Dehydration and Suboptimal Sleep Aggravate Early Renal Impairment in Children: Longitudinal Findings from the PROC Study.

BACKGROUND: While dehydration is associated with pediatric renal impairment, the regulation of hydration status can be affected by sleep. However, the interaction of hydration and sleep on kidney health remains unclear. METHODS: We conducted a cohort study among 1914 healthy primary school children from October 2018 to November 2019 in Beijing, China. Four-wave urinary ß2-microglobulin and microalbumin excretion were assayed to assess transient renal tubular and glomerular impairment, and specific gravity was measured to determine hydration status with contemporaneous assessment of sleep duration, other anthropometric, and lifestyle covariates. We used generalized linear mixed-effects models to assess longitudinal associations of sleep duration and hydration status with renal impairment. RESULTS: We observed 1378 children with optimal sleep (9-<11 h/d, 72.0%), 472 with short sleep (<9 h/d), and 64 with long sleep (≥11 h/d, 3.3%). Over half (55.4%) of events determined across 6968 person-visits were transient dehydration, 19.4% were tubular, and 4.9% were glomerular impairment events. Taking optimal sleep + euhydration as the reference, the results of generalized linear mixed-effects models showed that children with long sleep + dehydration (odds ratio [OR]: 3.87 for tubular impairment [tubules] and 3.47 for glomerular impairment [glomerulus]), long sleep + euhydration (OR: 2.43 for tubules), optimal sleep + dehydration (OR: 2.35 for tubules and 3.00 for glomerulus), short sleep + dehydration (OR: 2.07 for tubules and 2.69 for glomerulus), or short sleep + euhydration (OR: 1.29 for tubules) were more likely to present transient renal impairment, adjusting for sex, age, body mass index z-score, systolic blood pressure z-score, screen time, physical activity, and Mediterranean diet adherence. CONCLUSIONS: Dehydration and suboptimal sleep aggravate transient renal impairment in children, suggesting its role in maintaining pediatric kidney health.

Sex-Specific Differences in Left Ventricular Mass and Volumes with Body Mass Index among Children Aged 6 to 8: A Cross-Sectional Study in China.

Few studies have examined the sex differences in left ventricle (LV) structure and physiology from early life stages. We aimed to assess the role of sex and overweight/obesity on left ventricular mass (LVM) and LV volume in Chinese children without preexisting cardiovascular risk factors. We selected 934 healthy children aged 6-8 years from an existing cohort in Beijing, China. Linear regression models were used to regress body mass index (BMI), fat mass, systolic blood pressure, diastolic blood pressure, waist circumference, and visceral fat area (VFA) with LVM, left ventricle end-diastolic volume (LVEDV) and end-systolic volume (LVESV). Higher BMI, fat mass, waist circumference, VFA, and stroke volume (SV) predicted higher LVM, LVEDV, and LVESV in both sexes. Multivariable analysis showed that boys with an elevated BMI had greater LV hypertrophy. LVEDV and LVESV were higher among boys than among girls and increased with higher BMI in both boys and girls. LVEDV and LVESV were associated with VFA in boys. We observed sex differences in LVM, LVESV, and LVEDV among prepubertal children, independent of obesity, with higher values observed in boys. Sex differences in cardiac structure in children may help explain the higher incidence of cardiovascular disease in male adults. Whether interventions to reduce childhood obesity can improve the trajectory of cardiac dynamics is worth investigating.

Validation of "Life's Essential 8" Metrics With Cardiovascular Structural Status in Children: The PROC Study in China.

Background Life's Essential 8 (LE8) metrics for cardiovascular health (CVH) aid primordial prevention in US populations. Methods and Results We conducted a child cohort study (PROC [Beijing Child Growth and Health Cohort]) with baseline (2018-2019) and follow-up (2020-2021) assessments, enrolling disease-free 6- to 10-year-old children from 6 elementary schools in Beijing. We collected LE8-assessed components via questionnaire surveys and 3 cardiovascular structural parameters by 2-dimensional M-mode echocardiography: left ventricular mass (LVM), LVM index, and carotid intima-media thickness. Compared with 1914 participants (mean age, 6.6 years) at baseline, we saw lower mean CVH scores at follow-up (n=1789; 8.5 years). Among LE8 components, diet presented the lowest perfect-score prevalence (5.1%). Only 18.6% of participants had physical activity ≥420 min/wk, 55.9% had nicotine exposure, and 25.2% had abnormal sleep duration. Prevalence of overweight/obesity was 26.8% at baseline and 38.2% at follow-up. We noted optimal blood lipid scores in 30.7%, while 12.9% of children had abnormal fasting glucose. Normal BP was 71.6% at baseline and 60.3% at follow-up. LVM (g), LVM index (g/m2.7), and carotid intima-media thickness (mm) were significantly lower in children with high (56.8, 33.2, 0.35) or moderate CVH scores (60.6, 34.6, 0.36), compared with children with low CVH scores (67.9, 37.1, 0.37). Adjusting for age/sex, LVM (ß=11.8 [95% CI, 3.5-20.0]; P=0.005), LVM index (ß=4.4 [95% CI, 0.5-8.3]; P=0.027), and carotid intima-media thickness (ß=0.016 [95% CI, 0.002-0.030]; P=0.028) were higher in the low-CVH group. Conclusions CVH scores were suboptimal, declining with age. LE8 metrics indicated worse CVH in children with abnormal cardiovascular structural measurements, suggesting the validity of LE8 in assessing child CVH. Registration URL: https://www.chictr.org.cn/index.html; Unique identifier: ChiCTR2100044027.

