Elsevier

The Lancet

Volume 366, Issue 9497, 5–11 November 2005, Pages 1640-1649
The Lancet

Articles
Obesity and the risk of myocardial infarction in 27 000 participants from 52 countries: a case-control study

https://doi.org/10.1016/S0140-6736(05)67663-5Get rights and content

Summary

Background

Obesity is a major risk factor for cardiovascular disease, but the most predictive measure for different ethnic populations is not clear. We aimed to assess whether markers of obesity, especially waist-to-hip ratio, would be stronger indicators of myocardial infarction than body-mass index (BMI), the conventional measure.

Methods

We did a standardised case-control study of acute myocardial infarction with 27 098 participants in 52 countries (12 461 cases and 14 637 controls) representing several major ethnic groups. We assessed the relation between BMI, waist and hip circumferences, and waist-to-hip ratio to myocardial infarction overall and for each group.

Findings

BMI showed a modest and graded association with myocardial infarction (OR 1·44, 95% CI 1·32–1·57 top quintile vs bottom quintile before adjustment), which was substantially reduced after adjustment for waist-to-hip ratio (1·12, 1·03–1·22), and non-significant after adjustment for other risk factors (0·98, 0·88–1·09). 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, 1·05–1·26; 3rd quintile: 1·39; 1·28–1·52; 4th quintile: 1·90, 1·74–2·07; and 5th quintiles: 2·52, 2·31–2·74 [adjusted for age, sex, region, and smoking]). Waist (adjusted OR 1·77; 1·59–1·97) and hip (0·73; 0·66–0·80) circumferences were both highly significant after adjustment for BMI (p<0·0001 top vs bottom quintiles). 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 (ORs for top quintile vs lowest quintiles were 1·75, 1·33, and 0·76, respectively). The population-attributable risks of myocardial infarction for increased waist-to-hip ratio in the top two quintiles was 24·3% (95% CI 22·5–26·2) compared with only 7·7% (6·0–10·0) for the top two quintiles of BMI.

Interpretation

Waist-to-hip ratio shows a graded and highly significant association with myocardial infarction risk worldwide. Redefinition of obesity based on waist-to-hip ratio instead of BMI increases the estimate of myocardial infarction attributable to obesity in most ethnic groups.

Introduction

Obesity increases the risk of cardiovascular diseases and diabetes,1, 2 but these data are derived mainly from high-income countries. Although most of the global burden of cardiovascular disease is in developing countries, few data are available for the effect of obesity in these populations.3 Further, we do not know the measure of obesity (body-mass index [BMI], waist or hip circumferences, or waist-to-hip ratio) that shows the strongest relation to the risk of such disease and whether these measures are similar across different ethnic groups, in men and women, and at different ages.4 Previous studies provided conflicting results, possibly because of the modest number of cardiovascular events (a few hundred).5, 6, 7, 8, 9

On the basis of two previous smaller studies,10, 11 we had postulated that markers of central obesity (especially the waist-to-hip ratio) would be more strongly related to the risk of myocardial infarction than BMI (the conventional measure). We aimed to investigate the relation of BMI, waist and hip circumferences, and waist-to-hip ratio to the risk of myocardial infarction using data from the INTERHEART study,12, 13 of about 15 000 cases and a similar number of controls representing many ethnic groups.

Section snippets

Participants

We did a standardised case-control study of 15 152 cases of first myocardial infarction, and 14 820 age-matched and sex-matched controls. Details have been published previously.5 Consecutive cases of first myocardial infarction presenting within 24 h of symptom onset were eligible. All consenting cases without cardiogenic shock or history of major chronic diseases were included. At least one age-matched (±5 years) and sex-matched control (without a history of cardiovascular disease) was

Results

A total of 27 098 participants (12 461 cases and 14 637 age-matched and sex-matched controls) were included in these analyses. The distribution of various risk factors between cases and controls has been reported previously5 (webtable 1); here we focus only on measures related to obesity. There was no significant difference in height between cases and controls. The mean BMI in controls was 25·8 kg/m2, (95% CI; 25·8–25·9); 25·6 kg/m2 (25·5–25·7) in men and 26·5 kg/m2 (26·4–26·7) in women (

Discussion

The INTERHEART study clearly indicates that of the various anthropometric measures commonly used, waist-to-hip ratio shows the strongest relation with the risk of myocardial infarction worldwide. This ratio was the strongest anthropometric predictor of myocardial infarction in men and women, across all age and ethnic groups, in smokers and in non-smokers (potential effect modifier), and in those with or without dyslipidaemia, diabetes, or hypertension (which are consequences of obesity). By

References (34)

  • Appropriate body-mass index for Asian populations and its implications for policy and intervention strategies

    Lancet

    (2004)
  • I Baik et al.

    Adiposity and mortality in men

    Am J Epidemiol

    (2000)
  • ME Widlansky et al.

    Body Mass Index and total and cardiovascular mortality in men with a history of cardiovascular disease

    Arch Intern Med

    (2004)
  • KM Rexode et al.

    Abdominal adiposity and coronary heart disease in women

    JAMA

    (1998)
  • KM Rexrode et al.

    Abdominal and total adiposity and risk of coronary heart disease in men

    Int J Obes Relat Metab Disord

    (2001)
  • N Breslow et al.

    Statistical methods in cancer research, vol 1: the analysis of case-control studies

    (1980)
  • J Benichou et al.

    Variance calculations and confidence intervals for estimates of the attributable risk based on logistic models

    Biometrics

    (1990)
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