Obstructive sleep apnea and type 2 diabetes: interacting epidemics

Cytosolic Escape of Mitochondrial DNA Triggers cGAS-STING Pathway-Dependent Neuronal PANoptosis in Response to Intermittent Hypoxia

Intermittent hypoxia (IH) is the predominant pathophysiological disturbance in obstructive sleep apnea (OSA), characterized by neuronal cell death and neurocognitive impairment. We focus on the accumulated mitochondrial DNA (mtDNA) in the cytosol, which acts as a damage-associated molecular pattern (DAMP) and activates the cyclic GMP-AMP synthase (cGAS)-stimulator of interferon genes (STING) pathway, a known trigger for immune responses and neuronal death in degenerative diseases. However, the specific role and mechanism of the mtDNA-cGAS-STING axis in IH-induced neural damage remain largely unexplored. Here, we investigated the involvement of PANoptosis, a novel type of programmed cell death linked to cytosolic mtDNA accumulation and the cGAS-STING pathway activation, in neuronal cell death induced by IH. Our study found that PANoptosis occurred in primary cultures of hippocampal neurons and HT22 cell lines exposed to IH. In addition, we discovered that during IH, mtDNA released into the cytoplasm via the mitochondrial permeability transition pore (mPTP) activates the cGAS-STING pathway, exacerbating PANoptosis-associated neuronal death. Pharmacologically inhibiting mPTP opening or depleting mtDNA significantly reduced cGAS-STING pathway activation and PANoptosis in HT22 cells under IH. Moreover, our findings indicated that the cGAS-STING pathway primarily promotes PANoptosis by modulating endoplasmic reticulum (ER) stress. Inhibiting or silencing the cGAS-STING pathway substantially reduced ER stress-mediated neuronal death and PANoptosis, while lentivirus-mediated STING overexpression exacerbated these effects. In summary, our study elucidates that cytosolic escape of mtDNA triggers cGAS-STING pathway-dependent neuronal PANoptosis in response to IH, mainly through regulating ER stress. The discovery of the novel mechanism provides theoretical support for the prevention and treatment of neuronal damage and cognitive impairment in patients with OSA.

Multimodal data integration for enhanced longitudinal prediction for cardiac and cerebrovascular events following initial diagnosis of obstructive sleep apnea syndrome

Background

Obstructive sleep apnea syndrome (OSAS), a prevalent condition, often coexists with intricate metabolic issues and is frequently associated with negative cardiovascular outcomes. We developed a longitudinal prediction model integrating multimodal data for cardiovascular risk stratification of patients with an initial diagnosis of OSAS.

Methods

We reviewed the data of patients with new-onset OSAS who underwent diagnostic polysomnography between 2018-19. Patients were treated using standard treatment regimens according to clinical practice guidelines.

Results

Over a median follow-up of 32 months, 98/729 participants (13.4%) experienced our composite outcome. At a ratio of 7:3, cases were randomly divided into development (n = 510) and validation (n = 219) cohorts. A prediction nomogram was created using six clinical factors - sex, age, diabetes mellitus, history of coronary artery disease, triglyceride-glucose index, and apnea-hypopnea index. The prediction nomogram showed excellent discriminatory power, based on Harrell's C-index values of 0.826 (95% confidence interval (CI) = 0.779-0.873) for the development cohort and 0.877 (95% CI = 0.824-0.93) for the validation cohort. Moreover, comparing the predicted and observed major adverse cardiac and cerebrovascular events in both development and validation cohorts indicated that the prediction nomogram was well-calibrated. Decision curve analysis demonstrated the good clinical applicability of the prediction nomogram.

Conclusions

Our findings demonstrated the construction of an innovative visualisation tool that utilises various types of data to predict poor outcomes in Chinese patients diagnosed with OSAS, providing accurate and personalised therapy.

Registration

Chinese Clinical Trial Registry ChiCTR2300075727.

Influence of Obstructive Sleep Apnea on the Risk of Dental Caries: Insights from a 13-Year Population-Based Retrospective Study

KNOWLEDGE TRANSFER STATEMENT

Obstructive sleep apnea has been proven to have a great negative impact on patients, and the relationship between sleep apnea and dental caries is still inconclusive. Our study shows that patients with sleep apnea and those older than 45 y have a significant risk of dental caries.

Association of obstructive sleep apnea symptoms with all-cause mortality and cause-specific mortality in adults with or without diabetes: A cohort study based on the NHANES

BACKGROUND

The association between obstructive sleep apnea syndrome (OSAS) and mortality has not been extensively researched among individuals with varying diabetic status. This study aimed to compare the relationship of OSAS with all-cause and cause-specific mortality in US individuals with or without diabetes based on data from the National Health and Nutrition Examination Survey (NHANES).

METHODS

The study included participants from the NHANES 2005-2008 and 2015-2018 cycles with follow-up information. OSAS data (OSAS.MAP10) was estimated from the questionnaire. Hazard ratios (HRs) and the 95% confidence interval (CI) of OSAS for mortality were calculated by Cox regression analysis in populations with different diabetes status. The relationships between OSAS and mortality risk were examined using survival curves and restricted cubic spline curves.

RESULTS

A total of 13 761 participants with 7.68 ± 0.042 follow-up years were included. In the nondiabetic group, OSAS.MAP10 was positively associated with all-cause, cardiovascular, and cancer mortality. In individuals with prediabetes, OSAS.MAP10 was positively related to all-cause mortality (HR 1.11 [95% CI: 1.03-1.20]) and cardiovascular mortality (HR 1.17 [95% CI: 1.03-1.33]). The relationship between OSAS.MAP10 and the risk of all-cause mortality and cancer mortality exhibited L-shaped curves in diabetes patients (both with nonlinear p values <.01). Further threshold effect analysis revealed that OSAS was positively related to death risk when OSAS.MAP10 exceeded the threshold scores.

CONCLUSION

The relationship between OSAS and mortality differed among participants with or without diabetes. Individualized clinical treatment plans should be developed in clinical practice to reduce the risk of death for patients with different metabolic conditions.

Habitual Short Sleep Duration, Diet, and Development of Type 2 Diabetes in Adults

Importance

Understanding the interplay between sleep duration, dietary habits, and the risk of developing type 2 diabetes (T2D) is crucial for public health and diabetes prevention strategies.

Objective

To investigate the associations of type of diet and duration of sleep with the development of T2D.

Design, Setting, and Participants

Data derived from the UK Biobank baseline investigation (2006-2010) were analyzed for this cohort study between May 1 and September 30, 2023. The association between sleep duration and healthy dietary patterns with the risk of T2D was investigated during a median (IQR) follow-up of 12.5 (11.8-13.2) years (end of follow-up, September 30, 2021).

Exposure

For the analysis, 247 867 participants were categorized into 4 sleep duration groups: normal (7-8 hours per day), mild short (6 hours per day), moderate short (5 hours per day), and extreme short (3-4 hours per day). Their dietary habits were evaluated based on population-specific consumption of red meat, processed meat, fruits, vegetables, and fish, resulting in a healthy diet score ranging from 0 (unhealthiest) to 5 (healthiest).

Main Outcomes and Measures

Cox proportional hazards regression analysis was used to calculate hazard ratios (HRs) and 95% CIs for the development of T2D across various sleep duration groups and healthy diet scores.

Results

The cohort comprised 247 867 participants with a mean [SD] age of 55.9 [8.1] years, of whom 52.3% were female. During the follow-up, 3.2% of participants were diagnosed with T2D based on hospital registry data. Cox regression analysis, adjusted for confounding variables, indicated a significant increase in the risk of T2D among participants with 5 hours or less of daily sleep. Individuals sleeping 5 hours per day exhibited a 1.16 adjusted HR (95% CI, 1.05-1.28), and individuals sleeping 3 to 4 hours per day exhibited a 1.41 adjusted HR (95% CI, 1.19-1.68) compared with individuals with normal sleep duration. Furthermore, individuals with the healthiest dietary patterns had a reduced risk of T2D (HR, 0.75 [95% CI, 0.63-0.88]). The association between short sleep duration and increased risk of T2D persisted even for individuals following a healthy diet, but there was no multiplicative interaction between sleep duration and healthy diet score.

Conclusions and Relevance

In this cohort study involving UK residents, habitual short sleep duration was associated with increased risk of developing T2D. This association persisted even among participants who maintained a healthy diet. To validate these findings, further longitudinal studies are needed, incorporating repeated measures of sleep (including objective assessments) and dietary habits.

Preoperative risk evaluation and perioperative management of patients with obstructive sleep apnea: a narrative review

Obstructive sleep apnea (OSA) is a common sleep-breathing disorder associated with significant comorbidities and perioperative complications. This narrative review is aimed at comprehensively overviewing preoperative risk evaluation and perioperative management strategies for patients with OSA. OSA is characterized by recurrent episodes of upper airway obstruction during sleep leading to hypoxemia and arousal. Anatomical features, such as upper airway narrowing and obesity, contribute to the development of OSA. OSA can be diagnosed based on polysomnography findings, and positive airway pressure therapy is the mainstay of treatment. However, alternative therapies, such as oral appliances or upper airway surgery, can be considered for patients with intolerance. Patients with OSA face perioperative challenges due to difficult airway management, comorbidities, and effects of sedatives and analgesics. Anatomical changes, reduced upper airway muscle tone, and obesity increase the risks of airway obstruction, and difficulties in intubation and mask ventilation. OSA-related comorbidities, such as cardiovascular and respiratory disorders, further increase perioperative risks. Sedatives and opioids can exacerbate respiratory depression and compromise airway patency. Therefore, careful consideration of alternative pain management options is necessary. Although the association between OSA and postoperative mortality remains controversial, concerns exist regarding adverse outcomes in patients with OSA. Understanding the pathophysiology of OSA, implementing appropriate preoperative evaluations, and tailoring perioperative management strategies are vital to ensure patient safety and optimize surgical outcomes.

