The association of preconceptional folic acid supplementation with gestational age and preterm birth risk in twin pregnancies: a prospective cohort study in China.

PURPOSE: This study aims to explore the association of maternal preconceptional folic acid (FA) supplementation with gestational age and preterm birth in twin pregnancies, and whether the association varies by chorionicity or conception mode. METHODS: From November 2018 to December 2021, the information of FA supplementation and pregnancy outcomes were collected in twin pregnant women. The linear regression models and the logistic regression were used to test the association of preconceptional FA supplementation with gestational age at delivery and preterm birth and premature rupture of membranes (PROM). RESULTS: A total of 416 twin pregnancies were included. Compared with no use in twins, maternal preconceptional FA use was associated with a 0.385-week longer gestational age (95% CI 0.019-0.751) and lower risk of preterm birth < 36 weeks (adjusted OR 0.519; 95% CI 0.301-0.895) and PROM (adjusted OR 0.426; 95% CI 0.215-0.845). The protective effect on preterm birth < 36 weeks and PROM is similar whether taking FA supplements alone or multivitamins. However, the associations varied by chorionicity and conception mode of twins or compliance with supplementation. The positive associations between preconceptional FA use and gestational age only remained significant among twins via assisted reproductive technology or dichorionic diamniotic twins. Significant protective effects on preterm birth < 36 weeks and PROM were only found among women who took FA at least 4 times a week before conception. CONCLUSION: Maternal preconceptional FA supplementation was associated with longer gestation duration and lower risk of preterm birth < 36 weeks and PROM in twin pregnancies. To improve the success of their pregnancies, reproductive women should start taking FA supplements well before conception and with good compliance.

Assessing causal relationships between gut microbiota and asthma: evidence from two sample Mendelian randomization analysis.

Background: Accumulating evidence has suggested that gut microbiota dysbiosis is commonly observed in asthmatics. However, it remains unclear whether dysbiosis is a cause or consequence of asthma. We aimed to examine the genetic causal relationships of gut microbiota with asthma and its three phenotypes, including adult-onset asthma, childhood-onset asthma, and moderate-severe asthma. Methods: To elucidate the causality of gut microbiota with asthma, we applied two sample Mendelian randomization (MR) based on the largest publicly available genome-wide association study (GWAS) summary statistics. Inverse variance weighting meta-analysis (IVW) was used to obtain the main estimates; and Weighted median, MR-Egger, Robust Adjusted Profile Score (MR-RAPS), Maximum likelihood method (ML), and MR pleiotropy residual sum and outlier (MR-PRESSO) methods were applied in sensitivity analyses. Finally, a reverse MR analysis was performed to evaluate the possibility of reverse causation. Results: In the absence of heterogeneity and horizontal pleiotropy, the IVW method revealed that genetically predicted Barnesiella and RuminococcaceaeUCG014 were positively correlated with the risk of asthma, while the association between genetically predicted CandidatusSoleaferrea and asthma was negative. And for the three phenotypes of asthma, genetically predicted Akkermansia reduced the risk of adult-onset asthma, Collinsella and RuminococcaceaeUCG014 increased the risk of childhood-onset asthma, and FamilyXIIIAD3011group, Eisenbergiella, and Ruminiclostridium6 were correlated with the risk of moderate-severe asthma (all P<0.05). The reverse MR analysis didn't find evidence supporting the reverse causality from asthma and its three phenotypes to the gut microbiota genus. Conclusion: This study suggested that microbial genera were causally associated with asthma as well as its three phenotypes. The findings deepened our understanding of the role of gut microbiota in the pathology of asthma, which emphasizes the potential of opening up a new vista for the prevention and diagnosis of asthma.

The associations of chronotype and social jetlag with prosocial behavior problems among Chinese adolescents.

Potential relevance between the circadian rhythm and behavioral health has got raising attention in recent years. This study aimed to examine chronotype, social jetlag and their associations with prosocial behavior problems among Chinese adolescents. A total of 4,666 middle school students aged 12-18 years were enrolled in study. Sleep characteristics were collected by the modified Chinese version of Adolescent Sleep Hygiene Scale (M-ASHS); MSFsc and mid-sleep point were calculated to determine chronotypes and social jetlag. Prosocial behavior problems were assessed by the Strength and Difficult Questionnaire (SDQ). Multivariate logistic regression was applied to analyze the relationships between chronotype and social jetlag with prosocial behavior problems. Evening chronotype was associated with higher risk of prosocial behavior problems, whether among male (OR = 1.82, 95%CI:1.27-2.61, P = .001) or female adolescents (OR = 1.83, 95%CI:1.15-2.91, P = .011). Female adolescents with social jetlag of 1-2 hours had 1.60 times the risk of prosocial behavior problems than their peers whose social jetlag was <1 h (P = .028); social jetlag ≥ 2 h was positively associated with prosocial behavior problems in both male and female adolescents (OR = 1.79 and 2.45, respectively, both P < .05). Further, the combination of intermediate chronotype and social jetlag ≥ 2 h was correlated with prosocial behavior problems only in female adolescents (OR = 3.24, 95%CI = 1.40-9.21, P = .004). Evening chronotype and higher social jetlag were risk factors for prosocial behavior problems in adolescents, especially for the female. For the promotion of prosocial behavior in adolescents, the importance of circadian rhythm should be addressed.

