Metabolic syndrome, a cluster of problems that can raise the risk of heart disease, is often associated with obesity, but new research indicates that people of normal weight can develop the condition too.

As reported in the journal Diabetes Care, Dr. Marie-Pierre St.-Onge, from the University of Alabama at Birmingham, and colleagues assessed the rate of metabolic syndrome among non-obese subjects by analyzing data from the Third National Health and Nutrition Examination Survey (NHANES III). Data from 7602 adults participants were included in the analysis.

Subjects were diagnosed with metabolic syndrome if at least three of the following were present: high triglycerides, low HDL “good” cholesterol, high blood pressure, high blood sugar, and large waist circumference.

In subjects at the low end of normal weight, the rate of metabolic syndrome ranged from 0.9 to 3.0 percent, depending on ethnicity and gender. In contrast, in slightly overweight individuals, the rates were considerably higher - between 9.6 and 22.5 percent.

The risk of metabolic syndrome increased as a person’s body weight rose from the low end of normal to slightly overweight.

Compared with low-normal weight men, those who were classified as mid-normal weight, upper-normal weight, and slightly overweight were 4.1-, 5.4-, and 9.1-times more likely, respectively, to develop metabolic syndrome.

The corresponding risks were even more pronounced in women, at 4.3-, 7.8-, and 17.3-fold higher.

“The high prevalence of metabolic syndrome in normal-weight and slightly overweight individuals warrants investigation of the impact of weight loss and physical activity in this population group,” the authors state.

Screening for the syndrome in such individuals “may be beneficial in the prevention of diabetes and cardiovascular disease,” they add.

SOURCE: Diabetes Care, September 2004.