Metabolic Syndrome - Recognizing And Reducing Risk Factors: Heart Disease

Content provided by the Faculty of the Harvard Medical School

Metabolic syndrome

About 47 million American adults have metabolic syndrome, sometimes also known as syndrome X and various other names. Regardless of what you call it, this constellation of heart-risky attributes increases the risk of developing diabetes and coronary artery disease. Anyone with three or more of the following attributes meets the diagnostic criteria for metabolic syndrome:

• a large waist size (greater than 40 inches in men or 35 inches in women)

• blood pressure that is 130/85 mm Hg or higher

• HDL cholesterol that is less than 40 mg/dL in men and less than 50 mg/dL in women

• triglyceride level that is 150 mg/dL or higher

• fasting blood glucose level of 110 mg/dL or higher.

Metabolic syndrome often develops when the body's cells become resistant to the effects of insulin. As a result, blood sugar cannot enter cells and builds up in the bloodstream, causing a cascade of other problems. It is not clear why this happens, but gaining weight, especially in the abdominal area, and getting too little exercise both contribute to the disorder in people who have a genetic susceptibility. If you think of your body as a biological engine, then the combination of eating too much and not moving enough to burn the fuel is a bit like constantly flooding your internal engine; after a while, it just doesn't work as well as it used to.

When blood sugar levels remain high, other harmful changes occur. These include damage to the lining of coronary and other arteries; problems with enzymes that break down fats, which increase triglyceride levels; changes in how the kidneys handle salt, which raises blood pressure; and a greater tendency of the blood to form clots. Continued high blood sugar initially causes the pancreas to overproduce insulin, but eventually the organ burns out and type 2 diabetes may develop. All of these changes increase the risk for cardiovascular disease, heart attack, and stroke. Men with metabolic syndrome are twice as likely as others to develop cardiovascular disease, and four times as likely to die from it. Risk also increases in women, although it hasn't been as well quantified.

Fortunately, it is possible to prevent metabolic syndrome from developing, or to lessen its heart-harmful effects if you already have it, by following the same strategies to prevent and treat coronary artery disease. The basics? Lose weight, eat heart-healthy foods, exercise regularly (see "Lifestyle changes to protect yourself"), and take medications if you need them (see "Medications for heart disease").

Last updated:	May 03, 2007