Salivary epigenetic biomarkers as predictors of emerging childhood obesity.
ABSTRACT: BACKGROUND:Epigenetics could facilitate greater understanding of disparities in the emergence of childhood obesity. While blood is a common tissue used in human epigenetic studies, saliva is a promising tissue. Our prior findings in non-obese preschool-aged Hispanic children identified 17 CpG dinucleotides for which differential methylation in saliva at baseline was associated with maternal obesity status. The current study investigated to what extent baseline DNA methylation in salivary samples in these 3-5-year-old Hispanic children predicted the incidence of childhood obesity in a 3-year prospective cohort. METHODS:We examined a subsample (n =?92) of Growing Right Onto Wellness (GROW) trial participants who were randomly selected at baseline, prior to randomization, based on maternal phenotype (obese or non-obese). Baseline saliva samples were collected using the Oragene DNA saliva kit. Objective data were collected on child height and weight at baseline and 36?months later. Methylation arrays were processed using standard protocol. Associations between child obesity at 36?months and baseline salivary methylation at the previously identified 17 CpG dinucleotides were evaluated using multivariable logistic regression models. RESULTS:Among the n =?75 children eligible for analysis, baseline methylation of Cg1307483 (NRF1) was significantly associated with emerging childhood obesity at 36-month follow-up (OR?=?2.98, p =?0.04), after adjusting for child age, gender, child baseline BMI-Z, and adult baseline BMI. This translates to a model-estimated 48% chance of child obesity at 36-month follow-up for a child at the 75th percentile of NRF1 baseline methylation versus only a 30% chance of obesity for a similar child at the 25th percentile. Consistent with other studies, a higher baseline child BMI-Z during the preschool period was associated with the emergence of obesity 3?years later, but baseline methylation of NRF1 was associated with later obesity even after adjusting for child baseline BMI-Z. CONCLUSIONS:Saliva offers a non-invasive means of DNA collection and epigenetic analysis. Our proof of principle study provides sound empirical evidence supporting DNA methylation in salivary tissue as a potential predictor of subsequent childhood obesity for Hispanic children. NFR1 could be a target for further exploration of obesity in this population.
Project description:BACKGROUND:The study of epigenetic processes and mechanisms present a dynamic approach to assess complex individual variation in obesity susceptibility. However, few studies have examined epigenetic patterns in preschool-age children at-risk for obesity despite the relevance of this developmental stage to trajectories of weight gain. We hypothesized that salivary DNA methylation patterns of key obesogenic genes in Hispanic children would 1) correlate with maternal BMI and 2) allow for identification of pathways associated with children at-risk for obesity. RESULTS:Genome-wide DNA methylation was conducted on 92 saliva samples collected from Hispanic preschool children using the Infinium Illumina HumanMethylation 450 K BeadChip (Illumina, San Diego, CA, USA), which interrogates >484,000 CpG sites associated with ~24,000 genes. The analysis was limited to 936 genes that have been associated with obesity in a prior GWAS Study. Child DNA methylation at 17 CpG sites was found to be significantly associated with maternal BMI, with increased methylation at 12 CpG sites and decreased methylation at 5 CpG sites. Pathway analysis revealed methylation at these sites related to homocysteine and methionine degradation as well as cysteine biosynthesis and circadian rhythm. Furthermore, eight of the 17 CpG sites reside in genes (FSTL1, SORCS2, NRF1, DLC1, PPARGC1B, CHN2, NXPH1) that have prior known associations with obesity, diabetes, and the insulin pathway. CONCLUSIONS:Our study confirms that saliva is a practical human tissue to obtain in community settings and in pediatric populations. These salivary findings indicate potential epigenetic differences in Hispanic preschool children at risk for pediatric obesity. Identifying early biomarkers and understanding pathways that are epigenetically regulated during this critical stage of child development may present an opportunity for prevention or early intervention for addressing childhood obesity. TRIAL REGISTRATION:The clinical trial protocol is available at ClinicalTrials.gov ( NCT01316653 ). Registered 3 March 2011.
