Obstructive sleep apnea, inflammation, and the metabolic syndrome

Identification biomarkers in disease progression of obstructive sleep apnea from children serum based on WGCNA and Mfuzz

Obstructive sleep apnea (OSA) syndrome is a prevalent form of respiratory sleep disorder, with an increasing prevalence among children. The consequences of OSA include obesity, diabetes, cardiovascular disease, and neuropsychological diseases. Despite its pervasive impact, a significant proportion of individuals especially children remain unaware that they suffer from OSA. Consequently, there is an urgent need for an accessible diagnostic approach. In this study, we conducted a bioinformatic analysis to identify potential biomarkers from a proteomics dataset comprising serum samples from children with OSA in the progression stage. In the Gene Set Enrichment Analysis (GSEA), we observed that the complement and immune response pathways persisted throughout the development of OSA and could be detected in the early stages. Subsequent to soft clustering and WGCNA analysis, it was revealed that the Hippo pathway, including ITGAL and FERMT3, plays a role in mild OSA. The analysis revealed a significant alteration of the complement and coagulation pathways, including TFPI and MLB2, in moderate OSA. In severe OSA, there was an association between hypoxia and the extracellular matrix (ECM) receptor interaction and collagen binding. In summary, it can be posited that the systemic inflammation may persist throughout the progression of OSA. Furthermore, severe OSA is characterized by abnormal vascular endothelial function, which may be attributed to chronic hypoxia. Finally, four potential biomarkers (ITGAL, TFPI, TTR, ANTXR1) were identified based on LASSO regression, and a prediction model for OSA progression was constructed based on the biomarkers.

Links Between Obstructive Sleep Apnea and Myocardial Blood Flow Changes Impacting Adverse Cardiovascular Disease-related Outcomes

PURPOSE OF REVIEW

Recent studies have demonstrated an association between obstructive sleep apnea (OSA) and abnormal myocardial blood flow (MBF), myocardial flow reserve (MFR), and coronary microvascular dysfunction (CMD). Here, we review the evidence and describe the potential underlying mechanisms linking OSA to abnormal MBF. Examining relevant studies, we assess the impact of OSA-specific therapy, such as continuous positive airway pressure (CPAP), on MBF.

RECENT FINDINGS

Recent studies suggest an association between moderate to severe OSA and abnormal MBF/MFR. OSA promotes functional and structural abnormalities of the coronary microcirculation. OSA also promotes the uncoupling of MBF to cardiac work. In a handful of studies with small sample sizes, CPAP therapy improved MBF/MFR. Moderate to severe OSA is associated with abnormal MFR, suggesting an association with CMD. Evidence suggests that CPAP therapy improves MBF. Future studies must determine the clinical impact of improved MBF with CPAP.

All Obstructive Sleep Apnea Events Are Not Created Equal: The Relationship between Event-related Hypoxemia and Physiologic Response

Rationale: Obstructive sleep apnea (OSA) severity is typically assessed by the apnea-hypopnea index (AHI), a frequency-based metric that allocates equal weight to all respiratory events. However, more severe events may have a greater physiologic impact. Objectives: The purpose of this study was to determine whether the degree of event-related hypoxemia would be associated with the postevent physiologic response. Methods: Patients with OSA (AHI, ⩾5/h) from the multicenter Canadian Sleep and Circadian Network cohort were studied. Using mixed-effect linear regression, we examined associations between event-related hypoxic burden (HBev) assessed by the area under the event-related oxygen saturation recording with heart rate changes (ΔHRev), vasoconstriction (vasoconstriction burden [VCBev] assessed with photoplethysmography), and electroencephalographic responses (power ratio before and after events). Results: Polysomnographic recordings from 658 patients (median [interquartile range] age, 55.00 [45.00, 64.00] yr; AHI, 27.15 [14.90, 64.05] events/h; 42% female) were included in the analyses. HBev was associated with an increase in all physiologic responses after controlling for age, sex, body mass index, sleep stage, total sleep time, and study centers; for example, 1 standard deviation increase in HBev was associated with 0.21 [95% confidence interval, 0.2, 0.22], 0.08 [0.08, 0.09], and 0.22 [0.21, 0.23] standard deviation increases in ΔHRev, VCBev, and β-power ratio, respectively. Conclusions: Increased event-related hypoxic burden was associated with greater responses across a broad range of physiologic signals. Future metrics that incorporate information about the variability of these physiologic responses may have promise in providing a more nuanced assessment of OSA severity.

Obstructive sleep apnoea heterogeneity and cardiovascular disease

Obstructive sleep apnoea (OSA), characterized by recurrent periods of upper airway obstruction and intermittent hypoxaemia, is prevalent in patients with cardiovascular disease (CVD), and is therefore important to consider in the prevention and management of CVD. Observational studies indicate that OSA is a risk factor for incident hypertension, poorly controlled blood pressure, stroke, myocardial infarction, heart failure, cardiac arrhythmias, sudden cardiac death and all-cause death. However, clinical trials have not provided consistent evidence that treatment with continuous positive airway pressure (CPAP) improves cardiovascular outcomes. These overall null findings might be explained by limitations in trial design and low levels of adherence to CPAP. Studies have also been limited by the failure to consider OSA as a heterogeneous disorder that consists of multiple subtypes resulting from variable contributions from anatomical, physiological, inflammatory and obesity-related risk factors, and resulting in different physiological disturbances. Novel markers of sleep apnoea-associated hypoxic burden and cardiac autonomic response have emerged as predictors of OSA-related susceptibility to adverse health outcomes and treatment response. In this Review, we summarize our understanding of the shared risk factors and causal links between OSA and CVD and emerging knowledge on the heterogeneity of OSA. We discuss the varied mechanistic pathways that result in CVD that also vary across subgroups of OSA, as well as the potential role of new biomarkers for CVD risk stratification.

Pathophysiology and probable etiology of cerebral small vessel disease in vascular dementia and Alzheimer's disease

Vascular cognitive impairment and dementia (VCID) is commonly caused by vascular injuries in cerebral large and small vessels and is a key driver of age-related cognitive decline. Severe VCID includes post-stroke dementia, subcortical ischemic vascular dementia, multi-infarct dementia, and mixed dementia. While VCID is acknowledged as the second most common form of dementia after Alzheimer's disease (AD) accounting for 20% of dementia cases, VCID and AD frequently coexist. In VCID, cerebral small vessel disease (cSVD) often affects arterioles, capillaries, and venules, where arteriolosclerosis and cerebral amyloid angiopathy (CAA) are major pathologies. White matter hyperintensities, recent small subcortical infarcts, lacunes of presumed vascular origin, enlarged perivascular space, microbleeds, and brain atrophy are neuroimaging hallmarks of cSVD. The current primary approach to cSVD treatment is to control vascular risk factors such as hypertension, dyslipidemia, diabetes, and smoking. However, causal therapeutic strategies have not been established partly due to the heterogeneous pathogenesis of cSVD. In this review, we summarize the pathophysiology of cSVD and discuss the probable etiological pathways by focusing on hypoperfusion/hypoxia, blood-brain barriers (BBB) dysregulation, brain fluid drainage disturbances, and vascular inflammation to define potential diagnostic and therapeutic targets for cSVD.

