Evaluation of Inflammatory Markers in a Large Sample of Obstructive Sleep Apnea Patients without Comorbidities

Evaluation of Serum/Plasma Levels of Interleukins (IL-6, IL-12, IL-17, IL-18, and IL-23) in Adults and Children with Obstructive Sleep Apnea: A Systematic Review, Meta-Analysis, and Trial Sequential Analysis

Obstructive sleep apnea (OSA) is a chronic inflammatory disease characterized by partial or complete upper airway obstruction during sleep. We aimed to evaluate serum/plasma levels of several cytokines (interleukin [IL]-6, IL-12, IL-17, IL-18, and IL-23) in a systematic review meta-analysis in both adults and children with OSA compared with controls. We conducted a comprehensive search of 4 digital databases (PubMed, Web of Science, Scopus, and Cochrane Library) up until October 19, 2023, without any limitations. For our meta-analysis, we used Review Manager, version 5.3, and displayed the data as the standardized mean difference (SMD) and 95% confidence interval (CI) to assess the correlation between cytokine levels and OSA. We utilized Comprehensive Meta-Analysis version 3.0 software to conduct bias analyses, meta-regression, and sensitivity analyses. From 1881 records, 84 articles were included in the systematic review and meta-analysis. In adults, the pooled SMDs for IL-6 level were 0.79 (P value < 0.00001), for IL-17 level were 0.74 (P value = 0.14), and for IL-18 level were 0.43 (P value = 0.00002). In children, the pooled SMD for IL-6 was 1.10 (P value < 0.00001), for IL-12 was 0.47 (P value = 0.10), for IL-17 was 2.21 (a P value = 0.24), for IL-18 was 0.19 (P value = 0.07), and for IL-23 was 2.46 (P value < 0.0001). The subgroup analysis showed that the ethnicity, mean body mass index, and mean apnea-hypopnea index for IL-6 levels in adults and the ethnicity for IL-6 levels in children were effective factors in the pooled SMD. The findings of the trial sequential analysis revealed that adequate evidence has been obtained. The analysis of IL levels in adults and children with OSA compared with those without OSA revealed significant differences. In adults, IL-6 and IL-18 levels were significantly higher in the OSA group, while in children, only IL-6 and IL-23 levels were significantly elevated.

Effects of Obstructive Sleep Apnea on Airway Immunity and Susceptibility to Respiratory Infections

Obstructive sleep apnea is a prevalent sleep disorder characterized by recurrent episodes of partial or complete upper airway collapse during sleep, leading to disrupted breathing patterns and intermittent hypoxia. OSA results in systemic inflammation but also directly affects the upper and lower airways leading to upregulation of inflammatory pathways and alterations of the local microbiome. These changes result in increased susceptibility to respiratory infections such as influenza, COVID-19, and bacterial pneumonia. This relationship is more complex and bidirectional in individuals with chronic lung disease such as chronic obstructive lung disease, interstitial lung disease and bronchiectasis.

Clinical outcomes of obstructive sleep apnea in patients with acute coronary syndrome in relation to hyperuricemia status

The clinical outcome of obstructive sleep apnea in patients with acute coronary syndrome in relation to hyperuricemia is still unclear. We aimed to explore the clinical prognosis of obstructive sleep apnea in patients with acute coronary syndrome in relation to hyperuricemia status. This was a prospective cohort study. We included consecutively eligible patients with acute coronary syndrome who underwent cardiorespiratory polygraphy between June 2015 and January 2020. According to apnea-hypopnea index ≥ 15 events per hr and serum uric acid level, the population was divided into four groups: hyperuricemia with obstructive sleep apnea; hyperuricemia with non-obstructive sleep apnea; no hyperuricemia with obstructive sleep apnea; and no hyperuricemia with non-obstructive sleep apnea. The primary endpoint was major adverse cardiovascular and cerebrovascular events, including cardiovascular death, myocardial infarction, stroke, ischaemia-driven revascularization, and readmission for unstable angina or heart failure. Spearman correlation analysis and Cox regression model were mainly used to estimate the data. The median follow-up was 2.9 years. Among 1925 patients with acute coronary syndrome, 29.6% had hyperuricemia and 52.6% had obstructive sleep apnea. Uric acid was negatively correlated with minimum arterial oxygen saturation and mean arterial oxygen saturation, and positively correlated with apnea-hypopnea index, oxygen desaturation index and the duration of time with arterial oxygen saturation < 90% (p < 0.001). During 2.9 (1.5, 3.6) years of follow-up, obstructive sleep apnea was associated with an increased risk of major adverse cardiovascular and cerebrovascular events in patients with hyperuricemia (23.5% versus 13.4%; adjusted hazard ratio: 1.834; 95% confidence interval: 1.192-2.821, p = 0.006), but not in patients without hyperuricemia (21.9% versus 19.2%; adjusted hazard ratio: 1.131; 95% confidence interval: 0.880-1.453, p = 0.336). There was a correlation between uric acid levels and sleep respiratory indicators. Obstructive sleep apnea was associated with increased risk of major adverse cardiovascular and cerebrovascular events in patients with acute coronary syndrome with hyperuricemia, but not in patients without hyperuricemia.

Relationship Between Hyperuricemia-Waist Phenotype and Obstructive Sleep Apnea in Type 2 Diabetes Mellitus

Objective

This study aimed to propose the hyperuricemia-waist (HUAW) phenotype and investigate the relationship between the HUAW phenotype and obstructive sleep apnea (OSA) in type 2 diabetes mellitus (T2DM).

Methods

We enrolled 255 patients with T2DM (165 male and 90 female) from the First Hospital of Qinhuangdao. The sleep test was performed, and serum uric acid (UA) levels and waist circumference (WC) were calculated. The HUAW phenotype was defined as serum UA concentrations ≥420 μmol/L and WC ≥90 cm (male) and ≥85 cm (female). The participants were categorized into four phenotype groups based on the mentioned cutoffs: normal WC and normal UA concentrations (group A); normal WC and elevated UA concentrations (group B); enlarged WC and normal UA concentrations (group C); and enlarged WC and elevated UA concentrations (group D). Among these participants, 17.6% were characterized by the HUAW phenotype, 80.0% had OSA, and 47.0% had moderate-to-severe OSA. The prevalence of OSA was 43.4%, 71.4%, 89.7%, and 97.8% in groups A, B, C, and D, respectively. The prevalence of moderate-to-severe OSA was 7.5%, 28.6%, 56.9%, and 72.7% in groups A, B, C, and D, respectively. After adjusting for age, sex, duration of diabetes, glycosylated hemoglobin A1c, smoking, and drinking, the HUAW phenotype was found to be significantly associated with OSA and moderate-to-severe OSA.

Conclusion

The present study proposed the HUAW phenotype and demonstrated that in T2DM, the HUAW phenotype was associated with OSA, especially with moderate-to-severe OSA. Unlike T2DM without the HUAW phenotype, T2DM with the HUAW phenotype showed a significantly higher prevalence of OSA, especially moderate-to-severe OSA. Thus, early sleep studies should be routinely examined in individuals with T2DM who display the HUAW phenotype.

