Internet addiction (IA) among adolescents is a serious public health problem around the world. However, there have been few studies that examine the association between IA and stressful life events and psychological symptoms among Chinese adolescent internet users. We examined the association between IA and stressful life events and psychological symptoms among a random sample of school students who were internet users (N=755) in Wuhan, China. Internet addiction, stressful life events, coping style and psychological symptoms were measured by self-rated scales. The prevalence rate of internet addiction was 6.0% among adolescent internet users. Logistic regression analyses indicated that stressors from interpersonal problem and school related problem and anxiety symptoms were significantly associated with IA after controlling for demographic characteristics. Analyses examining the coping style with the IA revealed that negative coping style may mediate the effects of stressful life events to increase the risk of IA. However, no significant interaction of stressful life events and psychological symptoms was found. These findings of the current study indicate a high prevalence of internet addiction among Chinese adolescent internet users and highlight the importance of stressors from interpersonal problem and school related problem as a risk factor for IA which mainly mediated through negative coping style.

Objectives: To explore the epidemiology characteristics of birth defects (BDs) in perinatal infants in Longgang District, Shenzhen City. Methods: Data used in this study was obtained from birth defects surveillance network during 2003 to 2009. The prevalence with 95% confidence interval of BDs by year, gender, household registration and type were examined. Cochran-Armitage trend tests were conducted to evaluate the tendency by year. Results: The overall prevalence of BDs in Longgang District was 13.43 (12.92, 13.95) per 1000 live births and there was an increasing trend from 2003 to 2009 in migrant and permanent population. Furthermore, the migrant population and male infant had a higher prevalence, OR = 1.22(1.09, 1.37), 1.21(1.11, 1.31) respectively. Congenital heart disease was the most common birth defect. Conclusions: Shenzhen city is confronted with severe challenges to prevent BDs. The preventive program of BDs, especially for the migrant population, should be better performed.

Objective: To determine if maternal percentage body fat (PBF) or fat free mass (FFM) in the early second trimester of pregnancy influenced the development of preeclampsia. Methods: A matched nested case-control study was conducted from a cohort study of 1668 women at Gansu provincial maternal and child care hospital from July 2007 to August 2011 in China. Maternal PBF and FFM were assessed by bioelectrical impedance analysis during 12th–16th gestational week. The demographic characteristics were all chart abstracted. After childbirth, 70 cases of preeclampsia were matched by race/age with 140 uncomplicated pregnancies women. Multivariate logistic regression analysis was performed to determine the associated risk factors. Results: Pre-pregnancy body mass index were higher in women who subsequently developed preeclampsia compared with controls (p < 0.001). During 12th–16th gestational week, there were nearly 7-fold increase in the odds of preeclampsia (adjusted OR: 6.84, 95% CI: 4.15–41.60) among women with PBF ≥ 40% versus women with PBF < 40%. But FFM were not at further increased risk of the development of preeclampsia (adjusted OR, 1.02; 95% CI, 0.6–3.6). Conclusion: Maternal PBF but not FFM is a predictor of preeclampsia in the early second trimester. Excessive adipose tissue possibly played an important role in developing of preeclampsia.

Introduction: Reduced bone mass will increase bone fragility and risk of fractures. Thus, it is better to note its determinants as early as possible. Objective: This study aimed to find and determine the determinants for low bone mineral density (BMD) in pre-school children. Methods: Between November 2014 and April 2015, a matched case-control study was performed to detect information on growth and development condition and consumption frequency of products of cases with low BMD and controls with normal BMD. Anthropometric data measurement and blood tests were conducted. Besides, the questionnaires concerning the mentioned information were completed to get relevant determinants. A paired t-test, the McNemar test and univariate and multiple conditional logistic regression models were used to explore the association between these factors and low BMD. Results: In total, 88 (28 boys, 60 girls) incident cases (4.15 ± 0.78 years) of low BMD and 88 sex- and age-matched (±2 months) controls (4.16 ± 0.80 years) of normal BMD were enrolled. The results of multiple conditional logistic regression analysis indicated that if children had larger chest circumference (odds ratio [OR] = 0.763), longer duration of breastfeeding (OR = 0.899) and lower frequency of eating snacks (OR = 0.439), the risk of low BMD would decrease. Conclusions: Our findings suggest that pre-school children with an association of larger chest circumference, longer duration of breastfeeding and lower frequency of eating snacks could have lower risk for low BMD. Intended measures to strengthen those protective factors could be effective in reducing the cases of low BMD.