Maternal emotional regulation strategy is associated with newborn feeding practices within 72 h after delivery: Cross sectional analyses of a multi-center study in China.

BACKGROUND: Early feeding practices have a great impact on the growth and development of infants, and the health of mothers. Maternal emotional regulation (ER) is closely related to infant feeding practices. Exploring the relationship between ER strategy and feeding practice can inform early exclusive breastfeeding (EBF) interventions. METHODS: Using baseline survey of a longitudinal study, 965 mothers in Chongqing municipality, Guangzhou city, and Huizhou city were enrolled. At baseline, the study used self-administrated questionnaires to investigate the socio-demographic characteristics, maternal ER strategies and feeding practice within 72 h of delivery. Chi-square test and logistic regression were used to determine the associations of the mothers' ER and feeding practices within 72 h postpartum. RESULTS: Among 965 participants, 27.8 % of mothers practiced EBF, and 69.5 % of mothers reported getting breastfeeding education from health providers. The average scores on the cognitive reappraisal and the expressive suppression of the ERQ were 29.95 ± 7.24 and 14.47 ± 5.16 respectively. Multivariable analysis showed women with expressive suppression were less likely to practice EBF (aOR = 0.96, 95%CI: 0.93-0.98, p = 0.002), while receiving breastfeeding education was positively associated with EBF (aOR = 1.52, 95%CI: 1.09-2.12, p = 0.013). LIMITATIONS: Because the study started during the COVID-19 pandemic, the lock-down measures paused recruitments for quite some time reducing the enrollment of participation. The data we used was within 72 h postpartum, hence the period of time to study feeding practices was short. CONCLUSION: Mothers' ER strategy and breastfeeding education need to be addressed as part of interventions designed to improve EBF rates during the newborn period in China.

Interplay of Lymphocytes with the Intestinal Microbiota in Children with Nonalcoholic Fatty Liver Disease.

Abnormally high lymphocyte counts are seen in persons with nonalcoholic fatty liver disease (NAFLD). Gut microbiota dysbiosis is a risk factor for NAFLD. We assessed the gut microbiota of 63 healthy children and 63 children with NAFLD using 16S rRNA gene and metagenomic sequencing to explore the relationships. Compared with healthy children (HC group), the Bacteroidetes, Verrucomicrobia, and Akkermansia were less abundant, while the Actinobacteria were more abundant in children with NAFLD (FLD group). To understand the effect of lymphocytes on the gut microbiota of children with NAFLD, we compared the microbiota of 41 children with NAFLD and high numbers of lymphocytes (FLD_HL group) and 22 children with NAFLD and low numbers of lymphocytes (FLD_LL group). The abundances of Bacteroidetes, Verrucobacterium, and Akkermansia increased and Actinobacteria decreased in the FLD_LL group compared to the FLD_HL group. Akkermansia was negatively correlated with lymphocyte count. NAFLD may disturb the gut microbiota in children through reducing the abundance of Akkermansia and increasing the abundance of proinflammatory bacteria, such as Escherichia-Shigella. Conclusions: High lymphocyte counts are associated with disturbances of gut microbiota and emergence of opportunistic pathogens in children with NAFLD.

Predictors of Influenza Vaccination among Chinese Middle School Students Based on the Health Belief Model: A Mixed-Methods Study.

