Are peripheral biomarkers determinants of eating styles in childhood and adolescence obesity? A cross-sectional study

Disturbances in eating behaviors have been widely related to obesity. However, little is known about the role of obesity-related biomarkers in shaping habitual patterns of eating behaviors (i.e., eating styles) in childhood. The objective of the present study was to explore the relationships between several biomarkers crucially involved in obesity (ghrelin, insulin resistance, and leptin/adiponectin ratio) and eating styles in children and adolescents with obesity. Seventy participants aged between 8 and 16 (56.2% men) fulfilled the Spanish version of the Dutch Eating Behavior Questionnaire for Children to measure external, emotional, and restrained eating styles. In addition, concentrations of ghrelin, leptin, adiponectin, insulin, and glucose were obtained through a blood test. Hierarchical multiple regression analyses controlling for age and sex were computed for each eating style. Results indicated that individuals with higher ghrelin concentration levels showed lower scores in restrained eating (beta = -0.61, p < 0.001). The total model explained 32% of the variance of the restrained pattern. No other relationships between obesity-related biomarkers and eating behaviors were found. This study highlights that one of the obesity-risk factors, namely lower plasma ghrelin levels, is substantially involved in a well-known maladaptive eating style, restraint eating, in childhood obesity

Longitudinal study of DNA methylation during the first 5 years of life.

Background: Early life epigenetic programming influences adult health outcomes. Moreover, DNA methylation levels have been found to change more rapidly during the first years of life. Our aim was the identification and characterization of the CpG sites that are modified with time during the first years of life. We hypothesize that these DNA methylation changes would lead to the detection of genes that might be epigenetically modulated by environmental factors during early childhood and which, if disturbed, might contribute to susceptibility to diseases later in life. Methods: The study of the DNA methylation pattern of 485577 CpG sites was performed on 30 blood samples from 15 subjects, collected both at birth and at 5 years old, using Illumina® Infinium 450 k array. To identify differentially methylated CpG (dmCpG) sites, the methylation status of each probe was examined using linear models and the Empirical Bayes Moderated t test implemented in the limma package of R/Bioconductor. Surogate variable analysis was used to account for batch effects. Results: DNA methylation levels significantly changed from birth to 5 years of age in 6641 CpG sites. Of these, 36.79 % were hypermethylated and were associated with genes related mainly to developmental ontology terms, while 63.21 % were hypomethylated probes and associated with genes related to immune function. Conclusions: Our results suggest that DNA methylation alterations with age during the first years of life might play a significant role in development and the regulation of leukocyte-specific functions. This supports the idea that blood leukocytes experience genome remodeling related to their interaction with environmental factors, underlining the importance of environmental exposures during the first years of life and suggesting that new strategies should be take into consideration for disease prevention