Severe Obstructive Sleep Apnea Group Research Articles

Association of the serum irisin level with obstructive sleep apnea: a body mass index- and physical activity-matched study.

Obesity is strongly correlated with the pathogenesis of obstructive sleep apnea (OSA); myokines may play important roles in this condition. We performed a body mass index- (BMI) and physical activity- (PA) matched study to explore the relationship between the irisin level and OSA. Ninety-six consecutive participants were recruited. After matching in terms of BMI and PA, 28 OSA patients and 28 healthy controls were finally included. Whole-night laboratory-based polysomnography was used to identify OSA. The Recent Physical Activity Questionnaire and Epworth Sleepiness Scale Questionnaire were employed to assess PA over the past 4 weeks, and daytime sleepiness. We measured serum irisin, fasting blood glucose, and insulin levels in blood samples. The serum irisin concentrations differed significantly between the control, mild OSA, moderate OSA, and severe OSA groups (p < 0.001) and correlated significantly with the apnea/hypopnea index (AHI) (r = -0.787, p < 0.001). All of age, BMI, neck, waist and hip circumferences, fasting blood glucose level, and the Epworth Sleepiness Scale and PA scores were associated with irisin levels (p < 0.05). After adjustment for these factors, the serum irisin level was independently correlated with the AHI (r = -0.428, p = 0.002). On forward logistic regression analysis, the association remained significant in the final multiple regression model (β = -0.107, p < 0.001). The serum irisin concentration was significantly correlated with OSA severity, independently of BMI and PA. Further studies are needed to determine the molecular mechanisms in play.

Is there any relationship between the time spent in respiratory events and cardiovascular morbidity in obstructive sleep apnea patients?

Aim: The importance of the duration of respiratory events, in addition to the number, in the evaluation of obstructive sleep apnea (OSA) is gradually increasing. We aimed to investigate whether parameter including the number and duration of respiratory events predict cardiovascular mortality. Material and Methods: A retrospective study included 200 patients with OSA (100 severe, 50 moderate, 50 mild). Time spent during respiratory events, including the number and duration of respiratory events, was calculated for each respiratory event. Obstructive apnea time (OAT), hypopnea time (HT), total apnea time (TAT), and total respiratory event time (TRET) were obtained. The relationship between cardiovascular diseases of the patients and the time spent during respiratory events was examined. Results: There was no relationship between the cardiovascular diseases and the time spent during respiratory events in the mild, moderate and all OSA group; however, the prolonged OAT (p=0.024) and TAT (p=0.039) in the severe OSA group were associated with an increase in the cardiovascular diseases, independent of other variables. However, the relationship between apnea-hypopnea index (AHI) and cardiovascular diseases in mild, moderate, severe, and all OSA was not significant.Conclusion: Using parameters including the duration of respiratory events in addition to AHI may be more useful to understand the comorbidities of OSA particularly cardiovascular diseases.

Assessment of the relationship between endocan and obstructive sleep apnea severity.

IntroductionObstructive sleep apnea (OSA) and endothelial dysfunction are associated with cardiovascular risk factors and the development of atherosclerosis. Endocan is a marker of endothelial dysfunction, while obstructive sleep apnea is one of the causes of endothelial dysfunction. In this study, we investigated the relationship between endocan and obstructive sleep apnea severity.Material and methodsA total of 179 patients with snoring complaints were included. All patients underwent polysomnography, and based on the results, the participations were allocated to the control group (n = 39) or to the obstructive sleep apnea group (n = 140). The OSA group was classified as having mild (apnea-hypopnea index (AHI) = 5–15; n = 43), moderate (AHI = 15–30; n = 42), or severe OSA (AHI > 30; n = 55). All participations had their endocan levels measured.ResultsEndocan levels in OSA patients were significantly higher than in the control group (11.8 (3.13–200) vs 3.13 (3.13–23) ng/ml, p < 0.001). Also, endocan levels were significantly higher in the severe OSA group than moderate and mild obstructive OSA (13.2 (3.13–200), 12.6 (3.13–200) and 8.44 (3.13–50.5) ng/ml, p = 0.015, respectively). Multiple logistic regression analysis showed that smoking, age and endocan levels were independent predictors of OSA severity (p = 0.024, p = 0.037, p = 0.004, respectively).ConclusionsEndocan seems to be a potential risk stratification marker in this patient population.

