The current prevalence and regional disparities in general and central obesity among children and adolescents in Shandong, China

Do maternal socioeconomic status influence child overweight?

The prevalence of overweight among Chinese children under 5 years of age has been increasing steadily. Using data from China Health and Nutrition Survey (CHNS) spanning from 1991 to 2015, this study investigates the relationship between maternal employment status, maternal education level, and the prevalence of child overweight among Chinese children under 5 years old. The findings indicate that having mothers with low middle school education significantly reduces their children's body mass index z-scores (BMIZ) (p < 0.05). However, no significant association is observed between maternal education level and childhood overweight in urban areas. In rural areas, only when the maternal education level is college or above, there is a significant increase in BMIZ (p < 0.01). The impact of maternal education level on childhood obesity is influenced by household per capita income, and when household per capita income reaches a certain level, higher maternal education is negatively associated with child BMIZ. The study also reveals a significant negative association between maternal employment (p < 0.01)，average weekly working days (p < 0.01), and the BMIZ of children under 5 years of age, while the interaction effect between them is positive and significant. This study has recommended some policy interventions, by promoting parental education on child feeding and parenting, providing professional child care, and offering financial subsidies to families with children under 5.

Optimal cut-off value of waist circumference-to-height ratio to predict central obesity in children and adolescents: A systematic review and meta-analysis of diagnostic studies

Introduction

Waist circumference-to-height ratio (WHtR) is a simple anthropometric index with good screening power and fast interpretation for early detection of childhood abdominal obesity. This systematic review and meta-analysis aims to determine the best cut-off value of WHtR to use in clinical setting.

Methods

Comprehensive searches were conducted in PubMed, Scopus, and Web of Science by the end of March 2021. Observational studies investigated the best WHtR cut-off to detect abdominal obesity in children and adolescents were included. Thirteen articles (n = 180,119) were included in this systematic review and eight documents were included in the meta-analysis.

Results

The overall optimal cut-off was 0.49 with pooled sensitivity, specificity and diagnostic odds ratio (DOR) of 0.93 (95% confidence interval (CI): 0.93-0.96), 0.88 (95% CI: 0.85-0.91) and 102.6 (95% CI: 50.7-207.5), respectively. The optimal WHtR cut-off to predict abdominal obesity in girls and boys were both 0.49.

Discussion

The current study shows that we could use this cut-off as a simple index for predicting abdominal obesity in children and adolescents without the need for any charts in practice.

Tri-Ponderal Mass Index vs body Mass Index in discriminating central obesity and hypertension in adolescents with overweight

BACKGROUND AND AIMS

Recently, it has been hypothesized that Tri-Ponderal Mass Index (TMI) may be a valid alternative to Body Mass Index (BMI) when measuring body fat in adolescents. We aimed to verify whether TMI has better accuracy than BMI in discriminating central obesity and hypertension in adolescents with overweight.

METHODS AND RESULTS

This monocentric and retrospective cross-sectional study included 3749 pupils, 1889 males and 1860 females, aged 12-13. BMI (kg/m²) was calculated and expressed as percentiles and as z-scores. TMI (kg/m³) was calculated, and we used pre-defined cut-off previously proposed by Peterson et al.. For central obesity we adopted the Waist-to-Height Ratio (WHtR) discriminatory value of 0.5. Hypertension was defined as blood pressure ≥95th percentile of age- sex-, and height-specific references recommended by NHBPEP Working Group. The discriminant ability of TMI, BMI and BMI z-score, with respect to central obesity and hypertension, was investigated using non-parametric receiver operating characteristic analysis. The overall misclassification rate for central obesity was 8.88% for TMI vs 14.10% for BMI percentiles and vs 14.92% for BMI z-scores (P < 0.001). The overall misclassification rate for hypertension was 7.50% for TMI vs 22.03% for BMI percentiles and vs 25.19% for BMI z-scores (P < 0.001).

CONCLUSION

TMI is a superior body fat index and it could discriminate body fat distribution more accurately than BMI. This supports the use of TMI, in association with WHtR, to characterize adolescents with overweight and high cardio-metabolic risk. Our analysis needs to be extended to other ethnic groups and replicated in a wider age range and in longitudinal studies.

Association and potential mediators between socioeconomic status and childhood overweight/obesity

The associations between socioeconomic status and childhood overweight/obesity are inconsistent, and potential underlying factors are unclear. In China, Hukou status is an important attribute of individual's socioeconomic circumstances, but previously received less consideration as a socioeconomic indicator. This study aimed to investigate the association between comprehensive socioeconomic status and childhood overweight/obesity. Using data from Wuhan Maternal and Child Health Management Information System (2009-2018, N = 209,500), clustering analysis was used to create comprehensive socioeconomic groups with indicator components such as parental education level, occupation, and maternal Hukou. The associations between the determined socioeconomic status and childhood overweight/obesity at age 1 and 2 were examined by log-binomial model. Parallel and serial mediation analyses were performed to test the indirect effects of potential mediators, including maternal pre-pregnancy body mass index, gestational weight gain, and infant birth weight, in the association between socioeconomic status and childhood overweight/obesity. Four clusters, defined as low, low-medium, medium-high, and high socioeconomic groups, were identified through clustering analysis. Hukou, among five socioeconomic components, contributed the most to the development of childhood overweight/obesity. Children in the low-medium socioeconomic group have a greater risk of overweight/obesity than the low socioeconomic group. Indirect effects of maternal pre-pregnancy body mass index, gestational weight gain, and infant birth weight were identified for the association. In conclusion, socioeconomic status may impact childhood obesity through maternal pre-pregnancy body mass index, gestational weight gain, and infant birth weight. Hukou should be considered in the evaluation of socioeconomic status in China.

