Research&Technology ­
Peril by the Pound: Obesity raises risk regardless of lifestyle

"It has been postulated that obesity alone was not a risk factor," said Joan P. Dorn, UB assistant professor of social and preventive medicine and the study's lead author. "It was thought the real culprits were high blood pressure or smoking or inactivity, health problems that frequently accompany obesity.

"But in this study, we adjusted for all these factors, and body mass index (a ratio of weight to height and a standard indicator of obesity) came out by itself as a risk factor for dying from any cause, and especially as a risk for death from coronary heart disease."

Dorn presented the results recently at the annual meeting of the American College of Sports Medicine in Cincinnati.

Researchers conducted a 29-year follow-up of 611 men who participated in a 1960 population-based study in Buffalo. Health data, including height, weight and physical activity, were collected from the participants, who were between the ages of 20 and 96 in 1960. In the 29 years since the initial interviews, 295 men had died, 108 from coronary heart disease.

Body mass index (BMI), a number arrived at by dividing weight by height squared, was used to determine obesity. A body mass index of between 20-25 is considered acceptable for most people, Dorn noted, but even within that range, the risk of potential health problems increases as weight increases. (An example of a person with an acceptable body mass index would be an individual 5'5" tall weighing 120-126 pounds, which results in a body mass index of 20 to 21.)

Dorn and colleagues found that a body mass index of 27 or higher was significantly associated with death from all causes, and the relationship was stronger yet for death from coronary heart disease.

"With every six- or seven-pound increase in weight, which represents approximately one-unit increase in the BMI, our results show that there is an 4 percent increase in risk of dying from any cause," Dorn said. "For heart disease, one unit of increase in the BMI was associated with a 9 percent increase in risk.

"The bottom line is, even if you are physically active and otherwise healthy, if you are obese, you are putting your life at risk," Dorn said.

Contributors to the study were Maurizio Trevisan, professor and chair of the UB Department of Social and Preventive Medicine, and Warren Winkel-stein, formerly of UB, now at the School of Public Health, University of California at Berkeley.