International Consensus Statement on Obstructive Sleep Apnea

BACKGROUND

Evaluation and interpretation of the literature on obstructive sleep apnea (OSA) allows for consolidation and determination of the key factors important for clinical management of the adult OSA patient. Toward this goal, an international collaborative of multidisciplinary experts in sleep apnea evaluation and treatment have produced the International Consensus statement on Obstructive Sleep Apnea (ICS:OSA).

METHODS

Using previously defined methodology, focal topics in OSA were assigned as literature review (LR), evidence-based review (EBR), or evidence-based review with recommendations (EBR-R) formats. Each topic incorporated the available and relevant evidence which was summarized and graded on study quality. Each topic and section underwent iterative review and the ICS:OSA was created and reviewed by all authors for consensus.

RESULTS

The ICS:OSA addresses OSA syndrome definitions, pathophysiology, epidemiology, risk factors for disease, screening methods, diagnostic testing types, multiple treatment modalities, and effects of OSA treatment on multiple OSA-associated comorbidities. Specific focus on outcomes with positive airway pressure (PAP) and surgical treatments were evaluated.

CONCLUSION

This review of the literature consolidates the available knowledge and identifies the limitations of the current evidence on OSA. This effort aims to create a resource for OSA evidence-based practice and identify future research needs. Knowledge gaps and research opportunities include improving the metrics of OSA disease, determining the optimal OSA screening paradigms, developing strategies for PAP adherence and longitudinal care, enhancing selection of PAP alternatives and surgery, understanding health risk outcomes, and translating evidence into individualized approaches to therapy.

Carotid body: an emerging target for cardiometabolic co-morbidities

NEW FINDINGS

What is the topic of this review? Regarding the global metabolic syndrome crisis, this review focuses on common mechanisms for high blood sugar and high blood pressure. Connections are made between the homeostatic regulation of blood pressure and blood sugar and their dysregulation to reveal signalling mechanisms converging on the carotid body. What advances does it highlight? The carotid body plays a major part in the generation of excessive sympathetic activity in diabetes and also underpins diabetic hypertension. As treatment of diabetic hypertension is notoriously difficult, we propose that novel receptors within the carotid body may provide a novel treatment strategy.

ABSTRACT

The maintenance of glucose homeostasis is obligatory for health and survival. It relies on peripheral glucose sensing and signalling between the brain and peripheral organs via hormonal and neural responses that restore euglycaemia. Failure of these mechanisms causes hyperglycaemia or diabetes. Current anti-diabetic medications control blood glucose but many patients remain with hyperglycemic condition. Diabetes is often associated with hypertension; the latter is more difficult to control in hyperglycaemic conditions. We ask whether a better understanding of the regulatory mechanisms of glucose control could improve treatment of both diabetes and hypertension when they co-exist. With the involvement of the carotid body (CB) in glucose sensing, metabolic regulation and control of sympathetic nerve activity, we consider the CB as a potential treatment target for both diabetes and hypertension. We provide an update on the role of the CB in glucose sensing and glucose homeostasis. Physiologically, hypoglycaemia stimulates the release of hormones such as glucagon and adrenaline, which mobilize or synthesize glucose; however, these counter-regulatory responses were markedly attenuated after denervation of the CBs in animals. Also, CB denervation prevents and reverses insulin resistance and glucose intolerance. We discuss the CB as a metabolic regulator (not just a sensor of blood gases) and consider recent evidence of novel 'metabolic' receptors within the CB and putative signalling peptides that may control glucose homeostasis via modulation of the sympathetic nervous system. The evidence presented may inform future clinical strategies in the treatment of patients with both diabetes and hypertension, which may include the CB.

Muscle Lipid Oxidation Is Not Affected by Obstructive Sleep Apnea in Diabetes and Healthy Subjects

The molecular mechanisms linking obstructive sleep apnea (OSA) with type 2 diabetes mellitus (T2DM) remain unclear. This study investigated the effect of OSA on skeletal muscle lipid oxidation in nondiabetic controls and in type 2 diabetes (T2DM) patients. Forty-four participants matched for age and adiposity were enrolled: nondiabetic controls (control, n = 14), nondiabetic patients with severe OSA (OSA, n = 9), T2DM patients with no OSA (T2DM, n = 10), and T2DM patients with severe OSA (T2DM + OSA, n = 11). A skeletal muscle biopsy was performed; gene and protein expressions were determined and lipid oxidation was analyzed. An intravenous glucose tolerance test was performed to investigate glucose homeostasis. No differences in lipid oxidation (178.2 ± 57.1, 161.7 ± 22.4, 169.3 ± 50.9, and 140.0 ± 24.1 pmol/min/mg for control, OSA, T2DM, and T2DM+OSA, respectively; p > 0.05) or gene and protein expressions were observed between the groups. The disposition index, acute insulin response to glucose, insulin resistance, plasma insulin, glucose, and HBA1C progressively worsened in the following order: control, OSA, T2DM, and T2DM + OSA (p for trend <0.05). No association was observed between the muscle lipid oxidation and the glucose metabolism variables. We conclude that severe OSA is not associated with reduced muscle lipid oxidation and that metabolic derangements in OSA are not mediated through impaired muscle lipid oxidation.

Elevated fasting insulin results in snoring: A view emerged from causal evaluation of glycemic traits and snoring

BACKGROUND

Snoring and impaired glucose metabolism are common clinical manifestations and associated. The purpose of our study is to estimate the causal associations between snoring and glycemic traits.

METHODS

We compared the weighted mean differences (WMD) for fasting insulin (FINS), glycosylated haemoglobin (HbA1c), fasting blood glucose (FBG) and 2 h-glucose post-challenge (2hGlu) levels between snorers and non-snorers by meta-analysis. Then, we obtained summary statistics from published GWAS of snoring and glycemic traits to perform bidirectional two-sample MR. Inverse variance weighting (IVW) method was applied as major estimate while MR Egger, Weighted median and MR-Robust Adjusted Profile Score (RAPS) played a subsidiary role.

RESULTS

Snoring participants had higher FBG (WMD = 0.14 mmol/L, 95%CI = [0.10,0.19]), HbA1c (WMD = 0.10%, 95%CI = [0.07,0.13]), FINS (WMD = 0.92μIU/mL, 95%CI = [0.59,1.26]) and 2hGlu (WMD = 0.30 mmol/L, 95%CI = [0.06,0.55]) levels than non-snorers. Further, elevated FINS levels shown robust causal effect on snoring (IVW: OR = 1.07, 95%CI = [1.02,1.12], p = 2.2 × 10^-3 ), which was consistent by complementary methods of MR Egger (OR = 1.14, 95%CI = [1.01-1.30], p = 4.72 × 10^-2 ), Weighted median (OR = 1.11, 95%CI = [1.07,1.15], p = 1.53 × 10^-7 ) and MR RAPS (OR = 1.07, 95% CI = [1.05,1.10], p = 2.81 × 10^-9 ). Such causal situation was stable after identifying and removing the outliers in sensitivity analysis. However, there was no causality of snoring on increasing FINS levels. Additionally, there were no causal associations between snoring and other three traits of FBG, HbA1c and 2hGlu levels from either direction.

CONCLUSIONS

Snorers are subjected to higher FBG, HbA1c, FINS and 2hGlu levels, and elevated FINS levels further provides robust causality on snoring, suggesting that behind common snoring may lie hyperinsulinemia or insulin resistance.

The Impact of Intermittent Hypoxia on Metabolism and Cognition

Intermittent hypoxia (IH), one of the primary pathologies of sleep apnea syndrome (SAS), exposes cells throughout the body to repeated cycles of hypoxia/normoxia that result in oxidative stress and systemic inflammation. Since SAS is epidemiologically strongly correlated with type 2 diabetes/insulin resistance, obesity, hypertension, and dyslipidemia included in metabolic syndrome, the effects of IH on gene expression in the corresponding cells of each organ have been studied intensively to clarify the molecular mechanism of the association between SAS and metabolic syndrome. Dementia has recently been recognized as a serious health problem due to its increasing incidence, and a large body of evidence has shown its strong correlation with SAS and metabolic disorders. In this narrative review, we first outline the effects of IH on the expression of genes related to metabolism in neuronal cells, pancreatic β cells, hepatocytes, adipocytes, myocytes, and renal cells (mainly based on the results of our experiments). Next, we discuss the literature regarding the mechanisms by which metabolic disorders and IH develop dementia to understand how IH directly and indirectly leads to the development of dementia.

The prevalence of obstructive sleep apnoea risk factors in individuals with cognitive impairment: south London cross-sectional study

AIMS AND METHOD

We aimed to determine the prevalence of risk factors for obstructive sleep apnoea (OSA) in patients with mild cognitive impairment (MCI) or dementia. Using patient records across a 5 year period, we identified 16 855 patients with dementia or MCI. We gave scores for keywords relating to each modified STOP BANG parameter in patient progress notes. Based on individual scores, we stratified the population into groups with low, intermediate and high risk of OSA.

RESULTS

Our population had a high prevalence of risk factors and consequently high risk scores for OSA (18.21% high risk). Parameters directly related to sleep had a low prevalence.

CLINICAL IMPLICATIONS

The risk of developing or having OSA is high among patients with MCI and dementia. Low sleep parameter frequency probably suggests poor documentation of sleep rather than true prevalence. Our findings support the implementation of the STOP BANG or a similar screening tool as a standardised method to identify OSA risk in memory clinics.

Association of the Coexistence of Somnipathy and Diabetes With the Risks of Cardiovascular Disease Events, Stroke, and All‐Cause Mortality: A Systematic Review and Meta‐analysis

Background

Somnipathy and diabetes are independently associated with an increased risk of cardiovascular disease (CVD). However, whether a combination of both conditions is associated with a higher risk of CVD events remains uncertain. Therefore, the aim of this meta‐analysis was to clarify this association.

