High 6-year hair cortisol concentration tied to larger fat measures in childhood

Higher hair cortisol concentration (HCC) at 6 years correlates with higher body mass index (BMI), fat mass index, liver fat fraction, and increased risks of overweight and nonalcohol fatty liver disease (NAFLD) at 10 years, a study has found. Only the associations for liver fat fraction and NAFLD are independent of fat mass index at 6 years.

The investigators examined the associations of HCC at 6 years with general and organ fat measures, risk of overweight, and NAFLD at 10 years, and determined whether these were independent of adiposity measures at 6 years. They measured HCC in the hair of 6-year-old children (n=2,042) included in the Generation R Study, a population-based prospective cohort study.

At 10 years, the investigators obtained data on BMI, fat mass index measured by dual-energy X-ray absorptiometry scan, and visceral fat index, pericardial fat index, liver fat fraction measured by magnetic resonance imaging, and risk of overweight and NAFLD.

The associations of higher HCC at 6 years with higher BMI, fat mass index, and elevated risk of overweight at age 10 years were driven by the correlations observed at 6 years.

Specifically, HCCs at 6 years correlated with a higher liver fat fraction (difference, 0.11 liver fat fraction standard deviation score, 95 percent confidence interval [CI], 0.03–0.18) and a higher risk of NAFLD at 10 years (odds ratio, 1.95, 95 percent CI, 1.06–3.56), independent of fat mass index at 6 years. HCCs, on the other hand, showed no association with pericardial or visceral fat indices.

“Stress may lead to an adverse body fat distribution from childhood onwards,” the investigators said.