Testosterone Replacement Therapy in Men: Effects on Fertility and Health

Abstract

Epidemiological studies clearly demonstrated a gradual decline in serum testosterone levels as men age, resulting in a cluster of clinical presentations such as decrease in energy, libido, sexual function, bone mineral density, muscle mass, and mood. This condition, termed late-onset hypogonadism (LOH) but also known as testosterone deficiency syndrome, partial androgen deficiency in aging men, or “andropause” in laymen’s term, can be managed by testosterone replacement therapy (TRT). In addition to improvement in many signs and symptoms of LOH, a wealth of current literature suggests that TRT may also have other health benefits such as increase in muscle mass, reduction in fat mass, improvement in glucose metabolic and lipid profiles, and voiding function. Furthermore, latest observational and interventional studies demonstrated that the risks of severe adverse events with TRT such as cardiovascular events and prostate cancer are much lower than previously expected. Among the various side effects of TRT, suppression of spermatogenesis leading to infertility is not frequently addressed, partly because most men who develop LOH requiring TRT are presumably past the traditional reproductive age. However, as seen in most societies, men have been postponing paternity until later age when they are at risk to have LOH. The impact of TRT on male reproductive health is thus a relevant and timely health issue. Clinicians managing men’s health should be aware of the potential health risks, in addition to the efficacy, of TRT when counseling men presenting with LOH.