Association Between the Severity of Obstructive Sleep Apnea and the Risk Stratification of Acute Pulmonary Embolism

Obstructive sleep apnea (OSA) has been associated with the initiation and progression of cardiovascular disease. This study aimed to explore the relationship between the severity of OSA and the risk stratification of acute pulmonary embolism (PE). In this single-center cohort study, patients diagnosed with PE were evaluated for OSA via polygraphy monitoring. The simplified PE severity index (sPESI) and the number of patients requiring systemic thrombolysis were used to determine the severity of the disease. Echocardiography was performed on all participants. All patients were divided into 2 groups (OSA group and non-OSA group), and the patients in OSA group were then divided into 3 groups based on the severity of OSA. Patients with severe OSA had a significantly higher number of patients with sPESI ≥ 1 (P = .005). A higher proportion of patients with severe OSA require systemic thrombolysis (P = .010). Patients with apnea-hypopnea index (AHI) > 30/h had a much higher fibrinogen (P = .004) and D-dimer (P = .040) level than those in the non-OSA group. The levels of creatinine were significantly higher in patients with OSA (P = .040). Echocardiography showed a significant difference in left ventricular ejection fraction (LVEF) between patients in non-OSA and severe OSA groups (P = .035). And brain natriuretic peptide (BNP) also exhibited a progressive worsening related to the deepest desaturation and oxygen desaturation index. OSA, especially with AHI > 30/h, is correlated with the severity and prognosis of acute PE. This might be attributed to the prothrombotic effect, renal impairment, and cardiac dysfunction in patients with severe OSA.

A Case-Control Study on the Changes in High-Sensitivity C-Reactive Protein and Tumor Necrosis Factor-Alpha Levels with Surgical Treatment of OSAS

Obstructive sleep apnea syndrome (OSAS) is a common but underdiagnosed condition with significant health and economic implications for society. Inflammatory mediators are proposed to be associated with the presence and severity of OSAS and contribute to morbidity and mortality. This paper details a prospective non-randomized case control study of a cohort of subjects, who underwent surgical treatment of OSAS and were enrolled to assess the sleep parameters and blood levels of selected inflammatory markers at pre-operative and post-operative time points, also comparing them to the levels in a control group. A total of 25 study subjects and 18 control subjects were enrolled. Median values and interquartile range (IQR) of the apnea-hypopnea index (AHI) in the study group pre-operatively and post-operatively were 34 (18.5-45.5) and 13.3 (7.5-27.3), while in the control group 1.4 (1.0-2.1) per hour. The mean (IQR) hs-CRP levels (mg/L) were 1.782 (0.941-5.594) and 1.980 (0.990-5.445) in the study group, pre-operatively and post-operatively, respectively, while 0.891 (0.767-1.436) in the control group. The mean (IQR) TNF-α levels (pg/mL) were 7.999 (6.137-9.216) and 6.614 (5.534-7.460) pre-and post-operatively, respectively, and were 6.000 (5.026-6.823) in the control group. Results demonstrated that both inflammatory markers, hs-CRP and TNF-α, are higher in subjects with OSAS compared to the controls, and their levels decrease, but are still higher than the controls, after successful surgical treatment. Further analysis including the body mass index and age demonstrated that these changes were significant for TNF-α, but not hs-CRP.

Association of Blood MCP-1 Levels with Risk of Obstructive Sleep Apnea: A Systematic Review and Meta-Analysis

Background and objective: Among the broad variety of chemokines, monocyte chemoattractant protein-1 (MCP-1) is considered to be one of the most important chemokines. Among others, MCP-1 activates monocytes and other immune cells highly involved in inflammation. In the present systematic review and meta-analysis, we evaluated the relationship between serum/plasma MCP-1 levels and the risk of obstructive sleep apnea (OSA) in adults as a disease related to inflammation. Materials and methods: Four databases were systematically investigated until 12 July 2022. We used the Review Manager 5.3 software (Copenhagen: The Nordic Cochrane Centre, The Cochrane Collaboration, Copenhagen, Denmark) to extract and calculate the standardized mean difference (SMD) and its 95% confidence interval (CI) of plasma/serum levels of MCP-1 between adults with and without OSA. Results: Eight articles including eleven studies in adults were entered into the meta-analysis. The serum/plasma MCP-1 levels in adults with OSA were higher than that in the controls (SMD = 0.81; p = 0.0007) and as well as for adults with severe OSA compared to those with mild and moderate OSA (SMD = 0.42; p < 0.0001). The subgroup analysis showed that ethnicity was an effective factor in the pooled analysis of blood MCP-1 levels in adults with OSA compared to the controls (Asians: (p < 0.0001), mixed ethnicity: (p = 0.04), and Caucasians: (p = 0.89)). The meta-regression showed increasing serum/plasma MCP-1 levels in adults with OSA versus the controls, publication year, age of controls, body mass index (BMI) of controls, and sample size reduced, and also BMI and the apnea−hypopnea index of adults with OSA increased. Conclusions: The meta-analysis showed that compared to the controls, serum/plasma levels of MCP-1 in adults with OSA were significantly more, as well as adults with severe OSA having more serum/plasma MCP-1 levels compared to the adults with mild to moderate OSA. Therefore, MCP-1 can be used as a diagnostic and therapeutic factor in adults with OSA.

Assessing the causal associations of obstructive sleep apnea with serum uric acid levels and gout: a bidirectional two-sample Mendelian randomization study

OBJECTIVE

Multiple observational studies have reported the close associations of obstructive sleep apnea (OSA) with serum uric acid (SUA) levels and gout. However, the causal nature and direction remains unclear.

METHODS

A bidirectional two-sample Mendelian randomization (MR) study was performed, based on publicly available genome-wide association studies (GWAS) summary statistics, to investigate whether OSA is causally related to SUA levels, gout and vice versa. The inverse-variance weighted (IVW) was used as the primary analysis approach, supplemented with four sensitive analysis methods applied to assess the robustness of the results. Moreover, multivariable MR (MVMR) was utilized to evaluate the independent causal effect of OSA on SUA and gout after adjusting for body mass index (BMI), hypertension, type 2 diabetes (T2D), coronary artery disease (CAD), and chronic kidney disease (CKD).

RESULTS

Genetically predicted OSA liability was significantly associated with increased levels of SUA (IVW method: β = 0.19, 95% CI = 0.11 - 0.26, P = 7.24 × 10^-7) and risk of gout [IVW method: odds ratio (OR) = 1.75 95% CI = 1.13 - 2.69, P = 0.01] in univariable MR. The MVMR results suggested that OSA retained its significant association with increased SUA levels, whereas the significant association between OSA and gout was attenuated to null after adjusting for BMI and T2D. No causal effect of OSA on SUA levels and gout was found in the reverse direction.

CONCLUSIONS

Our findings suggest that OSA was causally associated with increased levels of SUA, but was not independently associated with gout risk.

A portrait of obstructive sleep apnea risk factors in 27,210 middle-aged and older adults in the Canadian Longitudinal Study on Aging

Determining the prevalence and characteristics of individuals susceptible to present with obstructive sleep apnea (OSA) is essential for developing targeted and efficient prevention and screening strategies. We included 27,210 participants aged ≥45 years old (50.3% women) from the Canadian Longitudinal Study on Aging. Using the STOP questionnaire combined to the percentage of body fat (%BF), we estimated the prevalence of individuals at high-risk for OSA in a sex and age-specific manner, and tested the relation with comorbidities, menopause and systemic inflammation. The prevalence was 17.5%, and was lower in women (13.1%) than in men (21.9%). A high level of high-sensitivity C-reactive protein was the strongest factor associated with OSA risk and this association was 1.3-2.3 times higher in women than in men. OSA risk increased with age, cardiovascular diseases, diabetes mellitus, anxio-depressive symptoms, asthma and arthritis. In women, post-menopausal status was associated with a high OSA risk. Nearly 1 adult out of 5 older than 45 is at risk for OSA in Canada. Comorbidities, menopause and systemic inflammation, more than age, explain increased OSA prevalence. Considering this high prevalence and associations with medical and mental comorbidities, health care practitioners should incorporate systematic OSA screening in their clinical procedures.

