Oxidative Stress Markers among Obstructive Sleep Apnea Patients

Explainable Deep Learning Approaches for Risk Screening of Periodontitis

Several pieces of evidence have been reported regarding the association between periodontitis and systemic diseases. Despite the emphasized significance of prevention and early diagnosis of periodontitis, there is still a lack of a clinical tool for early screening of this condition. Therefore, this study aims to use explainable artificial intelligence (XAI) technology to facilitate early screening of periodontitis. This is achieved by analyzing various clinical features and providing individualized risk assessment using XAI. We used 1,012 variables for a total of 30,465 participants data from National Health and Nutrition Examination Survey (NHANES). After preprocessing, 9,632 and 5,601 participants were left for all age groups and the over 50 y age group, respectively. They were used to train deep learning and machine learning models optimized for opportunistic screening and diagnosis analysis of periodontitis based on Centers for Disease Control and Prevention/ American Academy of Pediatrics case definition. Local interpretable model-agnostic explanations (LIME) were applied to evaluate potential associated factors, including demographic, lifestyle, medical, and biochemical factors. The deep learning models showed area under the curve values of 0.858 ± 0.011 for the opportunistic screening and 0.865 ± 0.008 for the diagnostic dataset, outperforming baselines. By using LIME, we elicited important features and assessed the combined impact and interpretation of each feature on individual risk. Associated factors such as age, sex, diabetes status, tissue transglutaminase, and smoking status have emerged as crucial features that are about twice as important than other features, while arthritis, sleep disorders, high blood pressure, cholesterol levels, and overweight have also been identified as contributing factors to periodontitis. The feature contribution rankings generated with XAI offered insights that align well with clinically recognized associated factors for periodontitis. These results highlight the utility of XAI in deep learning-based associated factor analysis for detecting clinically associated factors and the assistance of XAI in developing early detection and prevention strategies for periodontitis in medical checkups.

The impact of chronic intermittent hypoxia on enzymatic activity in memory-associated brain regions of male and female rats

Background

Obstructive sleep apnea (OSA) is an intermittent hypoxia disorder associated with cognitive dysfunction, including learning and memory impairments. There is evidence that alterations in protease activity and neuronal activation as associated with cognitive dysfunction, are dependent on sex, and may be brain region-specific. However, the mechanisms mediating OSA-induced cognitive impairments are unclear. Therefore, we used a rat model of OSA, chronic intermittent hypoxia (CIH), to investigate protease activity (e.g., calpain and caspase-3) and neuronal activation (early growth response protein 1, EGR-1) in brain regions associated with learning and memory. We used a rat model of OSA known as chronic intermittent hypoxia (CIH) to investigate protease activity (calpain and caspase-3) and neuronal activation (early growth response protein 1, EGR-1) in brain regions associated with learning and memory.

Methods

Male and female Sprague Dawley rats were exposed to CIH or room air (normoxic) for 14 days. We quantified protease activity and cleaved spectrin products, along with EGR-1 protein expression in hippocampal subregions (CA1, CA3), cortical regions [entorhinal cortex (ETC), retrosplenial cortex (RSC), cerebellar cortex (CC)], and subcortical regions [raphe nucleus (RN), locus coeruleus (LC)] associated with learning and memory. Within each group, Pearson correlations of calpain activity, caspase-3 activity, and EGR-1 expression were performed between brain regions. Sex differences within normoxic and CIH correlations were examined.

Results

CIH dysregulated calpain activity in male ETC and female CA1 and RSC. CIH dysregulated caspase-3 activity in male RN and female CA1 and RSC. CIH decreased calpain and caspase-3 cleavage products in male ETC. CIH decreased calpain-cleaved spectrin in male RSC but increased these products in female RSC. EGR-1 expression was decreased in male and female RN. Correlational analysis revealed CIH increased excitatory connections in males and increased inhibitory connections in females. EGR-1 expression in males shifted from negative to positive correlations.

Conclusions

Overall, these data show that CIH dysregulates protease activity and impairs neuronal function in a brain region- and sex-dependent manner. This indicates that males and females exhibit sex-specific vulnerabilities to mild OSA. These findings concur with our previous behavioral studies that demonstrated memory impairment in CIH-exposed rats.

Expiratory muscle strength training reduces oxidative stress and systemic inflammation in men with obstructive sleep apnea syndrome: a double-blinded, randomized parallel trial

STUDY OBJECTIVES

This study aimed to evaluate and compare the effects of high and low-intensity expiratory muscle strength training (EMST) on disease severity, systemic inflammation, oxidative stress, respiratory muscle strength, exercise capacity, symptoms, daytime sleepiness, fatigue severity, and sleep quality in male patients with obstructive sleep apnea syndrome (OSAS).

METHODS

Thirty-one male patients diagnosed with moderate OSAS were included in this double-blind, randomized, parallel study. Patients were randomized into two groups: High-EMST and Low-EMST groups. EMST was used at home 7 days/week, once a day, for 25 breaths, 12 weeks. Respiratory muscle strength was measured using a mouth pressure device. Disease severity (Apnea-Hypopnea Index [AHI]) and, respiratory sleep events by polysomnography, total oxidant level(TOS), total antioxidant level(TAS), oxidative stress index (OSI), C-reactive protein (CRP), tumor necrosis factor-alpha (TNF-α), interleukin-6 (IL-6), and interleukin-10 (IL-10) levels by blood serum were evaluated.

RESULTS

The percentage of AHI change in the high-EMST group(50.8%) was significantly higher than in the low-EMST group(6.3%; p = .002, d = 1.31). In general, as MEP increased by one unit, AHI decreased by 0.149 points (b = -0.149; CR = -3.065; p = .002), and as AHI increased by one unit, ODI increased by 0.746 points (b = 0.746; CR = 10.604; p < .001). TOS, OSI, TNF-α and IL-6 levels decreased at similar rates in both groups.

CONCLUSIONS

EMST significantly reduces systemic inflammation and oxidative stress while improving expiratory muscle strength in male patients with moderate OSAS. High-EMST is more effective in enhancing the severity of disease than low-EMST. EMST is a practical, effective, and promising treatment for pulmonary rehabilitation in patients with moderate OSAS.

