The Change of Interleukin-6 and Tumor Necrosis Factor in Patients with Obstructive Sleep Apnea Syndrome

The levels of lipopolysaccharide (LPS) induced interleukin 6 (IL 6) and tumor necrosis factor α (TNF α) expression in culture of peripheral blood mononuclear cells (PBMC) and the plasma levels of IL 6 and TNF α in the patients with obstructive sleep apnea syndrome (OSAS) were measured and the relationship between OSAS and IL 6 or TNF α expression studied. Both IL 6 and TNF α were detected by using ELISA in 22 patients with OSAS and 16 normal controls. The levels of LPS induced IL 6 (787.82±151.97 pg/ml) and TNF α (4165.45±1501.43 pg/ml) expression in the supernatant of the culture of PBMC and plasma level of IL 6 (50.67±4.70 pg/ml) and TNF α (299.09±43.57 pg/ml) in the patients with OSAS were significantly higher than those in the normal controls (in the supernatant of the culture of PBMC: 562.69±197.54 pg/ml and 1596.25±403.08 pg/ml respectively; in the plasma: 12.69±2.75 pg/ml and 101.88±21.27 pg/ml respectively). There were significantly positive correlation between the levels of IL 6 and TNF α and the percentage of time of apnea and hyponea, as well as the percentage of time spending at SaO 2 below 90 % in the total sleep time. It was concluded that LPS induced IL 6 and TNF α levels as well as plasma IL 6 and TNF α levels in the patients with OSAS were up regulated, which may be associated with the pathogenesis of OSAS.

Electrical Stimulation Therapy Improves Sleep Respiratory Parameters in Obstructive Sleep Apnea Syndrome: A Meta-analysis

Recent clinical trials have shown that electrical stimulation has beneficial effects in obstruc- tive sleep apnea syndrome （OSAS）. The purpose of this study was to evaluate the efficacy of electrical stimulation therapy for OSAS with a meta-analysis. The meta-analysis of all relative studies was per- formed through searching international literature, including PUBMED, CNKI, and EMBASE databases. This literature analysis compared all patients undergoing electrical stimulation therapy with respect to the respiratory disturbance index （RDI） and changes in sleep structure. Six studies were selected in- volving a total of 91 patients. The meta-analysis indicated that electrical stimulation therapy reduced RDI, longest apnea time, and improved the minimum SaO2. Based on the evidence found, electrical stimulation may be a potential therapy for OSAS, warranting further clinical trials.

Computational Fluid Dynamics Simulation of the Upper Airway of Obstructive Sleep Apnea Syndrome by Muller Maneuver

This study aimed to use computer simulation to describe the fluid dynamic characteristics in patients with obstructive sleep apnea syndrome（OSAS） and to evaluate the difference between during quiet respiration and the Muller maneuver（MM）. Seven patients with OSAS were involved to perform computed tomographic（CT） scanning during quiet respiration and the MM. CT data in DICOM format were transformed into an anatomically three-dimensional computational fluid dynamics（CFD） model of the upper airway. The velocity magnitude, relative pressure, and flow distribution were obtained. Numerical simulation of airflow was performed to discuss how the MM affected airflow in the upper airway. To measure the discrepancy, the SPSS19.0 software package was utilized for statistic analysis. The results showed that the shape of the upper airway became narrower, and the pressure decreased during the MM. The minimal cross-sectional area（MCSA） of velopharynx was significantly decreased（P〈0.05） and the airflow velocity in MCSAs of velopharynx and glossopharynx significantly accelerated（P〈0.05） during the MM. This study demonstrated the possibility of CFD model combined with the MM for understanding pharyngeal aerodynamics in the pathophysiology of OSAS.

