Erectile function and penile blood pressure in diabetes mellitus.

Thirty-seven diabetic men selected to exclude the confounding effects of other medical illnesses and nondiabetic medications and 53 healthy controls underwent extensive psychosexual and medical evaluations and penile blood pressure assessments by ultrasonic Doppler measurement and mercury strain-gauge plethysmography. There was a significant negative correlation between age and the penile-brachial index (PBI) in the diabetic but not in the control group. The impotent diabetic group had significantly lower PBI than nondysfunctional diabetic and healthy control subjects. Diabetic type, complications, and adequacy of metabolic control were not statistically related to PBI. Although the PBI may not have diagnostic utility for individual patients, it may provide a valuable noninvasive physiologic measure of penile vascular changes in studies on the aged and the medically ill. The processes that mediate the interaction of diabetes and aging on penile blood pressure and erectile capacity deserve further investigation.