Long-term Continuous Positive Airway Pressure Research Articles

Gender-specific change in leptin concentrations during long-term CPAP therapy

PurposeNasal continuous positive airway pressure (CPAP) alleviates sleepiness in patients with obstructive sleep apnoea syndrome (OSAS), but part of OSAS patients keep gaining weight. Leptin and insulin-like growth factor-1 (IGF-1) interact with energy balance, and CPAP therapy has been suggested to influence these endocrine factors. We hypothesised that leptin would decrease during long-term CPAP therapy, and weight gain would associate with OSAS severity, lower CPAP adherence, lower IGF-1, and leptin concentrations.MethodsConsecutive patients (n = 223) referred to sleep study with suspected OSAS were enrolled. Patients underwent cardiorespiratory polygraphy at baseline. Questionnaires were completed, and blood samples were drawn both at baseline and after 3 years. A total of 149 (67%; M 65, F 84) patients completed the follow-up. Plasma samples were available from 114 patients, 109 of which with CPAP adherence data (49 CPAP users, 60 non-users).ResultsAt baseline, the CPAP users were more obese and had more severe OSAS than the non-users. Leptin concentrations did not differ. After follow-up, leptin concentrations were higher in CPAP users (30.2 ng/ml vs. 16.8 ng/ml; p = 0.001). In regression analysis, increase in leptin concentrations was independent of age, baseline body mass index (BMI), or the change in BMI. Leptin concentrations increased among females (− 8.9 vs. 12.7 ng/ml; p < 0.001); whereas in men, CPAP did not have an effect, if not opposed the natural decrease in leptin observed in men not using CPAP. Change in IGF-1 levels did not differ.ConclusionsOur results suggest increase in leptin concentrations during long-term CPAP therapy among females.

Nonfatal and fatal cardiovascular disease events in CPAP compliant obstructive sleep apnea patients

PurposeObstructive sleep apnea (OSA) is suggested to predispose to cardiovascular disease (CVD) events. It is uncertain whether compliance to continuous positive airway pressure (CPAP) treatment could attenuate the risk. We explored this issue in long-term CPAP users and untreated controls.MethodsRetrospective observational cohort of CPAP-treated and control patients were pairwise matched for gender, age, and apnea–hypopnea index (AHI). The study end point was a composite of nonfatal and fatal CVD events. Cox regression model was used to determine the association between CPAP treatment and event-free survival.ResultsA total of 2060 patients (75.8% male, mean age 56.0 ± 10.5 years), of which 76.4% had moderate–severe OSA, were included. In the CPAP-treated group (N = 1030), the median use of CPAP was 6.4 h/day during a median follow-up of 8.7 years. The control group (N = 1030) was followed for a median of 6.2 years after the CPAP treatment had ended. The study end point occurred in 14.4% (N = 148) of the CPAP-treated and in 18.8% (N = 194) of the control patients (p = 0.006). Using the Cox regression model adjusted for gender, age, AHI, body mass index, and history of CVD, hypertension, type 2 diabetes, and chronic obstructive pulmonary disease at baseline, a beneficial association between CPAP treatment and CVD risk was observed (hazard ratio 0.64, confidence interval 95% 0.5–0.8, p < 0.001).ConclusionsCPAP treatment was associated with a decreased risk of nonfatal and fatal CVD events. Majority of the patients were compliant to CPAP. The association was demonstrated independent from common cardiovascular risk factors and AHI.

Short- and long-term continuous positive airway pressure usage in the post-stroke population with obstructive sleep apnea.

Obstructive sleep apnea (OSA) is highly prevalent in post-stroke patients and observational evidence suggests that untreated it is a harbinger of poorer outcomes in this population. Clinical trials on the impact of treatment of OSA with continuous positive airway pressure (CPAP) have countered difficulties with patient engagement and adherence to CPAP therapy. Real-world data on continuous positive airway pressure initiation and usage in the post-stroke population with obstructive sleep apnea is limited. We performed a clinical retrospective study between January 2006 and June 2015 to describe the short- and long-term CPAP usage in the post-stroke population with OSA, and to assess which patient, disease, and treatment-related factors were associated with CPAP purchase, initiation, and usage in this population. Of 191 post-stroke patients' recommended CPAP therapy, post-prescription usage at 3, 6, 12, 24, and 60months was 58%, 53%, 48%, 45%, and 39% respectively. OSA severity-related factors, such as AHI or degree of nocturnal hypoxemia, were not significantly associated with CPAP usage. Predictors of CPAP usage at all time points were younger age, male sex, never smokers, and no history of hypertension. There were some differences in predictors of CPAP usage between early and later time periods. We demonstrated that the long-term usage of CPAP therapy is possible with most of the attrition occurring in the first 3months. Upfront healthcare resource allocation to CPAP initiation and usage in this population may improve longer-term usage.