Methods and Results

We searched MEDLINE, Web of Science, EMBASE, ClinicalTrials.gov , and the Cochrane Central Register for Controlled Trials. We included randomized controlled trials, nonrandomized trials, and prospective observational cohort studies that assessed the combined effect of diabetes and comorbid somnipathy on CVD risk and mortality for at least 1 year. Outcomes included CVD, coronary heart disease, stroke, and all‐cause mortality. Twelve studies involving 582 267 participants were included in the meta‐analysis. Patients with somnipathy and comorbid diabetes exhibited increased risks of CVD, coronary heart disease, stroke, and all‐cause mortality (risk ratio [RR], 1.27 [95% CI, 1.12–1.45], P <0.0001; RR, 1.40 [95% CI, 1.21–1.62], P <0.0001; RR, 1.28 [95% CI, 1.08–1.52], P =0.004, and RR, 1.56 [95% CI, 1.26–1.94], P <0.0001, respectively).

Conclusions

The coexistence of somnipathy and diabetes is associated with higher risks of CVD, coronary heart disease, stroke, and mortality than somnipathy or diabetes alone. Resolving sleep problems in patients with diabetes may reduce the risks of CVD, stroke, and mortality.

Registration Information

https://www.crd.york.ac.uk/prospero/ . Identifier: PROSPERO CRD42021274566.

Markers of ventricular repolarization and overall mortality in sleep disordered breathing

INTRODUCTION

Variability and prolongation of ventricular repolarization - measured by changes in QT interval and QT variability are independently associated with ventricular arrhythmias, sudden death, and mortality but such studies did not examine the role of sleep-disordered breathing. We aimed to determine whether sleep-disordered breathing moderated the association between measures of ventricular repolarization and overall mortality.

METHODS

Eight hundred participants were randomly selected from each of the following four groups in the Sleep Heart Health Study: mild, moderate, severe or no sleep disordered breathing (n = 200 each). Overnight electrocardiograms were analyzed for QTc duration and QT variability (standard deviation of QT intervals, normalized QT interval variance and the short-term interval beat-to-beat QT variability). Cox proportional hazards penalized regression modeling was used to identify predictors of mortality.

RESULTS

Eight hundred of 5600 participants were randomly selected. The participants (68 ± 10 years; 56.8% male) were followed for an average of 8.2 years during which time 222 (28.4%) died. QTc, SDQT, and QTVN were associated with the presence of SDB (p = 0.002, p = 0.014, and p = 0.024, respectively). After adjusting for covariates, the presence of sleep-disordered breathing did not moderate the association between QTc length, QT variability and mortality (p > 0.05).

CONCLUSION

Sleep-disordered breathing was associated with some measures of ventricular repolarization. However, sleep-disordered breathing was not an effect modifier for the relationship between QTc and QT variability and mortality.

Results of a 1-Year Follow-Up Sleep Apnea Screening and Referral Initiative During Routine Yearly Examination of Environmental Inspection Workers

BACKGROUND

There are strong links between obstructive sleep apnea (OSA), chronic disease, mental health, job performance, and motor vehicle accidents. Corporate wellness clinics and health monitoring programs present ideal settings to educate and screen employees for OSA.

METHODS

In January 2020, the Stop-Bang Sleep Apnea Questionnaire was added to the yearly health monitoring program of 571 State of Texas air, water, and hazardous waste workers as part of routine care. Medium- and high-risk (HR) scoring employees were counseled to seek follow-up care from a primary-care provider (PCP). The January 2021 exams provided an opportunity to determine the success of counseling efforts.

FINDINGS

Of the 479 returning employees in 2021, 24 (49%) of HR and 17 (21.8%) of intermediate risk (IR) had discussed OSA with a PCP. Seven (14.3%) HR and 1 (<1%) IR employee underwent a sleep study and 4 (8.2%) were prescribed continuous positive airway pressure (CPAP).

CONCLUSIONS/APPLICATION TO PRACTICE

Screening for OSA at the workplace was inexpensive and, when diagnosed and treated, can mitigate associated chronic disease, improve worker productivity, and reduce associated accidents and injuries. The described OSA screening delivered value to the employer and employees. The screening was performed at a very low cost, involved little time on the part of the nurse practitioner and employees, brought signs and symptoms of OSA to the consciousness level of 571 employees, encouraged at-risk participants to discuss OSA with a PCP and led to 4 (8.2%) being prescribed CPAP.

Anorexigenic Effects of Intermittent Hypoxia on the Gut-Brain Axis in Sleep Apnea Syndrome

Sleep apnea syndrome (SAS) is a breathing disorder characterized by recurrent episodes of upper-airway collapse, resulting in intermittent hypoxia (IH) during sleep. Experimental studies with animals and cellular models have indicated that IH leads to attenuation of glucose-induced insulin secretion from pancreatic β cells and to enhancement of insulin resistance in peripheral tissues and cells, such as the liver (hepatocytes), adipose tissue (adipocytes), and skeletal muscles (myocytes), both of which could lead to obesity. Although obesity is widely recognized as a major factor in SAS, it is controversial whether the development of SAS could contribute directly to obesity, and the effect of IH on the expression of appetite regulatory genes remains elusive. Appetite is regulated appropriately by both the hypothalamus and the gut as a gut-brain axis driven by differential neural and hormonal signals. In this review, we summarized the recent epidemiological findings on the relationship between SAS and feeding behavior and focused on the anorexigenic effects of IH on the gut-brain axis by the IH-induced up-regulation of proopiomelanocortin and cocaine- and amphetamine-regulated transcript in neuronal cells and the IH-induced up-regulation of peptide YY, glucagon-like peptide-1 and neurotensin in enteroendocrine cells and their molecular mechanisms.

Postprandial glucose and HbA1c are associated with severity of obstructive sleep apnoea in non-diabetic obese subjects

INTRODUCTION

Obstructive sleep apnoea (OSA) is an underdiagnosed condition frequently associated with glycaemic control impairment in patients with type 2 diabetes.

AIM

To assess the relationship between glycometabolic parameters and OSA in obese non-diabetic subjects.

METHODS

Ninety consecutive subjects (mean age 44.9 ± 12 years, mean BMI 42.1 ± 9 kg/m²) underwent polysomnography and a 2-h oral glucose tolerance test (OGTT).

RESULTS

OSA was identified in 75% of subjects, with a higher prevalence of males compared to the group of subjects without OSA (62% vs 32%, p = 0.02). Patients with OSA had comparable BMI (42.8 kg/m² vs 39.4 kg/m²), a higher average HbA1c (5.8% vs 5.4%, p < 0.001), plasma glucose at 120 min during OGTT (2 h-PG; 123 mg/dl vs 97 mg/dl, p = 0.009) and diastolic blood pressure (81.1 mmHg vs 76.2 mmHg, p = 0.046) than obese subjects without OSA. HbA1c and 2 h-PG were found to be correlated with the apnoea-hypopnoea index (AHI; r = 0.35 and r = 0.42, respectively) and with percent of sleep time with oxyhaemoglobin saturation < 90% (ST90; r = 0.44 and r = 0.39, respectively). Further, in a linear regression model, ST90 and AHI were found to be the main determinants of 2 h-PG (β = 0.81, p < 0.01 and β = 0.75, p = 0.02, respectively) after controlling for age, sex, waist circumference, physical activity, and C-reactive protein. Similarly, ST90 and AHI persisted as independent determinants of HbA1c (β = 0.01, p = 0.01 and β = 0.01, p = 0.01, respectively).

CONCLUSION

Beyond the traditional clinical parameters, the presence of a normal-high value of 2 h-PG and HbA1c should raise suspicion of the presence of OSA in obese subjects.

Polysomnographic Phenotypes of Obstructive Sleep Apnea and Incident Type 2 Diabetes: Results from the DREAM Study

Rationale: Obstructive sleep apnea (OSA) is associated with cardiovascular disease and incident type 2 diabetes (T2DM). Seven OSA phenotypes, labeled on the basis of their most distinguishing polysomnographic features, have been shown to be differentially associated with incident cardiovascular disease. However, little is known about the relevance of polysomnographic phenotypes for the risk of T2DM. Objectives: To assess whether polysomnographic phenotypes are associated with incident T2DM and to compare the predictive value of baseline polysomnographic phenotypes with the Apnea-Hypopnea Index (AHI) for T2DM. Methods: The study included 840 individuals without baseline diabetes from a multisite observational U.S. veteran cohort who underwent OSA evaluation between 2000 and 2004, with follow-up through 2012. The primary outcome was incident T2DM, defined as no diagnosis at baseline and a new physician diagnosis confirmed by fasting blood glucose >126 mg/dL during follow-up. Relationships between the seven polysomnographic phenotypes (1. mild, 2. periodic limb movements of sleep [PLMS], 3. non-rapid eye movement and poor sleep, 4. rapid eye movement and hypoxia, 5. hypopnea and hypoxia, 6. arousal and poor sleep, and 7. combined severe) and incident T2DM were investigated using Cox proportional hazards regression and competing risk regression models with and without adjustment for baseline covariates. Likelihood ratio tests were conducted to compare the predictive value of the phenotypes with the AHI. Results: During a median follow-up period of 61 months, 122 (14.5%) patients developed incident T2DM. After adjustment for baseline sociodemographics, fasting blood glucose, body mass index, comorbidities, and behavioral risk factors, hazard ratios among persons with "hypopnea and hypoxia" and "PLMS" phenotypes as compared with persons with "mild" phenotype were 3.18 (95% confidence interval [CI], 1.53-6.61] and 2.26 (95% CI, 1.06-4.83) for incident T2DM, respectively. Mild OSA (5 ⩽ AHI < 15) (vs. no OSA) was directly associated with incident T2DM in both unadjusted and multivariable-adjusted regression models. The addition of polysomnographic phenotypes, but not AHI, to known T2DM risk factors greatly improved the predictive value of the computed prediction model. Conclusions: Polysomnographic phenotypes "hypopnea and hypoxia" and "PLMS" independently predict risk of T2DM among a predominantly male veteran population. Polysomnographic phenotypes improved T2DM risk prediction comared with the use of AHI.

