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Objective: This study aimed to investigate the impact of surgical intervention on peripheral blood T lymphocyte subsets and natural killer (NK) cell activity in pediatric patients with obstructive sleep apnea hypopnea syndrome (OSAHS)., Methods: A total of 36 OSAHS children, 32 children with tonsillar hypertrophy, and 30 healthy children were enrolled. Clinical data and polysomnography (PSG) results were collected. Peripheral blood samples were analyzed for T lymphocyte subsets, NK cells, and cytokine levels including Th1 (IFN-γ, IL-2, TNF-α), Th2 (IL-4, IL-10), and Th17 (IL-17)., Results: At baseline, OSAHS children exhibited lower LSaO2 levels and higher AHI values compared to healthy children. They also showed decreased percentages of CD3 + T cells, CD4 + T cells, NK cells, and elevated CD8 + T cells and CD4+/CD8 + ratio. Levels of IFN-γ, IL-2, TNF-α, IL-4, and IL-17 were significantly lower in OSAHS children. Post-surgery improvements were observed in LSaO2, AHI, and immune markers at 3 months and 6 months. Pearson's correlation analysis revealed significant associations between LSaO2, AHI, and peripheral blood immune parameters at baseline and 6 months post-surgery., Conclusion: Surgical intervention in pediatric OSAHS influences peripheral blood T lymphocyte subsets and NK cell activity. Early intervention and monitoring of immune function are crucial for the recovery and healthy development of affected children., (© 2024. The Author(s), under exclusive licence to Springer Nature Switzerland AG.)

Purpose: Obstructive sleep apnoea hypoventilation syndrome (OSAHS) is a common sleep disorder that affects multiple body systems, which in turn is closely associated with cognitive dysfunction, diabetes mellitus, oncological cardiovascular diseases and metabolic disorders. In recent years, non-coding RNA (ncRNA) has emerged as a new opportunity for biomarker discovery. We therefore discuss the research progress and potential role of ncRNAs in obstructive sleep apnea hypoventilation syndrome., Methods: This review systematically searched relevant academic literature from PubMed, Web of Science and other databases. During the retrieval process, a combination of keywords such as "OSAHS", "ncRNA", "lncRNA", "miRAN", "circRNA" was used for search., Results: Circulating ncRNA has good area under the ROC curve, sensitivity and specificity in the diagnosis of OSAHS, and has the potential to become a diagnostic marker for OSAHS, while several circulating ncRNAs or circulating ncRNAs in combination with other tests such as the Obstructive Sleep Apnoea Screening Scale have a higher value of application as a test for OSAHS. Further analyses revealed that many circulating ncRNAs were significantly differentially expressed in the serum of OSAHS patients with different very severities, a potential marker for predicting the severity of OSAHS, and that the ncRNA content of patients' serum also had a significant effect during CPAP therapy, suggesting that it may have potential for therapeutic monitoring. Meanwhile, serum ncRNAs from patients have been shown to be effective in the diagnosis of OSAHS complications such as hypertension, Alzheimer's disease, acute myocardial infarction and atherosclerosis. The expression of up- or down-regulated ncRNAs can regulate different signalling pathways, which in turn affects various OSAHS complications such as pulmonary hypertension, diabetes mellitus, and cognitive dysfunction, and is expected to become a new direction for the treatment of these complications., Conclusions: The changes in ncRNA expression in OSAHS patients are expected to be a novel biomarker for the diagnosis and treatment of OSAHS, and can also be used as a potential biomarker for the combination of diabetes mellitus, cardiovascular disease, respiratory disease, and cognitive dysfunction in OSAHS. It is believed that the continuous progress of ncRNA-related research is expected to promote the early detection, diagnosis and treatment of OSAHS and its complications., (© 2024. The Author(s), under exclusive licence to Springer Nature Switzerland AG.)

Purpose: Hypoxia and sleep fragmentations that develop during sleep cause central nervous system damage in patients with obstructive sleep apnea (OSA). This study investigates the relationship between OSA severity and glial fibrillary acidic protein (GFAP) and c-Fos, which are considered indicators of neuronal damage., Methods: The study included 84 participants (70 patients with OSA and 14 healthy individuals). All participants were evaluated with the Epworth Sleepiness Scale (ESS) before polysomnography (PSG), and serum GFAP and c-Fos values were measured after PSG. All participants were grouped according to the apnea-hypopnea index (AHI) score (control: AHI < 5, Mild OSA: 5 ≤ AHI < 15; moderate OSA: 15 ≤ AHI < 30; severe OSA: AHI ≥ 30)., Results: The average age of the participants was 48.5 ± 11.4 years. According to AHI scoring, 14 healthy individuals (16.7%) were in the control group, and 70 patients (83.3%) were in OSA groups. The serum GFAP levels and c-Fos levels were increased in the OSA groups (7.1 ± 5.7 ng/mL and 7.9 ± 7.5 pg/mL respectively) compared to the control group (1.3 ± 0.4 ng/mL and 2.7 ± 1.4 pg/mL p < 0.001 and p < 0.01, respectively). There was a significant positive correlation between AHI and oxygen desaturation index (ODI) values, which indicate disease severity, and serum c-Fos (r: 0.381 and r:0.931, p < 0.01, respectively) and GFAP (r: 0.793 and r:0.745, p < 0.01, respectively) values., Conclusion: Serum GFAP and c-Fos values, which are considered indicators of neuronal damage, can be used as a serum marker to determine disease severity in OSA., (© 2024. The Author(s), under exclusive licence to Springer Nature Switzerland AG.)

Purpose: Endocan is a biomarker of endothelial dysfunction, which is a precursor to cardiovascular disease. Obstructive sleep apnoea (OSA) is associated with elevated endocan levels but the effects of treatment on endocan levels in OSA are not fully established. We aimed to determine whether endocan levels could be detected by immunoassay and to determine the effect of supplemental oxygen during continuous positive airway pressure (CPAP) withdrawal on circulating endocan levels., Methods: We conducted an exploratory analysis from a randomised controlled crossover study which included participants with OSA. Participants stopped their CPAP therapy and were randomised to receive either supplemental oxygen or sham for 14 nights before crossing over. Supplemental oxygen blocked the rise in blood pressure seen in the sham group. We analysed plasma endocan levels by immunoassay at baseline and after 14 nights of intervention in both groups., Results: Twenty-five participants were included, with a total of 100 samples. Endocan levels were detectable at all time points in 22 participants (88%), and in 93 (93%) samples. Supplemental oxygen had no effect on endocan levels compared to sham (+ 0.52 ng/ml, 95%CI -0.21 to + 1.25, p = 0.16), and there was no significant difference in endocan levels from baseline to follow-up in either the sham (-0.30 ng/ml, 95%CI -0.89 to + 0.30, p = 0.31) or supplemental oxygen (+ 0.22 ng/ml, 95%CI 0.00 to + 0.44, p = 0.05) arm., Conclusions: We have shown that endocan levels are detectable before and after CPAP withdrawal. However, we found no effect of supplemental oxygen following CPAP withdrawal on circulating endocan levels., Trial Registration and Date: ISRCTN 17,987,510 19/02/2015., Competing Interests: Declarations Ethical approval All procedures performed in studies involving human participants were in accordance with the ethical standards of the South Central Oxford B Research Ethics Committee (REC Reference 15/SC/0007) and with the 1964 Helsinki declaration and its later amendments or comparable ethical standards. Compliance with ethical standards Funding: This study was funded by the Oxford Radcliffe Hospital Charitable Funds and ResMed UK. Conflict of interest Dr. Chris Turnbull declares honoraria from Stowood, outside the scope of this work. Dr. Nayia Petousi, Prof John Stradling, and Dr Philippe Lassalle declare no conflict of interest. Informed consent Informed consent was obtained from all individual participants included in the study., (© 2024. The Author(s).)

Objective: Triglyceride-glucose index (TyG) and its derived indices which better reflect metabolic disturbances on atherosclerosis has not been reliably compared in patients with type 2 diabetes mellitus (T2DM). Besides, obstructive sleep apnea hypopnea syndrome (OSAHS), a driver of atherosclerosis (AS), can exacerbate metabolic disturbances strongly. The aim of this study is to explore the mediating effect of glycolipid metabolism on the association between OSAHS and arterial stiffness in T2DM patients., Methods: 154 T2DM patients were involved in this study and were split into two groups: T2DM and T2DM + AS. Logistic regression analysis determined the accurate effects of different factors on the AS of T2DM patients. The capacity of TyG and the indices it derives to predict AS was assessed using the receiver operating characteristic (ROC) curve. Mediation analysis was employed to investigate the mediating effect of TyG and its derived indices on the association between OSAHS and arterial stiffness in T2DM patients., Results: OSAHS, TyG, and its derived indices were independent risk factors for AS in T2DM patients. Stratified by age, the hazardous effects of TyG and its derived indices remained significant in T2DM patients aged ≥ 50 years, but not in those aged < 50 years. In T2DM patients aged ≥ 50 years, the novel indices have a high predictive value for AS, with TyG-BMI exhibiting the largest AUC(AUC:0.788;95% CI:0.647 ∼ 0.928; P < 0.001). The mediation analysis results indicated that in T2DM patients aged ≥ 50 years, TyG, TyG-BMI, TyG-WC, and TyG-WHtR acted as potential mediators in the association between OSAHS and AS, with mediation effects of 33.42%, 48.2%, 37.7%, and 40.21%, respectively. However, there was no significant mediating effect observed in the younger patients., Conclusion: TyG and its derived indices are strongly correlated with AS in T2DM patients, of which TyG-BMI has the best predictive performance. Besides, OSAHS partially exerts its atherogenic effect through glucolipid metabolism disorder in the T2DM population aged ≥ 50 years, while it mainly exerts a direct atherogenic effect in patients aged < 50 years., Competing Interests: Declarations Ethical approval This study was approved by the Ethics Committee of the First People’s Hospital of Changzhou. Consent to participate All participants were consent to participate with the informed consent. Consent for publication All authors approve the publication. Conflict of interest All authors certify that they have no affiliations with or involvement in any organization or entity with any financial interest in this manuscript., (© 2024. The Author(s), under exclusive licence to Springer Nature Switzerland AG.)

