The independent effect of body mass index on health-related quality of life among racial and ethnic subgroups

To evaluate the impact of race/ethnicity on the relationship between body mass index (BMI) and health-related quality of life (HRQOL) among blacks, Hispanics, and whites. We used the Sinai Urban Health Institute's Improving Community Health Survey dataset to measure physical and mental HRQOL using the Physical Component Score (PCS-12) and the Mental Component Score (MCS-12) of the Short Form-12. Multivariate linear regression models were applied to the overall sample and in models stratified by race/ethnicity to evaluate the effects of BMI on physical and mental HRQOL outcome variables while controlling for confounders. Considering physical HRQOL, increasing BMI was independently associated with worse PCS-12 (beta = -0.22, p value < 0.001) in the overall sample; the magnitude was not significantly different across racial/ethnic subgroups (blacks: beta = -0.18, p value = 0.02; Hispanics: beta = -0.28, p value = 0.01; whites: beta = -0.20, p value = 0.02). Overall, Hispanic participants reported a worse PCS-12 compared to whites (beta = -3.06, p value = 0.002). Considering mental HRQOL, BMI was not significantly associated with MCS-12 in the overall sample (beta = -0.06, p value = 0.21) nor was BMI significantly associated with MCS-12 in any racial/ethnic subgroups. Overall, black participants reported better MCS-12 compared to whites (beta = 2.51, p value = 0.001). BMI was associated with worse physical HRQOL to a similar degree among blacks, Hispanics, and whites. This finding suggests that interventions leading to obesity reduction should be associated with substantial and equal improvements in the physical HRQOL of all race/ethnicity groups.