Towards this direction, several sufficiently powered studies have demonstrated a higher incidence of erectile dysfunction in patients with coronary artery disease, either asymptomatic or overt. At the same time, patients with erectile dysfunction are more prone to have established coronary artery stenosis of more than 50% and consequently evident CV disease. This is in conformity with the “artery size hypothesis” according to which smaller arteries (e.g., penile arteries) are the first to undergo a vascular lesion prior to the larger ones (e.g., coronary arteries). Moreover, in such patients erectile dysfunction is connected to the number of occluded vessels and more interestingly occurs over three years before coronary artery disease becomes apparent[76-80].
SOURCES: American Urological Association, "AUA Guideline on the Management of Erectile Dysfunction: Diagnosis and Treatment Recommendations." Barksdale, J. Pharmacotherapy, May 1999; vol 19: pp 573-581. Ferrario, C. Journal of Clinical Hypertension, November/December 2002; vol 4: pp 424-432. Fogari, R. American Journal of Hypertension, January 2001; vol. 14: pp 27-31. Grimm, R. Hypertension, January 1997; vol 29: pp 8-14. Llisteri, J. American Journal of the Medical Sciences, May 2001; vol. 321: pp 336-341. WebMD Medical Reference provided in collaboration with The Cleveland Clinic: "Hypertension: Treatment With ACE Inhibitors."
Heart disease and erectile dysfunction can be related. In fact, ED and heart disease are considered two signs of the same disease process. The smaller arteries in the penis are affected by atherosclerosis sooner, perhaps three or more years before they cause heart disease symptoms.11 A large international study found that men with ED were more likely to die from heart causes; have a heart attack, stroke or be admitted to the hospital with heart failure than men with no or mild ED.12
Table 1 offers elements for distinction between organic and psychogenic disease.7 Of note is that in cases of organic origin, a psychogenic component may co-exist. The most common organic aetiology of ED is vasculogenic (see below ‘ED and CAD: common pathophysiology’).2,3 Co-existence of vascular disease, advancing age, and the presence of CVD risk factors and metabolic disorders increase the likelihood that ED is of vasculogenic aetiology.
The pathophysiological basis for the predictive ability of ED has been discussed above. It should be emphasized, however, that ED should not only be viewed as a manifestation of obstructive CAD that could be identified by ischaemia revealing tests. Owing to the inflammatory and pro-thrombotic activation of the disease,13 it should also be regarded as an early warning sign of an imminent acute event (mainly acute myocardial infarction)22 due to the rupture of a subclinical plaque, and thus identification of the risk should ideally include plaque vulnerability tests. Finally, an issue that has important clinical implications is by how long the clinical manifestation of ED precedes the clinical manifestation of CAD. According to studies, men with ED and no cardiac symptoms have an increased incidence of experiencing a cardiac event, both acute and chronic, in the ensuing 2–5 years, thus providing a ‘window of opportunity’ for risk reduction management in these patients.2
The wide range of prevalence rates noted among the studies can be attributed to a number of factors. First, prevalence rates are affected by the sensitivity and specificity of methods used to assess ED.1 In addition, a number of these studies used medical record review to identify patients with ED, as opposed to anonymous patient reports. It has been shown in other disease states that patients tend to underreport ED when questioned directly by their providers.3 Therefore, the use of validated questionnaires that are either self-administered in an anonymous, neutral setting or administered by an objective third-party interviewer are preferred.
Erectile dysfunction is a common occurrence in men with diabetes. The incidence of erectile dysfunction increases progressively with age, from 5% in men age 20 to 75% in men over age 65. The cause of erectile dysfunction in men with diabetes is usually related to a decrease in the blood supply to the penis as well as to injury to the nerves that are responsible for the erection mechanism. A decrease in testosterone production has also been identified as the cause in some men with diabetes.