CLINICAL TRIALS

Effect of EMST systemic inflammation and oxidative stress in patients with moderate OSAS, https://clinicaltrials.gov/study/NCT05242406, with the number NCT05242406.

The Role of Oxidative Stress and the Potential Therapeutic Benefits of Aronia melanocarpa Supplementation in Obstructive Sleep Apnea Syndrome: A Comprehensive Literature Review

Obstructive sleep apnea (OSA) is a sleep disorder characterized by repeated episodes of apnea and hypopnea, leading to inflammation and oxidative stress that contribute to numerous health complications, including cardiovascular diseases. Continuous positive airway pressure (CPAP) is a standard for treating OSA and is effective in reducing inflammation and oxidative stress. Aronia melanocarpa (a black chokeberry), a deciduous shrub belonging to the Rosaceae family and native to eastern North America that is rich in polyphenols, has garnered attention for its therapeutic potential due to its ability to neutralize reactive oxygen species (ROS) and modulate inflammatory pathways, such as NF-κB. This review supports the hypothesis that combining CPAP with black chokeberry supplementation might provide a more comprehensive approach to treating OSA, reducing the risk of health complications by further reducing oxidative stress. In conclusion, Aronia melanocarpa has potential benefits as an adjunct therapy in the treatment of OSA, enhancing overall health and well-being. This review compiles the latest scientific findings on the benefits of black chokeberry supplementation, its application in OSA treatment, and its potential use in the treatment of other conditions linked to oxidative stress.

The role of Klotho and sirtuins in sleep-related cardiovascular diseases: a review study

The prevalence of sleep disorders has been reported from 1.6% to 56.0%, worldwide. Sleep deprivation causes cardiovascular diseases (CVDs) including atherosclerosis, vascular aging, hypertension, heart dysfunction, reduced heart rate variability, and cardiac arrhythmia. Reduced tissue oxygen causes various CVDs by activating pro-inflammatory factors and increasing oxidative stress. Sleep disorders are more important and prevalent in older people and cause more severe cardiovascular complications. On the other hand, the reduction of Klotho level, an age-dependent protein whose expression decreases with age, is associated with age-related diseases. Sirtuins, class III histone deacetylases, also are among the essential factors in postponing cellular aging and increasing the lifespan of organisms, and they do this by regulating different pathways in the cell. Sirtuins and Klotho play an important role in the pathophysiology of CVDS and both have anti-oxidative stress and anti-inflammatory activity. Studies have shown that the levels of Klotho and sirtuins are altered in sleep disorders. In this article, alterations of Klotho and sirtuins in sleep disorders and in the development of sleep-related CVDs were reviewed and the possible signaling pathways were discussed. The inclusion criteria were studies with keywords of different types of sleep disorders and CVDs, klotho, SIRT1-7, and sirtuins in PubMed, Scopus, Embase، Science Direct، Web of Sciences and Google Scholar by the end of 2023. The studies revealed there is a bidirectional relationship between sleep disorders and the serum and tissue levels of Klotho and sirtuins and sleep related-CVDs.

Obstructive Sleep Apnea is a Risk Factor for Incident COVID-19 Infection

Cross-sectional studies suggest that obstructive sleep apnea (OSA) is a potential risk factor for incident COVID-19 infection, but longitudinal studies are lacking. In this study, two surveys from a large general population cohort, the COVID-19 Outbreak Public Evaluation (COPE) Initiative, undertaken 147 ± 58 days apart were analyzed to determine whether the pre-existing OSA was a risk factor for the incidence of COVID-19. Of the 24,803 respondents completing the initial survey, 14,950 were negative for COVID-19; data from the follow-up survey were available for 2,325 respondents. Those with incident COVID-19 infection had a slightly higher prevalence of OSA (14.3 vs. 11.5%, p=0.068). Stratification by treatment status revealed that those untreated for their OSA were at greater risk for developing COVID-19 infection (OSA Untreated, 14.2 vs. 7.4%, p≤0.05). In a logistic regression model adjusted for comorbidities, demographic and socioeconomic factors and the interaction between vaccination status and OSA, incident COVID-19 infection was 2.15 times more likely in those with untreated OSA (aOR: 2.15, 95% CI: 1.18-3.92, p≤0.05). Stratification by treatment status revealed only untreated OSA participants were at greater risk for COVID-19 (aOR: 3.21, 95% CI: 1.25-8.23, p≤0.05). The evidence from this study confirms untreated OSA as a risk factor for acquiring COVID-19 infection and highlights the importance of actively treating and managing OSA as a preventative mechanism against COVID-19 disease.

Role of Oxidative Stress in the Occurrence and Development of Cognitive Dysfunction in Patients with Obstructive Sleep Apnea Syndrome

Obstructive sleep apnea syndrome (OSAS) causes recurrent apnea and intermittent hypoxia at night, leading to several complications such as cognitive dysfunction. However, the molecular mechanisms underlying cognitive dysfunction in OSAS are unclear, and oxidative stress mediated by intermittent hypoxia is an important mechanism. In addition, the improvement of cognitive dysfunction in patients with OSAS varies by different treatment regimens; among them, continuous positive airway pressure therapy (CPAP) is mostly recognized for improving cognitive dysfunction. In this review, we discuss the potential mechanisms of oxidative stress in OSAS, the common factors of affecting oxidative stress and the Links between oxidative stress and inflammation in OSAS, focusing on the potential links between oxidative stress and cognitive dysfunction in OSAS and the potential therapies for neurocognitive dysfunction in patients with OSAS mediated by oxidative stress. Therefore, further analysis on the relationship between oxidative stress and cognitive dysfunction in patients with OSAS will help to clarify the etiology and discover new treatment options, which will be of great significance for early clinical intervention.