Effects of Intermittent Hypoxia on Cytokine Expression Involved in Insulin Resistance

Sleep apnea syndrome (SAS) is a prevalent disorder characterized by recurrent apnea or hypoxia episodes leading to intermittent hypoxia (IH) and arousals during sleep. Currently, the relationship between SAS and metabolic diseases is being actively analyzed, and SAS is considered to be an independent risk factor for the development and progression of insulin resistance/type 2 diabetes (T2DM). Accumulating evidence suggests that the short cycles of decreased oxygen saturation and rapid reoxygenation, a typical feature of SAS, contribute to the development of glucose intolerance and insulin resistance. In addition to IH, several pathological conditions may also contribute to insulin resistance, including sympathetic nervous system hyperactivity, oxidative stress, vascular endothelial dysfunction, and the activation of inflammatory cytokines. However, the detailed mechanism by which IH induces insulin resistance in SAS patients has not been fully revealed. We have previously reported that IH stress may exacerbate insulin resistance/T2DM, especially in hepatocytes, adipocytes, and skeletal muscle cells, by causing abnormal cytokine expression/secretion from each cell. Adipose tissues, skeletal muscle, and the liver are the main endocrine organs producing hepatokines, adipokines, and myokines, respectively. In this review, we focus on the effect of IH on hepatokine, adipokine, and myokine expression.

Gender Differences in the Association Between Obstructive Sleep Apnea and Diabetes

OBJECTIVE

This study aimed to explore the association between obstructive sleep apnea (OSA) and diabetes in a Chinese population based on a cross-sectional analysis of patient data from a large tertiary care hospital in China and analyses whether there are any gender differences in this association.

METHODS

A total of 794 (615 men and 179 women) inpatients were involved in this study. Polysomnography (PSG) was used to diagnose OSA, and overnight PSG testing was performed on each subject included in this study. All study subjects were also diagnosed with whether they had diabetes by an endocrinologist in the hospital.

RESULTS

After adjusting for sex, age, smoking status, alcohol consumption and body mass index (BMI) groups, the results showed that the number of apnea-hypopnea index (AHI) events was a risk factor for diabetes, with a 9% (95% CI: 1-17%) increase in the risk of diabetes per unit increase, while subjects with higher (per unit increase) lowest oxygen saturation value monitored during the subject's sleep (LSaO2) with a 13% (95% CI: 4-22%) decrease in the risk of diabetes. Stratified analyses by gender, after adjustment, in men, OSA and its associated monitoring indicators were statistically significantly associated with diabetes [OR for severe OSA was 2.269 (95% CI: 1.164, 4.425), P=0.016, and OR for severe hypoxemia was 2.228 (95% CI: 1.145, 4.334), P=0.018], while not in women.

CONCLUSION

Our study found a significant association between OSA and diabetes in a Chinese clinical-based population as well as a dose-response relationship between the severity of AHI and severe hypoxemia (LSaO2 < 80%) and blood glucose, the association has gender difference and was only present significant association in men, which demonstrated that diabetes prevention and blood glucose screening and management should be enhanced for Chinese men with OSA.

Relationship between allergic rhinitis and nasal surgery success in patients with obstructive sleep apnea

OBJECTIVES

Nasal obstruction is common in patients with obstructive sleep apnea (OSA). Nonetheless, the effectiveness of isolated nasal surgery in treatment of OSA remains controversial. This study is to evaluate the subjective and objective outcome after isolated nasal surgery in patients with OSA and to determine the associated factors related to the success rate of isolated nasal surgery.

METHODS

The study population consisted of 35 patients with nasal obstruction who had been diagnosed with OSA and were undergoing septoplasty and inferior turbinate reduction to correct nasal pathologies. Preoperative drug-induced sleep endoscopy was performed to evaluate the obstruction site. Patients were assessed before and after nasal surgery using subjective outcomes measures, including the Visual Analog Scale and Epworth Sleepiness Scale, as well as by overnight polysomnography.

RESULTS

All patients experienced improved nasal breathing postoperatively. At 6 months postoperatively, patients exhibited significant symptomatic improvement in snoring, sleep apnea, morning headache, tiredness, and daytime sleepiness. Postoperative polysomnography revealed significant improvement in the apnea-hypopnea index, respiratory disturbance index, and percentage of time with oxygen saturation < 90%. Although the overall success rate of nasal surgery alone was 14.3%, the criteria for success were met in 50% of patients with allergic rhinitis. Furthermore, the success rate was significantly higher in patients with moderate to severe nasal obstruction than in patients with mild nasal obstruction.

CONCLUSION

Among patients with OSA, those with allergic rhinitis and severe nasal obstruction are likely to have a better surgical outcome following isolated nasal surgery.

Admission of Patients With Obstructive Sleep Apnea Undergoing Ambulatory Surgery in Otolaryngology-Head and Neck Surgery

Objectives:

Within Otolaryngology—Head and Neck Surgery (OHNS), obstructive sleep apnea (OSA) patients are frequently encountered. To implement policies and screening measures for admission of OSA patients undergoing ambulatory surgery, actual rates of admission must first be determined. We aimed to evaluate rates and reasons for admission of OSA patients after ambulatory OHNS surgery.

Methods:

Retrospective chart review was undertaken of all OSA patients undergoing elective day-surgery OHNS procedures at a tertiary center from January 1, 2018 to December 31, 2019. The primary outcome measure was percentage of OSA patients admitted to hospital after ambulatory OHNS surgery. Secondary outcome measures included reasons for admission. American Society of Anesthesiologists (ASA) score, perioperative complications, and patient demographics were captured.

Results:

There were 118 OSA patients, out of 1942 cases performed during the review period. Thirty-eight were excluded as the procedures were not considered ambulatory. The remaining 80 OSA patients were included for analysis, with an average age of 51.7, SD 13.8, and 30 (38%) females. The admission rate was 47.5% (38/80 patients). Admitted patients were older (P = .0061), and had higher ASA (P = .039). Indication for surgery or type of surgery did not differ among admitted and non-admitted patients. The majority of patients, 97% (37/38 patients), were admitted for post-operative monitoring.

Conclusion:

More than half of OSA patients did not require admission to hospital after ambulatory OHNS surgery, unaffected by indications for surgery or type of surgery. Higher ASA score and older age were found in admitted as compared to non-admitted patients.

Lysine demethylase KDM6B regulates HIF-1α-mediated systemic and cellular responses to intermittent hypoxia

Intermittent hypoxia (IH) is a hallmark manifestation of obstructive sleep apnea (OSA). Rodents treated with IH exhibit hypertension. Hypoxia-inducible factor (HIF)-1-dependent transcriptional activation of NADPH oxidases (Nox) and the resulting increase in reactive oxygen species (ROS) levels is a major molecular mechanism underlying IH/OSA-induced hypertension. Jumanji C (JmjC)-containing histone lysine demethylases (JmjC-KDMs) are coactivators of HIF-1-dependent transcriptional activation. In the present study, we tested the hypothesis that JmjC-KDMs are required for IH-evoked HIF-1 transcriptional activation of Nox4 and the ensuing hypertension. Studies were performed on pheochromocytoma (PC)12 cells and rats. IH increased KDM6B protein and enzyme activity in PC12 cells in an HIF-1-independent manner as evidenced by unaltered KDM6B activation by IH in HIF-1α shRNA-treated cells. Cells treated with IH showed increased HIF-1-dependent Nox4 transcription as indicated by increased HIF-1α binding to hypoxia-responsive element (HRE) sequence of the Nox4 gene promoter demonstrated by chromatin immunoprecipitation (ChiP) assay. Pharmacological blockade of KDM6B with GSKJ4, a specific KDM6 inhibitor, or genetic silencing of KDM6B with shRNA abolished IH-induced Nox4 transcriptional activation by blocking HIF-1α binding to the promoter of the Nox4 gene. Treating IH-exposed rats with GSKJ4 showed: 1) absence of KDM6B activation and HIF-1-dependent Nox4 transcription in the adrenal medullae, and 2) absence of elevated plasma catecholamines and hypertension. Collectively, these findings indicate that KDM6B functions as a coactivator of HIF-1-mediated Nox4 transactivation and demonstrates a hitherto uncharacterized role for KDMs in IH-induced hypertension by HIF-1.

Chronic Intermittent Hypoxia Induces Early-Stage Metabolic Dysfunction Independently of Adipose Tissue Deregulation

Several studies demonstrated a link between obstructive sleep apnea (OSA) and the development of insulin resistance. However, the main event triggering insulin resistance in OSA remains to be clarified. Herein, we investigated the effect of mild and severe chronic intermittent hypoxia (CIH) on whole-body metabolic deregulation and visceral adipose tissue dysfunction. Moreover, we studied the contribution of obesity to CIH-induced dysmetabolic states. Experiments were performed in male Wistar rats submitted to a control and high-fat (HF) diet. Two CIH protocols were tested: A mild CIH paradigm (5/6 hypoxic (5% O₂) cycles/h, 10.5 h/day) during 35 days and a severe CIH paradigm (30 hypoxic (5% O₂) cycles, 8 h/day) during 15 days. Fasting glycemia, insulinemia, insulin sensitivity, weight, and fat mass were assessed. Adipose tissue hypoxia, inflammation, angiogenesis, oxidative stress, and metabolism were investigated. Mild and severe CIH increased insulin levels and induced whole-body insulin resistance in control animals, effects not associated with weight gain. In control animals, CIH did not modify adipocytes perimeter as well as adipose tissue hypoxia, angiogenesis, inflammation or oxidative stress. In HF animals, severe CIH attenuated the increase in adipocytes perimeter, adipose tissue hypoxia, angiogenesis, and dysmetabolism. In conclusion, adipose tissue dysfunction is not the main trigger for initial dysmetabolism in CIH. CIH in an early stage might have a protective role against the deleterious effects of HF diet on adipose tissue metabolism.

