Diabetic secondary impotence: neuropathic factor as measured by peripheral motor nerve conduction.

Fifty-six type II diabetic males (mean age 52) were studied. Nineteen (33.9%) were diagnosed as having secondary impotence (SI); there was no correlation with age, diabetic control, and the use of insulin versus oral antidiabetic agents. Positive correlation was found between slow (less than 42 M/sec) motor nerve conduction velocity (MNCV) and SI at p less than 0.02, amounting to 58 per cent of the 19 cases. SI did not correlate with a standard list of peripheral neuropathic symptoms alone in the absence of slow MNCV. Correlation with SI was greatest when slow MNCV coexisted with neuropathic symptoms (p less than 0.04). MNCV testing may improve diagnosis and cost-effectiveness in assessing diabetic men with impotence.