Hypothalamic-Pituitary-Adrenal Axis Activation in Obstructive Sleep Apnea: The Effect of Continuous Positive Airway Pressure Therapy

Context: Obstructive sleep apnea (OSA) is a common condition with significant cardiovascular and metabolic comorbidity. We hypothesized that these may result from OSA-induced perturbations of endogenous ultradian hypothalamic-pituitary-adrenal axis activity. Objective: The aim of the study was to investigate ACTH and cortisol ultradian patterns using an automated, repetitive blood sampling technique. Design: Samples for ACTH and cortisol were collected from 10 patients with moderate to severe OSA under basal conditions, at 10-min intervals over 24 h, at diagnosis and 3 months after compliant continuous positive airway pressure (CPAP) therapy. Multiple-parameter deconvolution estimated specific measures of ACTH and cortisol pulsatile secretion from blood hormone concentrations. Results: Mean total ACTH and cortisol production were elevated pre-CPAP compared to post-CPAP (ACTH, 1459.8 ± 123.0 vs. 808.1 ± 97.9 pg/ml, P < 0.001; cortisol, 5748.9 ± 364.9 vs. 3817.7 ± 351.7 nmol/liter, P < 0.001) as were mean t...