Elevated hair cortisol concentrations in children with adrenal insufficiency on hydrocortisone replacement therapy

BACKGROUND: Glucocorticoid replacement therapy in patients with adrenal insufficiency needs to be tailored to the individual patient based on body composition and clinical signs and symptoms as no objective method for assessment of treatment adequacy is available. Current treatment regimens are often not satisfactory, which is shown by the adverse metabolic profile and doubled mortality rates in treated adrenal insufficiency patients. Measurement of cortisol concentrations in hair reflect the long-term systemic cortisol exposure and may be of use in refinement of hydrocortisone treatment. OBJECTIVE: We aimed to study whether long-term cortisol (hydrocortisone) levels, as measured in scalp hair, are similar in children with adrenal insufficiency and healthy children. MATERIAL AND METHODS: We set up a case control study, measuring anthropometric characteristics and hair cortisol concentrations (HCC) in 54 hydrocortisone substituted children with adrenal insufficiency (AI patients) in the age of 4-18 years and 54 healthy children matched for gender and age. RESULTS: Mean HCC were significantly higher in AI patients compared with healthy controls (mean 13·3 vs 8·2 pg/mg, P = 0·02). AI patients also had a higher BMI (P < 0·001) and waist circumference (WC) (P = 0·02). HCC was significantly associated with BMI (P = 0·002) and WC (P = 0·002). HCC explained 13% of the difference in BMI and 29% of the difference in WC between AI patients and controls. CONCLUSION: Hydrocortisone-treated AI patients have increased HCC and adverse anthropometric characteristics compared with healthy controls. HCC measurement may be of value in identifying overtreatment and thereby improve hydrocortisone replacement therapy.