Heritability of BMI Stronger in Obesogenic Environments
Modifying early home environment to prevent weight gain may be important for children genetically at risk for obesity.
Obesity-related genes in children show a stronger association with body mass index (BMI) in obesogenic environments, according to study results published in JAMA Pediatrics.
In conducting this study, researchers relied on a gene environment study of twins to examine the influence of early obesogenic home environments on childhood BMI. They referenced cross-sectional data from 925 families (1850 twins) from a population-based prospective cohort of twins. The parents participated in a home environment interview which measured the obesogenic home environment in the twins' early childhood. To create an obesogenic risk score, researchers focused on food, physical activity, and media influence data from the interviews. They used a quantitative genetic model fitting to approximate heritability of age- and sex-adjusted BMI for children living in different risk environments.
Per previous analyses, children of lower socioeconomic status showed higher BMI heritability. Among the 1850 children who participated in this study, 49.5% were male and 50.5% were female with a median age of 4.1 years. Heritability of BMI score was significantly higher in children living in high-risk environments compared with those living in low-risk environments (86% vs 39%, respectively). Children living in high-risk home environments also had a significantly higher risk scores in the food (P <.001), physical activity (P <.001), and media (P <.001) environment composites compared with children living in low-risk environments.
According to the researchers, "these findings support the hypothesis that obesity-related genes are more strongly associated with BMI in more obesogenic home environments." Additionally, these findings may provide insight into the dynamics underlying obesity and ultimately obesity prevention in children.
Schrempft S, van Jaarsveld CHM, Fisher A, et al. Variation in the heritability of child body mass index by obesogenic home environment [published online October 1, 2018]. JAMA Pediatr. doi:10.1001/jamapediatrics.2018.1508