The Diagnosis Value and Its Implication of Impulse Oscillometry in Obstructive Sleep Apnea Syndrome Patients

The change of measurements of impulse oscillometry (105) in obstructive sleep apnea syn- drome (OSAS) patients and its mechanism were observed. The respiratory impedance was measured by using IOS technique and polysomnography (PSG) was monitored synchronously in 36 OSAS pa- tients,14 patients with chronic obstructive pulmonary disease (COPD) and 12 normal controls. Re- sults showed that R20 in OSAS group was significantly higher than in COPD group and control group (P<0.01). R5-R20 in OSAS group was lower than that in COPD group, but significantly higher than that in control group(P<0. 01). The levels of R20 and R5-R20 were positively correlated with severity degree of the disease. In addition, apnea-hyponea index (AHI) was positively correlated with R5 and R20 with the correlation index (r)being 0. 66 and 0. 86 respectively. The lowest SO2 was negatively correlated with R5 and R5-R20, with r being-0. 66 and- 0. 79 respectively. The mean SO2 was negatively correlated with R5 and R5-R20 with r being-0. 81 and-0. 69 respectively. IOS technique could be used as a valuable tool for assessing the degree of upper airway obstruction in the patients with OSAS, and could help to explore its pathological mechanism.

Meta-analysis of randomized controlled trials of traditional Chinese medicine in the treatment of obstructive sleep apnea syndrome

Objective:Though Chinese medicine(CM)has showed its clinical efficacy for the treatment of obstructive sleep apnea(OSA)in China,no systematic reviews or meta-analyses provide evidences for its therapeutic effects on OSA and the long-term safety.The aim of the present study is to evaluate the effectiveness and safety of CM on OSA using meta-analysis.Methods:We used search items of"Chinese Medicine"AND"obstructive sleep apnea"to retrieve the randomized control trials(RCTs)of CM treatments for OSA in PubMed,Embase,Cochrane Library,China National Knowledge Infrastructure(CNKI),VIP database,and Wanfang database from their respective inception dates to December 2019.Only RCTs of CM therapy versus no treatment which could be quantitatively synthesized were included.Finally,20 studies representing 1,297 participants were included after extraction.Two investigators independently extracted and analyzed the data using RevMan5.3 software.Results:The treatment group using CM decoctions or CM granules presented significantly ameliorative effects on apnoea-hypopnoea index(AHI)compared with the control group(MD:-2.58,95%CI:-3.59 to-1.56,P<0.00001 and MD:-5.47,95%CI:-6.75 to-4.19,P<0.00001,respectively)in the sensitivity analysis.However,there were non significant differences in the duration of treatment between subgroups,indicating that the duration of treatment has no impacts on the therapeutic effects on AHI.CM granules also showed significantly ameliorative effects on the lowest nocturnal oxygen saturation(LSaO2)(MD:2.76,95%CI:1.85 to 3.68,P<0.00001).CM decoctions exhibited significantly improved Epworth Sleepiness Scale(ESS)scores compared with the control group in a sensitivity analysis(MD:-1.50,95%CI:-2.13 to-0.88,P<0.00001).CM granules showed a better improvement of ESS than the control group(MD:-1.35,95%CI:-1.92 to-0.78,P<0.00001).Mild adverse reactions occurred only in five patients and disappeared without special treatment.Conclusion:This study showed favorable therapeutic efficacy of CM on OSA.However,in consideration of the low methodological quality of the included RCTs,more rigorous designed,large sample size RCTs are recommended for providing more high-quality evidences.

Prognostic predictors on the efficacy of oral appliance therapy for obstructive sleep apnea syndrome