Introduction: Intermittent hypoxemia has an important role in the physiopathogenesis of obstructive sleep apnea (OSA) complications. Increased apoptosis due to intermittent hypoxemia may be an important clinical entity in OSA. In this study, we aimed to evaluate caspase-3 enzyme level, which is an indirect marker of increased apoptosis in patients with OSA and to evaluate the effect of OSA treatment with continuous positive airway pressure on caspase-3 enzyme level., Materials and Methods: This study included 141 consecutive patients admitted to the sleep-disordered breathing laboratory within 6 months. Caspase-3 was measured in routine blood samples obtained on the morning of polysomnography (PSG) performed at night. The compliance of the patients to CPAP treatment was evaluated and caspase-3 levels were checked again after treatment., Results: A total of 141 patients, 39 females (27,7%) and 102 males (72,3%) were included in the study. The mean age of the patients was 49 ± 12 years (min-17, max-77). According to PSG results, OSA was detected in 95.7% (135/141) of the cases. Mild OSA was 35 (24.8%), moderate OSA 39 (27.7%) and severe OSA 61 (43.3%) cases. Median caspase-3 enzyme levels were similar in men and women in the study group. There was no statistically significant difference in hemogram parameters and caspase-3 enzyme levels between the groups divided according to the presence and severity of OSA. It was determined that caspase-3 enzyme level did not change significantly after 3 months of CPAP treatment in OSA compared to pretreatment. Caspase-3 was found to have a negative correlation with both the percentage of daily use of CPAP therapy and the percentage of CPAP device use for more than 1 h per night. It was found that the control caspase-3 level decreased statistically significantly as the percentage of daily use of CPAP therapy increased (r = -0.397, p = 0.030). It was found that the control caspase-3 level decreased statistically significantly as the percentage of CPAP therapy use for more than 1 h per night increased (r = -0.411, p = 0.024)., Conclusion: The results of this study did not reveal a relationship between the severity of OSA and caspase-3 levels. However, blood caspase-3 levels decreased as treatment compliance increased, suggesting that CPAP treatment may correct increased apoptosis in OSA. There is a need for more comprehensive studies on this issue., (© 2024. The Author(s), under exclusive licence to Springer Nature Switzerland AG.)

Background: Obstructive sleep apnea-hypopnea syndrome (OSAHS) is a common respiratory disease with potential lethality. At present, the commonly used treatment method is continuous positive airway pressure ventilation, but with the prolongation of the course of the disease, the effect of single ventilation on the improvement of oxidative stress levels is not good. Lipoic acid is a commonly used antioxidant in clinics. In this paper, lipoic acid combined with continuous positive airway pressure ventilation is used to explore whether it has a better therapeutic effect on patients., Aim: To probe into the clinical efficacy of lipoic acid combined with continuous positive airway pressure ventilation in the therapy of OSAHS., Methods: 82 patients with OSAHS who were cured in our hospital from March 2021 to September 2022 were prospectively collected as subjects. Based on different treatment methods, patients were grouped into a control group (43 cases) and an observation group (39 cases). The control group was treated with continuous positive airway pressure (CPAP), and the observation group was treated with lipoic acid based on control group. The therapeutic effects were measured by apnea hypopnea index (AHI), oxygen saturation (SpO2), mean oxygen saturation (MSpO2), serum malondialdehyde (MDA), superoxide dismutase (SOD), hypoxia inducible factor-1α (HIF-1α) levels, peripheral blood γ-aminobutyric acid, melatonin levels., Results: The clinical effectiveness of the observation group was better (P < 0.05). After treatment, AHI, the levels of MDA and HIF-1α in the observation group were lower and SpO 2 , MSpO 2 and the level of SOD, γ- aminobutyric acid, and melatonin were higher than those in the control group (P < 0.05). The levels of γ- aminobutyric acid and melatonin were negatively correlated with the severity of symptoms, ESS, and AIS scores (P < 0.05)., Conclusions: The clinical effect of lipoic acid combined with CPAP in the treatment of OSAHS is better, and it has a positive effect on the levels of γ-aminobutyric acid and melatonin in peripheral blood. Lipoic acid was added to the original method for treatment, and the therapeutic effect was greatly improved., (© 2024. The Author(s), under exclusive licence to Springer Nature Switzerland AG.)

We performed a matched-pair analysis of the content of GDF11 and GDF15 proteins in the plasma of patients (56 middle-aged men) with obstructive sleep apnea syndrome (OSAS) and healthy volunteers (27 men with no complaints of sleep disorders). The groups were comparable in terms of age and presence of chronic diseases. No statistically significant differences in GDF11 content in the studied groups were revealed, while the content of GDF15 in the OSAS group was 1.3 times higher. These results require further research from the viewpoint of geriatric somnology and molecular biology., (© 2024. Springer Science+Business Media, LLC, part of Springer Nature.)

Purpose: This study aimed to explore the association between anti-mullerian hormone (AMH) levels and obstructive sleep apnea (OSA) severity., Methods: A cross-sectional design was employed to evaluate AMH levels in 68 premenopausal women diagnosed with OSA at Van Yüzüncü Yıl University Faculty of Medicine. OSA severity was scored according to the 2018 AASM guidelines using a 16-channel Embla device. AMH levels were measured from blood samples using a commercially available kit., Results: The study found that AMH levels in OSA patients were significantly lower than those in the healthy control group. A statistically significant negative correlation between AMH and AHI levels was observed. When stratified by OSA severity, the lowest AMH levels were found in the severe OSA group., Conclusion: OSA may have potential endocrine implications, especially concerning reproductive health. Decreased AMH levels in OSA patients could indicate future risks of infertility or early menopause., (© 2024. The Author(s), under exclusive licence to Springer Nature Switzerland AG.)

Purpose: The aim of this study is to investigate the role of the neutrophil to lymphocyte ratio (NLR) in patients diagnosed with the chronic obstructive pulmonary disease-obstructive sleep apnea (COPD-OSA) overlap syndrome and comorbid pulmonary hypertension (PH)., Patients and Methods: We enrolled a consecutive of stable COPD patients and conducted spirometry measurements, nocturnal polysomnography (PSG), and echocardiography for all participants. Clinical laboratory data were collected., Results: A total of 178 patients with stable COPD were enrolled among whom 33.14% (59/178) were diagnosed with OSA. Of the patients with overlap syndrome, 35.59% (21/59) showed comorbid PH, compared to 34.45% (41/119) in COPD patients without OSA. There was no significant difference in the occurrence of PH between COPD with and without OSA. NLR was significantly higher in patients with overlap syndrome compared to those with either disease alone. The difference in NLR between COPD-OSA patients with and without PH was not significant. Correlation analysis revealed that NLR was associated with age, total sleep time spent with oxygen saturation below 90% (T90), CRP, pulmonary artery systolic pressure (PASP), and minimum peripheral capillary oxygen saturation (SpO2min) in all COPD patients. NLR was identified as an independent factor contributing to OSA in COPD. The median cut-off value for detecting OSA in stable COPD was 2.49. However, NLR was not found to be a predictor for PH in COPD-OSA overlap syndrome., Conclusions: NLR can serve as a predictive marker for comorbid OSA in patients with COPD. NLR is expected to increase its clinical application as a convenient and cost-effective biomarker for COPD-OSA overlap syndrome., (© 2024. The Author(s), under exclusive licence to Springer Nature Switzerland AG.)

Background: Obstructive sleep apnea (OSA) can be considered a chronic inflammatory disease that impacts all bodily systems, including the immune system. This study aims to assess the Th17/Treg pattern in patients with OSA and the effect of continuous positive airway pressure (CPAP) treatment., Methods: OSA patients and healthy controls were recruited. OSA patients recommended for CPAP treatment were followed up for three months. Flow cytometry was employed to determine the proportion of Th17 and Treg cells. Real-time quantitative polymerase chain reaction (PCR) and western blotting were utilized to detect the mRNA and protein levels of receptor-related orphan receptor γt (RORγt) and forkhead/winged helix transcription factor (Foxp3), respectively, in peripheral blood mononuclear cells (PBMCs). Enzyme-linked immunosorbent assay (ELISA) was performed to measure the serum levels of interleukin-17 (IL-17), IL-6, transforming growth factor-β1 (TGF-β1), and hypoxia-induced factor-1α (HIF-1α)., Results: A total of 56 OSA patients and 40 healthy controls were recruited. The proportion of Th17 cells, Th17/Treg ratio, mRNA and protein levels of RORγt, and serum IL-17, IL-6, and HIF-1α levels were higher in OSA patients. Conversely, the proportion of Treg cells, mRNA and protein levels of Foxp3, and serum TGF-β1 levels were decreased in OSA patients. The proportion of Th17 and Treg cells in OSA can be predicted by the apnea hypopnea index (AHI), IL-6, TGF-β1 and, HIF-1α. 30 moderate-to-severe OSA patients were adherent to three-month CPAP treatment, with improved Th17/Treg imbalance, IL-17, IL-6, TGF-β1, and HIF-1α levels compared to pre-treatment values., Conclusion: There was a Th17/Treg imbalance in OSA patients. The prediction of Th17 and Treg cell proportions in OSA can be facilitated by AHI, as well as serum IL-6, TGF-β1, and HIF-1α levels. Furthermore, CPAP treatment can potentially improve the Th17/Treg imbalance and reduce proinflammatory cytokines in OSA patients., (© 2024. The Author(s), under exclusive licence to Springer Nature Switzerland AG.)