Racial disparity in cardiovascular morbidity and mortality associated with obstructive sleep apnea: The sleep heart health study

BACKGROUND

African Americans (AA) have higher prevalence of cardiovascular diseases (CVD) and obstructive sleep apnea (OSA) compared to Whites. Previous research demonstrated increased risk of cardiovascular complications from OSA but there is paucity of data about any interaction of race on this effect. Sleep Heart Health Study (SHHS) is a multi-center cohort study that was done to determine the cardiovascular consequences of OSA. Using this data, we assessed the racial disparity of various CVD incidence and mortality between Whites and AA associated with OSA.

METHODS

We analyzed data from 5692 participants. Logistic regressions were done to compare the incidence of all CVD and stroke between White and AA. Cumulative death risk from all causes over 13 years were assessed by Cox's proportional hazard model. All models were adjusted for age, BMI, gender, education, hypertension, diabetes, smoking, total sleep time and OSA.

RESULTS

Compared to Whites, AA had higher adjusted odds of developing any CVD (OR = 1.6, 95% CI = 1.19-2.15) and stroke (OR = 1.71, 95 CI = 1.13-2.61). OSA remains an independent risk factor for CVD (OR = 1.15, 96% CI = 1.01-1.47) and stroke (OR = 1.36, 95% CI = 1.04-2.16) after adjusting for race and other covariates. The cumulative adjusted mortality risk was 1.24 times higher in AA than White (95% CI = 1.02-1.51) during this follow up period. Subjects with OSA in highest AHI quartile had 1.35 times (95% CI = 1.13-1.63) higher mortality compared to lowest quartile.

CONCLUSION

AA race and untreated OSA are independent predictors for new onset CVD, stroke and higher all-cause mortality, after adjusting for cardiovascular risk factors.

Association between obstructive sleep apnea syndrome and bone mineral density in adult orthodontic populations

OBJECTIVE

To determine the association between obstructive sleep apnea syndrome (OSAS) and predicted bone mineral density (BMD) in adults presenting for orthodontic treatment.

METHODS

This retrospective cross-sectional study included 38 adults divided into OSAS and non-OSAS groups. Using pre-treatment CBCT images, radiographic density (RD) of left and right lateral regions of the 1st cervical vertebrae and dens of the 2nd cervical vertebrae were measured as an indicator for BMD.

RESULTS

When controlling for age, sex, and BMI, the mean RD was significantly lower in the OSAS group compared to the non-OSAS group (left CV1: 36.69 ± 84.50 vs. 81.67 ± 93.25 Hounsfield Units [HU], respectively, p = 0.031; right CV1: 30.59 ± 81.18 vs. 74.26 ± 91.81 HU, p = 0.045; dens: 159.25 ± 115.96 vs. 223.94 ± 106.09 HU, p = 0.038).

CONCLUSION

Adults with OSAS have lower values for predicted BMD than those without OSAS.

Association between sleep-disordered breathing and periodontal diseases: A systematic review protocol

Background

Sleep-disordered breathing (SDB) is a chronic sleep-related breathing disorder, considered associated with increased risk of cardiovascular disorders, metabolic disorders, cognitive dysfunction and behavior changes. Periodontal diseases are chronic infectious diseases that are also believed to be associated with cardiovascular diseases, metabolic syndrome and cognitive dysfunction. Several studies have indicated that SDB may be associated with periodontal diseases through certain mechanisms such as inflammation response, oxidative stress and oral dryness. The aim of this systematic review is to explore the association between SDB and periodontal diseases in an integrated approach.

Materials and Methods

This systematic review will include cohort studies, cross-sectional studies and case-control studies that are identified by electronic and manual searches. Electronic searches will be conducted in the following databases: PubMed, Embase, Scopus and Web of Science. Our search will cover articles published from inception of databases to March 2022 without restrictions in language and settings. Pre-determined eligibility criteria include: participants (participants without a history of respiratory diseases, history of periodontal treatment within the past 6 months and history of medication that is known to influence SDB or periodontal diseases); exposure (participants who have been diagnosed with SDB or at high-risk for SDB); comparison (participants without SDB); and outcome (periodontal parameters, such as probing depth, clinical attachment level, bleeding on probing, radiographic bone loss). Two authors will perform study screening and data extraction independently and in duplicate. All discrepancies will be solved by discussion. The methodological quality of included studies will be assessed using the Newcastle-Ottawa Scale.

Discussion

This systematic review will summarize the existing evidence on the association between SDB and periodontal diseases, a topic of controversy and clinical significance. Its findings can provide evidence for the development of relevant prevention and treatment strategies. The results will be disseminated through peer-reviewed journals.

Systematic review registration

https://www.crd.york.ac.uk/PROSPERO/, identifier: CRD42022313024. Registered on March 28th 2022.

Interactions between Obstructive Sleep Apnea Syndrome Severity, Obesity, Sex Difference and Attention-Deficit/Hyperactivity Disorder on Health-Related Quality of Life: A Non-Interventional Prospective Observational Study

Obstructive sleep apnea syndrome (OSAS) severity, obesity, sex difference, and attention-deficit/hyperactivity disorder (ADHD) had a complex impact on health-related quality of life (HRQoL). However, the interactive effects among these features on HRQoL remained to be clarified. This study aimed to investigate the individual and interactive associations between the four characteristics of interest and HRQoL as determined by 36-Item Short Form Health Survey, Pittsburgh Sleep Quality Index (PSQI), and Epworth Sleepiness Scale (ESS). This non-interventional, prospective, observational study enrolled a total of 132 patients with suspected OSAS for analysis. While OSAS severity and ADHD detected by adult ADHD Self-Report Scale, termed as screened ADHD, interact with each other, all the four studied features were individually associated with HRQoL. After adjusting for potential physiological and polysomnographic confounders, screened ADHD was independently correlated with PSQI > 5 (OR = 4.126, 95% CI, 1.490−11.424), mental component score < 50 (OR = 5.873, 95% CI, 2.262−15.251) and ESS > 10 (OR = 3.648, 95% CI, 1.738−7.657). Our results show that ADHD detection is necessary and should be incorporated into clinical practice for OSAS management.

Multiple Sclerosis and related disorders

Multiple Sclerosis (MS) is a common neuroinflammatory disorder which is associated with disabling clinical consequences. The MS disease process may involve neural centers implicated in the control of breathing, leading to ventilatory disturbances during both wakefulness and sleep. In this chapter, a brief overview of MS disease mechanisms and clinical sequelae including sleep disorders is provided. The chapter then focuses on obstructive sleep apnea-hypopnea (OSAH) which is the most prevalent respiratory control abnormality encountered in ambulatory MS patients. The diagnosis, prevalence, and clinical consequences as well as data on effects of OSAH treatment in MS patients are discussed, including the impact on the disabling symptom of fatigue and other clinical sequelae. We also review pathophysiologic mechanisms contributing to OSAH in MS, and in turn mechanisms by which OSAH may impact on the MS disease process, resulting in a bidirectional relationship between these two conditions. We then discuss central sleep apnea, other respiratory control disturbances, and the pathogenesis and management of respiratory muscle weakness and chronic hypoventilation in MS. We also provide a brief overview of Neuromyelitis Optica Spectrum Disorders and review current data on respiratory control disturbances and sleep-disordered breathing in that condition.

Potential impact of pediatric obstructive sleep apnea on mandibular cortical width dimensions

STUDY OBJECTIVES

To analyze differences in mandibular cortical width (MCW) among children diagnosed with obstructive sleep apnea (OSA) or at high- or low-risk for OSA.

