Associations of hair cortisol concentrations with general and organ fat measures in childhood.
Stress may lead to an adverse body fat distribution from childhood onwards.To examine the associations of hair cortisol concentrations (HCC) at 6 years with general and organ fat measures, risk of overweight and nonalcoholic fatty liver disease (NAFLD) at 10 years and to assess whether these were independent of adiposity measures at 6 years.HCC were measured in hair of 6-year old children (n = 2,042) participating in the Generation R Study, a population-based prospective cohort study.BMI, fat mass index (FMI) measured by DXA scan, and visceral fat index, pericardial fat index, liver fat fraction measured by MRI and risk of overweight and NAFLD were obtained at 10 years.The associations of higher HCC at 6 years, with higher BMI, FMI and increased risk of overweight at age 10 years are explained by the relationships observed at 6 years. HCC at 6 years were associated with a higher liver fat fraction (difference 0.11 liver fat fraction standard deviation score (SDS) (95% Confidence Interval (CI) 0.03, 0.18)) and a higher risk of NAFLD at 10 years (OR: 1.95 (95% CI 1.06, 3.56), independent of FMI at 6 years. HCC were not associated with pericardial or visceral fat indices.Higher HCC at 6 years were associated with higher BMI, FMI, liver fat fraction, and higher risks of overweight and NAFLD at 10 years. Only the associations for liver fat fraction and NAFLD were independent of FMI at 6 years.