Implications of continuous positive airway pressure on heart rate variability in patients with obstructive sleep apnea: Does gender matter?

This study was designed to determine the effectiveness of continuous positive airway pressure (CPAP) treatment on the improvement of heart rate variability (HRV) and whether gender plays a role in HRV in patients with mode-rate to severe obstructive sleep apnea syndrome (OSAS). Consecutive patients with recently diagnosed moderate to severe OSAS underwent continuous synchronized electrocardiographic monitoring and were prospectively considered for inclusion in the study. HRV was analyzed before starting CPAP therapy and 1 year thereafter. The effects of CPAP on HRV were evaluated in men and women separately to ascertain whether there are gender differences in the clinical manifestations of OSAS and whether female HRV responses to CPAP are similar to those of men. A total of 18 patients (10 men, median age: 56 years) were included in the study. There were no significant differences in the baseline clinical characteristics of the male and female patients. After 1 year of CPAP treatment, heart rate decreased (p<0.05) and time domain parameters increased (p<0.05) in both men and women. None of the frequency domain parameters changed in women (p<0.05), whereas the high frequency power measured increased (p<0.05) and the ratio of low frequency to high frequency decreased (p<0.05) in men after 1 year of CPAP treatment. The increase in HRV after 1 year of CPAP therapy was significantly higher in men than in women (p<0.05). CPAP therapy reduced enhanced cardiac sympathetic nerve activity in patients with OSAS assessed according to HRV. The beneficial effect of long-term CPAP therapy on HRV was more pronounced in men.

Long-term Effect of Continuous Positive Air Pressure Therapy on Intraocular Pressure in Patients with Primary Open-angle Glaucoma with Obstructive Sleep Apnea.

ABSTRACTPurposePrevalence of glaucoma is higher in obstructive sleep apnea (OSA) patients. The gold standard technique to treat OSA is continuous positive airway pressure (CPAP) therapy. The influence of long-term CPAP therapy on intraocular pressure (IOP), blood pressure, ocular perfusion pressure (OPP), and glaucoma progression in primary open-angle glaucoma (POAG) patients was evaluated.DesignProspective study.Materials and methodsIn this study, we enrolled 12 eyes from six POAG patients aged >35 years, with newly diagnosed OSA and with indication for CPAP therapy. The CPAP was performed for 12 months. We monitored the IOP every 3 months. Visual field was determined at baseline and 12 months.ResultsThe mean IOP after CPAP therapy for 12 months was significantly higher than the mean baseline IOP (average IOP 3 months before CPAP therapy) (19.08 ± 3.47 vs 17.83 ± 2.88 mm Hg; p = 0.006). The IOP rising rate was 0.69 ± 0.47/years (p = 0.138) before CPAP therapy and increased to 1.13 ± 0.47/years (p = 0.016) after CPAP therapy. The OPP after 12 months of CPAP was significantly lower than the baseline (42.21 ± 5.29 vs 45.24 ± 7.09 mm Hg; p = 0.06). Results showed that the pattern standard deviation (PSD) value of 24-2 short wavelength automated perimetry (SWAP) visual field was reduced from 5.34 ± 3.92 to 4.77 ± 3.73 (p = 0.025). Antiglaucoma medication was administered to a patient due to increased IOP without glaucoma progression evidence.ConclusionThe POAG and OSA patients demonstrated significant IOP rising after CPAP therapy but did not show progression of glaucomatous damage. Mean deviation (MD), PSD, and visual field index (VFI) were not significantly different after CPAP therapy.PrécisProspective study of POAG and OSA patients demonstrated significant IOP rising after CPAP therapy for a year. The study did not show progression of glaucomatous damage.How to cite this articleHirunpatravong P, Kasemsup T, Ayudhya WN, et al. Long-term Effect of Continuous Positive Air Pressure Therapy on Intraocular Pressure in Patients with Primary Open-angle Glaucoma with Obstructive Sleep Apnea. J Curr Glaucoma Pract 2019;13(3):94–98.