METHODS

A total of 161 children were assessed: 60 children with polysomnographically diagnosed OSA, 56 children presenting symptoms suggestive of high-risk for OSA, and 45 children at low risk for OSA. Children at high- and low-risk for OSA were evaluated through the Pediatric Sleep Questionnaire. MCW was calculated using ImageJ software from panoramic radiograph images available from all participants. Differences between MCW measurements in the 3 groups were evaluated using analysis of covariance and Bonferroni post-hoc tests, with age as a covariate. The association between MCW and specific cephalometric variables was assessed through regression analysis.

RESULTS

The participants' mean age was 9.6 ± 3.1 years (59% male and 41% female). The mean body mass index z-score was 0.62 ± 1.3. The polysomnographically diagnosed OSA group presented smaller MCW than the group at low-risk for OSA (mean difference = -0.385 mm, P = .001), but no difference with the group at high-risk for OSA (polysomnographically diagnosed OSA vs high-risk OSA: P = .085). In addition, the MCW in the group at high-risk for the OSA was significantly smaller than the group at low-risk for the OSA (mean difference = -0.301 mm, P = .014). The cephalometric variables (Sella-Nasion-A point angle (SNA) and Frankfort - Mandibular Plane angle (FMA)) explained only 8% of the variance in MCW.

CONCLUSIONS

Reductions in MCW appear to be present among children with OSA or those at high-risk for OSA, suggesting potential interactions between mandibular bone development and/or homeostasis and pediatric OSA.

CITATION

Fernandes Fagundes NC, d'Apuzzo F, Perillo L, et al. Potential impact of pediatric obstructive sleep apnea on mandibular cortical width dimensions. J Clin Sleep Med. 2021;17(8):1627-1634.

Higher refined cereal grain intake is positively associated with apnoea-hypopnoea index in patients with obstructive sleep apnoea

BACKGROUND

Given that obesity is a well-known risk factor for obstructive sleep apnoea (OSA) development, dietary habits may be involved in its pathogenesis. However, little is known about the associations between dietary habits and OSA severity. The present study aimed to investigate possible associations between cereal grain intake and apnoea/hypopnoea indices in OSA patients.

METHODS

This was a cross-sectional study of 269 patients (21-70 years; 73.2% males) diagnosed with OSA via an attended in-hospital polysomnography. Information on demographics, medical history, anthropometric indices and lifestyle habits were collected at enrolment. Biochemical measurements were performed in all study participants using standard procedures. Cereal grain consumption was evaluated using a validated food frequency questionnaire. Severe OSA was defined as having an apnoea-hypopnoea index ≥30 events h^-1 .

RESULTS

In adjusted analyses, higher intake of refined cereal grains was positively associated with apnoea-hypopnoea index (p_trend = 0.022), after adjusting for age, sex, socio-economic parameters, smoking habits, waist circumference, physical activity level, adequacy of night-time sleep, diet's quality as assessed by a relevant score, insulin resistance and C-reactive protein levels). Multiple logistic regression analysis also showed that energy-adjusted refined grain intake was associated with increased likelihood of severe OSA (odds ratio = 1.56, 95% confidence interval = 1.06-2.30). Νo association between apnoea/hypopnoea indices and non-refined grain intake was observed in this study.

CONCLUSIONS

The findings show that obstructive sleep apnoea (OSA) is associated with cereal grain intake and suggest that a higher intake of refined cereal grains may be a risk factor for OSA severity.

Chronobiology and the case for sleep health interventions in the community

Our sleep-wake cycle is determined by the interaction between our homeostatic sleep drive and circadian rhythm. Each of us has a personalised biological rhythm or chronotype that determines the optimal time to fall asleep and wake up. Chronic sleep deprivation has been linked to the development of several physical and mental health disorders, as well as accidents and occupational errors. Around the world, growing recognition of the importance of sleep has led to the adoption of practices that promote sleep health. Given that Singaporeans were consistently found to be one of the most sleep-deprived populations in the world, we believe that there is an urgent need to pursue the introduction of community-based sleep health interventions here. This includes sleep education and promotion of sleep hygiene, adopting practices to reduce social jetlag and improve sleep health, and enhancing screening and treatment of sleep disorders.

Maternal Sleep-Disordered Breathing in Pregnancy and Increased Nocturnal Glucose Levels in Women with Gestational Diabetes Mellitus

BACKGROUND

Women with hyperglycemia during pregnancy are at high risk for adverse perinatal outcomes. Maternal sleep-disordered breathing (SDB) during pregnancy is common and is a risk factor for gestational diabetes mellitus (GDM). However, the relationship between SDB severity and glucose control is unknown.

RESEARCH QUESTION

Is there an association between SDB severity and glucose levels as assessed by continuous glucose monitoring in GDM?

STUDY DESIGN AND METHODS

Women with GDM underwent sleep recordings and 72-hour continuous glucose monitoring. Linear mixed models were used to estimate the association of the apnea-hypopnea index (AHI), rapid eye movement (REM)-AHI, and non-REM-AHI with mean glucose levels during nighttime (two periods: 11 pm to 3 am and 3 am to 6 am), daytime (8 am to 9 pm), and 24-hours. Models were adjusted for BMI and antihyperglycemic medications.

RESULTS

In 65 participants who were 35 ± 5 (mean ± SD) years of age with BMI of 33 ± 7 kg/m², 31% were undergoing insulin and/or metformin therapy. A ten-unit increase in AHI was associated with elevated nocturnal glucose levels (11 pm to 3 am: 0.20 mmol/L [95% CI, 0.04-0.40]) with persistent elevations into the morning (8 am: 0.26 mmol/L [95% CI, 0.08-0.4]) when adjusted for BMI and medications. REM-AHI was also associated with higher nocturnal and morning glucose levels, whereas non-REM was not. AHI was not associated with either mean daytime or 24-hour glucose levels.

INTERPRETATION

Greater severity of SDB was associated with higher nocturnal and morning glucose levels in women with GDM.

Association between non-alcoholic fatty liver disease and obstructive sleep apnea

BACKGROUND

Non-alcoholic fatty liver disease (NAFLD) is an emerging liver disease and currently the most common cause of incidental abnormal liver tests. The pathogenesis of NAFLD is multifactorial and many mechanisms that cause fatty liver infiltration, inflammation, oxidative stress and progressive fibrosis have been proposed. Obstructive sleep apnea (OSA) may be linked with the pathogenesis and the severity of NAFLD.

AIM

To study the association between NAFLD and OSA considering also the efficacy of continuous positive airway pressure (CPAP) treatment.

METHODS

A PubMed search was conducted using the terms “non-alcoholic fatty liver disease AND (obstructive sleep apnea OR obstructive sleep disorders OR sleep apnea)”. Research was limited to title/abstract of articles published in English in the last 5 years; animal and child studies, case reports, commentaries, letters, editorials and meeting abstracts were not considered. Data were extracted on a standardized data collection table which included: First author, publication year, country, study design, number of patients involved, diagnosis and severity of OSA, diagnosis of NAFLD, patient characteristics, results of the study.

