Nozawa Shuhei, Urushihata Kazuhisa, Machida Ryosuke, Hanaoka Masayuki
First Department of Internal Medicine, Shinshu University School of Medicine, 3-1-1 Asahi, Matsumoto, Japan.
Sleep Biol Rhythms. 2021 Sep 14;20(1):115-121. doi: 10.1007/s41105-021-00347-4. eCollection 2022 Jan.
Obstructive sleep apnea (OSA) causes sleep-disordered breathing (SDB) due to upper airway obstruction. The severity of OSA changes with position during sleep. Patients with marked significant improvement in apnea-hypopnea index (AHI) level by sleep position change are defined as ''positional patients'' (PP), while those without improvement are defined as ''non-positional patients'' (NPP). We aimed to verify their clinical characteristics. Between May 2008 and May 2020, 237 patients with OSA were registered retrospectively and classified into two groups: PP ( = 158) and NPP ( = 79). The differences in clinical background and full-night polysomnography (PSG) between the two groups were observed. A logistic regression analysis was conducted to identify the risk factors for severe AHI (≥ 30 events/h) in the PP group. Moreover, confounding factor-adjusted sub-analysis by a propensity score matching method was performed, and the PSG results were compared between the two groups. The PP group was older than the NPP group. Furthermore, the PP group had lower body mass index (BMI) and AHI levels compared with the NPP group. The independent risk factors for severe AHI in the PP group were BMI and being in the supine position during sleep. The PP group had a significantly milder nocturnal hypoxemia despite having no significant difference in AHI levels between the two groups. The characteristics of PP were old age, low BMI, and low AHI associated with milder nocturnal hypoxemia. Moreover, they were less likely to worsen with nocturnal hypoxemia compared with NPP having similar severity.
阻塞性睡眠呼吸暂停（OSA）由于上气道阻塞导致睡眠呼吸紊乱（SDB）。OSA的严重程度在睡眠期间会随体位改变。睡眠体位改变后呼吸暂停低通气指数（AHI）水平有显著改善的患者被定义为“体位性患者”（PP），而无改善的患者被定义为“非体位性患者”（NPP）。我们旨在验证他们的临床特征。2008年5月至2020年5月，对237例OSA患者进行回顾性登记，并分为两组：PP组（n = 158）和NPP组（n = 79）。观察两组之间临床背景和全夜多导睡眠图（PSG）的差异。进行逻辑回归分析以确定PP组中重度AHI（≥30次/小时）的危险因素。此外，采用倾向评分匹配法进行混杂因素调整后的亚组分析，并比较两组的PSG结果。PP组比NPP组年龄更大。此外，与NPP组相比，PP组的体重指数（BMI）和AHI水平更低。PP组中重度AHI的独立危险因素是BMI和睡眠时处于仰卧位。尽管两组之间AHI水平无显著差异，但PP组的夜间低氧血症明显较轻。PP组的特征是年龄较大、BMI较低、AHI较低且夜间低氧血症较轻。此外，与严重程度相似的NPP组相比，他们夜间低氧血症恶化的可能性较小。