Objectives: The aim of this study was to identify independent prognostic predictors of the efficacy of oral appliance (OA) therapy for obstructive sleep apnea syndrome (OSAS). Materials and methods: The subjects consisted of 89 patients (77 males and 12 females) in whom OSAS had been treated with an OA. The mean age of the subjects was 52.4 years (range: 20 to 78 years) and mean body mass index (BMI) was 23.9 kg/m2 (range: 17.3 to 32.2 kg/m2). Lateral cephalograms were taken and 15 angle, 15 distance and 5 area measurements were calculated by means of a computerized program. Overnight polysomnography (PSG) was performed before treatment and several months after titration of OA therapy. OA therapy was considered effective if the apnea-hypopnea index several months after titration was under 15 events/h and was reduced to at least 50% of that before treatment. The examined data such as patient age, sex, BMI, data from cephalometric analyses, Epworth sleepiness scale, and data for pretreatment PSG were analyzed statistically, and multivariate logistic regression analysis was performed to clarify predictive variables for treatment outcome. Results: LFH (OR = 0.350;p = 0.035) and McN-A (OR = 0.276;p = 0.057) were selected as independent predictors from the explanatory variables. The predictive accuracy of the calculated logistic regression model was 74.2%. Conclusion: This results show that OA therapy for OSAS is more effective in patients with large anteroposterior diameter of the maxilla and large lower facial height.

A Case of Giant Epidermoid Cyst in the Floor of the Mouth That Caused Severe Obstructive Sleep Apnea Syndrome

We describe here, a case with a giant epidermoid cyst in the floor of the mouth that caused severe obstructive sleep apnea syndrome (OSAS). A 37-year-old man was referred to our clinic because of a swelling in the floor of his mouth and sleep apnea syndrome. The occurrence of breathing disorders and daytime drowsiness was monitored to evaluate his OSAS 1 day before and 7 days after surgery. Before surgery, the apnea-hyponea index (AHI) and Epworth Sleepiness Scale (ESS) were 45.7 and 22, respectively. The clinical diagnosis was a dermoid or an epidermoid cyst that caused severe OSAS. Under general anesthesia, the patient underwent intraoral surgical removal of the cyst, along with aspiration to reduce the mass. After surgery, his sleep apnea syndrome was significantly improved. The postoperative AHI and ESS were 5.5 and 7, respectively. As of 2 years after the operation, there was no evidence of recurrence.

The Treatment Strategy of Patients with Sleep Apnea Syndrome in Our Department and Subsequent Course

It is known that acute or chronic heart failure can develop in patients with grave sleep apnea syndrome (SAS), and known to have the social problem including an accident and the decrease of the labor will. Several medical treatments are now available for SAS. We considered problems of the treatment based on the practice situation of our department about the present conditions and subsequent treatment. The subjects consisted of 306 patients. We measured Epworth Sleepiness Scale (ESS) and apnea hypopnea index (AHI) after polysomnography in all patients at the first time and 6 months later. So, it was found that AHI and ESS decreased when we could be treated in the SAS patients appropriately. It was confirmed that the choice of the appropriate regimen was important.

The Comparison of Clinical analysis of Chinese and German Patients with Obstructive Sleep Apnea Syndrome

Objective:To compare the sex ratio,age distribution,severity of the illness,comorbidities,and the treatment of the patients with obstructive sleep apnea syndrome in China and Germany.Methods:A retrospective study of the data was conducted,and a total of 200 patients diagnosed with obstructive sleep apnea syndrome in Germany and China from March 2013 to October 2015 were analyzed.The sex ratio,age distribution,severity of the illness,comorbidities and treatment methods were analyzed.Results:There was no significant difference in the severity of disease,sex ratio,and age distribution between the patients with obstructive sleep apnea syndrome in China and Germany(P>0.05).In terms of comorbidities,the combination of moderate and severe patients in the German group,compared with the moderate and severe patients in the Chinese group,except for cerebrovascular disease,the comorbidities were less than those in the Chinese group(P<0.05),the difference was statistically significant.In terms of treatment,the patients in the German group were compared with the patients in the Chinese group with light,moderate,and severe patients.Except for the German patients who received oral appliances and surgical treatment,more patients were treated than Chinese patients(P<0.05),the difference is statistically significant.Conclusion:The two country(Germany and China)are basically the same in the diagnosis and treatment of obstructive sleep apnea syndrome,but Germany pays more attention to details and individualization in treatment.