Influenza vaccination rates among Chinese middle school students are low. This study aims to explore the influencing factors of vaccination among middle school students and promote vaccination. We conducted a mixed-methods study, integrating a questionnaire survey among 9145 middle school students in four cities in China and semi-structured interviews with 35 middle school students to understand their attitudes and perceptions toward vaccination based on the Health Belief Model. We found the overall vaccination rate was 38.2% (3493/9145), with students in Beijing, boarding at school, or senior high school showing higher values than their counterparts (p < 0.05). Multiple logistic regression results showed that non-boarding (OR = 0.46, 95%CI: 0.42−0.51) and perceived barriers (OR = 0.97, 95%CI: 0.96−0.98) were unfavorable factors for influenza vaccination, whereas perceived susceptibility (OR = 1.07, 95%CI: 1.05−1.08), perceived benefits (OR = 1.02, 95%CI: 1.01−1.04), cues to action (OR = 1.08, 95%CI: 1.05−1.11), and self-efficacy (OR = 1.04, 95%CI: 1.02−1.07) were facilitators. Qualitative results indicated that positive health beliefs, school, and the home environment contribute to vaccination. In conclusion, the influenza vaccination rate among middle school students remains low. The concerns about the safety and potential side effects of vaccines are the main barriers to vaccination, underscoring the need for strengthening communication, education, and information among students and their teachers/parents.

Passive Smoking Exposure Modifies Cardiovascular Structure and Function: Beijing Child Growth and Health Cohort (PROC) Study.

Passive smoking exposure in children is prevalent worldwide and exposes children to respiratory and systemic toxins. In this study, we enrolled 568 children to study how secondhand smoke (SHS) might affect children's cardiovascular health in China. The measurement of nicotine and its metabolites in urine showed that 78.9% of children were exposed to SHS. Children exposed to SHS had greater interventricular septum thickness (p = 0.005) and left ventricular mass index (p = 0.008) than nonexposed children. Urinary norcotinine levels were associated with increased ascending aorta diameter (ß = 0.10, 95%CI 0.02-0.17) and decreased left ventricular end systolic diameter (ß = -0.10, 95%CI -0.19 to -0.01). The effects of SHS exposure on cardiovascular function: norcotinine levels associated with lower left ventricular mass index (ß = -0.32, 95%CI -0.59 to -0.05), left ventricular end diastolic volume index (ß = -0.43, 95%CI -0.85 to -0.02), and left ventricular end systolic volume index (ß = -0.20, 95%CI -0.37 to -0.03). Moreover, there no no significant associations of nicotine, cotinine, and trans-3'-hydroxycotinine with cardiovascular health. Overall, SHS exposure in children remains prevalent in Beijing and may affect children's cardiovascular development, in both structure and function. It suggests that stricter and practical measures are needed toward the elimination of tobacco use in children's environments.

Hearing thresholds elevation and potential association with emotional problems among 1,914 children in Beijing, China.

Objectives: School-aged children may experience hearing loss and emotional problems. Previous studies have shown a bidirectional relationship between hearing loss and emotional problems in the elderly population, and we aimed to analyze the association between hearing thresholds and emotional problems in school-aged children. Methods: Based on the Beijing Child Growth and Health Cohort (PROC) study, the hearing screenings were conducted in November 2019 using pure tone audiometry. A total of 1,877 parents completed the Strengths and Difficulties Questionnaire (SDQ) to assess children's emotional and behavioral status. We used generalized linear regression analysis to assess the potential association of emotional problems with hearing thresholds, based on multiple imputed datasets with a sample size of 1,914. Results: The overall pass rate of hearing screening was 91.5%. The abnormal rate of SDQ total difficulties was 55.8%. Emotional symptoms were positively associated with left ear average hearing thresholds (ß = 0.24, 95%CI: 0.08-0.40), and right ear average hearing thresholds (ß = 0.18, 95%CI: 0.04-0.32). Conduct problems, hyperactivity/inattention, peer problems, and prosocial behaviors had no association with the pass rate of the hearing screening. Regarding emotional symptoms, boys with many fears and who are easily scared coincided with increased right ear average hearing thresholds (ß = 0.67, 95%CI: 0.01-1.33). Girls having many worries, frequently feeling unhappy and downhearted were positively associated with left and right ear average hearing thresholds, respectively (ß = 0.96, 95%CI: 0.20-1.73; ß = 0.72, 95%CI: 0.07-1.37). Conclusions: The co-occurrence of hearing problems and emotional problems of children aged 6-8 in Beijing attracts attention. It is important to address undiscovered hearing loss and emotional problems from the perspective of comorbidity driving factors.

Good Adherence to the Mediterranean Diet Lowered Risk of Renal Glomerular Impairment in Children: A Longitudinal Study.

