BACKGROUND: The urban-rural disparities in overweight and obesity among children and adolescents are narrowing, and there is a need for long-term and updated data to explain this inequality, understand the underlying mechanisms, and identify priority groups for interventions. METHODS: We analyzed data from seven rounds of the Chinese National Survey on Students Constitution and Health (CNSSCH) conducted from 1985 to 2019, focusing on school-age children and adolescents aged 7-18 years. Joinpoint regression was used to identify inflection points (indicating a change in the trend) in the prevalence of overweight and obesity during the study period, stratified by urban/rural areas and sex. Annual percent change (APC), average annual percent change (AAPC), and 95% confidence interval (CI) were used to describe changes in the prevalence of overweight and obesity. Polynomial regression models were used to predict the prevalence of overweight and obesity among children and adolescents in 2025 and 2030, considering urban/rural areas, sex, and age groups. RESULTS: The prevalence of overweight and obesity in urban boys and girls showed an inflection point of 2000, with AAPC values of 10.09% (95% CI: 7.33-12.92%, t = 7.414, P <0.001) and 8.67% (95% CI: 6.10-11.30%, t = 6.809, P <0.001), respectively. The APC for urban boys decreased from 18.31% (95% CI: 4.72-33.67%, t = 5.926, P = 0.027) to 4.01% (95% CI: 1.33-6.75%, t = 6.486, P = 0.023), while the APC for urban girls decreased from 13.88% (95% CI: 1.82-27.38%, t = 4.994, P = 0.038) to 4.72% (95% CI: 1.43-8.12%, t = 6.215, P = 0.025). However, no inflection points were observed in the best-fit models for rural boys and girls during the period 1985-2019. The prevalence of overweight and obesity for both urban and rural boys is expected to converge at 35.76% by approximately 2027. A similar pattern is observed for urban and rural girls, with a prevalence of overweight and obesity reaching 20.86% in 2025. CONCLUSIONS The prevalence of overweight and obesity among Chinese children and adolescents has been steadily increasing from 1985 to 2019. A complete reversal in urban-rural prevalence is expected by 2027, with a higher prevalence of overweight and obesity in rural areas. Urgent action is needed to address health inequities and increase investments, particularly policies targeting rural children and adolescents.
Humans ; Child ; Adolescent ; Female ; Male ; Rural Population/statistics & numerical data* ; Overweight/epidemiology* ; Prevalence ; China/epidemiology* ; Pediatric Obesity/epidemiology* ; Obesity/epidemiology* ; Urban Population

Objective:To describe the body mass index (BMI) level and long-term trends of Chinese older adults aged 65 and above.Methods:Older adults aged 65 and above from six waves (2002-2018) of the China Longitudinal Healthy Longevity Survey were selected as the study population. Multiple cross-sectional design with six survey waves conducted in 2002, 2005, 2008, 2011, 2014, and 2018 was adopted, enrolling 15 647, 15 358, 15 622, 9 166, 6 302, and 12 417 participants, respectively. Additionally, a total of 13, 755 participants were included in the cohort study design. Relevant information was collected through questionnaires and physical examinations. The χ2 trend test was used to compare the changes in the rates of underweight and overweight/obesity over the years, and the linear mixed-e?ects model (LMM) was used to fit trajectory curves of BMI changes with advancing age in older adults. Results:The baseline ages of the participants included in 2002, 2005, 2008, 2011, 2014, and 2018 were (85.16±11.26), (84.23±11.83), (84.99±12.16), (81.10±11.86), (78.89±11.30), and (83.08±12.42) years, respectively, with a relatively high proportion of females and rural residents. In the cohort study, the 13 755 participants had a median ( Q1, Q3) follow-up time of 6.5 (5.2, 10.0) years, with a cumulative follow-up duration of 109 041 person-years. In each wave, males had higher BMI than females, urban residents had higher BMI than rural residents, and BMI gradually decreased with increasing age (all P<0.001). The mean BMI of older adults in China increased from (19.37±3.80) kg/m2 in 2002 to (22.04±4.01) kg/m2 in 2018 ( P<0.001). Across all survey years, the prevalence of underweight was consistently higher in women than in men and in rural areas than in urban areas, with an upward trend as age increased (all P<0.001). In 2018, the underweight rates in the 65-79, 80-89, 90-99, and ≥100-year-old age groups were 8.0%, 16.7%, 26.2%, and 35.5%, respectively. Meanwhile, the prevalence of overweight/obesity was higher in men than in women and in urban areas than in rural areas, showing a declining trend with advancing age (all P<0.001). The prevalence of underweight among the older adults decreased significantly from 45.2% in 2002 to 18.9% in 2018 ( P<0.001), while the prevalence of overweight/obesity increased from 11.0% in 1998 to 29.6% in 2018 ( P<0.001). The trajectory curves fitted by the LMM model showed that individuals born in later decades had higher BMI levels at the same age compared to earlier cohorts. Conclusion:From 2002 to 2018, the BMI level among Chinese older adults showed an increasing trend. The prevalence of underweight showed a declining trend, while the rates of obesity and overweight increased. However, the underweight rate remained notably high among the oldest old.

