Continuous positive airway pressure treatment improves pulmonary hemodynamics in patients with obstructive sleep apnea.

Daytime pulmonary hypertension (PH) is relatively common in obstructive sleep apnea (OSA) and is thought to be associated with pulmonary vascular remodeling (PRm). The extent to which PH is reversible with treatment is uncertain. To study this, we measured pulmonary hemodynamics (Doppler echocardiography) in 20 patients with OSA (apnea-hypopnea index [AHI] 48.6 +/- 5.2/h, mean +/- SEM) before and after 1 and 4 mo of CPAP treatment (compliance 4.7 +/- 0.5 h/night). Patients had normal lung function, and no cardiac disease or systemic hypertension. Doppler studies were performed at three levels of inspired oxygen concentration (11%, 21%, and 50%) and during incremental increases in pulmonary blood flow (10, 20, and 30 microg/kg/min dobutamine infusions). Treatment resulted in a decrease in pulmonary artery pressure (Ppa, 16.8 +/- 1.2 mm Hg before CPAP versus 13.9 +/- 0.6 mm Hg after 4 mo CPAP, p < 0.05) and total pulmonary vascular resistance (231.1 +/- 19.6 versus 186.4 +/- 12.3 dyn. s. cm(-)(5), p < 0.05). The greatest treatment effects occurred in the five patients who were pulmonary hypertensive at baseline. The pulmonary vascular response to hypoxia decreased after CPAP (DeltaPpa/DeltaSa(O(2)) 10.0 +/- 1.6 mm Hg before versus 6.3 +/- 0.8 mm Hg after 4 mo CPAP, p < 0.05). The curve of Ppa versus cardiac output (Q), derived from the incremental dobutamine infusion, shifted downward in a parallel fashion during treatment. Systemic diastolic blood pressure also fell significantly. Improvements in pulmonary hemodynamics were not attributable to changes in left ventricular diastolic function or Pa (O(2)). We conclude that CPAP treatment reduces Ppa and hypoxic pulmonary vascular reactivity in OSA and speculate that this may be due to improved pulmonary endothelial function.     

持续气道内正压治疗阻塞性睡眠呼吸暂停低通气综合征

持续气道内正压（CPAP）通气是治疗阻塞性睡眠呼吸暂停低通气综合征（OSAHS）的主要方法。OSAHS患者经CPAP治疗后嗜睡改善、血压下降、心脑血管病变的发生率降低，生活质量提高。CPAP治疗OSAHS的主要机制是气道内正压使上气道撑开^[1]，并且由于呼气时气道内正压使肺残气增高，也有助于维持上气道的畅通。     

Continuous positive airway pressure improves nocturnal baroreflex sensitivity of patients with heart failure and obstructive sleep apnea

OBJECTIVES: To determine the acute effects of continuous positive airway pressure (CPAP) on baroreceptor reflex sensitivity (BRS) for heart rate during sleep in congestive heart failure (CHF) patients with obstructive sleep apnea (OSA). DESIGN AND METHODS: In eight CHF patients with OSA not previously treated with CPAP, spontaneous BRS was assessed during overnight polysomnography prior to the onset of sleep, and during stage 2 non-rapid eye movement sleep (NREM) before, during and after application of CPAP. RESULTS: CPAP alleviated OSA and acutely increased the slope of BRS (median, 25%,75%) [from 3.9 (3.5, 4.8) to 6.2 (4.6, 26.2) ms/mmHg, P<0.05]. Increases in the slope of BRS persisted following withdrawal of CPAP [4.9 (4.3, 6.9) ms/mmHg, P<0.05]. CPAP also lowered heart rate (from 81.3 +/- 4.9 to 76.0 +/- 5.7 bpm, P< 0.05), an effect which persisted after its withdrawal (76.7 +/- 5.7 bpm, P < 0.05). Systolic blood pressure at the midpoint of the pressure range of BRS sequences fell while on CPAP (from 139 +/- 8 to 120 +/- 7 mmHg, P < 0.05), and remained lower following CPAP withdrawal (124 +/- 9 mmHg, P < 0.05). CONCLUSIONS: In CHF patients with OSA, CPAP increases acutely BRS during sleep, lowers heart rate and resets the operating point for BRS to a lower blood pressure. These effects of CPAP persist after its withdrawal, suggesting that nocturnal CPAP therapy may cause sustained improvement in the neural control of heart rate.     