Validation of NoSAS Score and Obstructive Sleep Apnea Hypopnea Syndrome Screening Model for Female Snorers in Females with Obstructive Sleep Apnea

Objective To evaluate the NoSAS score and the obstructive sleep apnea hypopnea syndrome(OSAHS)screening model for female snorers with obstructive sleep apnea(OSA)in females and compare the performance of these two tools. Methods A total of 425 females with suspected OSA who underwent overnight polysomnography(PSG)were consecutively recruited into this study.The above two questionnaires were completed.Based on the severity of OSA which was determined by apnea-hypopnea index(AHI),the patients were classified into four groups:non-OSA group(AHI<5 events/h),OSA group(AHI≥5 events/h),moderate-to-severe OSA group(AHI>15 events/h),and severe OSA group(AHI>30 events/h).The sensitivity,specificity,positive predictive values,negative predictive values,and the area under the receiver operating characteristics(ROC)curve of two questionnaires were calculated. Results The sensitivity of NoSAS score for OSA,moderate-to-severe OSA,and severe OSA groups were 57.3%,64.9%,and 69.5%,and its specificity was 83.5%,76.6%,and 70.9%,respectively.The sensitivity of the OSAHS screening model of female snorers was 62.7%,74.8%,and 75.8%,and its specificity was 92.5%,84.3%,and 74.5%,respectively.Both of these two screening tools had high specificity and performed well in ruling out non-OSA females.For patients with their AHI≥5 events/h,the results of NoSAS score and OSAHS screening model were in moderate to high consistency with those diagnosed by PSG,with a Kappa value of 0.401 and 0.541,respectively.The area under curve of these two tools was 0.792(95% CI=0.750-0.829)and 0.866(95% CI=0.830-0.897),respectively,showing moderate screening value.The area under curve of the OSAHS screening model of female snorers was significantly larger than that of NoSAS score(P =0.002,P =0.003,P =0.019). Conclusions Both the NoSAS score and the OSAHS screening model for female snorers have a moderate performance in diagnosing OSA in females,although the OSAHS screening model for female snorers has better performance.However,the sensitivity of the OSAHS screening model needs to be further improved.

High-resolution Peripheral Quantitative Computed Tomography for the Assessment of Bone Strength and Structure in Obstructive Sleep Apnea Patients

Objective To evaluate the bone strength and structure of patients with obstructive sleep apnea(OSA)by the high-resolution peripheral quantitative computed tomography(HR-pQCT)and to explore the relationship between OSA and osteoporosis. Methods Male patients who visited the Sleep Respiratory Center of our hospital from August 2017 to January 2019 were consecutively recruited.Clinical data including the results of Epworth sleep scale(ESS)scoring and overnight polysomnography were collected.HR-pQCT was used to compare the differences in bone geometry,density,and microstructure between OSA patients and non-OSA people;also,the radius and tibia on the non-dominant side were measured to explore the relationship between OSA and osteoporosis. Results A total of 83 subjects were enrolled in the study.The number of patients in the mild,moderate,and severe OSA groups and non-OSA group were 21,18,34,and 10,respectively.There was no significant difference in age,blood pressure,ESS score,sleep stage,and sleep efficiency among these four groups(P>0.05).Body mass index(BMI)and neck circumference were significantly different among these groups(F=4.234,P=0.008;F=3.100,P=0.031).There was no significant difference in the radius indicators(P>0.05).For tibia,there were significant differences among the four groups in the cortical area(Ct.Ar)(F=3.937,P=0.011).There were also significant differences in the bone microstructural indicators including trabecular thickness(Tb.Th)and cortical thickness(Ct.Th)(F=6.247,P=0.001;F=3.746,P=0.014),which were significantly lower in the three OSA groups than in the control group.Pairwise comparisons showed that the Ct.Ar in the severe OSA group was significantly higher than that in the mild OSA group(P=0.019)and Tb.Th in the control group was significantly higher than those in the mild and moderate OSA groups(P=0.006,P=0.001).Correlation analysis showed that,within a certain range,total volumetric bone mineral density(Tt.vBMD)and Tb.Th of radius and tibia were negatively correlated with age(r=-0.312,P=0.004;r=-0.328,P=0.002;r=-0.265,P=0.015;r=-0.280,P=0.010)and positively correlated with BMI(r=0.240,P=0.029;r=0.369,P=0.004;r=0.299,P=0.006;r=0.416,P=0.010).Stepwise multiple regression analysis showed that Tb.Th of radius and tibia were mostly correlated with BMI(β=0.262,P=0.008,R 2=0.243,F=6.270,P=0.000;β=0.494,P=0.000,R 2=0.186,F=7.243,P=0.000)and age(β=-0.216,P=0.030,R 2=0.243,F=6.270,P=0.000;β=-0.306,P=0.003,R 2=0.186,F=7.243,P=0.000).Tt.vBMD of radius had a certain correlation with sleep efficiency and with the decreasing nocturnal mean oxygen saturation caused by OSA(β=0.312,P=0.002, β=-0.249,P=0.012,R 2=0.327,F=7.482,P=0.000). Conclusions In non-elderly male populations,OSA mainly causes a decrease in Tb.Th and Ct.Th of the tibia.The changes in bone strength and structure are mainly related with age and body size and also have certain correlations with sleep efficiency and with the decreasing nocturnal mean oxygen saturation caused by OSA.

