Objective:To explore the relations among screen-based sedentary behaviors ( SSB) , family factors and body mass index ( BMI) of children, and to study how family factors have effect on BMI through influencing SSB. Methods:A total of 1 846 students aged 7-11 years from 12 primary schools in one district of Beijing were included. Their body weight and height were measured to calculate the BMI. The time of SSB and family factors were investigated by using questionnaires. The time of SSB was the total time of watching TV and videos, playing computer games and iPad each day during the past 7 days recalled by children. The family factors included the parents’ education, occupation, the parents’ time of SSB, whether the parents told their child the harm of SSB, the parents’ time limit for the children’ s SSB. The parents’ education and occupation were used for calculating the family socioeconomic score. Results:The median time of SSB for children was 1 hour/day, and the interquartile range was 1 hour/day. The BMI of the children with the parents’ time limit for the children’ s SSB less than 120 min/day were smaller than the children with the parents’ time limit not less than 120 min/day, in both the boys (1. 63 kg/m2,P<0. 001) and the girls (0. 85 kg/m2, P=0. 004). The family socioeconomic score, the parents’ SSB time, whether the parents told their children the harm of SSB were not related to the children’ s BMI . The mediation effects of SSB time for children on the association between the parents’ time limit for the children’s SSB and BMI were-0. 222 kg/m2(95%CI:-0. 432, -0. 095) for boys and-0. 187 kg/m2 (95%CI: -0. 507, -0. 049) for girls , which accounted for 13. 67% of the total effects for boys and 22. 11% for girls. Conclusion:The parents’ time limit for the children’ s SSB has effect on their BMI through influencing their SSB time. Parents’ supervision on the behaviors of children produces larger benefit for BMI than health education conveyed by parents. Therefore, parents’ participation in su-pervising the behaviors of children are indispensable for preventing and controlling childhood obesity.

Objective To retrospectively study the quantitative features and diagnostic value of 3-dimensional shear wave elastography (3D-SWE) in breast lesions.Methods A total of 198 consecutive women with 198 breast lesions (125 malignant,73 benign) were included,who underwent conventional ultrasound (US) and 3D-SWE before surgical excision.Quantitative parameters of transverse planes,sagittal planes and coronal planes were calculated,including maximum elasticity (Emax-w),mean elasticity (Emean-w),standard deviation (Esd) of the whole lesion and ratio between the stiffest elasticity (Emean-s)in the lesion and the fatty tissue (Eratio).Area under ROC curve(AUC) for combination of quantitative parameters and US were calculated.Results The AUC,sensitivity and specificity for US were 0.919,88.0％ and 78.1 ％,respectively.In the total 198 lesions,Emax-w,Emean-w,Esd,Eratio and Emean s were significantly lower in coronal planes than those in transverse and sagittal planes (all P ＜0.001).AUC for combination of each quantitative parameter and US were significantly higher than those of US (all P ＜0.05),except Emean-w of transverse plane,while there was no significant difference among the three orthogonal plane (P＞0.05).Sensitivity significantly increased by combining US with Emean-s,Eratio (transverse,sagittal and coronal planes),Emean-w (coronal and sagittal planes) or Esd (coronal and transverse planes) (all P＜0.05).Combination of US and Emean w of coronal plane yielded significantly higher sensitivity than those of transverse and sagittal planes.Conclusions Combination of quantitative features of 3D-SWE and US can significantly increase diagnostic accuracy and sensitivity in breast lesions.Emean-w of coronal plane yields the highest sensitivity.

Objective To retrospectively study the anisotropy of shear wave elastography (SWE)quantitative parameters of breast lesions,and the correlation with histopathology.Methods A total of 281 consecutive women with 281 breast lesions (179 malignant,102 benign) were included,who underwent conventional ultrasound (US) and 2D SWE before surgical excision.Three acquisitions each for transverse and longitudinal planes were obtained,and maximum elasticity (Emax),mean elasticity (Emean),standard deviation (Esd) of the whole lesion and ratio between the elasticity in the mass and the fatty tissue (Eratio)were recorded.Anisotropic difference (AD) and anisotropy factors (AF) were calculated,and correlation with histopathology was analyzed.Results The average Emax,Emean and Esd of transverse planes were significantly higher than those of longitudinal planes.AF showed positive correlation with quantitative elasticity (Emax,Emean,Esd and Eratio) (P =0.000),and was significantly higher in malignant lesions than that in benign besions (P =0.000).AUC of AF was significantly higher than that of AD (P ＜0.001).AF was significantly higher in invasive ductal carcinoma than that in ductal carcinoma in situ.Higher AF was associated with higher histopathological grades of invasive ductal carcinoma (P =0.000),and correlated with ER/PR(+).Conclusions Anisotropy of SWE is an indicator of malignancy of breast lesions,and is of predictive value for prognosis in breast cancer.

