Endocrine responses during CPAP-withdrawal in obstructive sleep apnea: data from two randomised controlled trials

Background: Obstructive sleep apnea (OSA) is associated with an increased risk of cardiovascular burden, but the underlying mechanisms are not well understood. The aim of this investigation was to elucidate the effect of continuous positive airway pressure(CPAP)-withdrawal on neurometabolic and cardiometabolic markers in OSA.Methods: We evaluated 70 patients (mean age 61±10 years, 82% male)treated with CPAP for>1 year with high compliance in two 2-week, parallel, randomised controlled trials. Blood samples were taken at baseline in the morning prior to CPAP interruption, and after two weeks of CPAP withdrawal. Samples were analysed using liquid chromatography tandem mass spectrometry. Treatment effects were determined using a regression analysis that was adjusted for baseline parameters.Findings: OSA did recur in the CPAP-withdrawal group (mean change apnea-hypopnea-index+31.8 events/hour, 95%CI +22.8 to+40.6, p<0.001)but remained controlled in the CPAP group. Samples revealed that 3,4- dihydroxyphenylglycol(DHPG), norepinephrine(NE)and cortisol increased after two weeks of CPAP-withdrawal(mean change DHPG+123.324 pg/ml, 95%CI +32.275 to+214.374, p=0.009, mean change NE +76.37 pg/ml, 95%CI +22.48 to+130.27,p=0.006, mean change cortisol +24.190 ng/ml, 95%CI +2.546 to+45.835, p=0.029). No statistically significant changes of the renin-angiotensin-aldosterone-system(RAAS)determinants were documented.Interpretation: CPAP-withdrawal resulted in elevated NE, DHPG, and ...
Source: European Respiratory Journal - Category: Respiratory Medicine Authors: Tags: Sleep and control of breathing Source Type: research