Therapeutic effects of long-term continuous positive airway pressure treatment on improving leptomeningeal collateral circulation in obstructive sleep apnea syndrome patients.

This study aims to use methods of scoring collaterals on CT angiography to analyze changes in collateral circulation in untreated patients with moderate and severe OSAS before and after nasal continuous positive airway pressure (CPAP) treatment. Ninety-eight moderate and severe OSAS patients treated with nasal CPAP and seventy-four controls that weren't treated with CPAP, were involved in this study. Two independent neuroradiologists evaluated intracranial collaterals by using Miteff scale, modified Tan scale. Intracranial collaterals differences were compared between OSAS group (before and after treated) and control group. Correlations between intracranial collaterals and clinical parameters were analyzed. Compared with pre-therapy of moderate and severe groups, apnea-hypopnea index (AHI), oxygen desaturation index (ODI), epworth sleepness scale (ESS) were lower after treatment. The lowest oxygen saturation, average blood oxygen saturation, Miterff scale, modified Tan scale in moderate and severe groups were significantly increased after treatment. We documented significant decrease of Miterff scale after two years in moderate and severe OSAS group without CPAP therapy (n = 32, p < 0.01). Conversely, mild OSAS group without CPAP therapy did not change Miterff scale after two years (n = 32, p > 0.05). Multivariate Logistic regression analysis showed that AHI had significant impact on Miterff scale and modified Tan scale. Severe OSAS were independently related with Miterff scale (odds ratio 0.343, 95% confidence interval 0.301-0.391, p < 0.01) and modified Tan scale (odds ratio 0.267, 95% confidence interval 0.095-0.754, p = 0.013). Long-term CPAP treatment is a viable therapeutic choice for improving leptomeningeal collateral circulation in OSAS patients.

Association of Continuous Positive Airway Pressure Treatment With Sexual Quality of Life in Patients With Sleep Apnea

Obstructive sleep apnea reduces sexual quality of life (QOL) as a result of reduced libido and intimacy, erectile dysfunction, and several other mechanisms. Treatment for obstructive sleep apnea may improve sexual QOL. To test the association of long-term continuous positive airway pressure (CPAP) treatment with sexual QOL for patients with obstructive sleep apnea. Prospective cohort study at a single, tertiary medical center of patients with newly diagnosed obstructive sleep apnea who were prescribed CPAP treatment from September 1, 2007, through June 30, 2010 (follow-up completed June 30, 2011). The statistical analysis was performed from February 1 through December 31, 2017. Use of CPAP treatment objectively measured by the number of hours per night. Users of CPAP were defined as patients who used CPAP treatment for more than 4 hours per night, and nonusers were defined as patients who used CPAP treatment for fewer than 0.5 hours per night. Data were collected from eligible patients before CPAP treatment was prescribed and 12 months later by using the validated Symptoms of Nocturnal Obstruction and Related Events-25 (SNORE-25) QOL instrument. The 2 sex-specific items used to create the sexual QOL domain were taken from the SNORE-25. The sexual QOL domain was scored in a range from 0 to 5 (higher score is worse). The difference in sexual QOL between CPAP users and nonusers was analyzed using a paired, 2-tailed t test and multivariable linear regression adjusted for potential confounders. Of the 182 participants in the cohort, 115 (63.2%) were men (mean [SD] age, 47.2 [12.3] years) with severe OSA (mean [SD] apnea-hypopnea index, 32.5 [23.8] events per hour). At the 12-month follow-up, 72 CPAP users (mean [SD] use, 6.4 [1.2] hours per night) had greater improvement than 110 nonusers (0 [0] hours per night) in sexual QOL scores (0.7 [1.2] vs 0.1 [1.1]; difference, 0.54; 95% CI, 0.18-0.90; effect size, 0.47). A moderate treatment association was observed after adjustment for age, sex, race/ethnicity, marital status, income level, educational level, body mass index, apnea-hypopnea index, and the Functional Comorbidity Index (adjusted difference, 0.49; 95% CI, 0.09-0.89; effect size, 0.43). Subgroup analysis revealed a large treatment association for women (adjusted difference, 1.34; 95% CI, 0.50-2.18; effect size, 0.87) but not for men (adjusted difference, 0.16; 95% CI, -0.26 to 0.58; effect size, 0.19). Successful CPAP use may be associated with improved sexual QOL. Subgroup analysis revealed a large improvement in women but no improvement in men. Further study is warranted to test other measures of sexual QOL and other treatments. ClinicalTrials.gov Identifier: NCT00503802.

