Erectile dysfunction (ED) is defined as the inability of the male to achieve or maintain an erection sufficient for sexual intercourse.
- Massachusetts Male Aging Study (MMAS) revealed that 52% of 1,290 men aged 40–70 had some degree of dysfunction, and 10% had total absence of erectile function.
- MMAS revealed a deleterious epidemiologic link between coronary artery disease, diabetes, and ED.
The overall incidence rate is estimated at 26 cases per 10,000 man-years; the rate increases with age and the presence of such factors as lower level of education, diabetes, heart disease, and HTN. New cases of specific disease (ED) per population at risk expressed as percentage.
ED affects as many as 30 million men in the United States.
- The prevalence and incidence is higher in the elderly.
- Higher incidence of predisposing risk factors for ED in the elderly
- Higher sensitivity to the medications that cause ED in the elderly
- Age: Men >40 yr
- HTN with or without treatment (>140/40)
- DM (fasting blood glucose <125 mg 70%)
- Family history of heart disease in primary relative: Male <55
- Elevated LDL cholesterol/triglycerides (>100 mg/dL)
- Low HDL cholesterol (<40 mg/dL)
- Cigarette smoking/passive smoking
- Central obesity associated with the metabolic syndrome
- Physical inactivity
- Elevated homocysteine, lipoprotein(a), C-reactive protein, fibrinogen, factor VIII, factor VII
Close link between ED and vascular disease; therefore, polygenic inheritance with clustering of the risk factors in families
- Ideal body weight
- Regular aerobic exercise
- Prevention of endothelial dysfunction through risk factor modification
Plaque starts to clog small arteries in the penis before the arteries in the coronary, cerebral, and peripheral arteries. With sexual stimulation nitric oxide (NO) is released into the corpora cavernosa from nonadrenergic-noncholinergic autonomic nerves and the vascular endothelium. NO stimulates the enzyme guanylate cyclase to produce cyclic guanosine monophosphate (cGMP), which ultimately causes relaxation in the vascular smooth muscle of the arteries, arterioles and sinusoids of the corpora cavernosa, which then fills with blood like a sponge fills with water. The blood is trapped in the penis (tumescence). A frequent underlying cause of ED is lack of cGMP. Erectile dysfunction may occur ~3 yr before coronary events or stroke.
- Unknown; associated with the risks contributing to atherosclerosis
- Causes include alcohol, anticholinergics, antihypertensive (thiazide diuretics, reserpine,
-blockers, methyldopa, hydralazine), cancer chemotherapeutics, clofibrate, gemfibrozil, digoxin, statins, H2 receptor antagonists, and tranquilizers. Other causes include:
- Hypogonadism, hypothyroidism, hyperthyroidism, pituitary tumor, hyperprolactinemia
- Cerebrovascular accidents, multiple sclerosis, nerve damage post prostrate surgery, neuropathies, spinal cord injuries
- Peyronie disease, priapism, trauma
- Psychogenic
COMMONLY ASSOCIATED CONDITIONS 
- Vascular disease (coronary, cerebral, peripheral)
- DM
- Elevated lipids (total cholesterol >240, HDL >60 was protective)
- Smoking
- HTN
- Obesity
- Sedentary lifestyle
3 risk factors (excluding gender), moderate stable angina, a recent MI (>2 wk and <6 wk) in patients who have not undergone revascularization, asymptomatic LV dysfunction with ejection fraction <40%, or NYHA class 2 heart failure, peripheral vascular disease, or recent stroke or transient ischemic attack (TIA).