Monitoring results and correlation analysis of polysomnography in 110 cases of elderly patients with obstructive sleep apnea-hypopnea syndrome / 中华老年医学杂志

ABSTRACT

Objective To improve the understanding of the characteristics of obstructive sleep apnea-hypopnea syndrome (OSAHS) in the elderly patients, and to improve the diagnosis and treatment level. Methods Monitoring results of polysomnography (PSG) from 110 elderly OSAHS patients were analyzed retrospectively. The general conditions, sleep architecture, apnea and hypopnea events, oxygen reduction as well as possible correlations between various indicators were analyzed using SPSS18.0 statistical software. Results The median rapid eye movement (REM) and non-REM (NREM) sleep time of elderly patients with OSAHS accounted for 2. 17% and 76.73%,respectively. The median arousal index was 45.6 times/h. The longest time of sleep apnea was (51.94±22.06) s, the median of average sleep apnea time was 22.50 s, the longest time of hypopnea was (47.06±12.52) s and the average hypopnca time was (21.50±4.63) s. The median respiratory disturbance index (RDI) of all patients was 21.50, the patients with RDI between 5 and 20 accounted for 46.40%, with RDI between 20 and 40 accounted for 31.80% and with RDI over 40 accounted for 21.8%. The average oxygen saturation accounted for (93.45% ± 2.81%), the lowest oxygen saturation accounted for (76.3%± 10. 5%) and the median oxygen desaturation index was 31.6;times/h. BMI was negatively correlated with lowest oxygen saturation (r=-0. 378, P＜0.01) and average oxygen saturation ( r = - 0. 355, P ＜ 0. 01 ), while was positively correlated with oxygen desaturation index (r=0. 338, P＜0. 01 ). The lowest oxygen saturation was negatively correlated with the longest time of obstructive apnea (r= -0. 47, P＜0. 01 ), the average time of obstructive apnea (r=-0.316, P＜0.01), the longest time of hypopnea (r=-0.293, P＜0.01) and the average time of hypopnea (r=-0. 277, P＜0.01). The median time intervals of oxygen desaturation during supine, left side and right side position were 2.36 min, 11.54 min and 12.45 min,respectively. The median time intervals of oxygen desaturation during left side and right side position were both longer than that of supine position (Z= -6.12 and -7. 10 respectively, both P＜0.01).Conclusions Elderly patients with OSAHS manifest obvious disorder of sleep structural and sleep fragmentation. According to RDI, the majority of the patients are classified as mild to moderate in severity. However, elderly patients with OSAHS are severe regarding to hypoxia relatively. The severity of hypoxia is related with BMI and the lasting time of sleep-disordered breathing events, and hypoxia are less severe when sleeping on left side or on right side.