Epidemiology of diabetes among South Asians in the United States: lessons from the MASALA study

South Asian individuals in the United States are at an increased risk of type 2 diabetes (T2DM); however, the mechanisms behind this are not well understood. The Mediators of Atherosclerosis in South Asians Living in America (MASALA) study is the only longitudinal cohort of South Asians in the United States and provides key insights as to the epidemiology of T2DM in South Asians. Evidence from the MASALA study suggests that South Asians experience a disproportionately high burden of prevalent and incident T2DM compared with members of other race/ethnic groups. Higher insulin resistance in South Asians, even with low body mass index (BMI), more impairment in insulin secretion, and greater deposition of ectopic fat likely play a role in T2DM etiology. Furthermore, South Asian migrants to the United States experience a range of factors related to acculturation, social networks, and religious beliefs, which may impact physical activity and dietary practices. Interventions to prevent T2DM in South Asians should include a focus on cultural factors related to health and should consider the complete mechanistic pathway and the relative contributions of insulin resistance, β cell dysfunction, and ectopic fat deposition on T2DM development in South Asians, particularly in those with lower BMI.

Metabolic dysfunction in OSA: Is there something new under the sun?

The growing number of patients with obstructive sleep apnea is challenging healthcare systems worldwide. Obstructive sleep apnea is characterized by chronic intermittent hypoxaemia, episodes of apnea and hypopnea, and fragmented sleep. Cardiovascular and metabolic diseases are common in obstructive sleep apnea, also in lean patients. Further, comorbidity burden is not unambiguously linked to the severity of obstructive sleep apnea. There is a growing body of evidence revealing diverse functions beyond the conventional tasks of different organs such as carotid body and gut microbiota. Chronic intermittent hypoxia and sleep loss due to sleep fragmentation are associated with insulin resistance. Indeed, carotid body is a multi-sensor organ not sensoring only hypoxia and hypercapnia but also acting as a metabolic sensor. The emerging evidence shows that obstructive sleep apnea and particularly chronic intermittent hypoxia is associated with non-alcoholic fatty liver disease. Gut dysbiosis seems to be an important factor in the pathophysiology of obstructive sleep apnea and its consequences. The impact of sleep fragmentation and intermittent hypoxia on the development of metabolic syndrome may be mediated via altered gut microbiota. Circadian misalignment seems to have an impact on the cardiometabolic risk in obstructive sleep apnea. Dysfunction of cerebral metabolism is also related to hypoxia and sleep fragmentation. Therefore, obstructive sleep apnea may alter cerebral metabolism and predispose to neurocognitive impairment. Moreover, recent data show that obstructive sleep apnea independently predicts impaired lipid levels. This mini-review will provide novel insights into the mechanisms of metabolic dysfunction in obstructive sleep apnea combining recent evidence from basic, translational and clinical research, and discuss the impact of positive airway pressure treatment on metabolic disorders.

Association between sleep quality and type 2 diabetes at 20-year follow-up in the Southall and Brent REvisited (SABRE) cohort: a triethnic analysis

Background

The risk of developing type 2 diabetes associated with poor sleep quality is comparable to other lifestyle factors (eg, overweight, physical inactivity). In the UK, these risk factors could not explain the two to three-fold excess risks in South-Asian and African-Caribbean men compared with Europeans. This study investigates (1) the association between mid-life sleep quality and later-life type 2 diabetes risk and (2) the potential modifying effect of ethnicity.

Methods

The Southall and Brent REvisited cohort is composed of Europeans, South-Asians and African-Caribbeans (median follow-up 19 years). Complete-case analysis was performed on 2189 participants without diabetes at baseline (age=51.7±7 SD). Competing risks regressions were used to estimate the HRs of developing diabetes associated with self-reported baseline sleep (difficulty falling asleep, early morning waking, waking up tired, snoring and a composite sleep score), adjusting for confounders. Modifying effects of ethnicity were analysed by conducting interaction tests and ethnicity-stratified analyses.

Results

There were 484 occurrences of incident type 2 diabetes (22%). Overall, there were no associations between sleep exposures and diabetes risk. Interaction tests suggested a possible modifying effect for South-Asians compared with Europeans for snoring only (p=0.056). The ethnicity-stratified analysis found an association with snoring among South-Asians (HR 1.41, 95% CI 1.08 to 1.85), comparing those who snored often/always versus occasionally/never. There were no elevated risks for the other sleep exposures.

Conclusion

The association between snoring and type 2 diabetes appeared to be modified by ethnicity, and was strongest in South-Asians.

Hypoxia-inducible factors and obstructive sleep apnea

Intermittent hypoxia (IH) is a hallmark manifestation of obstructive sleep apnea (OSA), a widespread disorder of breathing. This Review focuses on the role of hypoxia-inducible factors (HIFs) in hypertension, type 2 diabetes (T2D), and cognitive decline in experimental models of IH patterned after O2 profiles seen in OSA. IH increases HIF-1α and decreases HIF-2α protein levels. Dysregulated HIFs increase reactive oxygen species (ROS) through HIF-1-dependent activation of pro-oxidant enzyme genes in addition to reduced transcription of antioxidant genes by HIF-2. ROS in turn activate chemoreflex and suppress baroreflex, thereby stimulating the sympathetic nervous system and causing hypertension. We also discuss how increased ROS generation by HIF-1 contributes to IH-induced insulin resistance and T2D as well as disrupted NMDA receptor signaling in the hippocampus, resulting in cognitive decline.

Longterm effects of rotational night shift work on expression of circadian genes and its association with postprandial triglyceride levels - A pilot study

Abnormalities of lipid metabolism in the form of high fasting as well as postprandial triglyceride levels immediately after night shift work and under simulated night shift conditions have been reported in the literature. Whether dysregulation of circadian genes in the long term is associated with abnormal triglyceride metabolism has not been previously investigated. This pilot study aimed to investigate the long-term effect of rotational night shift work on the expression of circadian genes among healthcare workers and to ascertain the association between the expression of circadian genes and postprandial triglyceride and insulin resistance parameters. The study was conducted on two groups of healthcare workers (n = 20/group). Group 1 included day shift workers who had not done night shift duty during the past one year or ever. Group 2 included healthcare workers doing rotational night shift duties (≥4 night shift duties/month). Fasting blood samples were collected at 08:00 h to study the expression of circadian genes CLOCK, NPAS2, BMAL1, CRY1, CRY2, PER1, PER2, PER3, REVERBα, and biochemical parameters after which a standardized fat challenge test was done to measure postprandial triglyceride levels. Study of Group 2 individuals was conducted after a minimum of one week after the last night shift duty. Expression of CLOCK, NPAS2, PER1, PER3, and REV-ERBα genes was higher in Group 2 compared to Group 1 subjects, and expression of BMAL1 and CRY1 genes were lower in Group 2 compared to Group 1. Several of these genes showed significant correlations with postprandial triglyceride and insulin resistance parameters in Group 2 but not in Group 1 subjects. The present study showed altered expression of several circadian genes in healthcare workers involved in rotational night shift duties associated with postprandial triglyceride and insulin resistance parameters. This study therefore suggests that long term circadian gene dysregulation could have serious metabolic consequences in individuals engaged in rotational night shift duties.

Obstructive sleep apnoea increases lipolysis and deteriorates glucose homeostasis in patients with type 2 diabetes mellitus

Obstructive sleep apnoea (OSA) is associated with type 2 diabetes mellitus (T2DM). However, mechanisms mediating association between these two conditions remain unclear. This study investigated, whether the OSA-associated changes in adipose tissue lipolysis might contribute to impaired glucose homeostasis in patient with T2DM. Thirty-five matched subjects were recruited into three groups: T2DM + severe OSA (T2DM + OSA, n = 11), T2DM with mild/no OSA (T2DM, n = 10) and healthy controls (n = 14). Subcutaneous abdominal adipose tissue microdialysis assessed spontaneous, epinephrine- and isoprenaline-stimulated lipolysis. Glucose metabolism was assessed by intravenous glucose tolerance test. Spontaneous lipolysis was higher in the T2DM + OSA compared with the T2DM (60.34 ± 23.40 vs. 42.53 ± 10.16 μmol/L, p = 0.013), as well as epinephrine-stimulated lipolysis (236.84 ± 103.90 vs. 167.39 ± 52.17 µmol/L, p < 0.001). Isoprenaline-stimulated lipolysis was unaffected by the presence of OSA (p = 0.750). The α₂ anti-lipolytic effect was decreased in T2DM + OSA by 59% and 315% compared with T2DM and controls (p = 0.045 and p = 0.007, respectively). The severity of OSA (AHI) was positively associated with spontaneous (p = 0.037) and epinephrine-stimulated (p = 0.026) lipolysis. The α₂-adrenergic anti-lipolytic effect (p = 0.043) decreased with increasing AHI. Spontaneous lipolysis was positively associated with Insulin resistance (r = 0.50, p = 0.002). Epinephrine-stimulated lipolysis was negatively associated with the Disposition index (r =  - 0.34, p = 0.048). AHI was positively associated with Insulin resistance (p = 0.017) and negatively with the Disposition index (p = 0.038). Severe OSA in patients with T2DM increased adipose tissue lipolysis, probably due to inhibition of the α₂-adrenergic anti-lipolytic effect. We suggest that dysregulated lipolysis might contribute to OSA-associated impairments in insulin secretion and sensitivity.

