Abstract P370: Obesity and Incident Coronary Heart Disease in the Million Women Study: A Prospective, Population-based Cohort Study
Background: Higher body-mass index (BMI) has been associated with increased risk for coronary heart disease (CHD) mortality but its association with incident CHD is less investigated, and data for women are limited.
Methods: We examined the prospective relation between BMI and incident CHD (first CHD hospitalization or death) in 1.2 million women aged ≥50 years without prior CHD, who were recruited through a national breast screening programme in 1996 to 2001 and followed for an average of 9 years (48,842 events with 10.7 million person-years of follow-up). Absolute and relative risks (using Cox regression) associated with higher BMI were estimated.
Results: After excluding the first 4 years of follow-up, there were 32,465 events (5.9 million person-years) including 3,345 CHD deaths. The adjusted relative risk per 5 kg/m2 BMI difference was 1.24 [95% confidence interval (CI) 1.22 to 1.25]. CHD risk increased linearly across a wide range of BMI, with no apparent excess risk in the lower end of BMI distribution. The relation persisted after excluding current smokers or limiting cases to myocardial infarction only. For women in this cohort, the 20-year cumulative risk of CHD from age 55 to 74 years (95% CI) ranged from 9% (8 to10) to 18% (16 to 20) for women with BMI of 20 to 22.5 kg/m2 and ≥35 kg/m2, respectively. Never smokers with BMI ≥35 kg/m2 had comparable cumulative risk to current smokers with BMI of 20 to 22.5 kg/m2.
Conclusion: In this large cohort of women, the impact of excess weight on CHD morbidity and mortality is substantial. Measures to prevent and control excess weight and other CHD risk factors are needed to help reduce CHD burden in women.
- © 2012 by American Heart Association, Inc.