Objectives: To investigate the associations between sexual-related knowledge, access to school and family sexuality education, and the experience of sexual intercourse, in order to make recommendations on sexuality education for vocational secondary school students in China. Methods: A cross-sectional study was conducted among 3180 vocational secondary school students in the Shanghai municipality and the Shaanxi province, China. Data were collected through an online, electronic questionnaire, which included socio-demographics, sexual-related knowledge, sources of information, and sexual-related behaviors. Results: The score on sexual-related knowledge among girls (53.8) is higher than that of boys (48.8), and that of participants from Shanghai (55.2) is higher than their counterparts from Shaanxi (47.6). The proportions of girls (70% and 41.7%, respectively) and participants from Shanghai (65% and 35.7%, respectively) who reported acquiring sexual information from their schools/teachers and parents are higher than that of boys (54.3% and 21.0%, respectively) and their counterparts from Shaanxi (59.7% and 27.4%, respectively). About 6% of participants had experienced sexual intercourse and 10% had watched porn actively. Experience of sexual intercourse was associated with higher sexual-related knowledge scores (OR = 1.01, 95% CI: 1.00–1.02) and active porn watching (OR = 2.63, 95% CI: 1.79–3.84) but was not associated with school and family sexuality education. Conclusions: Vocational secondary school students had poor sexual knowledge and inadequate school and family sexuality education. School and family-based comprehensive sexuality education should be promoted among vocational secondary school students.
Background: Social media (SM) has received considerable attention as a potential risk factor for adolescent suicide. Few empirical studies, however, have examined adolescents’ daily negative and positive experiences on SM and its proximal impacts on suicidal ideation (SI), particularly using intensive monitoring designs. Method: Adolescents (N= 60; 14-17 years; 49% girls; 62% LGBTQ+) recruited using SM across the United States and participated in an 8-week intensive monitoring protocol. Ecological momentary assessment (3 brief surveys per day) asked about negative and positive SM experiences and SI (passive and active). Multilevel modeling was used to evaluate the within-person relationships between daily SM experiences (e.g., individual fluctuations compared to a person’s average) and SI, controlling for average levels of SM experiences, SM use screen time, and lifetime SI. Results: Significant within-person effects of negative and positive SM experiences were associated with days when adolescents had SI. Specifically, on days when teens endorsed more frequent negative SM experiences than usual, they were more likely to report SI. However, more positive SM experiences than usual were associated with a lower likelihood of having SI. There were no significant effects of SM use (“screen time”) on SI or on the reverse associations of SI on next-day SM experiences. Conclusions: Results indicate that SM experiences may be dynamic and modifiable risk and protective factors for SI in adolescents, whereas there is no effect of SM screen time on SI. Our results highlight that targeting negative SM experiences and augmenting the positive experiences on SM may be critical targets to improve teens’ mental health and prevent suicide, rather than focusing on limiting SM screen time.
Objective: To analyze the relationship between the new simplified insulin resistance index and bone mineral content (BMC) in adolescents and its evaluation effect on low bone mass, so as to provide scientific basis for early identification and prevention of skeletal-related diseases in adolescents. Design and method: A total of 1594 adolescents aged 12-18 years in Yinchuan were selected by stratified cluster sampling. Binary Logistic regression was used to analyze the relationship between insulin resistance index and low bone mass, and receiver operating characteristic (ROC) curve was constructed to analyze its evaluation effect on low bone mass. Results: After adjusting for confounding factors, the new simplified insulin resistance index was positively correlated with BMC level (TyG: r = 0.113, TyG-BMI: r = 0.576, TG / HDL-C: r = 0.205) (all P < 0.001). After further adjustment of obesity index, the relationship between IR index and BMC turned into negative correlation. Logistic regression results showed that IR was a protective factor for low bone mass (TyG: OR = 0.74, 95% CI: 0.54∼1.03, TyG-BMI: OR = 0.95, 95% CI: 0.94∼0.95, TG / HDL-C: OR = 0.40, 95% CI: 0.26∼0.62) (all P < 0.05). After adjusting the obesity index, the above results were completely reversed. IR was a risk factor for low bone mass in girls (TyG: OR = 4.95, 95% CI = 1.29∼18.95; TG / HDL-C: OR = 4.38,95% CI = 1.04∼18.50) (all P < 0.05). ROC curve showed that TyG-BMI had the best evaluation effect on low bone mass(AUC=0.80,95%CI: 0.769∼0.825)(P<0.001). Conclusions: TyG-BMI can be used to identify low bone mass, which is of great significance for early prevention of bone-related diseases in adolescents. The relationship between IR and BMC is affected by obesity indicators. It is necessary to understand the complex relationship between IR, fat and bone mass more clearly.
