Effect of continuous positive airway pressure and placebo treatment on sympathetic nervous activity in patients with obstructive sleep apnea. Export

@article{citeulike:4036723, abstract = {STUDY OBJECTIVES: We studied the effect of continuous positive airway pressure (CPAP) treatment on sympathetic nervous activity in 38 patients with obstructive sleep apnea. DESIGN: Randomized, placebo-controlled trial. SETTING: Patients underwent polysomnography on three occasions in a clinical research center, and had BP monitored over 24 h at home. All of the patients had sleep apnea with a respiratory disturbance index (RDI) > 15. INTERVENTIONS: The patients were randomized blindly to CPAP or placebo (CPAP at ineffective pressure) treatment. Measurements and results: Prior to therapy, the number of apneas and the severity of nocturnal hypoxia correlated significantly with daytime urinary norepinephrine (NE) levels, but not nighttime urinary NE levels. CPAP treatment lowered daytime BP from 99 +/- 2 mm Hg to 95 +/- 3 mm Hg (mean +/- SEM) and nighttime BP from 93 +/- 3 mm Hg to 88 +/- 3 mm Hg. Placebo CPAP treatment decreased both day and night mean BP only 2 mm Hg. CPAP, but not placebo, treatment lowered daytime plasma NE levels by 23\%, daytime urine NE levels by 36\%, daytime heart rate by 2.6 beats/min, and increased lymphocyte beta(2)-adrenergic receptor sensitivity (all p < 0.05). The effect of CPAP treatment on nighttime urine NE levels and heart rate did not differ from placebo treatment. There was a suggestion of an effect of placebo CPAP treatment on nighttime measures, but not on daytime measures. CONCLUSION: We conclude that daytime sympathetic nervous activation is greater with more severe sleep apnea. CPAP treatment diminished the daytime sympathetic activation; the potential nighttime effect of CPAP treatment was obscured by a small placebo effect.}, author = {Ziegler, M. G. and Mills, P. J. and Loredo, J. S. and Ancoli-Israel, S. and Dimsdale, J. E.}, citeulike-article-id = {4036723}, citeulike-linkout-0 = {http://view.ncbi.nlm.nih.gov/pubmed/11555525}, citeulike-linkout-1 = {http://www.hubmed.org/display.cgi?uids=11555525}, issn = {0012-3692}, journal = {Chest}, keywords = {cell\_signaling, norepinephrine, obstructive\_sleep\_apnea, sympathetic\_activation}, month = {September}, number = {3}, pages = {887--893}, posted-at = {2009-02-11 20:40:36}, priority = {2}, title = {Effect of continuous positive airway pressure and placebo treatment on sympathetic nervous activity in patients with obstructive sleep apnea.}, url = {http://view.ncbi.nlm.nih.gov/pubmed/11555525}, volume = {120}, year = {2001} }

TY - JOUR ID - citeulike:4036723 L3 - citeulike-article-id:4036723 N2 - STUDY OBJECTIVES: We studied the effect of continuous positive airway pressure (CPAP) treatment on sympathetic nervous activity in 38 patients with obstructive sleep apnea. DESIGN: Randomized, placebo-controlled trial. SETTING: Patients underwent polysomnography on three occasions in a clinical research center, and had BP monitored over 24 h at home. All of the patients had sleep apnea with a respiratory disturbance index (RDI) > 15. INTERVENTIONS: The patients were randomized blindly to CPAP or placebo (CPAP at ineffective pressure) treatment. Measurements and results: Prior to therapy, the number of apneas and the severity of nocturnal hypoxia correlated significantly with daytime urinary norepinephrine (NE) levels, but not nighttime urinary NE levels. CPAP treatment lowered daytime BP from 99 +/- 2 mm Hg to 95 +/- 3 mm Hg (mean +/- SEM) and nighttime BP from 93 +/- 3 mm Hg to 88 +/- 3 mm Hg. Placebo CPAP treatment decreased both day and night mean BP only 2 mm Hg. CPAP, but not placebo, treatment lowered daytime plasma NE levels by 23%, daytime urine NE levels by 36%, daytime heart rate by 2.6 beats/min, and increased lymphocyte beta(2)-adrenergic receptor sensitivity (all p < 0.05). The effect of CPAP treatment on nighttime urine NE levels and heart rate did not differ from placebo treatment. There was a suggestion of an effect of placebo CPAP treatment on nighttime measures, but not on daytime measures. CONCLUSION: We conclude that daytime sympathetic nervous activation is greater with more severe sleep apnea. CPAP treatment diminished the daytime sympathetic activation; the potential nighttime effect of CPAP treatment was obscured by a small placebo effect. IS - 3 JF - Chest SN - 0012-3692 EP - 893 TI - Effect of continuous positive airway pressure and placebo treatment on sympathetic nervous activity in patients with obstructive sleep apnea. VL - 120 SP - 887 KW - cell_signaling KW - norepinephrine KW - obstructive_sleep_apnea KW - sympathetic_activation AU - Ziegler, MG AU - Mills, PJ AU - Loredo, JS AU - Ancoli-Israel, S AU - Dimsdale, JE PY - 2001/09// UR - http://view.ncbi.nlm.nih.gov/pubmed/11555525 ER -