Epigenetics of Early-Life Socioeconomic Stressors and the Impact on Childhood Body Mass Index—Potential Mechanism and Biomarker?

Overweight and obesity are growing epidemics worldwide. Recent estimates from the World Health Organization indicate that 39% of adults had overweight, and 13% had obesity. In addition, an estimated 340 million children and adolescents aged 5 to 19 years had overweight or obesity in 2016 whereas 39 million children younger than 5 years had overweight or obesity in 2020. Understanding the biological mechanisms behind the development of overweight and obesity is critical as overweight and obesity are risk factors for a host of cardiometabolic outcomes including heart disease, stroke, diabetes, and chronic kidney disease. The developmental origins of health and disease hypothesis points to the importance of long-term epigenetic programming for cardiometabolic risk factors such as high body mass index (BMI) in early life. This hypothesis postulates that the risk for future overweight or obesity may be programmed during infancy or gestation. However, historically, measures of epigenetic BMI have been based on analyses from adult blood samples. Whether these measures were robust in children and could be obtained from saliva remains unclear.