Diabetes and erectile dysfunction linked to heart disease
Posted Sep 22 2008 11:03am
Two new studies involving men with type 2 diabetes have found that erectile dysfunction (ED) was a significant early warning sign for serious heart disease.
The research carried out in Hong Kong highlights the need for men to report erectile dysfunction to their GPs so treatment can be focused on overcoming ED and improving overall cardiovascular health.
"The development of erectile dysfunction should alert both patients and healthcare providers to the future risk of coronary heart disease,” said Peter Chun-Yip Tong, Ph.D., an associate professor in the Department of Medicine & Therapeutics at The Chinese University of Hong Kong, Prince of Wales Hospital, Hong Kong.
"Other risk factors such as poor blood glucose control, high blood pressure, high cholesterol levels, smoking and obesity should be reviewed and addressed aggressively."
Diabetes, erectile dysfunction and heart disease share a common link to damage of the blood vessels through high blood sugar levels. This process also hinders the added blood flow needed to maintain an erection as well as having serious consequences to the heart.
"The first event is probably endothelial dysfunction—when the smoothness and reactivity of the blood vessel are damaged," said Dr. Tong.
"This process encourages local inflammation on the inner surface of the blood vessels and the deposition of cholesterol, resulting in formation of clots and atherosclerosis. Therefore, there is a high risk of blockage of blood vessels in the heart, which can lead to a heart attack."
Signs of erectile dysfunction appear typically more than three years before the onset of coronary heart disease symptoms. In one study, ED symptoms always preceded coronary symptoms in diabetic men.
The Hong Kong study involved 2,306 men with type 2 diabetes following them for an average of four years. Just over 25% of participants had ED at the beginning of the study and none of the participants had any signs or history of heart disease, vascular disease or stroke.
Over the period of the research, 123 men suffered either a heart attack, died from heart disease or developed chest pain caused by clogged arteries. Others required bypass surgery or catheters to restore blood flow to the heart.
Of every 1,000 diabetic men with ED, nearly 20% could be expected to suffer a coronary heart disease (CHD) event compared to nearly 10% without ED.
Even when different characteristics associated with CHD such as age, blood pressure, duration of diabetes and damage to kidneys or eyes were taken into account, men with ED had a 58% increased risk of a coronary heart disease event.
The second study, conducted by researchers from four medical centers in Italy, focused on 291 men who not only had type 2 diabetes but also silent CHD discovered by stress testing and confirmed by x-ray angiography. Of these, 118 had ED at the beginning of the study. Lead investigator Carmine Gazzaruso, M.D., Ph.D., and his colleagues followed-up patients for an average of nearly four years, documenting major adverse cardiac events (MACE), which they defined as not only CHD events but also stroke, mini-stroke (transient ischemic attacks) and arterial disease in the legs. They found that patients who had ED at the beginning of the study were twice as likely to suffer a major adverse cardiac event when compared to those without ED.
The study also showed that among patients who were taking cholesterol-lowering statins, the risk of MACE was reduced by one third (hazard ratio, 0.66, p = 0.036). Viagra and other medications in a family known as 5-phosphodiesterase (5PDE) inhibitors also appeared to reduce the MACE risk (hazard ratio, 0.68); however this finding was just beyond the cusp of being statically significant (p = 0.056).
"These are important studies," said Robert A. Kloner, M.D., Ph.D., F.A.C.C., a professor of medicine at the Keck School of Medicine at the University of Southern California, and director of research for the Heart Institute at Good Samaritan Hospital in Los Angeles.
"While we have known that ED shares many common risk factors with CHD, such as hypertension, smoking, dyslipidemia and diabetes, what is new here is that ED remained a significant risk factor for developing heart disease after controlling for other cardiovascular risk factors.
“Men should know that ED is a true harbinger of atherosclerotic coronary heart disease,” he said.