ABSTRACT
The causes of progressive hypoandrogenemia (low blood levels of androgens) in the aging male arise at multiple levels in the gonadal axis. Pathophysiological mechanisms embody a threefold composite of the following:
• Diminished hypothalamic gonadotropin-releasing hormone (GnRH) release
• Impaired feedforward drive by pituitary luteinizing hormone (LH) of testicular androgen biosynthesis
• Altered sex steroid-dependent feedback control of GnRH/LH secretion
The foregoing tripartite perspective is reviewed here.