Project description:OBJECTIVE:To determine the magnitude of risk of factors that contribute to the emergence of childhood obesity among low-income minority children. STUDY DESIGN:We conducted a prospective cohort analysis of parent-child pairs with children aged 3-5 years who were nonobese (n = 605 pairs) who participated in a 3-year randomized controlled trial of a healthy lifestyle behavioral intervention. After baseline, height and weight were measured 5 times over 3 years to calculate body mass index (BMI) percentiles and classify children as normal, overweight, or obese. Multivariable logistic regression was used to estimate the odds of obesity after 36 months. Predictors included age, sex, birth weight, gestational age, months of breastfeeding, ethnicity, baseline child BMI, energy intake, physical activity, food security, parent baseline BMI, and parental depression. RESULTS:Among this predominantly low-income minority population, 66% (398/605) of children were normal weight at baseline and 34% (n = 207/605) were overweight. Among normal weight children at baseline, 24% (85/359) were obese after 36 months; among overweight children at baseline, 55% (n = 103/186) were obese after 36 months. Age at enrollment (OR 2.11, 95% CI 1.64-2.72), child baseline BMI (OR 3.37, 95% CI 2.51-4.54), and parent baseline BMI (OR for a 6-unit change 1.36, 95% CI 1.09-1.70) were significantly associated with the odds of becoming obese for children. CONCLUSIONS:The combination of child age, parent BMI, and child overweight as predictors of child obesity suggest a paradigm of family-centered obesity prevention beginning in early childhood, emphasizing the relevance of child overweight as a phenotype highly predictive of child obesity. TRIAL REGISTRATION:Clinicaltrials.gov: NCT01316653.
Project description:Epigenetics presents a dynamic approach to assess complex individual variation in obesity susceptibility. However, few studies have examined epigenetic patterns in preschool-age children, despite the relevance of this developmental stage to trajectories of weight gain, because of difficulties obtaining blood tissue samples. This proof of principle study examined DNA methylation in 92 saliva samples, comparing Latino preschool children of normal weight mothers (Body Mass Index [BMI] <27 kg/m2 and WC <90 cm) to children of obese mothers (BMI >30 kg/m2 and WC >100 cm). We hypothesized that salivary DNA methylation patterns in Latino preschool age children born of normal weight vs obese weight mothers would be: 1) associated with maternal BMI phenotype in continuous linear regression analysis; 2) saliva could demonstrate epigenetic variation across individuals; and 3) preschool child saliva would be differentially methylated when comparing those children with obese versus normal weight mothers. One hundred and nineteen CpG sites were significantly (p-value <1.56 X 10-5, p-value adjusted <.05) associated with maternal BMI in linear regression models controlling for child’s age, gender, and BMI. Of these 119 CpG sites, 41 were found within the transcription start site, 5’ UTR, 3’ UTR, or another regulatory region outside of the gene body. Saliva, a practical human tissue to obtain in naturalistic settings and in pediatric populations, was confirmed to be a viable medium for genome-wide epigenetic testing with maternal weight. Although not identical to results yielded from other human tissue types (i.e., cord blood samples), saliva findings indicate potential epigenetic differences in Latino preschool children at risk for pediatric obesity. This proof of principle study examined DNA methylation in 92 saliva samples, comparing Latino preschool children of normal weight mothers (Body Mass Index [BMI] <27 kg/m2 and WC <90 cm) to children of obese mothers (BMI >30 kg/m2 and WC >100 cm). Antropometry was measured objectively according to a standardized protocol.Saliva from preschool Latino children at risk for obesity (BMI>50% < 95% participating in WIC/SNAP programs) was collected using the Oragene DNA saliva kit following a strict data collection protocol. DNA extraction was performed as per DNA Genotek's recommendations using the PrepIT L2P reagent. Extracted DNA was stored in individually barcoded cryovials at –80 degrees Fahrenheit. For children, saliva was obtained using the “baby brush” approach, in which small sponges attached to plastic handles are inserted between cheek and gumline to absorb saliva .Arrays were processed using standard protocol , with 3 samples randomly selected to serve as duplicates and 1 sample run with HapMap DNA to test functionality of reagents. Duplicates were measured for high technique consistency with Pearson correlation coefficient (>.99). Methylation data were quality controlled using Illumina GenomeStudio (V2011.1), Methylation module (V1.9.0). Samples with lower than 98% call rate (i.e. <485,000 probes) were excluded. Any non-specific cross-reacting probes, probes carrying common SNPs (MAF >1%), or any probes with p-values greater than 0.05 for more than 20% of the sample were sequentially excluded. Validation via pyrosequencing was conducted.
