Childhood obesity: are genetic differences involved?

Paternal obesity induces subfertility in male offspring by modulating the oxidative stress-related transcriptional network

BACKGROUND/OBJECTIVE

The effects of fathers' high-fat diet (HFD) on the reproductive health of their male offspring (HFD- F1) remain to be elucidated. Parental obesity is known to have a negative effect on offspring fertility, but there are few relevant studies on the effects of HFD-F1 on reproductive function.

METHODS

We first succeeded in establishing the HFD model, which provides a scientific basis in the analysis of HFD-F1 reproductive health. Next, we assessed biometric indices, intratesticular cellular status, seminiferous tubules and testicular transcriptomic homeostasis in HFD-F1. Finally, we examined epididymal (sperm-containing) apoptosis, as well as antioxidant properties, motility, plasma membrane oxidation, DNA damage, and sperm-egg binding in the epididymal sperm.

RESULTS

Our initial results showed that HFD-F1 mice had characteristics similar to individuals with obesity, including higher body weight and altered organ size. Despite no major changes in the types of testicular cells, we found decreased activity of important genes and noticed the presence of abnormally shaped sperm at seminiferous tubule lumen. Further analysis of HFD-F1 testes suggests that these changes might be caused by increased vulnerability to oxidative stress. Finally, we measured several sperm parameters, these results presented HFD-F1 offspring exhibited a deficiency in antioxidant properties, resulting in damaged sperm mitochondrial membrane potential, insufficient ATP content, increased DNA fragmentation, heightened plasma membrane oxidation, apoptosis-prone and decreased capacity for sperm-oocyte binding during fertilization.

CONCLUSION

HFD- F1 subfertility arises from the susceptibility of the transcriptional network to oxidative stress, resulting in reduced antioxidant properties, motility, sperm-egg binding, and elevated DNA damage. Schematic representation of the HFD-F1 oxidative stress susceptibility to subfertility. Notably, excessive accumulation of ROS surpasses the physiological threshold, thereby damaging PUFAs within the sperm plasma membrane. This oxidative assault affects crucial components such as mitochondria and DNA. Consequently, the sperm's antioxidant defense mechanisms become compromised, leading to a decline in vitality, motility, and fertility.

3D genomic features across >50 diverse cell types reveal insights into the genomic architecture of childhood obesity

The prevalence of childhood obesity is increasing worldwide, along with the associated common comorbidities of type 2 diabetes and cardiovascular disease in later life. Motivated by evidence for a strong genetic component, our prior genome-wide association study (GWAS) efforts for childhood obesity revealed 19 independent signals for the trait; however, the mechanism of action of these loci remains to be elucidated. To molecularly characterize these childhood obesity loci we sought to determine the underlying causal variants and the corresponding effector genes within diverse cellular contexts. Integrating childhood obesity GWAS summary statistics with our existing 3D genomic datasets for 57 human cell types, consisting of high-resolution promoter-focused Capture-C/Hi-C, ATAC-seq, and RNA-seq, we applied stratified LD score regression and calculated the proportion of genome-wide SNP heritability attributable to cell type-specific features, revealing pancreatic alpha cell enrichment as the most statistically significant. Subsequent chromatin contact-based fine-mapping was carried out for genome-wide significant childhood obesity loci and their linkage disequilibrium proxies to implicate effector genes, yielded the most abundant number of candidate variants and target genes at the BDNF, ADCY3, TMEM18 and FTO loci in skeletal muscle myotubes and the pancreatic beta-cell line, EndoC-BH1. One novel implicated effector gene, ALKAL2 - an inflammation-responsive gene in nerve nociceptors - was observed at the key TMEM18 locus across multiple immune cell types. Interestingly, this observation was also supported through colocalization analysis using expression quantitative trait loci (eQTL) derived from the Genotype-Tissue Expression (GTEx) dataset, supporting an inflammatory and neurologic component to the pathogenesis of childhood obesity. Our comprehensive appraisal of 3D genomic datasets generated in a myriad of different cell types provides genomic insights into pediatric obesity pathogenesis.

Shared correlates of maternal and childhood overweight in Cameroon: a cross-sectional analysis of demographic and health survey data

BACKGROUND

Overweight parents are likelier to bear overweight babies, who are likelier to grow into overweight adults. Understanding the shared risks of being overweight between the mother-child dyad is essential for targeted life course interventions. In this study, we aimed to identify such risk factors in Cameroon.

METHODS

We conducted secondary data analysis using Cameroon's 2018 Demographic and Health Surveys. We used weighted multilevel binary logistic regressions to examine individual, household, and community correlates of maternal (15-49 years) and child (under five years) overweight.

RESULTS

We retained 4511 complete records for childhood and 4644 for maternal analysis. We found that 37% [95%CI:36-38%] of mothers and 12% [95%CI:11-13%] of children were overweight or obese. Many environmental and sociodemographic factors were positively associated with maternal overweight, namely urban residence, wealthier households, higher education, parity and being a Christian. Childhood overweight was positively associated with a child being older and a mother being overweight, a worker, or a Christian. Therefore, only religion affected both mothers overweight (aOR: 0.71[95%CI:0.56-0.91]) and childhood overweight (aOR 0.67[95%CI: 0.5-0.91]). Most of the potentially shared factors only indirectly affected childhood overweight through maternal overweight.

CONCLUSION

Besides religion, which affects both mothers and childhood overweight (with the Muslim faith being protective), much of childhood overweight is not directly explained by many of the observed determinants of maternal overweight. These determinants are likely to influence childhood overweight indirectly through maternal overweight. Extending this analysis to include unobserved correlates such as physical activity, dietary, and genetic characteristics would produce a more comprehensive picture of shared mother-child overweight correlates.

Process and effect evaluation of the app-based parenting program Samen Happie! on infant zBMI: A randomized controlled trial

Background

Although energy balance-related parenting practices are regarded critical components in the prevention of childhood obesity, most programs targeting parenting practices with respect to a wide range of energy balance-related behaviors were not aimed at high-risk families with a lower socioeconomic position (SEP).

Objective

The Samen Happie! app-based program aimed to stimulate healthy child weight development especially among families with a lower SEP, by encouraging healthy energy balance-related parenting practices.

Methods

A two-armed randomized controlled trial examined the process and effectiveness of the Samen Happie! program on child zBMI outcomes at 6- and 12-months follow-up. In total, 357 Dutch parents with infants aged 5-15 months old at baseline participated. Parents in the app condition (n = 179) received access to the Samen Happie! app and were compared to a waitlist-control condition (n = 178). Changes in zBMI were examined through linear mixed-effects models based on intention-to-treat and exploratory per-protocol principles.

Results

Process data showed low levels of sustained app use and moderate app acceptability. A general increase in child zBMI was observed in both conditions after 6 and 12 months. Intention-to-treat analyses using multiple imputations showed several statistically significant differences between conditions and high-risk subgroups. Specifically, at 6-months follow-up, zBMI increase was least pronounced in the app condition among children of parents with lower educational level. These findings were supported by exploratory per-protocol analyses including only frequent app users. In addition, per-protocol analyses showed benefits of app use at 6-months follow-up for children of parents with higher BMI. However, these effects were reversed at 12-months follow-up in both intention-to-treat and per-protocol analyses, where children of parents in the app condition in general increased the most in zBMI.

Conclusions

This study suggests that the Samen Happie! program might prevent zBMI increases after 6 months among children of parents with lower educational level, and children of parents with higher BMI who more frequently use the app. However, the app did not prevent increases in zBMI after 12 months. Future research should investigate strategies to increase sustained app use and engagement in mHealth parenting programs for childhood obesity as well as options to combine app-based programs with additional support strategies aimed at high-risk families.

Trial registration

Netherlands trial register (ID: NTR6938), https://trialsearch.who.int/Trial2.aspx?TrialID=NTR6938.