Significance of sleep stability using cardiopulmonary coupling in sleep disordered breathing

The aim of this study was to assess the sleep quality and sleep stability according to the severity of obstructive sleep apnea (OSA) by using questionnaires and cardiopulmonary coupling (CPC) analysis. Two hundred and twenty-one adults were evaluated using subjective sleep questionnaires, CPC parameters, and respiratory parameters measured during full-night polysomnography. We measured the differences in the CPC parameters of each OSA group and the correlation between the apnea-hypopnea index (AHI) and CPC parameters. AHI and CPC parameters were not associated with sleep questionnaires. AHI is negatively correlated with high frequency coupling (HFC, r = -0.725, P < 0.001) and very low frequency coupling (VLFC, r = -0.475, P < 0.001), but it is positively correlated with low frequency coupling (LFC, r = 0.786, P < 0.001) and narrow- and broadband-elevated low frequency coupling (e-LFCNB and e-LFCBB ; r = 0.522, P < 0.001 and r = 0.668, P < 0.001, respectively). We also found similar results regarding the correlation between the arousal index and CPC parameters. In addition, there were significant differences in HFC, LFC, VLFC, e-LFCNB , and e-LFCBB (all P < 0.001) between the severe OSA group and all other groups. We found that CPC parameters significantly correlated with AHI. In addition, sleep stability-related parameters differ significantly based on OSA severity, and apneic parameters in the severe OSA group are significantly different from those in the other groups. 4 Laryngoscope, 130: 2069-2075, 2020.

Oropharyngeal Microbiome in Obstructive Sleep Apnea: Decreased Diversity and Abundance.

To explore and analyze diversity and abundance of oropharyngeal microbiota in patients with obstructive sleep apnea (OSA). This was a cross-sectional study. Middle-aged men, suspected to have OSA, referred to full-night polysomnography, and willing to provide oropharyngeal swab samples, were consecutively enrolled. OSA severity was assessed by apnea-hypopnea index (AHI) as non-OSA (AHI < 5 events/h) and OSA (AHI ≥ 15 events/h). Bacterial DNA of oropharyngeal samples was extracted and quality test performed. Oropharyngeal microbiota was analyzed using 16S ribosomal DNA (rDNA) sequencing, and bioinformatic analysis carried out after sequencing. Samples from 51 men (25 in the non-OSA group and 26 in the OSA group) were sent for examination. Of these, 40 samples were found to have sufficient concentration of DNA and were analyzed for bioinformatics. In alpha diversity analysis, the OSA group exhibited significantly lower sobs (198.33 ± 21.71 versus 216.57 ± 26.21, P = .022), chao (221.30 ± 26.62 versus 243.86 ± 26.20, P = .014), ace (222.17 ± 27.15 versus 242.42 ± 25.81, P = .028) and shannon index (3.14 ± 0.23 versus 3.31 ± 0.26, P = .035), suggesting a reduction in microbial species diversity. We further divided participants into non-OSA, moderate OSA, and severe OSA groups and observed a significant decrease in the bacterial biodiversity of OSA groups compared with the non-OSA group, with the most significant decrease occurring in the moderate OSA group. Principal coordinate analysis showed two extremely different oropharyngeal microbial communities in non-OSA and OSA groups. More interestingly, proportion of Neisseria was slightly higher in the severe OSA group (20.64%), followed by the moderate OSA and non-OSA groups (12.57% and 9.69%, respectively). Glaciecola was not detected in the OSA groups compared to the non-OSA group (0 versus 0.772 ± 0.4754, P < .001). Middle-aged men with OSA showed less oropharyngeal species diversity and altered abundance, on which further confirmation is warranted.

