Cerebral and Muscle Oxygenation During Intermittent Hypoxia Exposure in Healthy Humans.

Abstract

To evaluate changes in muscle and cerebral oxygenation during intermittent hypoxia (IH). Fifteen healthy subjects were exposed to 45-min IH (2-min cycles). Arterial blood oxygen saturation (SpO2), prefrontal cortex and brachial biceps muscle oxygenation (assessed by near-infrared spectroscopy), heart rate, and ventilation were continuously recorded. During 2-min IH cycles, changes in SpO2 (9.2% ± 3.3%) were associated with significant changes in cortex oxygenation (3.2% ± 1.8%), minute ventilation, and heart rate, but no change in muscle oxygenation (0.2% ± 1.0%). Fluctuations of blood oxygen levels comparable to severe obstructive sleep apnea translate into distinct pattern of oxygenation changes in the muscle and cortex.