Diabetes and Men's Sexual Function
Erectile dysfunction is treated through a variety of approaches
Erectile dysfunction (ED), the inability to sustain an erection sufficient for intercourse, is a common complication of both Type 1 and Type 2 diabetes in men. Affecting 35 percent to 75 percent of men with diabetes, particularly those over 50 years of age, ED usually appears gradually, beginning with less rigid and fewer erections before developing into a chronic inability to achieve an erection. If ED is a problem for you, alert your doctor. A number of treatments can help you achieve erections.
What causes ED?
The stimulus for an erection begins when impulses from the brain are sent through the spinal cord to the penis. These impulses cause blood vessels in the corpora cavernosa, two rod-shaped bundles of spongy muscle that run along each side of the penis, to relax and fill with blood. As they fill, the corpora cavernosa expand and press against the veins that would normally drain blood from the penis. Thus engorged, the penis enlarges and stiffens. Failure to achieve an erection may be due to impairment at any stage in this sequence of events.
ED can result from either a psychological or physical problem. Overall, psychological problems account for 10 percent to 20 percent of ED cases. General stress associated with diabetes can have a psychological impact on sexual function. Moreover, just the knowledge that people with diabetes are at increased risk, or the fear of erectile failure, may precipitate ED in some men.
Physical problems that cause ED include vascular, neurological and hormonal abnormalities, as well as the use of certain medications. The increased incidence of vascular disease and neuropathy are specific physical causes of ED in men with diabetes. Vascular disease can lead to impotence by narrowing or blocking arteries, which limits blood flow to the penis; damage to the nerves raises the risk of ED by interfering with the signals that affect the muscle tissue within the penis and widen the blood vessels. In addition, some of the nonspecific effects of diabetes are no doubt responsible for the increased prevalence of ED. High blood sugar, for example, can leave a person feeling generally tired and run-down.
Identifying the cause of ED begins with a medical and sexual history, as well as a physical exam. The ability of men to have erections in their sleep (which doctors can test for by placing a small band around the penis while you sleep) but not during intercourse suggests that psychological factors contribute to their impotence. Occasionally, low testosterone or elevated prolactin levels are responsible for ED; these hormonal problems can be detected with blood tests and treated. Prescription medications, including some antihypertensive drugs (a particular risk for men with diabetes, since they are often treated concurrently for hypertension), antidepressants, antianxiety drugs and histamine-receptor blockers (used to treat peptic ulcers) can also cause ED. Their effects should be evaluated, and, if they appear to be the cause, other drugs can be tried. Special tests can identify abnormal arteries or nerve damage, but these tests are not essential before trying measures to improve ED.
ED may be treated through one or more of the following approaches:
Testosterone
ED caused by low testosterone levels can be overcome with administration of testosterone by injection or through a patch on the skin.
Blood glucose control
Tight blood glucose control may help prevent ED. Although neither study tested ED itself, results from the Diabetes Control and Complications Trial (DCCT) revealed that people with Type 1 diabetes who control their blood glucose levels reduce their risk of diabetic neuropathy by 60 percent, and results from the United Kingdom Prospective Diabetes Study (UKPDS) found similar benefits from tight blood glucose control in Type 2 diabetes.
Lifestyle changes
Because smoking and excessive alcohol use both raise the risk for ED, eliminating them may help alleviate ED.
Psychological treatments
Stress, depression and anxiety should all be assessed. Counseling and antidepressants (used with caution, though, in light of their possible adverse effects on sexual function) can treat depression effectively, and appropriate lifestyle changes may relieve stress. Help may also be obtained from mental health professionals trained in dealing with sexual problems. Be sure to get a reliable referral from your doctor.
Oral medications
Several drugs are available for treatment of ED. They work by enhancing the effects of nitric oxide, which relaxes the smooth muscles in the penis. One such drug, sildenafil (Viagra®), was proven effective in men with diabetes. In one study, 252 diabetes patients were randomized to receive either sildenafil or a placebo for 12 weeks. At the end of the study, 56 percent of men taking sildenafil reported improved erections, compared with 10 percent of placebo patients. Sildenafil worked regardless of age or duration of diabetes or impotence, and its side effects were generally tolerable (the most common were headache and indigestion). Similar improvements in patients with diabetes have been shown with similar medications, vardenafil (Levitra®) and Tadalafil (Cialis®).
Nevertheless, sildenafil or similar drugs prescribed for ED should be used with caution because they are associated with some danger in people with cardiovascular disease. People taking long-acting or short-acting nitrates (primarily for angina) must not use them. The Food and Drug Administration warns against use in men who have suffered a heart attack, stroke or arrhythmia within the past six months or who have high or low blood pressure, a history of cardiac failure, angina or retinitis pigmentosa, a chronic eye disease. The patients in the aforementioned study had no more cardiovascular-related adverse events than the placebo patients, but all patients were carefully selected for good health and good blood glucose control. How sildenafil or similar drugs might affect a broader sample of diabetes patients is unclear. Some physicians suggest undergoing an exercise stress test before receiving a prescription.
Other options
Since the advent of prescription tablets for ED, other treatments have fallen somewhat out of favor because they are invasive and do not allow the same degree of spontaneity. Nevertheless, they have proved moderately effective in men with diabetes and remain viable alternatives.
Drugs that dilate the blood vessels, such as papaverine , phentolamine and alprostadil (Caverject®), can be injected directly into the penis to achieve an erection. Men should be screened for cardiovascular disease and prior transient ischemic attacks or strokes before using them, however. Their greatest danger is a sustained erection. Alprostadil pellets can also be placed in the urethra at the top of the penis.
Although cumbersome, vacuum devices, which pull blood into the penis by sucking away the air around it, are another option. The option of last resort is an implanted penile prosthesis. Although effective, these devices are associated with a long-term risk of mechanical malfunction and infection, especially in men with diabetes.
