Association between Body-Mass Index and Risk of Death in More Than 1 Million Asians

Abstract

Background Most studies that have evaluated the association between the body-mass index (BMI) and the risks of death from any cause and from specific causes have been conducted in populations of European origin. Methods We performed pooled analyses to evaluate the association between BMI and the risk of death among more than 1.1 million persons recruited in 19 cohorts in Asia. The analyses included approximately 120,700 deaths that occurred during a mean follow-up period of 9.2 years. Cox regression models were used to adjust for confounding factors. Results In the cohorts of East Asians, including Chinese, Japanese, and Koreans, the lowest risk of death was seen among persons with a BMI (the weight in kilograms divided by the square of the height in meters) in the range of 22.6 to 27.5. The risk was elevated among persons with BMI levels either higher or lower than that range — by a factor of up to 1.5 among those with a BMI of more than 35.0 and by a factor of 2.8 among those with a BMI of 15.0 or less. A similar U-shaped association was seen between BMI and the risks of death from cancer, from cardiovascular diseases, and from other causes. In the cohorts comprising Indians and Bangladeshis, the risks of death from any cause and from causes other than cancer or cardiovascular disease were increased among persons with a BMI of 20.0 or less, as compared with those with a BMI of 22.6 to 25.0, whereas there was no excess risk of either death from any cause or cause-specific death associated with a high BMI. Conclusions Underweight was associated with a substantially increased risk of death in all Asian populations. The excess risk of death associated with a high BMI, however, was seen among East Asians but not among Indians and Bangladeshis.

The Association of Duration of Residence in the United States with Cardiovascular Disease Risk Factors Among South Asian Immigrants

“…More recent immigrants were also less likely to be overweight/obese than more settled South Asians (OR = 0.59 for 5 to \10 years; 95 % CI 0.35, 0.98). Results were unchanged in sensitivity analyses with different cut-points for BMI [60][61][62][63][64]. We found that South Asian immigrants who were overweight/obese had 2.32 greater odds (95 % CI 1.11, 4.86) of reporting diabetes and 2.19 greater odds (95 % CI 1.34, 3.56) of reporting hypertension than those with a healthy BMI.…”

The association of religiosity with overweight/obese body mass index among Asian Indian immigrants in California

“…Some researchers have suggested lower BMI cut-offs for Asians, with overweight as BMI ≥ 23 kg/m 2 and obese as BMI ≥ 25 or 27.5 kg/m 2 , though a recent study found no mortality differences among Asians at these lower BMI cut-offs (Misra and Khurana, 2011;World Health Organization expert consultation, 2004;Zheng et al, 2011). We found the association of overweight/obesity status with religiosity and other covariates to be similar across different BMI classifications and regardless of whether BMI was treated as a continuous variable or categorical variable (BMI ≥ 23 kg/m 2 vs. 18.5 ≤ BMI b 23 kg/m 2 or BMI ≥ 30 kg/m 2 vs. 18.5 ≤ BMI b 30 kg/m 2 ).…”

Trajectory of body shape in early and middle life and all cause and cause specific mortality: results from two prospective US cohort studies

“…6 7 A recent meta-analysis of 97 studies using standard BMI categories reported that relative to normal weight (BMI 18.5-<25), all cause mortality was increased for obesity (BMI ≥30) but was decreased for overweight (BMI 25-29) 8. These data are far from conclusive owing to methodological limitations, particularly reverse causation by pre-existing illness and confounding by smoking, which may have contributed to the inverse association between overweight and mortality 9…”