An FTO Gene Variant and Sedentary Behaviour in Children

Purpose:

To examine any potential differences in the time spent sedentary at 11 and 13 years old in relation to a variant in the fat mass and obesity (FTO) gene. Secondly, to examine the changes in sedentary behaviour between 11 and 13 years old in relation to a variant in the FTO gene.

Background:

Genome-wide association studies have provided resounding evidence that variants in the FTO gene are associated with obesity. For instance, per A allele for the single nucleotide polymorphism (SNP) - rs9939609 - has been extensively associated with an increased odds of being obese, defined by several obesity phenotypes (1). The mechanisms whereby this gene induces the increased fat mass are now being investigated. Due to the FTO gene being highly expressed within the hypothalamus, hypotheses concerning energy intake have been developed and there is evidence that those with the risk allele may consume more energy (2). In terms of energy expenditure there have been contrasting reports with null (3) and positive (4) associations found between FTO gene variants and self-reported physical activity. While these initial reports are intriguing, the clinical measurements are far from robust. Specifically analysing the association between rs9939609 genotypes and sedentary behaviour, assessed by accelerometry, while adjusting for moderate-to-vigorous physical activity (MVPA), could reveal further insight into the role of the FTO gene in energy expenditure.