Effect of continuous positive airway pressure vs placebo continuous positive airway pressure on sleep quality in obstructive sleep apnea

STUDY OBJECTIVES: Continuous positive airway pressure (CPAP) therapy has become the treatment of choice for obstructive sleep apnea (OSA). However, the efficacy of CPAP therapy has not been evaluated against a suitable control. We investigated the effectiveness of CPAP therapy in improving sleep quality in patients with OSA. We hypothesized that CPAP improves sleep quality. PATIENTS: Forty-eight CPAP-naive OSA patients were evaluated. None were receiving antihypertensive medications, and none had major medical illnesses. DESIGN: Patients were randomized to receive either CPAP or placebo CPAP (CPAP at an ineffective pressure) for 7 days in a double-blind fashion. Forty-one patients completed the protocol. Sleep quality variables, arousals, sleep arterial oxygen saturation (SaO(2)), and respiratory disturbance index (RDI) were assessed at baseline, after 1 day of treatment, and after 7 days of treatment. Repeated measures analysis of variance was used to evaluate the effects of treatment, time, and the interaction of the two. RESULTS: As expected, CPAP lowered RDI and number of arousals, and increased SaO(2) over time (p = 0.001). Contrary to expectations, both CPAP and placebo CPAP had comparable effects on sleep quality as assessed by sleep architecture, sleep efficiency, total sleep time, and wake after sleep onset time. CONCLUSIONS: This study confirms the effectiveness of CPAP in lowering the number of arousals and the RDI, and in raising SaO(2). However, our data suggest that short-term CPAP is no different than placebo in improving sleep architecture. Further evaluation of the effectiveness of CPAP using a suitable placebo CPAP in prospective randomized studies is needed     

经鼻持续气道正压通气对阻塞性睡眠呼吸暂停综合征的综合疗效

经鼻持续气道正压通气（CPAP）是目前治疗阻塞性呼吸暂停综合征（OSAS）最有效的内科治疗方法,通过向气道内增加一定程度的正压,保持上气道通畅,消除患者夜间缺氧,改善患者夜间打鼾,白天嗜睡等临床症状,恢复睡眠结构,并治疗与此相关的各系统疾病,提高患者长期的生活质量。     

Efficacy of continuous positive airway pressure on arrhythmias in obstructive sleep apnea patients

The purpose of this study was to determine the relationship between obstructive sleep apnea (OSA) and cardiovascular disorders in a large Japanese population, and to assess the efficacy of continuous positive airway pressure (CPAP) in the treatment of OSA-associated arrhythmias. The study population comprised 1394 Japanese subjects (1086 men and 308 women) who were divided into four groups on the basis of polysomnography (PSG) analysis as follows: the no sleep apnea (N-SA) group (n = 44, apnea-hypopnea index [AHI] < 5), the mild OSA (Mi-OSA) group (n = 197, 5 < AHI < 15), the moderate OSA (Mo) group (n = 368, 15 < AHI < 30), and severe OSA (SOSA) group (n = 785, AHI < 30). The following baseline characteristics were significantly associated with OSA: age (P < 0.001), gender (P < 0.001), body mass index (P < 0.001), hypertension (P < 0.001), diabetes (P = 0.009), and hyperlipidemia (P = 0.013). In the OSA group, PSG revealed the predominance of paroxysmal atrial fibrillation (PAF) (P = 0.051), premature atrial complex short run (P < 0.005), premature ventricular complex (PVC, P = 0.004), sinus bradycardia (P = 0.036), and sinus pause (arrest >2 s, P < 0.001) during the PSG recording. A total of 316 patients from the group underwent CPAP titration and were then re-evaluated. Continuous positive airway pressure therapy significantly reduced the occurrences of PAF (P < 0.001), PVC (P = 0.016), sinus bradycardia (P = 0.001), and sinus pause (P = 0.004). The results of this study demonstrate a significant relationship between OSA and several cardiac disorders, and also demonstrate the efficacy of CPAP in preventing OSA-associated arrhythmias in a large population of Japanese patients.     

