Causal role of immune cells in obstructive sleep apnea hypopnea syndrome:Mendelian randomization study

BACKGROUND Despite being one of the most prevalent sleep disorders,obstructive sleep apnea hypoventilation syndrome(OSAHS)has limited information on its immunologic foundation.The immunological underpinnings of certain major psychiatric diseases have been uncovered in recent years thanks to the extensive use of genome-wide association studies(GWAS)and genotyping techniques using highdensity genetic markers(e.g.,SNP or CNVs).But this tactic hasn't yet been applied to OSAHS.Using a Mendelian randomization analysis,we analyzed the causal link between immune cells and the illness in order to comprehend the immunological bases of OSAHS.AIM To investigate the immune cells'association with OSAHS via genetic methods,guiding future clinical research.METHODS A comprehensive two-sample mendelian randomization study was conducted to investigate the causal relationship between immune cell characteristics and OSAHS.Summary statistics for each immune cell feature were obtained from the GWAS catalog.Information on 731 immune cell properties,such as morphologic parameters,median fluorescence intensity,absolute cellular,and relative cellular,was compiled using publicly available genetic databases.The results'robustness,heterogeneity,and horizontal pleiotropy were confirmed using extensive sensitivity examination.RESULTS Following false discovery rate(FDR)correction,no statistically significant effect of OSAHS on immunophenotypes was observed.However,two lymphocyte subsets were found to have a significant association with the risk of OSAHS:Basophil%CD33dim HLA DR-CD66b-(OR=1.03,95%CI=1.01-1.03,P<0.001);CD38 on IgD+CD24-B cell(OR=1.04,95%CI=1.02-1.04,P=0.019).CONCLUSION This study shows a strong link between immune cells and OSAHS through a gene approach,thus offering direction for potential future medical research.

Obstructive sleep apnea-hypopnea syndrome immunological relationship

Obstructive sleep apnea-hypopnea syndrome(OSAHS)is a complex disorder cha-racterized by symptoms resulting from intermittent hypoxia and hypopnea,with research indicating a crucial role of immune system dysregulation and genetic variations in its pathogenesis.A recent Zhao et al study utilizes Mendelian ran-domization analysis to explore the causal relationship between immune cell characteristics and OSAHS.The study identifies specific lymphocyte subsets as-sociated with OSAHS,providing valuable insights into the disease's pathophy-siology and potential targets for therapeutic intervention.The findings underscore the significance of genetic and immunological factors in sleep disorders,offering a fresh perspective on OSAHS's complexities.Compared to existing literature,Zhao et al's study stands out for its focus on genetic markers and specific immune responses associated with OSAHS,expanding upon previous research primarily centered on systemic inflammation.In conclusion,the study represents a signi-ficant advancement in the field,shedding light on the causal role of immune cells in OSAHS and paving the way for future research and targeted treatments.

Risk factors and management countermeasures for obstructive sleep apnea hypoventilation syndrome in children

BACKGROUND Obstructive sleep apnea hypoventilation syndrome(OSAHS)in children is a sleep respiratory disorder characterized by a series of pathophysiologic changes.Statistics in recent years have demonstrated an increasing yearly incidence.AIM To investigate the risk factors for OSAHS in children and propose appropriate management measures.METHODS This study had a case–control study design.Altogether,85 children with OSAHS comprised the case group,and healthy children of the same age and sex were matched at 1:1 as the control group.Basic information,including age,sex,height,weight and family history,and medical history data of all study participants were collected.Polysomnography was used to detect at least 8 h of nocturnal sleep.All participants were clinically examined for the presence of adenoids,enlarged tonsils,sinusitis,and rhinitis.RESULTS The analysis of variance revealed that the case group had a higher proportion of factors such as adenoid grading,tonsil indexing,sinusitis,and rhinitis than the control group.CONCLUSION A regression model was established,and glandular pattern grading,tonsil indexing,sinusitis,and pharyngitis were identified as independent risk factors affecting OSAHS development.

