[Relationship between sleep status and occasional hypertension in preschool children in three provinces in the middle and lower reaches of the Yangtze River in China]

Objective: To understand the prevalence of occasional hypertension in preschool children in three provinces in the middle and lower reaches of the Yangtze River in China, and analyze the relationship between their sleep status and occasional hypertension. Methods: From October to November 2017, a total of 24 842 preschool children from 109 kindergartens in 11 cities in Hubei, Anhui and Jiangsu provinces were selected by intentional sampling method. A self-made questionnaire was used to collect basic information about the subjects, and the sleep status data was collected by the Children's Sleep Habits Questionnaire. Physical examinations were performed on the subjects, and height, weight and blood pressure were measured on-site. The difference in occasional hypertension detection rate among preschool children with different characteristics was compared, and the correlation between sleep status and occasional hypertension detection rate was analyzed by the multivariate logistic regression model. Results: The age of the subjects was (4.4±1.0) years, including 12 729 boys (51.2%). The prevalence of occasional hypertension was 31.8% (7 907/24 842). The prevalence of occasional hypertension among preschool children in three provinces of the middle and lower reaches of the Yangtze River was 31.8%. There were statistically significant differences in the detection rate of occasional hypertension among preschool children of different genders, age groups, family residence, family economic status and parents' education level (all P values<0.05). The detection rate of occasional hypertension in children with less than 10 hours of sleep was higher than those with sufficient sleep, and the difference was statistically significant (P<0.05). The results of multivariate logistic regression analysis showed that after adjusting for factors such as gender, age, family residence, family economic status, parental education level, parental smoking history, and physical constitution, the ORs (95%CI) for less than 10 hours of sleep, turning on the lights while sleeping, and poor sleep quality were 1.09 (1.03-1.15), 1.17 (1.07-1.28) and 1.04 (0.91-1.18), respectively, compared with the corresponding reference group. Conclusion: The detection rate of occasional hypertension is high in preschool children in the middle and lower reaches of the Yangtze River and there is a positive correlation between insufficient sleep and turning on the light when sleeping and occasional hypertension in preschool children.

[Emotional and behavioral problems associated with health-risk behaviors in preschool children]

Objective: To explore the relationship between multiple health-risk behaviors and emotional and behavioral problems in preschool children. Method: From October to November 2017, 27 987 children aged 3 to 6 years from 109 kindergartens of 11 cities from Hubei, Anhui and Jiangsu Provinces in the middle and lower reaches of the Yangtze River were selected by using the cluster sampling method. Finally, 27 200 valid questionnaires were collected. A questionnaire was used to investigate the demographic characteristics, video time and outdoor activities, eating behavior, sleep time, emotional and behavioral problems of parents and children. Multivariate logistic regression model was used to quantify the association between multiple health-risk behaviors and emotional and behavioral problems. Results: Emotional symptoms, conduct problems, hyperactivity, peer problems, total difficulties and prosocial behavior abnormalities were detected in 9.5% (2 587), 9.5% (2 590), 18.2% (4 958), 24.5% (6 670), 11.2% (3 058) and 10.2% (2 770), respectively. Three groups of low, medium and high scores of multiple health-risk behaviors were accounted for 30.6% (8 316), 60.9% (16 568) and 8.5% (2 316), respectively. Multivariate logistic regression model analysis showed that after controlling for the confounding factors, compared with those in the low score group, preschool children in the middle and high score groups had higher risks of emotional symptoms, conduct problems, hyperactivity, peer problems, total difficulties and prosocial behavior (all P values<0.05). Conclusion: Health-risk behaviors are associated with the emotional and behavioral problems of preschool children.

[Effects of parental rearing patterns and their consistency on the emotional and behavioral problems of preschool children]