Prediction of continuous positive airway pressure in obstructive sleep apnea

Continuous positive airway pressure (CPAP) prediction formulas can potentially simplify the treatment of obstructive sleep apnea (OSA). However, they can be difficult to derive and validate. We tested a statistical method to derive and validate a CPAP prediction formula using the same sample population. Seventy-six OSA patients underwent polysomnography and CPAP titration. Anthropometric measures, sleep parameters, and the Epworth sleepiness scale (ESS) were evaluated as predictors. All subsets regression was used to determine the optimum number of variables in the model. The Bayes information criterion was used to find the best-fit model. The model was then evaluated by a tenfold cross-validation procedure. Subjects were obese (BMI 31.3 ± 5.4) and had significant daytime somnolence (ESS 11.9 ± 5). Mean respiratory disturbance index (RDI) was 53.5 ± 31.3. The ESS was not predictive of titrated CPAP. The best-fit model included three variables (CPAP_pred = 30.8 + RDI × 0.03 − nadir saturation × 0.05 − mean saturation × 0.2). This model explained 67% of the variance. Our data and the literature suggest that a combination of two to three factors is predictive of titrated CPAP: RDI, oxyhemoglobin saturation, and obesity. Except for RDI, the specific factors vary in each population. A CPAP prediction formula that explains a high proportion of the titrated CPAP variance can be easily derived from parameters measured during the diagnostic work-up of OSA patients using a unique statistical model that allows derivation and validation of the formula in the same test population.     

Neuropsychologic symptoms in obstructive sleep apnea improve after treatment with nasal continuous positive airway pressure

To describe the affective changes associated with sleep restoration we assessed psychologic symptoms using the Profile of Mood States questionnaire before and two months after treatment with nasal continuous positive airway pressure (NCPAP) in seven men with obstructive sleep apnea (OSA). The results were compared with those of a control group of patients with OSA who did not receive NCPAP. Two of six mood factors, depression and fatigue, improved significantly following treatment with NCPAP. Total Mood Disturbance (TMD) score was used to assess global mood differences. The mean TMD score for the patients before treatment was 1.7 and during treatment decreased to -7.6 (p less than 0.05). This mean decrease of 9.3 in the TMD score implies generalized improvement in mood. These findings support the opinion that sleep fragmentation and abnormalities of respiration during sleep are at least partially responsible for affective changes seen in sleep apnea. These psychologic disturbances improve after treatment with NCPAP.     

Effect of continuous positive airway pressure on albuminuria in patients with obstructive sleep apnea: a meta-analysis

Purpose

A relationship between albuminuria and obstructive sleep apnea (OSA) has been documented in previous studies. Nevertheless, the impact of continuous positive airway pressure (CPAP) treatment on albuminuria in subjects with OSA is debated. This meta-analysis was carried out to investigate whether or not CPAP treatment affected urinary albumin-to-creatinine ratio (UACR) in subjects with OSA.

Methods

A comprehensive literature search was conducted on Web of Science, Embase, and PubMed from January 1990 to December 2020. Information on patients’ characteristics, features of the studies, and UACR of pre- and post-CPAP treatment was collected. For estimation of the pooled effects, standardized mean difference (SMD) was applied.

Results

This meta-analysis included 6 articles and 211 subjects. The pooled analysis suggested that CPAP therapy exerted a favorable effect on the decrease of UACR in subjects with OSA (SMD?=?0.415, 95% CI?=?0.026 to 0.804, z?=?2.09, p?=?0.037). Subgroup analyses revealed that the CPAP treatment effect was not influenced by sample size, BMI, age, or AHI.

Conclusion

The present meta-analysis indicated that UACR was significantly reduced by CPAP therapy in subjects with OSA. Further well-designed randomized controlled trials with large sample size are required to confirm the benefits.

     

Effect of nocturnal nasal continuous positive airway pressure on blood pressure in obstructive sleep apnea