Purpose: To evaluate the effects of nocturnal asthma on sleep parameters and inflammatory markers according to the severity of the condition in participants in the São Paulo Epidemiologic Sleep Study (EPISONO)., Methods: Data from the 2007 and 2018 editions of the EPISONO study were utilized. Subjects completed validated sleep and respiratory questionnaires, underwent nocturnal polysomnography and spirometry tests, and provided blood samples for the assessment of inflammatory parameters., Results: Of 72 participants (67% women), 53% (n = 38) had intermittent nocturnal asthma symptoms and 47% (n = 34) had persistent asthma (mild, moderate, and severe). Individuals with persistent nocturnal symptoms had a higher body mass index (BMI), were more likely to have respiratory symptoms, and had worse lung function, a higher apnea-hypopnea index (AHI), and higher desaturation index than individuals with intermittent nocturnal symptoms. Positive associations were identified between nocturnal asthma and obstructive sleep apnea (OSA). A higher frequency of OSA was observed in participants with persistent asthma and participants with OSA were more likely to have persistent than intermittent asthma. However, there were no significant differences between the immunological parameters of those with intermittent or persistent asthma., Conclusions: This study highlights the relevance of nocturnal symptoms as a valuable indicator of asthma severity. The findings also add to the existing body of evidence linking nocturnal asthma and OSA., (© 2023. The Author(s), under exclusive licence to Springer Nature Switzerland AG.)

Background: Previous studies have revealed that sleep structure and hypoxemia are two important environmental factors for cognitive impairment in patients with obstructive sleep apnea-hypopnea syndrome (OSAHS). We hypothesized that the pathophysiological mechanisms between these two factors may also be involved in cognitive impairment in patients with OSAHS. Previous studies have suggested that alterations in serum glucose and lipid metabolism, inflammatory responses, and astrocyte markers not only contribute to sleep structural disorders in OSAHS but also affect the occurrence and development of this disease. Therefore, we hypothesized that alterations in the abovementioned indicators may be involved in cognitive impairment in OSAHS. Additionally, obesity is an important risk factor for OSAHS. This study therefore aimed to explore the correlation between serum indicators and cognitive impairment in patients with OSAHS., Methods: Patients with OSAHS who underwent polysomnography in our hospital were recruited in this study. The overall cognitive function of patients were evaluated using the Mini mental State Examination (MMSE). Blood biochemical indicators such as glucose (GLU), triglycerides (TG), and triglyceride glucose (TyG) index were measured. Enzyme-linked immunosorbent assay (ELISA) was used to determine the levels of serum glucagon-like peptide-1 receptor (GLP-1R), fibroblast growth factor 21 (FGF21), S100 calcium binding protein B (S100B), brain derived neurotrophic factor (BDNF), inflammatory factors such as C-reactive protein (CRP), tumor necrosis factor-α (TNFα), interleukin-4 (IL-4), interleukin-1β (IL-1β), and interleukin-6 (IL-6). Spearman correlation analysis was used to determine if the indicator was related to cognitive function, and backward linear regression analysis was used to identify the main risk factors for cognitive impairment in non-obese and obese patients with OSAHS., Results: Among 34 patients, 19 were non-obese and 15 were obese. Obese patients exhibited higher AHI compared to non-obese individuals, and the difference was statistically significant (p < 0.05). In non-obese patients, Spearman correlation analysis revealed a negative correlation between serum GLU, IL-4, and MMSE scores (p < 0.05); IL-6 was positively correlated with MMSE (p < 0.05). In addition, GLU and IL-6 were independently correlated with MMSE in non-obese patients (p < 0.05). In obese patients, serum TG and TyG were positively correlated with MMSE scores (p < 0.05); age, BMI, and IL-4 were negatively correlated with MMSE scores (p < 0.05). In addition, age and IL-4 were independently correlated with MMSE in obese patients (p < 0.05)., Conclusions: Our data suggested that GLU and IL-6 were independently correlated with cognitive impairment in non-obese patients with OSAHS; age and IL-4 were independently correlated with cognitive impairment in obese patients. Early detection of this difference in heterogeneity may provide theoretical support for future investigations in prevention and treatment of cognitive impairment in patients with OSAHS., (© 2023. The Author(s), under exclusive licence to Springer Nature Switzerland AG.)

Purpose: Vitamin D deficiency has been associated with the occurrence of obstructive sleep apnea syndrome (OSAS). Megalin (LRP2) and cubilin (CUBN) are implicated in vitamin D metabolism, whereas LRP2 and CUBN polymorphisms have been previously associated with variable serum vitamin D levels. The present study aimed to evaluate the role of LRP2 rs2228171 c.8614C > T and CUBN rs1801222 c.758A > G polymorphisms in OSAS susceptibility, independently or in synergy with vitamin D levels., Methods: Vitamin D serum concentration of consecutive individuals was measured. PCR-RFLP was used for LRP2 rs2228171 and CUBN rs1801222 genotyping., Results: A total of 176 individuals was enrolled, including 144 patients with OSAS and 32 controls. Frequency of LRP2 rs2228171 c.8614 T and CUBN rs1801222 c.758G alleles was estimated at 22.4% and 79.8%, respectively. LRP2 and CUBN polymorphisms were not associated with OSAS occurrence (rs2228171Τ allele: 22.9% in OSAS group vs. 20.3% in controls, p = 0.651; rs1801222A allele 19.4% in OSAS group vs. 23.4% in controls, p = 0.471). Frequency of CUBN rs1801222A allele carriers was increased in patients with moderate or severe OSAS compared to mild OSAS (p = 0.028). Patients with OSAS homozygous for LRP2 CC and CUBN GG genotypes had lower vitamin D serum concentration compared to controls carrying the same genotype (18.0 vs 27.0 ng/mL, p = 0.006 and 19.0 vs 27.5 ng/mL, p = 0.007, respectively)., Conclusion: CUBN rs1801222 polymorphism may affect OSAS severity. Among other factors, low vitamin D concentration is associated with OSAS occurrence, irrespectively of LRP2 and CUBN polymorphisms., (© 2023. The Author(s).)

Purpose: This study aimed to investigate the predictive value of circulating irisin levels in discriminating the presence and severity of obstructive sleep apnea (OSA) in obese individuals., Methods: This study was conducted on obese volunteers with and without OSA. All volunteers underwent polysomnography. Blood samples were taken on the day of the test. In addition to routine biochemistry studies, irisin levels were determined by enzyme-linked immunosorbent measurement. ROC analysis was performed to determine the predictive value of irisin., Results: Of 100 volunteers, 75 had OSA and 25 did not. Irisin levels were significantly lower in the group with OSA than in the non-OSA group. The lowest irisin levels were determined in the group with severe OSA. Irisin levels showed high sensitivity and specificity in distinguishing between OSA and non-OSA groups. It had high sensitivity and specificity in differentiating severe OSA from other groups in subgroups, while it had low sensitivity and specificity in differentiating patients with mild and moderate OSA. In logistic regression analysis, a low irisin level was determined to be a risk factor for OSA independent of BMI., Conclusion: This study indicated that irisin levels decrease in obese individuals with OSA, correlating with the severity of the condition. Additionally, irisin levels may act as an independent predictor for OSA. The predictive value of irisin in identifying severe OSA among obese patients suggests its potential as a promising biomarker., (© 2023. The Author(s), under exclusive licence to Springer Nature Switzerland AG.)

Purpose: This review aimed to evaluate the effects of oral appliance (OA) therapy on serum inflammatory cytokines in adults diagnosed with obstructive sleep apnea (OSA)., Methods: Seven electronic databases and partial gray literature were searched without restrictions through March 2021. Articles evaluating the levels of serum inflammatory cytokines in patients with OSA after OA treatment were included. The risk of bias (RoB) was assessed using the before-and-after tool or RoB 2.0. The level of certainty was assessed using the GRADE tool., Results: Five studies met the eligibility criteria. One was a randomized clinical trial (RCT), while four were non-randomized clinical trials (NRCTs). Among the studies, C-reactive protein (CRP), IL-6, IL-10, IL-1β, and tumor necrosis factor α (TNF-α) were investigated. The RCT reported no significant differences in marker levels after 2 months of OA therapy, while the NRCTs showed improvement on CRP, TNF-α, and IL-1β levels after longer follow-up periods. The RoB was evaluated as showing some concern in the RCT. Three NRCTs presented good RoB, and one showed a fair RoB. The level of certainty was graded as moderate quality for inflammatory marker levels assessed in the RCT The levels of certainty evaluated in NRCTs were classified as very low., Conclusions: Although limited, existing scientific evidence showed that OA therapy may improve serum cytokine levels in adults with OSA. However, short treatment periods are not effective in reducing markers of systemic inflammation which may require extended time and a decrease of in apneic events to improve., (© 2021. The Author(s), under exclusive licence to Springer Nature Switzerland AG.)

Purpose: Obstructive sleep apnea syndrome (OSAS) is an independent risk factor for cardiovascular diseases. The aim of the study was to assess the influence of OSAS on endothelial dysfunction and thrombosis biomarkers and to evaluate the effect of treatment with continuous positive airway pressure (CPAP) on biomarker levels., Methods: NT-proBNP, sICAM-1, endothelin-1, von Willebrand factor, D-dimers, and thrombin-antithrombin complex (TAT) were measured in 50 patients diagnosed with moderate-to-severe OSAS. All patients underwent transthoracic echocardiography, and 38 months after the inclusion, 16 CPAP users and 22 non-CPAP users were reassessed., Results: Sleep-related indices of apnea-hypopnea index (AHI) and mean SpO 2 were associated with higher sICAM-1 levels (AHI < 30: 7.3 ± 4.7 vs. AHI ≥ 30: 19.5 ± 19.4 mg/ml, p = 0.04; SpO 2  ≥ 90%: 11.9 ± 9.3 vs. SpO 2  < 90%: 23.6 ± 25.8, p = 0.04). sICAM-1 levels were significantly higher in obese patients, particularly with BMI ≥ 40. Plasma levels of TAT were significantly correlated with the increased right ventricular size (right ventricular diameter ≤ 37 mm: 0.86 ± 0.70 vs. > 37 mm: 1.96 ± 1.20 ng/ml, p = 0.04). Endothelin-1 levels were higher in patients with decreased right ventricular function (right ventricle TDI-derived S' ≥ 12 cm/s: 11.5 ± 10.9 vs. < 12 cm/s: 26.0 ± 13.2 pg/ml, p = 0.04). An increase in NT-proBNP was related to impaired parameters of the right ventricular contractile function. There were no correlations between long-term CPAP therapy and the levels of biomarkers., Conclusion: Severe OSAS influences endothelial damage as manifested by an increase in sICAM-1 levels. Changes in right ventricular structure and function, observed mainly in patients with higher TAT and endothelin-1 levels, are also manifested by an increase in NT-proBNP levels. Long-term CPAP treatment does not seem to influence biomarkers in patients with moderate-to-severe OSAS, which may help to explain the lack of influence of CPAP on cardiovascular risk reduction., (© 2021. The Author(s).)

