Andropause: Clinical Implications of the Decline in Serum Testosterone Levels With Aging in Men

T is now well accepted that serum testosterone (T) levels decline progressively with aging in men (1‐5). This decline is associated with alterations in body composition; diminished energy, muscle strength, and physical function; reduced sexual function; depressed mood; and decreased cognitive function. Similar changes occur in young men with androgen deficiency and are improved with T replacement therapy. However, the physiological and clinical significance of the aging-associated decline in serum T levels in men is unclear, particularly because T levels may remain within the normal range for young men. From a practical clinical standpoint, it is most appropriate to define “andropause” as an age-related decline in serum T levels in older men to below the normal range in young men that is associated with a clinical syndrome (i.e., symptoms and signs) consistent with androgen deficiency. The decline in T levels is a consequence both of aging per se and age-associated comorbid illnesses and medications that are used to treat them