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.

Burdened breaths:The influence of depression on obstructive sleep apnea

Depression and metabolic syndrome could exacerbate the risks of the other,leading to a series of severe coexisting conditions.One notable comorbidity that must be mentioned is obstructive sleep apnea(OSA).Current studies suggested that depression increases susceptibility to OSA.As the prevalence of depression rises,it becomes critical to prevent and manage its complications or comorbidities,including OSA.Predictive models,non-invasive electroencephalogram moni-toring,genetic research,and other promising technologies are being applied to the prevention,diagnosis,and personalized treatment of depression and OSA.

Investigation on Risk Factors of Cerebrocardiac Vascular Thrombotic Diseases in Patients with Obstructive Sleep Apnea Hypopnea Syndrome

Objective: To observe the risk factors of thrombosis in patients with obstructive sleep apnea hypopnea syndrome (OSAHS).Methods: From February 2001 to April 2003, 24 patients with moderate and severe OSAHS (OSAHS group) and 19 healthy adults (control group) were recruited. Their blood samples were drawn at 6∶00 and 16∶00 respectively for testing hemocrit, platelet aggregation (PAG), whole blood viscosity (WBV), prothrombin time (PT), activated partial thromboplastin time (APTT), plasma fibrinogen (Fng) and endothelin (ET).Results: There was a significantly higher hemocrit, WBV, Fng and ET as well as a significant shortening of PT and APTT at 6∶00 than that at 16∶00 in OSAHS group. However, there was no significant difference in all testing items between 6∶00 and 16∶00 in control group. The hemocrit, WBV, PAG, plasma Fng and ET were significantly higher, and PT and APTT were obviously shorter at 6∶00 in OSAHS group than those at 6∶00 in control group. A higher hemocrit, PAG, plasma Fng and ET, a longer PT and APTT were observed at 16∶00 in OSAHS group, compared with those at 16∶00 in control group.Conclusion: In OSAHS patients there were striking risk factors of thrombosis, which is more remarkable in the early morning than in the afternoon.

Relationship between brain—derived neurotrophic factor and cognitive function of obstructive sleep apnea/hypopnea syndrome patients

Objective:To determine the relationship between the blood serum brain-derived neurotrophic factor（BDNF） level and cognitive function deterioration in patients with obstructive sleep apnea/ hypopnea syndrome（OSAHS）,and to explore the possible mechanism of cognitive impairment. Methods:Twenty-eight male OSAHS patients and 14 normal males（as controls） were enrolled in the study.Polysomnography and the Montreal cognitive assessment（MoCA） were conducted. The blood serum BDNF levels were measured using ELISA.Results:The OSAHS group had significantly decreased blood serum BDNF levels compared with the control group（t=-10.912, P=0.000）.The blood serum BDNF level of the subjects was significantly positively associated with the MoCA score（r=0.544,P=0.000）,significantly negatively associated with the apneahypopnea index（AHI） and shallow sleep（S1+S2）（AHI:r=-0.607,P=0.000;S1+S2:r =-0.768,P= 0.000）,and significantly positively associated with the lowest SaO2（LSO）,slow wave sleep（S3+S4）, and rapid eye movement sleep（REM）（LSO:r=0.566,P = 0.000;S3+S4:r=0.778,P=0.000;REM: r=0.575,P=0.000）.Conclusions:OSAHS patients have significantly decreased blood serum BDNF levels compared with the control.Nocturnal hypoxia as well as the deprivation of slow wave sleep and REM may lead to the decreased serum BDNF level of OSAHS patients.This decreased blood serum BDNF level may contribute to the cognitive impairment in OSAHS.