The Role of Molecular and Hormonal Factors in Obesity and the Effects of Physical Activity in Children

Obesity and overweight are defined as abnormal fat accumulations. Adipose tissue consists of more than merely adipocytes; each adipocyte is closely coupled with the extracellular matrix. Adipose tissue stores excess energy through expansion. Obesity is caused by the abnormal expansion of adipose tissue as a result of adipocyte hypertrophy and hyperplasia. The process of obesity is controlled by several molecules, such as integrins, kindlins, or matrix metalloproteinases. In children with obesity, metabolomics studies have provided insight into the existence of unique metabolic profiles. As a result of low-grade inflammation in the system, abnormalities were observed in several metabolites associated with lipid, carbohydrate, and amino acid pathways. In addition, obesity and related hormones, such as leptin, play an instrumental role in regulating food intake and contributing to childhood obesity. The World Health Organization states that physical activity benefits the heart, the body, and the mind. Several noncommunicable diseases, such as cardiovascular disease, cancer, and diabetes, can be prevented and managed through physical activity. In this work, we reviewed pediatric studies that examined the molecular and hormonal control of obesity and the influence of physical activity on children with obesity or overweight. The purpose of this review was to examine some orchestrators involved in this disease and how they are related to pediatric populations. A larger number of randomized clinical trials with larger sample sizes and long-term studies could lead to the discovery of new key molecules as well as the detection of significant factors in the coming years. In order to improve the health of the pediatric population, omics analyses and machine learning techniques can be combined in order to improve treatment decisions.

Prevalence and Associated Risk Factors of Childhood Obesity in the Eastern Province of Saudi Arabia

Introduction Overweight and obesity are defined as excessive fat accumulation that poses a risk to well-being. In children, a BMI of the 85th percentile to less than the 95th percentile is considered overweight, and the 95th percentile or greater is considered obese. Aim This study aimed to measure the prevalence of childhood obesity in a population of six to 16 years of age and its associated risk factors. Participants and methods This is a cross-sectional study conducted among children aged between six and 16 years old who live in the Eastern province of Saudi Arabia. The data collector in each school distributed envelopes containing an informed consent form and a survey to collect data on the demographics and socioeconomic status to all students. All students whose parents signed the informed consent would undergo measurement of growth parameters which ultimately determined the BMI. Results Six hundred eighty-eight children agreed to participate. The prevalence of overweight and obesity was 15.3% (overweight 10.2%, obese 5.1%). Children who eat four or more meals per day were 29.5% while only 10% were regularly exercising for more than two hours a day. Independent risk factors of obesity and overweight were eating four or more meals per day. Spending more than an hour a day on physical activity was a protective factor against being overweight and obese. Conclusion Increased daily food consumption was the most frequent risk factor for obesity. Physical activity was the protective factor against obesity in children and adolescents. Further intervention measures must be implemented to reduce the prevalence of overweight and obesity. A healthy lifestyle based on effective dietary education and physical activity promotion is required to prevent overweight and obesity among youth.

Comparison of the key modifiable factors in the first 1000 days predicting subsequent overweight and obesity in pre-school children in Tehran: a case-control study

The identification of paediatric obesity predictors in the early stages of life is warranted, as it can influence the development of effective strategies to prevent metabolic disorders. In this case-control study, we assessed nine risk factors for paediatric obesity, namely a birth weight > 4000 g, an exclusive breast-feeding period < 4 months, the introduction of solid food at < 4 months, maternal overweight or obesity before pregnancy, maternal smoking during pregnancy, the presence of gestational diabetes, paternal overweight and obesity and paternal smoking. In order to identify the most relevant predictors of paediatric obesity, we employed a multiple logistic regression model with R2 Cox Snell by adjusting confounders. In the randomly selected 509 preschool children from Tehran, children exposed to gestational diabetes had the maximum predicted probability of obesity (4·36 (1·94, 9·80) %) among the analysed risk factors %. The introduction of solid food at < 4 months of age increased the risk of obesity by 2·98 (1·77, 4·97 %). The OR of childhood obesity was associated with maternal overweight and obesity (2·72(1·60-4·60) %), maternal smoking (2·21 (1·18, 4·11) %) and excessive gestational weight gain (1·89 (1·23, 2·91) %). Paternal smoking and high birth weight increased the risk of paediatrics obesity > 1·8 times (1·15-2·94) and > 1·5 times (1·015-2·43), respectively. There was no association between the paternal BMI, the exclusive breast-feeding time and the risk of paediatric obesity. Among early risk factors, probably gestational diabetes can be considered as the most important predictor for the risk of paediatric obesity.

Effects of a maternal high-fat diet on adipose tissue in murine offspring: A systematic review and meta-analysis

The aim of this systematic review and meta-analysis was to analyze the influence of a maternal and/or offspring high-fat diet (HFD) on the morphology of the offspring adipocytes and amount of food and energy consumption. The search was conducted through Pubmed, EMBASE, and Web of Science databases up to October 31st, 2021. The outcomes were extracted and pooled as a standardized mean difference with random effect models. 5,004 articles were found in the databases. Of these, only 31 were selected for this systematic review and 21 were included in the meta-analysis. A large discrepancy in the percentage of fat composing the HFD (from 14% to 62% fat content) was observed. Considering the increase of adipose tissue by hyperplasia (cell number increase) and hypertrophy (cell size increase) in HFD models, the meta-analysis showed that excessive consumption of a maternal HFD influences the development of visceral white adipose tissue in offspring, related to adipocyte hypertrophy, regardless of their HFD or control diet consumption. Upon following a long-term HFD, hyperplasia was confirmed in the offspring. When analyzing the secondary outcome in terms of the amount of food and energy consumed, there was an increase of caloric intake in the offspring fed with HFD whose mothers consumed HFD. Furthermore, the adipocyte hypertrophy in different regions of the adipose tissue is related to the sex of the pups. Thus, the adipose tissue obesity phenotypes in offspring are programmed by maternal consumption of a high-fat diet, independent of postnatal diet.

Resource mobilization combined with motivational interviewing to promote healthy behaviors and healthy weight in low-income families: An intervention feasibility study

Objectives:

This non-randomized pilot trial examined the feasibility and acceptability of an intervention for low-income families with one parent with obesity, glucose intolerance and/or diabetes.

Methods:

The 12-month intervention combined health coaching using motivational interviewing to promote lifestyle behavior change and community resource mobilization to assist with basic needs plus diet quality and physical activity. Outcome measures included process measures, open-ended questions, and the Family Nutrition and Physical Activity scale.

Results:

Forty-five families completed an average of 2.1 health coach in-person visits, including 15 families lost to follow-up. Parents who stayed in the intervention reported the intervention was helpful. Some families and the health coach had difficulties contacting one another, and some of these families reported they would have liked more sessions with the coach. The Family Nutrition and Physical Activity scores improved significantly for all children (6 months: 2.9; p < .01; 12 months: 3.2; p < .05) and at 6 months for index children (6 months: 3.5; p < .01; 12 months: 2.9; p = .09). There was variation in the FNPA and other outcome changes between families.

Conclusion:

This intervention was feasible in terms of recruitment and delivery of family sessions and community referrals and acceptable to participants, but maintaining contact with participants was difficult. Findings warrant improvements to help retention and logistical aspects of communication between families and coaches and testing in a randomized, controlled trial.

Multigenerational transmission of obesity: A systematic review and meta-analysis

There is a strong link between parental and offspring obesity status. However, the state of epidemiological evidence on multigenerational transmission of overweight/obesity, such as from grandparents to grandchildren, is relatively unknown. This systematic review collates and appraises existing evidence on multigenerational transmission of overweight/obesity and uses meta-analytic estimates for quantitative synthesis. Six electronic databases were searched for publications reporting the relationship between grandparents and their grandchildren overweight/obesity status. A total of 25 studies from 17 countries with a combined population of 238,771 study participants met the inclusion criteria. About 60% (15) of the reviewed studies reported a positive association between grandparent-grandchild (GP-GC) overweight/obesity, out of which 11 were statistically significant. Seven studies reported odds ratios of GP-GC overweight/obesity associations and were included in the meta-analysis. The pooled estimates showed a significant GP-GC association in overweight/obesity status (odds ratio [OR]: 1.79, 95% confidence interval [CI]: 1.01-2.57). Thus, the current research evidence shows that grandchildren's overweight/obesity status is associated with their grandparents' overweight/obesity status, indicating a multigenerational transmission of obesity. However, more studies, especially from developing countries, are required to assess the robustness of these findings. Future studies should also focus on the mechanisms through which this transmission occurs.

