A standardised case-control study 1 of acute myocardial infarction with 27 098 participants in 52 countries representing several major ethnic groups assessed the relation between BMI, waist and hip circumferences, and waist-to-hip ratio to myocardial infarction. BMI showed a modest and graded association with myocardial infarction (OR 1.44, 95% CI 1.32 to 1.57 top quintile vs. bottom quintile before adjustment), which was non-significant after adjustment for other risk factors (0.98, 0.88 to 1.09). For waist-to-hip ratio, the odds ratios for every successive quintile were significantly greater than that of the previous one (2nd quintile: 1.15, 1.05 to 1.26; 3rd quintile: 1.39; 1.28 to 1.52; 4th quintile: 1.90, 1.74 to 2.07; and 5th quintiles: 2.52, 2.31 to 2.74 [adjusted for age, sex, region, and smoking]). Waist-to-hip ratio and waist and hip circumferences were closely (p<0.0001) associated with risk of myocardial infarction even after adjustment for other risk factors. The relation between increasing hip circumference and AMI was inverse. The risk of AMI rose progressively with increasing values for wait-to-hip-ratio with no evidence of a threshold. Waist-to-hip-ratio is a predictor of myocardial infarction independant of BMI. The population-attributable risks of myocardial infarction for increased waist-to-hip ratio in the top two quintiles was 24.3% (95% CI 22.5 to 26.2) compared with only 7.7% (6.0 to 10.0) for the top two quintiles of BMI.
Comment: The quality of evidence was upgraded by dose-response relationship.
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