American Journal of Epidemiology Advance Access originally published online on April 15, 2008
American Journal of Epidemiology 2008 167(12):1465-1475; doi:10.1093/aje/kwn079
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ORIGINAL CONTRIBUTIONS |
Waist Circumference and Mortality
1 Laboratory of Epidemiology, Demography, and Biometry, National Institute on Aging, Bethesda, MD
2 Faculty of Health, Medicine and Life Sciences, University of Maastricht, Maastricht, the Netherlands
3 Nutritional Epidemiology Branch, National Cancer Institute, Bethesda, MD
4 American Association of Retired Persons, Washington, DC
Correspondence to Dr. Annemarie Koster, National Institute on Aging, 7201 Wisconsin Avenue, Gateway Building, Suite 3C309, Bethesda, MD 20892 (e-mail: kostera{at}mail.nih.gov).
Received for publication October 4, 2007. Accepted for publication March 12, 2008.
The authors examined the association between waist circumference and mortality among 154,776 men and 90,757 women aged 51–72 years at baseline (1996–1997) in the NIH-AARP Diet and Health Study. Additionally, the combined effects of waist circumference and body mass index (BMI; weight (kg)/height (m)2) were examined. All-cause mortality was assessed over 9 years of follow-up (1996–2005). After adjustment for BMI and other covariates, a large waist circumference (fifth quintile vs. second) was associated with an approximately 25% increased mortality risk (men: hazard ratio (HR) = 1.22, 95% confidence interval (CI): 1.15, 1.29; women: HR = 1.28, 95% CI: 1.16, 1.41). The waist circumference-mortality association was found in persons with and without prevalent disease, in smokers and nonsmokers, and across different racial/ethnic groups (non-Hispanic Whites, non-Hispanic Blacks, Hispanics, and Asians). Compared with subjects with a combination of normal BMI (18.5–<25) and normal waist circumference, those in the normal-BMI group with a large waist circumference (men: 
102 cm; women: 88 cm) had an approximately 20% higher mortality risk (men: HR = 1.23, 95% CI: 1.08, 1.39; women: HR = 1.22, 95% CI: 1.09, 1.36). The finding that persons with a normal BMI but a large waist circumference had a higher mortality risk in this study suggests that increased waist circumference should be considered a risk factor for mortality, in addition to BMI.
abdominal fat; adiposity; body composition; body fat distribution; body mass index; mortality
Abbreviations: BMI, body mass index; CI, confidence interval; HR, hazard ratio