The Effect of Polymorphisms of Energy Metabolism Genes on Metabolic Disorders in Overweight Adolescents of Two Ethnicities

The aim of this cross-sectional observational study is to determine the contribution of polymorphisms of energy metabolism genes into metabolic disorders in Russian and Buryat adolescents with overweight and obesity. The study included 354 Russian and Buryat adolescents aged 13-18 years. Body mass index and serum levels of glucose, insulin, and leptin were measured and insulin resistance index HOMA-IR was calculated. Molecular genetic analysis for the presence of 9 loci of energy metabolism genes LEP, LEPR, POMC, FTO, and MC4R were analyzed. It was found that the risk of metabolic disorders is associated with the presence of polymorphic loci of leptin receptor gene LEPR and melanocortin receptor gene MC4R (LEPR rs1137100+LEPR rs1137101 and LEPR rs1137100+MC4R rs17782313) in Russian adolescents with overweight and obesity and polymorphisms of the gene FTO (FTO rs9939609+rs8050136) associated with fat mass and obesity in Buryat adolescents.

A randomized controlled trial of a community-based obesity intervention utilizing motivational interviewing and community resource mobilization for low-income families: Study protocol and baseline characteristics

Low-income, racially diverse families with one parent with obesity are at high risk for child obesity. Effective approaches to promote healthy behaviors and prevent additional weight gain in family members are needed. Motivational interviewing (MI) may assist families to engage, identify motivations for change and establish goals. However, families with limited resources face other barriers to goal achievement that may be addressed through connection with community organizations. This paper describes a unique protocol combining MI and community connection. This randomized controlled trial includes low-income families with one parent with obesity and at least one child aged 6 to 12 years. Families in the intervention group receive an innovative, 12-month intervention combining health coaching using MI to promote lifestyle behavior change goals and community resource mobilization to assist with basic needs and resources to aid goals. The study protocol is modeled on community-based participatory research principles. Data is collected at baseline, 6 months, 12 months, and 18 months include questionnaires, body measurements, and accelerometer data. For adults, primary outcomes are Body Mass Index (BMI), minutes of moderate to vigorous physical activity (MVPA), and hours of sedentary time per day. For children, primary outcomes are sedentary time, MVPA, and the Family Nutrition and Physical Activity Score. From this hard-to-reach population, 236 diverse families were recruited. If the study is deemed effective, it has the potential to demonstrate that the combination of MI, resource mobilization, and utilization of existing community organizations is a sustainable model to assist families at risk for obesity.

Sex differences in metabolically healthy and metabolically unhealthy obesity among Chinese children and adolescents

OBJECTIVES

To analyze sex differences in the prevalence of obesity phenotypes and their risk factors among children and adolescents aged 7-18 years in China.

METHODS

We enrolled 15,114 children and adolescents aged 7-18 years into the final analysis. Obesity phenotypes were classified by body mass index (BMI) and metabolic status as metabolically healthy or unhealthy obesity. In addition, we collected four possible influencing factors on obesity phenotypes through questionnaires, including demographic, parental, early life, and lifestyle indicators. Multinomial logistic regression analysis in a generalized linear mixed model (GLMM) was selected to estimate the odds ratio (OR) and 95% confidence interval (95% CI) for identifying risk factors and control the cluster effects of schools. More importantly, the interaction terms of sex and each indicator were established to demonstrate the sex differences.

RESULTS

The prevalence of metabolically healthy obesity (MHO), metabolically unhealthy obesity (MUO), metabolically healthy overweight and obesity (MHOO), and metabolically unhealthy overweight and obesity (MUOO) were 3.5%, 5.6%, 11.1%, and 13.0% respectively, with higher prevalence in boys (5.3% vs. 1.6%, 7.9% vs. 3.1%, 14.3% vs. 7.7%, 15.6% vs. 10.1%). In addition, younger ages, single children, parental smoking, parental history of diseases (overweight, hypertension, diabetes), caesarean, premature, and delayed delivery time, high birth weight, insufficient sleep time, and excessive screen time were considered as important risk factors of MHO and MUO among children and adolescents (p < 0.05). More notably, boys were at higher risks of MUO when they were single children (boys: OR = 1.56, 95% CI: 1.24-1.96; girls: OR = 1.12, 95% CI: 0.82-1.54), while girls were more sensitive to MUO with parental smoking (girls: OR = 1.34, 95% CI: 1.02-1.76; boys: OR = 1.16, 95% CI: 0.97-1.39), premature delivery (girls: OR = 3.11, 95% CI: 1.59-6.07; boys: OR = 1.22, 95% CI: 0.67-2.22), high birth weight (girls: OR = 2.45, 95% CI: 1.63-3.69; boys: OR = 1.28, 95% CI: 0.96-1.70), and excessive screen time (girls: OR = 1.47, 95% CI: 1.06-2.04; boys: OR = 0.97, 95% CI: 0.79-1.20), with significant interaction term for sex difference (p_interaction < 0.05).

CONCLUSIONS

MHO and MUO are becoming prevalent among Chinese children and adolescents. Significant sex differences in the prevalence of obesity phenotypes as well as their environmental and genetic risk factors suggest it might be necessary to manage obesity phenotypes problems from a sex perspective.

Effects of Paternal Obesity on Fetal Development and Pregnancy Complications: A Prospective Clinical Cohort Study

OBJECTIVES

To evaluate the association between paternal obesity and fetal development and pregnancy complications.

STUDY DESIGN

This prospective cohort clinical trial analyzed data from 7683 women with singleton pregnancies. All study subjects were sequentially divided into four groups based on paternal BMI. We compared the differences in fetal growth and pregnancy complications between different paternal BMI groups by univariate logistic regression and independent t-test. Finally, the independent predictors of SGA and macrosomia were determined.

RESULTS

The incidences of preeclampsia, cesarean section, SGA, macrosomia, and postpartum hemorrhage in the paternal obesity group were significantly higher than the normal BMI group. With the increase of paternal BMI, fetal ultrasound measurement parameter, neonatal and placental weight showed an increasing trend (trend P < 0.05). However, these differences disappeared in the obese group. The test for interaction showed the effect of paternal obesity on SGA and macrosomia was significantly affected by maternal obesity. We also found paternal obesity was an independent predictor of both SGA and macrosomia. Based on the above results, we plotted the Nomograms for clinical prediction.

CONCLUSION

Paternal obesity can affect fetal growth parameters and placental development, which has an adverse impact on pregnancy outcomes. Optimizing the paternal BMI will help improve the health of the next generation.

Exposure to maternal hyperglycemia and high-fat diet consumption after weaning in rats: repercussions on periovarian adipose tissue

Clinical and epidemiological studies show that maternal hyperglycemia can change the programming of offspring leading to transgenerational effects. These changes may be related to environmental factors, such as high-fat diet (HFD) consumption, and contribute to the comorbidity onset at the adulthood of the offspring. The objective of this study was to evaluate the hyperglycemic intrauterine environment, associated or not with an HFD administered from weaning to adult life on the periovarian adipose tissue of rat offspring Maternal diabetes was chemically induced by Streptozotocin. Female offsprings were randomly distributed into four experimental groups (n = 5 animals/group): Female offspring from control or diabetic mothers and fed an HFD or standard diet. HFD was prepared with lard enrichment and given from weaning to adulthood. On day 120 of life, the rats were anesthetized and sacrificed to obtain adipose tissue samples. Then, the hyperglycemic intrauterine environment and HFD fed after weaning caused a higher body weight, total fat, and periovarian fat in adult offspring, which could compromise the future reproductive function of these females. These rats showed higher adiposity index and adipocyte area, contributing to hypertrophied adipose tissue. Therefore, maternal diabetes itself causes intergenerational changes and, in association with the HFD consumption after weaning, exacerbated the changes in the adipose tissue of adult female offspring.