Development and Validation of a Nomogram for Predicting Obstructive Sleep Apnea in Patients with Pulmonary Arterial Hypertension

PURPOSE

Patients with pulmonary arterial hypertension (PAH) are at high risk for obstructive sleep apnea (OSA), which may adversely affect pulmonary hemodynamics and long-term prognosis. However, there is no clinical prediction model to evaluate the probability of OSA among patients with PAH. Our study aimed to develop and validate a nomogram for predicting OSA in the setting of PAH.

PATIENTS AND METHODS

From May 2020 to November 2021, we retrospectively analyzed the medical records of 258 patients diagnosed with PAH via right-heart catheterization. All participants underwent overnight cardiorespiratory polygraphy for OSA assessment. General clinical materials and biochemical measurements were collected and compared between PAH patients with or without OSA. Lasso regression was performed to screen potential predictors. Multivariable logistic regression analysis was conducted to establish the nomogram. Concordance index, calibration curve, and decision curve analysis were used to determine the discrimination, calibration, and clinical usefulness of the nomogram.

RESULTS

OSA was present in 26.7% of the PAH patients, and the prevalence did not differ significantly between male (29.7%) and female (24.3%) patients. Six variables were selected to construct the nomogram, including age, body mass index, hypertension, uric acid, glycated hemoglobin, and interleukin-6 levels. Based on receiver operating characteristic analysis, the nomogram demonstrated favorable discrimination accuracy with an area under the curve (AUC) of 0.760 for predicting OSA, exhibiting a better predictive value in contrast to ESS (AUC = 0.528) (P < 0.001). Decision curve analysis and clinical impact curve analysis also indicated the clinical utility of the nomogram.

CONCLUSION

By establishing a comprehensive and practical nomogram, we were able to predict the presence of OSA in patients with PAH, which may facilitate the early identification of patients that benefit from further diagnostic confirmation and intervention.

Study on Relationship Between Carotid Intima-Media Thickness and Inflammatory Factors in Obstructive Sleep Apnea

PURPOSE

The purpose of this study was to explore the change of carotid intima-media thickness (IMT) and its correlation with inflammatory markers in patients with different degrees of obstructive sleep apnea (OSA).

METHODS

One hundred hospitalized patients were selected and were divided into the normal control group (21 cases), the mild-moderate group (39 cases) and the severe group (40 cases) according to their apnea hypopnea index (AHI). Carotid IMT of all registered patients was studied with ultrasound, and serum levels of high-sensitivity C-reactive protein (hs-CRP), Lipoprotein-associated phospholipaseA2 (Lp-PLA2) and tumor necrosis factor-α (TNF-α) were measured. Pearson correlation analysis and multiple stepwise regression analysis were used to analyze the correlation between carotid IMT and inflammatory factors.

RESULTS

Patients with mild, moderate and severe OSA Carotid IMT had significantly higher levels of serum hs-CRP, Lp-PLA2 and TNF-α compared with the normal control group (P < 0.001). The levels of carotid IMT, serum protein hs-CRP, Lp-PLA2 and TNF-α in the severe OSA group were significantly higher than those of the mild-moderate OSA group, with P values being less than 0.001. Carotid artery IMT was positively correlated with serum hs-CRP (r = 0.83, P < 0.001), Lp-PLA2 (r =0.58, P < 0.001), and TNF-α (r =0.69, P < 0.001). hs-CRP, TNF-α and AHI were independent factors affecting carotid artery IMT. In addition, AHI was an independent indicator of carotid atherosclerosis (P = 0.0012).

CONCLUSION

Increased inflammatory factors in OSA patients might cause the progression of atherosclerosis, which might increase the risk of cardiovascular and cerebrovascular diseases in OSA patients.

Putative associations between inflammatory biomarkers, obesity, and obstructive sleep apnea

BACKGROUND:

Previous studies have reported increased levels of inflammatory mediators in patients with obstructive sleep apnea (OSA), but their relation with the severity of OSA is controversial.

OBJECTIVE:

To address potential relationships between OSA-related inflammatory markers, namely, C-reactive protein (CRP), interleukin-6 (IL-6), tumor necrosis factor-alpha (TNF-α), and fibrinogen, with different oxygenation parameters and with BMI.

METHODS:

All eligible patients with suspected OSA newly referred to the Sleep Medicine Research Center at King Abdulaziz University Hospital, Jeddah, were evaluated demographically and anthropometrically, and underwent overnight polysomnography. Fasting morning blood samples were collected to measure serum levels of CRP, fibrinogen, TNF-α, and IL-6. Potential correlations between these inflammatory mediators and severity measures of OSA and body mass index (BMI) were explored.

RESULTS:

Sixty-four patients completed the study (40 with OSA and 24 without OSA). Significantly increased levels of CRP, fibrinogen, IL-6, and TNF-α emerged in patients with OSA compared to non-OSA. Significant associations between log CRP and log fibrinogen levels emerged with increasing BMI. However, there was no significant association between any of the inflammatory markers and the severity of OSA based on the apnea/hypopnea index or oxyhemoglobin saturation-derived parameters.

CONCLUSIONS:

OSA patients exhibit increased levels of inflammatory mediators that do not appear to be associated with polysomnographic measures, but exhibit positive correlation with the degree of adiposity.

Alzheimer's Disease, Sleep Disordered Breathing, and Microglia: Puzzling out a Common Link

Sleep Disordered Breathing (SDB) and Alzheimer's Disease (AD) are strongly associated clinically, but it is unknown if they are mechanistically associated. Here, we review data covering both the cellular and molecular responses in SDB and AD with an emphasis on the overlapping neuroimmune responses in both diseases. We extensively discuss the use of animal models of both diseases and their relative utilities in modeling human disease. Data presented here from mice exposed to intermittent hypoxia indicate that microglia become more activated following exposure to hypoxia. This also supports the idea that intermittent hypoxia can activate the neuroimmune system in a manner like that seen in AD. Finally, we highlight similarities in the cellular and neuroimmune responses between SDB and AD and propose that these similarities may lead to a pathological synergy between SDB and AD.

Impact of Tonsillectomy on Obesity in Pediatric Patients With Sleep-Disordered Breathing

OBJECTIVE

Both tonsillar hypertrophy and obesity contribute to pediatric sleep-disordered breathing (SDB). Tonsillectomy addresses anatomical obstruction causing SDB; however, it may adversely affect the obesity profile postoperatively. Herein, we investigate posttonsillectomy body mass index (BMI) changes in pediatric patients.

STUDY DESIGN

Retrospective case series.

SETTING

Tertiary, pediatric urban academic center.

METHODS

All patients undergoing tonsillectomy from January 1, 2016, to December 31, 2016, were included. Patients' age, sex, surgical indication, and preoperative BMI were recorded. Postoperative BMI data were collected between March 1, 2016, and December 31, 2017. Statistical analysis was performed using a generalized regression model, using BMI percentile-for-age weight status.

