Objective: To explore the effect of breastfeeding duration on age at adiposity rebound, and provide a scientific theoretical basis for identifying early life factors of obesity in children and adolescents, while promoting early intervention. Methods: In September 2019, first graders from a primary school in Minhang District, Shanghai, were selected to participate in this study, and their growth information was retrospectively collected. The natural cubic spline function was used to fit the body mass index trajectory of the subjects from 1 to 80 months, and age at adiposity rebound was calculated. A total of 6 148 subjects were selected, and complete data of adiposity rebound timing and breastfeeding duration were obtained. A multiple linear regression model was used to analyze the relationship between these two variables. Results: The average breastfeeding duration of all children included in the study was (3.71±3.28) months, and most of the subjects (69.63% for male and 70.45% for female) were breastfed for less than 4 months. A positive linear relationship was found between them [male, B =0.16(0.02-0.30), female, B =0.34(0.18- 0.51 ), total, B =0.23(0.12-0.34), P <0.05]. The linear relationship was determined using the multivariate model. Conclusion Breastfeeding duration independently affected age at adiposity rebound. Prolonging the duration of breastfeeding within 24 months of age may help to delay the timing of adiposity rebound,and thus reduce later risks of overweight and obesity.

Objective: To explore the influence of birth weight and growth patterns during infancy on overweight and obesity among first grade primary school pupils, so as to provide a theoretical basis for the formulation of early life prevention and intervention policies. Methods: In 2019, data related to routine physical examinations were collected for primary school pupils in the Minhang District of Shanghai, and information regarding birth and follow ups was collected retrospectively. Physical examination data of 4 434 pupils at 12 months of age were obtained. A multiple linear regression model was used to analyze the relationship between growth patterns during infancy and body mass index (BMI) in the first grade of primary school. A generalized linear model was employed to analyze the relationship between birth weight and growth patterns during infancy and overweight and obesity in the first grade of primary school. A hierarchical analysis was conducted. Results: A linear relationship was observed between growth patterns during infancy and BMI and the BMI Z score of first grade primary school pupils [ β(β 95%CI)=0.30(0.24-0.35),0.12(0.10- 0.15 ), P <0.01]. In addition to subjects classified as small for gestational age (SGA), catch up growth during infancy was identified among subjects who were classified as appropriate for gestational age (AGA) and large for gestational age (LGA). LGA at birth and catch up growth during infancy were independent risk factors for overweight and obesity among first grade primary school children ( RR =1.31-1.55, P <0.05). The hierarchical analysis showed that catch up growth increased the risk of overweight and obesity among first grade primary school pupils classified as AGA [ RR(RR 95%CI )=1.74(1.42-2.14),1.87(1.56-2.26)], and increased the risk of obesity among first grade primary school pupils classified as SGA and LGA [ RR(RR 95%CI )=3.74(1.04-13.49),3.24(1.62-6.46)]( P <0.05). Among those who exhibited catch up growth during infancy, LGA increased the risk of obesity among first grade primary school pupils ( RR= 2.60 , 95%CI=1.35-5.02, P <0.01), but not the risk of being overweight ( P =0.13). Conclusion Birth weight and growth patterns during infancy have an impact on overweight and obesity among children in the first grade of primary school. It is suggested that attention should be paid to growth and physical development in early life for those classified as LGA and AGA, and catch up growth in children should be closely monitored.

Objective: To explore the characteristics of the adiposity peak and rebound in early life among first year primary school students with different body weight measures, so as to provide scientific evidence for the development of prevention interventions to manage childhood overweight and obesity. Methods: A total of 2 330 first year primary school students who received routine physical examinations from September to December in 2019 were selected. According to body mass index (BMI) status, participants were divided into three categories:healthy weight, overweight, and obese. The BMI growth trajectories of the three groups were fitted by gender using the generalized additive mixed model from 1 to 80 months, retrospectively. Each subject s age at the adiposity peak and rebound, and associated BMI values, were calculated. Results: The prevalence of overweight and obesity was 16.31 % (380/ 2 330 ) and 16.09% (375/2 330), respectively. For first year students with obesity, the BMI value continued to be higher than their overweight or healthy weight counterparts during the first 80 months of life. The age at the adiposity peak for these students, whose BMI status varied, was about nine months. However, the BMI of children with overweight or obesity was much higher than that of healthy weight subjects. Age at adiposity rebound was 72 months for healthy weight children, 52 to 55 months in children defined as overweight, and 22 to 23 months in children with obesity. For healthy weight children, the fitted value of BMI at the adiposity rebound was less than that of overweight and obese children. Conclusion Age at the adiposity peak was largely similar among first year students with different BMI patterns; however, age at adiposity rebound was different. Age at adiposity rebound among children with obesity was much earlier than that of other subjects, and their BMI values were much higher.