Obstructive sleep apnea (OSA) is a very common risk factor for hypertension, and continuous positive airway pressure (CPAP) has been widely used to treat OSA. We conducted a meta-analysis of randomized, controlled trials to evaluate the effects of CPAP on blood pressure, reported as either a primary or secondary end point, among patients with OSA. Studies were retrieved by searching Medline (January 1980 to July 2006), the Cochrane Database of Systematic Reviews, conference abstracts, and bibliographies of review and original articles. From 255 relevant reports, 16 randomized clinical trials were selected that compared CPAP to control among participants with OSA, had a minimum treatment duration of 2 weeks, and reported blood pressure changes during the intervention or control period. Data on sample size, participant characteristics, study design, intervention methods, duration, and treatment results were independently abstracted by 2 investigators using a standardized protocol. Data from 16 trials representing 818 participants were examined using a random-effects model. Mean net change in systolic blood pressure for those treated with CPAP compared with control was -2.46 mm Hg (95% CI: -4.31 to -0.62); mean net change in diastolic blood pressure was -1.83 mm Hg (95% CI: -3.05 to -0.61); and mean net change in mean arterial pressure was -2.22 mm Hg (95% CI: -4.38 to -0.05). Net reductions in blood pressure were not statistically different between daytime and nighttime. These results indicate that CPAP decreases blood pressure among those with OSA and may help prevent hypertension.     

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。     

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.     

Effect of continuous positive airway pressure therapy on 24-hour blood pressure in patients with obstructive sleep apnea syndrome

BACKGROUND: Patients with obstructive sleep apnea syndrome (OSAS) are subject to an increased cardiovascular morbidity including systemic hypertension. Little is known about the effects of treatment with nasal continuous positive airway pressure (CPAP) on systemic hypertension. METHODS: Automated ambulatory 24-h blood pressure (BP) monitoring was performed in 88 consecutive patients who were referred for evaluation of snoring or suspected OSAS. In addition, the long-term effects of CPAP therapy on 24-h BP were assessed. RESULTS: A total of 62 patients had OSAS and 26 habitual snoring. Patients with OSAS had significantly higher mean arterial BP values than snorers (102.7 +/- 10.7 v 94.0 +/- 10.2 mm Hg; P < .01). Multiple stepwise linear regression analysis disclosed that the degree of systemic hypertension was independently associated with the severity of OSAS as determined by the apnea/hypopnea index (R = 0.43; P < .001), but not with age, body mass index, or smoking habits. Of the 62 patients with OSAS, 52 were treated with CPAP and reevaluated after 9 months. The CPAP resulted in a significant decrease in mean arterial BP (from 103.7 +/- 10.4 to 99.1 +/- 10.8 mm Hg; P < .05). For those patients with systemic hypertension whose BP improved with CPAP therapy, 24-h mean pulse pressure at baseline (r = -0.36; P < .05) as well as average heart rate during the day (r = -0.35; P < .05) turned out as predictors. CONCLUSIONS: Obstructive sleep apnea syndrome contributes, at least in part, to the development of systemic hypertension, and CPAP may improve BP values in treated OSAS patients. Predictors of a beneficial CPAP effect on BP are a high heart rate and a high pulse pressure before treatment.     

Long-term acceptance of continuous positive airway pressure in obstructive sleep apnea

We studied the long-term acceptability of nasal continuous positive airway pressure (CPAP) treatment in 168 consecutive patients, 147 with obstructive sleep apnea (OSA) and 21 with snoring. Follow-up was between 1.5 and 78 months. At latest follow-up 107 of 168 (64%) were still using CPAP. Acceptance of CPAP was least for patients with snoring alone (6 of 21 persisted) and best for patients with both excessive daytime somnolence and severe hypoxemia (minimum SaO2 less than 75%), of whom 40 of 45 (89%) persisted with treatment. Patients with excessive daytime somnolence but without severe hypoxemia were less tolerant of CPAP (39 of 71, 55%, persisted) than patients with no symptoms of excessive somnolence but with severe hypoxemia (21 of 30, 70%, persisted). The most common reasons for discontinuing CPAP were intolerance of the mask (26 of 61), the inconvenience of treatment (16 of 61), and the lack of symptomatic benefit from treatment (10 of 61). We concluded that long-term acceptance of CPAP was difficult to predict in advance but that it was most likely in patients with the most severe sleep apnea. Because intolerance of the mask and inconvenience were the most common reasons for ceasing treatment, improvements in the design of CPAP systems and careful patient training may improve the acceptability of CPAP substantially.     