The Incidence of Adult Obesity is Associated with Parental and Adolescent Histories of Obesity in North Sumatra, Indonesia: A Cross-Sectional Study

Purpose

Obesity that occurs in adulthood is influenced by various factors, not only energy balance, especially concerning the amount of energy consumed, but also heredity. The hereditary factors of obese parents on childhood obesity have been studied, but what about adulthood? This study examines the relationship between a history of obesity in adolescence, and maternal and paternal incidences of adult obesity.

Patients and Methods

This study was a cross-sectional study that included adult men and women aged 20–60 years old. The subjects had no chronic or metabolic disease. This research was conducted from April to November, 2020, in North Sumatra Province, Indonesia. The parameters studied were demographics, daily food intake, anthropometry and a history of obesity in adolescence, and for the participants’ fathers and mothers. The statistical test used was the chi-squared test/Fisher test.

Results

This study included 136 research subjects, 60 male and 76 female; based on the results of the study, 47.8% were found to be obese, but food intake showed a low intake (96.2%). There was a significant relationship between a history of obesity in adolescence and incidences of obesity (≥30 kg/m²) in the mother and father, with significance values of p=0.01, p=0.004, and p=0.001, respectively.

Conclusion

This study found that there was a significant relationship between a history of obesity in adolescence and incidences of adult obesity (≥ 30kg/m²) in parents, but not with the level of food intake per day. The risk of obesity will increase further with a history of obesity in parents and obesity in adolescence, and this can be used to understand and prevent obesity.

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Modifiable Early Childhood Risk Factors for Obesity at Age Four Years

Background: Childhood obesity is associated with an increased risk of adult obesity and related chronic disease. Our aim was to identify modifiable exposures that are independently associated with obesity in the preschool age group. Methods: A prospective cohort study of 5734 children in New Zealand with anthropometric measurements was completed at age 4.5 years. The modifiable exposures of interest, measured at age 9 months and 2 years, were: food security during infancy; and, at age 2 years, screen time; sleep duration; and takeaway food and soft drink intake. The risk of obesity independently associated with each exposure was determined using Binomial and Poisson regression and described using adjusted risk ratios (RRs) and 95% confidence intervals (CIs), after controlling for confounding variables including gender, ethnicity, birth weight, and mother's age. The probability of obesity given cumulative exposures to the four risk factors and the population attributable fraction (PAF) were estimated. Results: Lower food security during infancy (<mean study sample score; RR = 1.32; 95% CI : 1.06-1.64) and, at age 2 years, more screen time (>1 hour/day; RR = 1.22; 95% CI : 1.01-1.48), shorter sleep duration (≤11.5 hours/day; RR = 1.30; 95% CI : 1.05-1.61), and weekly to daily consumption of takeaway/soft drink (RR = 1.25, 95% CI : 1.00-1.57) were independently associated with an increased risk of obesity at age 4.5 years. The cumulative PAF for childhood obesity was 42.9%, under an ideal scenario where all risk factors were eliminated. Conclusion: Exposure to modifiable factors by age 2 years is associated with obesity at age 4.5 years. Interventions to prevent childhood obesity need to be effective during infancy.

Pleiotropic genetic influence on birth weight and childhood obesity

Childhood obesity is a global public health problem. Understanding the molecular mechanisms that underlie early origins of childhood obesity can facilitate interventions. Consistent phenotypic and genetic correlations have been found between childhood obesity traits and birth weight (a proxy for in-utero growth), suggesting shared genetic influences (pleiotropy). We aimed to (1) investigate whether there is significant shared genetic influence between birth weight and childhood obesity traits, and (2) to identify genetic loci with shared effects. Using a statistical approach that integrates summary statistics and functional annotations for paired traits, we found strong evidence of pleiotropy (P < 3.53 × 10^–127) and enrichment of functional annotations (P < 1.62 × 10^–39) between birth weight and childhood body mass index (BMI)/obesity. The pleiotropic loci were enriched for regulatory features in skeletal muscle, adipose and brain tissues and in cell lines derived from blood lymphocytes. At 5% false discovery rate, 6 loci were associated with birth weight and childhood BMI and 13 loci were associated with birth weight and childhood obesity. Out of these 19 loci, one locus (EBF1) was novel to childhood obesity and one locus (LMBR1L) was novel to both birth weight and childhood BMI/obesity. These findings give evidence of substantial shared genetic effects in the regulation of both fetal growth and childhood obesity.

The FTO genetic variants are associated with dietary intake and body mass index amongst Emirati population

BACKGROUND

The risk of obesity is determined by complex interactions between genetic and environmental factors. Little research to date has investigated the interaction between gene and food intake. The aim of the current study is to explore the potential effect of fat mass and obesity-associated protein gene (FTO) rs9939609 and rs9930506 single nucleotide polymorphism (SNP) on the pattern of food intake in the Emirati population.

METHODS

Adult healthy Emirati subjects with Body mass index (BMI) of 16-40 kg/m2 were included in the study. Genotyping for FTO rs9939609(A>T) and rs9930506(A>G) was performed using DNA from saliva samples. Subjects were categorized according to the WHO classification by calculating the BMI to compare different classes. Dietary intake was assessed by a sixty-one-item FFQ that estimated food and beverage intakes over the past year. The daily energy, macronutrient, and micronutrient consumption were computed.

RESULTS

We included 169 subjects in the final analysis (mean age 30.49± 9.1years, 57.4% females). The mean BMI of the study population was 26.19 kg/m2. Both SNPs were in Hardy Weinberg Equilibrium. The rs9939609 AA genotype was significantly associated with higher BMI (p = 0.004); the effect was significant in females (p = 0.028), but not in males (p = 0.184). Carbohydrate intake was significantly higher in AA subjects with a trend of lower fat intake compared to other genotypes. The odds ratio for the AA was 3.78 in the fourth quartile and 2.67 for the A/T in the second quartile of total carbohydrate intake, considering the first quartile as a reference (95% CI = 1.017-14.1 and 1.03-6.88, respectively). Fat intake was significantly lower in the FTO rs9930506 GG subjects. The presence of FTO rs9930506 GG genotype decreased the fat intake in subjects with FTO rs9939609 AA (p = 0.037).

CONCLUSIONS

The results of this study highlight the interaction of the FTO risk alleles on the food intake in Emirati subjects. The FTO rs9939609 AA subjects had higher carbohydrate and lower fat intake. The latter was accentuated in presence of rs9930506 GG genotype.

Association between grandparent coresidence and weight change among first-grade Japanese children

BACKGROUND

The prevalence of grandparent coresidence is increasing. However, the impact of grandparent coresidence on weight change among school-age children remains unclear.

OBJECTIVES

The objective of the study is to examine the association between grandparent coresidence and obesity-related behaviours and change in body mass index (BMI) z scores among school-age children.

METHODS

In total, 3422 caregivers of first-grade children in Adachi City, Tokyo, participated in surveys and health checkups in 2016 and 2017 with no change in their grandparent coresidence status (response rate: 80.1% and 81.4%, respectively). Association between grandparent coresidence and obesogenic dietary, physical activity, and screen-based sedentary behaviours was measured using Poisson regression with robust error variance analysis, while change in BMI z scores was determined by linear regression and adjusting for potential covariates.

RESULTS

Grandparent coresidence was associated with increased prevalence rate (PR) of irregular snack foods intake (PR: 1.38, 95% confidential interval (CI): 1.19, 1.61); however, children who live with grandparents showed a lower BMI z scores in the second grade (coefficient: -0.048, 95% CI: -0.094 to -0.0013) after adjustment for BMI z scores in the first grade, family sociodemographics, and obesogenic behaviours.

CONCLUSION

Grandparent coresidence is associated with lower BMI z scores among early primary school-age Japanese children living in urban areas.