Association between Serum Homocysteine and Oxidative Stress in Elderly Patients with Obstructive Sleep Apnea/hypopnea Syndrome

Objective Elderly patients with obstructive sleep apnea/hypopnea syndrome （OSAHS） has a higher risk of cardiovascular and cerebrovascular disease. However, changes of homocysteine （Hey） as markers of cardiovascular and eerebrovascular disease associated with OSAHS and their mechanism have not been elucidated so far. This study aims to investigate the changes of both serum Hcy and oxidative stress and their possible links with OSAHS in elderly patients. Methods Based on polysomnogram （PSG） and age, 83 patients with OSAHS were recruited and divided into elderly-OSAHS （n=32） and non-elderly OSAHS groups （n=51）. Fifty two subjects without OSAHS were divided into elderly control （n=29） and non-elderly control groups （n-23）. A total of 135 subjects were included in the present study. All subjects were recorded for PSG variables and the contents of homocysteine （Hcy）, malonaldehyde （MDA）, and glutathione （GSH） which were detected after sleep. Serum homocysteine was measured by cyclophorase. MDA and GSH were measured by speetrophotometer. Results （1） The serum levels of Hcy showed significant difference among the four groups （P〈0.05）. The concentrations of Hcy in elderly OSAHS patients were higher than in other groups, while those in the elderly control group were higher than in the non-elderly control; the concentrations in the non-elderly OSAHS group were higher than in the non-elderly control. （2） The concentrations of MDA and GSH changed at an equal pace with Hcy in the four groups. （3） Multielement linearity regression analysis indicated a statistically significant relationship between Hcy concentration and age, MDA, GSH, and apnea hypopnea index （AHI）. Conclusions （1） The concentrations of Hcy and oxidative stress have increased with advancing age. （2） The concentrations of Hcy and oxidative stress have further increased in the elderly patients with OSAHS. （3） Oxidative stress might cause high-level serum Hcy in the elderly patients with OSAHS.

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.

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.

Detection of cognitive impairment in patients with obstructive sleep apnea hypopnea syndrome using mismatch negativity

In this experiment, 97 patients with obstructive sleep apnea hypopnea syndrome were divided into three groups （mild, moderate, severe） according to minimum oxygen saturation, and 35 healthy subjects were examined as controls. Cognitive function was determined using the mismatch negativity paradigm and the Montreal Cognitive Assessment. The results revealed that as the disease worsened, the mismatch negativity latency was gradually extended, and the amplitude gradually declined in patients with obstructive sleep apnea hypopnea syndrome. Importantly, mismatch negativity latency in severe patients with a persistent time of minimum oxygen saturation 〈 60 seconds was significantly shorter than that with a persistent time of minimum oxygen saturation 〉 60 seconds. Correlation analysis revealed a negative correlation between minimum oxygen saturation latency and Montreal Cognitive Assessment scores. These findings indicate that intermittent night-time hypoxemia affects mismatch negativity waveforms and Montrea Cognitive Assessment scores. As indicators for detecting the cognitive functional status of obstructive sleep apnea hypopnea syndrome patients, the sensitivity of mismatch negativity is 82.93%, the specificity is 73.33%, the accuracy rate is 81.52%, the positive predictive value is 85.00%, the negative predictive value is 70.21%, the positive likelihood ratio is 3, and the negative likelihood ratio is 0.23. These results indicate that mismatch negativity can be used as an effective tool for diagnosis of cognitive dysfunction in obstructive sleep apnea hypopnea syndrome patients.

Evaluation of Airway Obstruction at Soft Palate Level in Male Patients with Obstructive Sleep Apnea/Hypopnea Syndrome:Dynamic 3-Dimensional CT Imaging of Upper Airway