Healthy diet patterns have a positive effect on chronic non-communicable diseases in the pediatric population, but the evidence is limited on the association between kidney impairment and adherence to a Mediterranean diet. We aim to determine the associations between Mediterranean diet adherence and longitudinal tubular and glomerular impairment in children. Based on four waves of urine assays conducted from October 2018 to November 2019, we assayed urinary ß2-microglobulin (ß2-MG) and microalbumin (MA) excretion to determine transient renal tubular and glomerular impairment during the follow-up of the child cohort (PROC) study in Beijing, China. We assessed Mediterranean diet adherence using the 16-item Mediterranean Diet Quality Index in children and adolescents (KIDMED) among 1914 primary school children. Poor, intermediate, and good adherence rates for the Mediterranean diet were 9.0% (KIDMED index 0-3), 54.4% (KIDMED index 4-7) and 36.5% (KIDMED index 8-12), respectively. A short sleep duration was more prevalent in children with lower Mediterranean diet adherence, with no significant differences presenting in the other demographic and lifestyle covariates. The results of linear mixed-effects models showed that a higher urinary MA excretion was inversely associated with a higher KIDMED score (ß = -0.216, 95%CI: -0.358, -0.074, p = 0.003), after adjusting for sex, age, BMI z-score, SBP z-score, screen time, sleep duration and physical activity. Furthermore, in generalized linear mixed-effects models, consistent results found that transient renal glomerular impairment was less likely to develop in children with intermediate Mediterranean diet adherence (aOR = 0.68, 95%CI: 0.47, 0.99, p = 0.044) and in children with good Mediterranean diet adherence (aOR = 0.60, 95%CI: 0.40, 0.90, p = 0.014), taking poor Mediterranean diet adherence as a reference. We visualized the longitudinal associations between each item of the KIDMED test and kidney impairment via a forest plot and identified the main protective eating behaviors. Children who adhere well to the Mediterranean diet have a lower risk of transient glomerular impairment, underscoring the necessity of the early childhood development of healthy eating patterns to protect kidney health.

Interaction of Hydration Status and Physical Activity Level on Early Renal Damage in Children: A Longitudinal Study.

Background: Optimal water intake positively affects various aspects of human physiology, especially renal function. Physical activity (PA) may have an impact on hydration status and renal health, but the interaction of hydration status and PA level on renal function is not well-studied in children. Methods: We conducted four waves of urine assays in our child cohort (PROC) study from October 2018 to November 2019 in Beijing, China. We measured urinary specific gravity, ß2-microglobulin (ß2-MG), and microalbumin (MA) excretion to assess hydration status and renal damage in the context of PA level and other covariates among 1,914 primary school children. We determined the associations of renal damage with the interaction of hydration status and PA level using generalized linear mixed-effects models. Results: The prevalence of dehydration was 35.0%, 62.1%, 63.9%, and 63.3%, and the prevalence of insufficient PA was 86.2%, 44.9%, 90.4%, and 90.2% from wave 1 to wave 4 among 1,914 primary school children. From wave 1 to wave 4, the prevalence of renal tubular damage had a significant increasing trend of 8.8%, 15.9%, 25.7%, and 29.0% (Z = 16.9, P < 0.001), while the prevalence of glomerular damage revealed a declining trend of 5.6%, 5.5%, 4.4%, and 4.1% (Z = -2.4, P = 0.016). There were stable longitudinal associations of renal tubular and glomerular damage with hydration status (euhydration: OR = 0.50 and 0.33, respectively) but not with PA level. In multivariate analysis, significant interactions of hydration status and PA level were noted with renal tubular damage (ß = 0.43, P = 0.014) and glomerular damage (ß = 0.60, P = 0.047). Children with euhydration and insufficient PA were less likely to have renal tubular damage (OR = 0.46, 95% CI: 0.39, 0.53) or glomerular damage (OR = 0.28, 95% CI: 0.20, 0.39); children with euhydration and sufficient PA were also less likely to have renal tubular damage (OR = 0.57, 95% CI: 0.44, 0.75) or glomerular damage (OR = 0.47, 95% CI: 0.30, 0.74), adjusting for age, sex, BMI z-score, standardized SBP, sleep duration, computer/cell phone screen time, and fruit and vegetable intake. Conclusion: Children with euhydration and either sufficient or insufficient PA were less likely to have early renal damage. Adequate daily water intake for children is important, especially after PA.

Timing of Breastfeeding Initiation Mediates the Association between Delivery Mode, Source of Breastfeeding Education, and Postpartum Depression Symptoms.