Continuous positive airway pressure treatment improves baroreflex control of heart rate during sleep in severe obstructive sleep apnea syndrome

The role of the arterial baroreflex in the cardiovascular changes associated with the obstructive sleep apnea syndrome (OSAS), and the effect of nasal continuous positive airway pressure (CPAP) treatment on baroreflex function during sleep are unknown. Baroreflex control of heart rate was studied in 29 normotensive patients with OSAS under no treatment, in 11 age-matched control subjects, and in 10 patients at CPAP withdrawal after 5.5 +/- 3.7 (range 3-14) months of treatment. Baroreflex control of heart rate was assessed by "sequence method" analysis of continuous blood pressure recordings (Finapres) obtained during nocturnal polysomnography. In untreated OSAS, baroreflex sensitivity (BRS) was low during wakefulness and non-rapid eye movement (REM) stage 2 sleep compared with control subjects, and correlated inversely with mean lowest Sa(O(2)) and the blood pressure increase after apneas. After CPAP treatment, the apnea-hypopnea index was lower, and mean lowest Sa(O(2)) higher than before treatment. After CPAP, patients were more bradycardic, blood pressure and its standard deviation decreased as Sa(O(2)) improved in non-REM stage 2 sleep, and BRS increased (nocturnal wakefulness: +59%; non-REM stage 2 sleep: +68% over pretreatment values). Our data suggest that baroreflex dysfunction in OSAS may be at least partly accounted for by nocturnal intermittent hypoxemia, and can be reversed by long-term CPAP treatment.     

Continuous positive airway pressure treatment on blood pressure rhythm in hypertension patients with obstructive sleep apnea

<正>Objective To investigate the effect of continuous positive airway pressure(CPAP) on blood pressure and blood pressure rhythm in hypertensive patients with sleep apnea syndrome.Methods Hypertensive patients with obstructive sleep apnea syndrome consecutively recruited between 2020 and 2022 were randomly divided into two groups,the CPAP group and the control group.Both groups were routinely treated with antihypertensive drugs,and patients in the CPAP group were additionally treated with C...     

Continuous positive airway pressure improves daytime baroreflex sensitivity and nitric oxide production in patients with moderate to severe obstructive sleep apnea syndrome.

Individuals with obstructive sleep apnea syndrome (OSAS) are at high risk for cardiovascular morbidity and mortality. The effects of OSAS severity and nocturnal continuous positive airway pressure (CPAP) on daytime baroreflex sensitivity (BRS) and nitric oxide (NO) production were investigated in OSAS patients. Fifty-one consecutive males with OSAS and 29 age-matched healthy men underwent the Valsalva test and standard polysomnography. Patients with an apnea-hypopnea index (AHI) of >or=20 episodes per hour were randomized to receive CPAP treatment for 3 months (n=14) or no such treatment (n=19). The BRS index measured from the overshoot phase (phase IV) of the Valsalva maneuver and plasma NO concentration were significantly lower, whereas the AHI, oxygen desaturation time, arousal index, percentage of sleep stage 1, and systolic blood pressure were significantly greater, in patients with an AHI of >or=20/h than in those with an AHI of <20/h or in controls. The 24-h urinary excretion of norepinephrine was significantly reduced and the plasma NO concentration was significantly increased after one night of CPAP. The BRS index for phase IV and the Valsalva ratio were significantly increased in the CPAP group after the 3-month treatment period but remained unchanged in the non-CPAP group of OSAS patients. The daytime BRS index and NO production were thus inversely related to the severity of OSAS, and successful CPAP treatment improved these parameters in patients with moderate to severe OSAS. CPAP may therefore reduce the risk of cardiovascular complications due to endothelial dysfunction or increased sympathetic activity.     