RESULTS

In total, 132 articles were initially retrieved on PubMed search and 77 in the last five years. After removal of irrelevant studies, 13 articles were included in the qualitative analysis. There was a total of 2753 participants across all the studies with a mean age between 42 and 58 years. The proportion of males ranged from 21% to 87.9% and the mean body mass index ranged from 24.0 to 49.9 kg/m². The results of this review showed an increased prevalence of NAFLD in patients with diagnosis of OSA, even in the absence of coexisting comorbidities such as obesity or metabolic syndrome. Furthermore, the severity of NAFLD is associated with the increase in OSA severity. Effective CPAP treatment, although not always decisive, may stabilize or slow NAFLD progression with benefits on metabolic and cardiovascular functions.

CONCLUSION

In NAFLD patients, although asymptomatic, it is recommended to systematically perform polysomnography in order to early and better treat them before the development of potentially life threatening systemic dysfunctions.

Witnessed sleep apneas together with elevated plasma glucose are predictors of COPD exacerbations

Objective

Sleep apnea and elevated plasma glucose associates with inflammation which associates with the risk of COPD exacerbations. We investigated the risk of exacerbations in individuals with COPD, witnessed sleep apneas, and elevated plasma glucose.

Methods

From the Copenhagen City Heart Study cohort, we identified 564 individuals with COPD (forced expiratory volume in 1 sec divided by forced vital capacity, FEV₁/FVC<0.70), no asthma, above 40 years of age, and more than 10 pack-years of smoking history, with information on witnessed apneas and levels of plasma glucose. We prospectively recorded hospital admissions with COPD exacerbations during maximum available follow-up (26.3 years; mean 10.7 years). Cox-regression analyses were used to analyze the risk of COPD exacerbations.

Results

We identified 74 (13%) individuals with sleep apnea without elevated plasma glucose, 70 (12%) had elevated plasma glucose (above 6.9 mM (>125 mg/dL)) without sleep apnea and 11 individuals had the presence of both conditions. In univariable analysis, witnessed apneas together with elevated plasma glucose had a high risk of exacerbations, hazard ratio (HR) = 5.81 (2.34–14.4, p = 0.0001) compared to those without sleep apnea and without elevated plasma glucose. Multivariable analysis, adjusting for several risk factors of exacerbations, showed a similar result, HR = 3.45 (1.13–10.5, p = 0.03). Both presence of sleep apnea without elevated plasma glucose and the presence of elevated plasma glucose without sleep apnea showed no associations with the risk of exacerbations.

Conclusions

Witnessed sleep apneas in COPD are associated with increased risk of exacerbations, but only among those with elevated plasma glucose.

Examination of the Relationship Between Metabolic Syndrome and Obstructive Sleep Apnea in Iranian Patients with Type 2 Diabetes: A Case-Control Study

INTRODUCTION

Obstructive sleep apnea (OSA) is a common risk factor for metabolic syndrome (MS) that increases the chance of cardiovascular disease, stroke, and mortality. Many studies have been conducted on this matter, but the results are still conflicting. The aim of the present study was to examine the relationship between metabolic syndrome (MS) and obstructive sleep apnea (OSA) in Iranian patients with type 2 diabetes (T2D).

PATIENTS AND METHODS

This matched case-control study was conducted with 190 patients with T2D in Sanandaj, Iran. The data were selected using the demographic questionnaire, clinical and anthropometric measures, the Berlin Questionnaire (BQ), and the National Cholesterol Education Program's Adult Treatment Panel III (NCEP-ATP III). Participants were divided into two groups of high risk of OSA (experimental) and low risk of OSA (control). The data were analyzed using Stata, version 14.

RESULTS

The frequency of MS was higher in the OSA group than the control group (81.1% vs 70.5%), but the group difference was not statistically significant (p=0.127). The results of crude and age-sex adjusted logistic regression analysis revealed no significant association between OSA and the other variables under study (P>0.05). Sensitivity analysis and external adjustment for BMI showed no significant relationship between OSA and the other variables under study (P=0.319).

CONCLUSION

In the present study, no significant association was found between metabolic syndrome (MS) and obstructive sleep apnea (OSA) in patients with T2D; therefore, more studies should be conducted on this subject.

Impact of obstructive sleep apnea on silent cerebral small vessel disease: a systematic review and meta-analysis

BACKGROUND

Cerebral small vessel disease (CSVD) is a well-known cause of vascular dementia, a leading medical morbidity in the aging population. Obstructive sleep apnea (OSA) has been validated as a cardiovascular risk factor. However, the relationship between these two clinical syndromes is not well established. We aimed to assess the association between OSA and CSVD.

METHODS

Databases were searched from inception through May 2019. Studies that reported incidence or odd ratios of CSVD in patients with OSA were included. Effect estimates from the individual studies were extracted and combined using random-effect, generic inverse variance method of DerSimonian and Laird.

RESULTS

A total of 14 observational studies comprising of 4335 patients were included into the analysis. Compared to patients without OSA, patients with OSA were significantly associated with CSVD magnetic resonance imaging (MRI) findings of white matter hyperintensity (WMH) and asymptomatic lacunar infarction (ALI) with a pooled OR of 2.31 (95% confidence interval [CI], 1.46-3.66, I² = 79%) and 1.78 (95% CI, 1.06-3.01, I² = 41%), respectively. However, there was no significant association between OSA and findings of cerebral microbleeds (CMBs), with a pooled odds ratio (OR) of 2.15 (95% CI, 0.64-7.29, I² = 55%).

CONCLUSIONS

Our study demonstrated the association between OSA and CSVD MRI findings of white matter hyperintensity (WMH) and asymptomatic lacunar infarction (ALI) when compared to patients without OSA. The absence of an association of CMBs findings with OSA could be due either by a lower sensitivity of neuroimaging techniques utilized to detect CMBs or a potentially different pathogenesis of CMBs.

Protocol of the SOMNIA project: an observational study to create a neurophysiological database for advanced clinical sleep monitoring

INTRODUCTION

Polysomnography (PSG) is the primary tool for sleep monitoring and the diagnosis of sleep disorders. Recent advances in signal analysis make it possible to reveal more information from this rich data source. Furthermore, many innovative sleep monitoring techniques are being developed that are less obtrusive, easier to use over long time periods and in the home situation. Here, we describe the methods of the Sleep and Obstructive Sleep Apnoea Monitoring with Non-Invasive Applications (SOMNIA) project, yielding a database combining clinical PSG with advanced unobtrusive sleep monitoring modalities in a large cohort of patients with various sleep disorders. The SOMNIA database will facilitate the validation and assessment of the diagnostic value of the new techniques, as well as the development of additional indices and biomarkers derived from new and/or traditional sleep monitoring methods.

METHODS AND ANALYSIS

We aim to include at least 2100 subjects (both adults and children) with a variety of sleep disorders who undergo a PSG as part of standard clinical care in a dedicated sleep centre. Full-video PSG will be performed according to the standards of the American Academy of Sleep Medicine. Each recording will be supplemented with one or more new monitoring systems, including wrist-worn photoplethysmography and actigraphy, pressure sensing mattresses, multimicrophone recording of respiratory sounds including snoring, suprasternal pressure monitoring and multielectrode electromyography of the diaphragm.

ETHICS AND DISSEMINATION

The study was reviewed by the medical ethical committee of the Maxima Medical Center (Eindhoven, the Netherlands, File no: N16.074). All subjects provide informed consent before participation.The SOMNIA database is built to facilitate future research in sleep medicine. Data from the completed SOMNIA database will be made available for collaboration with researchers outside the institute.

