How does diabetes cause erectile dysfunction?

Men with diabetes are at greater risk for erectile dysfunction (ED) and may experience it earlier in life than men who don't have diabetes.

Erectile dysfunction is defined as the inability to achieve or sustain an erection that is rigid enough for sexual intercourse.

The main risk factors for ED in diabetic individuals are neuropathy, vascular insufficiency, poor glycemic control, hypertension, low testosterone levels, and a history of smoking.

The General Problem

ED is an emotionally sensitive issue. Erections and intimate pleasure depend on healthy blood circulation and nerve endings, two areas of the body often affected by diabetes.

In our digestive system, food is broken down into a sugar called glucose that enters the blood stream to fuel cell growth and provide energy. A hormone called insulin is necessary for the body to transport glucose out of the blood stream and into fuel-hungry cells.

People with diabetes produce too little or no insulin to manage glucose, so their blood glucose levels are unstable. Having high blood glucose levels can lead to nerve and blood vessel damage.

The Specific Problems

1. Neuropathy. Nerve damage, or neuropathy, caused by diabetes may occur anywhere in the body, including the penis. Damaged nerves cannot effectively send or receive signals from each other or the brain, so the “up” signal may get lost when a man attempts intercourse.
2. Atherosclerosis. Atherosclerosis is the hardening or narrowing of blood vessels, and there is an association established between diabetes and accelerated atherosclerosis. If blood vessels in the penis become narrow or hard, too little blood and oxygen can flow there for proper functioning, and may also have an ill effect on genital blood pressure.
3. Nitric Oxide. Having poor blood glucose control can interfere with the body’s production of various chemicals, including nitric oxide. In the penis, nitrous oxide functions as a neurotransmitter - or a nerve signal carrier - necessary for the initiation and maintenance of an erection. When nitrous oxide levels are low, pressure from the blood may not build up enough to sustain penile engorgement.
4. AGEs. ED can also be caused by the stiffening of erectile tissue. Advanced Glycation End-Products (AGEs) are damaging byproducts of glucose metabolism and are associated with tissue stiffening that causes valve dysfunction in the corpora cavernosa. This dysfunction, called “venous leak,” can lead to severe ED that is not always helped by erection medications such as Levitra, Viagra, or Cialis.
5. Mental Health. Diabetes and depression are often experienced together, and mental health issues such as depression can interfere with intercourse or may cause a lack of interest in sex. Even severe stress or concerns about sexual performance can trigger ED. Unfortunately, some medications that treat psychological problems (e.g., some antidepressants) decrease libido as well.
6. Hormones and Other Things. Normal erections require normal thyroid levels and the correct balance of hormones, including testosterone and estrogen. Obesity can upset an individuals hormone balance, as can excessive alcohol consumption. Men with chronic liver or kidney disease may also experience ED.

Sources: Diabetes Journal; Sex Health Matters; Mayo Clinic; Dr Weil
Photo credit: Vladimir Pustovit / flickr creative commons