Obesity diagnosis and treatment are typically based on body mass index (BMI) of at least 30. BMI is calculated as weight in kilograms divided by height in meters squared. However, three categories of obesity are defined: obesity 1 (30-34.9); obesity 2 (35-39.9); and extreme obesity (40 and greater). (A 5'4" person would have a BMI of 40 if they weighed 233 lbs). The latter 2 categories, sometimes termed severe obesity, are reported to be increasing especially rapidly in the United States, according to background information in the article. From 1986 to 2000, prevalence of BMI of 30 or higher approximately doubled, while that of BMI of 40 or higher quadrupled and that of BMI of 50 or higher increased 5-fold. In 2000, 2.8 percent of all U.S. women, and 6 percent of black women reported measurements consistent with extreme obesity. Estimates of obesity-related risks in women have generally been based on weight data that preceded the increase in extreme obesity. It has been unclear whether health risk increases or plateaus as body weight increases throughout the obese range.
Kathleen McTigue, M.D., M.S., M.P.H., of the University of Pittsburgh, and colleagues conducted a study to examine the relationship between weight category and risk of death and coronary heart disease (CHD) in a large population-based sample of U.S. women, focusing on risk across degree of obesity. The researchers analyzed data on incident death and cardiovascular outcomes by weight status in 90,185 women recruited from 40 U.S. centers for the Women's Health Initiative-Observational Study who were followed-up for an average of 7.0 years (Oct. 1993 to Aug. 2004).
The researchers found that extreme obesity prevalen
Source:JAMA and Archives Journals