Objective:To develop outcome indicators for the implementation of comprehensive inter-ventions targeting the multimorbidity of myopia and obesity in children and adolescents,providing a basis for the co-prevention of multimorbidity and the outcome measurement of implementation research in children and adolescents.Methods:Based on the RE-AIM framework,a preliminary set of indicators was constructed.The Delphi method was employed,with experts scoring and providing feedback on the proposed indicators via questionnaires.After each round of consultation,expert enthusiasm index,authority coefficient,coordination degree,and consensus level were calculated.Expert opinions were col-lected and analyzed to modify,delete,or add indicators based on consultation results and screening crite-ria.Two Delphi rounds were conducted until consensus was achieved.Results:A total of 28 experts par-ticipated actually in both rounds.The Kendall's W coefficients for the two rounds of expert consultation were0.352(x2=413.952,P＜0.001)and 0.499(x2=405.044,P＜0.001),both statistically sig-nificant.The final outcome indicators for implementation research on comprehensive interventions for myopia and obesity comorbidity in children and adolescents included five primary dimensions with 13 secondary and 20 tertiary indicators.The dimension of reach included the number of children and adoles-cents involved,participant representativeness,and full-course participation representativeness.The di-mension of effectiveness included multimorbidity incidence,myopia incidence,spherical equivalent,body mass index(BMI),overweight and obesity prevalence,waist-to-height ratio,comprehensive health knowledge score,and comprehensive health behavior score.The dimension of adoption covered school representativeness and representativeness of school nurses and teachers involved in implementation.The dimension of implementation included fidelity,content modification,and cost.The dimension of mainte-nance included individual health outcomes and organizational sustainment.Conclusion:This study developed implementation outcome indicators for comprehensive interventions targeting multimorbidity of myopia and obesity among the children and adolescents based on the RE-AIM framework.These indica-tors can serve as a reference for optimizing intervention research strategies related to common multimor-bidity among children and adolescents in China.