Resolution of Symptomatic Obstructive Sleep Apnea Not Impacted by Preoperative Body Mass Index, Choice of Operation Between Sleeve Gastrectomy and Roux-en-Y Gastric Bypass Surgery, or Severity

BACKGROUND

Obstructive sleep apnea (OSA) is a serious obesity-associated disorder that causes significant short- and long-term medical consequences.

OBJECTIVE

The objective of this study is to compare the 6-month and 1-year postoperative symptomatic OSA remission rates of patients undergoing bariatric surgery based on their preoperative body mass index (BMI) stratification, type of bariatric operation-sleeve gastrectomy (SG) or Roux-en-Y gastric bypass (RYGB)-and OSA severity.

METHODS

We retrospectively analyzed 297 obese patients with a diagnosis of OSA who had undergone either SG or RYGB between 2011 and 2015.

RESULTS

The overall 6-month symptomatic OSA remission rate for patients (n = 255) was 74.5%. At 6 months, patients with a preoperative BMI of 30-34.9 kg/m² (class I), 35-39.9 kg/m² (class II), and 40+ kg/m² (class III) had 100, 70.0, and 75.0% (p = 0.2164) remission rates, respectively. The 6-month remission rates for SG and RYGB were 75.3 and 70.8% (p = 0.5165), respectively. The overall 1-year symptomatic OSA remission rate for patients (n = 162) was 87.1%. At 1 year, class I, II, and III patients had 100, 85.7, and 87.5% (p = 0.5740) remission rates, respectively. The 1-year remission rates for SG and RYGB were 89.2 and 81.2% (p = 0.2189), respectively. A sub-analysis (n = 69) based on preoperative OSA severity levels did not affect the remission outcome at either the 6-month (p = 0.3670) or 1-year (p = 0.3004) follow-up.

CONCLUSION

Most obese patients experience symptomatic remission of their OSA after bariatric surgery, regardless of their preoperative BMI, choice of operation, or OSA severity.

Oral Health and Oral Health-Related Quality of Life in Children With Obstructive Sleep Apnea

STUDY OBJECTIVES

This aim of this study was to evaluate oral health and oral health-related quality of life (OHRQoL) in children with obstructive sleep apnea (OSA).

METHODS

This cross-sectional study involved 31 children who had baseline polysomnography studies and in whom a diagnosis of OSA was made by a sleep physician. They were evaluated against 36 control patients who, based on parent responses to the Pediatric Sleep Questionnaire, were at very low risk for having sleep problems. The mean age of the cohort was 12.3 ± 2.7 years. The oral health status was examined clinically and recorded using caries and periodontal indices. OHRQoL was measured using the Child Oral Health Impact Profile (COHIP) questionnaires.

RESULTS

Children with OSA had significantly worsened oral health compared to control patients as evidenced by more caries (15.2 and 3.2, respectively; P < .001) and more periodontitis. Periodontitis severity was measured by the presence of bleeding on probing, (87% versus 30%, P < .001) and higher number of sites with abnormally deep periodontal probing depths (2.7 versus 0.3, P < .001). The COHIP scores were significantly higher among children with OSA compared to control patients, (29.7 versus 11.8, P < .001) consistent with poorer OHRQoL.

CONCLUSIONS

This study suggests that in children OSA may have a significant association with poorer oral health when compared to control patients without sleep problems, and that their oral health status may have a negative effect on their quality of life. Increased awareness regarding the oral health effects of sleep-disordered breathing in the medical and dental community is needed.

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.

Effect of semi-rapid maxillary expansion in children with obstructive sleep apnea syndrome: 5-month follow-up study

BACKGROUND

The purpose of this study was to investigate the effect of semi-rapid maxillary expansion (SRME) orthodontic treatment on biomarkers and respiratory parameters in children with obstructive sleep apnea syndrome (OSAS) and maxillary transverse deficiency.

METHODS

Thirty children with OSAS were included in this study. Fifteen children were enrolled as control, and 15 children were subjected to SRME orthodontic treatment method for 5 months. Beside respiratory parameters, pharyngeal area, dental arch, and postero-anterior widths and the levels of OSAS biomarkers in serum and urine were measured.

RESULTS

Pharyngeal airway space, dental arch, and postero-anterior widths were increased after SRME treatment. Sleep tests showed a decrease in the apnea-hypopnea index (AHI) after 5-month control/treatment duration. Serum kallikrein (KLK)1 levels decreased significantly in the treatment group. There was a significant increase in serum orosomucoid (ORM)2 levels and a decrease in urine perlecan levels in the control group after a 5-month follow-up. A significant negative correlation between serum ORM2, perlecan, gelsolin, and KLK1 levels and intercanin width, as well as between serum ORM2 and KLK1 levels and intermolar width, was observed.

CONCLUSIONS

SRME treatment can be considered as a useful approach in children with OSAS. A further investigation of OSAS-related biomarkers and their relationship with sleep and orthodontic parameters is needed for providing easier and reliable modulatory strategies in the treatment of OSAS.

Intermittent hypoxia causes histological kidney damage and increases growth factor expression in a mouse model of obstructive sleep apnea

Epidemiological studies demonstrate an association between obstructive sleep apnea (OSA) and accelerated loss of kidney function. It is unclear whether the decline in function is due to OSA per se or to other confounding factors such as obesity. In addition, the structural kidney abnormalities associated with OSA are unclear. The objective of this study was to determine whether intermittent hypoxia (IH), a key pathological feature of OSA, induces renal histopathological damage using a mouse model. Ten 8-week old wild-type male CB57BL/6 mice were randomly assigned to receive either IH or intermittent air (IA) for 60 days. After euthanasia, one kidney per animal was paraformaldehyde-fixed and then sectioned for histopathological and immunohistochemical analysis. Measurements of glomerular hypertrophy and mesangial matrix expansion were made in periodic acid–Schiff stained kidney sections, while glomerular transforming growth factor-β1 (TGF-β1), connective tissue growth factor (CTGF) and vascular endothelial growth factor-A (VEGF-A) proteins were semi-quantified by immunohistochemistry. The antigen-antibody reaction was detected by 3,3′-diaminobenzidine chromogen where the color intensity semi-quantified glomerular protein expression. To enhance the accuracy of protein semi-quantification, the percentage of only highly-positive staining was used for analysis. Levels of TGF-β, CTGF and VEGF-A proteins in the kidney cortex were further quantified by western blotting. Cellular apoptosis was also investigated by measuring cortical antiapoptotic B-cell lymphoma 2 (Bcl-2) and apoptotic Bcl-2-associated X (Bax) proteins by western blotting. Further investigation of cellular apoptosis was carried out by fluorometric terminal deoxynucleotidyl transferase (TdT) dUTP Nick-End Labeling (TUNEL) staining. Finally, the levels of serum creatinine and 24-hour urinary albumin were measured as a general index of renal function. Our results indicate that mice exposed to IH have an increased glomerular area (by 1.13 fold, p< 0.001) and expansion of mesangial matrix (by 1.8 fold, p< 0.01). Moreover, the glomerular expressions of TGF-β1, CTGF and VEGF-A proteins were 2.7, 2.2 and 3.8-fold higher in mice exposed to IH (p< 0.05 for all). Furthermore, western blotting protein analysis demonstrates that IH-exposed mice express higher levels of TGF-β1, CTGF and VEGF-A proteins by 1.9, 4.0 and 1.6-fold (p< 0.05 for all) respectively. Renal cellular apoptosis was greater in the IH group as shown by an increased cortical Bax/Bcl-2 protein ratio (p< 0.01) and higher fluorometric TUNEL staining (p< 0.001). Finally, 24-hr urinary albumin levels were higher in mice exposed to IH (43.4 μg vs 9.7 μg, p< 0.01), while there were no differences in serum creatinine levels between the two groups. We conclude that IH causes kidney injury that is accompanied by glomerular hypertrophy, mesangial matrix expansion, increased expression of glomerular growth factors and an increased cellular apoptosis.

