Although the incidence and severity of erectile dysfunction increases with age, the most common pathologic risk factor for erectile dysfunction is believed to be diabetes. Erectile function appears to depend on nitric oxide production by nerves and on arteriolar smooth muscle relaxation. Penile artery flow is dependent on vascular endothelial function that is compromised by other risk factors for cardiovascular disease including hyperlipidemia, smoking, and hypertension. Endothelial dysfunction can result from these disorders and can progress to atherosclerosis. To evaluate the correlation between erectile dysfunction severity and the degree of coronary artery disease, Solomon and associates studied the presence and severity of erectile dysfunction in a cohort of men who underwent coronary angiography.
Participants were asked questions about erectile dysfunction using a standardized, validated erectile dysfunction measure, the International Index of Erectile Function-5 (IIEF) questionnaire, and were asked about the timing of the erectile dysfunction and their cardiovascular symptoms. Coronary artery disease was identified by a history of myocardial infarction, percutaneous angioplasty, coronary artery bypass grafting, or stenosis of greater than 50 percent in a coronary artery on angiography.
Based on verbal answers, 45 percent of the 132 subjects noted erectile dysfunction, although 65 percent had erectile dysfunction based on scoring of the IIEF questionnaire. Of the subjects who verbally reported erectile dysfunction, 58 percent noted erectile dysfunction symptoms before being diagnosed with coronary artery disease. Coronary angiography revealed that 78 percent of the subjects had some level of coronary artery disease. There was an inverse relationship between IIEF scores and cardiovascular risk factors and a positive relationship between the IIEF scores and use of aspirin or clopidogrel. Because a lower IIEF score means worse erectile function, these results show that cardiovascular risk factors are positively associated with erectile dysfunction, while the use of platelet-aggregation inhibiting medications improved erectile function.
The authors conclude that erectile dysfunction is associated with increased plaque burden as assessed by coronary angiogram. The fact that erectile dysfunction is a manifestation of atherosclerotic disease implies that questions about erectile dysfunction should be a part of routine cardiovascular screening, and all men with erectile dysfunction should be treated aggressively for any presenting cardiovascular risk factors.