Effects of China-Germany Follow Up Systems on Ventilator Therapy in Patients with Obstructive Sleep Apnea Syndrome

Objective:To investigate the effects of different follow-up systems in China and Germany on ventilator therapy in patients with obstructive sleep apnea syndrome.Method:From March 2013 to October 2015,three hundred patients with moderate to severe obstructive sleep apnea syndrome and those who are suitable for ventilator treatment were followed up according to the follow-up system of both China and Germany.The follow-up was carried out for one year to compare the rate of loss to follow-up,ventilator therapy compliance,treatment effect,ventilator side effects and others in the two groups of patients.Statistical analysis was performed using x2 test,P<0.05 for the difference was statistically significant.Results:The rate of loss to follow-up in the German group was lower than that in the Chinese group.The compliance of the German group with respiratory therapy was lower than that of the Chinese group.The side effects of ventilator treatment were lower than those in the Chinese group(P<0.05).Conclusion:The German follow-up system is more effective than the Chinese follow-up system in improving the compliance and effectiveness of ventilator therapy in patients with obstructive sleep apnea syndrome.

COGNITIVE AND EMOTIONAL IMPAIRMENT IN OBSTRUCTIVE SLEEP APNEA SYNDROME

Objective To evaluate the emotional and cognitive status in patients with obstructive sleep apnea syndrome (OSAS), using neuropsychological tests and evoked-related potential (P3). Methods Sixteen patients diagnosed of OSAS were tested by Hamilton rating scale for anxiety (HRSA) and Hamilton rating scale for depression (HRSD). Other three groups, OSAS patient group (n=21), snoring group (n=21), and control group (n=21), were administered polysomnography (PSG), auditory evoked event-related potential (P3), and clinic memory test. The results were analyzed using general linear model (GLM) analysis and Post Hoc test. Results Twelve OSAS patients’ scores of HRSA and HRSD were beyond the normal range, 26.42 ±4.48 and 22.08 ±3.97 respectively. The auditory P3 latency in OSAS group was 363.1 ±22.9 ms (Fz), 368.57 ±28.03 ms (Cz), in snoring group 336.57 ±31.08 ms (Fz), 339.81 ±31.76 ms (Cz), in control group 340.8 ±28.7 ms (Fz), 338.29 ±29.21 ms (Cz). There were significant differences between OSAS group and snoring group, as well as control group (P< 0.05). No significant difference was seen between snoring group and control group. No significant difference was noted in P3 amplitude among three groups. Memory quotient (MQ) reduced in snoring group compared with control group. Conclusions Emotional disturbances are common clinical features in OSAS patients. Abnormal auditory P3 latency indicates the cognitive dysfunction in OSAS patients. Nocturnal hypoxaemia may play an important role on it. Snorers should be monitored because of the tendency to develop cognitive impairment.

Retinal nerve fiber layer thickness changes in obstructive sleep apnea syndrome: one year follow-up results

·AIM: To investigate the retinal nerve fiber layer(RNFL)thickness changes in patients with obstructive sleep apnea syndrome(OSAS) for one year follow-up. To discuss the possibility of detecting tendency of glaucoma in this population by using spectral domain optical coherence tomography(3D-OCT-2000 Spectral domain).·METHODS: After polysomnographic study, all subjects(64 OSAS patients and 40 controls) underwent detailed ophthalmological examination. After these examinations,patients with glaucoma and patients who had ophthalmological and/or systemic disease were excluded from the study.Totally, 20 patients in OSAS group and five patients in controls were excluded from the study in the first examination and follow-up period. The RNFL thickness was assessed with OCT. Forty-four OSAS patients and 35 control subjects were followed up for12 mo. RNFL thickness change and OSAS patients were evaluated for severity of disease by Apnea-Hypopnea Index(AHI).·RESULTS: Forty-four OSAS patients and 35 controls were enrolled in the study. Statistically significance was found between OSAS patients and controls at the 12 thmo.Average RNFL thickness was found to be significantly lower in last measurements in OSAS patients when compared with first measurements and control subjects(P 【0.001, 0.002, respectively). There was a statistically significant correlation among AHI, and RNFL thickness(P 【0.05).·CONCLUSION: The results suggest that the patients with OSAS were related with a proportional decrease in the RNFL thickness. These patients should be followed up regularly for glaucomatous changes. Detecting more RNFL thinning in severe OSAS was important.