Circadian Patterns of Patients with Type 2 Diabetes and Obstructive Sleep Apnea

Sleep apnea, a condition that modifies sleep and circadian rhythms, is highly prevalent in patients with diabetes. However, it is not known if there is an association between sleep apnea, circadian alterations and glycemic regulation in this type of patient. Here, a polysomnographic study was carried out on 21 women and 25 men (mean age = 64.3 ± 1.46 years) with diagnoses of type 2 diabetes to detect the presence of sleep apnea. Moreover, patients wore an actigraph and a temperature sensor on the wrist for one week, to study the manifestation of the circadian rhythms. The correlations of circadian and polysomnographic variables with the severity of apnea, measured by the apnea-hypopnea index, and with glycemic dysregulation, measured by the percentage of glycated hemoglobin, were analyzed. The mean apnea-hypoapnea index of all the participants was 39.6 ± 4.3. Apnea-hypoapnea index correlated with % N1, negatively with % N3, and also the stability of the active circadian rhythm. However, no significant correlation was found between the apnea-hypopnea index and wrist temperature rhythm and glycated hemoglobin. Glycated hemoglobin levels were negatively associated with the percentage of variance explained by the wrist temperature circadian rhythm (calculated via 24 and 12 h rhythms). This association was independent of body mass index and was strongest in patients with severe apnea. In conclusion, patients with diabetes showed altered circadian rhythms associated with a poor glycemic control and this association could partially be related to the coexistence of sleep apnea.

Oral Antidiabetics and Sleep Among Type 2 Diabetes Patients: Data From the UK Biobank

Previous small-scale studies have found that oral antidiabetic therapy is associated with sleep difficulties among patients with type 2 diabetes (T2D). Here, we used data from 11 806 T2D patients from the UK Biobank baseline investigation to examine the association of oral antidiabetic therapy with self-reported difficulty falling and staying asleep and daily sleep duration. As shown by logistic regression adjusted for, e.g., age, T2D duration, and HbA_1c, patients on non-metformin therapy (N=815; 86% were treated with sulphonylureas) had a 1.24-fold higher odds ratio of reporting regular difficulty falling and staying asleep at night compared to those without antidiabetic medication use (N=5 366, P<0.05) or those on metformin monotherapy (N=5 625, P<0.05). Non-metformin patients reported about 8 to 10 minutes longer daily sleep duration than the other groups (P<0.05). We did not find significant differences in sleep outcomes between untreated and metformin patients. Our findings suggest that non-metformin therapy may result in sleep initiation and maintenance difficulties, accompanied by a small but significant sleep extension. The results of the present study must be replicated in future studies using objective measures of sleep duration and validated questionnaires for insomnia. Considering that most T2D patients utilize multiple therapies to manage their glycemic control in the long term, it may also be worth investigating possible interactions of antidiabetic drugs on sleep.

Rationale and design of the Hyperglycemic Profiles in Obstructive Sleep Apnea (HYPNOS) trial

The Hyperglycemic Profiles in Obstructive Sleep Apnea (HYPNOS) randomized clinical trial was conducted in adults with type 2 diabetes and moderate-to-severe obstructive sleep apnea (OSA) to determine whether treatment with positive airway pressure (PAP) therapy is associated with improvements in glycemic measures. Participants were randomly assigned to PAP therapy with lifestyle counseling or lifestyle counseling alone. While observational and experimental evidence indicate that intermittent hypoxemia and recurrent arousals in OSA may alter glucose metabolism and worsen glycemic measures, the effect of treating OSA with PAP therapy on these measures in type 2 diabetes is uncertain. Adequately powered randomized clinical trials have yet to be performed to demonstrate whether PAP therapy for OSA in patients with type 2 diabetes can improve glycemic measures. The HYPNOS trial was designed to determine whether PAP therapy for OSA in patients with type 2 diabetes over 3 months leads to improvements in glycemic measures including glycemic variability (standard deviation) based on Dexcom G4 Platinum continuous glucose monitoring. Secondary objectives were to assess the effects of PAP therapy for OSA on measures of: (1) glycemic variability based on Abbott Freestyle Pro Libre continuous glucose monitoring; (2) point-of-care hemoglobin A1c (HbA1c); (3) degree of post-prandial hyperglycemia as determined by 7-point self-monitoring of blood glucose; (4) clinic and ambulatory blood pressure; and (5) endothelial function. The HYPNOS trial was designed to address gaps in our understanding of the effects of PAP therapy on glucose metabolism in adults with type 2 diabetes and moderate-to-severe OSA. Trial Registration: ClinicalTrials.gov Identifier NCT02454153.

The effect of intermittent hypoxia and fecal microbiota of OSAS on genes associated with colorectal cancer

Purpose

Colorectal cancer (CRC) is one of the common causes of cancer death worldwide. Obstructive sleep apnea syndrome (OSAS), sharing many risk factors in common with CRC, is prevalent among CRC patients. OSAS may promote the CRC development independently but the mechanism is still unknown. Intermittent hypoxia (IH) is one of the characteristics of OSAS, and hypoxia may influence the genes associated with CRC. Intestinal microbiota plays important role in CRC carcinogenesis, and OSAS patients have been shown to have intestinal microbiota dysbiosis. We hypothesized that IH and intestinal microbiota dysbiosis may be involved for CRC in patients with OSAS.

Methods

We established precancerous cell models of CRC with Immorto-Min colonic epithelial (IMCE) cells. First, the cells were exposed to IH in a special chamber for 4 h, 8 h, and 12 h. Feces from 6 patients with OSAS and 6 healthy controls were collected and made into sterile fecal fluid for incubation with IMCE cells for 12 h. The cells were then exposed to IH for 4 h, 8 h, and 12 h. After IH exposure, the expressions of genes and inflammation cytokines associated with CRC, such as β-catenin, STAT3, HIF-1α, IL-6, TNF-α, c-myc, and cyclinD1, were tested.

Results

IH activated the expression of HIF-1α and STAT3 both in mRNA and protein level (HIF-1α: P = 0.015 for mRNA level, P = 0.027 for protein level; STAT3: P = 0.023 for mRNA level, P = 0.023 for protein level), and promoted p-STAT3 shifting to the nucleus (P = 0.023). The mRNA of β-catenin (P = 0.022) and cyclinD1 (P = 0.023) was elevated, but there was no change for the β-catenin protein in the nucleus. Gut microbiota of OSAS patients promoted the expression of STAT3 (protein level: 0 h: P = 0.037; 4 h: P = 0.046; 8 h: P = 0.049; 12 h: P = 0.037), promoted p-STAT3 (4 h: P = 0.049; 8 h: P = 0.046; 12 h: P = 0.046) shifting to the nucleus, and also elevated the expression of IL-6 and TNF-α in mRNA level at 4 h (IL-6: P = 0.037, TNF-α: P = 0.037) and 8 h (IL-6: P = 0.037, TNF-α: P = 0.037). The protein of β-catenin in the nucleus was not affected by IH and gut microbiota from OSAS.

Conclusions

Our study demonstrated that IH and gut microbiota of patients with OSAS activated HIF-1α expression and STAT3 pathway in IMCE cells, with no influence on β-catenin pathway, which suggested that IH, STAT3 pathway, chronic inflammation, and intestinal microbiota dysbiosis may be involved in CRC carcinogenesis correlated with OSAS These findings must be interpreted cautiously and further research is necessary to clarify the causative steps in CRC development.

Eating Fast Is Associated with Nonalcoholic Fatty Liver Disease in Men But Not in Women with Type 2 Diabetes: A Cross-Sectional Study

Non-alcoholic fatty liver disease (NAFLD), often complicated by type 2 diabetes mellitus (T2DM), is reported to be associated with diet habits, including eating speed, in the general population. However, the association between eating speed and NAFLD in patients with T2DM, especially sex difference, has not been reported so far. This cross-sectional study included 149 men and 159 women with T2DM. Eating speed was evaluated by a self-reported questionnaire and divided into three groups: fast, moderate, and slow eating. Nutrition status was evaluated by a brief-type self-administered diet history questionnaire. NAFLD was defined as the hepatic steatosis index ≥36 points. Body mass index and carbohydrate/fiber intake in the fast-eating group were higher than those in the slow-eating group in men, whereas this difference was absent in women. In men, compared with eating slowly, eating fast had an elevated risk of the presence of NAFLD after adjusting for covariates (odds ratio (OR) 4.48, 95% confidence interval (CI) 1.09–18.5, p = 0.038). In women, this risk was not found, but fiber intake was found to be negatively associated with the presence of NAFLD (OR 0.85, 95% Cl 0.76–0.96, p = 0.010). This study indicates that eating speed is associated with the presence of NAFLD in men but not in women.

Association of Sleep Apnea with Mortality in Patients with Advanced Kidney Disease

BACKGROUND AND OBJECTIVES

In the general population, sleep disorders are associated with mortality. However, such evidence in patients with CKD and ESKD is limited and shows conflicting results. Our aim was to examine the association of sleep apnea with mortality among patients with CKD and ESKD.

DESIGN, SETTING, PARTICIPANTS, & MEASUREMENTS

In this prospective cohort study, 180 patients (88 with CKD stage 4 or 5, 92 with ESKD) underwent in-home polysomnography, and sleep apnea measures such as apnea hypopnea index (AHI) and nocturnal hypoxemia were obtained. Mortality data were obtained from the National Death Index. Cox proportional hazard models were used for survival analysis.

RESULTS

Among the 180 patients (mean age 54 years, 37% women, 39% with diabetes, 49% CKD with mean eGFR 18±7 ml/min per 1.73 m²), 71% had sleep apnea (AHI>5) and 23% had severe sleep apnea (AHI>30). Median AHI was 13 (range, 4-29) and was not significantly different in patients with advanced CKD or ESKD. Over a median follow-up of 9 years, there were 84 (47%) deaths. AHI was not significantly associated with mortality after adjusting for age, sex, race, diabetes, body mass index, CKD/ESKD status, and kidney transplant status (AHI>30: hazard ratio [HR], 1.5; 95% confidence interval [95% CI], 0.6 to 4.0; AHI >15 to 30: HR, 2.3; 95% CI, 0.9 to 5.9; AHI >5 to 15: HR, 2.1; 95% CI, 0.8 to 5.4, compared with AHI≤5). Higher proportion of sleep time with oxygen saturation <90% and lower mean oxygen saturation were significantly associated with higher mortality in adjusted analysis (HR, 1.4; 95% CI, 1.1 to 1.7; P=0.007 for every 15% higher proportion, and HR, 1.6; 95% CI, 1.2 to 2.1; P=0.003 for every 2% lower saturation, respectively). Sleep duration, sleep efficiency, or periodic limb movement index were not associated with mortality.

