Objective To analyze the comorbidity rates of myopia, overweight and obesity, and spinal curvature abnormalities among primary and secondary school students in Chengdu in 2024, explore the influencing factors of comorbidity, and provide a scientific basis for developing comorbidity prevention and control strategies for common diseases in this population.

Methods A stratified cluster random sampling method was employed. Primary and secondary school students from 23 districts under the jurisdiction of Chengdu were randomly selected as study subjects in 2024. Physical examinations and questionnaire surveys were conducted to analyze the comorbidity rates of myopia, overweight and obesity, and spinal curvature abnormalities. The Chi-square test was used to analyze basic characteristics and related factors. A multivariate binary logistic regression model was employed to identify factors associated with comorbidity.

Results A total of 49612 students were included. The detection rate of comorbidity was 18.40%. Multivariate binary logistic regression showed that the risk of comorbidity in males was 1.256 times (95% CI: 1.194-1.322) that in female students.The risk in junior high school, general high school, and vocational high school students was 1.557 times (95% CI: 1.456-1.665), 1.823 times (95% CI: 1.684-1.974), and 1.869 times (95% CI: 1.666-2.097) that of primary school students, respectively. The risk for students engaging in ≥60 min/day of moderate-to-vigorous physical activity was 0.902 times (95% CI: 0.831-0.979) that of those with <60 min/day.The risk for students with insufficient sleep was 1.085 times (95% CI: 1.025-1.148) that of those with adequate sleep. The risk for students whose break-time activity area was outside the classroom but inside the teaching building and outdoors was 0.939 times (95% CI: 0.890-0.990) and 0.841 times (95% CI: 0.768-0.921) that of those staying inside the classroom, respectively.

Conclusion The detection rate of comorbidity is relatively high in Chengdu. Male students, junior high school students, general high school students, and vocational high school students are key populations for comorbidity prevention and control. It is recommended to strengthen health education and promote knowledge on the co-prevention of multiple diseases. Differentiated interventions should be implemented for these key populations, focusing on improving modifiable factors such as physical activity and sleep.