RESULTS

A total of 1153 patients were included (50% female), with age ranging from 2.0 to 19.5 years (mean [SD], 7.6 [4.0]). The majority (87.8%) had tonsillectomy for SDB. Of the cohort, 560 (48.6%) had available follow-up BMI data. The BMI percentile on the day of the surgery had a median of 65.8, and the BMI percentile on follow-up had a median of 76.4. The median time to follow-up was 197 days with a range of 50 to 605 days. Higher postoperative BMI percentile strongly correlated to higher preoperative BMI percentile (P < .001), as well as younger age (P < .001), male sex (P = .0005), and SDB as a surgical indication (P = .003).

CONCLUSION

We observed a significant increase in BMI percentile following tonsillectomy, which accounted for a significantly higher proportion of the cohort being classified as overweight or obese postoperatively. These findings necessitate greater preoperative counseling, closer follow-up, and adjunctive measures for obesity management in pediatric patients undergoing tonsillectomy.

Obstructive Sleep Apnea, Hypercoagulability, and the Blood-Brain Barrier

Obstructive sleep apnea (OSA) is characterized by repeated episodes of intermittent hypoxia (IH) and is recognized as an independent risk factor for vascular diseases that are mediated by a multitude of mechanistic pathophysiological cascades including procoagulant factors. The pro-coagulant state contributes to the development of blood clots and to the increase in the permeability of the blood-brain barrier (BBB). Such alteration of BBB may alter brain function and increase the risk of neurodegenerative diseases. We aim to provide a narrative review of the relationship between the hypercoagulable state, observed in OSA and characterized by increased coagulation factor activity, as well as platelet activation, and the underlying neural dysfunction, as related to disruption of the BBB. We aim to provide a critical overview of the existing evidence about the effect of OSA on the coagulation balance (characterized by increased coagulation factor activity and platelet activation) as on the BBB. Then, we will present the emerging data on the effect of BBB disruption on the risk of underlying neural dysfunction. Finally, we will discuss the potential of OSA therapy on the coagulation balance and the improvement of BBB.

Obstructive Sleep Apnea and Cognitive Decline: A Review of Potential Vulnerability and Protective Factors

Around 40% of dementia risk is attributable to modifiable risk factors such as physical inactivity, hypertension, diabetes and obesity. Recently, sleep disorders, including obstructive sleep apnea (OSA), have also been considered among these factors. However, despite several epidemiological studies investigating the link between OSA and cognitive decline, there is still no consensus on whether OSA increases the risk of dementia or not. Part of the heterogeneity observed in previous studies might be related to some individual characteristics that modulate the association between OSA and cognitive decline. In this narrative review, we present these individual characteristics, namely, age, sex, menopause, obesity, diabetes mellitus, hypertension, cardiovascular diseases, smoking, excessive alcohol consumption, depression, air pollution, Apolipoprotein E ε4 allele, physical activity, and cognitive reserve. To date, large cohort studies of OSA and cognitive decline tended to statistically control for the effects of these variables, but whether they interact with OSA to predict cognitive decline remains to be elucidated. Being able to better predict who is at risk of cognitive decline when they have OSA would improve clinical management and treatment decisions, particularly when patients present relatively mild OSA.

Impact of inflammatory markers on the relationship between sleep quality and diabetic kidney disease

PURPOSE

Both poor sleep and diabetic kidney disease are closely associated with inflammation. However, the correlation between poor sleep and diabetic kidney disease has not been well clarified. Thus, the aim of this study was to determine the mediating role that inflammatory markers play in the pathogenic effect of poor sleep on the severity of diabetic kidney disease (DKD).

METHODS

A cross-sectional survey was conducted on 336 patients with type 2 diabetes (T2D). DKD was diagnosed according to the guidelines of the National Kidney Foundation-Kidney Disease Outcome Quality Initiative (NKF-K/DOQI). The Pittsburg Sleep Quality Index (PSQI) score was applied to assess patients for the quality of their sleep. Patients with a PSQI score of more than 5 were assigned to the poor sleep group, and the rest of the patients were assigned to the good sleep group. Circulating levels of six inflammatory biomarkers related to poor sleep and DKD were measured.

RESULTS

The prevalence of DKD was higher in patients with poor sleep quality than in those with good sleep quality (42% vs. 25%, P = 0.002). After adjustment, poor sleep quality (PSQI score OR 1.075 [95%CI 1.018-1.135], P = 0.009) remained independently associated with DKD. PSQI score was found to be positively related to fibroblast growth factor (FGF23), interleukin 6 (IL-6), P-selectin, and intercellular adhesion molecule-1 (ICAM-1) (P < 0.01), rather than fibrinogen and C-reactive protein (CRP) in linear regression models. As revealed by multiple mediation analysis, FGF23 and IL-6 mediated 26% and 23% of the relationship between PSQI score and urinary microalbumin (UMA), respectively. Similarly, the FGF23 and ICAM-1, instead of IL-6 and P-selectin, mediated 32% and 24% of the association between PSQI and estimated glomerular filtration rate (eGFR), respectively.

CONCLUSIONS

Poor sleep quality is independently associated with DKD. These results suggest that inflammatory markers contribute to a pathogenic connection between poor sleep and DKD.

Evaluation of Blood Levels of C-Reactive Protein Marker in Obstructive Sleep Apnea: A Systematic Review, Meta-Analysis and Meta-Regression

(1) Introduction: High sensitivity C-reactive protein (hs-CRP) and CRP are inflammatory biomarkers associated with several inflammatory diseases. In both pediatric and adult individuals with Obstructive Sleep Apnea (OSA) higher hs-CRP and CRP were observed, compared to controls. With the present systematic review, meta-analysis and meta-regression we expand upon previous meta-analyses in four ways: (1) We included 109 studies (96 in adults and 13 in children); (2) we reported subgroup and meta-regression analyses in adults with OSA compared to controls on the serum and plasma levels of hs-CRP; (3) we reported subgroup and meta-regression analyses in adults with OSA compared to controls on the serum and plasma levels of CRP; (4) we reported serum and plasma levels of both hs-CRP and CRP in children with OSA, always compared to controls. (2) Materials and Methods: The PubMed/Medline, Scopus, Cochrane Library, and Web of Science databases were searched to retrieve articles published until 31 May 2020, with no restrictions. The data included basic information involving the first author, publication year, country of study, ethnicity of participants in each study, age, BMI, and AHI of both groups, and mean and standard deviation (SD) of plasma and serum levels of CRP and hs-CRP. (3) Results: A total of 1046 records were retrieved from the databases, and 109 studies were selected for the analysis (96 studies reporting the blood levels of hs-CRP/CRP in adults and 13 studies in children). For adults, 11 studies reported plasma hs-CRP, 44 serum hs-CRP, 9 plasma CRP, and 32 serum CRP levels. For children, 6 studies reported plasma hs-CRP, 4 serum hs-CRP, 1 plasma CRP, and 2 serum CRP levels. Compared to controls, the pooled MD of plasma hs-CRP levels in adults with OSA was 0.11 mg/dL (p < 0.00001). Compared to controls, the pooled MD of serum hs-CRP levels in adults with OSA was 0.09 mg/dL (p < 0.00001). Compared to controls, the pooled MD of plasma CRP levels in adults with OSA was 0.06 mg/dL (p = 0.72). Compared to controls, the pooled MD of serum CRP levels in adults with OSA was 0.36 mg/dL (p < 0.00001). Compared to controls, the pooled MD of plasma hs-CRP, serum hs-CRP, plasma hs-CRP, and serum hs-CRP in children with OSA was 1.17 mg/dL (p = 0.005), 0.18 mg/dL (p = 0.05), 0.08 mg/dL (p = 0.10), and 0.04 mg/dL (p = 0.33), respectively. The meta-regression showed that with a greater apnea-hypapnea index (AHI), serum hs-CRP levels were significantly higher. (4) Conclusions: The results of the present systematic review, meta-analysis and meta-regression showed that compared to healthy controls plasma and serum levels of hs-CRP and serum CRP level were higher in adults with OSA; for children, and compared to controls, just plasma hs-CRP levels in children with OSA were higher.

