• Yikyung Park, Cari M. Kitahara, Steven C. Moore, Amy Berrington de Gonzalez, D. Michal Freedman, Robert N. Hoover, Martha S. Linet, Mark Purdue, Catherine Schairer, and Patricia Hartge are with the Division of Cancer Epidemiology and Genetics, National Cancer Institute, Bethesda, MD. Sophia Wang and Leslie Bernstein are with the Division of Cancer Etiology, Department of Population Sciences, Beckman Research Institute and the City of Hope, Duarte, CA. Ellen T. Chang is with Health Sciences Practice, Exponent Inc, Menlo Park, CA. Alan J. Flint and Walter C. Willett are with the Department of Nutrition, Harvard School of Public Health, Boston, MA. J. Michael Gaziano, Howard D. Sesso, and Walter C. Willett are with the Division of Preventive Medicine, Harvard Medical School, Brigham and Women's Hospital, Boston, MA. Kim Robien is with Departments of Epidemiology and Biostatistics and Exercise Science, School of Public Health and Health Services, George Washington University, Washington, DC. Emily White is with the Cancer Prevention Program, Fred Hutchinson Cancer Research Center, Department of Epidemiology, University of Washington, Seattle. Bradley J. Willcox is with the Pacific Health Research and Education Institute and Queen's Medical Center, Honolulu, HI. Michael J. Thun is with the Department of Epidemiology, Epidemiology and Surveillance Research, American Cancer Society, Atlanta, GA.

OBJECTIVES: We investigated the association between body mass index (BMI) and mortality among Asian Americans.

METHODS: We pooled data from prospective cohort studies with 20 672 Asian American adults with no baseline cancer or heart disease history. We estimated hazard ratios and 95% confidence intervals (CIs) with Cox proportional hazards models.

RESULTS: A high, but not low, BMI was associated with increased risk of total mortality among individuals aged 35 to 69 years. The BMI was not related to total mortality among individuals aged 70 years and older. With a BMI 22.5 to < 25 as the reference category among never-smokers aged 35 to 69 years, the hazard ratios for total mortality were 0.83 (95% CI = 0.47, 1.47) for BMI 15 to < 18.5; 0.91 (95% CI = 0.62, 1.32) for BMI 18.5 to < 20; 1.08 (95% CI = 0.86, 1.36) for BMI 20 to < 22.5; 1.14 (95% CI = 0.90, 1.44) for BMI 25 to < 27.5; 1.13 (95% CI = 0.79, 1.62) for BMI 27.5 to < 30; 1.82 (95% CI = 1.25, 2.64) for BMI 30 to < 35; and 2.09 (95% CI = 1.06, 4.11) for BMI 35 to 50. Higher BMI was also related to increased cardiovascular disease and cancer mortality.

CONCLUSIONS: High BMI is associated with increased mortality risk among Asian Americans.