Association between fetal macrosomia and risk of obesity in children under 3 years in Western China: a cohort study

BACKGROUND

Fetal macrosomia, defined as birth weight equal or over 4000 g, is a major concern for both neonatal and maternal health. A rapid increasing trend in fetal macrosomia is observed in different regions of China. We aimed to examine the association between fetal macrosomia and risk of childhood obesity in Western China.

METHODS

All macrosomic live singletons (≥ 4000 g), and a random sample of singletons with normal birth weight (2500-3999 g) born in four districts of Chengdu, Western China, in 2011 were included in the cohort study. Maternal demographics, obstetric factors, labor and delivery summary at baseline were extracted from the Chengdu Maternal and Child Health Management System. Anthropometric measurements before 3 years and infant feeding information at around 6 months were also collected. Childhood obesity under 3 years was primarily defined as a weight-for-length/height z score ≥ 1.645 using the WHO growth reference. Secondary definitions were based on weight-for-age and body mass index (BMI)-for-age over the same cut-offs.

RESULTS

A total of 1767 infants were included in the analyses, of whom 714 were macrosomic. After controlling for maternal age, parity, gestational age and anemia at the first antenatal visit, pre-pregnancy BMI, gestational weight gain, gestational age at birth, baby age and sex, and breastfeeding practices at 6 months, the risk of childhood obesity defined according to weight-for-length/height among macrosomic babies was 1.90 (95% confidence interval 1.04-3.49) times that of babies with normal birth weight. The risk of childhood obesity for macrosomic babies was 3.74 (1.96-7.14) and 1.64 (0.89-3.00) times higher based on weight-for-age and BMI-for-age, respectively.

CONCLUSION

Fetal macrosomia is associated with increased risk of obesity in children under 3 years in Western China.

Elevated metabolites of acetaminophen in cord blood of children with obesity

BACKGROUND

High-throughput metabolomics has been used cross-sectionally to evaluate differential metabolic profiles associated with human obesity.

OBJECTIVES

This study longitudinally assessed the cord blood metabolome to explore if metabolic signatures of obesity at age 3-5 are apparent at birth.

METHODS

In a nested case-control design, metabolomics analysis was performed on umbilical cord blood of 25 children who developed obesity by age 3-5 years, compared with 25 sex-matched non-obese children enrolled as part of an ongoing birth cohort. Logistic regression models were used to identify significant metabolites, adjusting for maternal pre-pregnancy obesity.

RESULTS

Children who had obesity by age 3-5 years had elevated levels of medium and long chain fatty acids including stearate, oleate and palmitate at birth. Children with obesity were also more likely to have elevated levels of acetaminophen metabolites at birth, specifically: 3-(N-acetyl-L-cystein-S-yl) acetaminophen, 2-hydroxyacetaminophen sulfate, 2-methoxyacetaminophen glucuronide and p-acetamidophenyl glucuronide.

CONCLUSION

Although the observed increases in lipids are consistent with previous metabolomic studies of obesity, this study is the first to report associations between acetaminophen metabolites and obesity in children; however, we lack mechanistic insights for this link. Larger human studies with longer follow-up and laboratory-controlled animal experiments are needed to clarify associations.

Evaluating the risk factors that link obesity and dental caries in 11-17-year-old school going children in the United Arab Emirates

OBJECTIVE

The objective is to study the effect of obesity on dental caries among schoolchildren in Sharjah, United Arab Emirates.

MATERIALS AND METHODS

The sample comprised 803, 11-17-year-old schoolchildren. The study was in the form of a randomized cross-sectional manner. Method used was two questioners. The first assessed socioeconomic and general health and the second detailed their demographic, oral hygiene, and dietary habits. Dental examination included dental caries assessment using the World Health Organization 1997 criteria and gingival health valuation. Clinical examination consisted of height, weight, and body mass index (BMI). Data analysis was done by descriptive, univariate, and multiple regressions.

RESULTS

In this sample, 75% had dental caries and the mean decayed, missing, and filled teeth (DMFT) was 3.19 (standard deviation: 2.9). Obesity was seen in 15% of the adolescents and the mean BMI was 21. The link between DMFT and BMI, when evaluated using univariate analysis, showed a significant correlation (r = 0.097, P = 0.006), indicating that the rise in BMI by 10 points resulted in an increase in DMFT by 0.57. However, in the multivariate analysis, a significant relationship was observed only between father's education (P < 0.001), adolescent's age (P < 0.001), gender (P = 0.008), ethnicity (P = 0.001), and soft drink consumption with DMFT while BMI showed a significant association with age (P < 0.001), school fees (P = 0.005), obesity in family (P < 0.001), and soft drink consumption (P < 0.001).

CONCLUSIONS

Obesity and dental caries were not significantly associated. The most important predictor for obesity and dental caries was soft drink consumption.

Gene-nutrient interactions and susceptibility to human obesity

A large number of genome-wide association studies, transferability studies, and candidate gene studies performed in diverse populations around the world have identified gene variants that are associated with common human obesity. The mounting evidence suggests that these obesity gene variants interact with multiple environmental factors and increase susceptibility to this complex metabolic disease. The objective of this review article is to provide concise and updated information on energy balance, heritability of body weight, origins of gene variants, and gene-nutrient interactions in relation to human obesity. It is proposed that knowledge of these related topics will provide valuable insight for future preventative lifestyle intervention using targeted nutritional and medicinal therapies.

Physical Fitness, Physical Activity, Sedentary Behavior, or Diet-What Are the Correlates of Obesity in Polish School Children?

There is substantial evidence of rising prevalence of overweight and obesity and its co-morbidities among children in western-high income developed countries. In the European Union, the prevalence of overweight and obesity is increasing fastest among Polish children. Yet, there is paucity of evidence on the relationship of behavioral factors with body weight status of children in Poland. This study examined the association of obesity with physical fitness, physical activity, sedentary behavior and diet among Polish children. A total of 641 children (10-15 years) recruited from the Lower Silesia region of Poland participated in this cross-sectional study. Participants' anthropometrics, physical fitness, physical activity, sedentary behavior and dietary intake were assessed. Outcome variables were weight categories (according to body mass index [BMI], waist-to-hip ratio [WHR], and percentage body fat [% BF]). The strongest negative correlation was found between VO₂max and %BF (r = -0.39, p <0.05). Significant negative correlation was also found between VO₂max and weight categories (r = -0.15). Results of the multinomial logit analysis showed that VO₂max increased in groups of overweight, normal weight and underweight children by 13%, 26% and 19%, respectively as compared to the group of obese children. VO₂max and weight and obesity indices were strongly correlated in both gender and age groups. Education and intervention programs to increase physical fitness (VO₂max) through aerobic training are recommended for Physical Education teachers, parents and children in order to reduce the rate of overweight and obesity among children in the Lower Silesia region of Poland.

A Systematic Examination of the Association between Parental and Child Obesity across Countries

Childhood obesity has become a global epidemic. Parents can have an important influence on their children's health behaviors and weight status. Many studies have examined the association between parental and childhood weight status. However, much heterogeneity between studies exists, and the parent-child (P-C) association in obesity has varied. The purpose of this systematic examination and meta-analysis was to examine the strength and variation of the P-C association in obesity and to identify factors (e.g., demographic characteristics and country's economic level) that may influence this association. PubMed was searched for relevant studies published between January 2000 and July 2015. Thirty-two studies from 21 countries met inclusion criteria; 27 reported ORs for the P-C obesity association and were included in a meta-analysis. The meta-analysis showed a strong P-C obesity association (pooled OR: 2.22; 95% CI: 2.09, 2.36), which varied by type of P-C pair (i.e., parents-child, father-child, and mother-child), child age, parent and child weight status, and the country's economic level. Stronger associations were shown in older children than in younger children (β ± SE: 0.02 ± 0.01), in both parents than in father only (β ± SE: 0.51 ± 0.11) or mother only (β ± SE: 0.38 ± 0.11), in parental obesity (β ± SE: 0.26 ± 0.10) and child obesity (β ± SE: 0.28 ± 0.12) than in parental and child overweight, and in high- than in middle-income countries (β ± SE: 0.23 ± 0.08). Thus, research from multiple countries shows significant P-C associations in weight status, but this association varies by child age, type of P-C pair, weight status, and the country's economic level. Results suggest that families and parents should be a key target for obesity intervention efforts.