Objective: To investigate thyroid hormone concentration and associated factors among pubertal girls in Minhang District of Shanghai. Methods: From January to March 2019, a stratified sampling method was used to select junior high schools from the east, south, north, and middle areas in Minhang district. A total of 386 girls of grade 6 in selected schools were included in the study. Physical examination was conducted, and their urine and blood samples were collected to determine urinary iodine concentration (UIC) and thyroid function. Puberty Development Self-rating Scale (PDS) was used to define the pubertal stage. Logistic regression models were conducted to analyze the associations between pubertal stage and thyroid function. Results: The median urinary iodine concentration was 163.57(106.57, 232.96) μg/L. The geometric mean values of TSH, TT3, FT3 and FT4 were 0.29 mU/L, 0.26 nmol/L, 0.68 pmol/L and 1.18 pmol/L.The mean value of TT4 was 91.64 nmol / L. The abnormal rates of TGAb and TPOAb were 6.22% and 4.15%. The rate of abnormal TGAb combined with abnormal TPOAb was 3.68%. Girls in puberty and post-puberty had the lower level of TT4 (OR=0.47,0.43) as compared with girls in pre-puberty stage. Obese girls had higher level of TT3(OR=9.08, 95%CI=1.52-54.07). With the increase of exercise time(0.5-1, >1 h/d), FT4 level was increased (OR=2.45, 2.19). TSH levels were significantly higher in girls with higher TGAb and TPOAb. Girls had higher TT4 or FT4 levels if their TGAb levels were higher and TPOAb levels were normal. Conclusion There is an association between pubertal stage, obesity, exercise and thyroid function in school-aged girls during puberty in iodine sufficient areas. TSH, FT4 and TT4 levels are correlated with TGAb and TPOAb levels.

Objective: To observe the association between puberty development and thyroid function among school-aged girls in Minhang District of Shanghai, in order to explore the effect of puberty development on thyroid function. Methods: The study was based on a cohort of adolescent girls recruited in iodine-suitable areas of Minhang District, and the baseline and follow-up survey have been carried out from January to March 2019. The method of phased cluster sampling was used to select one junior high school in the east, south, north and middle of Minhang District, Shanghai, respectively. Finally, 464 new junior high school girls were included in the Cohort study for physical examination, and girls were followed up from January to March 2021. The Puberty Development Scale (PDS) was used to assess the stage of puberty. Serum thyroid stimulating hormone (TSH), free triiodothyronine (FT3), and free thyroxine (FT4) were determined for each participant. Thyroid homeostasis structure parameters (THSPs) was calculated. Changes of Thyroid hormones at baseline and follow-up were compared by Wilcoxon signed rank sum test. Multiple linear regression analyses were used to evaluate the associations of thyroid hormones (THs) and THSPs changes with pubertal develepment. Results: Serum TSH levels of female studentds decreased significantly, while their FT3 and FT4 levels increased significantly during the study period ( Z=-10.53, -4.71, -12.46, P <0.01). In multiple linear regression analysis after adjustment for co-variables (including baseline age, change of BMI and waist circumference), FT4 and thyroid feedback quantile-based index (TFQI) in the higher puberty category scores changes (△PCS) group were further reduced compared with those in the low △PCS group ( β =-0.66, -0.55 ). Compared to the late puberty at baseline and follow-up (BLFL) group, FT4 and TFQI showed higher decline in the pre-puberty at baseline and late puberty at follow-up (BPFL) group with the pre-puberty at baseline and end of puberty at follow-up (BPFT) group ( β =-0.55, -0.44)( P <0.05). There were no association of △TSH, △FT3, △FT4/FT3 and TSH index changes (△TSHI) with △PCS or the puberty pattern. Conclusion Serum TSH decreases while serum FT3 and FT4 increase among girls during puberty. Both the initial stage and the velocity of pubertal development are related to thyroid hormone fluctuations.