Positional treatment vs continuous positive airway pressure in patients with positional obstructive sleep apnea syndrome

OBJECTIVES: The aim of this study was to compare the relative efficacy of continuous positive airway pressure (CPAP) and positional treatment in the management of positional obstructive sleep apnea (OSA), using objective outcome measures. DESIGN: A prospective, randomized, single blind crossover comparison of CPAP and positional treatment for 2 weeks each. SETTING: A university teaching hospital. PATIENTS: Thirteen patients with positional OSA, aged (mean+/-SD) 51+/-9 years, with an apnea-hypopnea index (AHI) of 17+/-8. MEASUREMENTS: (1) Daily Epworth Sleepiness Scale scores; (2) overnight polysomnography, an objective assessment of sleep quality and AHI; (3) maintenance of wakefulness testing; (4) psychometric test battery; (5) mood scales; (6) quality-of-life questionnaires; and (7) individual patient's treatment preference. RESULTS: Positional treatment was highly effective in reducing time spent supine (median, 0; range, 0 to 32 min). The AHI was lower (mean difference, 6.1; 95% confidence interval [CI], 2 to 10.2; p = 0.007), and the minimum oxygen saturation was higher (4%; 95% CI, 1% to 8%; p = 0.02) on CPAP as compared with positional treatment. There was no significant difference, however, in sleep architecture, Epworth Sleepiness Scale scores, maintenance of wakefulness testing sleep latency, psychometric test performance, mood scales, or quality-of-life measures. CONCLUSION: Positional treatment and CPAP have similar efficacy in the treatment of patients with positional OSA.     

Continuous positive airway pressure therapy improves vascular dysfunction and decreases oxidative stress in patients with the metabolic syndrome and obstructive sleep apnea syndrome

Background:

Patients with obstructive sleep apnea syndrome (OSAS) are always exposed to intermittent hypoxia and reoxygenation. The metabolic syndrome (MetS) and OSAS are also known to accelerate atherosclerosis, diabetes, and dyslipidemia. Therefore, nasal continuous positive airway pressure (CPAP) therapy may have beneficial effects in patients with the MetS and OSAS.

Hypothesis:

This study in patients with the MetS and OSAS tested the validity of the hypothesis that chronic CPAP therapy improves factors involved in atherosclerosis, including impaired endothelial function.

Methods:

Thirty‐two patients (19 males and 13 females, mean age 54 ± 9 y) diagnosed with the MetS and OSAS were enrolled in the study and received CPAP therapy for 3 months. Vascular function was investigated by measuring forearm blood flow (FBF) responses to reactive hyperemia (RH) using venous occlusion strain‐gauge plethysmography. Biochemical markers were also measured before and after this procedure.

Results:

Basal apnea‐hypopnea index was statistically correlated with FBF response to RH. The FBF response to RH was increased significantly after 3 months of CPAP therapy. A significant increase in plasma nitric oxide levels and a decrease in the levels of asymmetrical dimethylarginine, thiobarbituric acid reactive substance, soluble Fas ligand, and soluble CD40 ligand were detected after CPAP therapy. The plasma concentrations of tumor necrosis factor‐α, interleukin (IL)‐6, and IL‐8 also decreased significantly with CPAP therapy, whereas IL‐1β levels remained unchanged.

Conclusions:

Continuous positive airway pressure therapy has beneficial effects on vascular function and inflammatory and oxidative stress in patients with the MetS and OSAS. The authors have no funding, financial relationships, or conflicts of interest to disclose.     

