Testosterone and the metabolic syndrome

Abstract 

There is convincing evidence that abdominal obesity, a key factor in the metabolic syndrome, is associated with low testosterone levels and, conversely, low levels of testosterone are a risk factor for development of the metabolic syndrome, thus producing a vicious circle. The mechanisms by which the metabolic syndrome induces hypogonadism are increasingly being elucidated. It is now clear that insulin resistance decreases Leydig cell responsiveness to stimulation with human chorionic gonadotropin.

Androgen depletion in men with prostate cancer has demonstrated an impressive increase in insulin resistance and the risk of developing type 2 diabetes mellitus. Androgens have direct (membrane) effects on pancreatic β-cells thus stimulating insulin production.

The relationship between circulating testosterone levels and the metabolic syndrome has been demonstrated in elderly men, but, paradoxically, there is a lack of effect of testosterone insulin sensitivity or glucose tolerance in healthy young men.

Interventions with testosterone in men with the metabolic syndrome lead to improvements of body composition (decreasing fat mass and increasing lean body mass) and improve insulin sensitivity.

Keywords: Testosterone levels, Metabolic syndrome, Hypogonadism