Purpose: Obstructive sleep apnea (OSA) is a prevalent sleep disorder associated with increased risk of cardiovascular disease. Several studies have demonstrated elevated oxidative stress in patients with OSA. This oxidative stress is a direct inducer of lipid peroxidation. Malondialdehyde (MDA), a robust marker of lipid peroxidation, has been evaluated in patients with OSA but results have been inconsistent. The present systematic review and meta-analysis was performed to quantify the circulating levels of MDA in patients with OSA compared to controls., Methods: Search was performed in data bases of PubMed, Scopus, EMBASE, Web of Science, and Cochrane library, to find out those studies that measured MDA in patients with OSA compared to controls., Results: The search produced 563 records and after removing duplicates, 383 records remained. Screening by title and abstract and the evaluation of the full text resulted in the selection of 14 articles, which were included in the meta-analysis. Pooled analysis demonstrated higher levels of MDA in the patients compared to the controls (SMD (95% CI): 1.18 (0.68, 1.68), p < 0.0001)., Conclusion: The results of this meta-analysis demonstrated considerable elevation of MDA in patients with OSA compared to controls. The meta-analysis also indicated a positive association of MDA levels with the degree of severity of OSA. These results suggest a state of increased lipid peroxidation in patients with OSA., (© 2021. The Author(s), under exclusive licence to Springer Nature Switzerland AG part of Springer Nature.)

Purpose: Obstructive sleep apnea (OSA) may contribute to metabolic and inflammatory deregulation but previous studies failed to consider sleep duration, sleep fragmentation, insomnia, and daytime sleepiness as potential confounders., Methods: Consecutive non-diabetic middle-aged participants from the ELSA-Brasil cohort were invited to perform a clinical evaluation, home sleep study for 1 night, and wrist actigraphy for 7 days. OSA was defined by an apnea-hypopnea index ≥ 15 events/h. Participants were stratified according to the presence of OSA measuring the following markers: fasting glucose, glucose tolerance test, homeostatic model assessment of insulin resistance (HOMA-IR) index, fasting insulin, insulin after 2 h of glucose load, glycated hemoglobin, total cholesterol and their fractions, triglycerides, C-reactive protein, TNF-alpha, interleukin-6, interleukin-10, leptin, adiponectin, E-selectin, ADMA, MCP-1, TGF, apolipoprotein B, fibrinogen, and lipoprotein(a). Differences between groups were identified by chi-square test and ANOVA., Results: We studied 708 participants (mean age: 46 ± 5 years, men: 44%, BMI 26.1 ± 4.1 kg/m 2 ). Compared to no OSA, participants with OSA presented higher levels while fasting and after 2 h glucose load of insulin, HOMA-IR, cholesterol, triglycerides, and C-reactive protein (all p < 0.001). After linear regression analysis adjusting for traditional risk factors plus sleep duration, fragmentation, insomnia, and daytime sleepiness, OSA was negatively associated with adiponectin (β = - 0.271 CI 95% - 0.456 - 0.085) and positively associated with cholesterol (β = 9.707 CI 95% 2.737 16.678). Sex-stratification revealed that these associations were significant for men but not women., Conclusions: In non-diabetic middle-age adults, men with OSA presented with lower adiponectin and higher cholesterol levels independently of sleep duration, sleep fragmentation, insomnia, and daytime sleepiness., (© 2021. The Author(s), under exclusive licence to Springer Nature Switzerland AG part of Springer Nature.)

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/m 2 ) 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/m 2 vs 39.4 kg/m 2 ), 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., (© 2021. The Author(s).)

Objective: Asprosin, a recently discovered adipokine, stimulates the release of hepatic glucose. The purpose of the current research was to determine the relation between serum asprosin and obstructive sleep apnea syndrome (OSAS)., Methods: The current investigation enrolled 152 patients with OSAS and 97 control subjects. Serum asprosin concentrations were measured and analyzed., Results: Higher serum asprosin concentrations were found in patients with OSAS than in the controls. Logistic regression analysis demonstrated that serum asprosin concentrations were associated with an increased risk of OSAS. Patients with severe OSAS had significantly increased asprosin compared to mild and moderate groups. The group with moderate OSAS showed higher serum asprosin levels than the group with mild OSAS. Pearson correlation analysis demonstrated a positive relation between serum asprosin and disease severity. Simple linear regression analyses showed a significant correlation between serum asprosin with body mass index (BMI), fasting plasma glucose (FPG), homeostasis model assessment of insulin resistance (HOMA-IR), triglycerides (TG), and apnea-hypopnea index (AHI), and negatively correlated with high-density lipoprotein cholesterol (HDL-C). Multiple linear regression analysis revealed a significant correlation between serum asprosin with BMI, FPG, HOMA-IR, TG, AHI, and HDL-C., Conclusion: There is a significant correlation between serum asprosin with the presence and severity of OSAS., (© 2021. The Author(s), under exclusive licence to Springer Nature Switzerland AG part of Springer Nature.)

Serum serotonin levels were determined by HPLC in 30 patients with diagnosed obstructive sleep apnea syndrome before and after 3-month course of PAP-therapy and in 14 subjects without obstructive sleep apnea symptoms. It was found that elimination of hypoxic conditions was associated with an increase in serotonin level. The results demonstrate the effectiveness of PAP-therapy during sleep and allow assessing the role of serotonin as a potential biomarker of intermittent hypoxia during sleep., (© 2021. Springer Science+Business Media, LLC, part of Springer Nature.)

Purpose: Obstructive sleep apnea (OSA) has been related to vascular inflammation and production of endothelial cell adhesion molecules (CAMs). We aimed to determine night-morning variation of CAMs in patients with OSA compared to controls and the effect of one-night continuous positive airway pressure (CPAP) treatment on them., Methods: Nonsmoking men went through a full-attended polysomnography (PSG) study. Participants with moderate to severe OSA went through another PSG study while being treated with CPAP. Participants who did not have OSA composed the control group. Serum levels of intercellular adhesion molecule-1 (ICAM-1), vascular adhesion molecule-1 (VCAM-1), and E-selectin were measured before and after sleep on both nights., Results: Of 30 men, 20 had moderate to severe OSA while 10 did not. Night and morning ICAM-1 levels of patients with OSA were significantly higher than controls (p = 0.002 and p < 0.0001 respectively), while both night and morning VCAM-1 and E-selectin levels were not. Morning ICAM-1 levels of controls were significantly lower than night levels (p = 0.031), while morning ICAM-1, VCAM-1, and E-selectin levels of patients with OSA and morning VCAM-1 and E-selectin levels of controls were not. After CPAP treatment, the morning ICAM-1 levels, but not VCAM-1 levels, of patients with OSA were significantly lower than night levels (p = 0.006) and E-selectin levels showed a tendency for reduction (p = 0.06)., Conclusions: OSA is associated with elevated night and morning ICAM-1 levels in adult men with OSA. Even one night of CPAP treatment restores the normal night-morning variation of ICAM-1 levels and may have an effect on E-selectin levels, as well., (© 2020. Springer Nature Switzerland AG.)

Purpose: Obstructive sleep apnea (OSA) results in systemic intermittent hypoxia. By one model, hypoxic stress signaling in OSA patients alters the levels of inflammatory soluble cytokines TNF and IL6, damages the blood brain barrier, and activates microglial targeting of neuronal cell death to increase the risk of neurodegenerative disorders and other diseases. However, it is not yet clear if OSA significantly alters the levels of the soluble isoforms of TNF receptors TNFR1 and TNFR2 and IL6 receptor (IL6R) and co-receptor gp130, which have the potential to modulate TNF and IL6 signaling., Methods: Picogram per milliliter levels of the soluble isoforms of these four cytokine receptors were estimated in OSA patients, in OSA patients receiving airways therapy, and in healthy control subjects. Triplicate samples were examined using Bio-Plex fluorescent bead microfluidic technology. The statistical significance of cytokine data was estimated using the nonparametric Wilcoxon rank-sum test. The clustering of these high-dimensional data was visualized using t-distributed stochastic neighbor embedding (t-SNE)., Results: OSA patients had significant twofold to sevenfold reductions in the soluble serum isoforms of all four cytokine receptors, gp130, IL6R, TNFR1, and TNFR2, as compared with control individuals (p = 1.8 × 10 -13 to 4 × 10 -8 ). Relative to untreated OSA patients, airways therapy of OSA patients had significantly higher levels of gp130 (p = 2.8 × 10 -13 ), IL6R (p = 1.1 × 10 -9 ), TNFR1 (p = 2.5 × 10 -10 ), and TNFR2 (p = 5.7 × 10 -9 ), levels indistinguishable from controls (p = 0.29 to 0.95). The data for most airway-treated patients clustered with healthy controls, but the data for a few airway-treated patients clustered with apneic patients., Conclusions: Patients with OSA have aberrantly low levels of four soluble cytokine receptors associated with neurodegenerative disease, gp130, IL6R, TNFR1, and TNFR2. Most OSA patients receiving airways therapy have receptor levels indistinguishable from healthy controls, suggesting a chronic intermittent hypoxia may be one of the factors contributing to low receptor levels in untreated OSA patients., (© 2020. The Author(s).)

