Objective: In the 5-10% of diabetic men with type 1 diabetes, erectile dysfunction (ED) may be a particularly common and unwanted complication. This is the first study focusing exclusively on the effects of sildenafil in men with type 1 diabetes and ED.
Research design and methods: A total of 188 patients were entered into a double-blind, placebo-controlled, parallel-group, flexible-dose study and were randomized to receive sildenafil (25-100 mg; n = 95) or placebo (n = 93) for 12 weeks. Efficacy was evaluated using questions three (Q3; achieving an erection) and four (Q4; maintaining an erection) from the International Index of Erectile Function (IIEF), a global efficacy question (GEQ; "Did treatment improve your erections?"), and a patient event log of sexual activity.
Results: Improvements in mean scores from baseline to end-of-treatment for IIEF Q3 (35.7 vs. 19.9%) and Q4 (68.4 vs. 26.5%) were significant in patients receiving sildenafil compared with those receiving placebo (P = 0.0001). Moreover, the percent of improved erections (GEQ, 66.6 vs. 28.6%) and successful intercourse attempts (63 vs. 33%) was significantly increased with sildenafil compared with placebo. Improvements in sexual function were seen irrespective of the degree of ED severity. Adverse events were generally mild to moderate in severity, with headache (20 vs. 8%), flushing (18 vs. 3%), and dyspepsia (8 vs. 1%) reported more often in the sildenafil than in placebo-treated patients.
Conclusions: Treatment with sildenafil for ED was effective, resulting in an increased percentage of successful attempts at intercourse, and was well tolerated among men with type 1 diabetes.