An integrative study identifies KCNC2 as a novel predisposing factor for childhood obesity and the risk of diabetes in the Korean population

Obesity is a major risk factor for type 2 diabetes. To unravel the genetic determinants of obesity-associated diabetes, we performed a genome-wide study using the 1,000 Genomes-based imputation in a Korean childhood cohort (KoCAS-1, n = 484) and carried out de novo replication in an independent population (KoCAS-2, n = 1,548). A novel variant (rs10879834) with multiple diverse associations for obesity-related traits was also found to be replicated in an adult cohort (KARE, n = 8,842). Functional annotations using integrative epigenetic analyses identified biological significance and regulatory effects with an inverse methylation-expression correlation (cg27154343 in the 5′-UTR of the KCNC2 gene), tissue-specific enhancer mark (H3K4me1), and pathway enrichment (insulin signaling). Further functional studies in cellular and mouse models demonstrated that KCNC2 is associated with anti-obesogenic effects in the regulation of obesity-induced insulin resistance. KCNC2 shRNA transfection induced endoplasmic reticulum (ER) stress and hepatic gluconeogenesis. Overproduction of KCNC2 decreased ER stress, and treatment with metformin enhanced KCNC2 expression. Taken together, these data suggest that reduction of KCNC2 is associated with modified hepatic gluconeogenesis and increased ER stress on obesity-mediated diabetic risk. An integrative multi-omics analysis might reveal new functional and clinical implications related to the control of energy and metabolic homeostasis in humans.

Depot- and sex-specific effects of maternal obesity in offspring's adipose tissue

According to the Developmental Origin of Health and Disease (DOHaD) concept, alterations of nutrient supply in the fetus or neonate result in long-term programming of individual body weight (BW) setpoint. In particular, maternal obesity, excessive nutrition, and accelerated growth in neonates have been shown to sensitize offspring to obesity. The white adipose tissue may represent a prime target of metabolic programming induced by maternal obesity. In order to unravel the underlying mechanisms, we have developed a rat model of maternal obesity using a high-fat (HF) diet (containing 60% lipids) before and during gestation and lactation. At birth, newborns from obese dams (called HF) were normotrophs. However, HF neonates exhibited a rapid weight gain during lactation, a key period of adipose tissue development in rodents. In males, increased BW at weaning (+30%) persists until 3months of age. Nine-month-old HF male offspring was normoglycemic but showed mild glucose intolerance, hyperinsulinemia, and hypercorticosteronemia. Despite no difference in BW and energy intake, HF adult male offspring was predisposed to fat accumulation showing increased visceral (gonadal and perirenal) depots weights and hyperleptinemia. However, only perirenal adipose tissue depot exhibited marked adipocyte hypertrophy and hyperplasia with elevated lipogenic (i.e. sterol-regulated element binding protein 1 (Srebp1), fatty acid synthase (Fas), and leptin) and diminished adipogenic (i.e. peroxisome proliferator-activated receptor gamma (Pparγ), 11β-hydroxysteroid dehydrogenase type 1 (11β-Hds1)) mRNA levels. By contrast, very few metabolic variations were observed in HF female offspring. Thus, maternal obesity and accelerated growth during lactation program offspring for higher adiposity via transcriptional alterations of visceral adipose tissue in a depot- and sex-specific manner.

The association between maternal nutrition and lifestyle during pregnancy and 2-year-old offspring adiposity: analysis from the ROLO study

Aim

To examine the association between maternal nutrition and lifestyle factors and offspring adiposity, using baseline and 2-year postpartum follow-up data from a randomised control trial of low glycaemic index diet.

Subject and methods

Food diaries and lifestyle questionnaires were completed during pregnancy and infant feeding and maternal lifestyle questionnaires 2 years postpartum for 281 mother and infant pairs from the ROLO study. Maternal anthropometry was measured throughout pregnancy and infant and maternal anthropometry was measured 2 years postpartum.

Results

Maternal 2 year postpartum body mass index (BMI) was positively associated with offspring BMI-for-age z-score (B = 0.105, p = 0.015). Trimester 2 saturated fat intake was positively associated with offspring subscapular:triceps skinfold ratio (B = 0.018, p = 0.001). Trimester 1 glycaemic index was also positively associated with offspring sum of subscapular and triceps skinfolds (B = 0.009, p = 0.029).

Conclusions

Maternal BMI 2 years postpartum was positively associated with offspring BMI. Pregnancy saturated fat intake was positively and polyunsaturated fat negatively associated with offspring adiposity. While further research is necessary, pregnancy and the postpartum period may be early opportunities to combat childhood obesity.

Electronic supplementary material

The online version of this article (doi:10.1007/s10389-016-0740-9) contains supplementary material, which is available to authorized users.

Relation of FTO gene variants to fetal growth trajectories: Findings from the Southampton Women's survey

Introduction

Placental function is an important determinant of fetal growth, and fetal growth influences obesity risk in childhood and adult life. Here we investigated how FTO and MC4R gene variants linked with obesity relate to patterns of fetal growth and to placental FTO expression.

Methods

Southampton Women's Survey children (n = 1990) with measurements of fetal growth from 11 to 34 weeks gestation were genotyped for common gene variants in FTO (rs9939609, rs1421085) and MC4R (rs17782313). Linear mixed-effect models were used to analyse relations of gene variants with fetal growth.

Results

Fetuses with the rs9939609 A:A FTO genotype had faster biparietal diameter and head circumference growth velocities between 11 and 34 weeks gestation (by 0.012 (95% CI 0.005 to 0.019) and 0.008 (0.002–0.015) standard deviations per week, respectively) compared to fetuses with the T:T FTO genotype; abdominal circumference growth velocity did not differ between genotypes. FTO genotype was not associated with placental FTO expression, but higher placental FTO expression was independently associated with larger fetal size and higher placental ASCT2, EAAT2 and y + LAT2 amino acid transporter expression. Findings were similar for FTO rs1421085, and the MC4R gene variant was associated with the fetal growth velocity of head circumference.

Discussion

FTO gene variants are known to associate with obesity but this is the first time that the risk alleles and placental FTO expression have been linked with fetal growth trajectories. The lack of an association between FTO genotype and placental FTO expression adds to emerging evidence of complex biology underlying the association between FTO genotype and obesity.

•

Variants in the FTO gene are previously known to be associated with obesity.

•

discovered novel associations between FTO variants and growth trajectory of fetal head measures.

•

also found novel associations between placental FTO expression and fetal size.

Stable intergenerational associations of childhood overweight during the development of the obesity epidemic

OBJECTIVE

The obesity epidemic may have developed as a response to the obesogenic environment among the genetically predisposed. This investigation examined whether the intergenerational resemblances in childhood overweight changed across the development of the obesity epidemic in groups of children born to parents with and without childhood overweight.

METHODS

The study population was from the Copenhagen School Health Records Register, which includes age- and sex-specific body mass index (BMI; kg/m(2) ) of children. This study used BMI values from 7-year-old children born 1952-1989 and from their parents at ages 7 and 13 years. The available number of parent-child pairs ranged from 17,926 through 42,184. The odds ratios of childhood overweight (BMI z-score >90th percentile) were calculated using logistic regression by parental BMI groups (BMI > or ≤90th percentile) and child birth year intervals.

RESULTS

Stable levels in parent-child overweight associations were observed across child BMI groups born to parents with and without childhood overweight. A slight upward odds ratio trend was observed across time in children born to two overweight parents at age 13, but not at age 7 years.

CONCLUSIONS

Parent-child resemblance in childhood overweight showed small changes during the development of the obesity epidemic, suggesting that the obesogenic environment inducing the epidemic in Denmark influenced children irrespective of their familial predisposition.

