What Is Metabolic Syndrome?

Metabolic syndrome is the name for a group of risk factors linked to overweight and obesity that increase your chance for heart disease and other health problems such as diabetes and stroke. The term “metabolic” refers to the biochemical processes involved in the body’s normal functioning. Risk factors are behaviors or conditions that increase your chance of getting a disease. In this article, “heart disease” refers to coronary heart disease.

The five conditions listed below are metabolic risk factors for heart disease. A person can develop any one of these risk factors by itself, but they tend to occur together. Metabolic syndrome is diagnosed when a person has at least three of these heart disease risk factors:

• A large waistline. This is also called abdominal obesity or “having an apple shape.” Excess fat in the abdominal area is a greater risk factor for heart disease than excess fat in other parts of the body, such as on the hips.
• A higher than normal triglyceride level in the blood (or you’re on medicine to treat high triglycerides). Triglycerides are a type of fat found in the blood.
• A lower than normal level of HDL cholesterol (high-density lipoprotein cholesterol) in the blood (or you’re on medicine to treat low HDL). HDL is considered “good” cholesterol because it lowers your chances of heart disease. Low levels of HDL increase your chances of heart disease.
• Higher than normal blood pressure (or you’re on medicine to treat high blood pressure). Blood pressure is recorded as two numbers, usually written one on top of or before the other, such as 120/80. The top or first number, called the systolic blood pressure, measures the pressure in the bloodstream when your heart beats. The bottom or second number, called the diastolic blood pressure, measures the pressure in your bloodstream between heartbeats when the heart is relaxed.
• Higher than normal fasting blood sugar (glucose) (or you’re on medicine to treat high blood sugar). Mildly high blood sugar can be an early warning sign of diabetes.

The more of these risk factors you have, the greater your chance of developing heart disease, diabetes, or a stroke. In general, a person with metabolic syndrome is twice as likely to develop heart disease and five times as likely to develop diabetes as someone without metabolic syndrome.

Other risk factors aside from those of the metabolic syndrome also increase your risk for heart disease. A high level of LDL cholesterol (low-density lipoprotein cholesterol; considered “bad” cholesterol) and smoking, for example, are key risk factors for heart disease, but they aren’t components of metabolic syndrome. Even a single risk factor raises your risk for heart disease, and every risk factor should be lowered to reduce the risk.

The chance of developing metabolic syndrome is closely linked to being overweight or obese and to a lack of physical activity. Another cause is insulin resistance. Insulin resistance is a condition in which the body can’t use its insulin properly. Insulin is a hormone the body uses to help change blood sugar into energy. Insulin resistance can lead to high blood sugar levels and is closely linked with being overweight or obese.

Genetics (ethnicity and family history) and older age are other important underlying causes of metabolic syndrome.

Outlook

About 47 million adults in the United States (almost 25 percent) have metabolic syndrome, and the numbers continue to grow. The increasing number of people with this condition is connected to the rise in obesity rates among adults. In the future, metabolic syndrome may overtake smoking as the leading risk factor for heart disease.

It’s possible to prevent or delay metabolic syndrome, mainly with lifestyle changes. A healthy lifestyle is a lifelong commitment. Successfully controlling metabolic syndrome takes a long-term effort and teamwork with your health care providers.

April 2007