Association of Obstructive Sleep Apnea with Nonalcoholic Fatty Liver Disease: Evidence, Mechanism, and Treatment

Obstructive sleep apnea (OSA), a common sleep-disordered breathing condition, is characterized by intermittent hypoxia (IH) and sleep fragmentation and has been implicated in the pathogenesis and severity of nonalcoholic fatty liver disease (NAFLD). Abnormal molecular changes mediated by IH, such as high expression of hypoxia-inducible factors, are reportedly involved in abnormal pathophysiological states, including insulin resistance, abnormal lipid metabolism, cell death, and inflammation, which mediate the development of NAFLD. However, the relationship between IH and NAFLD remains to be fully elucidated. In this review, we discuss the clinical correlation between OSA and NAFLD, focusing on the molecular mechanisms of IH in NAFLD progression. We meticulously summarize clinical studies evaluating the therapeutic efficacy of continuous positive airway pressure treatment for NAFLD in OSA. Additionally, we compile potential molecular biomarkers for the co-occurrence of OSA and NAFLD. Finally, we discuss the current research progress and challenges in the field of OSA and NAFLD and propose future directions and prospects.

Association of healthy lifestyle with self-reported sleep disordered breathing: A cross-sectional study

Some healthy lifestyle components have been linked with sleep disordered breathing (SDB), yet little is known about the relationship between comprehensive lifestyle factors and SDB. This study aimed to examine the healthy lifestyle with SDB in community-dwelling adults. We conducted a cross-sectional analysis of the Suzhou Food Consumption and Health Survey in China between 2018 and 2020. The healthy lifestyle index (HLI) was created by combining smoking, alcohol drinking, diet, physical activity, and body mass index (BMI). Its association with SDB was assessed by multiple logistic regression analysis. Subgroup analysis and sensitivity analysis were conducted to assess the robustness of our results. The final analysis included 3788 participants (2859 without SDB and 929 with SDB). In multivariable-adjusted analyses, non-smoking (OR: 0.58, 95 % CI: 0.47-0.71), non-drinking (OR: 0.55, 95 % CI: 0.45-0.68), healthy diet (OR: 0.79, 95 % CI: 0.65-0.95), and healthy BMI (OR: 0.72, 95 % CI: 0.6-0.86) were associated with SDB. Compared with participants with HLI score of 0-1, participants with HLI score of 2, 3, 4, and 5 had OR of 0.68 (95 % CI: 0.51-0.91), 0.49 (95 % CI: 0.37-0.64), 0.29 (95 % CI: 0.21-0.38), and 0.22 (95 % CI: 0.15-0.33), respectively, after adjustment for confounding factors (P-trend<0.001). An inverse dose-response relationship between HLI and SDB was also observed. The association was similar in subgroups stratified by sex, marital status, diabetes and dyslipidemia. A higher score of HLI was associated with reduced odds of SDB in Chinese adults. Our findings suggest the potential of addressing five modifiable lifestyle factors for the prevention of SDB.

Could an increased risk of obstructive sleep apnoea be one of the determinants associated with disability in individuals with cardiovascular and cerebrovascular diseases?

PURPOSE

To investigate a possible association between the risk of obstructive sleep apnoea (OSA) and disability in individuals with cardiovascular or cerebrovascular diseases.

METHODS

Cross-sectional study was conducted with 373 individuals (313 with cardiovascular or cerebrovascular diseases and 60 healthy). Disability was assessed by the 12-item World Health Organization Disability Assessment Schedule (WHODAS), and the risk of OSA was assessed by STOP-BANG. Anxiety and depression symptoms, daytime sleepiness, and cognition were assessed by the Hospital Anxiety and Depression Scale (HADS), Epworth Sleepiness Scale (ESS), and Mini Mental State Examination (MMSE).

RESULTS

Greater disability was found in individuals with intermediate or high risk of OSA, considering healthy individuals (p=0.03), or individuals diagnosed with arrhythmia (p<0.01) or coronary artery disease (p=0.04). A high risk of OSA and higher WHODAS scores was significant among women as well as between OSA risk categories (p<0.01). Cognitive deficit and level of education also showed differences between OSA risk categories. Age, depression, and sleepiness were also associated with the subjects' disability (p<0.01). Gamma regression model showed higher WHODAS scores in female, in those with intermediate and high risk of OSA, and in those with depressive symptoms and cognitive deficit. Age also showed a correlation with higher WHODAS scores. The presence of all investigated cardio and cerebrovascular diseases showed an increase in the WHODAS score, implying a greater disability compared to healthy individuals.

CONCLUSION

Moderate and high risk of OSA is associated with disability, as well as gender, age, depressive symptoms, cognitive deficit, and cardiovascular diseases.

Association of Obstructive Sleep Apnea with Post-Acute Sequelae of SARS-CoV-2 Infection

BACKGROUND

Obstructive sleep apnea is associated with COVID-19 infection. Less clear is whether obstructive sleep apnea is a risk factor for the development of post-acute sequelae of SARS-CoV-2 infection (PASC).

STUDY DESIGN

Cross-sectional survey of a general population of 24,803 US adults to determine the association of obstructive sleep apnea with PASC.

RESULTS

COVID-19 infection occurred in 10,324 (41.6%) participants. Prevalence of persistent (>3 months post infection) putative PASC-related physical and mental health symptoms ranged from 6.5% (peripheral edema) to 19.6% (nervous/anxious). In logistic regression models, obstructive sleep apnea was associated with all putative PASC-related symptoms with the highest adjusted odds ratios being fever (2.053) and nervous/anxious (1.939). In 4 logistic regression models of overall PASC derived from elastic net regression, obstructive sleep apnea was associated with PASC (range of adjusted odds ratios: 1.934-2.071); this association was mitigated in those with treated obstructive sleep apnea. In the best fitting overall model requiring ≥3 symptoms, PASC prevalence was 21.9%.

CONCLUSION

In a general population sample, obstructive sleep apnea is associated with the development of PASC-related symptoms and a global definition of PASC. Treated obstructive sleep apnea mitigates the latter risk. The presence of 3 or more PASC symptoms may be useful in identifying cases and for future research.

