Sleep quality under mild hypoxia in men with low hypoxic ventilatory response

Abstract The present study evaluated whether slow-wave sleep and whole-night delta power of the non-rapid eye movement (NREM) sleep electroencephalogram (EEG) decrease during sleep at a simulated altitude of 2000 m, and whether such changes related to measures of hypoxic ventilatory response (HVR). This study consisted of two parts; in the first, HVR was measured in 41 subjects and each seven subjects with the lowest or the highest HVR were selected for the subsequent sleep study. In the second part, polysomnogram, arterial oxygen saturation (SpO2) and respiratory events are recorded on the selected subjects under normoxic and hypoxic conditions. Hypoxia decreased SpO2 and increased respiratory disturbances for both groups. The low HVR group, but not the high HVR group, showed decreases in the whole-night delta power of NREM sleep EEG under hypoxia. On the other hand, two subjects in the high HVR group, who showed relatively high apnoea indices, also showed lower SpO2 nadirs and decreases in the whole-nig...