Objective: To analyze the changes in the prevalence characteristics of multimorbidity among adolescents aged 13-18 in Inner Mongolia from 2019 to 2022 and to explore the association between multimorbidity and moderate to high-intensity physical activity among them. Methods: A stratified random cluster sampling method was used to select students aged 13-18 in Inner Mongolia every September from 2019 to 2022. Physical examinations, demographic characteristics, and depression-related surveys were conducted to analyze the multimorbidity of overweight, obesity, high blood pressure, myopia, spinal curvature abnormality, and depression. A logistic regression model was used to analyze the association between multimorbidity and moderate to high-intensity physical activity. Results: From 2019 to 2022, 70 972, 62 923, 80 254, and 78 288 study subjects were included, with the rates of multimorbidity being 56.4%, 55.4%, 57.2%, and 55.8%, respectively. The rates of multimorbidity remained relatively stable from 2019 to 2022 (χ2=0.06, P=0.950). The incidence of multimorbidity among girls was significantly higher than that among boys (P<0.001). The incidence of multimorbidity among urban students was significantly higher than that among suburban students (P<0.001). The incidence of multimorbidity among high school students was higher than that among middle school students (P<0.001). The top three multimorbidity combinations were myopia and overweight/obesity (26.4%), myopia and high blood pressure (24.4%), and myopia and depression (19.8%), while the least common combination was depression and spinal curvature abnormality (1.1%). The multimorbidity patterns showed no significant differences between years (χ2=0.03, P=0.999). The multimorbidity status was significantly associated with the status of meeting the standard of moderate to high-intensity physical activity (OR=0.83, 95%CI: 0.80-0.86). The association was stronger in boys (OR=0.77, 95%CI: 0.73-0.81) compared with girls (OR=0.90, 95%CI: 0.85-0.96), with a significant interaction term (P<0.001). Conclusion: From 2019 to 2022, the incidence of multimorbidity among adolescents aged 13 to 18 in Inner Mongolia is relatively high, mainly due to the co-occurrence of myopia and other health problems. Adequate physical activity is an important factor in reducing multimorbidity.
目的： 分析2019—2022年内蒙古13~18岁青少年多病流行特征变化，探讨青少年多病与中高强度身体活动的关联。 方法： 采用分层随机整群抽样方法，于2019—2022年每年9月选取内蒙古13~18岁学生，对其进行体格检查和人口学特征、抑郁状况相关的调查，分析超重肥胖、血压偏高、近视、脊柱弯曲异常和抑郁的多病状况，采用logistic回归模型分析中高强度身体活动与多病的关联。 结果： 2019—2022年分别纳入70 972、62 923、80 254和78 288名研究对象，其2种及以上多病患病率分别为56.4%、55.4%、57.2%、55.8%，多病患病率在2019—2022年变化较平稳（χ2=0.06，P=0.950）。女生多病患病率高于男生（均P<0.001）；城区学生多病患病率高于郊县，（均P<0.001）；高中生多病患病率高于初中生（均P<0.001）。两两共患组合模式占比较高的为近视和超重肥胖（26.4%）、近视和血压偏高（24.4%）、近视和抑郁（19.8%），较低的为抑郁和脊柱弯曲异常（1.1%）。两两共患组合患病率分布在年份间差异无统计学意义（χ2=0.03，P=0.999）。多病均与中高强度身体活动达标情况有显著关联（OR=0.83，95%CI：0.80~0.86）；与女生（OR=0.90，95%CI：0.85~0.96）相比，男生（OR=0.77，95%CI：0.73~0.81）多病与中高强度身体活动关联更强，交互项显著（P交互<0.001）。 结论： 2019—2022年内蒙古地区13~18岁青少年多病患病率较高，主要为近视与其他健康问题共患。充足的身体活动是减少多病的重要因素。.