Evaluation of choroidal thickness using spectral-domain optical coherence tomography in patients with severe obstructive sleep apnea syndrome: a comparative study

AIM: To assess choroidal thickness in patients with severe obstructive sleep apnea syndrome(OSAS) and compare them with healthy controls, using spectral domain optical coherence tomography(OCT).METHODS: In this observational, cross-sectional study,choroidal thicknesses of 23 newly severe OSAS patients and 23 body mass index- age- and sex-matched healthy subjects were measured using a high-speed, high-resolution frequency domain- OCT device( λ = 840 nm,26 000 A-scans/s, 5 μm axial resolution). All patients underwent a complete ophthalmic examination before the measurements. OCT measurements were taken at the same time of day(9:00 a.m.), in order to minimize the effects of diurnal variation.RESULTS: There was a statistically significant difference in median choroidal thickness between the OSAS patients(201 μm; range 145-237 μm) and the controls(324 μm; range 296-383 μm;P 【0.001). There were significant differences at all measurement points(P 【0.001 for all). The apnea-hypopnea index(AHI)values were more than 30 in all OSAS patients and the mean AHI was 48.57 ±6.54. The interexaminer intraclass correlation coefficient(ICC) for the mean choroidal thickness was 0.938(95% CI, 0.908-0.985) and ICC was greater than 0.90 for all measurement points.CONCLUSION: The decreased choroidal thickness of patients with severe OSAS might be related to the the autonomic disregulation associated with this disease.Further studies are needed to evaluate the etiopathologic relationship between choroidal thickness and OSAS.

Retinal nerve fiber layer thickness changes in obstructive sleep apnea syndrome:a systematic review and Metaanalysis

AIM： To evaluate the retinal nerve fiber layer（RNFL）thickness changes in patients with obstructive sleep apnoea syndrome（OSAS）, and detect possible prevalence of glaucoma in this population.METHODS： Comprehensive studies were conducted on the Cochrane Library, Pub Med and Embase through March, 2015. Only studies that fit the selection criteria about RNFL and OSAS would be included. For the measures, we calculated the 95% confidence interval（CI）and weighted mean differences（WMD）. The systematic review and Meta-analysis was performed by Rev Man 5.2software.RESULTS： Nine case-control studies were analyzed containing a total of 1086 cases and 580 controls.Average RNFL thickness in OSAS was reduced significantly compared with healthy controls in random effects model（WMD =-2.56, 95% CI：-4.82 to-0.31, P =0.003, I2=57%）. A significant RNFL thickness reduction were found between the two groups in inferior quadrant（WMD =-3.11, 95% CI：-5.53 to-0.69, P =0.01）, superior quadrant（WMD =-2.37, 95% CI：-4.7 to 0.04, P =0.05）. In nasal quadrant（WMD =-2.54, 95% CI：-6.53 to 1.45, P =0.21） and temporal quadrant（WMD=-1.26, 95% CI：-2.19 to 0.47, P =0.15） there was no difference of RNFL thickness between the two groups.CONCLUSION： The results show that RNFL thickness is lower in patients with moderate or severe OSAS than in normal subjects or patients with mild OSAS according to the nine homogeneity studies.