Relationships between Sleep Duration, Timing, Consistency, and Chronotype with Myopia among School-Aged Children.

Background: The role of sleep in childhood myopia has been a research focus; however, the existing evidence is conflicting on sleep duration and timing, and as yet, no studies involve sleep consistency and chronotype. This study is done to make multiple-perspective analyses on the associations between sleep variables and myopia. Methods: A population-based cross-sectional study was conducted in Shanghai, China, which included 10,142 school-aged children (7-12 years old, 53.2% boys). The Chinese version of the Children's Sleep Habits Questionnaire (CSHQ) was used to assess sleep variables. Propensity score matching was adopted to balance the difference of covariates between nonmyopic and myopic groups. Logistic regression models were implemented to examine the associations between sleep variables and myopia. Results: Sleep duration and timing, mainly during weekdays, were correlated with myopia in a dose-dependent pattern, in which longer sleep duration was associated with decreased risk of myopia (9-10 hours/day: odds ratio (OR) = 0.87; ≥10 hours/day: OR = 0.77; by comparison with <9 hours/day); later bedtime (9 pm to 9:30 pm: OR = 1.46; 9:30 pm to 10 pm: OR = 1.51; 10 pm and after: OR = 2.08; by comparison with before 9 pm) and later wake-up time (7 am and after: OR = 1.36; by comparison with before 6:30 am) increased the risk (all P < 0.05). Moreover, longer weekend catch-up sleep duration and intermediate and evening chronotype were positively correlated with myopia, while social jetlag was associated with a lower odds of myopia. All these findings were also similarly observed in the matching sample. Conclusions: Multiple dimensions of sleep were involved in childhood myopia. In addition to sleep duration and timing, sleep consistency and chronotype were also strictly related to myopia. More studies are needed to enrich the current evidence, thus further clarifying the association between sleep and childhood myopia.

Exploring genetic association of insomnia with allergic disease and asthma: a bidirectional Mendelian randomization study.

BACKGROUND: Insomnia is highly prevalent among patients with allergic disease and asthma; however, few studies have investigated their causal relationship. We aim to explore the causal association between insomnia and allergic disease/asthma by performing bidirectional Mendelian randomization (MR) study. METHODS: Instrumental variables were constructed using single nucleotide polymorphisms (SNPs). Summary statistics for insomnia, allergic disease, and asthma were obtained from four large-scale genome-wide association studies (GWAS) of European ancestry. The pleiotropy analysis was applied by using the MR-Egger intercept test and the MR pleiotropy residual sum and outlier (MR-PRESSO) test. MR analyses were conducted by using inverse variance weighted (IVW), weighted median, and MR-Egger method. RESULTS: Based on the multiplicative random effects IVW method, the MR analysis showed that genetically predicted insomnia was causally associated with an increased risk of allergic disease [odds ratio (OR) = 1.054, 95% confidence interval (CI) = 1.031-1.078, P = 3.817 × 10-06], asthma (OR = 1.043, 95% CI = 1.010-1.077, P = 9.811 × 10-03), moderate-severe asthma (OR = 1.168, 95% CI = 1.069-1.277, P = 6.234 × 10-04), and adult-onset asthma (OR = 1.086, 95% CI = 1.037-1.138, P = 4.922 × 10-04). In bidirectional analyses, we did not find evidence supporting the reverse causality relations. CONCLUSIONS: Our MR study suggested that genetically predicted insomnia was the risk factor for allergic disease and asthma. Improving sleep quality could be one of the cornerstones in the prevention of allergic disease and asthma.

Sex-specific association of sleep duration with subclinical indicators of metabolic diseases among asymptomatic adults.

