Relationship between weight status and health-related quality of life in Chinese primary school children in Guangzhou: a cross-sectional study

Background: To investigate the association between weight status and health-related quality of life (HRQOL) among pupils in Guangzhou, China. Methods: The study comprised 5781 children aged 8-12 years from 29 schools. Height and weight were objectively measured using standardized methods, and BMI z-score derived using the age and sex specific WHO reference 2007 for 5-19 years. Weight status was classified as underweight (<-2SD), healthy weight (between -2SD and 1SD), overweight/obesity (> 1SD). HRQOL was measured by the self-report version of the Pediatric Quality of Life Inventory 4.0. Results: After controlling for gender, age, school type, parental education, and family income, HRQOL scores were significantly lower in overweight/obese compared with healthy weight children only in the social functioning domain (beta = -1.93, p = 0.001). Compared with healthy weight children, underweight children had significantly lower total (beta = -1.47, p = 0.05) and physical summary scores (beta = -2.18, p = 0.02). Subgroup analysis for gender indicated that compared to healthy weight, total (beta = -1.96, p = 0.02), psychosocial (beta = -2.40, p = 0.01), social functioning (beta = -3.36, p = 0.001), and school functioning (beta = -2.19, p = 0.03) scores were lower in overweight/obese girls, but not boys. On the other hand, being underweight was associated with lower physical functioning (beta = -2.27, p = 0. 047) in girls, and lower social functioning (beta = -3.63, p = 0.01) in boys. The associations were mainly observed in children aged 10 and over, but were not significant in younger children. Children from private schools had generally lower HRQOL compared to those in public schools, but the associations with weight status were similar in both groups. Conclusions: The relationship between overweight/obesity and HRQOL in children in China is not as prominent as that seen in children in western or high-income countries. However, there appears to be gender and age differences, with more of an impact of overweight on HRQOL in girls and older children compared with boys and younger children. Underweight is also associated with lower HRQOL. Future intervention to prevent both obesity and undernutrition may have a positive impact on the HRQOL in children in China.