A Very Severe Obstructive Sleep Apnea Syndrome: In a Cause of Resistant Hypertension with One Sample Case

When blood pressure values remain above the target in a hypertensive patient treated concomitantly with three anti-hypertensive drugs including a diuretic, maximum well-tolerated doses, this is a resistant arterial hypertension. In this case, it is advisable to look for a secondary cause such as a drug intake that influencing the blood pressure or the presence of obstructive sleeping syndrome (OSAS). We report a clinical case of a patient with a high cardiovascular risk at the age of 50, hypertensive and diabetic, with dyslipidemia and obesity. He was on anti-hypertensive triple therapy at an optimal dose. Her diabetes was balanced with 6.4% glycated hemoglobin. Dyslipidemia has being treated. Despite healthy diet including a low sodium diet and weight loss, blood pres- sure target was not reached. With self-measurement, the mean arterial pressure was 180/110 mmHg and on ABPM it was 167/113 mmHg. The ventilatory polygraphy finds a severe OSA with an IAH = 56.6. Treatment with PCP (Con- tinuous positive pressure) allowed this patient to control blood pressure. The search for OSA should be systematic in face of resistant hypertension, in par- ticular in overweight or obese patients.

Obstructive Sleep Apnea Syndrome Phenotyping by Cluster Analysis: Typical Sleepy, Obese Middle-aged Men with Desaturating Events are A Minority of Patients in A Multi-ethnic Cohort of 33% Women

Objective Several clinical obstructive sleep apnea syndrome(OSAS)phenotypes associated with heterogeneous cardiovascular risk profiles have been recently identified.The purpose of this study was to identify clusters amongst these profiles that allow for the differentiation of patients.Methods This retrospective study included all moderate-to-severe OSAS patients referred to the sleep unit over a 5-year period.Demographic,symptom,comorbidity,polysomnographic,and continuous positive airway pressure(CPAP)adherence data were collected.Statistical analyses were performed to identify clusters of patients.Results A total of 567 patients were included(67%men,54±13 years,body mass index:32±7 kg/m2,65%Caucasian,32%European African).Five clusters were identified:less severe OSAS(n=172);healthier severe OSAS(n=160);poorly sleeping OSAS patients with cardiometabolic comorbidities(n=87);younger obese men with sleepiness at the wheel(n=94);sleepy obese men with very severe desaturating OSAS and cardiometabolic comorbidities(n=54).Patients in clusters 3 and 5 were older than those in clusters 2 and 4(P=0.034).Patients in clusters 4 and 5 were significantly more obese than those in the other clusters(P=0.04).No significant differences were detected in terms of symptoms and comorbidities.Polysomnographic profiles were very discriminating between clusters.CPAP adherence was similar in all clusters but,among adherent patients,daily usage was more important in cluster 1(less severe patients)than in cluster 5.Conclusion This study highlights that the typical sleepy obese middle-aged men with desaturating events represent only a minority of patients in our multi-ethnic moderate-to-severe OSAS cohort of 33%females.

CLINICAL ANALYSIS OF OBSTRUCTIVE SLEEP APNEA SYNDROME WITH ACUTE RESPIRATORY FAILURE

Objective To study the clinical characteristics of obstructive sleep apnea syndrome (OSAS) induced acute respiratory failure. Methods The clinical and laboratory character,isties of 9 patients were reviewed. Results 9 patients (8 females, 1 male) presented with obesity and mental disturbance, with a BMI heing 44. 97 kg/m2, (45. 25 kg/m2 in the female). The mean age of the group wes 67. 89 years (61 ~ 74 years). All had respiratory acidosis (mean pH 7. 17), hypercapnia (mean PaCO2 94. 10mmHg) (63. 97 ~ 143. 18mmHg), and hypoxemia (mean PaO2 39mmHg ) (29. 03 ~ 44. 03mmHg). During periods of clinical stability all but 2 had awaken hypercapnia (mean PaCO2 46. 73mmHg) (38. 25 ~ 54. 68mmHg). Four of the 9 patients had pulmonary function test showing FEV1 > 70%. Conclusion OSAS induced acute respiratory fail- ure has a sudden onset and curious presentations and can be reversed with early and proper treatment. The seventy of abnormal pulmonary function wes less than what could be expeted to cause respiratory.atory failure.

Obstructive sleep apnea syndrome and fatty liver: Association or causal link?