ObjectiveTo identify and analyze the possible influencing factors of obesity among public primary school students in Minhang District， Shanghai. MethodsBasic data， collected through questionnaire stars， was imported with merged physical examination data into Excel to form a database. Data were collected by questionnaire and analyzed by SPSS 22.00. Independent sample t-test was used for the data with normal distribution. Nonparametric test was used for the data with non-normal distribution. χ² test was used for the quantitative data. Logistic regression was used for univariate and multivariate analysis. ResultsAccording to the national physical health standards for students （revised in 2014） ， the prevalence rate of obesity among primary school students in Minhang district was 29.63% . The prevalence of overweight and obesity was 32.1% in boys and 26.9% in girls. The trend of overweight and obesity in different grades was similar among different genders .A single factor analysis showed that， being the only child （χ²=9.300， P<0.01） ， father obesity（χ²=106.417， P<0.001） or mother obesity（χ²=118.534， P<0.001） ， mother's overweight during pregnancy （χ²=159.731， P<0.001） ， caregiver's role as grandparents （χ²=38.736， P<0.001） ， low education level （χ²=111.309， P<0.001） had effects on overweight and obesity of children while the differences had statistical significance. Pupil's bad eating habit （χ²=18.905，P<0.001） and preference （χ²=22.901， P<0.001） ， insufficient sleep time （χ²=61.685， P<0.001） ， long-time using of electronic products （χ²=37.182， P<0.001） and low-time of exercise （χ²=15.328， P<0.001） also affected the obesity of primary school students. Among the five factors of family， diet， psychology， static state and dynamic state， the influencing factors of obesity in primary school students from grade one to grade four were being the only child， obese father and/or mother， overweight mother during pregnancy， caregivers without higher education. In terms of diet， it was mainly based on eating habits before bedtime， as well as partial and picky eating habits. In terms of psychology， the main psychological source was the pressure of learning in school. There was a clear relationship between the pace of learning and not keeping up. Static analysis revealed a correlation with lack of sleep. After assigning values based on eye hygiene recommendations for the use of electronic products， it was found that there was no direct correlation between obesity in primary school students and the duration of electronic product use. Dynamic analysis showed that not taking part in school physical exercise was related to obesity. ConclusionThe obesity of primary school students is influenced by family， diet， psychology， static and dynamic factors. The intervention of obesity in primary school needs the joint efforts of school， society， family， self-cognition and so on.

ObjectiveTo understand the visual environment sanitation in primary and secondary school classrooms in Minhang District， Shanghai， and to investigate the factors affecting the decline in students’ visual acuity. MethodsIn 2020， among all the primary and secondary schools in Minhang District， according to different types of classroom structures， levels， orientations， unilateral lighting， and bilateral lighting， a total of 20 231 students from 674 classrooms in primary and secondary schools were selected through stratified cluster sampling. Each monitored classroom was regarded as a research unit， and the naked eye vision of students was tested using a standard logarithmic vision chart during the 2020 and 2021 academic years. The change in average visual acuity between the two measurements was taken as the dependent variable， and the visual environment indices were considered as independent variables. The relationship between classroom visual environment indices and the decline in students’ naked eye vision was analyzed. ResultsThe qualification rates for per capita classroom area， window to floor area ratio， average illuminance of the blackboard， uniformity of blackboard illuminance， average illuminance of the desks， uniformity of desk illuminance， lighting coefficient of classroom， blackboard reflection ratio， back wall reflection ratio， and distance between lamps and desks were 79.53%， 88.58%， 46.74%， 70.33%，64.69%， 80.86%， 71.81%， 20.30%， 1.63%， and 97.53%， respectively. The average naked eye vision of primary and secondary school students in the 2020 academic year was 4.75±0.37 （right eye） and 4.76±0.37 （left eye）， while in the 2021 academic year， it was 4.70±0.39 （right eye） and 4.71±0.38 （left eye）. There was a significant decrease in the naked eye vision of primary and secondary school students in the 2021 academic year compared to that of 2020 （P<0.05）. Univariate linear regression analysis showed a significant correlation between grade， average illuminance of the blackboard， average illuminance of the desks， uniformity of desk illuminance， lighting coefficient， and distance between lamps and desks， and the decline of students’ naked eye vision within one academic year （P<0.05）. After adjusting for grade， multiple linear regression analysis revealed a significant correlation between the average illuminance of the blackboard， uniformity of desk illuminance， lighting coefficient， and distance between lamps and desks， and the decline of students’ naked eye vision within one academic year （P<0.05）. Higher average illuminance of the blackboard， uniformity of desk illuminance， lighting coefficient， and distance between lamps and desks were protective factors for naked eye vision. ConclusionThe visual environment of primary and secondary school classrooms in Minhang District is a matter of concern. Average illuminance of the blackboard， uniformity of desk illuminance， lighting coefficient， and distance between lamps and desks are related to the degree of visual impairment in students over a year.