Sex-dependent effects of chronic intermittent hypoxia: implication for obstructive sleep apnea

BACKGROUND

Obstructive sleep apnea (OSA) affects 10-26% of adults in the United States with known sex differences in prevalence and severity. OSA is characterized by elevated inflammation, oxidative stress (OS), and cognitive dysfunction. However, there is a paucity of data regarding the role of sex in the OSA phenotype. Prior findings suggest women exhibit different OSA phenotypes than men, which could result in under-reported OSA prevalence in women. To examine the relationship between OSA and sex, we used chronic intermittent hypoxia (CIH) to model OSA in rats. We hypothesized that CIH would produce sex-dependent phenotypes of inflammation, OS, and cognitive dysfunction, and these sex differences would be dependent on mitochondrial oxidative stress (mtOS).

METHODS

Adult male and female Sprague Dawley rats were exposed to CIH or normoxia for 14 days to examine the impact of sex on CIH-associated circulating inflammation (IL-1β, IL-6, IL-10, TNF-α), circulating steroid hormones, circulating OS, and behavior (recollective and spatial memory; gross and fine motor function; anxiety-like behaviors; and compulsive behaviors). Rats were implanted with osmotic minipumps containing either a mitochondria-targeting antioxidant (MitoTEMPOL) or saline vehicle 1 week prior to CIH initiation to examine how inhibiting mtOS would affect the CIH phenotype.

RESULTS

Sex-specific differences in CIH-induced inflammation, OS, motor function, and compulsive behavior were observed. In female rats, CIH increased inflammation (plasma IL-6 and IL-6/IL-10 ratio) and impaired fine motor function. Conversely, CIH elevated circulating OS and compulsivity in males. These sex-dependent effects of CIH were blocked by inhibiting mtOS. Interestingly, CIH impaired recollective memory in both sexes but these effects were not mediated by mtOS. No effects of CIH were observed on spatial memory, gross motor function, or anxiety-like behavior, regardless of sex.

CONCLUSIONS

Our results indicate that the impact of CIH is dependent on sex, such as an inflammatory response and OS response in females and males, respectively, that are mediated by mtOS. Interestingly, there was no effect of sex or mtOS in CIH-induced impairment of recollective memory. These results indicate that mtOS is involved in the sex differences observed in CIH, but a different mechanism underlies CIH-induced memory impairments.

Relationship between ODI and sleep structure of obstructive sleep apnea and cardiac remodeling

PURPOSE

The purpose of the study was to evaluate the quantitative relationship between Oxygen Desaturation Index (ODI) and sleep structure of obstructive sleep apnea (OSA) and cardiac remodeling.

METHODS

In this study, patients were enrolled from January 2015 to October 2022, and were divided into 3 groups according to AHI: patients with AHI < 15, patients with 15 ≤ AHI < 30, and 260 patients with AHI ≥ 30. Stratified linear regression was used to analyze independent risk factors for cardiac remodeling in OSA.

RESULTS

A total of 479 patients were enrolled. We found that compared with AHI < 15 group (n = 120), the group with AHI > 30 (n = 260) had increased left atrial anteroposterior diameter, left ventricular end-diastolic internal diameter, left ventricular posterior wall thickness, right ventricular anteroposterior diameter, and interventricular septal thickness (P < 0.05). The group with 15 ≤ AHI ≤ 30 (n = 99) had increased left atrial anteroposterior diameter (P < 0.05). Multivariate linear regression revealed that N2 sleep was an independent risk factor for left ventricular posterior wall thickness, with positive correlation (p < 0.05). N3 sleep was an independent risk factor for transverse right atrial diameter and right ventricular anteroposterior diameter, with negative correlation (P < 0.05). ODI was an independent risk factor for interventricular septal thickness, with positive correlation (P < 0.05). The arousal index was an independent risk factor for increased left atrial anteroposterior diameter, with positive correlation (P < 0.05).

CONCLUSIONS

Increased ODI is an independent risk factor for interventricular septal thickness, while decreased slow wave sleep is an independent risk factor for right heart remodeling in OSA.

Chronic intermittent hypoxia-induced oxidative stress activates TRB3 and phosphorylated JNK to mediate insulin resistance and cell apoptosis in the pancreas

This study explores the potential mechanisms of obstructive sleep apnoea (OSA) complicates type 2 diabetes mellitus (T2DM) by which chronic intermittent hypoxia (CIH) induces insulin resistance and cell apoptosis in the pancreas through oxidative stress. Four- and eight-week CIH rat models were established, and Tempol (100 mg/kg/d), was used as an oxidative stress inhibitor. This study included five groups: 4-week CIH, 4-week CIH-Tempol, 8-week CIH, 8-week CIH-Tempol and normal control (NC) groups. Fasting blood glucose and insulin levels were measured in the serum. The expression levels of 8-hidroxy-2-deoxyguanosine (8-OHdG), tribbles homologue 3 (TRB3), c-Jun N-terminal kinase (JNK), phosphorylated JNK (p-JNK), insulin receptor substrate-1 (IRS-1), phosphorylated IRS-1 (Ser307) (p-IRS-1ser307 ), protein kinase B (AKT), phosphorylated AKT (Ser473) (p-AKTser473 ), B cell lymphoma protein-2 (Bcl-2), cleaved-caspase-3 (Cl-caspase-3), and the islet cell apoptosis were detected in the pancreas. CIH induced oxidative stress in the pancreas. Compared with that in the NC group and CIH-Tempol groups individually, the homeostasis model assessment of insulin resistance (HOMA-IR) and apoptosis of islet cells was increased in the CIH groups. CIH-induced oxidative stress increased the expression of p-IRS-1Ser307 and decreased the expression of p-AKTSer473 . The expression levels of TRB3 and p-JNK were higher in the CIH groups than in both the CIH-Tempol and NC groups. Meanwhile, the expressions of Cl-caspase-3 and Bcl-2 were upregulated and downregulated, respectively, in the CIH groups. Hence, the present study demonstrated that CIH-induced oxidative stress might not only induce insulin resistance but also islet cell apoptosis in the pancreas through TRB3 and p-JNK.