Effects of Vitamin D Supplementation on General and Central Obesity: Results from 20 Randomized Controlled Trials Involving Apparently Healthy Populations

Background: The obesity pandemic has been paralleled by a high prevalence of vitamin D deficiency (VDD). There is growing epidemiological evidence linking low vitamin D status with obesity events. In addition, observational studies also show that obesity may increase the risk of VDD. However, there is insufficient knowledge to understand whether there is a causality between the two. Moreover, the impact of vitamin D supplementation on obesity indices has shown inconsistent outcomes. Objective: This meta-analysis aimed to assess whether vitamin D supplementation modified general and central obesity indices in apparently healthy populations. Methods: A systematic retrieval of relevant randomized controlled trials (RCTs) was undertaken using Pubmed, Embase, Web of Knowledge and Chinese National Knowledge Infrastructure databases. The pooled weighted mean difference (WMD) and 95% confidence intervals (CI) were used to assess the changes in body mass index (BMI), waist circumference (WC), waist-to-hip ratio (WHR) and 25-hydroxyvitamin D (25[OH]D) from baseline. Results: Twenty RCTs involving 3,153 participants reporting either BMI, WC, WHR or 25(OH)D met the inclusion criteria. When compared with placebo, vitamin D supplementation had no significant decreases in BMI (WMD = –0.09 kg/m2, 95% CI –0.19 to 0.01, p = 0.08), WC (WMD = –0.71 cm, 95% CI –1.58 to 0.16, p = 0.112) or WHR (WMD = 0.00, 95% CI –0.01 to 0.01, p = 0.749). However, in the subgroups of females, Asia region studies and intervention duration ≥6 months, a beneficial and significant reduction in BMI and WC was noted (all p < 0.026). On the other hand, pooled results showed that there was a significant increase in serum 25(OH)D levels (WMD = 13.20 ng/mL, 95% CI 9.83–16.58, p < 0.001) after vitamin D intervention. No publication bias was found in our study. Conclusions: Overall, supplementation with vitamin D produced no significant effect on the BMI, WC or WHR of healthy adults.

Impact of obese levels on the hepatic expression of nuclear receptors and drug-metabolizing enzymes in adult and offspring mice

The prevalence of obesity-associated conditions raises new challenges in clinical medication. Although altered expression of drug-metabolizing enzymes (DMEs) has been shown in obesity, the impacts of obese levels (overweight, obesity, and severe obesity) on the expression of DMEs have not been elucidated. Especially, limited information is available on whether parental obese levels affect ontogenic expression of DMEs in children. Here, a high-fat diet (HFD) and three feeding durations were used to mimic different obese levels in C57BL/6 mice. The hepatic expression of five nuclear receptors (NRs) and nine DMEs was examined. In general, a trend of induced expression of NRs and DMEs (except for Cyp2c29 and 3a11) was observed in HFD groups compared to low-fat diet (LFD) groups. Differential effects of HFD on the hepatic expression of DMEs were found in adult mice at different obese levels. Family-based dietary style of an HFD altered the ontogenic expression of DMEs in the offspring older than 15 days. Furthermore, obese levels of parental mice affected the hepatic expression of DMEs in offspring. Overall, the results indicate that obese levels affected expression of the DMEs in adult individuals and that of their children. Drug dosage might need to be optimized based on the obese levels.

Childhood obesity in New Zealand

BACKGROUND

Paediatric obesity has reached epidemic proportions globally, resulting in significant adverse effects on health and wellbeing. Early life events, including those that happen before, during, and after pregnancy can predispose children to later obesity. The purpose of this review is to examine the magnitude of obesity among New Zealand children and adolescents, and to determine their underlying risk factors and associated comorbidities.

DATA SOURCES

PubMed, Web of Science, and Google Scholar searches were performed using the key terms "obesity", "overweight", "children", "adolescents", and "New Zealand".

RESULTS

Obesity is a major public health concern in New Zealand, with more than 33% of children and adolescents aged 2-14 years being overweight or obese. Obesity disproportionately affects Māori (New Zealand's indigenous population) and Pacific children and adolescents, as well as those of lower socioeconomic status. New Zealand's obesity epidemic is associated with numerous health issues, including cardiometabolic, gastrointestinal, and psychological problems, which also disproportionately affect Māori and Pacific children and adolescents. Notably, a number of factors may be useful to identify those at increased risk (such as demographic and anthropometric characteristics) and inform possible interventions.