The correlation studies between ambulatory blood pressure and OSA in non-hypertensive patients

Objective:To discuss the changes and rules of nighttime blood pressure in obstructive sleep apnea(OSA) patients without hypertension.Method:Eighty-nine non-hypertensive patients whose office blood pressure was lower than 130/85 mmHg and diagnose with OSA by PSG in sleep monitoring room were choose as the research group.Forty non-hypertensive and polyp of vocal cord or vocal nodules patients whose office blood pressure was lower than 130/85 mmHg and diagnose with non-OSA by PSG were choose as matched group.All the patients were in treatment in our hospital from December 2017 to June 2018. All the patients got PSG,and the same time got the ambulatory blood pressure monitoring based on pulse transit time all night.Compared the mean value of systolic blood pressure,the mean value of diastolic blood pressure.Higher than 12 mmHg blood pressure rise index,the mean rise in blood pressure. The highest increase in blood pressure, maximum systolic pressure between the study group and the marched group all night.Result:The difference of all the test index between the study group and the marched group was significant(P<0.05).In OSA patients.The difference of all the test index between the severe OSA group and the mild OSA group or the moderate OSA group was significant(P<0.05).In severe OSA group.The difference between the fluctuation of blood pressure caused by respiratory events and spontaneous blood pressure fluctuation was significant(P=0.004).The difference of the mean value of diastolic blood pressure(P=0.032) blood pressure rise index(P=0.037) the mean rise in blood pressure(P=0.045) between age 55 or older patients and under 55years old patients.Conclusion:Ambulatory blood pressure monitoring synchronizatied in PSG contribute to the early diagnosis and prevention of hypertension in OSA patients.

Effect of moderate or severe obstructive sleep apnea on cardiac structure and function in patients with acute coronary syndrome

Objective: To investigate the effect of obstructive sleep apnea (OSA) on cardiac structure and function in patients with acute coronary syndrome (ACS). Methods: A total of 767 patients with ACS consecutively hospitalized at the Emergency & Critical Care Center of Beijing Anzhen Hospital from June 2015 to May 2017 were enrolled in this study. There were 637 males and 130 females. Patients who met the inclusion criteria according to the sleep apnea hypopnea index (AHI) were examined with portable sleep respiration monitoring. Patients were divided into moderate or severe OSA group (AHI≥15,n=389) and non or mild OSA group (AHI<15, n=78). The general information and echocar diographic results were analyzed. The data fitted normal distribution were compared between the groups with independent sample t test. Results: The body mass index [(27.8±3.6) vs (25.8±3.4) kg/m(2), t=-7.854, P<0.01], neck circumference [(41.1±4.2) vs (39.3±3.2) cm, t=-6.717, P<0.01] and waist-to-hip ratio (0.99±0.54 vs 0.97±0.53, t=-4.735, P<0.01) at admission were significantly higher in moderate or severe OSA group than those in non or mild OSA group. The left ventricular end-diastolic diameter, inter-ventricular septum thickness, left atrial diameter,right atrial diameter were all significantly higher, and the E/A peak ratio was remarkably lower in the moderate or severe OSA group (t=-2.130, 0.278, -3.045, -2.241, 2.260, all P<0.05). Conclusion: Moderate or severe OSA may aggravate cardiac remodeling and diastolic function in ACS patients.

Air Pollutants Are Associated With Obstructive Sleep Apnea Severity in Non-Rapid Eye Movement Sleep.

The relationship between seasonal variation of obstructive sleep apnea and ambient temperature and pollutants has been inconsistent in previous studies. It is also unknown whether the seasonal variation in apnea-hypopnea index influences continuous positive airway pressure treatment dose. This study aims to examine the seasonality of obstructive sleep apnea and continuous positive airway pressure treatment, and the association between air pollutants and apnea-hypopnea index in adults with different sleep apnea severity during different sleep stages. Polysomnography of 5,413 patients referred to one sleep center during 2008-2015 were examined retrospectively. Ambient conditions and air pollutants levels were collected from the official air condition surveillance database. Cosinor analysis was used to examine seasonal variances. The general linear model was used to examine associations between air conditions and apnea-hypopnea index adjusted for seasonality. Models for apnea-hypopnea index in different sleep stages, sex groups, and obstructive sleep apnea severity groups were analyzed separately. Seasonal variations for continuous positive airway pressure treatment were not significant. Particulate matter less than or equal to 10 μm, ozone, sulfur dioxide, and relative humidity were associated with apnea-hypopnea index only in patients with severe obstructive sleep apnea. The association was significant only in non-rapid eye movement sleep. An adjustment for continuous positive airway treatment dose by season is not warranted. Protection for air pollutant-vulnerable groups should be provided. The exact mechanism of the associations between apnea-hypopnea index and air conditions only in non-rapid eye movement sleep must be clarified.