Objective To investigate the value of ultrasound-guided diffuse optical tomography (US-guided DOT) to predict clinical efficacy of breast cancer neoadjuvant chemotherapy (NAC).Methods Eighty-eight breast cancer patients with 93 lesions were included.Pre-and post-last chemotherapy,the size,total hemoglobin concentration (THC) of each lesion were measured by ultrasonography (US) and US-guided DOT.Based on the guidelines to evaluate the response to treatment in solid tumors,the lesions of treated breast cancer patients were divided into 4 types of responses to NAC:complete response (CR),partial response (PR),stable disease (SD),and progressive disease (PD).Efficient groups include CR and PR groups.Results As expected,no significant difference was found in size and THC for untreated lesions (all P ＞0.05).However,for the treated lesions(P =0.001),THC,pre-vs post-treatment size changes (△Size％) (P =0.002) and THC changes (△THC％) (P ＜0.001) were significantly varied among CR,PR,SD,PD groups.When compared with pre-treated,tumor sizes after treatment were changed significantly in all CR(P ＜0.001),PR(P ＜0.001),SD (P =0.023) and PD (P =0.001),while significant change of THC was only found in CR(P ＜0.001),PR(P ＜0.001) and SD (P =0.002).When △THC％ =23.9％ as the threshold for prediction of NAC efficiency,the area under the curve of ROC was 0.75,and the sensitivity was 73.7％,specificity was 76.5 ％,positive predictive value was 93.3 ％,negative predictive value was 39.4％,accuracy was 74.2％.Conclusions △size％ changes in consistent with △THC％ among the intergroups,but their changes levels are different,the highest change percent appears in CR,gradually decreased in PR,SD groups.△THC％ will contribute to predict preoperative clinical NAC efficacy.

Objective To investigate the influence of breast pure mucinous carcinoma size on sonographic characteristics and diagnostic accuracy.Methods Sonographic characteristics of 101 breast pure mucinous carcinoma in 1 00 patients were analyzed retrospectively.All lesions were divided into three groups according to maximum diameter at ultrasound.These were group Ⅰ with lesions less than 20 mm,group Ⅱwith lesions greater than or equal 20 mm,less than 40 mm,and group Ⅲ with lesions greater than or equal 40 mm.The relationship between lesions size and ultrasound parameters were analyzed.Results There were 38 lesions in group Ⅰ,52 lesions in group Ⅱ and 1 1 lesions in group Ⅲ.The patients age in group Ⅲwere older than that in group Ⅰ(F=3.442,P =0.036).Among these sonographic appearances,only shape (χ2=9.813,P =0.005)and blood flow (χ2=27.952,P =0.000)indicated significant differences.The accuracy of ultrasound diagnosis of breast cancer was 85.1%,the smaller the lesions were,the higher misdiagnosis rate the lesions were.Conclusions With lesions size increased,the lobular and internal blood flow of pure mucinous carcinoma increased.More smaller the lesions were,more higher misdiagnosis rate of lesions were.

