[Epidemiological characteristics and related factors of multimorbidity of wasting and spinal curvature abnormalities among children and adolescents aged 6-18 years in Inner Mongolia Autonomous Region, China].

<b>Objective:</b> To analyze the epidemiological characteristics of wasting, spinal curvature abnormalities and multimorbidity among children and adolescents aged 6-18 in Inner Mongolia and explore the related factors of these two health problems. <b>Methods:</b> In September 2022, a stratified random cluster sampling method was employed to select 188 635 children and adolescents aged 6-18 in Inner Mongolia for physical examinations and questionnaire surveys. Data on height, weight, as well as dietary behavior, physical activity, classroom environment, academic tasks, writing posture, and screen behavior were collected. The epidemiological characteristics of wasting, spinal curvature abnormalities and multimorbidity were analyzed. Additionally, a multivariate logistic regression model was used to analyze the factors associated with wasting, spinal curvature abnormalities and multimorbidity. <b>Results:</b> A total of 188 635 children and adolescents aged 6-18 years participated in this study, including 95 393 boys (50.6%) with an average age of (11.53±3.32) years. The detection rate of wasting was 3.79%, with a higher detection rate in boys (4.18%) than in girls (3.38%) (<i>P</i><0.001). The detection rate of spinal curvature abnormalities was 3.64%, with a higher detection rate in girls (4.04%) than in boys (3.25%) (<i>P</i><0.001). The detection rate of multimorbidity between wasting and spinal curvature abnormalities was 0.17%, and there was no statistically significant difference between genders (<i>P</i>>0.05). The detection rates of wasting, spinal curvature abnormalities, and multimorbidity all increased with age (<i>P_t</i><0.001). The multivariate logistic regression analysis showed that, after adjusting for gender, age, urban/rural status, and school grade, compared to children and adolescents who exercised ≥1 hour of moderate-to-vigorous physical activity (MVPA) for at least 5 days per week and had daily screen time <2 hours, those who exercised <5 days per week (<i>O</i>R=1.28, 95%<i>CI</i>: 1.19-1.37) and had daily screen time ≥2 hours (<i>OR</i>=1.11, 95%<i>CI</i>: 1.03-1.19) had a higher risk of wasting. Compared to children and adolescents who had ≥5 physical education (PE) classes per week, adjusted desk and chair height,<1 hour of after-school study/writing time, and whose parents or teachers rarely or never reminded them about posture, those with <5 PE classes per week (<i>OR</i>=1.11, 95%<i>CI</i>: 1.02-1.21), unadjusted desk and chair height (<i>OR</i>=1.08, 95%<i>CI</i>: 1.01-1.15),≥1 hour of after-school study/writing time (<i>OR</i>=1.15, 95%<i>CI</i>: 1.07-1.24), frequent reminders from parents (<i>OR</i>=1.16, 95%<i>CI</i>: 1.09-1.23), and frequent reminders from teachers (<i>OR</i>=1.10, 95%<i>CI</i>: 1.04-1.16) had a higher risk of spinal curvature abnormalities. Compared to children and adolescents who did not consume sugary drinks daily, exercised ≥1 hour of MVPA for at least 5 days per week, and whose teachers rarely or never reminded them about posture, those who consumed sugary drinks daily (<i>OR</i>=1.61, 95%<i>CI</i>: 1.00-2.46), exercised <5 days per week (<i>OR</i>=1.33, 95%<i>CI</i>: 1.01-1.79), and had teachers who frequently reminded them about posture (<i>OR</i>=1.35, 95%<i>CI</i>: 1.05-1.75) had a higher risk of multimorbidity between wasting and spinal curvature abnormalities. <b>Conclusion:</b> The detection rates of wasting, spinal curvature abnormalities and multimorbidity among children and adolescents aged 6-18 in Inner Mongolia are generally low, with an increasing trend observed with age. Both lifestyle and school environmental factors are associated with wasting, spinal curvature abnormalities and multimorbidity.