Diabetes and ED

Association of Erectile Dysfunction with Diabetes Mellitus

Erectile dysfunction (ED) is a significant medical problem for a large number of men with diabetes mellitus. The prevalence of ED is three times higher in diabetic men (28% versus 9.6%), occurs at an early age and increases with disease duration, being approximately 15% at age 30 rising to 55% at 60 years. ED increases with poor control of diabetes and complications of diabetes, such as vascular and nerve diseases. The prevalence of heart artery blockages (20%) and peripheral artery blockages (5%) in men with diabetes is far higher than in the general population, and both are common risk factors for ED as well.

Diabetes mellitus may cause ED through a number of changes affecting psychological function, central and peripheral nervous system function, male hormone (androgen) function, blood vessel lining (endothelial cell) function and smooth muscle function (necessary for erection). The problem may be due to one or a combination of these possible factors.

This information sheet examines the relationship between diabetes and penile functions such as penile blood flow function, penile nerve function and penile smooth muscle function.

Penile erection depends upon sexual stimulation greatly increasing blood flow into the penis, relaxation of the penile arteries and relaxation of penile smooth muscle. Disturbances of these relaxation mechanisms can be diagnosed by special tests.

Artery blockages are 40 times more prevalent in men with diabetes compared to non-diabetics and are more commonly associated with ED. Men with diabetes show a reduction in the number and rigidity of nighttime erections experienced during sleep. Using an electron microscope, investigators have shown that erection tissue is permanently changed in diabetic men compared with controls, including less smooth muscle content, more scar (connective tissue) deposition and fewer blood vessel lining (endothelial) cells. In comparison to control erectile tissue from potent men, erectile tissue specimen from diabetic men showed impaired ability to relax smooth muscle. This abnormality leads to loss of blood from the erection chambers leading to poor ability to maintain the erection. This is called a “venous leak”.

Normal blood vessel lining (endothelial) cells form a biologic layer that regulates the flow of nutrients and the action of various biologic molecules circulating in the blood into the surrounding smooth muscle surrounding the blood vessel. Normal blood vessel lining (endothelial) cells also secrete various molecules that regulate blood flow by changing the tone of the blood vessel smooth muscle.

Abnormal blood vessel lining (endothelial) cells in diabetics occur in approximately 50% of men with diabetes. Elevated blood sugar levels cause injury to the blood vessel lining (endothelial) cells. This has an adverse effect on repair mechanisms, enhancing the progressive damage to the lining cells and ultimately lead to arterial blockage (atherosclerosis). Insulin is thought to enhance endothelial cell function.

Most patients with ED can benefit from treatment today. Treatment options include sexual counseling, drug treatment and mechanical or surgical interventions. However, diabetic men with erectile dysfunction tend to be less responsive to treatment, perhaps because the cause of diabetes-associated erectile dysfunction is likely to be multi-factorial.

Although sex therapy is a wonderful tool for couples, men with diabetes mellitus normally have vascular damage and therefore require medical intervention. Drug treatment comes in different forms. The easiest treatment is by oral phosphodiesterase type 5 (PDE-5) inhibitor. Currently the only PDE-5 inhibitor available in the US is Viagra, which tends to be less effective in the diabetic than in the non-diabetic ED patient. In the future Vardenafil, which has shown very good efficacy and tolerability in the population with diabetes mellitus, and Tadalafil will be available by prescription.

For those patients who do not respond to oral therapy, drugs can be injected directly into the penis. This is a different type of drug which is used which works in a different way. If you take Viagra you still need sexual stimulation. Intracavernosal injection therapy requires no sexual stimulation. We are able to work with you through a series of appointments to find the best mixture to give you an injection and teach you (or your partner) how to inject yourself in order to have sexual relations when you so desire.

If intracavernosal injection therapy does not work for you our patients have success with insertion of a penile prosthesis. Unlike early prostheses that left you with a permanent erection, modern prostheses allow your penis to look flaccid (soft), and then have an erection on demand by activating the internal pump.

If you have a penis, we can help you achieve an erection. There is no reason to suffer, or assume that because you have diabetes mellitus you can no longer have a satisfying sex life.

Primary teaching affiliate
of BU School of Medicine