Purpose: The kynurenine (Kyn) pathway may play a role in certain physiological functions such as behavior, sleep, thermoregulation, and pregnancy. Tryptophan (Trp) is oxidized with tryptophan 2,3-dioxygenase and indolamine 2,3-dioxygenase (IDO). Under normal conditions, hepatic kynurenine is a transcription factor and IDO expression in healthy tissues is very low. The ratio of Kyn to Trp can be used as an indicator to assess IDO activity. This study aimed to determine the relationship between Kyn/Trp ratio and obstructive sleep apnea syndrome (OSAS) disease activity., Methods: Study participants were categorized in 3 groups: Group 1 included patients with mild OSAS, Group 2, patients with moderate to severe OSAS, and Group 3, individuals considered normal to serve as controls. The demographic characteristics of the patients were recorded. Apnea-hypopnea index (AHI) and oxygen desaturation index (ODI) measurements were performed by diagnostic polysomnography (PSG). Trp and Kyn levels were determined by HPLC-UV method., Results: Group 1 included 30 patients (18 men) with mild OSAS; Group 2 included 42 patients (31 men) with moderate to severe OSAS; and Group 3 included 25 controls (13 men). While there was no statistically significant difference between the levels of tryptophan and kynurenine in the groups, a significant difference was found between the Kyn/Trp ratios. A significant correlation was observed in individuals with a body mass index less than 25 with the Kyn/Trp ratio. In individuals with mild OSAS, a significant correlation was observed between ODI and BMI. In individuals with moderate to severe OSAS, there was a significant correlation between ODI, AHI, and BMI., Conclusion: In this study, there was no relationship between OSAS disease severity and IDO activity as assessed by immunoreactivity via the Kyn/Trp pathway., (© 2020. Springer Nature Switzerland AG.)

Purpose: The monocyte to high-density lipoprotein ratio (MHR) has been postulated to be a novel indicator associated with adverse cardiovascular outcomes in patients with coronary artery disease (CAD). These patients often have obstructive sleep apnea (OSA) and whether or not MHR may provide prognostic value for this comorbidity remains unclear. Therefore, we sought to explore the clinical value of MHR in evaluating OSA in patients with CAD., Methods: Consecutive patients with CAD were prospectively recruited and were assigned into four groups based on the quartiles of MHR. Portable monitoring for detecting nocturnal respiratory events was utilized to provide the diagnosis of OSA. Patients were defined as having OSA when respiratory event index ≥ 15 events/h. Univariate and multivariate regression analyses were used to explore the independent association between the levels of MHR and OSA., Results: A total of 1243 patients with CAD was included with a prevalence of OSA reaching 40% (n = 497). Patients with higher levels of MHR experienced increasing severity of OSA. In univariate analysis, MHR was a risk factor for OSA (odds ratio [OR] 1.90, 95% confidence interval [CI] 1.33-2.71, p < 0.001). Multivariate analysis showed that MHR was independently associated with the presence of OSA (OR 1.63, 95% CI 1.06-2.52, p = 0.027) after adjusting for possible confounding factors., Conclusions: Elevated levels of MHR were independently associated with a higher likelihood of OSA in patients with CAD. MHR could be a screening tool and a risk biomarker of OSA in such patients., (© 2021. Springer Nature Switzerland AG.)

Background: Renalase plays an important role in blood pressure regulation. Obstructive sleep apnea (OSA) is a common respiratory disorder associated with hypertension and cardiovascular complications. The aim of the study was to assess the relationship between sleep apnea and renalase concentration., Material and Methods: Adult patients (n = 113) were evaluated for OSA in a sleep laboratory using polysomnography. The respiratory events were scored according to the standards developed by the American Academy of Sleep Medicine. The blood renalase concentration was determined by the ELISA (enzyme-linked immunosorbent assay) test., Results: OSA (AHI ≥ 5) was diagnosed in 71% (n = 80) of the studied population. Renalase concentration was statistically significantly lower in the group with moderate-to-severe OSA (AHI ≥ 15) compared with the group without OSA (AHI < 5) (139.56 ± 175.72 ng/ml vs. 230.97 ± 240.50 ng/ml, p = 0.042). We have found statistically significant negative correlation between renalase and AHI in hypertensives, but not in normotensives. The statistically significant negative correlation was observed between AHI and renalase in the whole studied group, in males, and in the group of age < 60 years old. There was not such a correlation in females and in the group > 60 years old. Based on the regression model, it was shown that lower renalase concentration, hypertension, higher BMI, and male gender are independently associated with higher AHI., Conclusions: There is a relationship between the blood renalase concentration and the severity of OSA, which may influence hypertension development in OSA.

Background: Obstructive sleep apnea (OSA) is often associated with multisystem damage. The gut is a pivotal organ that initiates the pathophysiological processes of multisystem diseases. Intermittent hypoxia resulting from OSA may impair the intestinal barrier prior to the induction of systemic inflammation. We hypothesize that the intestinal barrier markers D-lactic acid (D-LA) and intestinal fatty acid-binding protein (I-FABP) levels would be higher in patients with OSA., Methods: Consecutive snoring and nonsnoring adults were included in this study and were grouped based on their apnea-hypopnea index (AHI) scores: the control group (AHI < 5) and the OSA group (AHI ≥ 5). Plasma D-LA and I-FABP levels were measured using colorimetry and ELISA, respectively. Other parameters, such as fasting levels of lipids, routine blood tests, and glucose were also assessed., Results: Of 76 participants, patients in the OSA group accounted for 73% (55/76). Plasma D-LA and I-FABP levels were significantly higher in patients with OSA [7.90 (7.42) (IQR) vs. 0.88 (2.79) (IQR) mmol/L, p < 0.001 and 1851.99 ± 754.23 (SD) vs. 1131.98 ± 383.38 pg/mL, p < 0.001, respectively]. Increased glucose, triglycerides (TGs), leukocytes, neutrophils, and monocytes but decreased high density lipoprotein (HDL) were also found in patients with OSA. It was also observed that the increase in D-LA and I-FABP exhibited the strongest positive association with AHI (r = 0.443, p < 0.001; r = 0.645, p < 0.001), followed by the lowest SaO2 (p ≤ 0.001), BMI (p ≤ 0.017), glucose (p ≤ 0.011), and TGs (p ≤ 0.025). Moreover, multivariate regression analysis showed that D-LA (B = 0.823, p < 0.001) and I-FABP (B = 0.002, p = 0.017) were independently associated with OSA., Conclusions: The systemic expression of D-LA and I-FABP is dramatically higher in OSA patients, suggesting that hypoxia resulting from OSA might have the capacity to impair the intestinal barrier prior to the induction of multisystem dysfunction.

Purpose: Our previous cross-sectional study showed that periodic limb movements during sleep (PLMS) were frequently found in patients with obstructive sleep apnea (OSA) and that both OSA and PLMS were associated with higher plasma fibrinogen levels. We explored the longitudinal relationships among these factors., Methods: Plasma fibrinogen levels were measured in 333 consecutive patients who underwent polysomnography to diagnose OSA. Patients who initiated continuous positive airway pressure (CPAP) underwent follow-up polysomnography after 3 months of CPAP use. They were categorized into groups with good or poor adherence (% days with ≥ 4 h/night of CPAP use ≥ 70% or < 70%, respectively). Changes in sleep parameters and plasma fibrinogen levels during the treatment period were compared between these groups., Results: The cross-sectional analysis of all reviewed 333 patients indicated that fibrinogen levels were associated with the severities of OSA and PLMS. The 60 patients (27 good and 33 poor adherence) who underwent follow-up polysomnography were included in the longitudinal analysis. The median (interquartile range) periodic limb movement index did not change significantly from CPAP titration to the 3-month follow-up (good adherence: 10.5 (0-23.8) to 10.8 (0-70.2) events/h, p = 0.21; poor adherence: 1.2 (0-14.3) to 0.8 (0-15.7) events/h, p = 0.67). However, the plasma fibrinogen level significantly decreased only in the good adherence group (good adherence: baseline 275 ± 46 to follow-up 255 ± 47 mg/dl, p < 0.01; poor adherence: 277 ± 52 to 284 ± 70 mg/dl, p = 0.48)., Conclusions: These results did not support a longitudinal association between PLMS and OSA. However, good adherence to CPAP could reduce plasma fibrinogen levels, thus ameliorating elevations in plasma fibrinogen as a risk factor for future cardiovascular events.

Purpose: Intermittent hypoxia in obstructive sleep apnea (OSA) resembles ischemia/reperfusion. Oxidative stress during ischemia/reperfusion increases matrix metalloproteinase-2 (MMP-2) activity and leads to adverse cardiovascular consequences in animal models, but there is scarce information about MMP-2 in humans with OSA. The aim of this study was to determine if serum MMP-2 levels of patients with OSA differ from controls and if MMP-2 activity correlates with the severity of OSA and level of hypoxemia., Methods: Patients with OSA (n = 124) were recruited from the Sleep Disorders Center (Saskatoon City Hospital, Canada) after in-lab polysomnography (PSG). Controls (n = 26) were subjects referred for PSG who did not have OSA. Severity of OSA was categorized according to American Academy of Sleep Medicine criteria. Level of hypoxemia was expressed as oxygen desaturation index (ODI; 3% desaturation). Gelatin zymography was performed to measure serum MMP-2 activity., Results: Serum MMP-2 activity was significantly higher in patients with OSA than in controls (p = 0.029). MMP-2 activity in patients with severe OSA was significantly higher than in those with mild/moderate OSA and controls (p = 0.002). Linear regression showed positive associations with MMP-2 activity in serum for AHI (p < 0.001) and ODI (p = 0.003). The associations persisted after adjustment for multiple confounders, including age, sex, BMI, and cardiovascular disease., Conclusions: Serum MMP-2 activity was associated with OSA severity, and level of hypoxemia in patients with OSA, suggesting MMP-2 is worth considering as a potential biomarker to be included in future studies on sets of biomarkers for hypoxemic insult in OSA.