Sex-dependent effects of chronic intermittent hypoxia: Implication for obstructive sleep apnea

Background Obstructive sleep apnea (OSA) affects 10-26% of adults in the United States with known sex differences in prevalence and severity. OSA is characterized by elevated inflammation, oxidative stress (OS), and cognitive dysfunction. However, there is a paucity of data regarding the role of sex in the OSA phenotype. Prior findings suggest women exhibit different OSA phenotypes than men, which could result in under-reported OSA prevalence in women. To examine the relationship between OSA and sex, we used chronic intermittent hypoxia (CIH) to model OSA in rats. We hypothesized that CIH would produce sex-dependent phenotypes of inflammation, OS, and cognitive dysfunction, and these sex differences would be dependent on mitochondrial oxidative stress (mtOS). Methods Adult male and female Sprague Dawley rats were exposed to CIH or normoxia for 14 days to examine the impact of sex on CIH-associated circulating inflammation (IL-1β, IL-4, IL-6, IL-10, TNF-α), circulating OS, and behavior (recollective and spatial memory; gross and fine motor function; anxiety-like behaviors; and compulsive behaviors). A subset of rats was implanted with osmotic minipumps containing either a mitochondria-targeting antioxidant (MitoTEMPOL) or saline vehicle 1 week prior to CIH initiation to examine how inhibiting mtOS would affect the CIH phenotype. Results Sex-specific differences in CIH-induced inflammation, OS, motor function, and compulsive behavior were observed. In female rats, CIH increased inflammation (plasma IL-6 and IL-6/IL-10 ratio) and impaired fine motor function. Conversely, CIH elevated circulating OS and compulsivity in males. These sex-dependent effects of CIH were blocked by inhibiting mtOS. Interestingly, CIH impaired recollective memory in both sexes but these effects were not mediated by mtOS. No effects of CIH were observed on spatial memory, gross motor function, or anxiety-like behavior, regardless of sex. Conclusions Our results indicate that the impact of CIH is dependent on sex, such as an inflammatory response and OS response in females and males, respectively, that are mediated by mtOS. Interestingly, there was no effect of sex or mtOS in CIH-induced impairment of recollective memory. These results indicate that mtOS is involved in the sex differences observed in CIH, but a different mechanism underlies CIH-induced memory impairments.

Gestational intermittent hypoxia induces endothelial dysfunction and hypertension in pregnant rats: role of endothelin type B receptor†

Obstructive sleep apnea is a recognized risk factor for gestational hypertension, yet the exact mechanism behind this association remains unclear. Here, we tested the hypothesis that intermittent hypoxia, a hallmark of obstructive sleep apnea, induces gestational hypertension through perturbed endothelin-1 signaling. Pregnant Sprague-Dawley rats were subjected to normoxia (control), mild intermittent hypoxia (10.5% O2), or severe intermittent hypoxia (6.5% O2) from gestational days 10-21. Blood pressure was monitored. Plasma was collected and mesenteric arteries were isolated for myograph and protein analyses. The mild and severe intermittent hypoxia groups demonstrated elevated blood pressure, reduced plasma nitrate/nitrite, and unchanged endothelin-1 levels compared to the control group. Western blot analysis revealed decreased expression of endothelin type B receptor and phosphorylated endothelial nitric oxide synthase, while the levels of endothelin type A receptor and total endothelial nitric oxide synthase remained unchanged following intermittent hypoxia exposure. The contractile responses to potassium chloride, phenylephrine, and endothelin-1 were unaffected in endothelium-denuded arteries from mild and severe intermittent hypoxia rats. However, mild and severe intermittent hypoxia rats exhibited impaired endothelium-dependent vasorelaxation responses to endothelin type B receptor agonist IRL-1620 and acetylcholine compared to controls. Endothelium denudation abolished IRL-1620-induced vasorelaxation, supporting the involvement of endothelium in endothelin type B receptor-mediated relaxation. Treatment with IRL-1620 during intermittent hypoxia exposure significantly attenuated intermittent hypoxia-induced hypertension in pregnant rats. This was associated with elevated circulating nitrate/nitrite levels, enhanced endothelin type B receptor expression, increased endothelial nitric oxide synthase activation, and improved vasodilation responses. Our data suggested that intermittent hypoxia exposure during gestation increases blood pressure in pregnant rats by suppressing endothelin type B receptor-mediated signaling, providing a molecular mechanism linking intermittent hypoxia and gestational hypertension.

Gut microbiota and metabolic profiles in chronic intermittent hypoxia-induced rats: disease-associated dysbiosis and metabolic disturbances

Aim

Chronic intermittent hypoxia (CIH) is a key characteristic of obstructive sleep apnea (OSA) syndrome, a chronic respiratory disorder. The mechanisms of CIH-induced metabolic disturbance and histopathological damage remain unclear.

Methods

CIH-induced rats underwent daily 8-h CIH, characterized by oxygen levels decreasing from 21% to 8.5% over 4 min, remaining for 2 min, and quickly returning to 21% for 1 min. The control rats received a continuous 21% oxygen supply. The levels of hypersensitive C reactive protein (h-CRP), tumor necrosis factor-α (TNF-α), interleukin 6 (IL-6), interleukin 8 (IL-8), and nuclear factor kappa-B (NF-κB) were measured by ELISA. Histological analysis of the soft palates was conducted using HE staining. The microbial profiling of fecal samples was carried out by Accu16STM assay. Untargeted metabolomics of serum and soft palate tissue samples were analyzed by UPLC-MS. The protein expression of cAMP-related pathways in the soft palate was determined by Western blot.

Results

After 28 h of CIH induction, a significant increase in pro-inflammatory cytokines was observed in the serum, along with mucosal layer thickening and soft palate tissue hypertrophy. CIH induction altered the diversity and composition of fecal microbiota, specifically reducing beneficial bacteria while increasing harmful bacteria/opportunistic pathogens. Notably, CIH induction led to a significant enrichment of genera such as Dorea, Oscillibacter, Enteractinococcus, Paenibacillus, Globicatella, and Flaviflexus genera. Meanwhile, Additionally, CIH induction had a notable impact on 108 serum marker metabolites. These marker metabolites, primarily involving amino acids, organic acids, and a limited number of flavonoids or sterols, were associated with protein transport, digestion and absorption, amino acid synthesis and metabolism, as well as cancer development. Furthermore, these differential serum metabolites significantly affected 175 differential metabolites in soft palate tissue, mainly related to cancer development, signaling pathways, amino acid metabolism, nucleotide precursor or intermediate metabolism, respiratory processes, and disease. Importantly, CIH induction could significantly affect the expression of the cAMP pathway in soft palate tissue.

