Saliva is a practical way to assess the risk of pre–school children for obesity, and thus may present an opportunity for prevention or early intervention, researchers at Vanderbilt University School of Medicine reported Jan. 9 in the journal BMC Genomics.

In a first–of–its–kind study, Shari Barkin, MD, MSHS, and colleagues collected saliva samples from 92 Hispanic pre–school children. DNA in the samples was tested for methylation, an epigenetic mechanism that regulates expression of genes, including those affecting accumulation of adipocytes (fat cells) and other obesity risk factors.

Methylation at 17 DNA sites was found to be significantly associated with the mother’s body mass index (BMI), suggesting that obesity risk may be transmitted from mother to child. Inadequate nutrition or insulin resistance in the mother, for example, may cause epigenetic changes favoring obesity in the child.

If validated by further study, these “epigenetic signatures” could aid discovery of early biomarkers of childhood obesity and metabolic dysfunction, the researchers concluded.