Impact of obstructive sleep apnea on pulmonary hypertension in patients with chronic obstructive pulmonary disease.

Background:Chronic obstructive pulmonary disease (COPD) and obstructive sleep apnea (OSA) syndrome are highly prevalent respiratory conditions. Their coexistence is referred to as the overlap syndrome. They are both related to pulmonary hypertension (PH) development. This study investigated the effects of OSA on PH in patients with COPD and the associated factors.Methods:Consecutive patients with stable COPD were recruited for an observational cross-sectional study from September 2016 to May 2018 at Peking University Third Hospital. In total, 106 patients with COPD were enrolled and performed home portable monitoring and echocardiography. OSA was defined by an apnea hypopnea index (AHI) ≥10 events/h. Based on OSA absence or presence, patients were divided into the COPD with OSA and COPD without OSA groups. Factors affecting pulmonary artery pressure (PAP) and PH were identified using univariate analysis and logistic regression models.Results:In the 106 patients with COPD, the mean age was 69.52 years, 91.5% were men, and the mean forced expiratory volume in 1 s (FEV1) percentage of predicted was 56.15%. Fifty-six (52.8%) patients with COPD were diagnosed with OSA, and 24 (22.6%) patients with COPD were diagnosed as PH. Compared with COPD without OSA group, the median PAP in COPD with severe OSA group increased by 5 mmHg (36.00 [26.00–50.00] mmHg vs. 31.00 [24.00–34.00] mmHg, P = 0.036). COPD with percent of night-time spent with oxygen saturation below 90% (T90) > 10% group had higher PAP than COPD with T90 ≤ 1% group (36.00 [29.00–50.00)] mmHg vs. 29.00 [25.50–34.00] mmHg, F = 7.889, P = 0.007). Univariate analysis revealed age, FEV1% predicted, T90, and Charlson index had statistically significant effects on PH. Multiple regression analysis showed a significant and independent effect of both FEV1% predicted (odds ratio [OR] = 3.46; 95% confidence interval [CI]: 1.15–10.46; P = 0.028) and AHI (OR = 3.20; 95% CI: 1.09–19.35; P = 0.034) on PH.Conclusions:Patients with COPD with OSA are more susceptible to PH, which is associated with declining lung function and increased severity of OSA. Thus, nocturnal hypoxemia and OSA in elderly patients with COPD should be identified and treated.

The Influence of Functional Endoscopic Sinus Surgery on Sleep Related Outcomes in Patients with Chronic Rhinosinusitis.

Purpose Chronic rhinosinusitis (CRS) patients often complain of nasal obstruction, which may cause sleep impairment for them. The goal of this study was to investigate the influence of functional endoscopic sinus surgery (FESS) on sleep related outcomes in CRS patients. Materials and Methods CRS patients who received FESS were included in this study. Prior to FESS and 3 months after surgery the patients were asked about the severity of nasal obstruction and completed the 20-item Sinonasal Outcome Test (SNOT-20), along with the Epworth Sleepiness Scale (ESS) questionnaire. Endoscopic examination, acoustic rhinometry, and polysomnography were performed in all patients. They were divided into four groups according to their preoperative apnea hypopnea index (AHI) scores: nonobstructive sleep apnea syndrome (non-OSAS), mild OSAS, moderate OSAS, and severe OSAS. Results A total of 96 subjects completed the study. The scores of the sleep domain of the SNOT-20 and ESS decreased in all of the AHI groups, with the exception of the severe OSAS group, after FESS. A reduction in the AHI of less than 5 was achieved in 9 patients (13.2%) after FESS. Conclusions Our results showed that FESS improved sleep quality in CRS patients, except those with severe OSAS, and a preoperative lower AHI was the only significant predictor of post-FESS OSAS outcome.

Effects of OSA Surgery on Ophthalmological Microstructures.