This study examined the dynamic characteristics of upper airway collapse at soft palate level in patients with obstructive sleep apnea/hypopnea syndrome（OSAHS） by using dynamic 3-Dimensional（3-D） CT imaging.A total of 41 male patients who presented with 2 of the following symptoms,i.e.,daytime sleepiness and fatigue,frequent snoring,and apnea with witness,were diagnosed as having OSAHS.They underwent full-night polysomnography and then dynamic 3-D CT imaging of the upper airway during quiet breathing and in Muller＇s maneuver.The soft palate length（SPL）,the minimal cross-sectional area of the retropalatal region（mXSA-RP）,and the vertical distance from the hard palate to the upper posterior part of the hyoid（hhL） were compared between the two breathing states.These parameters,together with hard palate length（HPL）,were also compared between mild/moderate and severe OSAHS groups.Association of these parameters with the severity of OSAHS [as reflected by apnea hypopnea index（AHI） and the lowest saturation of blood oxygen（LSaO2）] was examined.The results showed that 31 patients had severe OSAHS,and 10 mild/moderate OSAHS.All the patients had airway obstruction at soft palate level.mXSA-RP was significantly decreased and SPL remarkably increased during Muller＇s maneuver as compared with the quiet breathing state.There were no significant differences in these airway parameters（except the position of the hyoid bone） between severe and mild/moderate OSAHS groups.And no significant correlation between these airway parameters and the severity of OSAHS was found.The position of hyoid was lower in the severe OSAHS group than in the mild/moderate OSAHS group.The patients in group with body mass index（BMI）≥26 had higher collapse ratio of mXSA-RP,greater neck circumference and smaller mXSA-RP in the Muller＇s maneuver than those in group with BMI26（P0.05 for all）.It was concluded that dynamic 3-D CT imaging could dynamically show the upper airway changes at soft palate level in OSAHS patients.All the OSAHS patients had airway obstruction of various degrees at soft palate level.But no correlation was observed between the airway change at soft palate level and the severity of OSAHS.The patients in group with BMI≥26 were more likely to develop airway obstruction at soft palate level than those with BMI26.

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.

Intermittent hypoxia is involved in gut microbial dysbiosis in type 2 diabetes mellitus and obstructive sleep apnea-hypopnea syndrome

BACKGROUND Obstructive sleep apnea(OSA)-hypopnea syndrome(OSAHS)has been recognized as a comorbidity of type 2 diabetes mellitus(T2DM);more than half of T2DM patients suffer from OSAHS.Intermittent hypoxia(IH)plays an important role in metabolic diseases,such as obesity and OSAHS,through various mechanisms,including altering the gut microecological composition and function.Therefore,it is important to study the role of gut microbiota in T2DM patients with OSAHS,which has a high incidence and is prone to several complications.AIM To assess whether IH is involved in altering the fecal microbiome in T2DM patients with OSAHS.METHODS Seventy-eight participants were enrolled from Henan Province People’s Hospital and divided into healthy control(HC,n=26),T2DM(n=25),and T2DM+OSA(n=27)groups based on their conditions.The fecal bacterial DNA of the research participants was extracted and subjected to 16S ribosomal RNA sequencing.The clinical indices,such as insulin resistance index,homocysteine(HCY)concentration,and the concentrations of inflammatory factors in the peripheral blood,were assessed and recorded.RESULTS Group T2DM+OSA had the highest apnea-hypopnea index(AHI)(2.3 vs 3.7 vs 13.7),oxygen desaturation index(0.65 vs 2.2 vs 9.1),HCY concentration(9.6μmol/L vs 10.3μmol/L vs 13.81μmol/L)and C-reactive protein(CRP)concentrations(0.3 mg/L vs 1.43 mg/L vs 2.11 mg/L),and lowest mean oxygen saturation(97.05%vs 96.6%vs 94.7%)among the three groups.Twelve and fifteen key differences in amplicon sequence variants were identified when comparing group T2DM+OSA with groups T2DM and HC,respectively.We found progressively decreased levels of Faecalibacterium,Eubacterium,and Lachnospiraceae,and an increase in the level of Actinomyces,which strongly correlated with the HCY,CRP,fasting plasma glucose,and hemoglobin A1c concentrations,AHI,mean oxygen saturation,and insulin resistance index in group T2DM+OSA(P<0.05).CONCLUSION For T2DM patients with OSAHS,IH may be involved in selective alterations of the gut microbiota,which may affect the pathophysiological development of T2DM and DM-related complications.

