Effect of nocturnal hypoxia on pulmonary hemodynamics in patients with obstructive sleep apnea

Effects of apnoea induced nocturnal hypoxia on pulmonary haemodynamics (PH) in pts with OSA are still under debate. We studied PH in 67 pts (64 M and 3 F) mean +/- SD: age 45 +/- 8 years, with severe OSA, AHI 62 +/- 22. Patients had normal spirometry: FVC 98 +/- 15% N, FEV1 97 +/- 16% N and arterial blood gases--PaO2 72 +/- 10 mmHg, PaCO2 40 +/- 4 mmHg. PH were studied using Swan-Ganz thermodilution catheter. PH were within normal range: right atrial pressure 4.2 +/- 2.7 mmHg, right ventricular systolic/enddiastolic pressure 28.1 +/- 7.1/5.0 +/- 3.3 mmHg, mean pulmonary artery pressure (PAP) 15.8 +/- 4.6 mmHg, mean pulmonary wedge pressure (PW) 6.8 +/- 3.1 mmHg, cardiac output (CO) 5.6 +/- 2.2 L/min. and pulmonary vascular resistance (PVR) 150 +/- 83 dyn.sec.cm-5. During exercise (44 pts) PAP rose from 15.8 +/- 4.3 to 29.8 +/- 9.4 mmHg, PW rose from 6.8 +/- 3.2 to 12.6 +/- 6.8 mmHg and CO from 4.9 +/- 1.9 to 9.2 +/- 4.2 L/min. All patients presented with nocturnal desaturations. Mean oxygen saturation (SaO2 mean) was: 87.4 +/- 5.4%, minimal saturation (SaO2 min) was 57.4 +/- 15.9%. Time spent in desaturation SaO2 < 90% (T90) was 50.7 +/- 26.5%. Results of PH investigations were related to results of pulse oximetry. Linear regression analysis showed week negative correlations between SaO2 mean and: PAP (r = -0.37 p = 0.003), PVR (r = -0.37 p = 0.007), and positive correlation between T90 and PAP (r = 0.37 p = 0.008). We conclude that there is no diurnal pulmonary hypertension at rest in patients with severe OSA and normal lung function even in the presence of severe overnight nocturnal desaturations. In half of studied patients we observed pulmonary hypertension during exercise.     

Hypercapnia and sleep O2 desaturation in chronic obstructive pulmonary disease

There is a wide clinical spectrum in chronic obstructive pulmonary disease (COPD). The extremes of this spectrum, the "pink puffer" (PP) and "blue bloater" (BB) stereotypes differ in their degree of sleep hypoxemia and pulmonary hypertension. Most patients cannot be characterized as either PP or BB. The data amassed in the recent nocturnal oxygen therapy trial provide an opportunity to see to what extent differences in sleep oxygenation and hemodynamics in a large hypoxemic COPD population are related to awake hypoxemia and hypercapnia. From a large hypoxemic COPD population sleep SaO2 was examined in those with (PaCO2 greater than 44 mm Hg) and without (PaCO2 less than or equal to 44 mm Hg) hypercapnia. Hypercapnic patients (mean PaCO2 49.8 mm Hg) had the same PaO2 and degree of airflow obstruction as normocapnic patients (PaCO2 37.4 mm Hg) but had far greater sleep hypoxemia (measured by mean sleep SaO2, low sleep SaO2, and awake-low sleep SaO2, p less than 0.05). In addition, arterial blood gases of the large sleep O2 desaturaters were compared with those of the small desaturaters; PaO2 was similar in both groups, whereas PaCO2 was different (p less than 0.01). Two common subsets of hypoxemic patients were also compared; one was hypercapnic and overweight, the other normocapnic and hyperinflated. We found that patients in the hypercapnic group had far worse sleep hypoxemia, although they had better lung function. We conclude that hypercapnia is a marker for sleep O2 desaturation in hypoxemic COPD.     

