to question why, similarly, testosterone is not simply replaced in men with low levels of the hormone.
In 2003, a series of 7 clinical trials, known as the T-trials, were performed in order to look further into the benefits of testosterone therapy. This was mainly due to the lack of evidence at the time supporting the therapeutic use of testosterone. Some of the areas of interest included sexual function, physical performance, vigor, bone mineral density, and anemia. Research was also carried out into the effects of testosterone on cardiovascular health. It is important to note that these trials only evaluated the short-term effects of testosterone therapy.
Results from the trials were reported in The Journal of the American Medical Association. With regards to bone, testosterone replacement produced an improvement in density similar to that seen in patients taking medication approved for treatment of osteoporosis. Improvements were also found in patients with both explained and unexplained anemia, as expected given the known effect of testosterone on increasing red blood cell count. This finding is particularly beneficial as there is no current treatment for unexplained anemia, hence testosterone therapy could be a viable option, in addition to potentially providing treatment to those with explained anemia who have not benefited from routine treatment.
Another set of notable findings in a separate study report that testosterone replacement was found to reduce the incidence of cardiovascular events in testosterone deficient males. This is contrary to results from previous studies that highlight a possible increase in cardiovascular events with higher levels of testosterone. Whilst this is a promising discovery, this set of findings in particular call for more in-depth research as there are a number of safety issues that were not explored. It is also important to note the participants in this study were predominantly young, healthy males so results may not reflect outcomes that would be observed in an older population.
It is clear that testosterone therapy may have a significant list of benefits in older men deficient in the hormone, however, further studies are needed to gain definitive supporting evidence whilst also obtaining much-needed data relating to the long-term effects of this treatment option.
Written By: Saran Amin, MPharm