News:Better to be a pear than an apple: new prospective look at associations between fat distribution and coronary heart disease

December 14, 2007 By Benjamin A. Olenchock, M.D. Ph.D. [mailto:bolenchock@partners.org]

Cambridge

Using the EPIC-Norfolk study, investigators followed over 24,500 men and women for an average of 9 years. Baseline data were collected, including waist circumference, hip circumference, height/weight (body mass index), smoking status, alcohol intake, lipid profile, activity level, family history of heart disease, blood pressure and age. The patients in this cohort were on average 60 years old, had stage 1 hypertension, and were overweight (mean body mass index ~26). Most men had smoked in the past or currently (~70%) while most women had not (~40% current or past smoker). Ten percent of the men and 4% of the women had a previous diagnosis of coronary disease, stroke, or diabetes. Calculated hazard ratios were adjusted for these baseline data, including body mass index.

The authors observed 2600 coronary heart disease events over a mean follow-up of 9 years. After adjustment for covariates, there remained a linear association between waist-hip ratio and coronary events. Waist circumference alone was also associated with increased coronary events, but this measure was less predictive without normalizing to hip size, and the trend was more obvious in women than in men. In both sexes, BMI was also linearly associated with coronary risk, but the hazard ratios were greatly attenuated after adjustment for waist and hip size. For every 0.5-increase in waist-hip ratio, the hazard ratio for acute myocardial infarction was 1.13 (CI 1.05 to 1.23) in men and 1.25 (CI 1.13 to 1.39) in women. The association between waist-hip ratio and coronary events was greatest for those at lowest risk.

This large, prospective trial adds support to the hypothesis that fat distribution is more important than total body fat. There is substantial evidence that visceral adiposity is associated with insulin resistance and atherogenic lipid profiles associated with the metabolic syndrome, while peripheral adiposity is more benign. Perhaps all clinics should be equipped with a tape measure in addition to a scale.

Dexter Canoy, S. Matthijs Boekholdt, Nicholas Wareham, Robert Luben, Ailsa Welch, Sheila Bingham, Iain Buchan, Nicholas Day, and Kay-Tee Khaw. 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: published online before print December 10, 2007, 10.1161/CIRCULATIONAHA.106.673756.