Obstructive sleep apnea/hypopnea syndrome (OSA) could compromise oxygenation of the optic nerve and cause glaucomatous optic neuropathy; however, there were no studies to investigate the changes of visual function and retinal microstructures in OSA patients after upper airway surgery. We aim to assess the changes in the visual sensitivity and retinal fiber layer thickness in OSA patients before and after surgery. This prospective single-blind study enrolled patients with OSA from a tertiary academic medical center who had unsuccessful conservative therapy and then underwent surgery. The patients were referred for comprehensive ophthalmologic evaluation at baseline and 6 months after OSA surgery. The polysomnographic findings were collected pre- and postoperatively. Visual sensitivities on standard automated perimetry (SAP) were assessed. Peripapillary retinal nerve fiber layer (RNFL) thickness and macular layer (ML) thickness parameters were measured by spectral-domain optical coherence tomography (OCT). A total of 108 OSA patients were enrolled. Six months after surgery, the major parameters of polysomnography (PSG), mean deviation, and pattern standard deviation of SAP significantly improved in these OSA patients. Regarding the OCT parameters, thickness of ML in the nasal-outer, superior-inner, temporal-inner, inferior-inner, nasal-inner sectors, and total ML thickness significantly increased 6 months after upper airway surgery in the severe OSA group (apnea/hypopnea index ⩾30 per hour). The visual sensitivities on SAP, ML thickness on OCT, and oxygenation status on PSG significantly improved 6 months after upper airway surgery in patients with severe OSA. Upper airway surgery may ameliorate the microstructures of the retina in patients with severe OSA.

The Relationship Between Obstructive Sleep Apnea and Coronary Plaque: A Coronary Computed Tomographic Angiography Study.

Coronary artery disease continues to be the most important cause of morbidity and mortality. Obstructive sleep apnea (OSA) is independently associated with subclinical atherosclerosis. In this study, we aimed to assess the relationship between the presence of coronary plaques and OSA and between coronary plaque burden and the severity of OSA according to plaque type. In this cross-sectional study, we enrolled 214 consecutive patients who were divided into four groups of 43 patients (age: 52.3 ± 6.4 years) without OSA, 51 patients (age: 53.9 ± 6.7 years) with mild OSA, 40 patients (age: 55.2 ± 5.9 years) with moderate OSA, and 80 patients (age: 54.9 ± 7.2 years) with severe OSA according to the apnea-hypopnea index (AHI). We performed coronary computed tomographic angiography (CCTA) and evaluated plaque positivity, the presence of non-calcified/mixed plaques, and total stenosis score for each group. The prevalence of non-calcified/mixed plaques was three times higher in the severe OSA (41.3%) group and two times higher in the moderate OSA (30.0%) group compared to the patients without OSA (14.0%). When the four groups were examined in terms of plaque burden, the total stenosis score was found to increase with the presence and severity of OSA (0.27 ± 0.85, 1.07 ± 2.44, 1.75 ± 2.85, and 2.55 ± 3.96 respectively, p = 0.001). In addition, AHI and age were independent predictors of the presence of non-calcified/mixed plaques (p < 0.001 and p = 0.007, respectively). The presence of coronary artery plaques, especially non-calcified/mixed plaques, and coronary artery stenosis as measured by CCTA was significantly associated with the severity of sleep-disordered breathing in symptomatic patients at low to intermediate risk of coronary artery disease. Prospective studies are needed to establish the relationship between plaque burden and OSA.

0580 Obstructive Sleep Apnea and Daytime QT Interval by 12-Lead ECG

The association between obstructive sleep apnea (OSA) and sudden cardiac death (SCD) has been described. A prolonged QT interval is a recognized marker of abnormal ventricular repolarization linked to increased risk of SCD. We hypothesized that patients with OSA would have more marked abnormalities in daytime QT interval. We identified consecutive patients who underwent clinically indicated diagnostic polysomnography with a 12-lead ECG at a single academic sleep center. Heart rate-corrected QT intervals (QTc) were compared by OSA severity class (normal/mild: apnea hypopnea index (AHI) <15/hr; moderate: 15-30; severe: >30) adjusting for age, sex, body mass index, hypertension, and heart failure (HF). Further evaluation was performed by dichotomizing patients into severe (AHI >30/hr) and non-severe (<30/hr) OSA. Logistic analysis was used to determine the association of OSA severity and abnormal QTc (>450msec / >470msec for men/women, respectively). A total of 249 patients (50.2% female, mean age 57.2 [12.5]) were included. This cohort had a high burden of cardiovascular disease (73% with hypertension, 20% with HF). Abnormal QTc was present in 34% of males and 31% of females. QTc increased across OSA groups (normal/mild: 435.6 msec; moderate: 431.36; severe: 444.4, p= 0.03). Patients with severe OSA had longer QTc compared with normal/mild OSA (mean difference 10.0msec [0.5,19.0], p=0.04). When stratified dichotomously, patients with severe OSA had longer QTc compared to non-severe (444.4 msec vs. 433.48 msec, p=0.004). Severe OSA was also associated with abnormal QTc (OR 2.68 [1.34,5.48], p=0.006). There was significant interaction by HF status as the difference in QTc by OSA status (non-severe vs. severe) was more prominent in patients with HF (456.1 msec [435.3-476.8] vs. 480.5 [458.9-502.1], p=0.028). In a single sleep center cohort at elevated cardiovascular risk, patients with severe OSA had a prolonged daytime QTc compared to those with normal to mild OSA. Further, the prevalence of clinically significant abnormal QTc was higher in the severe (vs. non-severe) OSA group . The presence of severe OSA may represent a novel risk of SCD particularly in patients with HF. None

