Addition of metformin to sildenafil treatment for erectile dysfunction in eugonadal nondiabetic men with insulin resistance. A prospective, randomized, double-blind pilot study.

Erection depends largely on the release of nitric oxide (NO) by vascular endothelial cells. Insulin resistance (IR) is a metabolic abnormality that produces endothelial dysfunction characterized by decreased synthesis and release of NO. The aim of this paper is to evaluate the effect of treatment with metformin on the response to sildenafil in patients with erectile dysfunction (ED) and IR enrolled in a prospective, randomized, controlled, double-blind placebo study.

Erectile dysfunction, obesity, insulin resistance, and their relationship with testosterone levels in eugonadal patients in an andrology clinic setting.

Erectile dysfunction (ED) is associated with metabolic and endocrine diseases including obesity, metabolic syndrome (MS), and type 2 diabetes mellitus (DM2). Insulin resistance (IR), present in patients with obesity, MS, and DM2, causes disturbances in the signaling pathways required for nitric oxide production, with subsequent endothelial dysfunction. In addition, IR appears to alter testosterone production.