连续气道正压通气对男性阻塞性睡眠呼吸暂停患者自主神经调制的影响

目的 探讨连续气道正压通气(CPAP)对阻塞性睡眠呼吸暂停低通气综合征(OSAHS)患者自主神经调制的影响.方法 选择OSAHS患者60例和对照组25例,对所有受试者进行多导睡眠图及动态心电图监测,采用时域分析法分析患者心率变异性以评价自主神经调制功能.对OSAHS患者使用CPAP治疗3个月后再次评估自主神经调制功能.结果 与对照组相比,OSAHS组自主神经调制功能指标正常RR间期标准差(SDNN)、RR间期差值均方根(rMSSD)、每5分钟节段平均正常RR间期标准差(SDANN)和高频功率(HF)均低于对照组,且与呼吸紊乱指数呈负相关;低频功率(LF)和低频与高频之比(LF/HF)高于对照组,与呼吸紊乱指数呈正相关.LF/HF值与呼吸紊乱指数和最低血氧饱和度呈线性回归关系.结论 OSAHS患者存在自主神经调制功能损害,与呼吸紊乱指数和低氧有关;经CPAP治疗后,OSAHS患者自主神经调制功能损害明显改善,且对CPAP耐受良好.     

Arbitrary-pressure continuous positive airway pressure for obstructive sleep apnea syndrome

Current resources are inadequate to meet the demand for polysomnography, resulting in long waiting lists. This study aimed to evaluate the role of arbitrary-pressure continuous positive airway pressure (CPAP) as a method to reduce delays in commencing treatment. The study was of an open, randomized, parallel design. Ninety-one subjects with obstructive sleep apnea syndrome were randomized to either arbitrary-pressure CPAP based on body mass index before treatment polysomnography or to CPAP at settings determined by polysomnography. Both interventions resulted in similar improvements in clinical outcomes as determined by Epworth Sleepiness Score, Short Form-36 Quality of Life questionnaire, objective compliance, and subjective attitudes to treatment. There was higher sleep efficiency at treatment polysomnography in the group commenced at arbitrary pressure (81.8 +/- 10.1% [mean +/- SD] compared with 72.2 +/- 18.0%, p = 0.01). Subjects unable to tolerate CPAP were identified by the use of arbitrary pressure, leading to a reduction in the proportion of "wasted" treatment polysomnograms (studies performed in subjects not persisting with treatment) relative to commencing therapy after treatment polysomnography (3 of 39 compared with 12 of 35, p = 0.01). This approach to initiating treatment with CPAP appears feasible when there are long waiting lists for polysomnography.     

连续气道正压通气对阻塞性睡眠呼吸暂停患者血管内皮功能的影响

目的检测阻塞性睡眠呼吸暂停低通气综合征（OSAHS）患者血清一氧化氮（NO）、内皮素-1（ET-1）、血管性血友病因子（vWF）及肱动脉内径变化;评估连续气道正压通气（CPAP）对此类患者血管内皮功能的影响。方法选择OSAHS患者55例和健康对照组55例,分别测定所有受试者血清NO、ET-1、vWF水平,同时使用多普勒彩超测定肱动脉内径变化。对OSAHS患者使用CPAP治疗3月后再次测定以上指标。结果治疗前OSAHS患者血清NO水平和肱动脉内径变化率明显低于对照组（P均〈0．01）;血清ET-1和vWF水平明显高于对照组（P均〈0．01）。NO水平和肱动脉内径变化率与呼吸紊乱指数呈显著负相关（r分别为-0．621,-0．581,P〈0．01）,与最低血氧饱和度正相关（r分别为0．516,0．613,P〈0．01）;ET-1和vWF水平与呼吸紊乱指数呈正相关（r分别为0．534,0．559,P均〈0．01）,与最低血氧饱和度均呈负相关（r分别为-0．479,-0．637,P均〈0．01）。肱动脉内径变化率与NO呈正相关,与ET-1和vWF水平呈负相关（r分别为0．681,-0．541和-0．513,P均〈0．01）。结论OSAHS患者早期已存在血管内皮功能损害,与呼吸紊乱指数和低氧相关;CPAP能够改善患者血管内皮功能。     

