Abstract
Nocturnal penile tumescence (NPT) during sleep was measured in 28 impotent diabetics to differentiate the causes of the impotence. The subjects had no severe complications and had not taken drugs that induce impotence. Before the measurement of NPT, all drugs that could interfere with erection during the REM period had been cleared from the body.
Twelve patients showed the normal pattern of NPT, which was more than 20% increase of maximal NPT in penile circumference at the tip or base, and the remaining 16 patients showed abnormal NPT.
There were no significant differences in age, duration of diabetes, duration of impotence, libA, body weight and the methods of treatment of diabetes between the normal NPT and abnormal NPT groups. However, the Achilles tendon reflex and nerve conduction velocity of the leg were significantly decreased in the abnormal NPT patients. Among these patients, orthostatic hypotension and a tendency to depression were more frequent than in the group with normal NPT.
In conclusion about 40% of the diabetic patients who complained of impotence were functional and they had less peripheral neuropathy, orthostatic hypotension and depressive tendencies than those with abnormal NPT. We experienced three patients whose impotence improved after we showed and explained to them the results of their NPT measurements.
