Waist-Hip Ratio Predicts Risk of Coronary Artery Disease

MANCHESTER, England, Dec. 10 -- A standard measuring tape showing the ratio of fat distribution between the waist and hip can predict coronary artery disease better than body mass index or waist circumference alone, according to investigators here.
Action Points --->
Explain to interested patients that this study suggests that weight reduction that reduces abdominal girth may reduce the risk of cardiovascular events.
Explain to interested patients that BMI, waist circumference, and waist-hip ratio were all associated with increased risk of cardiovascular disease in both men and women.
Men who had the highest waist-hip ratio were 55% more likely to have coronary artery disease than men in the lowest quintile, said Dexter Canoy, M.Phil., M.D., Ph.D., of the University of Manchester, and colleagues, reported online today by Circulation: Journal of the American Heart Association.
For women in the top quintile there was a 91% increase in risk versus women in the lowest fifth, the investigators added.
Waist and hip girths are closely correlated, but both can benefit from weight loss. "Our findings suggested that reducing weight by 1 kg (for a given height) could translate into reducing coronary heart disease risk by 2% in both men and women. Alternatively, reducing waist circumference by 5 cm could lower risk by 11% in men and 15% in women," Dr. Canoy and colleagues wrote.
Those reductions in weight and girth "are achievable with dietary restriction and low-intensity walking three times per week."
Dr. Canoy said that although waist circumference by itself was a reliable marker for heart disease, "risk estimates for waist circumference without hip circumference were lower by 10% to 18%."
Dr. Canoy wrote that BMI, waist circumference, and waist-hip ratio were all "directly related to the development of coronary heart disease, but the magnitude and shape of the associations were influenced by adjustments for possible mediating biological factors and potential confounders."
But "regardless of the model used, waist-hip ratio was independently more consistently predictive of coronary heart disease than waist circumference or body mass index in both men and women," they wrote.
Even among lean individuals, defined as those with a BMI of less than 25 kg/m2 , those with higher waist-hip ratio had about a 50% higher risk than those with lower waist-hip ratios, they wrote.
The waist-hip ratio, he said, was a simple tool to assess body fat distribution.
The finding emerged from the EPIC-Norfolk (European Prospective Investigation Into Cancer and Nutrition in Norfolk) study, a population-based prospective study, which followed 24,508 men and women for a mean of 9.1 years. The mean age of the participants was 60 and all were recruited from general practices in Norfolk, England, from 1993 through 1997.
Twelve percent of men and 11.2% of the women were current smokers and 55.3% of the men were former smokers, as were 32.5% of the women. About 30% of the sample said they had a sedentary lifestyle. The mean BMI was 26.6 kg/m2 for men and for women it was 26.3 kg/m2 .
Waist and hip were measured at enrollment using a standard measuring tape. In addition, the researchers obtained baseline BMI, blood pressure, and serum lipids. Participants also completed a standard questionnaire that assessed medical history, exercise, smoking, and alcohol use.
During follow-up there were 2,600 coronary disease events (1,708 in men), including 662 fatal and 1,938 nonfatal events.
Dr. Canoy said that variation in risks associated with distribution might "reflect differences in metabolic characteristics between abdominal fat and peripheral body fat. Increased abdominal obesity could indicate increased visceral fat accumulation, which is associated with elevated lipolysis, and portal fatty acid efflux, thereby promoting an atherogenic lipid profile, decreasing hepatic clearance of insulin, and increasing peripheral hyperinsulinemia."
Dr. Canoy said more accurate measures of fat distribution may be needed to improve risk assessment in specific subgroups.
The EPIC-Norfolk study is supported by Cancer Research U.K. and the Medical Research Council, with additional support from the Stroke Association, British Heart Foundation, Department of Health, Europe Against Cancer Program, Commission of the European Union, Food Standards Agency, and Wellcome Trust.
Dr. Canoy was supported by the Cambridge Commonwealth Trust/Cambridge Overseas Trust, and Christ's College.
Primary source: Circulation: Journal of the American Heart AssociationSource reference:Canoy D, et al "Body fat distribution and risk of coronary heart disease in men and women in the European Prospective Investigation into Cancer and Nutrition in Norfolk cohort: a population-based prospective study" Circulation 2007; DOI: 10.1161/CIRCULATIONAHA.106.673756.