Background: Emergency cesarean section (EMCS) and breastfeeding difficulties increase the risk of postpartum depressive (PPD) symptoms. Early initiation of breastfeeding (EIBF) may not only alleviate PPD symptoms but also facilitate subsequent breastfeeding success. EMCS is a risk factor for not practicing EIBF. Therefore, it is important to understand the relationship between EMCS, EIBF, and PPD symptoms. Methods: We conducted a prospective cohort study in three areas of China. At baseline, a total of 965 mothers completed electronic questionnaires within 72 h postpartum. Women were screened for PPD symptoms using the Edinburgh Postpartum Depression Scale (EPDS). Multivariate logistic regression was used to identify the determinants of PPD symptoms. Mediation analysis was used to determine if EIBF mediated the relationship between delivery mode or breastfeeding education source and PPD symptoms. Results: The prevalence of EIBF was 40.6%; 14% of 965 mothers experienced EMCS, and 20.4% had PPD symptoms. The risk factors for developing PPD symptoms were excessive gestational weight gain (adjusted odds ratio [aOR] = 1.55, confidence interval [95% CI]: 1.03−2.33, p = 0.037) and EMCS (aOR = 2.05, 95% CI: 1.30−3.25, p = 0.002). The protective factors for developing PPD symptoms were monthly household income over CNY 10000 (aOR = 0.68, 95% CI: 0.47−0.97, p = 0.034), EIBF (aOR = 0.49, 95% CI: 0.34−0.72, p < 0.001), and prenatal breastfeeding education from nurses (aOR = 0.46, 95% CI: 0.29−0.73, p = 0.001). EIBF indirectly affected PPD symptoms in patients who had undergone EMCS (percentage mediated [PM] = 16.69, 95% CI: 7.85−25.25, p < 0.001). The source of breastfeeding education through EIBF also affected PPD symptoms (PM = 17.29, 95% CI: 3.80−30.78, p = 0.012). Conclusion: The association between EMCS on PPD symptoms was mediated by EIBF. By providing breastfeeding education, nurses could also help alleviate PPD symptoms.

Insufficient Fruit and Vegetable Intake and Low Potassium Intake Aggravate Early Renal Damage in Children: A Longitudinal Study.

Insufficient fruit and vegetable intake (FVI) and low potassium intake are associated with many non-communicable diseases, but the association with early renal damage in children is uncertain. We aimed to identify the associations of early renal damage with insufficient FVI and daily potassium intake in a general pediatric population. We conducted four waves of urine assays based on our child cohort (PROC) study from October 2018 to November 2019 in Beijing, China. We investigated FVI and other lifestyle status via questionnaire surveys and measured urinary potassium, ß2-microglobulin (ß2-MG), and microalbumin (MA) excretion to assess daily potassium intake and renal damage among 1914 primary school children. The prevalence of insufficient FVI (<4/d) was 48.6% (95% CI: 46.4%, 50.9%) and the estimated potassium intake at baseline was 1.63 ± 0.48 g/d. Short sleep duration, long screen time, lower estimated potassium intake, higher ß2-MG and MA excretion were significantly more frequent in the insufficient FVI group. We generated linear mixed effects models and observed the bivariate associations of urinary ß2-MG and MA excretion with insufficient FVI (ß = 0.012, 95% CI: 0.005, 0.020; ß = 0.717, 95% CI: 0.075, 1.359), and estimated potassium intake (ß = −0.042, 95% CI: −0.052, −0.033; ß = −1.778, 95% CI: −2.600, −0.956), respectively; after adjusting for age, sex, BMI, SBP, sleep duration, screen time and physical activity. In multivariate models, we observed that urinary ß2-MG excretion increased with insufficient FVI (ß = 0.011, 95% CI: 0.004, 0.018) and insufficient potassium intake (<1.5 g/d) (ß = 0.031, 95% CI: 0.023, 0.038); and urinary MA excretion increased with insufficient FVI (ß = 0.658, 95% CI: 0.017, 1.299) and insufficient potassium intake (ß = 1.185, 95% CI: 0.492, 1.878). We visualized different quartiles of potassium intake showing different renal damage with insufficient FVI for interpretation and validation of the findings. Insufficient FVI and low potassium intake aggravate early renal damage in children and underscores that healthy lifestyles, especially adequate FVI, should be advocated.

COVID-19 Vaccine Hesitancy among Adolescents: Cross-Sectional School Survey in Four Chinese Cities Prior to Vaccine Availability.