BACKGROUND: Accumulating evidence suggests sleep duration may be involved in metabolic regulation. However, studies regarding the association with the early stage of the metabolic disease are limited, and the findings were inconsistent. METHODS: A study among 4922 asymptomatic adults was conducted based on a Chinese national survey in 2009. The early stage of metabolic diseases was evaluated using three proxies: triglyceride to high-density lipoprotein cholesterol ratio (TG/HDL-C), the product of triglyceride and fasting glucose (TyG), and lipid accumulation product (LAP). Multivariable linear and logistic regression models were used to explore the associations of sleep duration with the three indicators. RESULTS: The linear regression models revealed that, among females, sleep duration <7 h per day, compared with 7-9 h, was associated with an increased value of LAP and TyG by 25.232% (95%CI: 10.738%, 41.623%) and 0.104 (95%CI: 0.024, 0.185), respectively, in the crude model. The effects were attenuated but remained significant for LAP (11.405%; 95%CI: 1.613%, 22.262%). Similarly, the logistic regression models further found that sleep duration <7 h per day could increase the risk of elevated LAP (OR: 1.725, 95CI%:1.042, 2.856) after adjusting for multiple covariates. By contrast, no associations were found among males. CONCLUSIONS: Short sleep duration was associated with subclinical indicators of metabolic diseases, and females were more susceptible to the association.

Trends of central obesity and associations with nutrients intake and daily behaviors among women of childbearing age in China.

BACKGROUND: Obesity among women of childbearing age has becoming an important public health concern. We aimed to describe the trends of central obesity among Chinese women of childbearing age from 2004 to 2011 and to examine its associations with nutrients intake and daily behaviors. METHODS: Longitudinal data were derived from the China Health and Nutrition Survey. Participants consisted of 2481 women aged 15-44 years old. WC (Waist circumference) and WHtR (Waist to height ratio) were adopted as indicators of central obesity. Generalized linear mixed model was performed to analyze the associations of nutrients intake and daily behaviors with central obesity. RESULTS: From 2004 to 2011, the prevalence of central obesity among Chinese women of childbearing age increased from 21.6 to 30.7% (WC as indice) or from 22.8 to 32.6% (WHtR as indice) (both p < 0.001). Protein intake above the AMDR (Acceptable macronutrient distribution range) (OR = 1.21, 95% CI 1.05-1.39, p < 0.01) and non-participation in LTPA (Leisure time physical activity) (OR = 1.45, 95% CI 1.17-1.80, p < 0.001) were risk factors for high WC, and the latter was also associated with high WHtR (OR = 1.36, 95% CI 1.10-1.67, p < 0.01). For those women who had high WC & high WHtR, the impacts of protein intake and LTPA became stronger, especial LTPA (OR = 1.53, 95% CI 1.21-1.94, p < 0.001). Age-stratified analyses found that non-participation in LTPA was key factor for central obesity in 15-34 age group, while protein intake above the AMDR was pronounced in the 35-44 age group. CONCLUSIONS: Non-participation in LTPA and protein intake above the AMDR were significant contributors of central obesity, which could be intervention targets to deal with the growing trend of central obesity among women of childbearing age.

The Associations of Trajectory of Sleep Duration and Inflammation with Hypertension: A Longitudinal Study in China.

BACKGROUND: Existing evidence suggested that sleep duration may be involved in hypertension; however, the conclusions were still controversial. This study aimed to examine the association of longitudinal trajectory of sleep duration with hypertension and to explore the role of the inflammation in such associations. METHODS: A total of 3178 subjects over 30 years of age without hypertension were enrolled in 2004, and they were followed until 2009. Self-reported sleep duration was recorded, and inflammation was measured by highly sensitive C reactive protein (hs-CRP). Log-binomial regression models were applied to examine the association of sleep duration trajectory and inflammation with the risk of hypertension. The mediating effect of elevated hs-CRP was examined by the bootstrap and the process software. RESULTS: The prevalence of persistent short (≤7 hours/day), normal (8-9 hours/day), and long (>9 hours/day) sleep duration over 5 years were 9.1%, 37.7%, and 2.3%, respectively. The incidence of hypertension was 26.6% during the follow-up period. Compared with those who persistently slept 8-9 hours/day from baseline to follow-up, those who persistently slept ≤7 hours/day, persistently slept ≥10 hours/day, and those whose sleep duration changed have higher risks of hypertension by 1.375-fold (95% CI: 1.121, 1.686), 1.557-fold (95% CI: 1.171, 2.069) and 1.299-fold (95% CI: 1.135, 1.487), respectively. In addition, persistently slept ≤7 hours/day was found to be associated with higher risk of inflammation (RR: 1.285, 95% CI: 1.008, 1.638). The mediation analysis did not find significant mediating effect of elevated CRP on the association between sleep duration trajectory and hypertension. CONCLUSION: Experiencing both a short or long sleep duration, especially for a long time, could lead to higher risk of hypertension. Persistent exposure to short sleep duration was also associated with inflammation. However, the higher risk of hypertension caused by persistent short sleep duration does not seem to be directly mediated through inflammation.