Purpose: To evaluate the association of recently diagnosed obstructive sleep apnea (OSA) with TNF-α and IL-6 and to measure the effect of short-term continuous positive airway pressure (CPAP) therapy on these markers., Methods: A prospective, open-label, controlled trial was conducted among patients referred for diagnostic polysomnography (PSG). After PSG, patients were divided into 3 groups: OSA intervention group (N = 21), OSA control untreated group (N = 19), and non-OSA control group (N = 24). IL-6 and TNF-α levels were measured at baseline and 1 month after intervention. Repeated measures (RM) ANOVA and ANCOVA were used to compare the three groups regarding changes in TNF-α and IL-6 levels by analyzing between-subject and within-subject effects as a function of time and adjusting for significant covariates., Results: At baseline, IL-6 (p = 0.05) and TNF-α (p = 0.04) were significantly higher in the OSA patients than in the non-OSA controls. There was no effect of time either on the TNF-α (p = 0.069) or IL-6 (p = 0.717) after 1 month of CPAP. No interaction effect between group and time was found for either TNF-α (p = 0.240) or IL-6 (p = 0.552) after 1 month of CPAP. There was neither a group effect nor an interaction effect between group and time for either IL-6 or TNF α after adjusting for age, BMI, neck circumference, and AHI., Conclusion: This study showed increases in proinflammatory state as illustrated by plasma TNF-α and IL-6 levels among recently diagnosed OSA patients, but there were no changes in these inflammatory markers following 1-month CPAP therapy.

Purpose: Patients with obstructive sleep apnea syndrome (OSAS) have been found to exhibit lower serum vitamin D levels, even when the control groups are matched for confounding conditions. However, contradictory studies are also present. This study aimed to compare serum 25-hydroxyvitamin D (25(OH)D) levels between adult patients with OSAS and non-apneic controls and to evaluate the changes in 25(OH)D levels after 3 and 12 months of continuous positive airway pressure (CPAP) therapy., Methods: The study was comprised of 30 patients with OSAS and 30 controls. Serum 25(OH)D levels were determined at baseline and after 3 and 12 months of CPAP therapy in all patients with OSAS. For analysis, patients with OSAS were divided into subgroups by adherence, with adherence defined as CPAP usage for > 4 h per night on at least 70% of nights., Results: The 25(OH)D levels were not significantly different between OSAS and control groups at baseline. 25(OH)D levels did not change after 3 and 12 months of CPAP therapy. Patients who were CPAP-adherent showed less reduction in 25(OH)D levels compared with non-adherent ones (21.18 ± 9.3 vs. 12.13 ± 3.8 ng/mL, p = 0.022) after 1 year. The 25(OH)D levels were significantly correlated with higher daily CPAP usage at 3 and 12 months. Mean daily CPAP usage was a significant predictor of serum 25(OH)D levels at 12 months., Conclusions: Patients with OSAS who demonstrated good CPAP adherence showed significantly higher 25(OH)D levels after 1 year compared with those not adequately using CPAP. Long-term good CPAP adherence and highly daily CPAP usage positively affected 25(OH)D levels in patients with OSAS.

Purpose: To investigate the different pathophysiologies of obstructive sleep apnea (OSA) phenotypes using cluster analysis. Differences between leptin/adiponectin levels in the resulting OSA phenotypes were also examined., Methods: In total, 1057 OSA patients were selected, and a retrospective survey of clinical records, polysomnography results, and blood gas data was conducted. Patients were grouped into four clusters by their OSA severity, PaCO2, body mass index (BMI), and sleepiness. A k-means cluster analysis was performed, resulting in a division into four subpopulations. The Tukey or Games-Howell tests were used for intergroup comparisons., Results: Among the 20 clinical OSA items, four common factors (Epworth Sleepiness Scale [ESS], BMI, Apnea-Hypopnea Index [AHI], and PaCO2) were extracted by principal component analysis, and a cluster analysis was performed using the k-means method, resulting in four distinct phenotypes. The Clusters 1 (middle age, symptomatic severe OSA) and 4 (young, obese, symptomatic very severe OSA) exhibited high leptin levels. C-reactive protein levels were also elevated in Cluster 4, indicating a different pathophysiological background. No apparent differences between clusters were observed regarding adiponectin/leptin ratios and adiponectin levels. Classification into groups based on phenotype showed that Epworth Sleepiness Scale [ESS] score and disease severity were not correlated, suggesting that sleepiness is affected by multiple elements., Conclusions: The existence of multiple clinical phenotypes suggests that different pathophysiological backgrounds exist such as systemic inflammation and metabolic disorder. This classification may be used to determine the efficacy of continuous positive airway pressure treatment that cannot be determined by the AHI.

Background: Raftlin is a large, major lipid raft protein of cell membranes. Raftlin levels have not been previously examined in patients with obstructive sleep apnea (OSA). Our study aimed to evaluate the changes in raftlin, interleukin-6 (IL-6), interleukin-8 (IL-8), and tumor necrosis factor alpha (TNFα) values from the preoperative state to the third month postoperatively in patients undergoing expansion sphincter pharyngoplasty for OSA., Methods: Of 60 patients, 10 patients had mild OSA (AHI 5-14), 10 moderate (AHI 15-29), 10 severe (AHI ≥ 30), and 30 with AHI < 5 formed a control group. Preoperatively and at 3 months post-operatively, IL-6, IL-8, TNFα, and raftlin values were measured., Results: Preoperatively, mean raftlin levels were 914.4 ± 62.7 pg/mL for controls, 910.0 ± 42.5 pg/mL in mild, 1000.5 ± 63.3 pg/mL in moderate, and 1386.3 ± 101.4 pg/mL in severe groups, with moderate and severe groups significantly elevated compared to controls (p < 0.001). Preoperatively to 3 months post-operatively, raftlin levels decreased significantly in each OSA group (p < 0.05). Levels of IL-6, IL-8 and TNFα followed similar patterns at baseline and after surgical intervention., Conclusions: Raftlin levels at the third postoperative month decreased significantly compared with preoperative levels in parallel with other markers of inflammation.

Purpose: Obstructive sleep apnea (OSA) is a disorder characterized by recurrent episodes of obstruction of the upper respiratory tract during sleep often accompanied by oxygen desaturations. Antioxidant defense mechanisms are important to prevent OSA-associated diseases and decrease mortality. We aimed to determine the levels of selenium and vitamins A, C, and E in patients with OSA but without any comorbidities and compare the results with a control group, theorizing that the findings may be helpful to understand the antioxidant mechanisms in the pathogenesis of OSA and associated diseases., Methods: We designed a case-control study with 146 subjects. Subjects were categorized into four groups by apnea-hypopnea index (AHI) scores: control (n = 32; AHI < 5), mild OSA (n = 32; 5 ≤ AHI < 15), moderate OSA (n = 34; 15 ≤ AHI < 30), and severe OSA (n = 48; AHI ≥ 30) groups. Serum levels of selenium were measured by atomic absorption spectrometer. Vitamin A, C, and E levels were measured by high-performance liquid chromatography and ultraviolet (HPLC-UV) detector., Results: After adjusting for age, BMI, and gender, serum selenium and vitamin A levels were found to be higher in patients with OSA compared with controls (ANCOVA, p < 0.008, and p = 0.014 respectively), and levels of these markers increased with the severity of the disease. AHI was positively correlated with selenium (r = 0.289; p < 0.001), and vitamin A levels (r = 0.276; p < 0.001)., Conclusion: These results demonstrated that antioxidant response with increased vitamin A, and selenium concentrations, may be important defense mechanisms in patients with OSA patients who do not have other comorbidities. Antioxidant nutrients or supplements may be implemented as a complementary treatment of OSA to support antioxidant defense.

The processes of free radical lipid oxidation were studied in 47 patients with moderate to severe obstructive sleep apnea syndrome before and after 1-month course of CPAP-therapy (continuous positive airway pressure). The control group consisted of 13 people without clinically confirmed apnea. The material for the study was serum, blood plasma, and erythrocyte hemolysate. The levels of LPO products and antioxidant defense were determined spectrophotometrically and spectrofluorometrically. The changes revealed in patients with obstructive sleep apnea syndrome after CPAP therapy indicate a decrease in the intensity of LPO and restoration of the balance in the "LPO-antioxidant defense" system.

Purpose: The pathogenesis of cardiovascular disease (CVD) in patients with obstructive sleep apnea (OSA) is unclear. Several studies have suggested that CVD may be caused by oxidative stress from chronic intermittent hypoxia and associated vascular endothelial dysfunction. Oxidative stress in patients with OSA can induce endothelial cell apoptosis, aggravate vascular endothelial damage, and promote the expression of redox-sensitive genes and adhesion molecules. No meta-analysis has explored whether or not OSA is related to nitric oxide (NO)., Method: To assess the association between serum/plasma NO levels and OSA, we performed a meta-analysis of the literature on the subject to grade the strength of evidence., Results: OSA was significantly related to decreased serum or plasma NO levels (WMD = - 11.66, 95% CI - 17.21 to - 6.11; P < 0.01). Among the studies analyzed, there was high degree of heterogeneity (I 2 = 79%, P < 0.01). Sensitivity analysis showed that after omitting any single study or converting a random effects model (REM) to a fixed effects model (FEM), the main results still held., Conclusions: This meta-analysis suggests a strong correlation between OSA and serum or plasma NO levels which may explain the link between intermittent hypoxia of OSA and risk of CVD. The strength of this finding may spur further basic and clinical research into vascular endothelial dysfunction in patients with OSA.