To address the novel coronavirus disease (COVID-19) pandemic, development and regulatory evaluations have been accelerated for vaccines, authorizing emergency use. To anticipate vaccine preparedness in adolescents, we studied COVID-19 vaccination awareness and willingness to vaccinate before the vaccine became available. We conducted a cross-sectional survey among 9153 (4575 boys, 50%) students with a mean age of 14.2 years old in four cities in China to collect information on demographic characteristics and their COVID-19 vaccination concerns. Multinomial logistic regression was used to analyze the influencing factors of vaccine hesitancy ("not sure") and resistance ("do not want it"). The results showed that 2891 (31.6%) were hesitant and 765 (8.4%) were resistant to being vaccinated. Additionally, multivariable analyses showed that vaccine hesitancy and vaccine resistance were associated with living in the Beijing area (OR = 1.62; 95% CI: 1.40-1.88; OR = 1.81; 95% CI: 1.44-2.28), lack of influenza vaccination experience (OR = 1.33; 95% CI: 1.14-1.55; OR = 1.57; 95% CI: 1.25-1.98), no perceived susceptibility (OR = 1.72; 95% CI: 1.50-1.97; OR = 3.57; 95% CI: 2.86-4.46), and perceiving no cues to action (OR = 3.24; 95% CI: 2.56-4.11; OR = 27.68; 95% CI: 21.81-35.13). Postulating a highly effective vaccine (OR = 0.84; 95% CI: 0.72-0.98; OR = 0.66; 95% CI: 0.52-0.83) decreased both vaccine hesitancy and resistance. Vaccine hesitancy alone was associated with girls (OR = 1.21; 95% CI: 1.09-1.36) and was less common among students boarding at school (OR = 0.79; 95% CI: 0.68-0.92), postulating convenient vaccine access (OR = 0.84; 95% CI: 0.73-0.96), and having doctors' recommendation (OR = 0.86; 95% CI: 0.76-0.98). In conclusion, the results of the study showed that vaccine hesitancy among students in China was associated with limited health literacy and lower risk awareness. Our findings in China suggest that educating youth regarding COVID-19 and the safety and effectiveness of immunization help reduce concerns and increase vaccine confidence and acceptance.

Dehydration Status Aggravates Early Renal Impairment in Children: A Longitudinal Study.

Dehydration is common in children for physiological and behavioral reasons. The objective of this study was to assess changes in hydration status and renal impairment across school weekdays. We conducted a longitudinal study of three repeated measures of urinalysis within one week in November 2019 in a child cohort in Beijing, China. We measured urine specific gravity (USG) to determine the dehydration status, and the concentration of ß2-microglobulin (ß2-MG) and microalbumin (MA) to assess renal function impairment among 1885 children with a mean age of 7.7 years old. The prevalence of dehydration was 61.9%, which was significantly higher in boys (64.3%). Using chi-square tests and linear mixed-effects regression models, we documented the trends of the renal indicators' change over time among different hydration statuses. Compared to Mondays, there were apparent increases of ß2-MG concentrations on Wednesdays (ß = 0.029, p < 0.001) and Fridays (ß = 0.035, p < 0.001) in the dehydrated group, but not in the euhydrated group. As for the MA concentrations, only the decrease on Fridays (ß = -1.822, p = 0.01) was significant in the euhydrated group. An increased trend of elevated ß2-MG concentration was shown in both the euhydrated group (Z = -3.33, p < 0.001) and the dehydrated group (Z = -8.82, p < 0.001). By contrast, there was a decreased trend of elevated MA concentrations in the euhydrated group (Z = 3.59, p < 0.001) but not in the dehydrated group. A new indicator ratio, ß2-MG/MA, validated the consistent trends of renal function impairment in children with dehydration. Renal impairment trends worsened as a function of school days during the week and the dehydration status aggravated renal impairment during childhood across school weekdays, especially tubular abnormalities in children.

Predictors of non-alcoholic fatty liver disease in children.

OBJECTIVE: Abdominal obesity is strongly associated with the development of non-alcoholic fatty liver disease (NAFLD). Early identification and intervention may reduce the risk. We aim to improve pediatric NAFLD screening by comparing discriminative performance of six abdominal obesity indicators. METHODS: We measured anthropometric indicators (waist circumference [WC], waist-to-hip ratio [WHR], waist-to-height ratio [WHtR]), body composition indicators (trunk fat index [TFI], visceral fat area [VFA]), and endocrine indicator (visceral adiposity index [VAI]) among 1350 Chinese children aged 6-8 years. Using Spearman correlation, receiver operating characteristic (ROC) curves, and Logistic regression, we validated their ability to predict NAFLD. RESULTS: All six indicators can predict NAFLD robustly, with area under the curve (AUC) values ranged from 0.69 to 0.96. TFI, WC, and VFA rank in the top three for the discriminative performance. TFI was the best predictor with AUC values of 0.94 (0.92-0.97) and 0.96 (0.92-0.99), corresponding to cut-off values of 1.83 and 2.31 kg/m2 for boys and girls, respectively. Boys with higher TFI (aOR = 13.8), VFA (aOR = 11.1), WHtR (aOR = 3.1), or VAI (aOR = 2.8), and girls with higher TFI (aOR = 21.0) or VFA (aOR = 17.5), were more likely to have NAFLD. CONCLUSION: User-friendly body composition indicators like TFI can identify NAFLD and help prevent the progress of liver disease. TRIAL REGISTRATION: Chinese Clinical Trial Registry (ChiCTR) ( www.chictr.org.cn/enIndex.aspx , No. ChiCTR2100044027); retrospectively registered on 6 March 2021. IMPACT: Abdominal obesity increases the risk of pediatric non-alcoholic fatty liver disease (NAFLD). This study compared the discriminative performance of multiple abdominal obesity indicators measured by different methods in terms of accuracy and fastidious cut-off values through a population-based child cohort. Our results provided solid evidence of abdominal obesity indicators as an optimal screening tool for pediatric NAFLD, with area under the curve (AUC) values ranged from 0.69 to 0.96. User-friendly body composition indicators like TFI show a greater application potential in helping physicians perform easy, reliable, and interpretable weight management to prevent the progress of liver damage.