Conclusions

Our findings suggest that targeting differential metabolites in serum and soft palate tissue may represent a new approach to clinical intervention and treatment of OSA simulated by the CIH.

Association of Obstructive Sleep Apnea with Post-Acute Sequelae of SARS-CoV-2 infection (PASC)

Background

Obstructive sleep apnea (OSA) is associated with COVID-19 infection. Fewer investigations have assessed OSA as a possible risk for the development of Post-Acute Sequelae of SARS-CoV-2 infection (PASC).

Research Question

In a general population, is OSA associated with increased odds of PASC-related symptoms and with an overall definition of PASC?

Study Design

Cross-sectional survey of a general population of 24,803 U.S. adults.

Results

COVID-19 infection occurred in 10,324 (41.6%) participants. Prevalence rates for a wide variety of persistent (> 3 months post infection) putative PASC-related physical and mental health symptoms ranged from 6.5% (peripheral edema) to 19.6% (nervous/anxious). In logistic regression models adjusted for demographic, anthropometric, comorbid medical and socioeconomic factors, OSA was associated with all putative PASC-related symptoms with the highest adjusted odds ratios (aOR) being fever (2.053) and nervous/anxious (1.939) respectively. Elastic net regression identified the 13 of 37 symptoms most strongly associated with COVID-19 infection. Four definitions of PASC were developed using these symptoms either weighted equally or proportionally by their regression coefficients. In all 4 logistic regression models using these definitions, OSA was associated with PASC (range of aORs: 1.934-2.071); this association was mitigated in those with treated OSA. In the best fitting overall model requiring ≥3 symptoms, PASC prevalence was 21.9%.

Conclusion

In a general population sample, OSA is associated with the development of PASC-related symptoms and a global definition of PASC. A PASC definition requiring the presence of 3 or more symptoms may be useful in identifying cases and for future research.

Possible genetic cross-talk between Down syndrome and obstructive sleep apnea revealed by transcriptomic analysis

PURPOSE

Down syndrome (DS) is linked to a higher prevalence of obstructive sleep apnea (OSA) than in the general population, which in turn contributes to worse cognitive impairment in DS. However, the shared pathogenic mechanisms for DS and OSA remain incompletely illustrated. This study was designed to decipher the genetic cross-talk between DS and OSA by bioinformatics approach.

METHODS

Transcriptomic datasets of DS (GSE59630) and OSA (GSE135917) were accessed from the Gene Expression Omnibus (GEO) repository. After screening out the common differentially expressed genes (DEGs) for DS and OSA, gene ontology (GO) functional enrichment analysis and Kyoto Encyclopedia of Genes and Genomes (KEGG) pathway analysis were carried out. A protein-protein interaction (PPI) network was then constructed to determine essential modules and hub genes. Finally, based on hub genes, transcriptional factor (TF)-gene interaction and TF-miRNA regulatory networks were constructed.

RESULTS

DS and OSA showed 229 DEGs. Functional analyses revealed how oxidative stress and inflammatory response were critical in the progression of DS and OSA. Ten significant hub genes were identified, including TLR4, SOD1, IGF1, FGF2, NFE2L2, PECAM1, S100A8, S100A9, FCGR3A, and KCNA1, which were candidate targets for DS and OSA.

CONCLUSIONS

We found that DS and OSA display similarities in their pathogenesis. Key genes and signaling pathways revealed to be in common between the two conditions could lead us to new therapeutic targets for DS and OSA.

Association between snoring, daytime sleepiness and cardiovascular disease in Chinese rural adults

BACKGROUNDS AND AIMS

Evidence on the association between habitual snoring, excessive daytime sleepiness (EDS), and cardiovascular diseases (CVDs) remains uncertain and limited. The study aimed to explore the independent and joint association between habitual snoring, EDS, and CVDs in rural Chinese adults.

METHODS AND RESULTS

A total of 28,140 participants from the Henan rural cohort study were included. Sleep status information was obtained by self-reported. Based on their sleep status, the participants were classified into four groups: "no snoring and no EDS (NSNS) (reference group)", "snoring and no EDS (SNS)", "no snoring and EDS (NSS)", "snoring and EDS (SS)." The logistic regression models were used to calculate independent and joint odds ratios (OR) and 95% confidence intervals (CI) between the snoring, EDS status and stroke, CHD, and CVD. Of the 28,140 participants, 740 subjects reported snoring and sleepiness. The ORs and (95% CIs) for CVDs in the adjusted model were 1.31 (1.20-1.43) for participants who snored frequently and 2.44 (1.76-3.39) for frequent sleepiness compared with no snoring and no sleepiness. Individuals with both snoring and sleepiness had higher odds of CVDs compared with no snoring and no sleepiness (OR: 2.18, 95%CI: 1.80-2.62).

CONCLUSION

Habitual snoring and excessive daytime sleepiness were independently and jointly associated with CVDs in the Chinese rural population. More studies are needed to explore the mechanisms of the relationship.

CLINICAL TRIAL REGISTRATION

The Henan Rural Cohort Study has been registered at the Chinese Clinical Trial Register (Registration number: ChiCTR-OOC-15006699). Date of registration: 2015-52 07-06. http://www.chictr.org.cn/showproj.aspx?proj=11375.

Association between multiple metals exposure and sleep disorders in a Chinese population: A mixture-based approach

OBJECTIVE

Previous studies have suggested a possible association between metals and sleep disorders. This study aimed to explore the association between Zn, Cu, Se, Mg and Ca and sleep disorders in single and multi-metal co-exposure models.