Atrial natriuretic excretion in patients with obstructive sleep apnea syndrome (OSAS)

During obstructive sleep apneas stimuli, that may increase excretion of atrial natriuretic peptide (ANP) occur. The aim of the study was the evaluation whether in patients with OSAS levels of ANP are significantly different in relation to sleep or wakefulness and in relation to disturbances of ventilation during sleep and wakefulness. The material of the study consisted of 34 patients with OSAS (age 25-65 years). There were no differences in the levels of ANP late in the evening, during sleep and early in the morning. There were 2 groups of the patients: with low (< 70 pg/ml, mean at 21 p.m. 9.7 +/- 8.7 pg/ml, at. 2 a.m. 12.5 +/- 9.3 pg/ml, at 6 a.m. 14.4 +/- 15.1 pg/ml) and high (> 70 pg/ml, mean at 21 p.m. 148.6 +/- 232.9 pg/ml, at 2 a.m. 119.5 +/- 45.5 pg/ml, at 6 a.m. 164.9 +/- 161 pg/ml) ANP levels. As compared with patients with low ANP levels, patients with high ANP levels were older and more obese, more frequently had concomitant COPD, lower VC and FEV1, higher daytime PaCO2 and lower PaO2; most of them had peripheral edema. In patients with high ANP levels there was more profound mean arterial blood desaturation during sleep apnoeas than in patients with low ANP levels (SaO2 75 +/- 8% vs 81 +/- 4%, p < 0.001), although apnea index and mean apnea duration were similar in both groups. CONCLUSIONS: In patients with OSAS the daytime and sleep levels of ANP are similar. High levels of ANP can be found in OSAS patients with impaired daytime ventilation and gas exchange, and profound arterial oxygen desaturation during sleep apnoeas.     

Oxygen desaturation during night sleep affects decision‐making in patients with obstructive sleep apnea

This study assessed decision‐making and its associations with executive functions and sleep‐related factors in patients with obstructive sleep apnea. Thirty patients with untreated obstructive sleep apnea and 20 healthy age‐ and education‐matched controls performed the Iowa Gambling Task, a decision‐making task under initial ambiguity, as well as an extensive neuropsychological test battery. Patients, but not controls, also underwent a detailed polysomnographic assessment. Results of group analyses showed that patients performed at the same level of controls on the Iowa Gambling Task. However, the proportion of risky performers was significantly higher in the patient group than in the control group. Decision‐making did not correlate with executive functions and subjective ratings of sleepiness, whereas there was a significant positive correlation between advantageous performance on the Iowa Gambling Task and percentage of N2 sleep, minimal oxygen saturation, average oxygen saturation and time spent below 90% oxygen saturation level. Also, the minimal oxygen saturation accounted for 27% of variance in decision‐making. In conclusion, this study shows that a subgroup of patients with obstructive sleep apnea may be at risk of disadvantageous decision‐making under ambiguity. Among the sleep‐related factors, oxygen saturation is a significant predictor of advantageous decision‐making.     

The relationship of daytime hypoxemia and nocturnal hypoxia in obstructive sleep apnea syndrome

QUESTION OF THE STUDY: Prevalence and determinants of daytime hypoxemia in patients with obstructive sleep apnea (OSA) syndrome are not well established. The aims of this study, conducted in a large series of OSA patients, were to estimate the prevalence of daytime hypoxemia, to assess the reciprocal effects between daytime PaO2 and nocturnal SpO2, and to investigate the direct and indirect role of sleep apnea severity in determining feedback gas exchange abnormalities. MATERIALS AND METHODS: In 456 patients a daytime hypoxemia-nocturnal hypoxia feedback structural equations model was designed. PaO2 adjusted for age (% of predicted), percent sleep time spent with SpO2 <90% (TST90), oxygen desaturation index and the apnea-hypopnea index, were determined as the measures of daytime hypoxemia, nocturnal hypoxia, and sleep apnea severity, respectively, after adjusting for the severity of obesity and lung volumes. RESULTS: The TST90-PaO2 feed-back structural equations modeling showed that daytime PaO2 was inversely related (P<0.001) to nocturnal hypoxia (-4.0% of PaO2 per 1 SD of TST90). The severity of OSA (-1.0%) was an indirect determinant of daytime PaO2 via the TST90 pathway. In contrast, daytime PaO2 did not influence (P>0.05) the extent of nocturnal hypoxia. CONCLUSIONS: In OSA patients, the extent of nocturnal hypoxia seems to be both a direct determinant and a mediator of the indirect effect of sleep apnea on the development of daytime hypoxemia.     

