August 11, 2008 — (BRONX, NY) — Researchers at the Albert Einstein College of Medicine of Yeshiva University analyzed a nationally representative sample of Americans and found that you just can't generalize about the link between obesity and heart disease: A considerable proportion of overweight and obese people are healthy, while quite a few normal-weight Americans have cardiovascular abnormalities. The study was led by Dr. Rachel P. Wildman, assistant professor of epidemiology & population health at Einstein, and appears in the August 11/25 issue of Archives of Internal Medicine.
As a general rule, obesity — which is increasing in prevalence worldwide — puts people at increased risk for developing type 2 diabetes and heart disease. But factors besides obesity can significantly influence heart-disease risk. The Einstein study, for example, adds to growing evidence that abdominal visceral fat (measurable by waist circumference) heightens heart-disease risk even in normal-weight people.
Dr. Wildman and her colleagues looked at data collected on 5,440 adults age 20 and over who had participated in the National Health and Nutritional Examination Surveys between 1999 and 2004. They divided participants into three weight classes (normal weight, overweight and obese) and assessed them for six heart-disease risk factors including hypertension, elevated triglycerides and low levels of high-density lipoprotein ("good") cholesterol. Individuals were considered "metabolically healthy" if they had none or one risk factor and "metabolically abnormal" if they had two or more of them.
"We found that 23.5 percent of normal-weight adult Americans — or about 16.3 million people — are metabolically abnormal when it comes to heart-disease risk," says Dr. Wildman. "At the same time, 51.3 percent of overweight adults and 31.7 percent of obese adults were metabolically healthy. We were surprised by these figures, particularly by the number of obese people who had a healthy cardiovascular risk factor profile."
Dr. Wildman further noted that normal-weight people with risk factors tended to be older, physically less active and to have a larger waist circumference compared with healthy, normal-weight people. And that obese people with no risk factors were more likely to be younger, black, more physically active and to have smaller waists than obese people with risk factors.
Among the study's other findings:
Other Einstein researchers involved in the study were Aileen P. McGinn, Swapnil Rajpathak and Judith Wylie-Rosett.