To better quantify the health risks associated with obesity, the Pitt researchers, collaborating with researchers from six other institutions, examined the rates of death and of newly diagnosed coronary heart disease over a seven year period of 90,185 women in five specific weight categories. The women, all participants of the Women's Health Initiative-Observational Study, were assigned to the weight categories based on the weight-to-height ratio known as body mass index (BMI): normal (BMI 18.5 24.9), overweight (BMI 25.0 29.9), obesity 1 (BMI 30.0 34.9), obesity 2 (BMI 35.0 C 39.9) and extreme obesity (BMI 40).
The study showed that white women in the obesity 1 category (approximately 60 pounds above a normal weight for a 5-foot, 5-inch tall woman) to have a 12 percent higher risk of death over the seven year follow-up period, but extremely obese women (approximately 110 pounds above a normal weight for a 5-foot, 5-inch tall woman) had an alarming 86 percent higher risk of death than their normal weight counterparts.
Death rates increased substantially with increasing weight category, ranging from 68.39 deaths per 10,000 person-years in women with normal BMIs to 116.85 deaths per 10,000 person-years in extremely obese women.
The study findings, according to lead author Kathleen McTigue, M.D., M.P.H., assistant professor of medicine and epidemiology, division of internal medicine, University of Pittsburgh School of Medicine, suggest that the parti