Obstructive sleep apnea (OSA) is a complex disorder that consists of upper airway obstruction, chronic intermittent hypoxia and sleep fragmentation. OSA is well known to be associated with hypoxia, insulin resistance and glucose intolerance, and these factors can occur in the presence or absence of obesity and metabolic syndrome. Although it is well established that insulin resistance, glucose intolerance and obesity occur frequently with non-alcoholic fatty liver disease (NAFLD), it is now becoming apparent that hypoxia might also be important in the development of NAFLD, and it is recognized that there is increased risk of NAFLD with OSA. This review discusses the association between OSA, NAFLD and cardiovascular disease, and describes the potential role of hypoxia in the development of NAFLD with OSA.

Changes in Plasma Angiotensin II and Circadian Rhythm of Blood Pressure in Hypertensive Patients with Sleep Apnea Syndrome Before and After Treatment

Objective To explore the changes in plasma angiotensin II （Ang Ⅱ） and circadian rhythm of blood pressure among hypertensive patients with sleep apnea syndrome （SAS） before and after continuous positive airway pressure （CPAP） or surgical treatment. Methods A total of 180 essential hypertension patients were enrolled in our study. The determination of plasma Ang Ⅱ concentration, ambulatory blood pressure （ABP）, and polysomnography （PSG） monitoring were performed before and 3 months after CPAP or surgical treatment. Results Patients were classified into three groups by their apnea-hypopnea index （AHI）： essential hypertension group （EH group, n=72; AHI〈5）, essential hypertension with mild SAS group （EH＋mild SAS group, n=60, 5≤AHI〈20）, and essential hypertension with moderate and severe SAS group （EH＋moderate-severe SAS group, n=48, AHI_〉20）. The concentrations of plasma AngⅡ in the above three groups were 13.42±3.27, 16.17±3.82, and 18.73±4.05 ng/mL respectively before treatment, and AngⅡ concentration in EH patients combined with SAS was significantly higher than that in EH group （all P〈0.05）. After treatment the values in the latter two groups significantly decreased to 14.67±2.56 and 15.03±3.41 ng/mL respectively （P〈0.05）. The incidence of non-dipper blood pressure curve in EH patients was 31.9%, and those in hypertensive patients with mild SAS and moderate-severe SAS were 51.7% and 58.3%, respectively before treatment. The incidence of non-dipper blood pressure curve in the EH patients with mild SAS was significantly higher than that of patients with EH alone （P〈0.05）. After CPAP treatment or surgery, the incidence of non-dipper blood pressure curve in the two SAS groups was significantly decreased to 38.3% and 39.6%, respectively （P〈0.05）. Conclusions Ang Ⅱ might play a role in blood pressure variability in patients with obstructive SAS. CPAP or surgical treatment can improve blood pressure disorder and decrease plasma Ang Ⅱ level in patients with obstructive SAS.

Stem/progenitor cells and obstructive sleep apnea syndrome - new insights for clinical applications

Obstructive sleep apnea syndrome(OSAS) is a widespread disorder, characterized by recurrent upper airway obstruction during sleep, mostly as a result of complete or partial pharyngeal obstruction. Due to the occurrence of frequent and regular hypoxic events, patients with OSAS are at increased risk of cardiovascular disease, stroke, metabolic disorders, occupational errors, motor vehicle accidents and even death. Thus, OSAS has severe consequences and represents a significant economic burden. However, some of the consequences, as well as their costs can be reduced with appropriate detection and treatment. In this context, the recent advances that were made in stem cell biology knowledge and stem cell- based technologies hold a great promise for various medical conditions, including respiratory diseases. However, the investigation of the role of stem cells in OSAS is still recent and rather limited, requiring further studies, both in animal models and humans. The goal of this review is to summarize the current state of knowledge regarding both lung resident as well as circulating stem/progenitor cells and discuss existing controversies in the field in order to identify future research directions for clinical applications in OSAS. Also, the paper highlights the requisite for inter-institutional, multi-disciplinary research collaborations in order to achieve breakthrough results in the field.