BUFFALO, N.Y. -- Long-term follow-up of participants in a health study that began in 1960 has shown that men who were younger than 65 at that time and moderately overweight had a greater risk of dying from any cause, and from heart disease in particular, than their counterparts who were not overweight.
Researchers at the University at Buffalo found that men who were less than 65 and fell into the study's highest category of overweight with a body mass index (BMI) of 27.5 had a 67 percent increased risk of overall mortality compared to those in the lowest weight range. The BMI is a measure of relative weight, calculated by dividing weight in kilograms by height in meters squared. A BMI in the range of 20-25 is considered acceptable for most people.
In older men, being overweight was not related to mortality.
For women, being overweight posed a significant heart-disease mortality risk at any age, the study showed. Those in the highest BMI category of obesity were 2 1/2 times more likely to die of heart disease than women with a lower BMI, said Joan Dorn, Ph.D., UB assistant professor of social and preventive medicine and lead author on the study.
Being even moderately overweight increased women's risk of dying from heart disease, Dorn said, but the risk did not reach statistical significance until a BMI of 27.1.
"For women, this study clearly shows you don't have to be obese to have an increased risk of dying from heart disease," she noted.
The study is published as the lead article in the Dec. 2 issue of the American Journal of Epidemiology, which is dedicated to research by faculty members and graduates of the UB Department of Social and Preventive Medicine.
The objective of the research was to determine whether, in a general population, being overweight contributed significantly to a person's risk of dying from any cause, and to the risk of death from coronary heart disease, cardiovascular disease or cancer, in particular, over the long-term.
Dorn and colleagues based their study on a 29-year follow-up of 611 men and 697 women who participated in the Buffalo Health Study, which began in 1960. Extensive health data and lifestyle information were collected at that time from a population-based sample of black and white men and women between the ages of 15 and 96.
Of the white participants, 295 men and 281 women died between 1960 and 1989, when follow-up began. Only data from white participants were included in this study because follow-up was not completed for black participants.
Overweight status was based on the BMI. Men and women were placed into four BMI categories, or quartiles, based on their weight and height in 1960. Researchers conducted an extensive investigation using a variety of sources to verify participants who were still living. Date and cause of death were obtained from death certificates.
Analysis of the relationship of BMI in 1960 to overall mortality and specific causes of death over the intervening 29 years revealed a number of pertinent associations:
"Coronary heart disease remains the leading cause of death in the U.S.," Dorn said. "Given that about one-third of American adults weigh at least 20 percent more than they should and the trend is worsening, these findings provide strong support for prevention and treatment of overweight in men and women."
Additional researchers involved in the study were doctoral candidate Enrique F. Schisterman and Maurizio Trevisan, M.D., professor and chair of the UB Department of Social and Preventive Medicine, and Warren Winkelstein, M.D., formerly of UB, now professor emeritus at the School of Public Health, University of California at Berkeley.
American Journal of Epidemiology