A low-carbohydrate survey: Evidence for sustainable metabolic syndrome reversal

Background: Metabolic syndrome has become a significant problem, with the American Diabetes Association estimating the cost of diabetes and pre-diabetes in the United States alone to be $322 billion per year. Numerous clinical trials have demonstrated the efficacy of low-carbohydrate diets in reversing metabolic syndrome and its associated disorders.Aim: This study was designed to examine how voluntary adherents to a low-carbohydrate diet rate its effectiveness and sustainability using an online survey.Setting and methods: The 57-question survey was administered online and shared internationally via social media and ‘low-carb’ communities. Where appropriate, chi-squared tests and paired t-tests were used to analyse the responses.Results: There were 1580 respondents. The majority of respondents had consumed less than 100 g of carbohydrates per day for over a year, typically for reasons of weight loss or disease management. There was a reported decrease in waist circumference and weight with a simultaneous decrease in hunger and increase in energy level. Of those who provided laboratory values, the majority saw improvements in their HbA1c, blood glucose measurements, and lipid panel results. There was a reduction in usage of various medications, and 25% reported medication cost savings, with average monthly savings of $288 for those respondents. In particular, the usage of pain relievers and anti-inflammatories dropped with a simultaneous decreased rating of pain and increase in mobility.Conclusion: We conclude that low-carbohydrate diets are a sustainable method of metabolic syndrome reversal in a community setting.

A Preliminary Investigation of the Association of Sleep With Inflammation and Oxidative Stress Biomarkers and Functional Outcomes After Stroke Rehabilitation

This study examined the association of sleep with inflammation and oxidative stress biomarkers, and with functional outcomes, after stroke rehabilitation. The rehabilitation effects on biomarkers and functional outcomes were also evaluated. Twenty subacute stroke survivors received 4 weeks of upper limb rehabilitation. Baseline inflammatory (i.e., soluble intercellular adhesion molecule-1, sICAM-1) and oxidative stress biomarkers (i.e., glutathione peroxidase, GPx and malondialdehyde, MDA) were assessed, as were sleep outcomes. Positive correlations were observed between baseline level of sICAM-1 and number of awakenings at post-treatment (ρ = 0.51, p < 0.05) as well as between baseline level of MDA and post-performance time of the Wolf Motor Function Test (WMFT-time) (ρ = 0.46, p < 0.05). In addition, MDA levels were significantly decreased, and functional outcomes of the modified Rankin Scale (mRS), functional ability scale of the WMFT, and Stroke Impact Scale (SIS-total, and SIS-physical function) were improved after the rehabilitation. This pilot study emphasizes the relationship among biomarkers, sleep, and functional outcomes after stroke rehabilitation. Oxidative stress markers may be useful predictors of functional outcomes in subacute stroke survivors.

Association between sleep apnea and low bone mass in adults: a systematic review and meta-analysis

We performed a systematic review of the literature to assess the association between sleep apnea and bone metabolism diseases including osteoporosis in adult population. Results from clinical trials suggest that the association between sleep apnea and low bone mass in adults is possible.

INTRODUCTION

This study aimed to synthesize existing evidence on the potential association between sleep apnea and low bone mass in adults.

METHODS

Electronic searches of five databases were performed. The inclusion criteria consisted of studies in humans that assessed potential associations between sleep apnea and bone metabolic diseases in an adult population. For diagnosis of sleep apnea overnight polysomnography, home polygraphy, or validated records from healthcare databases were considered. Reduced bone density, osteoporosis, serum/urinary levels for markers of bone formation and resorption, or risk of fractures caused without history of trauma were considered indicators of low bone mass. A random-effects model meta-analysis was applied when possible.

RESULTS

Of the 963 relevant references, 12 studies met our inclusion criteria and were assessed to be of medium to low bias. Nine out of 12 studies reported an association between sleep apnea and low bone mass (increased bone resorption markers, reduced bone density, and higher risk of osteoporosis). Two studies did not report a significant association, whereas one study reported an increase of bone density in sleep apnea patients compared to non-sleep apnea patients. Meta-analysis of 2 studies (n = 112,258 patients) showed that sleep apnea was a significant risk factor for osteoporosis (odds ratio (OR), 1.92; 95%CI, 1.24 to 2.97; I² = 66%); females only had an OR of 2.56 (95% CI, 1.96 to 3.34; I² = 0%) while the OR in males was 2.03 (95% CI, 1.24 to 3.35; I² = 38%).

CONCLUSIONS

An association between sleep apnea and low bone mass in adults is plausible, but supporting evidence has a risk of bias and is inconsistent.

Effect of modern surgical treatment on the inflammatory/anti-inflammatory balance in patients with obstructive sleep apnoea

OBJECTIVE

To investigate the inflammatory/anti-inflammatory cytokine balance - T helper 1/T helper 2 ratios - in obstructive sleep apnoea patients, before and after treatment.

METHODS

Twenty-eight patients received continuous positive airway pressure treatment and 29 patients who could not tolerate continuous positive airway pressure were scheduled for surgery. Serum levels of interleukins 2, 4 and 10, tumour necrosis factor-alpha, and interferon gamma were analysed by enzyme-linked immunosorbent assays before and three months after treatment.

RESULTS

The success rate of surgical treatment was 65.5 per cent. Mean compliance for the continuous positive airway pressure group was 40.9 per cent. The apnoea/hypopnoea index significantly decreased in both groups after treatment (p < 0.001). The interferon gamma/interleukin-4 ratio decreased following surgical treatment (p = 0.014), and the interleukin-2/interleukin-4 ratio decreased after treatment in 57 patients in the overall cohort (p = 0.032).

CONCLUSION

After treatment for obstructive sleep apnoea, some ratios reflecting T helper 1/T helper 2 cytokine balance favoured the T helper 2 direction, suggesting a shift to an anti-inflammatory state. Successful surgery and better continuous positive airway pressure compliance can help ameliorate inflammation in obstructive sleep apnoea patients, which may reduce associated morbidities.

Is Obstructive Sleep Apnoea Related to Neuropsychological Function in Healthy Older Adults? A Systematic Review and Meta-Analysis

Previous systematic reviews and meta-analyses have identified cognitive deficits in adults with obstructive sleep apnoea (OSA). However, quantitative analysis of the association between OSA and neuropsychological performance has not been conducted specifically in older adults, for whom there is a greater risk of cognitive decline. We searched Medline, Embase and PsycINFO through August 2016 for studies describing associations between OSA and neuropsychological outcomes in people aged>50 years. Meta-analyses were performed on these studies for overall cognition and within cognitive domains. Subgroup analyses were performed taking into account risk of bias and moderating differences in study design. 13 studies met eligibility criteria for analysis. A small negative association was found between OSA and all neuropsychological outcomes combined, g=0.18(95% CI 0.04-0.32), and in memory and processing speed domains. Small case-control studies from sleep clinic populations observed the greatest associations, while larger cohort studies from community samples illustrated no association. Analysis accounting for publication bias resulted in a null overall association, g=0.02 (95%CI -0.12 to 0.16). Associations between OSA and cognition in later life are highly variable and the findings differ based on the type and setting of study. It appears some older adults may be at risk of cognitive impairments attributable to OSA; however, the risk of bias renders the evidence inconclusive. High quality research is warranted in clinically diagnosed OSA patients as well as those already experiencing neuropsychological impairment and who may be regarded at higher risk of further cognitive decline.