Sleep disturbances in children newly enrolled in elementary school are associated with parenting stress in China.

OBJECTIVE: This study aimed to investigate the prevalence of children's sleep disturbances among students newly enrolled in elementary school, and explored the association between the two during the child's transition from kindergarten to elementary school. METHODS: In 2019, a cross-sectional study was conducted among 1,510 newly enrolled school kids and their parents in Beijing. Children's sleep characteristics were evaluated using the Children's Sleep Habits Questionnaire (CSHQ), and parenting stress characteristics were assessed with the Parenting Stress Index-Short Form (PSI-SF). Logistic regression models were used to analyze the association between children's sleep and parenting stress. RESULTS: A total of 77.9% of children newly enrolled in elementary school had sleep disturbances and 15.6% of parents had experienced parenting stress. When examining the relationship between children's sleep disturbances and parenting stress, monthly family income over US$1,550 was a protective factor and children with sleep disturbances were associated with higher risk of parenting stress. Two subscales from the CSHQ were associated with higher parenting stress risk: sleep duration and daytime sleepiness. Similarly, parents experiencing parenting stress had children with higher risk of sleep disturbances. This risk was also higher for children from parents screening positive in the PSI-SF subscales for parental distress and difficult child. CONCLUSIONS: We found that children's sleep disturbances and parenting stress were common and there was a bidirectional association between the two during this transition time. Schools and communities need to provide timely psychological support for children and parents to address major stressors.

A multi-center longitudinal study on responsive breastfeeding in China from the perspective of health equity: research protocol.

BACKGROUND: Socio-economic inequities can strongly influence suboptimal infant feeding outcomes. Factors such as lack of knowledge about breastfeeding, low family income, low educational attainment, social and economic status, cultural norms and ethnicity may negatively affect success with offering breastfeeding following a responsive feeding approach (ie. responsive breastfeeding). Such inequities can indeed shorten breastfeeding duration, and negatively affect behavioral and cognitive infant outcomes. In China, there is a dearth of studies focusing on breastfeeding from the responsive and health equity perspective. OBJECTIVE: The aim of this article is to present a protocol of an ongoing longitudinal cohort study investigating factors associated with responsive breastfeeding behaviors, and the child's behavioral and cognitive development from birth to12 months post-partum in five centers in China. The study seeks to identify breastfeeding barriers and facilitators from a health equity perspective. METHODS: We are enrolling 700 women and their singleton full term infants in Chongqing, Huizhou and Guangzhou urban and rural areas. The study questionnaires will be administrated within 72 h, 30 days, 3, 6, 9, and 12 months post-partum during the baby's vaccination visits. We will investigate the difference between urban and rural areas sociodemographic characteristics, breastfeeding knowledge, attitudes and practice, postnatal depression, maternal emotion regulation and parenting stress, and anthropometric and cognitive development indicators of the infants at each time-point. CONCLUSION: Our article illustrates how a cohort study can be designed to understand the barriers and facilitators of responsive breastfeeding taking equity principles into account to help promote infants' growth and development in China.

[Sex difference in height growth and blood pressure change among Beijing school-age children and adolescents: a ten-year longitudinal study].

Objective: To explore sex difference in height growth and blood pressure (BP) change among Beijing school-age children and adolescents. Methods: Using physical examination data of 70 769 school-age children and adolescents from primary to high school during 2009-2018 in Shunyi District, a longitudinal dataset was formed with completed anthropometrical measurements of height and blood pressure (BP) after individual information linkage. Age-specific height, BP, growth rate of height and BP as well BP growth rate based on age at peak height velocity (PHA) were calculated. Linear mixed-effects model was used to identify sex disparity in the growth rates of height and BP. Results: Height and BP increased with age in both boys and girls, and the mean height and BP of boys were always higher than those of girls, except age group from 10 to 11 years. Sex disparity existed in growth rates of height and BP (P<0.001), which was demonstrated by the interaction item of"sex x age"in linear mixed-effects model. The PHA of boys was 12 years old, which was 2 years later than that of girls, about 10 years old. The curves of BP growth rate with age showed double peaks in both boys and girls. Boys reached the peak BP velocity at 13 years old, 3 years lagging behind that of girls who reached the peak at 10 years old. However, the peak of height and BP velocity of boys were higher than that of girls. The change of BP was highly synchronized in time with the increase of height, after adjusting for the growth rate of height by PHA. BP velocity increased with age before onset of puberty till PHA and then declined. Conclusion: Sex disparity in height growth and BP change among school-age children and adolescents is persistent and significant and the change of BP is highly synchronized in time with the increase of height.

