Oxygen desaturation rate as a novel intermittent hypoxemia parameter in severe obstructive sleep apnea is strongly associated with hypertension

Abstract

Study Objectives: To investigate the effects of different intermittent hypoxemia properties on blood pressure (BP) and short-term blood pressure variability (BPV) in severe obstructive sleep apnea (OSA) patients. Methods: Nocturnal BP was continuously monitored by measuring pulse transmit time. Apnea-related systolic BP elevation values were used to reflect BPV. Beat-to-beat R-R interval data were incorporated in polysomnography for heart rate variability analysis. The low-frequency/high-frequency band ratio was used to reflect sympathovagal balance. The rate of pulse oxyhemoglobin saturation (SpO2) decrease was counted as the change in the percentage of SpO2 per second after obstructive apnea and expressed as the oxygen desaturation rate (ODR). Patients with severe OSA (n = 102) were divided into 2 groups according to the median ODR: Faster ODR (FODR group: ODR > 0.37, n = 50) and slower ODR (ODR ≤ 0.37, n = 52). Results: Comparisons between the 2 groups showed significantly higher systolic BP (SBP) values in the FODR group than in the slower ODR group (awake SBP 149.9 ± 18.3 vs 131.8 ± 15.6 mm Hg; asleep SBP: 149.6 ± 19.9 vs 128.7 ± 15.6 mm Hg; both P