Objective:To describe the body mass index (BMI) level and long-term trends of Chinese older adults aged 65 and above.Methods:Older adults aged 65 and above from six waves (2002-2018) of the China Longitudinal Healthy Longevity Survey were selected as the study population. Multiple cross-sectional design with six survey waves conducted in 2002, 2005, 2008, 2011, 2014, and 2018 was adopted, enrolling 15 647, 15 358, 15 622, 9 166, 6 302, and 12 417 participants, respectively. Additionally, a total of 13, 755 participants were included in the cohort study design. Relevant information was collected through questionnaires and physical examinations. The χ2 trend test was used to compare the changes in the rates of underweight and overweight/obesity over the years, and the linear mixed-e?ects model (LMM) was used to fit trajectory curves of BMI changes with advancing age in older adults. Results:The baseline ages of the participants included in 2002, 2005, 2008, 2011, 2014, and 2018 were (85.16±11.26), (84.23±11.83), (84.99±12.16), (81.10±11.86), (78.89±11.30), and (83.08±12.42) years, respectively, with a relatively high proportion of females and rural residents. In the cohort study, the 13 755 participants had a median ( Q1, Q3) follow-up time of 6.5 (5.2, 10.0) years, with a cumulative follow-up duration of 109 041 person-years. In each wave, males had higher BMI than females, urban residents had higher BMI than rural residents, and BMI gradually decreased with increasing age (all P<0.001). The mean BMI of older adults in China increased from (19.37±3.80) kg/m2 in 2002 to (22.04±4.01) kg/m2 in 2018 ( P<0.001). Across all survey years, the prevalence of underweight was consistently higher in women than in men and in rural areas than in urban areas, with an upward trend as age increased (all P<0.001). In 2018, the underweight rates in the 65-79, 80-89, 90-99, and ≥100-year-old age groups were 8.0%, 16.7%, 26.2%, and 35.5%, respectively. Meanwhile, the prevalence of overweight/obesity was higher in men than in women and in urban areas than in rural areas, showing a declining trend with advancing age (all P<0.001). The prevalence of underweight among the older adults decreased significantly from 45.2% in 2002 to 18.9% in 2018 ( P<0.001), while the prevalence of overweight/obesity increased from 11.0% in 1998 to 29.6% in 2018 ( P<0.001). The trajectory curves fitted by the LMM model showed that individuals born in later decades had higher BMI levels at the same age compared to earlier cohorts. Conclusion:From 2002 to 2018, the BMI level among Chinese older adults showed an increasing trend. The prevalence of underweight showed a declining trend, while the rates of obesity and overweight increased. However, the underweight rate remained notably high among the oldest old.

Objective:To develop outcome indicators for the implementation of comprehensive inter-ventions targeting the multimorbidity of myopia and obesity in children and adolescents,providing a basis for the co-prevention of multimorbidity and the outcome measurement of implementation research in children and adolescents.Methods:Based on the RE-AIM framework,a preliminary set of indicators was constructed.The Delphi method was employed,with experts scoring and providing feedback on the proposed indicators via questionnaires.After each round of consultation,expert enthusiasm index,authority coefficient,coordination degree,and consensus level were calculated.Expert opinions were col-lected and analyzed to modify,delete,or add indicators based on consultation results and screening crite-ria.Two Delphi rounds were conducted until consensus was achieved.Results:A total of 28 experts par-ticipated actually in both rounds.The Kendall's W coefficients for the two rounds of expert consultation were0.352(x2=413.952,P＜0.001)and 0.499(x2=405.044,P＜0.001),both statistically sig-nificant.The final outcome indicators for implementation research on comprehensive interventions for myopia and obesity comorbidity in children and adolescents included five primary dimensions with 13 secondary and 20 tertiary indicators.The dimension of reach included the number of children and adoles-cents involved,participant representativeness,and full-course participation representativeness.The di-mension of effectiveness included multimorbidity incidence,myopia incidence,spherical equivalent,body mass index(BMI),overweight and obesity prevalence,waist-to-height ratio,comprehensive health knowledge score,and comprehensive health behavior score.The dimension of adoption covered school representativeness and representativeness of school nurses and teachers involved in implementation.The dimension of implementation included fidelity,content modification,and cost.The dimension of mainte-nance included individual health outcomes and organizational sustainment.Conclusion:This study developed implementation outcome indicators for comprehensive interventions targeting multimorbidity of myopia and obesity among the children and adolescents based on the RE-AIM framework.These indica-tors can serve as a reference for optimizing intervention research strategies related to common multimor-bidity among children and adolescents in China.