持续气道正压通气治疗对OSAHS患者血液流变学的影响

目的探讨阻塞性睡眠呼吸暂停低通气综合征(OSAHS)患者经鼻持续气道正压通气(ncpap)治疗对其血液流变学指标的影响。方法随机选择我科确诊为中度或重度OSAHS的患者30例,其中男20例,女10例,年龄45~68岁,平均年龄(58±3)岁,治疗前14d内未服用过非甾体类消炎药及阿斯匹林,潘生丁等抗凝剂,并排除其它呼吸系疾病、紫绀性先心病、肾脏疾病及原发性红细胞增多症,分别于治疗前及治疗30d后检测血细胞比容、全血比粘度(高切度、中切度、低切度),红细胞聚集指数。结果治疗后血细胞比容、全血比粘度(高切度、中切度、低切度)、红细胞聚集指数较治疗前显著降低(P<0.01)。结论OSAHS存在显著血栓栓塞高危因素,ncpap对其有明显防治作用。     

持续气道正压治疗对阻塞性睡眠呼吸暂停患者夜间多尿症状的影响

目的研究持续气道正压（CPAP）治疗对阻塞性睡眠呼吸暂停综合征（OSAS）患者夜间多尿症状的影响。方法15例多导睡眠图（PSG）确诊的OSAS患者,记录CPAP治疗前后的夜尿次数、夜尿量、夜尿渗透压和夜尿钠排泄量,测定其中8例患者治疗前后夜间（23时、02时、05时）心钠素（ANP）水平。结果(1)CPAP治疗后OSAS患者夜尿次数明显减少（P<0.01）。(2)夜尿量由(0.078±0.017)L/h降至(0.052±0.011)L/h（P<0.01）。(3)CPAP治疗后OSAS患者夜尿渗透压由(381±96)mmol/L明显增高至(570±169)mmol/L（P<0.05）。(4)CPAP治疗后OSAS患者夜尿钠的排泄量由(1.16±0.35)mmol/h降至(0.63±0.13)mmol/h（P<0.01）。(5)8例患者CPAP治疗前后的夜间ANP平均水平分别为(146±14)ng/L和(106±10)ng/L,两者相比差异有显著性(P<0.01)。(6)8例测定ANP患者在CPAP治疗后ANP降低值与该患者夜尿量降低值、夜尿渗透压增高值、夜尿钠排泄量减少值均有显著的正相关,相关系数分别为0.82、0.84、0.81(P均<0.01)。结论CPAP治疗可明显减少OSAS患者夜尿次数和夜尿量,减少夜尿钠排泄量,增加夜尿渗透压,这些改变可能与ANP水平降低有关。     

Effects of exercise training associated with continuous positive airway pressure treatment in patients with obstructive sleep apnea syndrome

Purpose

The aim of this study was to evaluate the effects of a 2-month exercise training associated with continuous positive airway pressure (CPAP) treatment on the subjective and objective sleep measurements, quality of life, and mood in moderate to severe obstructive sleep apnea syndrome (OSAS) patients.

Methods

Male patients were randomized into two treatment groups: CPAP (n?=?19) and CPAP?+?exercise (n?=?13). All patients completed 1?month of sleep hygiene, 2?months of treatment (CPAP or CPAP?+?exercise), and 1?week of washout (no treatment). Fletcher and Luckett sleep questionnaire, Epworth sleepiness scale, sleep diaries, polysomnography, SF-36 inventory of quality of life, Profile of Mood States (POMS) questionnaire, neck circumference, and body composition were evaluated. CPAP?+?exercise group also underwent cardiopulmonary exercise test before and after treatment.

Results

Both treatments were effective in improving subjective sleepiness but CPAP?+?exercise treatment was more effective in maintaining this improvement after washout. No significant differences were found in most of the sleep parameters studied in both groups. CPAP?+?exercise group showed lower values of tension and fatigue on POMS and higher values of physical functioning, general health perception, and vitality on SF-36 after treatment.

Conclusions

A 2-month exercise training associated with CPAP treatment for OSAS patients has a positive impact on subjective daytime sleepiness, quality of life (physical functioning and general health perception), and mood state (tension and fatigue).