Prevalence of allergic diseases and associated factors among schoolaged children in Shanghai / 中国学校卫生

Objective@#To examine the prevalence of allergic diseases in schoolaged children from Shanghai and to explore related factors so as to produce epidemiological data regarding allergic diseases in children.@*Methods@#Multistage cluster sampling was used to carry out the study in Shanghai from April to June 2019. A total of 10 686 children aged 7-12 years from 17 primary schools participated in the survey. The International Study of Asthma and Allergies in Childhood (ISAAC)Scale was used to evaluate allergic diseases. Multivariate Logistic regression analysis was performed to analyze the related factors.@*Results@#The overall prevalence of allergic diseases among schoolaged children in Shanghai was 47.0%. A higher prevalence was observed among boys (50.4% vs 43.3% in girls, χ2=54.44, P<0.01). Common allergic diseases included asthma (13.9%), allergic rhinitis (18.2%), and atopic dermatitis (34.3%). The Logistic regression analysis showed that the common risk factors of asthma, allergic rhinitis and atopic dermatitis included the following:male gender (OR=1.52,1.44,1.22); mother has a bachelors degree or above (OR=1.26,1.77,1.84); family history of allergic diseases (OR=2.87,4.24,2.57); only child (OR=1.16,1.28,1.22); curtain cleaning frequency <1 time/month (OR=1.41,1.79,1.77); room not cleaned daily (OR=1.14,1.18,1.20); and dust exposure frequency ≥1 time/month (OR=1.45,1.56,1.42), all P<0.05. These three types of allergic diseases were also associated with unique risk factors that dependent on socialenvironmentalbehavioral factors.@*Conclusion@#Compared with previous data, the prevalence of allergic diseases among schoolaged children in Shanghai increased significantly in 2019. The related influencing factors involve multiple variables including demographics, environmental exposure and behavior, which warrant further exploration.

How to Understand "Herd Immunity" in COVID-19 Pandemic.

The COVID-19 pandemic has been a global threat. Through rapid and effective surveillance and control, the newly confirmed patients have been fluctuated at a very low level and imported case explained most of them through March, 2020 to the present, indicating China's response has achieved a stage victory. By contrast, the epidemic of COVID-19 in other countries out of China is bursting. Different countries are adopting varied response strategy in terms of their public health system to prevent the spread. Herd immunity has been a hot topic since the outbreak of COVID-19 pandemic. Can it be a possible strategy to combat COVID-19? To fully interpret the knowledge regarding the term upon the background of COVID-19-related health crisis, we aim to systematically review the definition, describe the effective measures of acquiring herd immunity, and discuss its feasibility in COVID-19 prevention. Findings from this review would promote and strengthen the international cooperation and joint efforts when confronting with COVID-19.

Gender-Specific Longitudinal Association of Sleep Duration with Blood Pressure among Children: Evidence from CHNS 2004-2015.

PURPOSE: We conducted this study to add the evidence regarding the gender-specific association between sleep duration and blood pressure (BP) in children. METHODS: A secondary analysis was performed among 1000 children aged 7-13 years, who had at least two rounds of survey records in China Health and Nutrition Survey through 2004-2015. Generalized estimating equation was used to explore the gender-specific association of sleep duration with BP. The subgroup analysis was applied in those participants with normal weight. RESULTS: The time trend of decreasing sleep duration, along with increasing BP level, was observed in each age group during the survey period. Short sleepers (<9 hours per day) have higher level of both systolic BP (SBP) and diastolic BP (DBP) than long sleepers in girls (all p < 0.05). By contrast, only SBP was higher in short sleepers among boys (p < 0.05). There was gender difference in the association between sleep duration and DBP (p for interaction <0.05). The stratification analysis showed that short sleep duration could consistently predict a higher level of diastolic BP (DBP) in both crude (ß = 2.968, 95% CI: 1.629, 4.306) and adjusted models (ß = 1.844, 95% CI: 0.273, 3.416) only in girls. Sleep duration was also analyzed as continuous variable, and the very similar associations were observed. Moreover, the established associations can be verified among children with normal weight. CONCLUSIONS: There was a time trend of decreasing sleep duration alongside increasing BP among children from 2004 to 2015. Short sleep duration was independently associated with increased DBP; however, only girls were susceptible to the association.