Unlocking the Secrets: Fresh Perspectives on Childhood Obesity’s Biology and Risk Factors

Childhood obesity represents a significant public health issue: 1 in 10 children in Europe suffer from obesity, placing them at elevated risk for metabolic disorders and heart diseases later on. Despite its widespread occurrence, the biological processes underlying obesity-related health dilemmas remain inadequately understood, and not every child with obesity develops metabolic complications.

To fill this void, scientists employed a sophisticated “multi-layered omics” methodology to investigate gene expression, proteins, and metabolites gathered from blood samples of over 800 European children, alongside comprehensive data about their health and prenatal surroundings. “Prenatal stages are particularly crucial as environmental exposures during this vital developmental phase can have substantial implications later in life,” articulates Martine Vrijheid, ISGlobal researcher and lead author of the study.

This research is part of the Human Early Life Exposome (HELIX) initiative, which tracks groups of children from Northern Europe (Bradford, UK; and Poitiers, France) as well as Southern Europe (Sabadell, Spain; and Heraklion, Greece).

A vulnerable cluster of children

Through the analysis of five “omics” dimensions—DNA methylation, microRNAs, mRNA, proteins, and metabolites—the scientists discovered three distinct clusters among the children. One of these clusters distinguished itself as the children not only exhibited increased body fat but also demonstrated more indications of metabolic challenges. This vulnerable cluster displayed an elevated expression of inflammation markers, which signify an overly active immune response.

“Many of these inflammatory substances can induce insulin resistance and activate a chronic inflammatory cycle,” elucidates first author Nikos Stratakis. “By concentrating on clusters derived from multi-omics profiles, our approach offers enhanced insights into the biological pathways relevant to metabolic health, surpassing traditional clinical indicators,” he further states.

Environmental risk factors in early life

The researchers also investigated environmental influences during gestation and discovered that the mother’s weight prior to pregnancy significantly affected the likelihood of her child belonging to the high-risk group. Notably, the environmental exposures associated with the high-risk cluster varied by region. In Northern and Western Europe, maternal exposure to the industrial chemical perfluorooctanoate (utilized in non-stick coatings) emerged as a key risk factor. Conversely, in Southern / Mediterranean Europe, maternal exposure to mercury, likely from increased fish consumption, was recognized as a risk factor.

“These results assist us in identifying modifiable risk factors that could be addressed early in life,” states Vrijheid. “They also highlight the necessity to customize prevention strategies to cater to diverse regional contexts,” she adds.