Preliminary study on the relationship between OSA and renal function

Objective:To explore the relationship between obstructive sleep apnea(OSA) and renal function. Method:We collected the clinical data of 487 patients who underwent sleep monitoring in our hospital from January 2013 to December 2017 and excluded history of chronic heart disease, acute and chronic glomerulonephritis, and pyelonephritis. Among the 487 patients, 54 were in nonOSA control group and 433 were in OSA group, including 64 patients with mild OSA, 77 patients with moderate OSA, 108 patients with severe OSA, and 188 patients with extremly severe OSA. The eGFR was calculated using an equation combined serum creatinine and cystatin C. Then propensity score matching(PSM) was used to reduce differences in confounders among groups. The differences of creatinine, cystatin and eGFR between the control group and different degrees of OSA were compared, and the relationship between OSA severity and renal dysfunction was analyzed.Result:There was no statistically significant difference in creatinine between the OSA group and the control group. Serum cystatin C levels in the moderate OSA group and the extremly severe OSA group were higher compared with the control group(0.90±0.18)mg/L, (0.82±0.21) mg/L,P=0.026;(0.92±0.22) mg/L,(0.82±0.21) mg/L,P=0.006,there was no statistically significant difference in cystatin C level of mild OSA group or severe OSA group compared with the control group.The eGFR levels in the moderate OSA group and extremly severe OSA group were lower than that in the control group, 100.64±16.09, 108.57±19.31,P=0.012; 102.03±18.39, 108.57±19.31, P=0.024.After matching with the PSM, the serum cystatin C levels in the moderate OSA group and in the extremely severe OSA group were higher compared with the control group, (0.91±0.19) mg/L,P=0.028;(0.91±0.23) mg/L,P=0.031;(0.82±0.21) mg/L, but only in moderate OSA group, eGFR was lower than the control group,100.86±17.31,108.57±19.31,P<0.05. Conclusion: The renal function of OSA patients has different degrees of impairment. Renal function impairment and the severity of OSA do not show a single linear relationship.

PREVALENCE OF COGNITIVE IMPAIRMENT IN OSA AND ITS ASSOCIATION WITH THE SEVERITY OF OSA: A CROSS SECTIONAL STUDY

PURPOSE: Cognitive impairment in OSA is a widely unrecognised entity. Earlier studies have shown variable results for the prevalence of this entity. Hence, this study was done to determine the prevalence of cognitive impairment in patients diagnosed to have OSA and its association with the severity of OSA. METHODS: All inpatients and outpatients who were diagnosed to have OSA by polysomnography in a tertiary care hospital in Kerala, India were included in this study. Cognitive function was assessed by Montreal Cognitive Assessment (MoCA) and their scores calculated. Daytime sleepiness was assessed by Epworth Sleepiness Scale(ESS). RESULTS: 96 OSA patients were included in the study. 19.8% patients had mild OSA, 29.2% patients had moderate OSA and 51 % patients had severe OSA. The prevalence of cognitive impairment in OSA patients was found to be 58.3%. There were 35(62.5%) patients with cognitive impairment in the severe OSA group, while the moderate and mild OSA groups had 17(30.4%) and 4 (7.1%) patients respectively. There was a significant negative correlation between AHI and MoCA score indicating that cognitive impairment is associated with the severity of OSA. CONCLUSIONS: The prevalence of cognitive impairment in our study was 58.3%, which was found to be more in those with severe OSA. It was also found that cognitive impairment is associated with the severity of OSA. CLINICAL IMPLICATIONS: Cognitive impairment in OSA can increase the risk of automobile and workplace related accidents and affect work productivity. CPAP therapy for OSA has shown to improve cognitive function thereby improving work performance and quality of life.