Objective: Adropin is a recently discovered peptide hormone that plays a vital role in metabolism and cardiovascular-cerebrovascular function. The purpose of this study is to investigate the role of circulating adropin levels in patients with obstructive sleep apnea-hypopnea syndrome (OSAHS) and further determine the relationship between serum adropin concentration and endothelial dysfunction in patients with OSAHS., Methods: Forty polysomnography-diagnosed patients with OSAHS and 21 age and sex-matched healthy controls were enrolled in the current study. Serum adropin level, endothelial function parameters including flow-mediated dilatation (FMD) of brachial artery, endothelin-1 (ET-1), and nitric oxide (NO) were measured in all participants., Results: Serum adropin levels were significantly lower in patients with OSAHS compared to the control subjects. FMD was lower and serum ET-1 levels were higher in patients with OSAHS compared to control subjects. No significant difference was seen in serum NO levels between the two groups. Multivariate linear regression analysis revealed that serum adropin level was positively associated with FMD and negatively correlated with AHI. Additionally, serum adropin levels were lower in patients with OSAHS who had endothelial dysfunction compared with those patients without endothelial dysfunction. The receiver operating characteristic (ROC) analysis showed that area under the curve (AUC) for serum adropin in predicting endothelial dysfunction status in patients with OSAHS was 0.815 (95% CI 0.680-0.951, p = 0.001). The cutoff value of serum adropin level was less than 235.0 pg/mL, which provided the sensitivity and specificity of 81% and 75%, respectively, for the detection of endothelial dysfunction in patients with OSAHS., Conclusion: Lower circulating adropin levels are closely associated with endothelial dysfunction in patients with OSAHS. Circulating adropin level may serve as an early biomarker to predict the development of endothelial dysfunction before the emergence of clinical symptoms in patients with OSAHS.

Purpose: Obstructive sleep apnea-hypopnea syndrome (OSAHS) may cause pulmonary diseases, and periostin plays an important role on the development of pulmonary diseases. In addition, periostin and pro-inflammatory cytokine TNF-α can regulate each other in vivo. This study aimed to observe the changes of serum periostin and TNF-α levels in patients with OSAHS compared with healthy volunteers and to investigate their correlation., Methods: A convenience sample of 67 patients with OSAHS in our hospital from December 2018 to December 2019 was selected and categorized into mild, moderate, and severe groups according to apnea-hypopnea index by polysomnography. In addition, 21 healthy volunteers were selected as the control group. Serum levels of periostin and TNF-α were determined by enzyme-linked immunosorbent assay (ELISA). Results were analyzed using the SPSS software., Results: Both serum periostin and TNF-α levels in all the three OSAHS groups were higher than those of the control group and increased with severity of OSAHS. The severe group had significantly higher serum periostin and TNF-α levels than the mild and moderate groups (p < 0.05). For patients with OSAHS, serum periostin and TNF-α levels positively correlated with the apnea-hypopnea index (AHI) (p < 0.01) and negatively correlated with the lowest saturation oxygen (LSaO 2 ) and mean saturation oxygen (MSaO 2 ) (both p < 0.01). In addition, there was a positive correlation between serum periostin and TNF-α levels in patients with OSAHS (p < 0.001)., Conclusions: Serum periostin and TNF-α levels were significantly increased in patients with OSAHS and may serve as a potential biomarker for severity of OSAHS. These findings suggest that it may be fruitful to study the role of periostin and TNF-α in OSAHS-induced pulmonary diseases.

Objective and Aim: Ischemia-modified albumin (IMA) is a newly recognized marker of chronic inflammation used to evaluate oxidative stress status in patients with various diseases. We explored the possible relationship between IMA levels and obstructive sleep apnea (OSA)., Methods: In this retrospective study, 169 of 216 sequential patients being evaluated for suspicion of OSAS met inclusion criteria. Polysomnography confirmed OSA in 86 patients (51%) while 81 patients (49%) without OSA were categorized as control subjects. All study participants were tested for blood IMA level, neutrophil/lymphocyte ratio (NLR), C-reactive protein (CRP) level, and red blood cell distribution width (RDW)., Results: The serum IMA level was significantly higher in patients with OSAS than controls (p = 0.008). The serum IMA level increased significantly as OSAS severity increased (r = 0.50, p < 0.001) and was positively correlated with the AHI (r = 0.41, p < 0.001), CRP level (r = 0.31, p = 0.004), body mass index (r = 0.24, p = 0.022), RDW (r = 0.31, p = 0.03), oxygen desaturation index (ODI) (r = 0.22, p = 0.02), and negatively correlated with the hemoglobin concentration (r = - 0.28, p = 0.04) and minimum hemoglobin oxygen saturation (SpO2) (r = - 0.25, p = 0.02). Receiver operator curve (ROC) analysis showed that the optimal serum IMA, CRP, RDW, and NLR values were not different for predicting OSAS diagnosis (areas under the curves (AUC) = 0.62, 0.59, 0.60, and 0.43, respectively). However, the serum IMA level was superior in reflecting OSAS severity (AUC = 0.78) compared to CRP, RDW, and NLR values (AUC = 0.61, 0.53, and 0.51, respectively) (all p < 0.001)., Conclusion: Like other markers of inflammation, blood IMA levels were significantly elevated in patients with OSA. However, blood IMA level was a better predictor of disease severity than the other markers.

Background: To examine if selected demographic (age, gender), clinical (diabetes, coronary artery disease, hyperlipidemia, myocardial infarction, stroke, lung disease, smoking history, alcohol intake), and biomarker [blood pressure (BP), heart rate, body mass index (BMI), neck circumference, Mallampati score] variables are predictors of apnea-hypopnea index (AHI) from polysomnography (PSG)., Methods: This cross-sectional study recruited a sample of adults (N = 170) who were being evaluated for OSA. Participants completed self-reported demographic and clinical questionnaires, and then completed PSG (n = 142). Multi-collinearity was assessed. Confounding factors, correlations, and potential interactions were explored., Results: The final regression model was performed on 130 participants; 61 (46.9%) had an AHI ≥ 15. Systolic and diastolic BPs were highly correlated. Interactions were tested between gender and other variables (high cholesterol, BMI, neck circumference, systolic BP) and between systolic BP and other variables (high cholesterol, BMI, neck circumference, and lung disease). No interactions occurred between gender or systolic BP and other variables, meaning that the effects of the variables on AHI levels from PSG did not vary depending on gender or systolic BP. BMI, systolic BP, and absence of lung disease were predictors for AHI levels ≥ 15 from PSG., Conclusions: BMI and systolic BP were significant predictors of OSA in this study. The absence of lung disease as a significant predictor was unique and may be due to the small number of participants who self-reported lung disease. To our knowledge, this is the first study to report this combination of variables to predict AHI levels ≥ 15 from PSG.

Purpose: To evaluate whether a predictive model based on nocturnal minimal oxygen saturation (SpO 2 ) alone can accurately detect the presence of obstructive sleep apnea (OSA) in a population with suspected OSA., Methods: A total of 4297 participants with suspected OSA were enrolled in this study, and laboratory-based polysomnography (PSG) tests were performed at sea level in all subjects. Nocturnal minimal SpO 2 was obtained automatically as part of the PSG test. Stratified sampling was used to divide the participants' data into the training set (75%) and the test set (25%). An OSA detection model based on minimal SpO 2 alone was created using the training set data and its performance was evaluated using the independent test set data ("hold-out" evaluation). Gender-specific models, and models based on minimal SpO 2 in combination with other predictive factors (age, body mass index, waist-to-hip ratio, snoring grade, Epworth Sleepiness Scale score, and comorbidities), were also created and compared in terms of OSA detection performance., Results: The prevalence of OSA was 85.6% in our study population. The models including multiple predictors, and the gender-specific models, failed to outperform the model based solely on minimal SpO 2 , which showed good predictive performance (C statistic, 0.922) having an overall accuracy rate of 0.86, sensitivity of 0.87, specificity of 0.84, positive predictive value of 0.97, and positive likelihood ratio of 5.34. In addition, the model based on minimal SpO 2 alone could also accurately predict the presence of moderate-to-severe OSA and severe OSA, with C statistics of 0.914 and 0.900, respectively., Conclusions: A predictive model based on nocturnal minimal SpO 2 alone may be an alternative option to detect the presence of OSA in a high-risk population when standard diagnostic tests are unavailable.

Purpose: Obstructive sleep apnoea (OSA) involves recurrent obstructive apnoeas and hypopnoeas which cause cyclic hypoxia, reoxygenation and formation of reactive oxygen species (ROS). We aimed to investigate a member of the nicotinamide adenine dinucleotide phosphate oxidase (NOX) family of enzymes, specifically (NOX4), not previously studied in humans, as well as 8-OHdG/106dG, MDA and IMA, which are known to be associated with oxidative stress. We also evaluated these parameters in predicting the presence and severity of OSA., Methods: All 120 subjects (90 with OSA, 30 healthy controls) underwent polysomnography and had blood serum samples taken at the same time of day. Subjects were grouped by presence and severity of OSA, and serum markers were compared among groups., Results: Age and body mass index were not significantly different among groups. In the OSA group, the levels of NOX4, IMA, MDA and 8-OHdG/106dG were significantly higher than in the healthy control group. NOX4 and other parameters were positively correlated with the severity of OSA. For all parameters, the highest levels were detected in patients with severe OSA., Conclusions: The repeated hypoxia of OSA is associated with increases in the serum levels of inflammatory mediators such as MDA, IMA and 8-OHdG/106dG and the ROS NOX4. In this study, NOX4 and other markers were associated with the presence and severity of OSA.

Purpose: The current study was conducted to explore the clinical features and risk factors of patients with asthma complicated by obstructive sleep apnea-hypopnea syndrome (OSAHS)., Methods: Patients with asthma who underwent polysomnography in our hospital from August 2017 to December 2019 were enrolled in the study. Data on demographics, pulmonary function testing, polysomnography, blood gases, mean pulmonary artery pressure, and vascular endothelial growth factor (VEGF) were compared between the two groups., Results: Of 238 patients with asthma, 93 who also had OSAHS formed the observation group and were subclassified into mild (n = 33), moderate (n = 41), and severe (n = 19) categories, while 145 patients with asthma alone were assigned to the control group. No significant differences were found in sex, age, course of disease, or pulmonary function between the two groups (P > 0.05), while the observation group showed more frequent allergic rhinitis and had greater BMI, neck circumference, mean pulmonary artery pressure (mPAP), and VEGF than those in the control group (P < 0.001). The peak expiratory flow (PEF), forced expiratory volume in 1 s (FEV 1 ), forced vital capacity (FVC), and FEV 1 /FVC in the mild group and the moderate group were higher than those in the severe group (P < 0.001). The durations of AHI and SaO 2  < 90% in the mild group and the moderate group were shorter than that in the severe group, and the lowest level of SaO 2 in the mild group and the moderate group was higher than that in the severe group (P <  0.05). The mPAP and VEGF of the mild and moderate groups were lower than those of severe group (P < 0.001), with mild group lower than moderate group (P < 0.001)., Conclusion: Significant differences in allergic rhinitis, BMI, neck circumference, AHI, SaO2, mPAP, and VEGF were observed in patients with asthma complicated by OSAHS. These parameters are risk factors associated with asthma complicated by OSAHS.