Mean platelet volume is associated with disease severity in patients with obstructive sleep apnea syndrome

OBJECTIVE:Obstructive sleep apnea syndrome is associated with cardiovascular diseases and thromboembolic events. The mean platelet volume (MPV) is a predictor of cardiovascular thromboembolic events. The aim of the present study is to investigate the association between the MPV and disease severity in patients with obstructive sleep apnea syndrome.METHODS:We prospectively included 194 obstructive sleep apnea syndrome patients without cardiovascular disease (mean age 56.5±12.5 years) who were undergoing sleep tests. An overnight full laboratory polisomnography examination was conducted on each patient. The patients were divided into 3 groups according to the apnea-hypopnea index (AHI): (1) AHIlow group: 5≤AHI<15, (2) AHImid group: 15<AHI≤30, and (3) AHIhigh group: AHI>30.RESULTS:The highest MPV values were found in the AHIhigh group compared with other groups (p<0.05 for all). Multiple linear regression analysis indicated that the MPV was associated with the AHI (β=0.500, p<0.001) and the high sensitivity C-reactive protein (hs-CRP) level (β=0.194, p=0.010).CONCLUSION:The MPV is independently associated with both disease severity and inflammation in patients with obstructive sleep apnea syndrome.     

有氧运动训练对稳定期慢性阻塞性肺疾病伴睡眠障碍患者肺功能和睡眠质量的干预效果

目的:探究有氧运动训练对稳定期慢性阻塞性肺疾病(chronic obstructive pulmonary disease,COPD)伴睡眠障碍患者肺功能和睡眠质量的干预效果.方法:选取2019年4月至2021年3月阜阳市第二人民医院收治的104例稳定期COPD伴睡眠障碍患者,采用随机数表法分成对照组(52例)与试验组...     

无创正压通气对夜间慢性阻塞性肺疾病患者呼吸力学和睡眠紊乱的影响

目的 探讨无创正压通气(NIPPV)对夜间慢性阻塞性肺疾病(COPD)患者呼吸力学和睡眠紊乱的影响.方法 选择南方医科大学珠江医院呼吸内科自2010年10月至2011年10月收治的COPD急性加重期住院患者16例,常规肺通气功能测定,经过NIPPV治疗病情稳定后,分别在患者自主呼吸和NIPPV时睡眠状态下进行呼吸力学和多导睡眠图的监测,连续采集并计算各项呼吸和睡眠参数.结果 COPD患者睡眠状态下,NIPPV与自主呼吸相比较,呼吸频率(RR)差异无统计学意义(P＞0.05);潮气量(VΥ)由(0.35±0.10)L升高到(0.45±0.12)L、每分钟通气量(VE)由(6.17±1.15) L/min升高到(7.97±2.34) L/min、平均吸气流量(VΥ/Ti)由(0.24±0.09) L/s升高到(0.39±0.11) L/s、动态肺顺应性(CLdyn)由(43.46±12.75) ml/cm H2O(1cm H2O=98 Pa)升高到(60.23±17.31) ml/cm H2O、指脉氧饱和度(SpO2)由(83.55±5.07)％升高到(95.67±5.38)％,差异均有统计学意义(P＜0.05～P＜0.001);吸气时间占呼吸周期比值(Ti/Ttot)由0.43±0.11降低到0.33±0.08、气道阻力(Raw)由(25.64±6.02) cm H2O/L-1·s-1降低到(20.34±3.67) cm H2O/L-1·s-1、压力-时间乘积(PTP)由(423.12±89.06) cm H2O· s-1·min-1降低到(170.44±41.53) cm H2O· s-1· min-1、呼气末二氧化碳分压(PETCO2)由(63.74±8.45) mm Hg(1 mm Hg=0.133 kPa)降低到(45.32±5.74) mm Hg,差异均有统计学意义(P＜0.05～ P＜0.001).睡眠效率(SEF％)由(74.23±12.78)％升高到(84.41±15.11)％、快速动眼睡眠时间占总睡眠时间百分比(REM/TST％)由(12.16±7.38)％升高到(19.35±9.41)％、慢波睡眠占总睡眠时间百分比(SWS/TST％)由(5.38±3.35)％升高到(13.68±7.25)％、夜间基础指脉氧饱和度(SpO2％base)由(84.77±4.97)％升高到(96.46±4.32)％、夜间最低指脉氧饱和度(SpO2％lowest)由(75.03±6.32)％升高到(85.78±4.84)％,差异均有统计学意义(P＜0.05);睡眠潜伏期(SLT)由(63.32±25.26) min降低到(30.57±8.02) min、微觉醒指数由(38.24± 17.57)次/h降低到(25.66±15.78)次/h、呼吸暂停低通气指数(AHI)由(3.63±0.76)次/h降低到(2.51±0.67)次/h、呼吸紊乱最长时间(BDLon)由(40.02±8.83)s降低到(21.37±5.66)s、指脉氧饱和度低于90％时间占总睡眠时间百分比(SpO2％＜90％/TST％)由(29.36±9.74)％降低到(17.72±5.27)％,差异均有统计学意义(P＜0.05).结论 NIPPV可显著改善睡眠状态下COPD患者的呼吸力学异常,降低了气道阻力和呼吸做功,改善了COPD患者夜间低氧和低通气状态,一定程度上改变了COPD患者的异常睡眠结构,纠正了睡眠紊乱,睡眠质量显著提高.     