Cognitive Outcomes after DEXmedetomidine sedation in cardiac surgery: CODEX randomised controlled trial protocol

INTRODUCTION

Older patients undergoing cardiac surgery carry the highest risk for developing major postoperative neurocognitive disorder (postoperative NCD or P-NCD) with up to 25% incidence 3 months after surgery. P-NCD is associated with significant morbidity, mortality, loss of independence, premature retirement and increased healthcare costs. This multicentre randomised trial is investigating the efficacy of postoperative dexmedetomidine sedation in reducing the incidence of major P-NCD after cardiac surgery compared with standard protocols. CODEX will be the largest interventional trial with major P-NCD as the primary outcome.

METHODS AND ANALYSIS

CODEX is recruiting patients ≥60 years old, undergoing elective cardiac surgery and without pre-existing major cognitive dysfunction or dementia. Eligible participants are randomised to receive postoperative dexmedetomidine or standard institutional sedation protocols in the intensive care unit. Baseline preoperative cognitive function is assessed with the computer-based Cogstate Brief Battery. The primary outcome, major P-NCD, 3 months after surgery is defined as a decrease in cognitive function ≥1.96 SD below age-matched, non-operative controls. Secondary outcomes include delirium, major P-NCD at 6/12 months, depressive symptoms, mild P-NCD and quality of surgical recovery at 3/6/12 months. The specific diagnostic criteria used in this protocol are consistent with the recommendations for clinical assessment and management of NCD from the Nomenclature Consensus Working Group on perioperative cognitive changes. Intention-to-treat analysis will compare major P-NCD at 3 months between study groups.

ETHICS AND DISSEMINATION

CODEX was approved by Sunnybrook Health Sciences Centre Research Ethics Board (REB) (Project ID 1743). This will be the first multicentre, randomised controlled trial to assess the efficacy of a pharmacological intervention to reduce the incidence of major P-NCD after cardiac surgery in patients ≥60 years old. Dissemination of the study results will include briefings of key findings and interpretation, conference presentations and peer-reviewed publications.

TRIAL REGISTRATION NUMBER

NCT04289142.

Obstructive Sleep Apnea Is Associated with Newly Diagnosed Gestational Diabetes Mellitus

Rationale: Sleep-disordered breathing (SDB) is associated with increased risk of adverse pregnancy outcomes, including gestational diabetes mellitus (GDM). GDM is a significant cause of maternal and infant morbidities. Assessing these risk factors concurrently may facilitate both the identification of women at GDM risk and the initiation of GDM prevention strategies.Objectives: To investigate whether SDB events, including SDB in rapid eye movement (REM) sleep and other sleep parameters, are associated with increased risk of GDM and to evaluate the performance of the models investigating associations between breathing and sleep parameters and GDM risk.Methods: In this case-control study, 46 women with newly diagnosed GDM and 46 healthy control subjects, who were individually matched for age, gestational age, body mass index, race, and parity, completed overnight polysomnographic studies and sleep questionnaires after being screened for GDM during the late-second to mid-third trimesters. Conditional logistic regression analysis was used to identify models investigating associations between risk factors and GDM risk. The Bayesian information criterion (BIC) was employed to compare models; the model with the lowest BIC is preferred.Results: Obstructive sleep apnea (OSA; defined as an apnea-hypopnea index [AHI] >5 events/h) was present in 22% of subjects with GDM and 9% of control subjects (P < 0.001). Women with OSA had a higher GDM risk (odds ratio [OR], 4.71; 95% confidence interval [CI], 1.05-21.04). In individual models, GDM risk was also significantly higher among women with higher overall AHI (events/h OR, 1.81; 95% CI, 1.01-3.27), higher AHI in REM (events/h OR, 2.09; 95% CI, 1.02-4.31), higher oxygen desaturation index greater than or equal to 4% (ODI4; events/h OR, 2.21; 95% CI, 1.03-4.73), and higher Sleep Apnea Symptom Score (OR, 2.72; 95% CI, 1.11-6.69). The percentage of non-REM sleep was significantly associated with decreased risk of GDM (percentage of non-REM sleep OR, 0.88; 95% CI, 0.78-0.99). The BIC supports the conclusion that there is a strong association between AHI in REM and GDM risk compared with the other significant models.Conclusions: SDB events, including REM-related OSA, are linked to increased GDM risk. GDM risk is also influenced by intercorrelated sleep variables.

Relation between oro-facial thermographic findings and myofunctional characteristics in patients with obstructive sleep apnoea

AIM

To evaluate the thermographic characteristics of oro-facial structures and submental triangle of participants with obstructive sleep apnoea (OSA), as well as to investigate its correlation with the anatomy, posture and functions of the oro-facial structures.

METHOD

Eighteen patients diagnosed with OSA by polysomnography (OSA group; 57.4 ± 15.8 years) and 13 healthy participants screened for OSA (control group; 57.8 ± 18.1 years) were included. All participants answered to questionnaires for OSA and excessive daytime sleepiness, and were submitted to infrared image thermography analysis of facial regions of interest (ROIs), oro-facial myofunctional evaluation (OMES-E protocol) and masticatory performance. Statistical analysis included one-way ANOVA and Pearson/Spearman correlation test.

RESULTS

Obstructive sleep apnoea group showed lower thermographic measures in many ROIs in the frontal and lateral views of the face, including the submental triangle region, and lower scores of aspect/posture and performance of oro-facial structures, as well lower total score of OMES-E evaluation (P < .05). Scores of aspect/posture and mobility were correlated with the temperature of some ROIs in the frontal and lateral views.

CONCLUSION

Lower facial skin and submental triangle region temperatures, measured by infrared thermography, and a worse oro-facial myofunctional condition were identified in the group of individuals with OSA. The higher temperatures of the ROIs were correlated with the better status of aspect/posture and performance of the oro-facial myofunctional structures.

Obstructive sleep apnea, intermittent hypoxemia and prothrombotic biomarkers

Objective

To study the serum levels of fibrinogen and d-dimer in patients with obstructive sleep apnea (OSA) and its correlation with apnea hypopnea index (AHI), oxygen desaturation index (ODI), minimal oxygen saturation and arousal index.

Methods

It was a case control study in which 23 cases of OSA and 23 controls were enrolled. Morning fasting serum fibrinogen and d-dimer were measured in cases of OSA and controls.

Results

Serum fibrinogen levels among OSA patients (268.47±53.11mg/dl) were elevated as compared to the levels in controls (221.52±65.84mg/dl) (p<0.05). Serum fibrinogen co-related positively with AHI (r=0.6381, p=0.0011) and ODI (r=0.7434, p=0.0000), negatively with minimal oxygen saturation (r=-0.4461, p=0.0329). There was no statistically significant correlation of fibrinogen with arousal index (r=0.2697, p=0.2133). There was no statistically significant difference between mean fasting d-dimer level in cases (0.12mg/L, 0.06±0.18mg/L) and controls (0.12mg/L, 0.02±0.22mg/L) (p=0.8926).

Conclusions

The observation of elevated fibrinogen levels with the increasing severity of OSA and hypoxemic events makes OSA one of the important risk factor for cardiovascular disorders.