Autotitration positive airway pressure therapy in patients with obstructive sleep apnea who are intolerant of fixed continuous positive airway pressure

Compliance with continuous positive airway pressure (CPAP) therapy is one of the most difficult management problems for patients with obstructive sleep apnea (OSA). We postulated that autotitration positive airway pressure (APAP) may be effective in some patients who have an intolerance of fixed CPAP. The study was done to estimate how often patients who cannot tolerate fixed CPAP can tolerate APAP. We identified 25 patients seen in the Sleep Disorders Center who had been treated with fixed CPAP for OSA and were intolerant of CPAP therapy despite multiple efforts to improve tolerance. We substituted APAP therapy and measured subjective and objective compliance with treatment 1 month later. The primary end point was the number of patients who successfully tolerated the use of APAP at the end of 30 days, measured objectively by the device's compliance monitor. A positive outcome was defined as an average use of APAP that was greater than 3 h per night on more than 70% of possible nights. Of the 25 patients (mean age, 68 years; mean apnea-hypopnea index, 35), 11 were able to tolerate APAP therapy. The mean number of hours of use in these responders was 6.2; the mean percentage of nights of use among responders was 89%. Determinants of successful APAP use were an apnea-hypopnea index (AHI) less than 18, male sex, OSA related to rapid eye movement, and a high body mass index. APAP therapy may be an effective option in patients who do not tolerate fixed-CPAP therapy.     

Effect of continuous positive airway pressure therapy on infectious complications in patients with obstructive sleep apnea syndrome.

BACKGROUND: Nasal continuous positive airway pressure (CPAP) is a well-established, widely used and effective treatment of obstructive sleep apnea syndrome (OSAS). Unfortunately, side effects are frequent during CPAP treatment. OBJECTIVES: Little is known about the effects of CPAP on infectious complications in patients with OSAS. METHODS: We retrospectively analyzed the kinds and rate of infections of the upper airway in 246 consecutive patients (mean age, 59.7 years) with polysomnographically verified OSAS using CPAP with or without a heated humidifier and compared them with OSAS patients who received non-CPAP therapy. RESULTS: Of the 246 patients, 40 received conservative therapy and 206 CPAP treatment, 36 of them with a heated humidifier. The mean follow-up period of the study group was 165.4 +/- 92.1 weeks and did not differ between the three groups. Infectious diseases were frequent in all three groups, but patients using CPAP without humidifier suffered from upper airway infections significantly more frequently than controls (42.9 vs. 25%; p < 0.05), and more patients on CPAP therapy with humidifier than controls (22.2 vs. 2.5%; p < 0.01) reported an increased rate of upper airway infections since initiation of CPAP therapy or diagnosis of OSAS. Especially patients using a hot water bath humidifier who cleaned their devices inadequately had significantly more upper airway infections since diagnosis (57.1 vs. 20%; p < 0.05) or during the past 6 months (52.4 vs. 13.3%; p < 0.05) than patients who regularly cleaned CPAP machines, humidifiers and ventilatory circuits. CONCLUSIONS: Our results suggest that patients using CPAP therapy either with or without heated humidity seem to be at an increased risk of upper airway infections compared to conservatively treated patients.     

Effect of nasal continuous positive airway pressure in uncontrolled nocturnal asthmatic patients with obstructive sleep apnea syndrome

The mechanisms of nocturnal asthma are intimately related to circadian rhythms, which influence inflammatory cells and mediators, hormone levels and cholinergic tone. Nocturnal airway narrowing in asthma is sometimes associated with sleep disorders, such as obstructive sleep apnea syndrome (OSAS). The aims of this study were to evaluate the association of nocturnal asthma and OSAS, and investigate the influence of continuous positive airway pressure (CPAP) therapy to improve nighttime symptoms in asthmatic patients with OSAS. Forty-three asthmatic patients who had nocturnal symptoms in spite of the optimal medical treatment according to the Global Initiative for Asthma guidelines and associated with snoring were studied. Pulmonary function tests (PFTs), asthma nighttime symptom scores, and polysomnography were performed on all patients. We treated the patients with an apnea-hypopnea index (AHI) 15 (moderate-severe OSAS) (n=16) with CPAP during 2 months. After 2 months, PFT, asthma nighttime symptom scores were reperformed. There was no significant difference in PFT values before and after CPAP treatment in OSAS patients. Asthma nighttime symptom scores were improved significantly (P<0.05) after CPAP treatment. In conclusion, in some patients with nocturnal asthma, OSAS may be responsible disease for nocturnal symptoms. In this condition, CPAP improves nocturnal symptoms without amelioration in PFT abnormalities.     