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.

Diurnal changes in retinal nerve fiber layer thickness with obstructive sleep apnea/hypopnea syndrome

AIM： To compare the retinal nerve fiber layer （RNFL） thickness in the morning and evening in Thai patients with varying degrees of obstructive sleep apnea/ hypopnea syndrome （OSAHS）. METHODS： In this cross-sectional study, potential OSAHS patients at Siriraj Hospital underwent polysomnography to determine the severity of OSAHS and an eye examination （including best corrected visual acuity, slit-lamp examination, and Goldmann applanation tonometry）. RNFL thickness was recorded once in the morning and once in the evening, using spectral domain optical coherence tomography. Thickness was expressed as an average and given for each quadrant. Patients with ocular or systemic diseases that might affect RNFL thickness were excluded. RESULTS： Forty-one eyes of 41 patients were classified into 40SAHS groups. The average and mean RNFL thickness in most of the four quadrants of the severe OSAHS group trended toward being less than those in the comparable quadrants of the other groups in both the morning and evening. In the moderate OSAHS group, the average RNFL thickness and temporal and superior quadrant thickness in the morning were significantly higher than in the evening （P=0.01, P=0.01, and P=0.03, respectively）. In the severe OSAHS group, the inferior quadrant thickness in the morning was significantly higher than in the evening （P =0.03）. CONCLUSION： The RNFL thickness in the morning was higher than in the evening in moderate OSAHS.

Correlation between metabolic syndrome and sleep apnea

The so-called "metabolic syndrome"(MS),constitutes a cluster of metabolic and cardiovascular abnormalities,including fasting glucose,blood pressure,triglycerides,high density lipoprotein cholesterol(HDL-C),and waist circumference that arise from insulin resistance. Obstructive sleep apnea(OSA) syndrome is characterized by recurrent episodes of partial or complete obstruction of the upper airway,involving cessation or significant decreased airflow,with intermittent hypoxemia,frequent arousals from sleep and recurrent oxyhemoglobin desaturations that interfere with normal sleep patterns generating difficulty falling asleep,unrefreshing sleep and loud snoring. The relation between these two entities is known as "Syndrome Z",and there is no question about the impact of these risk factors on health and disease. This clinical condition presents a growing epidemic Worldwide,affecting approximately 60% of the general population with both MS and OSA due to the constant increase of body mass index in humans. This article presents evidence-based data that focuses on the direct relationship between MS and OSA.

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.

Correlation of obstructive sleep apnea hypopnea syndrome with metabolic syndrome in snorers

Though obstructive sleep apnea hypopnea syndrome（OSAHS） and metabolic syndrome（MS） are correlated;the contributing factors for the occurrence of MS in Chinese snorers remain largely undefined.We aimed to investigate the associated pathogenesis of coexistence of OSAHS and MS in Chinese snorers.A total of 144 Chinese habitual snorers were divided into 3 groups,the control group（simple snorers）（n = 36）,the mild OSAHS group（n= 52）and the moderate-to-severe OSAHS group（n = 56）.The incidence of MS in the moderate-to-severe OSAHS group（26.8%） was significantly higher than that in the control group（8.3%）,the mild OSAHS group（11.1%） and all the OSAHS patients（19.45%）（all P 〈 0.05）.Homeostatic model assessment（HOMA） index and proinsulin（PI） were negatively correlated with nocturnal meanSpO2 and miniSpO2.Meanwhile,nocturnal SpO2 were negatively correlated with body mass index,waist and neck circumferences and diastolic blood pressure,but positively correlated with total cholesterol and high-density lipoprotein cholesterol.The study indicated that in Chinese snorers,moderate-to-severe OSAHS was closely associated with MS via nocturnal hypoxemia.