Home continuous positive airway pressure for cardiopulmonary indications in infants and children

ObjectivesA number of reports exist regarding the use of continuous positive airway pressure (CPAP) to manage obstructive sleep apnoea (OSA) in children, which we term ‘conventional CPAP’. In contrast, there are few reports of home CPAP use for other indications, which we have grouped under the term ‘cardiopulmonary’. The aims of this study were to (1) document cardiopulmonary indications for CPAP use in a cohort of infants and children, and (2) evaluate its effectiveness in this group. MethodsHospital records were reviewed for 645 patients who were commenced on long-term CPAP over a 10-year period at a single-tertiary hospital (Children's Hospital at Westmead). This study evaluated the group where the primary indication for CPAP was not OSA (‘cardiopulmonary CPAP’). Data evaluated included: demographics, diagnoses, indications for CPAP, hours of use (compliance) and sleep study results at baseline and on CPAP. ResultsOf 645 children, 148 (23%) used home CPAP for cardiopulmonary indications; and 130 (87.8%) of these were included. For this group, mean age at CPAP initiation was 18.6 ± 33.6 months (range one week to 16.8 years). Cardiopulmonary indications for CPAP use included: primary airway diseases 65 (50%), chronic lung diseases 33 (25.4%), congenital heart disease (CHD) 20 (15.4%), and both CHD and airway malacia 12 (9.2%). All sleep study variables improved on CPAP relative to the diagnostic sleep study (p < 0.0001), including reduced respiratory rate with CPAP use (p < 0.0001). CPAP was well tolerated (>4 h/night). ConclusionsInterstitial lung diseases and other cardiorespiratory disorders, often of congenital origin, can be effectively treated with home CPAP whether they are associated with OSA or not. Sleep studies demonstrated improved gas exchange, sleep and reduced work of breathing with CPAP use.

CPAP therapy improves erectile function in patients with severe obstructive sleep apnea

ObjectivesErectile dysfunction (ED) is highly prevalent in obstructive sleep apnea (OSA), however, the effect of continuous positive airway pressure (CPAP) therapy on erectile function has not yet been thoroughly investigated in these patients. MethodsNinety-four men with severe OSA (ie, with an apnea-hypopnea-index ≥ 30/h of sleep) were prospectively evaluated for the presence and severity of ED before and after 6–12 months of CPAP therapy. The abbreviated version of the International Index of Erectile Function, (the IIEF-5) was used to rate erectile function. Furthermore, all study participants responded to standard questionnaires of daytime sleepiness (Epworth Sleepiness Scale), quality of life (WHO Wellbeing 5 questionnaire) and depression (Major Depression Inventory). ResultsED as defined by an IIEF-5 score of ≤21 was present in 64 patients (68.1%). CPAP treatment significantly improved erectile function in those patients suffering from moderate and severe ED. Additionally, a trend for a correlation between the improvement of erectile function under CPAP and the hours of its use was observed. Finally, this effect was associated with larger improvements of quality of life in affected patients. ConclusionsED is very frequent in men with severe OSA and can at least partly be reversed by long-term CPAP therapy in most seriously affected patients. The beneficial effect on erectile function may depend on CPAP compliance and is accompanied by improvements of quality of life. Randomized controlled trials are needed to confirm these findings.

Effects of 12 months of continuous positive airway pressure therapy on cognitive function, sleep, mood, and health-related quality of life in a peritoneal dialysis patient with obstructive sleep apnea

This report describes the case of a hypertensive 51-year-old male with a 3-year history of peritoneal dialysis. We followed the patient through his diagnosis of severe obstructive sleep apnea (OSA) and treatment with continuous positive airway pressure (CPAP). Therapeutic use of CPAP led to the improvement of not only sleep-related problems, but also cognitive function and quality of life. To our knowledge, this is the first paper describing the benefits of long-term CPAP treatment in an OSA patient undergoing dialysis. This case report emphasizes the need for the proactive diagnosis and treatment of OSA in end-stage renal disease patients to improve patient-centered healthcare.

