Autonomic neuropathy and sexual impotence in diabetic patients: analysis of cardiovascular reflexes

Four cardiovascular tests exploring autonomic nervous function (Deep Breathing, 30:15 ratio, Lying to Standing, Hand Grip) have been performed in 38 diabetic patients with erectile failure (mean age 53.2 years, range 34.5-60.5) and in 35 diabetic subjects without sexual dysfunctions (mean age 52.8 years, range 45-60.5). In our study Deep Breathing test was abnormal in 21 patients with erectile failure (55.3%) and in 9 patients without sexual dysfunction (25.7%) (P less than 0.05). Seven patients with sexual impotence (18.4%) and 2 subjects without sexual dysfunction (5.7%) showed abnormal results of 30:15 ratio test. The Lying to Standing test was not abnormal both in impotent and in non impotent subjects, while the Hand Grip test was abnormal in 7 patients with impotence (18.4%) and in 8 patients without sexual dysfunction (22.9%). Results obtained from Deep Breathing test were significantly lower (P less than 0.01) in impotent (10.25 +/- 6.10 beats/min) than in non impotent patients (14.63 +/- 6.85 beats/min). Lower 30:15 ratios were also found in patients with erectile failure (1.09 +/- 0.10 vs 1.12 +/- 0.09). The tests exploring the sympathetic function did not show any difference between the two groups of patients. The present study confirms the major role of parasympathetic impairment in the pathogenesis of sexual dysfunctions in diabetic men. Cardiovascular tests can be a first-step diagnostic tool in the assessment of diabetic impotence.