METHODS

Logistic regression models, restricted cubic spline model (RCS), Quantile g computation (Q-gcomp), Weighted Quantile Sum (WQS), and Bayesian kernel machine regression (BKMR) models were used to investigate the association between metal levels and sleep disorders.

RESULTS

Logistic regression showed that in the total population, the second, third, and fourth quartile Zn concentration exhibited a lower risk of sleep disorders compared with the first quartile, with odds ratios (ORs) of 0.783, 0.711, and 0.704, respectively. Compared with Zn/Cu and Zn/Se in the first quartile, the third and fourth quartiles showed a lower risk of sleep disorders. In the 30-59 years group, the risk of sleep disorders was 0.699 times greater for the fourth quartile Mg concentration than that for the first quartile. The risk of sleep disorders in Mg/Ca concentration in the third quartile was 0.737 times higher than in the first quartile. Q-gcomp, WQS, and BKMR model analysis showed the negative overall effect of mixtures of the five metals on sleep disorders, with Zn being the largest contributor.

CONCLUSION

Our study showed that plasma Zn, Mg, Zn/Cu, Zn/Se, and Mg/Ca reduced the risk of sleep disorders, and the combined effect of multiple metals was negatively associated with the risk of sleep disorders, with Zn being the largest contributor to this relationship.

Meta-analysis of the effects of CPAP therapy on estimated glomerular filtration rate in patients with obstructive sleep apnea

PURPOSE

Obstructive sleep apnea (OSA) is highly prevalent in patients with chronic kidney disease and may lead to a loss of kidney function. However, it remains unclear whether or not continuous positive airway pressure (CPAP) treatment improves the estimated glomerular filtration rate (eGFR) in patients with OSA. This meta-analysis was designed to investigate the effect of CPAP therapy on eGFR in patients with OSA.

METHODS

We searched the electronic databases Web of Science, Cochrane Library, PubMed, and Embase through June 1, 2022. Information about patients, CPAP duration, gender distribution, pre- and post-CPAP treatment eGFR, and age of patients were collected for further analysis. We applied the standardized mean difference (SMD) with a 95%confidence interval (CI) to analyze the pooled effects. Both Stata 12.0 software and Review Manager 5.2 software were employed for all statistical analyses.

RESULTS

A sample of 13 studies with 519 patients was included in the meta-analysis. There was no significant change of eGFR levels before and after CPAP usage for patients with OSA (SMD =  - 0.05, 95%CI: - 0.30 to 0.19, Z = 0.43, p = 0.67). However, subgroup analysis revealed that the level of eGFR was obviously decreased after CPAP therapy in patients with OSA and CPAP use duration > 6 months (SMD =  - 0.30, 95% CI =  - 0.49 to - 0.12, z = 3.20, p = 0.001), and elderly patients (> 60 years) (SMD =  - 0.32, 95% CI =  - 0.52 to - 0.11, z = 3.02, p = 0.002).

CONCLUSIONS

Meta-analysis confirmed that OSA treatment with CPAP has no clinically significant effect on eGFR.

Differential Modulation of Markers of Oxidative Stress and DNA Damage in Arterial Hypertension

Patients with arterial hypertension have an increased risk of developing tumors, particularly renal cell carcinoma. Arterial hypertension is linked to DNA damage via the generation of oxidative stress, in which an upregulated renin-angiotensin-aldosterone system plays a crucial role. The current study investigated surrogates of oxidative stress and DNA damage in a group of hypertensive patients (HypAll, n = 64) and subgroups of well (HypWell, n = 36) and poorly (HypPoor, n = 28) controlled hypertensive patients compared to healthy controls (n = 8). In addition, a longitudinal analysis was performed with some of the hypertensive patients. Markers for oxidative stress in plasma (SHp, D-ROM, and 3-nitrotyrosine) and urine (8-oxodG, 15-F2t-isoprostane, and malondialdehyde) and markers for DNA damage in lymphocytes (γ-H2AX and micronuclei) were measured. In HypAll, all markers of oxidative stress except malondialdehyde were increased compared to the controls. After adjustment for age, this association was maintained for the protein stress markers SHp and 3-nitrotyrosine. With regard to the markers for DNA damage, there was no difference between HypAll and the controls. Further, no significant differences became apparent in the levels of both oxidative stress and DNA damage between HypWell and HypPoor. Finally, a positive correlation between the development of blood pressure and oxidative stress was observed in the longitudinal study based on the changes in D-ROM and systolic blood pressure. In conclusion, we found increased oxidative stress in extensively treated hypertensive patients correlating with the level of blood-pressure control but no association with DNA damage.

Associations between insomnia and large vessel occlusion acute ischemic stroke: An observational study

OBJECTIVES

This study explored the association between insomnia and the clinical outcome of large vessel occlusion Acute Ischemic Stroke (AIS) and attempted to explore its potential mechanisms from the perspectives of inflammation and oxidative stress.

METHODS

AIS patients who underwent endovascular treatment for large vessel occlusion at Binzhou Central Hospital from 2018 to 2022 (n = 508) were included. Patients were divided into an insomnia group and a non-insomnia group. Insomnia was judged by self-reported Athens Insomnia Scale score. Regression analysis was used to compare the differences in the 24-hour and 7-day National Institutes of Health Stroke Scale (NIHSS) score, Early Neurological Deterioration (END), early adverse event incidence, 90-day prognosis and mortality, and serum biomarkers levels.

RESULTS

The incidence of insomnia in the study population was 39.6% (n = 144, insomnia group; n = 364, non-insomnia group). Compared with the non-insomnia group, a worse prognosis outcome (63% vs. 49%, adjusted rate ratio: 1.8, 95% Confidence Interval: 1.2-3.7; p = 0.016), higher 24-h and 7-day NIHSS score (17 [9-36] vs. 13 [5-20]; p = 0.024, and 11 [4‒24) vs. 8 [2‒14]; p = 0.031, respectively), higher END (24% vs. 15%, p = 0.022), and higher incidence of adverse events were observed in the insomnia group (79% vs. 59%, p = 0.010). The 90-day mortality was higher in the insomnia group than that in the non-insomnia group (22% vs. 17%), however, such a difference was not statistically significant.

