New Horizons in Testosterone and the Ageing Male

Tomás Ahern; Frederick C. W. Wu


Age Ageing. 2015;44(2):188-195. 

In This Article


The fall in testosterone levels with age appears to be a real phenomenon. The prevalence of LOH, among men aged 40–70, is ~2%. Declining testicular function and hypothalamic dysregulation appear to be the mechanisms explaining the fall in testosterone levels with age. The increased prevalence of obesity and chronic illness in ageing men both cause a large drop in testosterone levels through mechanisms independent to, and of greater magnitude to, those from ageing.

Age-related hypogonadism appears to be different to other 'classical' causes of hypogonadism. Testosterone levels are not unequivocally low and associated symptoms are non-specific. In frail older men with low testosterone levels, testosterone therapy appears to improve QOL and physical function. In less frail men, however, effects of testosterone therapy in the ageing male are small and/or inconsistent for QOL, physical function, bone health and metabolic health.

These issues, together with the risks of testosterone therapy, make the decision to initiate testosterone therapy in older symptomatic men, a complex and challenging one generating the imperative to establish a formal diagnosis of hypogonadism, usually without identifiable underlying pathology of the HPG axis. The Testosterone Trials in which 788 men aged over 65 with a total testosterone concentration <9.4 nmol/l will receive transdermal testosterone, or placebo, for 1 year will provide important information on the short-term efficacy of testosterone.[46] There remains an urgent need for RCTs with sufficient size, duration and power to determine specific benefits and risks of testosterone therapy in older men. In a broader context, low testosterone levels should be regarded as a biomarker of obesity and chronic illness (overt or occult) thereby proffering an important portal to improving men's health.