Diabetes is an established risk factor for erectile dysfunction (ED). The pathophysiology of ED in diabetic men is multifactorial, but it mainly involves a vascular disorder related to a reduction of endothelial function. Recently, several studies have correlated ED risk factors with vitamin D deficiency. In this study, we evaluate the relationship between 25-hydroxyvitamin D [25(OH)D] levels, erectile dysfunction, and vascular disease, in type 2 diabetes mellitus men (T2DM). In this observational study, 92 T2DM males (58.83 ± 9.73 years) underwent medical history collection, International Index of Erectile Function (IIEF-5) questionnaire, that allows the identification and grading of DE, physical examination, biochemical/hormonal blood tests, and penile echo-color Doppler ultrasonography. T2DM patients with lower 25(OH)D levels (<25 nmol/l) showed higher penile IMT (p < 0.05), waist circonference (p < 0.05), glucose concentrations (p < 0.05), and lower IIEF-5 score (p < 0.005), testosterone concentrations (p < 0.05), and cavernous peak systolic velocity (PSV) (p < 0.05), compared to patients with 25(OH)D >50 nmol/l. 25(OH)D levels were directly correlated with IIEF-5 (R = 0.39; p = 0.0001), testosterone (R = 0.24; p = 0.02), and PSV (R = 0.24; p = 0.04) and inversely with waist (R = -0.33; p = 0.002), HbA1c (R = -0.22; p = 0.03), triglyceride (R = -0.21; p = 0.06), and penile IMT (R = -0.30; p = 0.009). At multivariate analysis, 25(OH)D deficiency remained an independent predictor of DE. We demonstrate a significant association between 25(OH)D deficiency and erectile dysfunction in T2DM men. This association may be due to the influence of 25(OH)D deficiency on cardiovascular risk factor (glycaemia, HDL cholesterol, and triglycerides), testosterone plasma levels and endothelial dysfunction.
Keywords: Diabetes; Endothelial function; Erectile dysfunction; Testosterone; Vitamin D.