When the hormone insulin, which normally helps cells take up glucose for energy, is unable to work effectively, a number of changes occur that are collectively called the insulin resistance syndrome, the metabolic syndrome or Syndrome X. These include high blood pressure, high blood sugar and cholesterol levels, and overweight (especially abdominal obesity). A combination of such changes may be as strong a contributor to the risk of heart disease as cigarette smoking. Researchers from Duke University in North Carolina studied whether exercise and diet have an effect on these risk factors. They published their findings in Archives of Internal Medicine.

Forty-one adults with Syndrome X - high to high-normal blood pressure, high blood sugar and cholesterol levels - completed a 6-month study. They were divided into 3 groups: exercise only, exercise and weight loss, or a control group. Those in the "exercise only" group walked or jogged for 35 minutes (and did warm-up and cool-down exercises for an additional 20 minutes) 3 to 4 times a week. The "exercise and weight loss" group did the same amount and intensity of exercise, but also attended weekly weight management classes; the classes were small (3 to 4 people) and focused on a gradual weight loss of 1 to 2 lbs a week with a low-calorie, low-fat eating plan. Those in the "control" group were encouraged to maintain their usual food and exercise habits.

Exercise plus diet equals improved health

Six months later, the volunteers assigned to either treatment group had improved their glucose tolerance - their blood insulin levels did not rise abnormally in response to a glucose drink. The greatest improvement was derived from the combination of exercise and weight loss. Those assigned to that group also had lower blood pressure readings and lost an average of 22 lbs. The exercise-only group lost weight, too, but only an average of about 4½ lbs. Blood lipids weren't altered by either treatment.

Approximately 25% of the population may be insulin resistant and are likely to develop the accompanying problems of high blood pressure and high cholesterol. The researchers note that these findings are valuable because some medications for treating high blood pressure can have adverse effects on blood sugar and cholesterol levels, whereas exercise and weight loss lower the risk of heart disease without any undesirable side effects of medication.

Support needed

The volunteers in this study had ongoing support and supervision to help them make changes to their diet and physical activity habits. Enlist support from friends, family, the local gym, or community center to help you make heart healthful changes, if necessary. If you have one or more of the Syndrome X 'markers', you'll benefit from a combination of tactics that include healthful eating, exercising, and, of course, support from your physician.