Effects of continuous positive airway pressure on plasma fibrinogen levels in obstructive sleep apnea patients: a systemic review and meta-analysis

OBJECTIVE

Fibrinogen has been implicated to play a role in the pathophysiology of obstructive sleep apnea (OSA). Many studies have evaluated the effect of continuous positive airway pressure (CPAP) on plasma fibrinogen levels in OSA patients. However, results from different reports were not consistent. To assess the effect of CPAP treatment on plasma fibrinogen levels of patients with OSA, a meta-analysis was performed.

METHODS

A systematic search of Pubmed, Embase, Cochrane, Wanfang Database and Chinese National Knowledge Infrastructure was performed. Data were extracted, and then weighted mean difference (WMD) and 95% confidence intervals (CIs) were calculated using a random-effects model.

RESULTS

Twenty-two studies involving 859 patients were included in this meta-analysis. Combined data showed that plasma fibrinogen concentrations decreased after CPAP therapy (WMD = -0.38 g/l, 95% CI [-0.54 to -0.22 g/l], P<0.001). In the subgroup analyses by therapy duration, plasma fibrinogen concentrations declined significantly in the long-term (≥1 month) CPAP therapy subgroup (WMD = -0.33 g/l, 95% CI [-0.49 to -0.16 g/l], P<0.001) but not in the short-term (<1 month) CPAP therapy subgroup (WMD = -0.84 g/l, 95% CI [-1.70 to 0.03 g/l], P=0.058). Moreover, in patients with long-term CPAP therapy duration, plasma fibrinogen levels decreased with good CPAP compliance (≥4 h/night) (WMD = -0.37 g/l, 95% CI [-0.55 to -0.19 g/l], P<0.001) but not with poor CPAP compliance (<4 h/night) (WMD = 0.12 g/l, 95% CI [-0.09 to 0.33 g/l], P=0.247).

CONCLUSION

Long-term CPAP treatment with good compliance can reduce the plasma fibrinogen levels in patients with OSA.

The relationship between inflammation and neurocognitive dysfunction in obstructive sleep apnea syndrome

Obstructive sleep apnea syndrome (OSAS), a state of sleep disorder, is characterized by repetitive apnea, chronic hypoxia, oxygen desaturation, and hypercapnia. Previous studies have revealed that intermittent hypoxia (IH) conditions in OSAS patients elicited neuron injury (especially in the hippocampus and cortex), leading to cognitive dysfunction, a significant and extraordinary complication of OSAS patients. The repeated courses of airway collapse and obstruction in OSAS patients resulted in apnea and arousal during sleep, leading to IH and excessive daytime sleepiness (EDS) and subsequently contributing to the development of inflammation. IH-mediated inflammation could further trigger various types of cognitive dysfunction. Many researchers have found that, besides continuous positive airway pressure (CPAP) treatment and surgery, anti-inflammatory substances might alleviate IH-induced neurocognitive dysfunction. Clarifying the role of inflammation in IH-mediated cognitive impairment is crucial for potentially valuable therapies and future research in the related domain. The objective of this article was to critically review the relationship between inflammation and cognitive deficits in OSAS.

Precision multiparameter tracking of inflammation on timescales of hours to years using serial dried blood spots

Aim: High-frequency longitudinal tracking of inflammation using dried blood microsamples provides a new window for personalized monitoring of infections, chronic inflammatory disease and clinical trials of anti-inflammatory drugs. Results/methodology: Using 1662 dried blood spot samples collected by 16 subjects over periods of weeks to years, we studied the behavior of 12 acute phase response and related proteins in inflammation events correlated with infection, vaccination, surgery, intense exercise and Crohn's disease. Proteins were measured using SISCAPA mass spectrometry and normalized to constant plasma volume using low-variance proteins, generating high precision within-person biomarker trajectories with well-characterized personal baselines. Discussion/conclusion: The results shed new light on the dynamic regulation of APR responses, offering a new approach to visualization of multidimensional inflammation trajectories.

Associations of Inflammation, Physical Activity, and Sleep in a Diverse Population of Women

Background: Cardiovascular disease (CVD) is the leading cause of mortality in United States with a recent rise seen in young adults, particularly women. Systemic inflammation, physical activity, and sleep are each individually linked to CVD risk. Whether there is an interaction of these variables, however, is unclear. We evaluated physical activity and sleep among racially ethnically diverse women, ages 20-79 years, to assess associations with systemic inflammation. Methods: We performed a cross-sectional study of 506 women (61% racial/ethnic minority; mean (standard deviation [SD]) age = 37 [15.7] years, body mass index 26.0 [5.7] kg/m²) enrolled in the American Heart Association (AHA) Go Red for Women Strategically Focused Research Network at Columbia University Irving Medical Center (CUIMC). Inflammation, assessed by C-reactive protein (CRP), was analyzed in the Biomarkers Core Laboratory at CUIMC. Physical activity and sleep were assessed using validated questionnaires. Multivariable models adjusted for demographic and clinical confounders were used to evaluate associations between CRP, physical activity, and sleep. Results: Mean (SD) physical activity was 282 (557.2) minutes/week, and mean (SD) sleep duration was 6.75 (1.24) hours/night. Mean CRP was 2.08 (3.56), and 17% of participants were categorized as high risk for obstructive sleep apnea (OSA). Participants who slept <6 hours/night were less likely to be physically active ≥150 minutes/week (odds ratios, ORs [95% confidence interval, CI]: 0.53 [0.33-0.84]). This association was nonsignificant after adjustment. High risk of OSA was associated with CRP ≥2 mg/L (OR [95% CI]: 1.91 [1.11-3.30]) following adjustment. Stratification by race/ethnicity showed that high risk of OSA was associated with CRP ≥2 mg/L among racial/ethnic minorities but not white women (OR [95% CI]: 2.75 [1.43-5.30] vs. 0.94 [0.31-2.88]). Conclusion: High risk of OSA and elevated CRP was significantly associated in women, particularly minority women. Both play a role in CVD, highlighting potential causes for the increased risk of CVD in younger women.

Predictors of chronic kidney disease in obstructive sleep apnea patients

Introduction

Obstructive sleep apnea (OSA) is a common condition in patients with chronic kidney disease (CKD). It may worsen renal function in CKD patients and is associated with uncontrolled blood pressure. Although OSA is found in up to 80% of CKD patients, there are limited data available on its clinical features in patients with and without CKD.

Objective

This study aimed to identifying the differences in the clinical characteristics of OSA between CKD and non-CKD OSA patients and determine the clinical predictors for CKD in OSA patients.

Methods

This was a retrospective study conducted at Khon Kaen University's Srinagarind Hospital in Thailand between July and December 2018. The inclusion criteria were diagnosis with OSA via polysomnography and having undergone laboratory tests for CKD. Obstructive sleep apnea is diagnosed according to the apnea-hypopnea index (AHI) as experiencing ≥5 events/hour, while CKD diagnosed based on the KDOQI guidelines. Eligible patients were divided into two groups: OSA with CKD and OSA without CKD. Predictors of CKD in OSA patients were analyzed using multivariate logistic regression analysis.