CONCLUSIONS

Hypoxemia-based measures of sleep apnea are significantly associated with increased risk of death among advanced CKD and ESKD.

A New Hypothesis on Anxiety, Sleep Insufficiency, and Viral Infections; Reciprocal Links to Consider in Today's "World vs. COVID-19" Endeavors

In today's ever-growing concerns about the coronavirus disease (COVID-19) pandemic, many experience sleep insufficiencies, such as difficulty falling or staying asleep, sleep-related behavioral symptoms, and out-of-phase circadian rhythmicity despite the lack of history of earlier such symptoms. Meanwhile, the disruption in sleep bioparameters is experienced more in people with a history of sleep disorders. The behavioral sleep disorders in the current situations are prevalent given the today's amount of anxiety everyone is feeling about COVID-19. On the other hand, evidences indicated that the cross-link between impaired sleep efficiency and disrupted innate immunity makes people susceptible to viral infections. The present brief review highlights the links between psychosocial stress, sleep insufficiency, and susceptibility to viral infections in relevance to COVID-19 situation. The stress management measures, including addressing sleep-related disorders and sleep hygiene, will have a notable impact by harnessing immune response and thus reducing the susceptibility to viral infections.

Obstructive Sleep Apnoea in Pakistan: A Single Tertiary Care Center Experience

INTRODUCTION

Considerable interest has been shown in the field of sleep medicine in recent decades. Obstructive sleep apnoea (OSA) is a common condition that remains neglected in most parts of the world. Data are scarce, if any, when it comes to developing countries. We sought to describe the patient population in a single private tertiary care center from such a country.

MATERIALS AND METHODS

A cross-sectional study that included a total of 203 patients over a five-year period was conducted. Polysomnographic studies were conducted in a dedicated sleep laboratory, under the supervision of sleep physicians. Data were described and analyzed based on clinical and self-reported outcomes, as well as polysomnographic characteristics, and compared them between genders and severity.

RESULTS

With the participants having an average age of 50.84 years and a BMI of 34.7 kg/m², the study found that the increase in age and BMI was significantly correlated with an increase in the severity of obstructive sleep apnea in the Pakistani population. There was a significant difference in sleep latency (20.6 min in women vs. 10.8 min in men; p-value = 0.001) and efficiency (63.7% in women vs. 69.8 in men; p-value = 0.02) between the two genders. Decreases in nadir saturation, total sleep time, and sleep latency were also associated with an increase in the level of severity.

CONCLUSION

There is a dire need for Pakistani, and in extension Asian, medical professionals to ramp up their pace to meet the needs of their population with regard to sleep medicine.

Explorating the Involvement of Plasma Sestrin2 in Obstructive Sleep Apnea

Obstructive sleep apnea (OSA) can lead to serious complications such as coronary heart disease and hypertension due to oxidative stress. Sestrin2 expression is upregulated under conditions of oxidative stress. This study aimed to explore whether Sestrin2 was involved in OSA. OSA and healthy control subjects were recruited and matched with age, gender, and body mass index (BMI). Plasma Sestrin2 levels were measured and compared. A multivariate stepwise regression model was used to detect the relationship between Sestrin2 and other variable factors. The Sestrin2 levels were compared between before and after four weeks treatment by nasal continuous positive airway pressure (nCPAP) in severe OSA patients. Fifty-seven subjects were divided into two groups: control group (39.33 ± 9.40 years, n = 21) and OSA group (38.81 ± 7.84 years, n = 36). Plasma Sestrin2 levels increased in the OSA group (control group 2.06 ± 1.76 ng/mL, OSA group 4.16 ± 2.37 ng/mL; P = 0.001). Sestrin2 levels decreased after four-week nCPAP treatment (pre-nCPAP 5.21 ± 2.32 ng/mL, post-nCPAP 4.01 ± 1.54 ng/mL; P = 0.004). Sestrin2 was positively correlated with apnea/hypopnea index (AHI) oxygen desaturation index, while negatively correlated with mean oxygen saturation. Moreover, these correlations remained unchanged after adjusting for gender, age, waist-to-hip ratio, and body mass index. Multiple regression analysis showed that there was an association between Sestrin2 and AHI. Our findings suggest that Sestrin2 is involved in OSA. The increase of plasma Sestrin2 is directly related to the severity of OSA. To some extent, Sestrin2 may be useful for determining the severity of OSA and monitoring the effect of CPAP. In addition, since some complications of OSA such as coronary heart disease and diabetes are usually related with oxidative stress, the role of Sestrin2 in those OSA complications needs further study.

Relationship Between Intermittent Hypoxia and Type 2 Diabetes in Sleep Apnea Syndrome

Sleep apnea syndrome (SAS) is a very common disease involving intermittent hypoxia (IH), recurrent symptoms of deoxygenation during sleep, strong daytime sleepiness, and significant loss of quality of life. A number of epidemiological researches have shown that SAS is an important risk factor for insulin resistance and type 2 diabetes mellitus (DM), which is associated with SAS regardless of age, gender, or body habitus. IH, hallmark of SAS, plays an important role in the pathogenesis of SAS and experimental studies with animal and cellular models indicate that IH leads to attenuation of glucose-induced insulin secretion from pancreatic β cells and to enhancement of insulin resistance in peripheral tissues and cells, such as liver (hepatocytes), adipose tissue (adipocytes), and skeletal muscles (myocytes). In this review, we focus on IH-induced dysfunction in glucose metabolism and its underlying molecular mechanisms in several cells and tissues related to glucose homeostasis.

Sleep-Disordered Breathing and Peripheral Arterial Disease: Current Evidence

INTRODUCTION

Sleep-disordered breathing (SDB) is associated with atherosclerosis. Peripheral arterial disease (PAD) is a manifestation of atherosclerosis in lower extremity arteries. No systematic review addressing the relationship between PAD and SDB was found. We performed this study aimed to summarize the relationship between SDB and PAD described in current clinical studies.

MATERIAL AND METHODS

PubMed and Embase electronic databases were searched for clinical articles (published before 3 April, 2019) describing studies that evaluated the association between SDB and PAD. We showed the results involved in the association in clinical studies.

RESULTS

In total, 8 clinical studies have been included, and most of them were cross-sectional studies. Six articles demonstrated the coexistence of SDB and PAD, evidenced by high prevalence of SDB in patients with PAD and vice versa. Meanwhile, the included studies exhibited independent positive associations between SDB or sleep parameters and PAD after adjusting for multiple confounders.

CONCLUSION

From present clinical prospective, positive association between SDB and PAD was shown. More prospective, randomized controlled studies are needed to establish the cause-effect relationships involved.

Active Time-Restricted Feeding Improved Sleep-Wake Cycle in db/db Mice

People with diabetes are more likely to experience sleep disturbance than those without. Sleep disturbance can cause daytime sleepiness in diabetic patients, which may impair their daytime performance or even lead to workplace injuries. Therefore, restoring the normal sleep-wake cycle is critical for diabetic patients who experience daytime sleepiness. Previous data on a diabetic mouse model, the db/db mice, have demonstrated that the total sleep time and sleep fragmentation are increased and the daily rhythm of the sleep-wake cycle is attenuated. Accumulating evidence has shown that active time-restricted feeding (ATRF), in which the timing of food availability is restricted to the active-phase, is beneficial to metabolic health. However, it is unknown whether ATRF restores the normal sleep-wake cycle in diabetes. To test that, we used a non-invasive piezoelectric system to monitor the sleep-wake profile in the db/db mice with ad libitum feeding (ALF) as a baseline and then followed with ATRF. The results showed that at baseline, db/db mice exhibited abnormal sleep-wake patterns: the sleep time percent during the light-phase was decreased, while during the dark-phase it was increased with unusual cycling compared to control mice. In addition, the sleep bout length during both the light-phase and the full 24-h period was shortened in db/db mice. Analysis of the sleep-wake circadian rhythm showed that ATRF effectively restored the circadian but suppressed the ultradian oscillations of the sleep-wake cycle in the db/db mice. In conclusion, ATRF may serve as a novel strategy for treating diabetes-induced irregularity of the sleep-wake cycle.

Prevalence of obstructive sleep apnea in patients with type 2 diabetes: A systematic review and meta-analysis

Obstructive sleep apnea (OSA) is highly prevalent among patients with diabetes, intensifying the complications of the disease. Various studies in Iran have reported different prevalence rates. This systematic review and meta-analysis was performed to determine OSA prevalence in patients with type 2 diabetes in Iran. In this study, we evaluated five articles published in Persian and English. The articles were searched using the keywords of obstructive sleep apnea, sleep disordered breathing, sleep apnea, OSA, diabetes mellitus and Iran and all possible combinations of these terms in national databases of Scientific Information Database (SID) and Magiran and international databases of Google Scholar, Web of Science, PubMed and Scopus with no time limit. Data were analyzed using the meta-analysis and random effects model. In addition, the heterogeneity between studies was assessed using I² statistic, and data analysis was performed in Stata version 11. In this study, five articles with a total sample size of 2360 were evaluated. According to the results, the prevalence of OSA in diabetic patients was reported to be 54.50% (95% Confidence Interval [CI]: 39.90-69.09). In addition, the results were indicative of a lower prevalence of OSA in men (63.26%; 95% CI: 43.26-83.26), compared to women (66.22%; 95% CI: 57.60-74.84). According to the results of the study, there was a high OSA prevalence in patients with type 2 diabetes. Therefore, it is crucial to recognize diabetic patients at risk of OSA to decrease the adverse effects of this condition.

