Author + information
- Received September 28, 2009
- Revision received December 14, 2009
- Accepted December 17, 2009
- Published online May 25, 2010.
- Andrew Mente, PhD⁎,†,
- Salim Yusuf, MBBS, DPhil⁎,†,
- Shofiqul Islam, MS⁎,
- Matthew J. McQueen, MBChB, PhD⁎,‡,
- Supachai Tanomsup, MD§,
- Churchill L. Onen, MD∥,
- Sumathy Rangarajan, MS⁎,
- Hertzel C. Gerstein, MD, MS⁎,†,
- Sonia S. Anand, MD, PhD⁎,†,⁎ (, )
- INTERHEART Investigators
- ↵⁎Reprint requests and correspondence:
Dr. Sonia S. Anand, David Braley Cardiac, Vascular and Stroke Research Institute, Hamilton General Hospital Campus, 237 Barton Street East, Room C3-102, Hamilton, Ontario L8L 2X2, Canada
Objectives This study examines the risk of acute myocardial infarction (MI) conferred by the metabolic syndrome (MS) and its individual factors in multiple ethnic populations.
Background The risk of the MS on MI has not been well characterized, especially in multiple ethnic groups.
Methods Participants in the INTERHEART study (n = 26,903) involving 52 countries were classified using the World Health Organization (WHO) and International Diabetes Federation (IDF) criteria for MS, and their odds ratios (ORs) for MI were compared with the individual MS component factors.
Results The MS is associated with an increased risk of MI, both using the WHO (OR: 2.69; 95% confidence interval [CI]: 2.45 to 2.95) and IDF (OR: 2.20; 95% CI: 2.03 to 2.38) definitions, with corresponding population attributable risks of 14.5% (95% CI: 12.7% to 16.3%) and 16.8% (95% CI: 14.8% to 18.8%), respectively. The associations are directionally similar across all regions and ethnic groups. Using the WHO definition, the association with MI by the MS is similar to that of diabetes mellitus (OR: 2.72; 95% CI: 2.53 to 2.92) and hypertension (OR: 2.60; 95% CI: 2.46 to 2.76), and significantly stronger than that of the other component risk factors. The clustering of ≥3 risk factors with subthreshold values is associated with an increased risk of MI (OR: 1.50; 95% CI: 1.24 to 1.81) compared with having component factors with “normal” values. The IDF definition showed similar results.
Conclusions In this large-scale, multi-ethnic, international investigation, the risk of MS on MI is generally comparable to that conferred by some, but not all, of its component risk factors. The characterization of risk factors, especially continuous variables, as dichotomous will underestimate risk and decrease the magnitude of association between MS and MI.
This study was supported by the Canadian Institutes of Health Research, the Heart and Stroke Foundationof Ontario, the International Clinical Epidemiology Network, and unrestricted grants from several pharmaceutical companies (with major contributions from AstraZeneca, Novartis, Hoechst Marion Roussel [now Aventis], Knoll Pharmaceuticals [now Abbott], Bristol-Myers Squibb, and Sanofi-Synthélabo), and various national bodies in different countries. Dr. Mente is supported by a Heart and Stroke Foundationof Canada Postdoctoral Research Fellowship. Dr. Yusuf is supported by an endowed chair of the Heart and Stroke Foundation of Ontarioand a Senior Scientist Award from the Canadian Institutes of Health Research. Dr. Anand holds the Michael G. DeGroote Heart and Stroke Foundation of Ontario Chair in Population Health Researchand the Eli Lilly Canada/May Cohen Chair in Women's Health.
- Received September 28, 2009.
- Revision received December 14, 2009.
- Accepted December 17, 2009.
- American College of Cardiology Foundation