Results

During the study period, there were 178 OSA patients who met the study criteria, 88 (49.44%) of whom were in the OSA with CKD group. Both age and body mass index were comparable between OSA patients with CKD and those without (age: 59 and 57 years, respectively; body mass index: 30 and 29 kg/m², respectively. There were three significant factors that differed between those with and without CKD group including systolic blood pressure (147 vs 135 mmHg), proportion of patients with diabetes (55% vs 34%), and proportion of patients with Mallampati scores of 3-4 (73% vs 39%). There were three independent predictors for OSA in patients with CKD: female sex, high systolic blood pressure, and Mallampati score of 3 or 4, with adjusted odds ratios (95% confidence interval) of 4.624 (1.554, 13.750), 1.060 (1.020, 1.101), and 2.816 (1.356, 5.849), respectively. The Hosmer-Lemeshow chi-square statistic of the predictive model was 6.06 (p 0.640). Systolic blood pressure of more than 130 and 150 mmHg resulted in sensitivity of 84.21% and specificity of 81.40%, respectively.

Conclusions

Female sex, high systolic blood pressure, and Mallampati score of 3-4 were suggestive of OSA with CKD. Obstructive sleep apnea patients with one or more of these predictors may have a high risk of CKD.

Periodontal disease, sleep duration, and white blood cell markers in the 2009 to 2014 National Health and Nutrition Examination Surveys

BACKGROUND

Elevated levels of inflammatory biomarkers are consistently associated with chronic conditions, for which periodontitis and sleep are established risk factors. We examined the relationships between periodontitis, hours of sleep and white blood cell (WBC) markers among a nationally representative sample of US adults.

METHODS

Cross-sectional study using existing demographic, examination, laboratory and questionnaire data on 11,813 participants (5,814 men and 5,999 women, mean age ± SE; range: 52.74 ± 0.24; 30 to 80 years) from the 2009 to 2014 National Health and Nutrition Examination Surveys. Unadjusted, sex- and age-adjusted, as well as fully adjusted linear and logistic regression models were conducted in addition to generalized structural equations models, while considering sampling design complexity. β, odds ratios with their 95% confidence intervals, indirect effects and mediation proportions were estimated.

RESULTS

The weighted mean WBC count was 7,130 cells/µL, with the WBC 5-part differential estimated in terms of percentages of lymphocytes (29.50%), monocytes (7.99%), neutrophils (59.03%), eosinophils (2.84%), and basophils (71.88%). Furthermore, 36.2% of participants reported <7 hours of sleep and 49.8% had periodontitis. In fully adjusted models controlling for sociodemographic, lifestyle, and health characteristics, neither WBC markers nor periodontitis were related to hours of sleep. By contrast, periodontitis was directly related to WBC count and %neutrophils and inversely related to %lymphocytes, especially among men. However, the relationship of periodontitis with %neutrophils and %lymphocytes may be modified by hours of sleep, as it was specific to individuals reporting ≥7 hours of sleep.

CONCLUSION

Periodontitis may be directly related to WBC count and %neutrophils and inversely related to %lymphocytes, especially among men and individuals reporting ≥7 hours of sleep, with implications for primary and secondary prevention.

Plasma urate concentrations and possible REM sleep behavior disorder

Objective

To examine how urate concentrations are related to the risk of having possible REM sleep behavior disorder (pRBD) in a community‐based cohort.

Methods

The study included 12,923 Chinese adults of the Kailuan Study, free of Parkinson disease (PD) and dementia. Plasma urate concentrations were measured in 2006, 2008, and 2010. Cumulative average urate concentration was used as primary exposure. In 2012, we determined pRBD status using a validated RBD questionnaire‐Hong Kong (RBDQ‐HK). Logistic regression analysis was performed to estimate the association between urate concentrations during 2006–2010 and odds of having pRBD in 2012 or pRBD case with symptom onset within 1 year.

Results

Higher average urate concentrations were associated with a lower odds of pRBD (P‐trend <0.001). The adjusted odds ratio (OR), for the highest versus lowest urate quintiles, was 0.43 (95% confidence intervals (CIs) 0.32–0.57). Significant association was consistently observed when we examined the association of a single urate assessment (2006 or 2010) or the rate of change in urate concentrations during 2006–2010 with pRBD (P‐trend <0.001 for all). However, restricting to pRBD onset during 2011–2012, we observed a nonsignificant trend between high urate concentration and high odds of pRBD (P‐trend = 0.09).

Interpretation

Higher average urate concentrations were associated with a lower likelihood of having pRBD, but not new‐onset pRBD. Because of its observational study design, the result should be interpreted with caution due to the possibility of residual confounding.

Circulating fibrinogen levels are elevated in patients with obstructive sleep apnea: a systemic review and meta-analysis

OBJECTIVE

Fibrinogen is believed to play a role in the pathophysiology of obstructive sleep apnea (OSA) and many studies have assessed circulating fibrinogen concentrations in OSA patients. However, the results from these studies were not consistent. To assess the association of circulating fibrinogen levels and OSA, a meta-analysis was performed.

METHODS

PubMed, Embase and Web of Science databases were searched for eligible studies. Data were extracted, and then weighted mean differences (WMDs) with 95% confidence intervals (CIs) were calculated.

RESULTS

A total of 25 studies involving 1480 cases and 2312 controls were included in this meta-analysis. Combined data indicated that the circulating fibrinogen levels were higher in OSA patients than in controls (WMD: 0.38 g/L, 95% CI [0.29-0.47 g/L], p < 0.001; I² = 80.3%, p < 0.001). In the subgroup analyses by disease severity, there were similar results in mild-moderate OSA patients (WMD: 0.27 g/L, 95% CI [0.14-0.41 g/L], p < 0.001; I² = 29.3%, p = 0.185) and severe OSA patients (WMD: 0.54 g/L, 95% CI [0.28-0.79 g/L], p < 0.001; I² = 65.9%, p = 0.012). Furthermore, in another subgroup analysis, the circulating fibrinogen levels were higher in OSA patients than those in controls who were matched for important potential confounders (WMD: 0.41 g/L, 95% CI [0.21-0.60 g/L], p < 0.001; I² = 62.0%, p = 0.003).

CONCLUSIONS

This systematic review and meta-analysis reveals that circulating fibrinogen levels are elevated in patients with OSA.

Relationship between monocyte to HDL cholesterol ratio and concomitant cardiovascular disease in Chinese Han patients with obstructive sleep apnea

Background

Obstructive sleep apnea (OSA) is an independent risk factor for cardiovascular disease (CVD), which is attributed to chronic intermittent hypoxia (CIH) induced inflammation. As a new inflammatory biomarker of CVD, monocyte to high-density lipoprotein cholesterol ratio (MHR) has received little attention in OSA studies to date. Therefore, we aimed to investigate the correlation between MHR and concomitant CVD in Chinese Han patients with OSA.

Methods

A total of 657 Chinese Han subjects (169 controls, 145 mild, 94 moderate, and 249 severe OSA) of both genders were enrolled in this cross-sectional study, with an average BMI of 32.35±6.56 kg/m². The relationship between MHR and concomitant CVD in OSA patients was analyzed.

Results

The level of MHR was correlated positively with apnea-hypopnea index (AHI), while negatively with lowest SpO₂ (P<0.01). Moreover, the MHR values were higher in OSA patients with CVD than those without CVD (17.64±7.16 vs. 12.73±5.06, P<0.001). Logistic regression analysis demonstrated that MHR is an independent predictor of CVD (OR =1.190, P<0.001). The ROC analysis indicated that the best cut-off value of MHR for predicting CVD in OSA patients was 15.364 (sensitivity 65.0%, specificity 74.4%), while its cutoff value for identifying CVD in severe OSA patients was 15.362 (sensitivity 67.3%, specificity 80.1%).

Conclusions

MHR is strongly correlated with the severity of OSA and the occurrence of CVD in OSA patients. As an easy and available test, MHR is expected to be a promising biomarker candidate in predicting CVD in Chinese Han patients with OSA.

