Abstract
Impaired cerebral blood blow during wakefulness at rest as well as reduced exercise tolerance have been reported in severe obstructive sleep apnoea (OSA) patients. Impaired cerebral oxygenation can contribute to reduced exercise performance. We hypothesized that i) OSA patients show impaired cerebral hemodynamics pattern during exercise together with reduced exercise tolerance and ii) continuous positive airway pressure (CPAP) treatment improves these alterations in cerebral oxygenation.
Fifteen OSA patients and 12 healthy matched controls performed a maximal cardiopulmonary exercise test before and after 8 weeks of CPAP treatment or control period. Prefrontal cortex and muscle oxygenation were assessed by near-infrared spectroscopy.
Reduced prefrontal cortex oxygen extraction and total blood volume (i.e. lower increase in deoxyhemoglobin ([HHb]) [1.76±1.57 vs 3.43±2.08 µmol; p<0.001] and total hemoglobin ([HbTot]) [5.36±7.08 vs 8.55±5.13 µmol at exhaustion; p=0.046], respectively) during exercise together with a reduced exercise tolerance (i.e. lower peak oxygen consumption (VO2peak): 24.1±5.3 vs 33.1± 9.7 mL·min·kg-1; p<0.001) were observed in OSA patients compared to controls. VO2peak correlated with prefrontal cortex [HHb] and [HbTot] at exhaustion (r=0.68, p<0.001; r=0.46, p=0.015, respectively). CPAP treatment only induced a slight improvement in cerebral tissue saturation index during exercise.
This study demonstrates that cerebrovascular response to exercise is altered in OSA and likely contributes to exercise intolerance in these patients. Prefrontal cortex oxygenation and exercise tolerance are not significantly improved following 8 weeks of CPAP treatment.
Footnotes
Cite this article as: European Respiratory Journal 2018 52: Suppl. 62, OA480.
This is an ERS International Congress abstract. No full-text version is available. Further material to accompany this abstract may be available at www.ers-education.org (ERS member access only).
- Copyright ©the authors 2018