Abstract TMP45: An Intensive Multidisciplinary Protocol for Improving Adherence to CPAP Therapy During Inpatient Rehabilitation May Improve Recovery in Stroke Patients

Introduction: Obstructive sleep apnea (OSA) is associated with worse outcome after stroke. Treatment with continuous positive airway pressure (CPAP) may improve recovery after stroke but has been limited by poor adherence. Methods: In a single-arm ongoing study, adults with stroke underwent an intensive CPAP adherence protocol during inpatient rehabilitation, including motivational interviewing and help with CPAP by nurses and respiratory therapists. A 3-night run-in period of auto-titrating CPAP was used to test for tolerance and to diagnose OSA, based upon the apnea-hypopnea index and flow resistance. Qualifying patients were asked to continue CPAP for 3 months. The outcomes included CPAP adherence, defined as ≥ 4 hours of use on ≥ 70% of nights, and stroke recovery, measured by change in NIH Stroke scale (NIHSS) and Functional Independence Measure (FIM) over 3 months. Results: During the run-in, 39 of 60 (65%) patients had presumed OSA, 5 (8%) had no evidence of OSA, 4 (7%) had evidence of central sleep apnea, and 12 (20%) were intolerant of CPAP. Among the 34 of 39 patients who chose to continue CPAP after the run-in, the median use per night was 5.3 hours (IQR 4.1, 6.0) with 56% (n=19) adherent during rehabilitation. The median CPAP use per night for the 22 who completed the study was 5.1 hours (IQR 2.5, 6.4) with 54% (n=12) adherent over the 3-month period. Unadjusted for baseline factors, there was a significant change in the NIHSS in adherent patients (n=10) vs. non-adherent patients (n=10) [5 (SD 3) vs. 2 (SD 2), p =0.02]. Comparing adherent (n=7) to non-adherent patients (n=5), the change for total FIM trended towards significant [42 (SD 18) vs. 30 (SD 11), p =0.20] and the change for cognitive component of the FIM was significant [10 (SD 7) vs. 2 (SD 3), p =0.05]. Conclusion: After an intensive adherence intervention, over half of stroke patients with presumed OSA and CPAP tolerance were adherent over 3 months. CPAP adherent patients had greater improvement in NIHSS and the cognitive component of the FIM, although the associations may be confounded by patients’ characteristics influencing both adherence and outcomes. Future studies are needed to evaluate in a randomized trial if the intensive intervention will lead to long-term CPAP adherence and improved stroke recovery.

Long-term use of continuous positive airway pressure therapy in coronary artery disease patients with nonsleepy obstructive sleep apnea.

Excessive daytime sleepiness is a frequent symptom of obstructive sleep apnea (OSA) and has been proposed as a motivator for adherence to continuous positive airway pressure (CPAP) therapy. However, excessive daytime sleepiness is absent in many patients with coronary artery disease (CAD) and concomitant OSA. We evaluated long-term use of CPAP and predictors of CPAP use in nonsleepy and sleepy OSA patients from a CAD cohort. Long-term CPAP use is lower in CAD patients with nonsleepy OSA vs sleepy OSA. Nonsleepy (Epworth Sleepiness Scale [ESS] score < 10) OSA patients randomized to CPAP (n = 122) and sleepy (ESS ≥10) OSA patients offered CPAP (n = 155) in the RICCADSA trial in Sweden were included in this substudy. The median follow-up was 4.8 years for the main trial, with a predefined minimum follow-up of 2 years. The probability of remaining on CPAP at 2 years was 60% in nonsleepy patients and 77% in sleepy patients. Multivariate analyses indicated that age and hours of CPAP use per night at 1 month were independently associated with long-term CPAP use in nonsleepy patients. In the sleepy phenotype, body mass index, acute myocardial infarction at baseline, and hours of CPAP use per night at 1 month were predictors of long-term CPAP use. Long-term use of CPAP is likely to be challenging for CAD patients with nonsleepy OSA. Early CPAP use is an important predictor of continued long-term use of CPAP, so optimizing patients' initial experience with CPAP could promote adherence.

