Erectile dysfunction occurs 10 to 15 years earlier in men with diabetes than in men in the general population. Erectile dysfunction in men with diabetes tends to be multifactorial. Romeo and colleagues examined the relationship between glycemic control and erectile dysfunction in men with type 2 diabetes (formerly known as non–insulin-dependent diabetes).

The 78 men in the study ranged from 38 to 82 years of age (mean age: 62 years). Nearly one half (49 percent) required insulin for the treatment of type 2 diabetes. Glycoslylated hemoglobin (HbA_1c) concentration ranged from 5.2 to 15.6 percent (mean: 8.1 percent). To evaluate erectile function, the study participants completed five questions of the International Index of Erectile Function. A score of erectile function was derived from the sum of the questions (maximum score: 25). Information about disease duration, diabetic complications and treatment regimens was also obtained for each participant.

Data revealed that the lower the HbA_1c concentration, the better the mean erectile function score. In the 10 patients with an HbA_1c concentration of 6.0 percent or less, the mean erectile function score was 21.5. In contrast, in the 20 patients with an HbA_1c of 9.0 percent or greater, the mean erectile function score was 13.4. In the 17 patients with an HbA_1c of 6.1 to 7.0 percent, the mean erectile function score was 18.4. In the 15 patients with an HbA_1c concentration of 7.1 to 8.0 percent, the mean erectile function score was 16.3, and in the 16 patients with an HbA_1c concentration of 8.1 to 9.0 percent, the mean erectile function score was 16.0. The correlation between HbA_1c and erectile function score was true even after controlling for the presence or absence of peripheral neuropathy.

The authors conclude that erectile function correlates with HbA_1c levels in men with type 2 diabetes. The findings of this study provide another reason to encourage patients to strive for good glycemic control.

editor's note: Tight glycemic control in diabetes is now emphasized because more and more research has documented that tight control can delay and reduce the adverse effects of diabetes on multiple systems. In this study, Romeo and colleagues have documented another advantage of tight control. That good control of diabetes can prevent impaired sexual function is another benefit physicians can tell patients about when they are explaining the importance of blood glucose levels.—k.e.m.