ABSTRACT
Objective: We examined associations of different adipositymeasures with cortisol responses during the Trier Social StressTest for children (TSST-C).Design: Descriptive study.Setting: Holdsworth Memorial Hospital, Mysore, India.Participants: Adolescents aged 13.5y from a birth cohort wererecruited (N=269, 133 boys).Methods: The stressor (TSST-C) was 5-minutes each of publicspeaking and mental arithmetic tasks in front of two unfamiliar‘judges’. Salivary cortisol concentrations were measured atbaseline and at regular intervals after TSST-C. Weight, height,sub scapular and triceps skinfold thickness, and waist and hipcircumference were measured, and percentage body fat wasestimated (fat%; bioimpedance). Body mass index (BMI) andWaist-to-hip ratio (WHR) were calculated. All variables wereconverted into within-cohort SD scores before analysis. Stress-induced change in cortisol concentrations from baseline (cortisolresponse) was examined in relation to adiposity.Results: Stress increased cortisol concentrations significantlyfrom baseline (mean (SD): 5.5 (6.4) ng/mL; P<0.001). HigherWHR was associated with lower cortisol response at 20 and 30-minutes after stress (~0.13 SD decrease in cortisol response perSD higher WHR, P<0.05). Higher fat% was also associated withlower cortisol response only in girls 20-minutes post-stress (0.23SD lower response per SD higher fat%, P=0.004). Sum of skinfoldthickness and BMI were not associated with cortisol responses.Conclusions: Abdominal adiposity is associated with reducedhypothalamic-pituitary-adrenal axis reactivity to stress in thisadolescent population.