Serum Uric Acid Is Independently Associated with Risk of Obstructive Sleep Apnea-Hypopnea Syndrome in Chinese Patients with Type 2 Diabetes

Purpose

We aimed to investigate the association between serum uric acid (SUA) levels and obstructive sleep apnea-hypopnea syndrome (OSAHS) in patients with type 2 diabetes.

Methods

A cross-sectional study of 212 type 2 diabetes mellitus (T2DM) patients was conducted in Xiamen, China. All patients underwent polysomnography (PSG) recordings for OSAHS diagnosis. Patients were grouped according to the apnea-hypopnea index (AHI) as mild (5-14.9), moderate (15-29.9), and severe (≧30) OSAHS. Patients with AHI ≤ 4.9 served as the control group. Weight, body mass index (BMI), SUA, liver function, renal function, blood pressure, lipid profiles, and glycemic parameters were measured.

Results

A total of 158 patients (101 men and 57 women) with complete data were analyzed in this study. 127 patients were identified as OSAHS. Among the 127 patients with OSAHS, 56 (44.1%), 37 (29.1%), and 34 (26.8%) had mild, moderate, and severe OSAHS, respectively. Correlation analyses showed that the SUA level was significantly related to the apnea-hypopnea index (AHI) (r = 0.194, p = 0.016). The level of SUA was significantly higher among OSAHS patients compared to the control group (control group: 333.14 ± 80.52 μmol/L, mild group: 345.50 ± 90.27 μmol/L, moderate group: 363.59 ± 134.26 μmol/L, and severe group: 428.37 ± 123.58 μmol/L and p = 0.029). Multivariable logistic regression analyses showed that SUA was the independent risk factor for OSAHS (OR: 1.006, 95% CI: 1.001-1.011, p = 0.020).

Conclusions

The SUA level is significantly associated with the severity of OSAHS and should be controlled when managing OSAHS.

Obstructive sleep apnoea and venous thromboembolism: pathophysiological links and clinical implications

Obstructive sleep apnoea (OSA) and pulmonary embolism (PE) remain major health issues worldwide. Data from pathophysiological studies suggest that both intermittent hypoxia and sleep fragmentation are associated with increased blood coagulability, endothelial dysfunction and venous stasis. There is growing evidence that OSA is potentially prevalent in and a risk factor for PE. Conversely, patients with acute PE have two to four times greater risk of moderate-to-severe OSA. The role of continuous positive airway pressure (CPAP) treatment in improving clinically meaningful outcomes in PE patients remains unclear, although some authors have suggested that CPAP could improve the hypercoagulability state and normalise circadian alterations in some of the coagulation molecules, as observed in patients with OSA. Emerging research highlights the complex interdependent relationships between OSA and PE, emphasising the need for rigorous, well-powered trials that address the impact of OSA and its treatment on the prevention and management of PE. Undoubtedly, these will require closer collaboration between the sleep medicine and clinical/venous thromboembolism communities.

Obstructive Sleep Apnea and Inflammation: Proof of Concept Based on Two Illustrative Cytokines

Obstructive sleep apnea syndrome (OSAS) is a markedly prevalent condition across the lifespan, particularly in overweight and obese individuals, which has been associated with an independent risk for neurocognitive, behavioral, and mood problems as well as cardiovascular and metabolic morbidities, ultimately fostering increases in overall mortality rates. In adult patients, excessive daytime sleepiness (EDS) is the most frequent symptom leading to clinical referral for evaluation and treatment, but classic EDS features are less likely to be reported in children, particularly among those with normal body-mass index. The cumulative evidence collected over the last two decades supports a conceptual framework, whereby sleep-disordered breathing in general and more particularly OSAS should be viewed as low-grade chronic inflammatory diseases. Accordingly, it is assumed that a proportion of the morbid phenotypic signature in OSAS is causally explained by underlying inflammatory processes inducing end-organ dysfunction. Here, the published links between OSAS and systemic inflammation will be critically reviewed, with special focus on the pro-inflammatory cytokines tumor necrosis factor α (TNF-α) and interleukin 6 (IL-6), since these constitute classical prototypes of the large spectrum of inflammatory molecules that have been explored in OSAS patients.

Androgens modulate chronic intermittent hypoxia effects on brain and behavior

Sleep apnea is associated with testosterone dysregulation as well as increased risk of developing neurodegenerative diseases, such as Alzheimer's disease (AD) and Parkinson's disease (PD). A rodent model of the hypoxemic events of sleep apnea, chronic intermittent hypoxia (CIH), has been previously documented to impair cognitive function and elevate oxidative stress in male rats, while simultaneously decreasing testosterone. Therefore, androgens may modulate neuronal function under CIH. To investigate the role of androgens during CIH, male rats were assigned to one of four hormone groups: 1) gonadally intact, 2) gonadectomized (GDX), 3) GDX + testosterone (T) supplemented, or 4) GDX + dihydrotestosterone (DHT) supplemented. Each group was exposed to either normal room air or CIH exposure for one week, followed by memory and motor task assessments. Brain regions associated with AD and PD (entorhinal cortex, dorsal hippocampus, and substantia nigra) were examined for oxidative stress and inflammatory markers, key characteristics of AD and PD. Gonadally intact rats exhibited elevated oxidative stress due to CIH, but no significant memory and motor impairments. GDX increased memory impairments, regardless of CIH exposure. T preserved memory function and prevented detrimental CIH-induced changes. In contrast, DHT was not protective, as evidenced by exacerbated oxidative stress under CIH. Further, CIH induced significant spatial memory impairment in rats administered DHT. These results indicate androgens can have both neuroprotective and detrimental effects under CIH, which may have clinical relevance for men with untreated sleep apnea.

Sex differences in sleep apnea and comorbid neurodegenerative diseases

Sleep apnea is a disorder, which increasingly affects people worldwide. Whether the associated hypoxic events during sleep are central or obstructive in origin, the end result is excessive daytime sleepiness and an increased risk for several comorbidities, such as cardiovascular and neurodegenerative disorders. Sleep apnea is diagnosed more frequently in men than women, suggesting a role of sex hormones in the pathology of the disease. Furthermore, there are sex differences in the development and progression of comorbid diseases associated with sleep apnea. Therefore, treatment of sleep apnea may be clinically relevant for prevention of subsequent sex-specific comorbid disorders. While the impact sleep apnea has on cardiovascular events has been the subject of many research studies, the role of sleep apnea in neurodegeneration is less established. Here we review known risk factors for sleep apnea and the implications of the observed sex differences in this disease. We also summarize the evidence and mechanisms for how sleep apnea may contribute to the onset of neurodegenerative disorders, such as Alzheimer's disease and Parkinson's disease.

Intermittent hypoxia, cardiovascular disease and obstructive sleep apnoea

Obstructive sleep apnoea (OSA) is a common disorder and is associated with cardiovascular disease. Continuous positive airway pressure (CPAP), whilst reducing blood pressure, has not been shown to reduce cardiovascular events when used as a treatment solely for this purpose in patients with previous cardiovascular disease. Developing a better understanding of the mechanisms underlying cardiovascular disease in OSA is important to develop new treatments. Potential causative mechanisms for cardiovascular disease in OSA include arousal induced sympathetic activation, large intrathoracic pressure swings leading to shear stress on the heart and great vessels, and intermittent hypoxia (IH). This review discusses the role of IH, as a major physiological consequence of OSA, in the development of cardiovascular disease.