Abstract
INTRODUCTION: Hair cortisol concentration (HCC) is a biomarker of long-term stress. Higher HCC is associated with higher adiposity in adults; however, associations are not well characterized in adolescents. OBJECTIVE: To examine cross-sectional associations of HCC with adiposity in late adolescence. METHODS: Amongst 336 non-Hispanic White participants (48.5% female, mean 17.7 years) in Project Viva, we used multivariable linear regression models, overall and sex-stratified, to estimate associations of HCC with body mass index (BMI), bioelectric impedance (BIA) percent body fat, waist circumference (WC) and dual X-ray absorptiometry-measured percent and total fat or trunk fat mass. We adjusted models for age and known predictors of adiposity. RESULTS: Median (interquartile range) HCC was 2.1 pm/mg (1.0-4.5) and mean (SD) BMI was 23.1 kg/m(2) (3.9), BIA %body fat 20.2% (9.9) and WC 80.6 cm (10.9). In adjusted models, higher HCC (per doubling) was associated with higher BMI (β = 0.19 kg/m(2); 95%CI 0.00, 0.37) and BIA percent body fat (β = 0.41%; 95%CI 0.04, 0.77). We observed no evidence of effect modification by sex. CONCLUSIONS: Higher HCC was associated with greater adiposity in late adolescence. Further research is needed to disentangle the relationship between HCC and adolescent adiposity, including the temporal direction of the relationship and sex-specific associations.