Psoriasis is associated with risk of obstructive sleep apnea independently from metabolic parameters and other comorbidities: a large hospital-based case-control study

PURPOSE

Obstructive sleep apnea (OSA) represents a breathing disorder during sleep with significant health consequences. Few studies have examined the prevalence of OSA in psoriatic patients and whether OSA may be associated with psoriasis risk. We aimed to explore: (1) the inverse relationship, that is whether psoriasis might represent an independent predictor of OSA and its severity considering important predisposing factors and (2) the psoriatic phenotype related to severe OSA.

METHODS

In a large hospital-based case-control study, we examined a total of 253 patients with OSA and a control group of 104 subjects without OSA, who underwent full nocturnal polysomnography and dermatologic examination.

RESULTS

The prevalence of psoriasis was significantly greater in OSA patients than in controls (p = 0.03). Psoriasis was associated with OSA risk (p = 0.04) but not severity of OSA, sleepiness severity or sleep efficiency, independently from age, gender, anthropometric features, and significant comorbidities. The phenotype of a psoriatic patient suffering from severe OSA is not different from that of a patient with severe OSA and is not associated with psoriasis severity indexes. OSA psoriatic patients were not compliant with CPAP treatment in comparison with OSA patients without psoriasis.

CONCLUSION

Psoriasis may represent an independent risk factor for OSA above and beyond significant comorbidities, anthropometric and metabolic parameters. Physicians should be aware of the bi-directional association of psoriasis and OSA. Managing psoriasis may be a potential target for preventing OSA as well as the potential cardiovascular mortality related to OSA and psoriasis.

The systemic nature of CKD

The accurate definition and staging of chronic kidney disease (CKD) is one of the major achievements of modern nephrology. Intensive research is now being undertaken to unravel the risk factors and pathophysiologic underpinnings of this disease. In particular, the relationships between the kidney and other organs have been comprehensively investigated in experimental and clinical studies in the last two decades. Owing to technological and analytical limitations, these links have been studied with a reductionist approach focusing on two organs at a time, such as the heart and the kidney or the bone and the kidney. Here, we discuss studies that highlight the complex and systemic nature of CKD. Energy balance, innate immunity and neuroendocrine signalling are highly integrated biological phenomena. The diseased kidney disrupts such integration and generates a high-risk phenotype with a clinical profile encompassing inflammation, protein-energy wasting, altered function of the autonomic and central nervous systems and cardiopulmonary, vascular and bone diseases. A systems biology approach to CKD using omics techniques will hopefully enable in-depth study of the pathophysiology of this systemic disease, and has the potential to unravel critical pathways that can be targeted for CKD prevention and therapy.

Prevalence of obstructive sleep apnea syndrome in a population of patients with transient global amnesia

OBJECTIVE

The etiology of transient global amnesia (TGA) is largely undetermined. The aim of this study was to investigate whether the prevalence of obstructive sleep apnea syndrome (OSAS), a condition associated with subtle changes in brain structures involved in memory processes, increases in subjects who have previously experienced a TGA episode.

METHODS

Twenty-nine patients who had had a TGA episode were included. A case-control model was used, matching cases with controls by sex, age, and body mass index category. Diagnosis of OSAS was based on the results of the Berlin Questionnaire, which was later confirmed by means of an all-night polysomnography recording.

RESULTS

The prevalence of OSAS among TGA patients was significantly higher with respect to that in controls (44.8% vs 13.8%, p = 0.020, χ² test). At logistic regression model, subjects with TGA had an odds ratio of 8.409 (95% confidence interval = 1.674-42.243; p = 0.010) of having OSAS when compared with controls.

CONCLUSIONS

According to our findings, an accurate investigation of sleep disturbances could be considered for a complete assessment of patients with TGA. The subtle cerebral anatomo-functional damage induced by the repeated nocturnal apneic episodes may be a pathophysiologic link between OSAS and TGA.

Effects of renal sympathetic denervation on blood pressure, sleep apnoea severity and metabolic indices: a prospective cohort study

BACKGROUND

Catheter-based renal sympathetic denervation (RSD) significantly reduces blood pressure in patients with resistant hypertension, who commonly have obstructive sleep apnoea (OSA). These patients are considered particularly responsive to the antihypertensive effects of RSD, but additional benefits of metabolic control on sleep apnoea severity have not been thoroughly investigated.

METHODS

The effect of RSD was evaluated prospectively in a cohort of patients with OSA (apnoea-hypopnea index (AHI) ≥15 events per hour and an Epworth Sleepiness Scale (ESS) score ≤9) and treatment resistant hypertension. Changes in blood pressure, polysomnographic parameters and metabolic indices were evaluated at baseline and six months post procedure.

RESULTS

At baseline, mean office blood pressure was 166.3/92.8 (14.5/11.7) mmHg and mean ambulatory blood pressure was 154.0/87.3 (11.9/8.5) mmHg. At six months post RSD, mean office blood pressure reduced by 6.6/6.5 (1.9/2.0) mmHg (p < 0.05) and mean ambulatory blood pressure reduced by 8.3/6.2 (2.3/2.0) (p < 0.05). The mean AHI at baseline was 21.3 events/h and 20.5 events/h at six months post RSD, with a mean reduction of 0.9 events/h (95% CI -0.7-1.6, p = 0.39). Glucose at two hours/2 h following tolerance testing reduced by 1.14 mmol/L (95% CI 0.22-2.06, p = 0.03) but changes in other metabolic indices were not statistically significant.

CONCLUSION

In patients with resistant hypertension and OSA, RSD resulted in modest improvements in blood pressure control, but no significant changes in sleep apnoea severity. Our study showed small increments in glucose tolerance but no significant changes in other markers of carbohydrate or lipid metabolism.

Serum from obstructive sleep apnea patients induces inflammatory responses in coronary artery endothelial cells

BACKGROUND AND AIMS

Obstructive sleep apnea (OSA) is characterized by intermittent airway obstruction and systemic hypoxia during sleep, which can contribute to an increase in reactive oxygen species, vascular remodeling, vasoconstriction and ultimately cardiovascular disease. Continuous positive airway pressure (CPAP) is a clinical therapy that maintains airway patency and mitigates several symptoms of OSA. However, it is currently unknown whether CPAP therapy also reduces the overall inflammatory potential in the circulation; to address this in an unbiased manner, we applied a novel endothelial biosensor approach, the serum cumulative inflammatory potential (SCIP) assay.