The Association of Salivary Biomarkers With the Severity of Obstructive Sleep Apnea and Concomitant Hypertension

BackgroundWe aimed to assess the association between salivary alpha-amylase and salivary cortisol, and obstructive sleep apnea (OSA) severity. MethodsFifty-eight adults with suspected OSA were divided into the following 4 groups based on the apnea hypopnea index (AHI): control (AHI <5 events/hour), mild OSA (5 events/hour < AHI ≤15 events/hour), moderate OSA (15 events/hour < AHI ≤30 events/hour) and severe OSA (AHI >30 events/hour) groups. Salivary samples were collected after overnight polysomnography. Correlations between the salivary biomarkers and polysomnography parameters were analyzed. ResultsSalivary alpha-amylase levels of the moderate and severe OSA groups were significantly higher than those of the control and mild OSA groups, and no association was found between salivary cortisol and OSA severity. The salivary alpha-amylase levels were positively correlated with the AHI (r = 0.538; P < 0.01) and microarousal index (r = 0.541, P < 0.01), and negatively correlated with the lowest pulse oxygen saturation (r = −0.375, P < 0.01). Salivary cortisol levels were significantly higher in patients with hypertension than in those without hypertension (10.01 ± 2.77 ng/mL vs. 5.52 ± 1.90 ng/mL, P < 0.05), and the salivary alpha-amylase levels were highest in the OSA concomitant hypertension group (32.81 ± 11.85 U/mL). Areas under the receiver operator characteristic analysis revealed that the cutoff values of salivary alpha-amylase for identifying moderate-severe OSA and OSA concomitant hypertension were 17.64 U/mL (sensitivity 85%, specificity 91%) and 25.35 U/mL (sensitivity 70%, specificity 94%), respectively. ConclusionsSalivary alpha-amylase is positively associated with the severity of OSA and OSA concomitant hypertension.

Neuro-cognition in patients of Obstructive Sleep Apnoea Syndrome

Background: Obstructive Sleep Apnoea Hypoapnoea Syndrome (OSAHS) is known to be associated with impairment in neuro-cognitive functions. This impairment in cognition is associated with daytime sleepiness that results in occupational deficits and an increased risk of automobile accidents. Objectives: The aim of the study was to assess Neuro-cognition in patients of Obstructive Sleep Apnoea Hypoapnoea Syndrome (OSAHS) Material and methods: Our study was an observational cross-sectional study. Eligible patients (n=205) undergoing polysomnography were categorized into Snoring (n=105), Mild OSA (n=70), Moderate OSA (n=17) and Severe OSA (n=13) groups, based on Apnoea Hypoapnoea Index (AHI). The Montreal Cognitive Assessment (MoCA) and the Mini-Mental State Examination (MMSE) Questionnaires were administered to assess their cognitive functions and the correlation between Questionnaire scores and severity of OSAS was determined. Results: MMSE Questionnaire detected overall cognitive impairment in 22% of OSA patients while as MoCA Questionnaire detected overall cognitive impairment in 33% of the same OSA patients. The frequency of mild neurocognitive impairment as detected by MMSE Questionnaire increased progressively as the severity of OSA increased from Snoring(6.7%) to Mild OSA(17.1%), Moderate OSA(29.4%) and severe OSA(38.4%). MoCA Questionnaire demonstrated the same pattern except that it was more sensitive. It detected cognitive impairment of 12.4% in Snoring group, 27.1% in Mild OSA group, 41.2% in Moderate OSA group and 53.9% in Severe OSA group. Conclusion: Neurocognitive impairment is common in patients with OSAHS. The MoCA is a more sensitive tool than MMSE for the assessment of mild cognitive impairment in OSAHS patients, whose performance on the MMSE is in the normal range.

Assessment of Neurocognitive Impairment in Obstructive Sleep Apnea

Sleep apnea is usually reported in south Indian population. The indications of obstructive sleep apnea (OSA) comprise of breathing difficulties particularly owing to obstruction in the upper airway tract. The present study investigated the effect of the syndrome, the patients documented with OSA, by categorizing the patients into mild, moderate and severe OSA groups depending on apnea-hyponea index (AHI), derived from sleep study (polysomnographic findings). The comparative evaluation of various outcomes considered in this study included healthy individuals (control group, AHI 30). Investigations were conducted on the subjects which evaluated baseline characteristics, polysomnographic data and neuro-cognitive performances by Mini-Mental State Examination (MMSE). The results revealed significantly higher body mass index (BMI), snoring and decresed sleep efficiency in patients with sleep apnea syndrome when compared with control group. OSA patients further exhibited compromised neuro-cognitive. The intensity of the impairments and difficulties increased with upsurge in severity of the syndrome among all patients. The findings of this work strongly indicated that impaired executive functioning; neuro-cognitive abnormalities exit in a heightened state among OSA patients, than in the normal healthy individuals, the control group. These findings in aggregate would help clinicians in diagnosis and in understanding the disease prognosis.