Haptoglobin polymorphism is a risk factor for cardiovascular disease in patients with obstructive sleep apnea syndrome

STUDY OBJECTIVES: Obstructive sleep apnea syndrome is associated with a marked increase in the risk for cardiovascular disease. Increased oxidative stress and leukocyte adhesiveness have been implicated as fundamental pathophysiologic mechanisms underlying the increased susceptibility in these patients. Haptoglobin is an antioxidant and immunomodulatory protein encoded by 2 alleles with profoundly different biophysical and biochemical properties. We therefore sought to determine if the haptoglobin phenotype was a determinant of cardiovascular disease in patients with obstructive sleep apnea syndrome. DESIGN: Haptoglobin phenotype was determined by gel electrophoresis in 465 patients with and 757 individuals without obstructive sleep apnea syndrome. SETTING: Eight-bed Technion Sleep Medicine Center in Haifa, serving the northern part of Israel. PARTICIPANTS: Patients referred for sleep recordings because of suspected breathing disorders in sleep and healthy industry workers. MEASUREMENTS AND RESULTS: Patients with obstructive sleep apnea syndrome and cardiovascular disease had a significantly different distribution of the 3 haptoglobin phenotypes as compared to patients with obstructive sleep apnea syndrome but without cardiovascular disease. No difference in the haptoglobin phenotype frequency was found between controls with and without cardiovascular disease. Log linear analysis revealed a significant interaction effect of haptoglobin phenotype and the presence of sleep apnea on the presence of cardiovascular disease. Logistic regression analysis revealed that the risk of cardiovascular disease in sleep apnea patients younger than 55 years with haptoglobin 2-2 was 2.32-fold higher than in their counterparts with haptoglobin 2-1. CONCLUSIONS: These results suggest that haptoglobin phenotype is an important risk factor in determining susceptibility to cardiovascular disease in obstructive sleep apnea syndrome, which may be mediated by the decreased antioxidant and antiinflammatory actions of the haptoglobin 2 allelic protein product.     

Arginase activity and nitric oxide levels in patients with obstructive sleep apnea syndrome

OBJECTIVE:

Obstructive sleep apnea syndrome is characterized by repetitive obstruction of the upper airways, and it is a risk factor for cardiovascular diseases. There have been several studies demonstrating low levels of nitric oxide in patients with obstructive sleep apnea syndrome compared with healthy controls. In this study, we hypothesized that reduced nitric oxide levels would result in high arginase activity. Arginase reacts with L-arginine and produces urea and L-ornithine, whereas L-arginine is a substrate for nitric oxide synthase, which produces nitric oxide.

METHODS:

The study group consisted of 51 obstructive sleep apnea syndrome patients (M/F: 43/8; mean age 49±10 years of age) and 15 healthy control subjects (M/F: 13/3; mean age 46±14 years of age). Obstructive sleep apnea syndrome patients were divided into two subgroups based on the presence or absence of cardiovascular disease. Nitric oxide levels and arginase activity were measured via an enzyme-linked immunosorbent assay of serum samples.

RESULTS:

Serum nitric oxide levels in the control subjects were higher than in the obstructive sleep apnea patients with and without cardiovascular diseases (p<0.05). Arginase activity was significantly higher (p<0.01) in obstructive sleep apnea syndrome patients without cardiovascular diseases compared with the control group. Obstructive sleep apnea syndrome patients with cardiovascular diseases had higher arginase activity than the controls (p<0.001) and the obstructive sleep apnea syndrome patients without cardiovascular diseases (p<0.05).

CONCLUSION:

Low nitric oxide levels are associated with high arginase activity. The mechanism of nitric oxide depletion in sleep apnea patients suggests that increased arginase activity might reduce the substrate availability of nitric oxide synthase and thus could reduce nitric oxide levels.     