Objective: To evaluate the effectiveness of a comprehensive intervention for childhood obesity on self-efficacy, weight perception, and stage of behavior change, and to provide a scientific evidence for childhood obesity interventions. Methods: The study was a cluster randomized controlled trial. Twelve primary schools and 1 889 children (aged 7-11 years) from Dongcheng District in Beijing were recruited in September, 2013, and were administered a comprehensive intervention for childhood obesity. Six schools (930) were randomly allocated to the intervention group, and six schools (959) were randomly allocated to the control group. A face-to-face questionnaire survey was carried out, R 4.0.3 software was used to analyze the data, and multiple linear regression model was used to analyze the intervention effect. Results: After the intervention, mean (standard deviation) scores of self-efficacy among children in the intervention and control groups were (4.4±0.9) and (4.2±1.1), respectively. After the intervention, the proportion of children in the intervention group who underestimated or overestimated their body weight was 28.4% and 11.3 %, respectively, while the figures in the control were 37.1% and 6.9%; compared with the control, the risk of underestimating body weight decreased among children in the intervention group( OR=0.64, 95%CI=0.52-0.80, P <0.01), while the risk of weight overestimation increased( OR=1.79, 95%CI=1.26-2.54, P <0.01). After the intervention, the proportion of children in the contemplation or action stage of behaviour change was 65.3% and 83.6%, while the figures in the control group were 59.8% and 69.8 %, respectively; in comparison with the control group, more children in the intervention group were in comtemplation ( OR= 1.28 , 95%CI=1.03-1.59, P =0.02) or action stage of behaviour change( OR=2.59, 95%CI=2.04-3.27, P <0.01). Conclusion The comprehensive intervention for childhood obesity improved self-efficacy, weight perception, and facilitated behavior change, but may increase the risk of weight overestimation.

Objective: To evaluate the effect of a dietary and exercise intervention on cognition and behaviors among primary school students, and to further explore the mediating role of family support, in order to provide scientific evidence for future effective intervention strategies. Methods: A dietary and exercise intervention program for childhood obesity prevention was carried out in 24 primary schools in Beijing, Changzhi and Urumqi from 2018 to 2019, and 1 392 children in grade four as well as their parents were included. Family support and children s cognition and behaviors were collected through questionnaire. To carry out diet and exercise behavior intervention on the three levels of school, family and individual in the intervention group,and children s dietary and exercise knowledge, eating habits, physical activities, as well as sedentary and screen behaviors were evaluated. The linear mixed model was used to analyze the effect of intervention on children s cognition and behaviors, and the mediation model was used to explore the role of family support. Results: The proportion of children with higher score of dietary and exercise knowledge ( OR= 2.34 , 95%CI =1.71-3.21), eating habits ( OR=2.58, 95%CI =1.75-3.82), and sedentary and screen behaviors ( OR=1.91, 95%CI =1.35-2.68) increased in the intervention group after one year intervention ( P <0.01), compared with the control group, respectively. The intervention also increased the proportion of children s family support in the intervention group compared with the control group ( OR=3.45, 95%CI =2.19-5.45), and the support from children s fathers ( OR=2.70, 95%CI =1.68-4.35), mothers ( OR=3.71, 95%CI =2.28-6.04), paternal grandmothers ( OR=1.65, 95%CI =1.00-2.70), and maternal grandmothers ( OR= 2.14, 95%CI =2.12-2.16) increased significantly ( P <0.05). The mediation analysis showed that family support played a mediating role in association between comprehensive intervention and children s eating habits as well as sedentary and screen behaviors. Conclusion The dietary and exercise intervention effectively promoted children s cognition and behaviors, and family support played an important mediating role.

Objective: To evaluate the cost effectiveness of a school based comprehensive intervention for childhood obesity and to provide scientific basis for formulating and promoting efficient and economic intervention measures for childhood obesity. Methods: In a cluster randomized controlled trial, 12 primary schools (1 889 students from grade 3 to 5) in Dongcheng District in Beijing were selected and randomly assigned to the intervention (6 schools, 930 students) and control group (6 schools, 959 students). Students in the intervention group received a one year school based comprehensive intervention for childhood obesity, including development of school level policies, health education activities, improvement of physical activity, and improvement of healthy diet. A cost analysis method from a social perspective was used to evaluate the implementation costs of the intervention. Cost effectiveness analysis was used by calculating incremental cost effectiveness ratio (ICER) on obesity related knowledge, number of days completing no less than 60 minutes of moderate to vigorous physical activity (MVPA) per week, students consuming sugar sweetened beverage. Results: The material cost and human cost were 46 376.24 yuan and 46 197.32 yuan, respectively. The total cost of the intervention was 92 573.56 yuan and the average cost was 99.54 yuan per student in the intervention group. ICER on obesity related knowledge, number of days completing no less than 60 minutes of MVPA per week, percentage of students consuming sugar sweetened beverage were 52.39%, 71.61% and 2.26%, respectively. Conclusion The school based comprehensive intervention for childhood obesity shows a good cost effectiveness promoting students obesity related knowledge, as well as dietary and physical activity behaviors.