[Association of blood pressure and left ventricular mass in children from the PROC cohort study].

Objective: To explore the association between blood pressure (BP) and the left ventricular mass (LVM) in children aged 6-8 years. Methods: The participants were from the community-based census-like design child cohort on sensitization, puberty, obesity and cardiovascular risk (PROC) conducted in six public non-boarding primary schools in Shunyi District, Beijing. Repeated three measurements on anthropometrical, M-mode and 2-dimensional (2D) echocardiographic imaging (2D/M ECHO) and blood biochemical assay, and BP measurements were carried out at baseline and follow-up from October 2018 to June 2019. A total of 1 659 children who had repeated BP measurements and cardiac structure information were included in this study. The average value of last two measurements of BP was determined as BP value for analysis. Formula recommended by Devereux was used to calculate the mass of left ventricle. Robust linear regression models were used to explore the association between BP and LVM in different groups. Results: The average age of all patients was (7.10±0.29) years old, including 832 boys (50.15%). Of all, 83.54% (1 386/1 659) were grouped as normal BP with average LVM (58.54±13.33) g, and 16.46% (273/1 659) as elevated BP group with LVM (63.84±15.78) g (P<0.001). The LVM of the normal BP group was lower than elevated BP group in overall participants, boys and girls (P<0.005). Univariate analysis showed that systolic BP was associated with LVM in overall, boys and girls (P<0.001) respectively. While diastolic BP was associated with LVM in overall and girls (P<0.03). Multivariable analysis indicated that the associations between systolic BP and LVM were observed in overall, boys and girls (P<0.05) with the ß (95%CI)=0.14 (0.08, 0.21), 0.18 (0.08, 0.27) and 0.12 (0.03, 0.22), respectively. However, the associations of diastolic BP and LVM were not significant. Conclusion: Systolic BP is highly associated with LVM and elevated BP could increase the LVM in children. Boys with elevated BP present a larger LVM and might indicate higher risk of left ventricular hypertrophy in adulthood.

[Association between trunk fat index and carotid intima-media thickness among children aged 6-8 years old in Beijing].

Objective: The study is to explore the association between trunk fat index (TFI) and carotid intima-media thickness (cIMT) among children aged 6-8 years old in Shunyi District, Beijing. Methods: The participants were enrolled from the child cohort on sensitization, puberty, obesity and cardiovascular risk (PROC) conducted in Shunyi District, Beijing from October 2018 to June 2019. The PROC used a community-based census-like design, and all eligible first-grade children from six public non-boarding primary schools in urban area were approached. Finally, a total of 1 503 children with written informed consent from parents and had complete data of TFI and cIMT were included for the present study. Sequential baseline surveys including anthropometric measurements, laboratory testing and ultrasonography measurement were conducted to collect the data on height, weight, body composition, blood pressure, serum lipids and cIMT. Linear regression was used to determine the predictors of cIMT, receiver operating characteristic (ROC) curve analysis was used to determine the cut-off value of TFI to identify children with high cIMT, and analysis of covariance was used to evaluate the post-consistency classification of cIMT by TFI. Results: The age of 1 503 participants was (6.7±0.3) years, and 752 boys accounted for 50.0%. The average cIMT was (0.358±0.024) and (0.355±0.023) mm, and the M (P25, P75) of TFI was 0.70 (0.22, 1.78) and 0.74 (0.23, 1.52) kg/m2 for boys and girls, respectively. The detection rates for boys and girls of high cIMT were 2.1% and 3.3%, respectively. Linear regression analysis showed that height, systolic blood pressure (SBP), diastolic blood pressure (DBP), TFI were positively correlated with cIMT in boys (P values<0.05). And height, SBP, triglyceride (TG), TFI were positively correlated with cIMT, and high-density lipoprotein cholesterol (HDL-C) was negatively correlated with cIMT in girls (P values<0.05). ROC curve analysis indicated that the best cut-off values for TFI to identify children with high cIMT were 1.78 and 1.14 kg/m2, at P75 and P66 for boys and girls, respectively. After grouped with the cut-off value of TFI and adjusted for age, height, SBP, DBP, TG, HDL-C, multivariable covariance analysis showed a consistent cut-off of inter-group cIMT mean by TFI groups (P values<0.005). Conclusion: TFI is associated with cIMT, which underscore its application potential in identifying early vascular structural damage.