Objective: To analyze the prevalence of comorbidity of spinal curvature abnormality and malnutrition among primary and secondary school students aged 10-18 years in Tianjin in 2023, so as to provide scientific basis for the combined prevention of common diseases and multiple diseases among students and the construction of school health system. Methods: In September to October 2023, 31 884 primary and secondary school students aged 10 to 18 years in Tianjin were selected using stratified cluster random sampling. Abnormal spinal curvature in children and adolescents was assessed by Sereening of Spinal Curvature Abnormality of Children and Adolescents, while stunting, wasting, overweight, and obesity were determined according to the Screening for Malnutrition among Schoolage Children and Adolescents and Screening for Overweight and Obesity among Schoolage Children and Adolescents. The χ2 test was used to compare betweengroup differences in coprevalence, and multiple Logistic regression models were used to analyze the risk of different comorbidity types in different clusters. Results: The coprevalence of spinal curvature abnormality and malnutrition among primary and secondary school students in Tianjin was 1.6%, which was higher for girls than boys (1.8%, 1.4%), higher (2.5%) for senior high schools than for junior high schools and elementary schools (2.0%, 0.5%), and higher in rural than in urban areas (2.1%, 1.1%) (χ2=9.45, 141.92, 46.94, P<0.05). Multiple Logistic regression models showed that junior high school girls had a higher risk of incorrect posture comorbid with stunting and wasting (OR=4.52, 95%CI=1.84-11.06) and incorrect posture comorbid with overweight and obesity (OR=2.67, 95%CI=1.74-4.10) than boys, and that scoliosis/sagittal spinal abnormality comorbid with stunting and wasting (OR=0.10, 95%CI=0.02-0.44) risk was lower than that of boys, senior high school girls had a lower risk of scoliosis/sagittal spinal abnormality comorbid with overweight and obesity (OR=0.27, 95%CI=0.11-0.66) (P<0.05). Conclusions The coprevalence of spinal curvature abnormality and malnutrition is specific among primary and secondary school students in Tianjin, and the comorbidity type varies by gender and education stage. There is a need to increase prevention and control of spinal curvature abnormalities in school health working, intensive screening of key populations, and timely intervention.

The technology of three-dimensional(3D)printing emerged in the late 1970s and has since undergone considerable development to find numerous applications in mechanical engineering,industrial design,and biomedicine.In biomedical science,several studies have initially found that 3D printing technology can play an important role in the treatment of diseases in hepatopancreatobiliary surgery.For example,3D printing technology has been applied to create detailed anatomical models of disease organs for preoperative personalized surgical strategies,surgical simulation,intraoperative navigation,medical training,and patient education.Moreover,cancer models have been created using 3D printing technology for the research and selection of chemotherapy drugs.With the aim to clarify the development and application of 3D printing technology in hepatopancreatobiliary surgery,we introduce seven common types of 3D printing technology and review the status of research and application of 3D printing technology in the field of hepatopancreatobiliary surgery.

Objective:To investigate the association of urinary cadmium levels with peripheral leukocyte classification counts among middle-aged and older adults aged 40 to 89 years in selected areas of China.Methods:The research was based on the survey of the impact of soil quality of agricultural land on human health in typical areas conducted in 2019-2020. A total of 5 600 middle-aged and older adults aged 40 to 89 years were included by using a multi-stage stratified random sampling method. Baseline characteristics of the subjects were collected and physical examinations were performed. Random midstream urine was collected to measure urinary cadmium and urinary creatinine and fasting venous blood was collected to measure the leukocyte count, neutrophil count, lymphocyte count, monocyte count and eosinophil count. The linear mixed effect model was used to analyse the association of urinary cadmium levels with leukocyte classification counts, and the dose-response relationship between them was analyzed by using the restricted cubic spline (RCS) function.Results:The age of the subjects was (63.17±12.02) years; 2 851 (50.91%) were males; and the M ( Q 1, Q 3) of urinary creatinine-corrected urinary cadmium levels was 2.69 (1.52, 4.69) μg/g·creatinine. After adjusting for confounding factors, the results of linear mixed effects model analysis showed that for each 1-unit increase in urinary creatinine-corrected urinary cadmium level, the percentage change [% (95% CI)] of leukocyte count and lymphocyte count was -1.70% (-2.61%, -0.79%) and -1.57% (-2.86%, -0.26%), respectively. RCS function showed a negative linear relationship between urinary creatinine-corrected urinary cadmium levels and leukocyte counts and lymphocyte counts, respectively (all Pnon-linear>0.05). Conclusion:Urinary cadmium levels are negatively associated with leukocyte count and lymphocyte count among middle-aged and older adults aged 40 to 89 years in selected areas of China.