ObjectiveTo investigate the general situation of defect of vertebral column among primary and middle school students in Minhang District of Shanghai and analyze the related factors， to provide a scientific basis for prevention and treatment. MethodsFrom September to October 2022， a total of 5 715 students were selected from two primary schools， two middle schools， and two high schools in Minhang District for physical examinations and screening for defect of vertebral column. ResultsTotally 219 students had defect of vertebral column， accounting for 3.83% of the sampled population. Anteroposterior spinal abnormalities were found in 4 individuals， accounting for 0.07%， and 218 students had scoliosis， accounting for 3.81%. The detection rate of defect of vertebral column was higher in girls （6.27%） than that in boys （1.51%）， and higher in high school students （10.74%） than in primary school students （1.31%） and middle school students （10.97%）. Students who are mildly underweight （5.95%） and who are moderately to severely underweight （7.46%） had a higher detection rate of defect of vertebral column than those with normal weight （4.54%）， overweight （2.83%）， and obesity （1.60%）. The detection rate among students with poor vision （4.32%） was significantly higher than those with normal vision （2.24%）， with all differences statistically significant （all P<0.05）. ConclusionThe positive rate of defect of vertebral column in primary and middle school students in Minhang District， Shanghai is nearly 4%， with most cases being scoliosis. Factors such as being female， increasing age， being underweight， and poor vision are associated with a higher probability of detecting defect of vertebral column.

Background The prevalence of malnutrition in older adults is high. Early use of appropriate screening scales for malnutrition risk and early intervention can effectively improve life quality of the elderly in communities. Objective To evaluate the risk of malnutrition among the community-dwelling elderly in a district of Shanghai and explore its influencing factors. Methods From October to December 2021, a total of 960 seniors aged 65 years and above in community committees (villages) of Minhang District were selected by stratified random sampling. Trained investigators conducted one-to-one interviews with included seniors using questionnaires. The questionnaires included the Geriatric Depression Scale (GDS), the Activity of Daily Living Scale (ADL), and the malnutrition risk assessment for elderly adults. Height, weight, waist circumference, and calf circumference were measured. Chi-square test and logistic regression were used to analyze potential influencing factors of malnutrition in the elderly. Results Among the 960 community-dwelling seniors of Minhang District, 13 (1.35%) were malnourished and 311 (32.40%) were at the risk of malnutrition. There were statistically significant differences in nutritional status across different categories of age, sex, monthly family income, education level, marital status, waist circumference, dental health status, activity of daily living, nutrition knowledge, suffering from chronic diseases, having > 3 chronic diseases, taking > 3 long-term prescriptions, depression symptoms, sleeping duration, daily outdoor activity time, number of daily food species (milk/soy products/fish/meat/poultry/eggs), daily intake of vegetables and fruits, daily consumption of cooking oil, frequency of physical exercise, frequency of smoking, and living alone (P < 0.05). The logistic regression analysis results showed that poor dental conditions, insufficient daily intake of milk/soy products/fish/meat/poultry/eggs (<3 kinds), insufficient daily intake of vegetables and fruits (<500 g), excessive daily consumption of cooking oil (>25 g), insufficient daily outdoor activities (<1 h·d⁻¹), living alone, low educational level (primary school and below), suffering from chronic diseases, having > 3 chronic diseases, taking > 3 long-term prescriptions, and being single/widowed/divorced were the main risk factors for nutritional abnormalities in the elderly (P< 0.05). Conclusion The elderly in Minhang District of Shanghai have a high malnutrition risk, and their nutritional status is affected by multiple factors, including poor dental status, irrational dietary structure, insufficient time for outdoor activities, suffering from chronic diseases, having > 3 chronic diseases, taking > 3 long-term prescriptions, low educational level, living alone, and being single/widowed/divorced.