Project description:Importance:Prevention of obesity during childhood is critical for children in underserved populations, for whom obesity prevalence and risk of chronic disease are highest. Objective:To test the effect of a multicomponent behavioral intervention on child body mass index (BMI, calculated as weight in kilograms divided by height in meters squared) growth trajectories over 36 months among preschool-age children at risk for obesity. Design, Setting, and Participants:A randomized clinical trial assigned 610 parent-child pairs from underserved communities in Nashville, Tennessee, to a 36-month intervention targeting health behaviors or a school-readiness control. Eligible children were between ages 3 and 5 years and at risk for obesity but not yet obese. Enrollment occurred from August 2012 to May 2014; 36-month follow-up occurred from October 2015 to June 2017. Interventions:The intervention (n?=?304 pairs) was a 36-month family-based, community-centered program, consisting of 12 weekly skills-building sessions, followed by monthly coaching telephone calls for 9 months, and a 24-month sustainability phase providing cues to action. The control (n?=?306 pairs) consisted of 6 school-readiness sessions delivered over the 36-month study, conducted by the Nashville Public Library. Main Outcomes and Measures:The primary outcome was child BMI trajectory over 36 months. Seven prespecified secondary outcomes included parent-reported child dietary intake and community center use. The Benjamini-Hochberg procedure corrected for multiple comparisons. Results:Participants were predominantly Latino (91.4%). At baseline, the mean (SD) child age was 4.3 (0.9) years; 51.9% were female. Household income was below $25?000 for 56.7% of families. Retention was 90.2%. At 36 months, the mean (SD) child BMI was 17.8 (2.2) in the intervention group and 17.8 (2.1) in the control group. No significant difference existed in the primary outcome of BMI trajectory over 36 months (P?=?.39). The intervention group children had a lower mean caloric intake (1227 kcal/d) compared with control group children (1323 kcal/d) (adjusted difference, -99.4 kcal [95% CI, -160.7 to -38.0]; corrected P?=?.003). Intervention group parents used community centers with their children more than control group parents (56.8% in intervention; 44.4% in control) (risk ratio, 1.29 [95% CI, 1.08 to 1.53]; corrected P?=?.006). Conclusions and Relevance:A 36-month multicomponent behavioral intervention did not change BMI trajectory among underserved preschool-age children in Nashville, Tennessee, compared with a control program. Whether there would be effectiveness for other types of behavioral interventions or implementation in other cities would require further research. Trial Registration:ClinicalTrials.gov Identifier: NCT01316653.
Project description:To calculate the association of maternal salivary bacterial challenge (mutans streptococci [MS] and lactobacilli [LB]) from pregnancy through 24 months' postpartum with child caries incidence (?1 cavitated or restored teeth) at 36 months.Dental, salivary bacterial, sociodemographic, and behavioral measures were collected at three- to six-month intervals from a birth cohort of low-income Hispanic mother-child dyads (N = 243). We calculated the relative child caries incidence, adjusted for confounding, following higher maternal challenge of MS (>4500 colony-forming units per milliliter of saliva [CFU/mL]) and LB (>50 CFU/mL) based on multivariable models.Salivary MS and LB levels were greater among mothers of caries-affected children versus caries-free children. Mothers with higher salivary MS challenge were more likely to have MS-positive children (>0 CFU/mL), but maternal LB challenge was not a statistically significant predictor of child LB-positive status. Adjusting for sociodemographics, feeding and care practices, and maternal dental status, higher maternal salivary challenge of both MS and LB over the study period predicted nearly double the child caries incidence versus lower MS and LB (cumulative incidence ratio: 1.9; 95% confidence interval: 1.1, 3.8).Maternal salivary bacterial challenge not only is associated with oral infection among children but also predicts increased early childhood caries occurrence.
Project description:An imbalance between energy uptake and energy expenditure is the most important reason for increasing trends in obesity starting from early in life. Extracellular miRNAs are expressed in all bodily fluids and their expression is influenced by a broad range of stimuli. We examined whether screen time, physical activity and BMI are associated with children's salivary extracellular miR-222 and miR-146a expression. In 80 children the extracellular fraction of saliva was obtained by means of differential centrifugation and ultracentrifugation. Expression levels of miR-222 and miR-146a were profiled by qPCR. We studied the association between children's salivary extracellular miRNA expression and screen time, physical activity and BMI using mixed models, while accounting for potential confounders. We found that higher screen time was positively associated with salivary extracellular miR-222 and miR-146a levels. On average, one hour more screen time use per week was associated with a 3.44% higher miR-222 (95% CI: 1.34 to 5.58; p?=?0.002) and 1.84% higher miR-146a (95% CI: -0.04 to 3.75; p?=?0.055) level in saliva. BMI and physical activity of the child were not significantly associated with either miR-222 or miR-146a. A sedentary behaviour, represented by screen time use in children, is associated with discernible changes in salivary expression of miR-146a and or miR-222. These miRNA targets may emerge attractive candidates to explore the role of these exposures in developmental processes of children's health.
