Meeting the Canadian 24-Hour Movement Guidelines and physical–mental comorbidity among Chinese children and adolescents: Prevalence, associations, and the population impacts

To examine the association between meeting the Canadian 24-Hour Movement Guidelines and physical–mental comorbidity among children and adolescents in a cross-sectional study. A total of 21,061 students aged 11–17 years from Zhejiang Province, China was recruited in the study. We examined the coexistence of five specific physical illnesses - hypertension, high myopia, dental caries, scoliosis, and obesity - with mental illness, specifically depressive symptoms. Generalized linear mixed models were performed to assess the association between overall and specific combinations of movement guidelines and physical–mental comorbidity, presented by odds ratio (OR) and 95% confidence interval (CI). Population attributable fraction (PAF) was calculated to estimate the preventable proportion of comorbid cases via meeting all three movement recommendations. Of the included participants, 19.3% had physical–mental comorbidity. There were 3.8% and 17.0% meeting all three and none of the recommendations, respectively. Meeting at least one recommendation, except for moderate-to-vigorous physical activity recommendation only, was associated with a lower risk of physical–mental comorbidity, with ORs (95% CIs) ranging from 0.72 (0.66–0.79) to 0.40 (0.31–0.51). Meeting more recommendations was associated with decreased comorbid risks, and the association was stronger in 4th–6th graders. The association between specific combinations of recommendations and comorbid risks showed differences by gender and grade. Of the comorbid cases, 42.1% were attributed to not adhering to all three recommendations, and the PAFs varied from 27.4% to 55.7% across different genders and grades. Adherence to the 24-h movement guidelines was associated with lower risks of physical–mental comorbidity among children and adolescents.