目的 研究青少年不同强度身体活动水平和身体成分指标之间的相关性,为中国青少年身体成分的改善提供指导.方法 采用随机数编码抽样法,于2019年9-12月在北京市清华附中等8所中学抽取971名初、高中学生进行基于生物电阻抗的身体成分测量和基于加速度计的身体活动水平测量.采用独立样本t检验、Pearson相关系数法和多元线性回归法进行统计学分析.结果 初、高中阶段男生静坐行为(SB)均低于女生,高强度身体活动(VPA)和中高强度身体活动(MVPA)均高于女生(t值分别为-1.98,-8.09;5.20,4.52;3.53,4.03,P值均＜0.05);男生低强度身体活动(LPA)、中等强度身体活动(MPA)仅高中阶段高于女生(t值分别为3.67,5.63,P值均＜0.01).初中男生全身LM与MVPA(β=0.302),全身骨矿物质含量(BMC)与 SB(β=-0.001)、MVPA(β=0.002),全身脂肪含量(FM)与 SB(β=0.050)、MVPA(β=-0.323)之间存在相关关系;初中女生全身LM与LPA(β=0.080)、MVPA(β=0.613),全身BMC与SB(β=-0.004)、MVPA(β==0.008),全身FM与MVPA(β=-0.237)之间存在相关关系;高中男生全身LM与MVPA(β=0.393),全身BMC与SB(β=-0.001)、MVPA(β=0.002),全身FM与MVPA(β=-0.393)之间存在相关关系;高中女生全身LM与LPA(β=0.063)、MVPA(β=0.601),全身FM与SB(β=0.029)、MVPA(β=-0.529)之间存在相关关系(P值均＜0.05).结论 青少年身体活动水平和身体成分特征存在性别差异和定量化的相关关系.相关部门应为青少年提供个性化的身体活动剂量指导,改善青少年的身体素质.
Objective To investigate the influencing factors of preschoolers’ hyperopia reserve, and to provide a scientific basis for preschoolers to prevent myopia. Methods Visual screening and a questionnaire survey were conducted on 5 087 4-year-old children in Suzhou High-tech Zone from September to December in 2020. The influencing factors of children’s hyperopia reserve were analyzed by univariate analysis and Logistic regression model. Results A total of 997（19.6%） children had hyperopia reserve deficiency. Logistic regression showed that the negative factors associated with hyperopia reserve included being girl（OR=0.81, 95%CI=0.70-0.93）, no food allergy（OR=0.78, 95%CI=0.63-0.96）; and the positive factors included father myopia（OR=1.20, 95%CI=1.03-1.39）, mother myopia（OR=1.17, 95%CI=1.01-1.36）, exposure of night lights（for less than 1 hour: OR=1.53, 95%CI=1.21-1.92; for 1 to 3 hours: OR=1.48, 95%CI=1.09-2.00）, insufficient vegetable intake（OR=1.26, 95%CI=1.07-1.46）（P＜0.05）. Conclusion Parental myopia, nighttime sleep environment and dietary factors have potential associations with hyperopia reserve deficiency among children. Corresponding measures should be actively taken to improve the preschoolers’ hyperopia reserve.