METHODS

We studied healthy controls (n = 7), OSA subjects receiving no treatment, (OSA controls) (n = 7) and OSA subjects receiving CPAP for 3 months (n = 8). Serum was obtained from OSA subjects before and after CPAP or no treatment. A battery of quantitative and functional assays was performed to assess the serum inflammatory potential, in terms of endothelial responses. For the SCIP assay, human coronary artery endothelial cells (hCAECs) were incubated with 5% serum in media from individual subjects for 4 h. qPCR was performed to assess endothelial inflammatory transcript (ICAM-1, VCAM-1, IL-8, P-selectin, CCL5, and CXCL12) responses to serum. Additionally, transendothelial resistance was measured in serum-incubated hCAECs following leukocyte challenge.

RESULTS

hCAECs exhibited significant increases in VCAM-1, ICAM-1, IL-8 and P-selectin mRNA when incubated with serum from OSA patients compared to serum from healthy control subjects. Furthermore, compared to no treatment, serum from CPAP-treated individuals was less potent at inducing inflammatory gene expression in the SCIP assay. Similarly, in a leukocyte adhesion assay, naïve cells treated with serum from patients who received CPAP exhibited improved endothelial barrier function than cells treated with OSA control serum.

CONCLUSIONS

OSA results in greater serum inflammatory potential, thereby driving endothelial activation and dysfunction.

Fractalkine in obstructive sleep apnea patients

BACKGROUND

Obstructive sleep apnea (OSA) is the most common sleep disorder affecting 2-4 % of the adult population. In addition to several potential mechanisms, inflammation is one of the suggested etiological factors in OSA. Fractalkine/CX3CL1 which is detected in activated or stressed endothelium, smooth muscle cells, skeletal muscle cells, macrophages, neurons, and hepatocytes is an inflammatory marker and attracts attention of sleep specialists in OSA pathogenesis. In this study, we had two goals. The first one was to investigate the role of fractalkine in OSA pathogenesis while the second one was to detect the impact of OSA treatment with positive airway pressure (PAP) on serum fractalkine levels.

METHOD

This study included 34 patients (6 females, 28 males) diagnosed as OSA and 20 healthy controls (4 females, 16 males). Initial serum fractalkine levels of both groups were first evaluated in order to demonstrate any potential relation of OSA with fractalkine. Subsequently, serum fractalkine levels of the OSA patients were evaluated following 1 week of PAP treatment to demonstrate the impact of PAP treatment on serum fractalkine levels.

RESULTS

Although there was no significant difference between OSA patients and healthy controls by means of plasma fractalkine levels (p, 0.67) statistically, plasma fractalkine levels significantly decreased in OSA patients after 1 week of PAP treatment (p, 0.001).

CONCLUSION

This study showed that fractalkine, a potential mediator of chronic inflammation, was not sensitive in diagnosing OSA but might be an indicator of the success of OSA treatment.

Interaction between Obstructive Sleep Apnea and Shortened Telomere Length on Brain White Matter Abnormality

STUDY OBJECTIVES

Age-related brain white matter changes (WMC) have been associated separately with obstructive sleep apnea (OSA) and short telomere length (TL). No studies have examined their interaction effect on WMC.

METHODS

This is a cross-sectional study with a community-based sample of 420 participants (mean age, 61.3 ± 7.2) from the Korean Genome and Epidemiology Study during 2011-2012. An overnight fasted blood sample was taken to determine glucose and blood lipid levels at the sleep laboratory of Korea University Ansan Hospital. The status of brain WMC was determined using structural magnetic resonance imaging at 1.5 Tesla. Overnight polysomnography was performed, and leukocyte TL was measured. OSA was determined based on apnea-hypopnea index, and short TL was defined as the lowest quartile of the study participants.

RESULTS

Adjusting for age, sex, BMI, smoking, drinking, snoring, and hypertension, odds ratio (OR) of brain WMC was estimated using multivariate logistic regression. The odds ratio was significant for cardiovascular disease (OR, 4.5; 95% CI, 1.2-16.3) and OSA (OR, 4.0; 95% CI, 1.0-15.2) among those with short TL; and for diabetes (OR, 3.0; 95% CI, 1.3-13.0) and age (OR, 1.1; 95% CI, 1.0-1.1) among those with longer TL. Interaction effect of OSA and short TL (OR, 4.3; 95% CI, 1.4-13.8) was significant, compared to those with neither OSA nor short TL.

CONCLUSIONS

This study provides a first evidence of mediated interaction of short TL with OSA on brain WMC in a community-based sample. The results generate new hypotheses regarding mechanisms of impaired brain health in sleep apnea.

Changes in four plasma adipokines before and after sleep in OSAS patients

OBJECTIVES

This study aimed to investigate whether plasma levels of four adipokines (chemerin, macrophage migratory inhibitory factor [MIF], visceral adipose tissue-derived serine protease inhibitor [vaspin] and chemokine CXCL5) are associated with the presence of obstructive sleep apnea syndrome (OSAS) in patients.

METHODS

A total of 58 male patients with OSAS and 16 healthy male subjects were enrolled in this study.

RESULTS

Four plasma adipokines (chemerin, MIF, vaspin and chemokine CXCL5) were significantly higher (P < 0.05) in severe OSAS patients than in the control group after polysomnography. Plasma levels of these four adipokines were higher (P < 0.05) after sleep than before sleep. These levels were also associated with anthropometric measurements for BMI, neck circumference, body fat percentage, sleep parameters including the apnea/hypopnea index (AHI) and minimum SaO₂ %. Multiple regression analyses showed that BMI, AHI and mean SaO₂ % were major factors affecting the four plasma adipokine levels in OSAS patients.

CONCLUSIONS

Plasma chemerin, MIF, vaspin and chemokine CXCL5 levels were severely elevated with OSAS, and were also connected with obesity.

Bariatric Surgery or Non-Surgical Weight Loss for Obstructive Sleep Apnoea? A Systematic Review and Comparison of Meta-analyses

BACKGROUND

Obstructive sleep apnoea (OSA) is a well-recognised complication of obesity. Non-surgical weight loss (medical, behavioural and lifestyle interventions) may improve OSA outcomes, although long-term weight control remains challenging. Bariatric surgery offers a successful strategy for long-term weight loss and symptom resolution.

OBJECTIVES

To comparatively appraise bariatric surgery vs. non-surgical weight loss interventions in OSA treatment utilising body mass index (BMI) and apnoea-hypopnoea index (AHI) as objective measures of weight loss and apnoea severity.

METHODS

A systematic literature review revealed 19 surgical (n = 525) and 20 non-surgical (n = 825) studies reporting the primary endpoints of BMI and AHI before and after intervention. Data were meta-analysed using random effects modelling. Subgroup analysis, quality scoring and risk of bias were assessed.

RESULTS

Surgical patients had a mean pre-intervention BMI of 51.3 and achieved a significant 14 kg/m(2) weighted decrease in BMI (95%CI [11.91, 16.44]), with a 29/h weighted decrease in AHI (95%CI [22.41, 36.74]). Non-surgical patients had a mean pre-intervention BMI of 38.3 and achieved a significant weighted decrease in BMI of 3.1 kg/m(2) (95%CI [2.42, 3.79]), with a weighted decrease in AHI of 11/h (95%CI [7.81, 14.98]). Heterogeneity was high across all outcomes.

CONCLUSIONS

Both bariatric surgery and non-surgical weight loss may have significant beneficial effects on OSA through BMI and AHI reduction. However, bariatric surgery may offer markedly greater improvement in BMI and AHI than non-surgical alternatives. Future studies must address the lack of randomised controlled and comparative trials in order to confirm the exact relationship between metabolic surgery and non-surgical weight loss interventions in OSA resolution.