Erectile and endothelial dysfunction in Type II diabetes: a possible link

Aims/hypothesis. The aim of this study was to evaluate the relation between erectile dysfunction and endothelial functions, coagulation activation, peripheral and autonomic neuropathy in men with Type II (non-insulin-dependent) diabetes mellitus. Methods. We studied 30 Type II diabetic patients with symptomatic erectile dysfunction and 30 potent diabetic patients matched for age and disease. Endothelial functions were assessed with the L-arginine test, plasma thrombomodulin and cell adhesion molecules circulating concentrations. Haemostasis was evaluated with markers of thrombin activation and fibrinolysis. Quantitative sensory testing (vibratory, warming, and heat-pain thresholds), cardiovascular reflex tests and 24-h blood pressure monitoring were used to assess peripheral or autonomic neuropathy. Results. Mean erectile score and HbA(1c) were 10.5 +/- 5.8 and 8.3 +/- 1.6% in patients with erectile dysfunction, and 24.0 +/- 0.7 and 6.8 +/- 1.4 % in those without erectile dysfunction, respectively (p < 0.001); there was a significant relation between HbA(1c) and erectile function score in patients with erectile dysfunction (r=-0.45, p=0.02). The decrease in blood pressure and platelet aggregation in response to L-arginine was lower (p < 0.05-0.02) in patients with erectile dysfunction, whereas soluble thrombomodulin, P-selectin and intercellular cell ahhesion molecule-1 concentrations were higher (p < 0.05-0.02). Indices of coagulation activation (F1 + 2 and D-dimers) and reduced fibrinolysis (PAI-1) were also found to be higher in erectile dysfunction patients. Heat-pain and warm perception thresholds, as well as cardiovascular reflex tests, were most commonly abnormal in patients with erectile dysfunction (p < 0.05). In multivariate analysis, HbA(1c), MBP response to L-arginine, P-selectin, indices of coagulation, and quantitative sensory testing were independent predictors of erectile function score. Conclusion/interpretation. Erectile dysfunction in diabetic men correlates with endothelial dysfunction. A reduced nitric oxide activity might provide a unifying explanation.