The association between body mass index and health-related quality of life: influence of ethnicity on this relationship

Aims The association between obesity and a poorer health-related quality of life (HRQL) has previously been explored. The influence of ethnicity on this relationship has less frequently been considered. We aimed to explore the relationship between body mass index (BMI) and HRQL in a mixed population of White European (WE) and South Asian (SA) ethnicity. Methods Cross-sectional data were analysed (n=4989, 16% SA) from a population-based diabetes screening study. BMI categories were based on ethnic-specific cut-points. HRQL was categorized low (<0.848) or high (0.848) according to the median EQ5D score. Logistic regression was used to examine the relationship between BMI and HRQL. Interaction analysis was conducted to determine the effect of ethnicity. Results Overweight (OR=1.22, 95% CI: 1.101.41, p<0.001) and obese people (OR=1.81, 95% CI: 1.562.10, p<0.001) had increased odds of having a low HRQL compared to normal weight people. After adjusting for potential confounders, age, gender, ethnicity, deprivation score, fruit and vegetable intake, physical activity, cardiovascular disease, chronic kidney disease and smoking, this association was strengthened further. However, for obese people, SA ethnicity significantly reduced the risk of having a low HRQL when compared to WEs (adjusted OR=0.58, 95% CI: 0.340.97). Conclusions Our findings provide further evidence of an association between increasing BMI and low HRQL but suggest that SA ethnicity modifies this relationship. These results could have important health implications and are a basis for further research.