持续气道正压通气对老年阻塞性睡眠呼吸暂停患者血栓前状态的影响

目的：探讨阻塞性睡眠呼吸暂停综合征(OSAS)老年患者的血栓前状态及经鼻持续气道正压通气(nCPAP)治疗对其影响。方法：选择16例中或重度OSAS老年患者(OSAS组)给予nCPAP治疗，分别于治疗前及治疗30d时的早晨(6：00)及午后(16：00)检测红细胞压积(HCT)、血小板聚集率(PAG)、血液黏滞度(WBV)、血浆纤维蛋白原(Fng)、凝血酶原时间(PT)和部分凝血活酶时间(APTT)。结果：OSAS患者nCPAP治疗前早晨与午后相比，HCT、WBV、血浆Fng及PAG均明显增高，PT及APTT缩短。经nCPAP治疗30d时各项指标在早晨与午后已无明显差异；与治疗前早晨相比，治疗30d早晨的HCT、WBV、PAG、血浆Fng水平均明显降低，且PT及APTT明显延长；与治疗前午后相比，治疗30d时午后的HCT、PAG明显降低，PT及APTT显著延长。结论：OSAS老年患者存在着明显的血栓前状态，nCPAP治疗对其有良好的防治作用。     

Effect of continuous positive airway pressure on soluble CD40 ligand in patients with obstructive sleep apnea syndrome

BACKGROUND: Obstructive sleep apnea syndrome (OSAS) is an independent risk factor for atherosclerosis. CD40-CD40 ligand interaction promotes several proinflammatory mediators and plays a pivotal role in the various stages of atherosclerotic diseases. The present study examines whether CD40 ligation contributes to outcomes in patients with OSAS. METHODS: The study population comprised OSAS patients with an apnea hypopnea index (AHI) > or = 30 (n = 35) and control subjects (AHI < 5; n = 16). We measured serum levels of soluble CD40 ligand (sCD40L), tumor necrosis factor (TNF)-alpha, and hypersensitive C-reactive protein (hsCRP) before and after nasal continuous positive airway pressure (nCPAP) therapy for 3 months. RESULTS: Baseline levels of sCD40L were significantly higher in patients with OSAS (6.93 +/- 4.64 ng/mL) [mean +/- SD] than in control subjects (3.43 +/- 2.11 ng/mL, p < 0.01). Baseline levels of sCD40L positively correlated with TNF-alpha but not with hsCRP. The elevation of sCD40L was improved for 1 night after nCPAP therapy (3.83 +/- 2.78 ng/mL, p < 0.001). Even though patients with severe OSAS did not receive any other medication to control atherosclerotic risk factors for 3 months, nCPAP was continued to reduce the levels of sCD40L. CONCLUSION: The present study suggested that sCD40L is a key factor that links OSAS and atherosclerotic progression.     

Effect of continuous positive airway pressure on homocysteine levels in patients with obstructive sleep apnea: a meta-analysis

Purpose

Continuous positive airway pressure (CPAP) is an effective treatment for obstructive sleep apnea hypopnea syndrome (OSAHS), but previous studies assessing the effect of CPAP on homocysteine (HCY) in patients with OSAHS yielded conflicting results. In this study, we conducted a meta-analysis to determine whether CPAP therapy could reduce plasma HCY levels.

Methods

Searches of PUBMED, SCI, and Elsevier databases were completed. Studies of adult patients with OSAHS who reported HCY levels pre- and post-CPAP treatment were collected by two independent reviewers. RevMan (version 5.2) and STATA (version 12.0) were used to perform data synthesis.

Results

A total of 6 studies involving 206 participants were included. Meta-analysis showed that the total weighted mean difference (WMD) for HCY levels was ?0.62 units (95 % confidence interval (CI) ?1.21 to ?0.04, P?P?>?0.05), but it was significantly reduced after 3 months therapy (WMD, ?1.22, 95 % CI ?2.07 to ?0.38,P?Conclusions This meta-analysis suggests that HCY levels were significantly reduced by CPAP therapy in patients with OSAHS and the HCY levels may be clinically recognized as a valuable indicator for OSAHS treatment, but the clinical significance of this finding as it relates to cardiovascular risk reduction in OSAHS patients warrants further study.