Improvement of sleep apnea in patients with chronic renal failure who undergo nocturnal hemodialysis

BACKGROUND: Sleep apnea is common in patients with chronic renal failure and is not improved by either conventional hemodialysis or peritoneal dialysis. With nocturnal hemodialysis, patients undergo hemodialysis seven nights per week at home while sleeping. We hypothesized that nocturnal hemodialysis would correct sleep apnea in patients with chronic renal failure because of its greater effectiveness. METHODS: Fourteen patients who were undergoing conventional hemodialysis for four hours on each of three days per week underwent overnight polysomnography. The patients were then switched to nocturnal hemodialysis for eight hours during each of six or seven nights a week. They underwent polysomnography again 6 to 15 months later on one night when they were undergoing nocturnal hemodialysis and on another night when they were not. RESULTS: The mean (+/-SD) serum creatinine concentration was significantly lower during the period when the patients were undergoing nocturnal hemodialysis than during the period when they were undergoing conventional hemodialysis (3.9+/-1.1 vs. 12.8+/-3.2 mg per deciliter [342+/-101 vs. 1131+/-287 micromol per liter], P<0.001). The conversion from conventional hemodialysis to nocturnal hemodialysis was associated with a reduction in the frequency of apnea and hypopnea from 25+/-25 to 8+/-8 episodes per hour of sleep (P=0.03). This reduction occurred predominantly in seven patients with sleep apnea, in whom the frequency of episodes fell from 46+/-19 to 9+/-9 per hour (P= 0.006), accompanied by increases in the minimal oxygen saturation (from 89.2+/-1.8 to 94.1+/-1.6 percent, P=0.005), transcutaneous partial pressure of carbon dioxide (from 38.5+/-4.3 to 48.3+/-4.9 mm Hg, P=0.006), and serum bicarbonate concentration (from 23.2+/-1.8 to 27.8+/-0.8 mmol per liter, P<0.001). During the period when these seven patients were undergoing nocturnal hemodialysis, the apnea-hypopnea index measured on nights when they were not undergoing nocturnal hemodialysis was greater than that on nights when they were undergoing nocturnal hemodialysis, but it still remained lower than it had been during the period when they were undergoing conventional hemodialysis (P=0.05). CONCLUSIONS: Nocturnal hemodialysis corrects sleep apnea associated with chronic renal failure.     

阻塞性睡眠呼吸暂停综合征患者轻度认知功能障碍的MoCA评估

目的 探讨简易精神状态检查量表(MMSE)、蒙特列尔认知评估量表(MoCA)评估阻塞性睡眠呼吸暂停综合征(OSAS)患者轻度认知功能障碍(MCI)的可行性.方法 用便携式多导睡眠仪、MMSE及MoCA对51名OSAS患者和35名单纯鼾症者进行睡眠监测和认知功能的评价.结果 OSAS组MoCA评分结果为21.1 ±3.0,显著低于对照组的25.0 ±2.6(P＜0.01);MMSE评分结果在OSAS组与对照组中分别为27.8±1.8及28.1±1.7,无统计学意义.结论 MoCA对于OSAS患者MCI的早期诊断敏感性优于MMSE,对于MMSE测试结果正常但高度怀疑存在MCI者,MoCA是一种简便可行的筛查工具.     

阻塞性睡眠呼吸暂停综合征患者手术前后腭咽测量及临床意义

目的 :为阻塞性睡眠呼吸暂停综合征 (OSAS)患者的病源定位 ,悬雍垂腭咽成形术 (UPPP)手术范围的确定和术后疗效的评定提供依据。方法 :对 2 0例正常人及 45例OSAS患者UPPP术前、术后腭咽部进行解剖测量并将相关数据进行对照分析。结果 :正常人和OSAS患者所测腭咽解剖指标分别为 :软腭长 (2 7.6 8± 7.17)mm ,(2 9.94± 4.71)mm(P <0 .0 5 ) ;悬壅垂宽 (8.40± 1.18)mm ,(10 .74± 1.6 8)mm(P <0 .0 1) ;悬雍垂长 (10 .2 0± 2 .85 )mm ,(11.94± 2 .48)mm(P <0 .0 1) ;咽侧距 (2 3 .70± 7.0 5 )mm ,(19.87± 4.40 )mm(P <0 .0 5 ) ;腭咽距 (12 .36± 3 .97)mm ,(9.80± 2 .90 )mm(P <0 .0 1) ,均存在显著差异。UPPP参照正常人腭咽指标保留软腭长度获得良好的手术效果 ,同时控制了并发症的发生。结论 :腭咽测量法简便实用 ,病源定位准确 ,使手术选择和切除范围更为合理 ,有助于提高疗效。