Ethnic specific obesity cut-offs for diabetes risk: Cross-sectional study of 489,690 UK Biobank participants
Obesity cut-offs may not be appropriate for use in non-White populations due to ethnic differences in the association between obesity and diabetes. We aimed to derive ethnic specific cut-offs for a number of anthropometric measures based on equivalent risk of diabetes.
METHODS:
UK Biobank recruited 502,682 UK residents aged 40-69 years. We used baseline data on the 491,741 participants from the four largest ethnic sub-groups: 472,287 (96.4%) White, 8,040 (1.6%) Black, 5,952 (1.2%), 8,040 (1.6%) South Asian, and 1,574 (0.3%) Chinese. For each ethnic group, regression models were developed for the association between anthropometric measures (body mass index, waist circumference and waist-hip ratio) and prevalent diabetes, stratified by sex and adjusted for age, physical activity, socioeconomic status and heart disease.
RESULTS:
Non-White participants were two–to four– fold more likely to have diabetes. In terms of diabetes prevalence, a body mass index of 30 kg/m2 among White participants equated to 20 kg/m2 in South Asians, 25 kg/m2 in Blacks and 25 kg/m2in Chinese participants. Among women, a waist circumference of 88 cm in the White sub-group equated to 69 cm in the South Asian, 78 cm in the Black and 77 cm in the Chinese sub-groups. Among men, a waist circumference of 102 cm in White participants, equated to 76 cm, 85 cm and 81 cm for South Asian, Black and Chinese participants, respectively.
CONCLUSIONS: Obesity should be defined at lower thresholds in non-White populations to ensure that interventions are targeted equitably based on equivalent diabetes prevalence. Furthermore, within the Asian population, a substantially lower obesity threshold should be applied to South Asian compared with Chinese groups.