Objective:To describe the current distribution of daily physical activity time among ele-mentary and junior high school students in Beijing,and to analyze the influencing factors and pathways at the individual,family,school and community levels.Methods:Data were drawn upon from a cross-sectional investigation in Beijing in 2023,and a total of 3 157 elementary and junior high school students were included in the final analysis.Questionnaire was used to collect data on basic characteristics,over-all and in-school physical activity time per day,the number of sports mastered,perceived physical activi-ty benefits and barriers scales,perceived family,school,and community physical activity supportive en-vironment scales.Log-binomial regression model was used to analyze the associations between physical activity time and influencing factors,and structural equation modeling was used for the path analysis of the influencing factors.Results:The reported rates of ≥ 2 hours of overall physical activity per day and≥1 hour of physical activity in school per day among elementary and junior high school students in Beijing in 2023 were 33.1％and 64.8％,respectively.The associations between the number of sports mastered by students and the reported rate of ≥2 hours of overall physical activity per day showed a typical dose-response relationship(P-trend＜0.001).The perceived physical activity benefits-to-barriers ratio(PR=1.24,95％CI:1.20-1.28),scores of perceived family,school,and community physical acti-vity supportive environment scales were all positively associated with the reported rate of≥2 hours of overall physical activity per day(PR=1.51,95％CI:1.38-1.66;PR=1.50,95％CI:1.37-1.64;PR=1.21,95％CI:1.16-1.27).The structural equation modeling showed that the number of sports mastered by the students(β=0.11,P＜0.001),perceived physical activity benefits-to-barriers ratios(β=0.15,P＜0.001),and scores of supportive environment scales consisting of family,school,and community(β=0.13,P＜0.001)were associated with the reported rates of ≥2 hours of overall physi-cal activity per day directly.In addition,the scores of supportive environment scales could indirectly in-fluence the reported rates of ≥2 hours of overall physical activity per day by influencing the number of sports mastered by the students(β=0.21,P＜0.001)and the perceived physical activity benefits-to-barriers ratio(β=0.56,P＜0.001),while the number of sports mastered by the students could indi-rectly influence the reported rates of ≥2 hours of overall physical activity per day by influencing the per-ceived physical activity benefits-to-barriers ratios(β=0.05,P=0.003).The influencing factors and pathways of the reported rates of ≥ 1 hour of physical activity in school per day were similar with those of the reported rates of ≥2 hours of overall physical activity per day described above.Conclusion:The dai-ly physical activity time among elementary and junior high school students in Beijing in 2023 fell short of meeting the national requirement.There was a need to build a supportive environment consisting of fami-ly,school,and community for physical activity,to promote the students'sports skills,to establish the idea of independent physical activity,and to ensure that primary and secondary school students were given one hour of physical activity time every day,both inside and outside the school.

Objective:To investigate the association of urinary cadmium levels with peripheral leukocyte classification counts among middle-aged and older adults aged 40 to 89 years in selected areas of China.Methods:The research was based on the survey of the impact of soil quality of agricultural land on human health in typical areas conducted in 2019-2020. A total of 5 600 middle-aged and older adults aged 40 to 89 years were included by using a multi-stage stratified random sampling method. Baseline characteristics of the subjects were collected and physical examinations were performed. Random midstream urine was collected to measure urinary cadmium and urinary creatinine and fasting venous blood was collected to measure the leukocyte count, neutrophil count, lymphocyte count, monocyte count and eosinophil count. The linear mixed effect model was used to analyse the association of urinary cadmium levels with leukocyte classification counts, and the dose-response relationship between them was analyzed by using the restricted cubic spline (RCS) function.Results:The age of the subjects was (63.17±12.02) years; 2 851 (50.91%) were males; and the M ( Q 1, Q 3) of urinary creatinine-corrected urinary cadmium levels was 2.69 (1.52, 4.69) μg/g·creatinine. After adjusting for confounding factors, the results of linear mixed effects model analysis showed that for each 1-unit increase in urinary creatinine-corrected urinary cadmium level, the percentage change [% (95% CI)] of leukocyte count and lymphocyte count was -1.70% (-2.61%, -0.79%) and -1.57% (-2.86%, -0.26%), respectively. RCS function showed a negative linear relationship between urinary creatinine-corrected urinary cadmium levels and leukocyte counts and lymphocyte counts, respectively (all Pnon-linear>0.05). Conclusion:Urinary cadmium levels are negatively associated with leukocyte count and lymphocyte count among middle-aged and older adults aged 40 to 89 years in selected areas of China.