Associations Between Characteristics of Obstructive Sleep Apnea and Nocturnal Blood Pressure Surge

Research suggests that oxygen desaturation and sleep stage during obstructive sleep apnea (OSA) are related to the magnitude of high blood pressure (BP) in a laboratory setting. However, in a clinical setting, these associations have not been well studied. We used a noninvasive oscillometric BP measurement device to investigate the association between oxygen-triggered BP levels at the end of each OSA episode and the characteristics of the preceding OSA episode. In 42 newly diagnosed OSA patients (average age, 63.5±12.5 years; average apnea-hypopnea index, 32.6±18.2 per hour), 258 BP measurements were obtained at the end of OSA episodes. Hypoxia-peak systolic BP (SBP), defined as the maximum oxygen-triggered SBP value, was significantly higher in rapid eye movement sleep (144.9±19.9 mm Hg) than in non–rapid eye movement stage 1 sleep (129.5±15.1 mm Hg; P<0.001) and non–rapid eye movement stage 2 sleep (129.4±14.7 mm Hg; P<0.001). In a multivariate-linear mixed model, the lowest oxygen saturation percentage...