Impact of long-term continuous positive airway pressure on liver fat in male obstructive sleep apnea patients with fatty liver

Obstructive sleep apnea (OSA) is an established factor in the pathogenesis and exacerbation of fatty liver disease. However, randomized controlled trials have failed to demonstrate decreases in liver fat content in OSA patients by continuous positive airway pressure (CPAP) performed for several months. The aim of this study is to investigate the impact of long-term CPAP therapy on liver fat content in OSA patients with fatty liver. Liver fat content in 61 male OSA patients was evaluated by computed tomography performed because of abdominal obesity before and after CPAP initiation. At baseline, there were 25 participants with fatty liver. Their apnea–hypopnea index and percent sleep time with oxygen saturation < 90% were greater than those in the 36 participants who did not have fatty liver (52.3 vs. 41.8/h and 30.4 vs. 14.8%, respectively). The average therapy duration was 31 months. In the analysis of the entire participant group, liver fat content did not change after CPAP therapy. In those without fatty liver, liver fat content increased accompanied by increases in BMI, whereas in the participants with fatty liver, liver fat content decreased despite stable BMI, abdominal fat distribution, and insulin resistance. In male OSA patients with abdominal obesity, decreases in liver fat content were observed after long-term CPAP therapy only when fatty liver was present at baseline. This implies that there are some conditions, such as OSA-related hypoxemia and others, which may exacerbate fatty liver and that fatty liver may improve with CPAP therapy.

Pneumoparotitis as a complication of long-term oronasal positive airway pressure for sleep apnea.

Parotid swelling is rarely caused by pneumoparotitis from retrograde insufflation of air into Stensen's duct. Previous reports have identified occupational exposures, self-induced habits, exercise, spirometry, and short-term positive pressure airway ventilation as causes of salivary duct insufflation. We present 2 cases of pneumoparotitis in patients on long-term oronasal continuous positive airway pressure (CPAP) for obstructive sleep apnea. A diagnosis of pneumoparotitis was made by CT scan in case 1 and sialography in case 2. Patients were advised to transition from oronasal to nasal-only CPAP. One patient was successfully transferred and had good symptomatic improvement, whereas the second patient did not tolerate nasal CPAP and had persistent symptoms on oronasal CPAP. Long-term use of oronasal CPAP is a potential cause of pneumoparotitis.

Telemonitoring in continuous positive airway pressure-treated patients improves delay to first intervention and early compliance: a randomized trial

ObjectiveTelemonitoring (TM) has been used in continuous positive airway pressure (CPAP)−treated patients to improve compliance, but results have been inconsistent. The purpose of this study was to assess the impact of TM on the delay to the first technical intervention after CPAP initiation. The impact of TM on mean compliance during the first 3 months of treatment was measured as a secondary outcome. MethodsPatients diagnosed with moderate to severe obstructive sleep apnea syndrome were prospectively included and randomized to receive usual care (UC) or TM. In both arms, an educational session was scheduled 1 month after CPAP initiation, and medical visits were planned after 1.5 and 3 months. In the TM arm, we added a universal TM unit (T4P) to the CPAP device. ResultsDelay to first intervention was significantly shorter in the TM group (29 ± 25 vs 47 ± 30 days, p = 0.02). The first intervention in the TM group was motivated by detection of problems by the TM system in 39% of patients. Compliance at 3 months was significantly better in the TM group (5.7 ± 1.6 vs 4.2 ± 1.9 h/night, p = 0.018). ConclusionThis is the first randomized study showing that TM reduces delay to first technical intervention in CPAP-treated patients. This early activation of troubleshooting was associated with improved compliance at 3 months. Since CPAP side effects at 1 month have been shown to predict lower 12-month CPAP compliance, TM seems to be an excellent tool for improvement of long-term CPAP acceptance.

Genome-wide gene expression array identifies novel genes related to disease severity and excessive daytime sleepiness in patients with obstructive sleep apnea.

