摘要：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. During the past 30 years the prevalence of obesity, defined as a body mass index (BMI, defined as weight in kilograms divided by the square of height in meters) of 30 or greater, increased in all racial or ethnic groups in the United States. Historically, obesity has been uncommon among Asian Americans compared with other racial or ethnic groups in the United States, but the prevalence of obesity in this population is rising. Between 1991 and 2008, the prevalence of obesity increased from 13.9% to 28.7% among US-born Asians and from 9.5% to 20.7% among Asian immigrants. 1 Substantial epidemiological data have defined the dose–response association between BMI and mortality among Whites in the United States, 2 and to a lesser degree among US Blacks. 3 However, data for Asian Americans, a fast-growing racial group in the United States, are sparse. 4 Recently, a pooled analysis among East Asians residing in Asia, including Chinese, Japanese, and Koreans, showed that the association between BMI and total mortality was nonlinear, in that BMIs greater than 25 and less than 22.6 were both associated with increased mortality. 5 It was interesting that the increased mortality associated with a high BMI in East Asians was not observed among Indians and Bangladeshis in Asia. 5 Asian Americans share an environment with US Whites and Blacks, which differs markedly from that of their counterparts in Asia. It is unclear whether this change in context results in different susceptibility to obesity and obesity-related diseases between Asian Americans and Asians residing in Asia, or whether a shared genetic background contributes to a similar association between obesity and disease. To investigate the association between BMI and risk of mortality among Asian Americans in the largest sample to date, we pooled data from 10 prospective cohort studies in the United States. 6–15