Influence of early life factors on body mass index trajectory during childhood: a population-based longitudinal analysis in the Western Brazilian Amazon

Low- to middle-income countries may experience the occurrence of a dual burden of under and overnutrition. To better understand the overall progression of body mass index (BMI) during childhood, we estimated average BMI-for-age z-score (BAZ) growth curves in a population-based longitudinal study of 255 children living in the Brazilian Amazon. Children were aged 0.1-5.5 years at recruitment (2003). We collected data on socio-economic and maternal characteristics, children's birthweight and infant feeding practices. Child anthropometric measurements were taken in 2003, 2007 and 2009. BAZ differences among categories of exposure variables were calculated at 6 and 12 months, and 2, 7 and 10 years. At baseline, the mean (standard deviation) age was 2.6 (1.4) years; 12.9% were overweight and 3.9% thin. After adjustment, mean BAZ estimates were mostly negative. Boys were close to the median value for BAZ until 12 months, whereas girls were below the median (P=0.05). Children from households above the wealth median were 0.36 z- and 0.49 z-less underweight than poorer children at 7 and 10 years, respectively (P<0.01). Maternal BMI was positively associated with children's BAZ since 12 months old; BAZ in children from overweight mothers was higher by 0.69 compared with their counterparts at 10 years (P<0.01). Birthweight was positively related to BAZ up until 2 years (P=0.01). Socio-economic background and maternal nutritional status are important predictors of BAZ throughout childhood. Although excessive weight gain is a public health concern, it is critical to restrict inequities, while promoting healthier growth in developing countries.

Knowledge and attitudes towards obesity among primary school children in Dar es Salaam, Tanzania

BACKGROUND

Childhood obesity has increased over the past two decades. Child obesity is likely to persist through adulthood and increases the risk of non-communicable diseases (NCDs) later in life. This study assessed knowledge and attitudes towards obesity among primary school children in Dar es Salaam, Tanzania.

MATERIALS AND METHODS

A cross-sectional study was conducted in randomly selected primary schools in Dar es Salaam. A structured questionnaire was used to assess the knowledge and attitudes. Anthropometric and blood pressure measurements were taken using standard procedures.

RESULTS

A total of 446 children were included in the analysis. The mean age of the participants was 11.1 ± 2.0 years. The mean body mass index (BMI), systolic blood pressure (SBP) and diastolic blood pressure (DBP) were 16.6 ± 4.0 kg/m(2), 103.9 ± 10.3 mmHg and 65.6 ± 8.2 mmHg, respectively. Prevalence of obesity (defined as BMI >95(th) percentile for age and sex) was 5.2%. Half of the children (51.1%) had heard about obesity from teachers at school (20%), radio (19.4%) and books/newspaper (17.3%). Less than half (45.4%) had knowledge about the risk factors for childhood obesity and correctly defined obesity (44.6%). However, a good number of the children (72.1%) were aware that they can be affected by obesity. Majority of them had negative attitude towards obesity and various factors leading to or resulting from childhood obesity.

CONCLUSIONS

Knowledge about childhood obesity among primary school children is moderate and have negative attitude towards obesity. Integrating educational programs early in primary schools may be an effective strategy to impact knowledge about obesity and other non-communicable diseases early in childhood.

Epigenetic effects of paternal diet on offspring: emphasis on obesity

Overnutrition, obesity, and the rise in associated comorbidities are widely recognized as preventable challenges to global health. Behavioral, metabolic, and epigenetic influences that alter the epigenome, when passed on to offspring, can increase their risk of developing an altered metabolic profile. This review is focused on the role of paternal inheritance as demonstrated by clinical, epidemiological, and experimental models. Development of additional experimental models that resemble the specific epigenetic sensitive situations in human studies will be essential to explore paternally induced trans-generational effects that are mediated, primarily, by epigenetic effects. Further elucidation of epigenetic marks will help identify preventive and therapeutic targets, which in combination with healthy lifestyle choices, can diminish the growing tide of obesity, type 2 diabetes, and other related disorders.

Enriched environment-induced maternal weight loss reprograms metabolic gene expression in mouse offspring

The global prevalence of weight loss is increasing, especially in young women. However, the extent and mechanisms by which maternal weight loss affects the offspring is still poorly understood. Here, using an enriched environment (EE)-induced weight loss model, we show that maternal weight loss improves general health and reprograms metabolic gene expression in mouse offspring, and the epigenetic alterations can be inherited for at least two generations. EE in mothers induced weight loss and its associated physiological and metabolic changes such as decreased adiposity and improved glucose tolerance and insulin sensitivity. Relative to controls, their offspring exhibited improved general health such as reduced fat accumulation, decreased plasma and hepatic lipid levels, and improved glucose tolerance and insulin sensitivity. Maternal weight loss altered gene expression patterns in the liver of offspring with coherent down-regulation of genes involved in lipid and cholesterol biosynthesis. Epigenomic profiling of offspring livers revealed numerous changes in cytosine methylation depending on maternal weight loss, including reproducible changes in promoter methylation over several key lipid biosynthesis genes, correlated with their expression patterns. Embryo transfer studies indicated that oocyte alteration in response to maternal metabolic conditions is a strong factor in determining metabolic and epigenetic changes in offspring. Several important lipid metabolism-related genes have been identified to partially inherit methylated alleles from oocytes. Our study reveals a molecular and mechanistic basis of how maternal lifestyle modification affects metabolic changes in the offspring.

Heritability of aerobic power of individuals in northeast Brazil

The objective of this study was to evaluate the genetic and environmental contribution to variation in aerobic power in monozygotic (MZ) and dizygotic (DZ) twins. The sample consisted of 20 MZ individuals (12 females and 8 males) and 16 DZ individuals (12 females and 4 males), aged from 8 to 26 years, residents in Natal, Rio Grande do Norte. The twins were assessed by a multistage fitness test. The rate of heritability found for aerobic power was 77%. Based on the results, the estimated heritability was largely responsible for the differences in aerobic power. This implies that such measures are under strong genetic influence.

Environmental epigenetic inheritance through gametes and implications for human reproduction

BACKGROUND

Traditional studies focused on DNA as the heritable information carrier that passes the phenotype from parents to offspring. However, increasing evidence suggests that information, that is independent of the DNA sequence, termed epigenetic information, can be inherited between generations. Recently, in our lab, we found that prediabetes in fathers increases the susceptibility to diabetes in offspring through gametic cytosine methylation changes. Paternal prediabetes changed overall methylation patterns in sperm, and a large portion of differentially methylated loci can be transmitted to pancreatic islets of offspring up to the second generation. In this review, we survey the extensive examples of environmentally induced epigenetic inheritance in various species, ranging from Caenorhabditis elegans to humans. We focus mainly on elucidating the molecular basis of environmental epigenetic inheritance through gametes, which is an emerging theme and has important implications for explaining the prevalence of obesity, type 2 diabetes and other chronic non-genetic diseases, which is also important for understanding the influence of environmental exposures on reproductive and overall health in offspring.

METHODS

For this review, we included relevant data and information obtained through a PubMed database search for all English language articles published up to August 2014 which included the term 'environmental epigenetic inheritance' and 'transgenerational epigenetic inheritance'. We focused on research papers using animal models including Drosophila, C. elegans, mouse and rat. Human data were also included.

RESULTS

Evidence from animal models suggests that environmental epigenetic inheritance through gametes exists in various species. Extensive molecular evidence suggests that epigenetic information carriers including DNA methylation, non-coding RNAs and chromatin proteins in gametes play important roles in the transmission of phenotypes from parents to offspring.

CONCLUSIONS

Given the large number of experimental evidence from various organisms, it is clear that parental environmental alterations can affect the phenotypes of offspring through gametic epigenetic alterations. This more recent thinking based on new data may have implications in explaining the prevalence of obesity, type 2 diabetes and other chronic non-genetic diseases. This also implies that, in the near future, epigenetic factors which are heritable should be regarded important in determining the risk of certain diseases. Moreover, identification of epigenetic markers in gametes (polar body or sperm) may hold great promise for predicting susceptibility to and preventing certain non-genetic diseases in offspring, as well as providing indications on parental environmental exposures.

Correlates of adiposity in a Caribbean pre-school population

OBJECTIVE

To evaluate ethnic and anthropometric correlates of adiposity among a nationally representative, multi-ethnic, Trinidadian pre-school population.

