Hypogonadism in Metabolic Syndrome: Cause or Consequence? Lesson from Genetic Hypogonadism and Disorders of Gender Identity

Hypogonadism is frequently associated with metabolic syndrome and testosterone levels correlate with parameters which are part of the cluster defining the syndrome itself. Different studies suggest a positive role of testosterone replacement therapy, but different aspects (including the definition of hypogonadism, especially in aging male, and the modality of treatment) still require confirmation. A model to explore the role of testosterone in influencing the beginning and course of the syndrome is early hypogonadism, due to genetic causes (both primary or secondary hypogonadism); moreover, few data are reported in transsexuals, despite the debate on biological bases of gender indentity, and the influence of pharmacological treatment before and after surgical sex reversal. We present here a review of literature and some paradigmatic cases, that seem to reinforce the concept of hypogonadism as a causative factor of metabolic syndrome.