CONCLUSIONS

The prevalence of overweight and obese children and adolescents in New Zealand is markedly high, with a greater impact on particular ethnicities and those of lower socioeconomic status. Alleviating the current burden of pediatric obesity should be a key priority for New Zealand, for the benefit of both current and subsequent generations. Future strategies should focus on obesity prevention, particularly starting at a young age and targeting those at greatest risk.

Sex Differences in the Relation between Waist Circumference within the Normal Range and Development of Reflux Esophagitis

We examined the association of abdominal obesity and waist circumference within normal range with the incidence of reflux esophagitis, separately in men and women. This cohort study involved 142,679 Korean adults without reflux esophagitis, who underwent upper endoscopy at baseline and during follow-up. Waist circumference was categorized into the following quartiles: <80, 80.1⁻85, 85.1⁻90, and ≥90.1 cm in men; and <69.3, 69.3⁻74, 74.1⁻79.5, and ≥79.6 cm in women. During the 551,877.8 person-years of follow-up, 29,509 participants developed reflux esophagitis. The association between waist circumference quartiles and risk of reflux esophagitis significantly differed with sex (p for interaction < 0.001). In men, multivariable-adjusted hazard ratios (HRs) (95% confidence intervals (CIs)) comparing waist circumference quartiles 2, 3, and 4 to the lowest quartile were 1.03 (0.99⁻1.07), 1.08 (1.04⁻1.12), and 1.15 (1.10⁻1.19), respectively. In women, HRs (95% CIs) comparing quartiles 1, 2, and 4 to the 3rd quartile were 1.10 (1.04⁻1.17), 1.03 (0.98⁻1.10), and 1.07 (1.01⁻1.13), respectively. In this large cohort with endoscopic follow-up, the risk of reflux esophagitis increased with increasing waist circumference even within the normal range in men, whereas the risk increased with low normal waist circumference or with abdominal obesity in women, indicating a U-shaped association.

Mid-Upper-Arm Circumference and Arm-to-Height Ratio to Identify Obesity in School-Age Children

BACKGROUND

In resource-poor settings, anthropometric parameters are evaluated as potential alternatives to the body mass index (BMI) for detecting overweight and obesity in children. To this end, the mid-upper-arm circumference (MUAC) and the mid-upper-arm circumference-to-height ratio (AHtR) were evaluated as proxies to BMI in Thai school-age children.

STUDY DESIGN

An observational, cross-sectional study was performed on school-aged children.

PARTICIPANTS

Children in grades 1 through 6 at all public elementary schools in the Ongkharak district, Nakhon Nayok, Thailand during May and June 2013 were included. This is a rural district with low per capita income.

METHODS

Weight, height, and MUAC were measured in school-age children and analyzed to identify optimal cut-off values for MUAC and AHtR for detection of overweight and obesity in comparison to BMI. Receiver operating characteristic (ROC) curve analysis determined the validity of MUAC and AHtR use.

RESULTS

Data from 3,618 children, aged 6.0-12.99 years, were analyzed. MUAC correlated with age and height (P < 0.001), but especially with body weight (r = 0.888 to 0.914) and BMI (r = 0.859 to 0.908) in both genders, while AHtR correlated with body weight and BMI (P < 0.001), but not with age. Cut-off values of MUAC for obesity diagnosis ranged from 18.9 to 25.5 cm for boys and from 19.8 to 25.4 cm for girls. Accuracy was excellent for both boys (AUC = 0.952-0.991) and girls (AUC = 0.917-0.990). Cut-off of MUAC for overweight diagnosis ranged from 17.2 to 22.4 cm for boys (AUC = 0.883-0.965) and from 18.0 to 23.2 cm for girls (AUC = 0.905-0.931). AHtR cut-off values for obesity and overweight diagnosis at 0.16 and 0.145, respectively, were determined with excellent diagnostic accuracy (AUC ranged from 0.920 to 0.975).

CONCLUSION

MUAC and AHtR were reliable tools to detect overweight and obesity in Thai school-age children. Cut-off points for MUAC were age and gender specific, while AHtR at 0.16 and 0.145 were the optimal values for both genders, independent of age. These anthropometric measurements showed excellent accuracy in predicting overweight and obesity with high specificity and sensitivity.

Ethical issues in obesity prevention for school children: a systematic qualitative review

OBJECTIVES

Planning and conducting preventive measures against obesity for school children is beset with ethical issues which should be known to make well-informed decisions. The goal of this study was to provide a comprehensive spectrum of these ethical issues by means of a systematic review. In this context, the study also assesses the value of different search strategies for ethical literature in public health.

METHODS

Literature was searched in Medline, EBSCO and others. Three different search strategies with varied scopes were applied and their output was compared. Qualitative content analysis was used for extracting and categorizing ethical issues.

RESULTS

109 publications (published from 1995 to 2015) were finally included. The qualitative analysis resulted in 60 potentially relevant ethical issues. The three search strategies showed substantial differences regarding their search results.

CONCLUSIONS

The presented spectrum provides an initial evidence base for dealing with ethical issues adequately. The findings of the study further suggest that a broader scope is more fruitful for systematic reviews on ethical issues in the field of public health.