Project description:OBJECTIVES:To evaluate the impact of the GOALS (Getting Our Active Lifestyles Started) family-based childhood obesity treatment intervention during the first 3?years of implementation. DESIGN:Single-group repeated measures with qualitative questionnaires. SETTING:Community venues in a socioeconomically deprived, urban location in the North-West of England. PARTICIPANTS:70 overweight or obese children (mean age 10.5?years, 46% boys) and their parents/carers who completed GOALS between September 2006 and March 2009. INTERVENTIONS:GOALS was a childhood obesity treatment intervention that drew on social cognitive theory to promote whole family lifestyle change. Sessions covered physical activity (PA), diet and behaviour change over 18 2?h weekly group sessions (lasting approximately 6?months). A Template for Intervention Description and Replication (TIDieR) checklist of intervention components is provided. PRIMARY AND SECONDARY OUTCOME MEASURES:The primary outcome measure was child body mass index (BMI) z-score, collected at baseline, post-intervention and 12?months. Secondary outcome measures were child self-perceptions, parent/carer BMI and qualitative changes in family diet and PA (parent/carer questionnaire). RESULTS:Child BMI z-score reduced by 0.07 from baseline to post-intervention (p<0.001) and was maintained at 12?months (p<0.05). There was no change in parent/carer BMI or child self-perceptions, other than an increase in perceived social acceptance from baseline to post-intervention (p<0.05). Parents/carers reported positive changes to family PA and dietary behaviours after completing GOALS. CONCLUSIONS:GOALS completion was associated with small improvements in child BMI z-score and improved family PA and dietary behaviours. Several intervention modifications were necessary during the implementation period and it is suggested childhood obesity treatment interventions need time to embed before a definitive evaluation is conducted. Researchers are urged to use the TIDieR checklist to ensure transparent reporting of interventions and facilitate the translation of evidence to practice.
Project description:Childhood obesity remains an epidemic in the U.S. and worldwide. However, little is understood regarding the epigenetic basis of obesity in adolescents. To investigate the cross-sectional association between DNA methylation level in obesity-related genes and body mass index (BMI) percentile, data from 263 adolescents in the population-based Penn State Child Cohort follow-up exam was analysed. Using DNA extracted from peripheral leukocytes, epigenome-wide single nucleotide resolution of DNA methylation in cytosine-phosphate-guanine (CpG) sites and surrounding regions was obtained. We used multivariable-adjusted linear regression models to assess the association between site-specific methylation level and age- and sex-specific BMI percentile. Hypergeometric and permutation tests were used to determine if obesity-related genes were significantly enriched among all intragenic sites that achieved a p < 0.05 throughout the epigenome. Among the 5,669 sites related to BMI percentile with p < 0.05, 28 were identified within obesity-related genes. Obesity-related genes were significantly enriched among 103,466 intragenic sites (Phypergeometric = 0.006; Ppermutation = 0.006). Moreover, increased methylation on one site within SIM1 was significantly related to higher BMI percentile (P = 4.2E-05). If externally validated, our data would suggest that DNA methylation in obesity-related genes may relate to obesity risk in adolescents.
Project description:For youth and parents, frequent family meals have been consistently associated with positive dietary outcomes but less consistently associated with lower body mass index (BMI). Researchers have speculated dinnertime context (dinnertime routines, parent dinnertime media use) may interact with family meal frequency to impact associations with BMI. The present study evaluates the associations and interactions between dinnertime context measures and family dinner frequency with parent and child BMI. This cross-sectional study uses baseline data from the Healthy Home Offerings via the Mealtime Environment (HOME) Plus randomized control trial that aimed to prevent childhood obesity. Participants (160 parent-child dyads) completed psychosocial surveys and were measured for height and weight. General linear models tested associations and interactions between dinnertime context measures and family dinner frequency with parent and child BMI, adjusted for race and economic assistance. Lower parent dinnertime media use and higher dinnertime routines were significantly associated with lower child BMI z scores but not parent BMI scores. Interaction-moderation findings suggest higher family dinner frequency amplifies the healthful impact of the dinnertime context on child BMI z scores. Additionally, findings emphasize that promoting frequent family meals along with consistent routines and reduction in parent dinnertime media use may be important for the prevention of childhood obesity. (PsycINFO Database Record
Project description:To examine the relationships between parental patterns regarding child feeding and child body mass index (BMI) percentile in Latino parent?-preschooler dyads participating in a clinical trial.This secondary analysis examined data collected during a randomized clinical trial of a culturally tailored healthy lifestyle intervention focused on childhood obesity prevention, Salud Con La Familia. We analyzed 77 Latino parent-child dyads who completed baseline and 3-month follow-up data collection, assessing associations between preschool child BMI percentile and parental response to the Child Feeding Questionnaire (CFQ) over time.Higher child BMI was related to higher parental CFQ concern scores (r = 0.41, p < .001). A general inverse association between child BMI percentile and parental responsibility was also observed (r = -0.23, p = .040). Over the 3-month period, no statistically significant associations between changes in the CFQ subscale scores and changes in child BMI percentile were identified.Child BMI percentile consistent with overweight/obese is associated with parental concern about child weight and child BMI percentile consistent with normal weight is associated with perceived responsibility for feeding. Emphasizing parental responsibility to help children to develop healthy eating habits could be an important aspect of interventions aimed at both preventing and reducing pediatric obesity for Latino preschoolers.