The relationship between body mass index and health-related quality of life in the adult Chinese population: among the healthy and chronic disease subgroups

Abstract

Objective To investigate the relationship between body mass index (BMI) and health-related quality of life (HRQOL) in the adult Chinese population. Methods Data of 21 108 adults was collected from a cross-sectional survey performed in 9 provinces of China (Jiangsu, Anhui, Gansu, Qinghai, Fujian, Beijing, Jilin, Jiangxi and Henan province). Rank sum test was used to compare HRQOL with different BMI category. Multiple logistic regression analysis was used to assess the impact of different BMI category on HRQOL after adjusted for sex, age, marital, education, physical activity status, and tobacco and alcohol addiction. Results (1) For healthy subjects, the overweight BMI group had the highest HRQOL score in the physical component summary (PCS)(83.69±14.09) and mental component summary(MCS)(80.29±15.41), while the underweight group had the worst HRQOL(81.20±14.05, 74.82±16.41). For subjects with chronic condition, overweight had the highest HRQOL score in the PCS(74.63±18.51), and obese group had the best HRQOL in the MCS(76.75±18.83). The variation among healthy and chronic disease subjects was much greater than the differences among BMI category groups. (2) Compared with normal weight, data on odds ratio(ORs) of impaired HRQOL in PCS(healthy subjects OR=1.23(1.10-1.35), chronic disease subjects OR=1.48(1.20-1.82)) MCS(healthy subjects OR=1.14(1.03-1.26), chronic disease subjects OR=1.37(1.11-1.68)) and multiple dimensions increased among underweight.ORs of impaired HRQOL in PCS and general health dimension, MCS(healthy subjects OR=0.81(0.72-0.91), chronic disease subjects OR=0.80(0.71-0.91)) and multiple dimensions decreased among overweight. ORs of impaired HRQOL in physical functioning dimension (healthy subjects OR=1.91(1.25-2.92), chronic disease subjects OR=1.65(1.21-2.26)) while in MCS and role emotional and mental health dimension decreased among obese. Conclusion Whatever health or chronic disease, the influence of BMI on HRQOL is similar: the HRQOL score for the underweight group is significantly lower than that for other BMI groups in PCS and MCS.Overweight and the obese people has better HRQOL in MCS, and the obese people has poor physical function.The relation above between BMI and HRQOL is more obvious in people with chronic disease. Key words: Body mass index; Health-related quality of life; Chronic disease