Diabetes-related impotence and its treatment in the middle-aged and elderly: Part I.

Diabetes-related impotence is commonly noted within 10 years of the onset of diabetes. It is frequently due to microangiopathy and is associated with symptomatic neuropathy. Careful history-taking, physical examination, laboratory tests, and frequently, sophisticated diagnostic tests are indicated in the evaluation of these patients. Nocturnal penile tumescence and rigidity testing has become the gold standard of noninvasive evaluation.