We aimed to identify novel molecular associations between chronic intermittent hypoxia with re-oxygenation and adverse consequences in obstructive sleep apnea (OSA). We analyzed gene expression profiles of peripheral blood mononuclear cells from 48 patients with sleep-disordered breathing stratified into four groups: primary snoring (PS), moderate to severe OSA (MSO), very severe OSA (VSO), and very severe OSA patients on long-term continuous positive airway pressure treatment (VSOC). Comparisons of the microarray gene expression data identified eight genes up-regulated with OSA and down-regulated with CPAP treatment, and five genes down-regulated with OSA and up-regulated with CPAP treatment. Protein expression levels of two genes related to endothelial tight junction (AMOT P130, and PLEKHH3), and three genes related to anti-or pro-apoptosis (BIRC3, ADAR1 P150, and LGALS3) were all increased in the VSO group, while AMOT P130 was further increased, and PLEKHH3, BIRC3, and ADAR1 P150 were all decreased in the VSOC group. Subgroup analyses revealed that AMOT P130 protein expression was increased in OSA patients with excessive daytime sleepiness, BIRC3 protein expression was decreased in OSA patients with hypertension, and LGALS3 protein expression was increased in OSA patients with chronic kidney disease. In vitro short-term intermittent hypoxia with re-oxygenation experiment showed immediate over-expression of ADAR1 P150. In conclusion, we identified a novel association between AMOT/PLEKHH3/BIRC3/ADAR1/LGALS3 over-expressions and high severity index in OSA patients. AMOT and GALIG may constitute an important determinant for the development of hypersomnia and kidney injury, respectively, while BIRC3 may play a protective role in the development of hypertension.

Diagnosing and managing sleep apnea in patients with chronic cerebrovascular disease: a randomized trial of a home-based strategy

BackgroundObstructive sleep apnea is common and associated with poor outcomes after stroke or transient ischemic attack (TIA). We sought to determine whether the intervention strategy improved sleep apnea detection, obstructive sleep apnea (OSA) treatment, and hypertension control among patients with chronic cerebrovascular disease and hypertension.MethodsIn this randomized controlled strategy trial intervention, patients received unattended polysomnography at baseline, and patients with OSA (apnea-hypopnea index ≥5 events/h) received auto-titrating continuous positive airway pressure (CPAP) for up to 1 year. Control patients received usual care and unattended polysomnography at the end of the study, to identify undiagnosed OSA. Both groups received 24-h blood pressure assessments at baseline and end of the study. “Excellent” CPAP adherence was defined as cumulative use of ≥4 h/night for ≥70% of the nights.ResultsAmong 225 randomized patients (115 control; 110 intervention), 61.9% (120/194) had sleep apnea. The strategy successfully diagnosed sleep apnea with 97.1% (102/105) valid studies; 90.6% (48/53, 95% CI 82.7–98.4%) of sleep apnea was undiagnosed among control patients. The intervention improved long-term excellent CPAP use: 38.6% (22/57) intervention versus 0% (0/2) control (p < 0.0001). The intervention did not improve hypertension control in this population with well-controlled baseline blood pressure: intervention, 132.7 mmHg (±standard deviation, 14.1) versus control, 133.8 mmHg (±14.0) (adjusted difference, −1.1 mmHg, 95% CI (−4.2, 2.0)), p = 0.48).ConclusionsPatients with cerebrovascular disease and hypertension have a high prevalence of OSA. The use of portable polysomnography, and auto-titrating CPAP in the patients’ homes, improved both the diagnosis and the treatment for sleep apnea compared with usual care but did not lower blood pressure.

Impact of Continuous Positive Airway Pressure on Left Ventricular Systolic Loading and Coronary Flow Reserve in Healthy Young Men

Increased augmentation index (AIx) is accompanied by an elevated cardiovascular risk. A reduction of AIx is known for long-term continuous positive airway pressure (CPAP) therapy. We hypothesised that acute preload and left ventricular workload effects AIx and subendocardial viability ratio (SEVR) as a marker of coronary flow reserve. Increased augmentation index and central blood pressure parameters were measured by radial artery tonometry in 17 healthy men (32/±6years) at rest and during CPAP ventilation at pressures of 5, 10mbar and after recovery. In a subset of seven individuals, haemodynamic parameters and autonomic function were additionally examined using combined impedance cardiography and continuous noninvasive blood pressure monitoring. Continuous positive airway pressure reduced heart rate corrected (AIx@75) (-2.8±8.1 [rest] to -10.7±11.3 [5mbar], p<0.01, to -12.2±10.5% [10mbar], p<0.01) and systolic time integral as a marker of left ventricular workload (2115±231 [rest] to 1978±290 [5mbar], p=0.02 to 1940±218 [10mbar], p<0.01 to 2013±241mmHg/s per min [recovery], p=0.03), while central systolic pressure did not change during CPAP. Total Peripheral Resistance Index increased reaching level of significance at 10mbar CPAP condition (1701±300 [rest] to 1850±301dyn*s*m2/cm5 [10mbar], p=0.04). There was a reversible increase of SEVR under CPAP conditions. Continuous positive airway pressure ventilation acutely reduces AIx, heart rate and left ventricular workload in healthy young men. These effects seem to be mediated by left ventricular filling pressure, workload and reflection wave. Furthermore, we found an increase of subendocardial viability ratio as an indication for a rising coronary flow reserve by CPAP.

