Oxytocin and Genetic Links with Eating Behaviours and Relevant Endophenotypes

Oxytocin (OXT) is an ancestral neuropeptide hormone essential in the regulation of human behaviours vital for sustaining life such as food intake and reproduction. Importantly, these behaviours have strong associations with the brains reward circuitry. To date, there has been little OXT-genetic research in the field of eating behaviors. However, a recent study by Davis et al. (2017) identified several single nucleotide polymorphisms (SNPs) on the OXT receptor gene (OXTR), associated with overeating and relevant behaviours. The present study expanded on this work by analyzing SNPs of the LNPEP, CD38, and OXTG genes. Additionally, sex differences were also examined. A pre-existing data set consisting of 460 healthy volunteers was used in the study. A series of two-way MANOVAs were employed and results indicated nonsignificant main effects for genotype on all 12 SNPs. However, multivariate tests for sex were significant in each analysis. Possible explanations for the current findings are discussed.