Objective: To explore the effect of parental rearing patterns and their consistency on the emotional and behavioral problems of preschool children. Methods: From October to November 2017, 27 987 children aged 3 to 6 years old from 109 kindergartens in 11 cities of Hubei, Anhui and Jiangsu Provinces were selected by using the cluster sampling method. A total of 27 200 valid questionnaires which were completed by subjects' parents were collected. The emotional and behavioral problems of preschool children were collected by "strengths and difficulties questionnaire" and the parental rearing patterns were evaluated by the "Parental Behavior Scale". The differences in emotional and behavioral abnormality rates of preschool children with different characteristics were analyzed; with emotional and behavioral problems as dependent variables and parental support/participation and compulsion/hostility as independent variables, the multivariate logistic regression model was used to analyze the effect of parental rearing patterns and their consistency on the emotional and behavioral problems of preschool children. Results: The age of children was (4.35±0.96) years old, and 51.4% of children were 13 975 males. There were 24 634 (90.6%) urban children and 17 916 (65.9%) only children. Both parents with strong support/participation accounted for 14.9%, and those with poor support/participation accounted for 11.9%; both parents with strong compulsion/hostility accounted for 15.2%, and those with low compulsion/hostility accounted for 11.3%. The rates of emotional symptoms, conduct behavior, hyperactive behavior, peer interaction, total difficulty score, and abnormal prosocial behavior of preschool children were 9.5%, 9.5%, 18.2%, 24.5%, 11.2%, and 10.2%, respectively. The multivariate logistic regression model analysis showed that after adjusting for gender, only child, living area, family economic status, mother's age and education level, father's education level, and other factors, compared with fathers/mothers with strong support/participation and low compulsion/hostility and parents with strong support/participation and low compulsion/hostility, preschool children who had fathers/mothers with poor support/participation and strong compulsion/hostility or parents with poor support/participation and strong compulsion/hostility were more likely to have emotional symptoms, conduct behavior, hyperactive behavior, peer interaction, total difficulty score, and abnormal prosocial behavior (P<0.05). Conclusions: Parental rearing patterns and their consistency are related to the emotional and behavioral problems of preschool children.

[The associations between nighttime sleep duration, bedtime and preschool children's obesity]

Objective: To examine the relationship of nighttime sleep duration and bedtime with preschool children's obesity, and to explore possible early life risk factors for childhood obesity. Methods: A total of 14 946 valid children from 16 439 pre-school children aged 3-6 years in 91 kindergartens in Ma'anshan city participated in the study. The body mass index cut-offs for overweight and obesity in Chinese children and adolescents aged 2-18 years was used as the criterion for judging overweight and obesity, and pathological and secondary causes of obesity were excluded. The associations of nighttime sleep duration and bedtime with preschool children's obesity was analyzed by using non-conditional multivariate binary logistic regression model. Results: Among the preschool children, 22.4% (n=3 345) had shorter sleep duration. 9.5% (n=1 415) had bedtimes after 22:00 on weekdays and 21.8% (n=3 260) had bedtimes after 22:00 on weekends. The prevalence of overweight and obesity were 16.5% (n=2 466) and 10.5% (n=1 562), respectively. After the adjustent of age, gender, whether or not only child, residence in the last six months, parents' body mass index parents' educational level, diet preference, outdoor activities, TV viewing duration, sleep duration, bedtime on weekdays and weekends, only the shorter sleep duration (OR=1.25, 95%CI: 1.03-1.51) was still positively associated with the prevalence of obesity in preschool children. Conclusion: Shorter sleep duration was positively associated with the prevalence of obesity among preschool children.

Chloroplast analysis of Zelkova schneideriana (Ulmaceae): genetic diversity, population structure, and conservation implications

Zelkova schneideriana is endemic to China and belongs to the Ulmaceae. It is listed as a Near Threatened species in the China Biodiversity Red Data Book. We conducted a phylogeographical study of two chloroplast regions (psbA-trnH and trnG-trnM) in several Chinese Z. schneideriana populations, in order to examine the genetic diversity, population structure, and evolutionary history of the species. In all, 10 haplotypes were detected. The population from Sangzhi, Hunan, had the highest nucleotide diversity (π = 0.00653) and haplotype diversity (HD = 1.000), and should be considered the most suitable population to be protected under an in situ conservation strategy. Seed collections from as many individuals as possible in other populations would preserve the genetic diversity of Z. schneideriana.

Isolation and characterization of polymorphic microsatellite loci from Zelkova schneideriana Hand.-Mazz

Zelkova schneideriana is a highly valued hardwood species. An improved technique for isolating codominant compound microsatellite markers was used to develop simple sequence repeat markers for Z. schneideriana. A total of 12 microsatellite loci were identified. Overall, the number of alleles per locus ranged from 8-19, with an average of 11.75. Observed heterozygosity and expected heterozygosity values ranged from 0.109-0.709 and 0.832-0.929, respectively. Polymorphic information content is from 0.803-0.915, with an average of 0.854. These markers will be very important for future research related to the genetic diversity, population structure, patterns of gene flow, and mating system of this species.