Weight Status and Myopia in Children and Adolescents: A Nationwide Cross-Sectional Study of China

Background/Objectives: The prevalence of both myopia and obesity is increasing among children and adolescents around the world. We aimed to examine the association between weight status and myopia in Chinese children and adolescents. Methods: The analysis included 35,108 participants aged 6-17 from a nationwide cross-sectional survey. Results: Our results indicated that girls with overweight and obesity had higher odds ratio (OR) of myopia and mild myopia: ages 6-8 (OR = 1.33, 95% CI: 1.01-1.76; OR = 1.71, 95% CI: 1.14-2.55) and 9-11 (OR = 1.22, 95% CI: 1.03-1.44; OR = 1.31, 95% CI: 1.06-1.62). Myopic boys had higher body fat percentages (BFP) at ages 6-8 (beta = 1.18, 95% CI: 0.38-1.98), 9-11 (beta = 0.58, 95% CI: 0.08-1.07), and 15-17 (beta = 0.42, 95% CI: 0.03-0.80), and higher body mass index (BMI) at ages 9-11 (beta = 0.30, 95% CI: 0.12-0.48) and 12-14 (beta = 0.19, 95% CI: 0.02-0.38). Girls had higher BFP at ages 9-11 (beta = 0.62, 95% CI: 0.19-1.05) and 12-14 (beta =0.53, 95% CI: 0.19-0.88) and higher BMI at 9-11 (beta = 0.53, 95% CI: 0.34-0.73). Furthermore, the dose-response curves revealed a significant gender- and age-specific association between BMI, BFP, and myopia odds ratio. Conclusions: the study found an association between overweight or obesity and myopia in girls aged 6-11, and indicated that high BFP and BMI are associated with myopia, varying by sex and age.