Purpose: Obstructive sleep apnea (OSA) is independently associated with increased risk for stroke and other cardiovascular diseases. Since activated platelets play an important role in cardiovascular disease, the objective of this study was to determine whether platelet reactivity was altered in OSA subjects with intermittent nocturnal hypoxemia., Methods: Thirty-one subjects, without hypertension or cardiovascular disease and not taking medication, participated in the study. Subjects were stratified based on OSA-related oxygen desaturation index (ODI) recorded during overnight polysomnography. Platelet reactivity to a broad panel of agonists (collagen, thrombin, protease-activated receptor1 hexapeptide, epinephrine, ADP) was measured by monitoring platelet aggregation and ATP secretion. Expression of platelet activation markers CD154 (CD40L) and CD62P (P-selectin) and platelet-monocyte aggregates (PMA) was quantified by flow cytometry., Results: Epinephrine-induced platelet aggregation was substantially decreased in OSA subjects with significant intermittent hypoxemia (ODI ≥ 15) compared with subjects with milder hypoxemia levels (ODI < 15) (area under curve, p = 0.01). In addition, OSA subjects with ODI ≥ 15 exhibited decreased thrombin-induced platelet aggregation (p = 0.02) and CD40L platelet surface expression (p = 0.05). Platelet responses to the other agonists, CD62P platelet surface expression, and PMA levels were not significantly different between groups. Reduction in platelet responses to epinephrine and thrombin, and decreased CD40L surface marker expression in significant hypoxemic OSA individuals, is consistent with their platelets being in an activated state., Conclusions: Increased platelet activation was present in otherwise healthy subjects with intermittent nocturnal hypoxemia due to underlying OSA. This prothrombotic milieu in the vasculature is likely a key contributing factor toward development of thrombosis and cardiovascular disease., Trial Registration: NCT00859950.

Background: Cardiovascular diseases (CVDs) are highly prevalent in obstructive sleep apnea (OSA), and dyslipidemia is an important factor. Atherogenic index of plasma (AIP, log[TG/HDL-C]) and apolipoproteinB to apolipoproteinAI ratio (apoB/apoAI ratio) are considered high quality predictors of cardiovascular risk. However, the associations between OSA severity and AIP and apoB/apoAI ratio remained unclear., Methods: A retrospective study was performed in 284 patients. Subjects were assessed with polysomnography (PSG) test, and OSA severity was defined by AHI. Data collected included anthropometric measurements, medical history, sleep parameters, fasting plasma lipids, fasting blood glucose, and insulin., Results: Participants were classified based on AHI into the following groups: control group (n = 28), mild group (n = 52), moderate group (n = 53), and severe group (n = 151). Triglyceride (TG), high-density lipoprotein cholesterol (HDL-C), apoAI, AIP, apoB/apoAI ratio (low-density lipoprotein cholesterol), LDL-C/HDL-C ratio, and HDL-C/apoAI ratio showed statistical significance among AHI subgroups (P < 0.05). The Pearson correlation analysis revealed that AIP (r = 0.32, P < 0.001) and apoB/apoAI ratio (r = 0.24, P < 0.001) were positively related to AHI. By multivariate linear regression analysis, we found that AHI was independently related to AIP (β = 0.24, P = 0.001), apoB/apoAI ratio (β = 0.24, P<0.001)., Conclusion: AHI was independently correlated with AIP and apoB/apoAI ratio in OSA. Our findings suggested that AIP and apoB/apoAI ratio increased with OSA severity, which might be partly responsible for the high risk of CVDs in OSA.

Objective: This study aimed to determine the association between the severity of obstructive sleep apnea (OSA) and serum Clara cell protein (CC16) levels in non-smoking patients with OSA., Methods: This prospective study included non-smoking patients who presented with sleep-related disturbances and underwent polysomnography (PSG). The serum CC16 level was measured and its relationship to PSG parameters was investigated., Results: The study included 128 patients (83 men) with a mean age of 48.4 ± 11.9. OSA was detected in 66 men (70%) and 29 women (30%) (p = 0.051). The severity of OSA was mild in 32 (25%), moderate in 28 (22%), and severe in 35 (27%) of the patients. There was no significant difference in CC16 levels between the OSA group (1746 ± 1006) and the OSA negative group (1721 ± 1201, p = 0.91) levels. There was no significant difference between the CC16 levels of the each four groups. Mean serum CC16 levels were significantly lower in OSA negative men than OSA positive men (777 vs 1462, p = 0.005). No significant difference was observed in CC16 values according to OSA severity in women., Conclusion: The serum CC16 level does not differ between non-smoking OSA patients and OSA negative patients.

Background: Obstructive sleep apnea (OSA) has been demonstrated to be associated with an increase of oxidative stress. However, whether circulating malondialdehyde (MDA), a widely used biomarker of oxidative stress, could be reduced by the treatment of OSA by continuous positive airway pressure (CPAP) is debated. The present meta-analysis was performed to determine the effect of CPAP treatment on circulating MDA among patients with OSA., Methods: A systematic search of PubMed, Embase, and Web of Science was performed for literature covering the period between 1967 and August 2019. Standardized mean difference (SMD) was calculated to estimate the treatment effects of pre- and post-CPAP therapy., Results: A total of 10 studies with 220 patients were included in this meta-analysis. A significant decrease in circulating MDA was observed after CPAP treatment (SMD = 1.164, 95% CI = 0.443 to 1.885, z = 3.16, p = 0.002) in OSA patients. Subgroup analyses revealed that CPAP therapy was associated with a significant decrease of circulating MDA in elder (SMD = 1.629, 95% CI = 0.265 to 2.994, z = 2.34, p = 0.019), more obese patients (SMD = 0.954, 95% CI = 0.435 to 1.473, z = 3.61, p = 0.000), more severe OSA patients (SMD = 0.879, 95% CI = 0.421 to 1.336, z = 3.76, p = 0.000), patients with therapeutic duration ≥ 3 months (SMD = 1.867, 95% CI = 0.563 to 3.172, z = 2.80, p = 0.005), and patients with good compliance (SMD = 1.004, 95% CI = 0.703 to 1.305, z = 6.54, p = 0.000)., Conclusions: This meta-analysis suggested that CPAP therapy exerted significant lowering effects on circulating MDA, especially in elder, more obese, and more severe OSA patients and patients with good compliance as well as longer duration of CPAP application.

Purpose: Obstructive sleep apnea (OSA) is associated with multiple comorbid conditions including cardiovascular diseases and cancer. There is a growing interest in exploring biomarkers to understand the related mechanisms and improve the risk stratification of OSA. Circulating microRNAs (miRNAs) are single noncoding strands of nearly 22 nucleotides that posttranscriptionally regulate target gene expression. Our aim was to identify miRNA profiles associated with OSA., Methods: We studied 48 male subjects, mostly Caucasian (63%) and overweight, divided by polysomnography into the no OSA control group (n = 6), mild OSA group (n = 12), moderate OSA group (n = 15), and severe OSA group (n = 15). The study groups were matched for age, body mass index (BMI), and body fat composition. miRNA profiles were measured from peripheral whole blood using two steps: (1) microarray analysis comprising more than 2500 miRNAs in a subsample of 12 subjects (three from each group); and (2) validation phase using real-time quantitative polymerase chain reaction (RTqPCR)., Results: The microarray assessment identified 21 differentially expressed miRNAs among the groups. The RT-qPCR assessment showed that miR-1254 and miR-320e presented a gradual increase in expression parallel to OSA severity. Linear regression analysis showed that severe OSA was independently associated with miR-1254 (ß = 68.4; EP = 29.8; p = 0.02) and miR-320e (ß = 76.1; EP = 31.3; p = 0.02)., Conclusion: Severe OSA is independently associated with miRNAs that are involved in heart failure (miR-1254), myocardial ischemia/reperfusion (miR-320e), and cell proliferation in some cancer types (miR-1254 and miR-320e). Future investigations addressing whether these miRs may provide prognostic information in OSA are needed.

Purpose: Continuous positive airway pressure (CPAP) is an effective treatment for obstructive sleep apnea (OSA). However, studies provide conflicting results on the effects of CPAP on subcutaneous adipose tissue (SAT) in patients with OSA. We therefore performed a meta-analysis to evaluate whether or not CPAP has an effect on SAT in patients with OSA., Methods: Studies were retrieved by searching the Cochrane Library, Web of Science, Embase, and Pubmed. Information on study and patient characteristics, study design, and SAT pre- and post-CPAP treatment was extracted for analysis. Different methods for measurement of SAT were also notated. Standardized mean difference (SMD) and 95% confidence interval (CI) were measured to estimate the change in SAT before and after CPAP treatment. Meta-analysis was performed using the RevMan v.5.3 and Stata 14.0., Results: A total of 10 studies met inclusion criteria encompassing 309 patients in the final analysis. The pooled estimate showed that CPAP treatment resulted in no significant change in SAT (SMD = - 0.014, 95% CI = - 0.161 to 0.133, p = 0.896). Meta-regression analyses revealed no predictor, including methods of measuring SAT, that influenced the CPAP effect on SAT., Conclusion: Our meta-analysis demonstrated that after CPAP therapy, there was no significant change in SAT in patients with OSA.