Measurement of exhaled nitric oxide concentration in patients with obstructive sleep apnea: A meta-analysis.

Exhaled nitric oxide (eNO) has been proposed as a noninvasive measure of airway inflammation. However, its value in patients with obstructive sleep apnea (OSA) is still controversial. The authors aim to assess the difference in eNO levels between patients with OSA and controls by a meta-analysis. A systematic search was performed in the PubMed, EMBASE, the Cochrane Library, and MEDLINE databases to collect relevant studies published from 1996 to 2016. Eligible studies that reported eNO levels in patients with OSA were included. STATA (version 12.0) was used for data analysis. Two hundred eighty-four studies were reviewed for inclusion, with 16 studies pooled for analysis (16 studies for fractional exhaled nitric oxide [FENO], 5 for alveolar nitric oxide [CANO], and 4 for the maximum airway wall flux of nitric oxide [J'awNO]). The FENO levels were significantly higher in patients with OSA compared with that in the control groups (6.32 ppb, 95% confidence interval [CI] 4.46-8.33, P < 0.001). Furthermore, FENO was significantly increased (4.00 ppb, 95% CI 1.74-6.27, P = 0.001) after overnight sleep in patients with OSA, but not in healthy controls. Additionally, long-term continuous positive airway pressure (CPAP) therapy reduced FENO levels (-5.82 ppb, 95% CI -9.6 to -2.01, P < 0.001). However, the CANO (-0.01 ppb, 95% CI -1.66 to 1.64, P = 0.989) and J'awNO levels (220.32 pl/s, 95% CI -49.31 to 489.94, P = 0.109) were not significantly different between the OSA groups and non-OSA groups. The results of the meta-analysis suggest that OSA is significantly associated with airway inflammation and elevated FENO levels can be modified by long-term CPAP therapy. J'awNO and CANO levels were not significantly different between the OSA groups and control groups.

The effect of continuous positive airway pressure treatment on P-wave dispersion and intrinsicoid deflection time in severe obstructive sleep apnea syndrome

OBJECTIVE: This study aims to evaluate the effects of continuous positive airway pressure (CPAP) treatment on intrinsicoid deflection time (R wave peak time) and P wave discrimination in severe obstructive sleep apnea syndrome (OSAS). METHODS: Fifty-five patients with severe OSAS (apnea-hypopnea index ≥ 30) and a healthy control group were included. Baseline electrocardiography (ECG), echocardiography (ECHO), and polysomnography parameters were recorded. All patients received CPAP treatment. ECG and ECHO echocardiography tests were repeated after one-year of CPAP therapy. RESULTS: A total of 55 OSAS patients (36 M, 19 F) with a mean age of 56.9 ± 7.6 years and 54 healthy controls (31 M, 23 F) with a mean age of 56.6 ± 5.7 years were included. There was a significant improvement in terms of intrinsicoid deflection time in lead V1 (76.2 ± 8.3 vs. 59.8 ± 7.2) and lead V6 (58.5 ± 8.0 vs. 49.8 ± 7.1), and P-wave dispersion (95.2 ± 12.8 vs. 39.8 ± 6.4) after one-year CPAP treatment (p<0.001). Cardiac volumes and diameters improved significantly. CONCLUSION: CPAP treatment significantly decreases intrinsicoid deflection time in leads V1 and V6, and improves P-wave dispersion. The results of this study indicate that long-term CPAP treatment had a strong protective effect on right or left cardiac functions in severe OSAS patients without any cardiac and pulmonary disease.