Objective:To assess the predictive values of bioelectrical impedance analysis(BIA)-measured body fat indices to abnormal lipid profiles, and to preliminary propose optimal cut-off values of body fat in children and adolescents.Methods:Children and adolescents, aged 6-16 years, were selected from 30 schools (8 primary schools, 21 middle schools and one 12-year education school) in Dongcheng, Tongzhou, Fangshan and Miyun districts of Beijing by adopting a stratified cluster sampling method from November 2017 to January 2018.Questionnaire survey, body mass index(BMI), body fat mass index (FMI), fat mass percentage (FMP) and four lipid profiles were conducted.Results:A total of 14 309 participants, aged (11.0±3.3) years, were enrolled in the analysis, with 49.9% boys.In boys and girls, the percentile values ( P60- P95) fitted by FMI and FMP with K-median-coefficient of variation(LMS) method were taken as the cutting points, and P75 values were selected as the cut-off points of excessive body fat for their better sensitivity, specificity, predictive value and area under curve (AUC) for identification of abnormal lipid profiles.Boys with FMI above P75 accounted for 28% of the total population, and controlling boys with FMI below P75 could prevent dyslipidemia of 8%-57%.FMI in girl population occupied about 26% of the above, and controlling FMI in girl population below this cut-off point may prevent dyslipidemia from 8%-42%.FMP observed similar results to FMI.Assessed by FMI or FMP with P75 cut-off values, adiposity performed better than BMI for recognizing abnormal lipid profiles in boys (AUC: 52.4%-69.6% vs.50.2%-67.1%, P<0.05) rather than in girls ( P>0.05). In addition, when FMI or FMP beyond P90, the specificity of each abnormal lipid profiles was around 90%. Conclusions:The recommend cut-off points for body fat may be to assess children′s adiposity, and can be applied in preventive activities.

Objective: To describe the baseline characteristics of School-based Cardiovascular and Bone Health Promotion Program(SCVBH) in Beijing. Methods: Children and adolescents were selected in 30 schools (8 primary schools, 21 middle schools and one 12-year education school) from Dongcheng, Tongzhou, Fangshan and Miyun districts of Beijing by using a stratified cluster sampling method. 15 391 students in grade 1 to 4 from primary schools, grade 1 from junior and senior high schools were enrolled in the investigation with an exclusion of students who were not able to participate due to trauma or other uncomfortable physical conditions. The baseline survey including a questionnaire survey, physical examination and blood biochemical test was conducted from September 2017 to January 2018. Obesity, blood pressure, fasting blood glucose, lipid, bone density and grip were evaluated. Results: The prevalence of obesity, hypertension, hyperglycemia (impaired fasting glucose and diabetes), dyslipidemia, lower bone density were 22.3%(3 394), 14.8%(2 248), 10.4%(1 490), 20.3%(2 919) and 2.1%(316) in total respectively, and 27.2%(2 081), 16.3%(1 244), 12.8%(922), 22.2%(1 595) and 1.2%(94) for boys, 17.3%(1 313), 13.3% (1 004), 7.9%(568), 18.4%(1 324) and 2.9%(229) for girls. Boys had higher prevalence of obesity, hypertension, hyperglycemia, and dyslipidemia and lower prevalence of low bone density than girls (all P values <0.05) The mean of body mass index, systolic blood pressure, fasting plasma glucose and grip of boys were significantly higher than that of girls (all P values <0.05).The mean of body mass index, systolic blood pressure, fasting plasma glucose and grip of boys were significantly higher than that of girls (all P values <0.05), the mean of fat mass percentage, total cholesterol, triglyceride, high density lipoprotein-cholesterol and low density lipoprotein-cholesterol of boys were significantly lower than those of girls (all P values <0.05). Conclusion The prevalence of risk factors of chronic cardiovascular disease was high and the low bone density was appearing in children and adolescents in this study. The promotion of cardiovascular and bone health should be implemented in children and adolescents.