Inactivity Increases Heart Failure Risk at All Weight Levels

By Charles Bankhead

BOSTON, 27 dec 2008- Excess weight and physical inactivity can almost triple a man's risk of heart failure, according to data from a large prospective cohort study. Obese, inactive men had almost a 300% greater risk of heart failure compared with lean, active study participants, Satish Kenchaiah, M.D., of Brigham and Women's Hospital and Harvard, and colleagues reported in the Jan. 6 issue of Circulation: Journal of the American Heart Association. For a man who is 5' 10" tall, every seven pounds of weight gain increased the risk of heart failure by 11%, the data suggested. The data also showed that excess weight and physical activity did not influence each other's effect on heart failure risk. "Higher [body mass index] increased the risk of heart failure in active and inactive men," Dr. Kenchaiah said. "By the same token, the beneficial effect of vigorous physical activity in reducing the risk of heart failure was observed in lean, overweight, and also obese men." Although BMI in the obese range (30 kg/m2) is associated with an increased risk of HF, the risk conferred in overweight or preobese (25 to 29.9 kg/m2) individuals had been unclear, the authors said. Numerous health benefits have been ascribed to physical activity, but its influence on the risk of heart failure also had remained unclear, particularly in men. Moreover, the interaction among BMI, physical activity, and heart failure risk had not been examined. To address the unknowns, Dr. Kenchaiah and colleagues analyzed data from the Physicians' Health Study. The analysis included 21,091 men ages 40 to 84 at enrollment and without known coronary heart disease. They completed annual health surveys since the PHS began in 1982. The authors examined the individual and combined effects of BMI and vigorous physical activity on heart failure incidence from 1982 to 2007. Vigorous activity was defined as exercise sufficient to cause sweating. The men were divided into BMI categories of lean (25 kg/m2), overweight (25 to 29.9 kg/m2), and obese (≥30 kg/m2). The authors applied a dichotomous definition to physical activity, defining inactive as rarely or never exercising vigorously and active as vigorous exercise one to three times a month. During follow-up that averaged 20.5 years, 1,109 participants developed new-onset heart failure. In a multivariate analysis, every 1-kg/m2 increase in BMI increased the risk of heart failure by 11%. As compared with lean participants, overweight men had a 49% increase in the risk of heart failure, and obese men had a 180% greater risk. Overall, the data on physical activity showed that men who exercised vigorously five to seven times a week had a 36% reduction in heart failure risk compared with men who reported no physical activity. As compared with men who were both lean and physically active, heart failure risk increased: 19% in the lean and inactive 49% in the overweight and active 78% in the overweight and inactive 168% in the obese and active 293% in the obese and inactive "Whereas previous studies have established that obese men have a higher likelihood of developing heart failure, the present investigation has extended this knowledge by pointing out that even overweight or pre-obese men are not spared from this increased risk," said Dr. Kenchaiah. The study was supported in part by the National Heart, Lung and Blood Institute and the National Cancer Institute. Dr. Kenchaiah reported no potential conflicts of interest.

Primary source: Circulation: Journal of the American Heart Association Source reference: Kenchaiah S, et al "Body mass index and vigorous physical activity and the risk of heart failure among men" Circulation. 2009; 119: DOI: 10.1161/CIRCULATIONAHA.108.807289.