The prevalence of high risk obstructive sleep apnoea among patients with type 2 diabetes in Jordan

OBJECTIVE

To estimate the prevalence of Obstructive Sleep Apnea (OSA) among patients with type 2 Diabetes Mellitus (T2DM) in Jordan, and to explore the association between sleep apnea and clinical and demographic variables.

METHOD

A cross-sectional study was carried out from the 1st of November 2011 to the 1st of February 2012 on 1143 patients with T2DM (aged 30-90 years) at the National Center for Diabetes, Endocrinology, and Genetics (NCDEG). The center is considered to be the only referral center in the country and accordingly, the patients represent the population in different parts of the country. All participants completed the Arabic version of the Berlin Questionnaire and were categorized as either low or high-risk patients for OSA.

RESULTS

A total of 1143 patients with T2DM were included in this study. There were 587 (51.4%) males and 556 (48.6%) females. The findings showed that 554 (48.5%) patients were at high risk for OSA and 589 (51.5%) were low risk for OSA. Logistic regression analysis revealed that age, smoking, and neck circumference were significantly correlated with high risk for OSA. The clinical and demographic variables were also collected for analysis.

CONCLUSIONS

The study found that high risk for OSA was highly prevalent among Jordanian patients with T2DM and that age, smoking and neck circumference were significantly correlated with OSA. Health care providers should be made aware of the high prevalence of sleep problems affecting patients with diabetes and should consider the appropriate screening and treatment for these patients, therefore improving their quality of life.

The Interlinked Rising Epidemic of Insufficient Sleep and Diabetes Mellitus

For healthy existence, humans need to spend one-third of their time sleeping. Any qualitative or quantitative disturbances in sleep would result in an increased prevalence of obesity, metabolic disorders, diabetes, cardiovascular diseases, and hypertension. The paper aims to highlight the growing global problem of insufficient sleep and its significant impact on the rising incidence of diabetes mellitus. An extensive literature search was done in all major databases for "insufficient sleep" and "Diabetes Mellitus" for this review. Shorter (<6 h) and longer (>9 h) durations of sleep have been adversely related to insulin resistance. Though the relation between insufficient sleep and diabetes mellitus is more or less understood, little is known about how oversleeping or hypersomnia (10⁻12 h) increases the risk of diabetes. The relationship between sleep disturbances and diabetes is dual-sided, as chronic sleep disturbances would elevate the risk of developing insulin resistance, while diabetes would worsen the quality of sleep. Both the qualitative and quantitative disturbances in sleep significantly increase the risk of developing diabetes, which is supported by numerous community-based and hospital-based epidemiological studies discussed in this review. Obstructive sleep apnea is one of the most common sleep disorders and is characterized by chronic intermittent hypoxia and increased sympathetic activity, thus leading to a higher prevalence of diabetes. Sleep therapy may serve as a low-cost method for fighting against the rising epidemic of diabetes.

Obstructive sleep apnea affects complication rates following knee arthroscopy but use of continuous positive airway pressure is not protective against complications

PURPOSE

Obstructive sleep apnea (OSA) has not been studied as a risk factor for complications following knee arthroscopy. The goals of this study were to: (1) compare complication rates after knee arthroscopy between patients with and without OSA and (2) evaluate whether continuous positive airway pressure (CPAP) mitigated complication rates.

METHODS

A national private insurance database was queried for patients undergoing simple knee arthroscopy from 2007 to 2016. Patients with a diagnosis of OSA were then identified using ICD-9/10 codes. Patients with OSA were then subdivided into cohorts with and without a billing code for a CPAP device. Adverse events within 30 days postoperatively related to OSA were then assessed in all groups: (1) emergency room (ER) visit, (2) hospital admission, (3) pulmonary embolism (PE), (4) myocardial infarction, (5) respiratory arrest and (6) in-hospital mortality within 6 months postoperatively. Adverse event rates were compared between the control and study groups using a multivariable regression analysis.

RESULTS

97,036 patients underwent simple knee arthroscopy with 8656 patients having a diagnosis of OSA. Of these, 3820 (44%) had orders for CPAP machines. After controlling for confounders, patients with OSA had significantly higher risk of ER visits, PE and respiratory arrest compared to controls (p < 0.05). The majority of these significant findings persisted regardless of CPAP use. There were no significant differences in complication rates between OSA patients with and without CPAP orders.

CONCLUSIONS

OSA appears to be independently associated with a higher risk for ER visits, PE and respiratory arrest following knee arthroscopy after controlling for demographic and comorbidity confounders. An order for CPAP was not associated with a significant reduction the risk for these complications. CPAP noncompliance may not be as important a factor when risk stratifying patients undergoing ambulatory knee arthroscopy compared to more significant medical comorbidities.

LEVEL OF EVIDENCE

III.

Intermittent hypoxia promotes carcinogenesis in azoxymethane and dextran sodium sulfate-induced colon cancer model

Intermittent hypoxia (IH), a characteristic of obstructive sleep apnea, is known to promote cancer progression and aggressiveness in mouse models. However, little is known regarding the effect of IH on cancer initiation. Here, the effect of IH on carcinogenesis was explored in azoxymethane (AOM) and dextran sodium sulfate (DSS)-induced colon cancer models with three different protocols. In the first protocol, two other application time points (early or late initiation of IH) were applied. In the second protocol, mice were divided into only two groups, and then exposed to either N or IH conditions for 14 days. In the third protocol, a pharmacological inhibition study for anti-inflammation (5-aminosalicylate) or anti-oxidative stress (N-acetylcysteine [NAC]) was performed. The number of tumors was significantly higher in the IH-1 than in the N or IH-2 groups. 8-oxo-2'-deoxyguanosine (8-OHdG) levels were higher in tumors of the IH-1 group than in that of the N and IH-2 groups. Gene expression related to reactive oxygen species production was higher in the IH-1 group than in the N and IH-2 groups, and it showed a positive correlation with 8-OHdG levels. Prior to cancer development 8-OHdG levels were already elevated in colonic epithelial regions in the IH group, possibly due to an imbalance between oxidative stress and antioxidant systems. NAC treatment resulted in a significant reduction in the number of tumors in mice exposed to IH. In conclusion, IH promotes carcinogenesis in a chemically-induced colon cancer model where elevated 8-OHdG may contribute to the increased tumor induction.

Evaluation of obstructive sleep apnea in metabolic syndrome

Background:

Metabolic syndrome has become one of the most important public health problems with a growing prevalence in both developed and developing countries. Obesity is a major risk factor for obstructive sleep apnea (OSA), which is associated with significant cardiorespiratory morbidity.

Aims:

The aims of this study were to find out the prevalence of OSA in patients with metabolic syndrome and to highlight the importance of assessment of OSA in these patients.

Methods:

This cross-sectional analytical study was conducted on 100 subjects aged 30–60 years, comprising 50 cases of metabolic syndrome and 50 controls without metabolic syndrome. Overnight polysomnography was done in all the subjects. Prevalence and severity of OSA were assessed and compared between the two groups.

Results:

Prevalence of OSA was significantly higher (66%) in patients with metabolic syndrome than in subjects without metabolic syndrome (12%). Out of 33 (66%) OSA patients with metabolic syndrome, 8 (16%) had mild OSA, 11 (22%) had moderate OSA, and 14 (28%) had severe OSA. Increasing severity of OSA was associated with higher mean levels of all the metabolic syndrome parameters except serum high density lipoprotein (HDL).

Conclusions:

OSA is highly prevalent in patients with metabolic syndrome. Also, the increasing severity of OSA is associated with poorer control of diabetes, hypertension, and dyslipidemia, which are all components of metabolic syndrome. Therefore, effective treatment of metabolic syndrome can prevent and control OSA in these patients. Similarly, reducing the severity of OSA (by early diagnosis and treatment) in patients with metabolic syndrome might help to optimize control of blood sugar, blood pressure, and serum lipids, thereby reducing the risk of cardiovascular disease. Therefore, the need for screening metabolic syndrome patients for OSA has been reinforced by this study.

Clinical significance of obstructive sleep apnea in patients with acute coronary syndrome in relation to diabetes status

OBJECTIVE

The prognostic significance of obstructive sleep apnea (OSA) in patients with acute coronary syndrome (ACS) according to diabetes mellitus (DM) status remains unclear. We aimed to elucidate the association of OSA with subsequent cardiovascular events in patients with ACS with or without DM.

RESEARCH DESIGN AND METHODS

In this prospective cohort study, consecutive eligible patients with ACS underwent cardiorespiratory polygraphy between June 2015 and May 2017. OSA was defined as an Apnea Hypopnea Index ≥15 events/hour. The primary end point was major adverse cardiovascular and cerebrovascular events (MACCEs), including cardiovascular death, myocardial infarction, stroke, ischemia-driven revascularization, or hospitalization for unstable angina or heart failure.

RESULTS

Among 804 patients, 248 (30.8%) had DM and 403 (50.1%) had OSA. OSA was associated with 2.5 times the risk of 1 year MACCE in patients with DM (22.3% vs 7.1% in the non-OSA group; adjusted HR (HR)=2.49, 95% CI 1.16 to 5.35, p=0.019), but not in patients without DM (8.5% vs 7.7% in the non-OSA group, adjusted HR=0.94, 95% CI 0.51 to 1.75, p=0.85). Patients with DM without OSA had a similar 1 year MACCE rate as patients without DM. The increased risk of events was predominately isolated to patients with OSA with baseline glucose or hemoglobin A1c levels above the median. Combined OSA and longer hypoxia duration (time with arterial oxygen saturation <90%>22 min) further increased the MACCE rate to 31.0% in patients with DM.

CONCLUSIONS

OSA was associated with increased risk of 1 year MACCE following ACS in patients with DM, but not in non-DM patients. Further trials exploring the efficacy of OSA treatment in high-risk patients with ACS and DM are warranted.