The pathway of partial androgen deficiency of aging male

The well documented age-related decline in serum testosterone (T) in men as the basis of the partial androgen deficiency of aging male (PADAM) syndrome is a typical multifactorial phenomenon. Aging per se can reduce T secretion through several different mechanisms, such as a primary impairment of the testes, the pituitary gland and the neurohypothalamic component, and age-associated changes in peripheral steroid metabolism. Together, these factors define the so called "idiopathic pathway". Generally, the decline in T is exacerbated by many other age-associated clinical conditions that can interfere with T metabolism: these represent the "secondary pathway". Most people experience a PADAM syndrome in which idiopathic and secondary components are simultaneously present. The different multifactorial pathway mechanisms are reviewed in this paper.