Abstract
Introduction: Prior studies have found a U-shaped association between body mass index (BMI) and mortality. The WHO has recommended Asian-specific BMI guidelines to better screen for BMI-related diseases among Asians. Little is known about patterns between BMI and mortality rates in Asian subgroups. We used Asian-specific BMI cutpoints to determine whether BMI was associated with mortality among disaggregated Asian subgroups.
Methods: A sample of Asians (n=26,831) was obtained from the 1999-2018 National Health Interview Survey (NHIS) linked to the National Death Index. BMI was calculated with self-reported height and weight. Individuals were grouped into 4 BMI classes by Asian-specific BMI cutpoints: underweight (BMI <18.5), normal (BMI >18.5-22.9), overweight (BMI > 23-24.9), and obese (BMI ≥ 25) categories. Using Poisson models, we calculated the age-standardized mortality rate (ASMR) per 1,000 person years (PY) for All Asian adults and specific sub-groups (Asian Indian, Chinese, Filipino, Other Asian) with normal weight as a reference.
Results: Our sample was comprised of 20.6% Chinese (n=5517), 22.8% Filipino (n=6111), 19.5% Asian Indian (n=5232), and 37.2% Other Asian (n=9971). Compared to normal BMI, underweight individuals had significantly higher ASMR among all Asians and more specifically among Chinese, Filipinos, and Asian Indians, but not among Other Asians. Compared to normal BMI, risk of mortality was not significantly different among overweight or obese individuals across any Asian subgroup.
Conclusion: We found that low BMI was consistently associated with increased mortality among all Asian subgroups. In contrast to what has been described in Non-Hispanic White adults, we found that overweight or obesity was not associated with increased mortality among Asian American subgroups utilizing Asian-specific cutpoints.