As the number of overweight and obese Americans continues to increase, so does the incidence of a newly recognized disorder called metabolic syndrome. Also known as "syndrome X" and "insulin resistance syndrome," metabolic syndrome is not a single disease but rather a cluster of health problems that together appear to increase a person’s risk for several chronic diseases. Scientists believe the syndrome is caused by a combination of genes and lifestyle factors, including overeating and being sedentary.
According to a recent national survey, one in five adults in the U.S. has metabolic syndrome, many of whom are unaware they have the syndrome. The incidence increases with age, affecting more than 40 percent of those in their 60s and 70s. Individuals classified as having metabolic syndrome typically are thick around the middle and have borderline high levels of blood pressure, blood sugar and triglycerides and lower than desirable levels of HDL (good) cholesterol. Clinically, the National Institutes of Health defines metabolic syndrome as having three or more of the following conditions: a waist circumference of 40 inches or more in men and 35 inches or more in women, blood triglyceride levels of 150 milligrams per deciliter or higher, HDL cholesterol levels of less than 40 milligrams in men and less than 50 milligrams in women, a blood pressure reading of 135/80 mmHg or higher, and fasting blood sugar levels of 110 milligrams/deciliter or higher.
How does metabolic syndrome develop? Often in overweight and inactive individuals, cells gradually become unable to recognize insulin, thereby preventing insulin from doing its job of removing sugar from the bloodstream and depositing the sugar into cells. The body continues to produce insulin in an attempt to clear sugar from the bloodstream, resulting in high blood sugar and high insulin levels. Over time, the large amounts of insulin in the blood elevate blood pressure and increase blood levels of triglycerides, while causing HDL (good) cholesterol levels to decrease. Together, these occurrences lead to metabolic syndrome.
Because metabolic syndrome puts you at higher risk for several chronic diseases, recognition and treatment of the syndrome are important. For example, type 2 diabetes is often preceded by years of metabolic syndrome. In fact, it’s estimated that one-third to one-half of those who have metabolic syndrome will eventually develop diabetes. Further, the changes in triglyceride and HDL cholesterol levels, along with the increased blood pressure seen with metabolic syndrome can lead to heart disease and/or stroke. Lastly, a link between high levels of insulin and some types of cancers, including pancreatic, breast and colon, has been found in several population studies.
If you have or are "inching" your way toward metabolic syndrome, the best way to fight back is to lose weight and increase your activity. Losing even a few pounds has been shown to improve the body’s ability to recognize insulin. Also, increased activity, even without weight loss, may improve insulin sensitivity. The key is to start at a level you’re comfortable with and work up to 30 to 60 minutes of dedicated activity each day, spread out in manageable increments.
In the food choice area, a recent Harvard Medical School study points to the importance of making sure your diet includes a good selection of fiber-containing fruits, vegetables and whole grains along with low-fat dairy products. In this study of 3,000 18-30 year olds followed over 10 years, those whose diets were high in dairy products (about three servings a day) were seven times less likely to develop metabolic syndrome over the 10-year period than those whose diets were low in dairy products. People with diets high in fiber also were less likely to develop metabolic syndrome.
Finally, it’s a good idea to double-check your prescriptions. Some blood pressure medications improve insulin resistance (e.g. angiotensin receptor blockers), while others tend to aggravate it (e.g. diuretics and beta blockers).
If you think you might be a "silent sufferer" of metabolic syndrome or to learn more about the disorder, contact your physician or a registered dietitian.