DESIGN

Cross-sectional study conducted between June 2008 and July 2009.

SETTING

Government and privately owned Early Childhood Care and Education Centres in Trinidad.

SUBJECTS

A total of 596 pre-school children (aged 31-73 months) from thirty-four schools had their weight, height, mid-upper arm circumference, waist circumference, biceps and triceps skinfold thicknesses measured by a registered dietitian using standard procedures. Percentage body fat was estimated using a foot-to-foot bioelectric impedance analyser (Tanita 531, Tokyo, Japan). Date of birth, religion and ethnicity were extracted from school records and pre-schoolers' ethnicity was categorized as East Indian, African, Mixed (a combination of two or more ethnicities), Chinese or Caucasian.

RESULTS

Anthropometric variables explained significantly more of the variance in adiposity among girls (67·4-88·1 %) than boys (24·4-39·2 %; P < 0·0 0 1). Pre-schoolers of African descent were significantly taller, heavier and had higher abdominal fat and mid-upper arm circumference than their East Indian and Mixed counterparts (all P < 0·001). The overall prevalence of excess adiposity (≥25 % body fat) as determined by bioelectrical impedance was 14·6 %, while 2·9 % of the children were undernourished according to WHO weight-for-age criteria. Differences in anthropometry were non-existent between children attending government and private pre-schools.

CONCLUSIONS

Gender, ethnicity and anthropometry all explained excess adiposity in these pre-schoolers. These findings highlight the need to elucidate the mechanisms that may be involved in explaining these differences, particularly those of ethnic origin.

Physical activity in American schools and body mass index percentile

The international physical inactivity epidemic among children has contributed to child obesity. Schools can be an effective source of physical activity opportunity. A cross-sectional sample of 1306 American children was drawn from the Panel Study of Income Dynamics - Child Development Supplement, 2007. The aim of this study was to determine the role of in-school physical activity on body mass index (BMI) percentile among middle and high school-aged children. Multinomial logistic regression was used to assess the associations between the independent variable, physical activity, and the dependent variable, BMI percentile. After adjusting for covariates, children who had no physical activity during physical education (PE) were much more likely to be obese than normal weight in comparison with those who met the US national requirements (odds ratio = 1.58, confidence interval = 1.14, 2.20). This study suggests that meeting US national guidelines for PE-related physical activity may be effective in preventing obesity.

Maternal obesity - a risk factor for metabolic syndrome in children

OBJECTIVE

To determine the association between the metabolic syndrome in children (MS) and the pre-pregnancy nutritional status of the mother.

DESIGN AND METHODS

A total number of 180 children aged between 6-19 years were examined. Self reported data about parents and their children were collected. The children underwent physical examination; weight, height, waist circumference, blood pressure (BP) were measured. The nutritional status of the children was assessed by body mass index (BMI) and laboratory tests needed to diagnose MS were performed. IDF criteria for MS were used in children 10 years and older, and age and gender specific cut-off points in children younger than 10 years. The mothers were classified in the normal weight, overweight and obese categories according to the pre-pregnancy BMI. The statistical analysis of the data was descriptive and inferential analysis. In the bivariate analysis of the association between qualitative variables, we used the Chi-Square test and the exact Fisher test. The statistical analysis was performed with SPSS v 13.0.

RESULTS

73 (40.55%) children were normal weight, 54 (30%) were overweight and 53 (29.44%) were obese. None of the normal weight children, 16 (29.60%) of the overweight and 23 (43.40%) of the obese ones had MS; 125 (69.44%) of the mothers were normal weight, 44 (24.44%) were overweight and 11 (6.11%) were obese. Pre-pregnancy maternal BMI was significantly associated with offspring MS in both genders, obese children and in the 10-16 age group.

CONCLUSIONS

Pre-pregnancy maternal overweight/obesity represents a risk factor for offspring MS. The results are very difficult to compare between studies because of different cut-off values and definition of MS in children. If prevention is the goal rather than treatment, the perinatal period may be an important focus for future research.

Associations of PON1 and genetic ancestry with obesity in early childhood

Obesity in children has become an epidemic in the U.S. and is particularly prominent in minority populations such as Mexican-Americans. In addition to physical activity and diet, genetics also plays a role in obesity etiology. A few studies in adults and adolescents suggest a link between obesity and paraoxonase 1 (PON1), a multifunctional enzyme that can metabolize organophosphate pesticides and also has antioxidant properties. We determined PON1₁₉₂ genotype and arylesterase levels (ARYase, measure of PON1 enzyme quantity), to characterize the relationship between PON1 and obesity in young Mexican-American children (n = 373) living in an agricultural community in California. Since PON1 polymorphisms and obesity both vary between ethnic groups, we estimated proportional genetic ancestry using 106 ancestral informative markers (AIMs). Among children, PON1₁₉₂ allele frequencies were 0.5 for both alleles, and the prevalence of obesity was high (15% and 33% at ages two and five, respectively). The average proportion of European, African, and Native American ancestry was 0.40, 0.09, and 0.51, yet there was wide inter-individual variation. We found a significantly higher odds of obesity (9.3 and 2.5- fold) in PON1_192QQ children compared to PON1_192RR children at ages two and five, respectively. Similar relationships were seen with BMI Z-scores at age two and waist circumference at age five. After adjusting for genetic ancestry in models of PON1 and BMI Z-score, effect estimates for PON1₁₉₂ genotype changed 15% and 9% among two and five year old children, respectively, providing evidence of genetic confounding by population stratification. However even after adjustment for genetic ancestry, the trend of increased BMI Z-scores with increased number of PON1₁₉₂ Q alleles remained. Our findings suggest that PON1 may play a role in obesity independent of genetic ancestry and that studies of PON1 and health outcomes, especially in admixed populations, should account for differences due to population stratification.

The genetics of childhood obesity and interaction with dietary macronutrients

The genes contributing to childhood obesity are categorized into three different types based on distinct genetic and phenotypic characteristics. These types of childhood obesity are represented by rare monogenic forms of syndromic or non-syndromic childhood obesity, and common polygenic childhood obesity. In some cases, genetic susceptibility to these forms of childhood obesity may result from different variations of the same gene. Although the prevalence for rare monogenic forms of childhood obesity has not increased in recent times, the prevalence of common childhood obesity has increased in the United States and developing countries throughout the world during the past few decades. A number of recent genome-wide association studies and mouse model studies have established the identification of susceptibility genes contributing to common childhood obesity. Accumulating evidence suggests that this type of childhood obesity represents a complex metabolic disease resulting from an interaction with environmental factors, including dietary macronutrients. The objective of this article is to provide a review on the origins, mechanisms, and health consequences of obesity susceptibility genes and interaction with dietary macronutrients that predispose to childhood obesity. It is proposed that increased knowledge of these obesity susceptibility genes and interaction with dietary macronutrients will provide valuable insight for individual, family, and community preventative lifestyle intervention, and eventually targeted nutritional and medicinal therapies.

Ethnicity, educational level and attitudes contribute to parental intentions about genetic testing for child obesity

The objective of this paper is to assess parental beliefs and intentions about genetic testing for their children in a multi-ethnic population with the aim of acquiring information to guide interventions for obesity prevention and management. A cross-sectional survey was conducted in parents of native Dutch children and children from a large minority population (Turks) selected from Youth Health Care registries. The age range of the children was 5-11 years. Parents with lower levels of education and parents of non-native children were more convinced that overweight has a genetic cause and their intentions to test the genetic predisposition of their child to overweight were firmer. A firmer intention to test the child was associated with the parents' perceptions of their child's susceptibility to being overweight, a positive attitude towards genetic testing, and anticipated regret at not having the child tested while at risk for overweight. Interaction effects were found in ethnic and socio-economic groups. Ethnicity and educational level play a role in parental beliefs about child overweight and genetic testing. Education programmes about obesity risk, genetic testing and the importance of behaviour change should be tailored to the cultural and behavioural factors relevant to ethnic and socio-economic target groups.