CONCLUSION

Insomnia is closely related to the clinical outcome of AIS with large vessel occlusion, and inflammation and oxidative stress mechanisms may be involved.

Implications of sleep disorders for periodontitis

PURPOSE

Periodontitis is a chronic inflammatory disease caused by multi-factors. Sleep is a natural physiologic process, and the sleep duration, quality, and patterns might be associated with periodontitis. Meanwhile, periodontitis might in turn induce systemic inflammation and thus impact sleep in different ways as well.

METHODS

To investigate the bidirectional relationship between sleep disorder and periodontitis, a literature search was conducted to reveal the interaction and possible mechanism between these two diseases.

RESULTS

The results show that sleep disorders can affect the progression of periodontitis via some pathomechanisms, and periodontitis also has a reverse impact on sleep.

CONCLUSION

Although the epidemiologic and clinical trials found the possible associations between sleep disorder and periodontitis, their relationship is still not that explicit. Further studies are warranted to shed light on them, to improve preventive health care.

A Relation between Obstructive Sleep Apnea in Pregnancy and Delivering Small for Gestational Age Infant-A Systematic Review

Obstructive sleep apnea (OSA) during pregnancy can negatively affect both the mother and the baby. Our main goal is to show whether there is an association between OSA during pregnancy and delivering small for gestational age (SGA) infants. This systematic review was conducted according to the PRISMA 2020 statement using three databases: MEDLINE via PubMed, Scopus, and Cochrane Library. All databases were last accessed on 1 June 2023. The implemented systematic literature search identified 744 articles. After excluding reviews, meta-analyses, book chapters, case reports, and letters, 47 studies were analyzed, 18 of which finally met the inclusion criteria. The included studies mainly indicate that OSA during pregnancy may not significantly impact SGA, but some of them have shown the existence of this relation. Nevertheless, it is recommended that all pregnant women should be screened for symptoms of OSA and that sleep tests should be performed on those who show signs of it. Detecting and treating OSA early in pregnancy can help reduce the condition's negative effects. However, more extensive studies are still needed to gather clear evidence on the impact of an OSA diagnosis on mothers and babies.

Association between Obstructive Sleep Apnea and Intracranial Artery Calcification Stratified by Gender and Body Mass Index: A Hospital-Based Observational Study

BACKGROUND AND OBJECTIVES

Obstructive sleep apnea (OSA) is an independent risk factor for stroke. Furthermore, intracranial arterial calcification (IAC) has been validated as a marker for subclinical cerebrovascular disease. However, the relationship between OSA with IAC was less studied compared with its established association with coronary artery calcification. In this study, we aimed to investigate the association between the severity of OSA and the degree of IAC in hospitalized patients without preexisting cardiovascular disease.

METHODS

This hospital-based observational study was conducted from June 1, 2017, to May 1, 2019. In total, 901 consecutive patients who underwent head computed tomography scans and portable sleep monitoring were included. On the basis of the apnea-hypopnea index (AHI), patients were divided into four OSA severity groups (normal: AHI <5/h; mild: 5≤ AHI <15/h; moderate: 15≤ AHI <30/h; severe: AHI ≥30/h). Associations of OSA with IAC scores were assessed by using multivariate logistic regression analysis.

RESULTS

Of the 901 patients, 484 (53.7%) were men; the mean (SD) age was 66.1 (10.0) years. The non-OSA group included 207 (23.0%) patients; mild OSA, 209 (23.2%); moderate OSA, 235 (26.1%); and severe OSA, 169 (18.8%). Mean IAC scores were higher in the severe OSA group compared with non-, mild, and moderate OSA groups (4.79 vs. 2.58; 4.79 vs. 2.94; 4.79 vs. 3.39; p < 0.001). Multivariate analysis adjusted for confounding factors revealed that only severe OSA was associated with a higher IAC score (odds ratio [OR]: 1.65; 95% confidence interval [CI]: 1.43-1.91; p < 0.001). In stratified analyses by BMI, among participants with a BMI <25 kg/m2, the positive association between AHI values and IAC scores was found in the moderate OSA group (OR: 1.23; 95% CI: 1.05, 1.43; p = 0.01) and the severe OSA group (OR: 1.96; 95% CI: 1.55, 2.48; p < 0.001). When stratified by gender, in women, the positive association was found in the moderate OSA group (adjusted OR: 1.21; 95% CI: 1.02-1.51; p = 0.016) and the severe OSA group (adjusted OR: 1.76; 95% CI: 1.36-2.25; p < 0.001). For the men group, a positive association between IAC scores and AHI was only observed in the severe OSA group.

DISCUSSION

These findings suggest that OSA, in particular severe OSA (AHI ≥30), is independently associated with higher IAC scores. Women and no-obesity individuals appeared more susceptible to adverse OSA-related subclinical cerebrovascular disease as measured by IAC scores.

The effect of continuous positive airway pressure on total antioxidant capacity in obstructive sleep apnea: a systematic review and meta-analysis

BACKGROUND

Obstructive sleep apnea (OSA), a sleep-related disorder with high prevalence, is associated with an imbalance in oxidative stress and is linked to cardiovascular disease. There are conflicting reports regarding the effectiveness of continuous positive airway pressure (CPAP) therapy on oxidative stress/antioxidant markers in patients with OSA. This review was performed to evaluate the influence of therapy with CPAP on serum/plasma total antioxidant capacity (TAC) in patients with OSA.

METHODS

The Cochrane Library, Web of Science, Scopus, Embase, and PubMed were searched through June 2022 to obtain studies evaluating CPAP treatment on TAC in patients with OSA. Overall results were tested using standardized mean difference (SMD) with a 95% confidence interval (CI). Comprehensive Meta-Analysis V2 software was employed to perform analyses.

RESULTS

Ten studies with 12 effect sizes were eligible for inclusion in this analysis. The overall SMD revealed that CPAP therapy significantly increased TAC [SMD 0.497; 95% CI: 0.21 to 0.77; p: 0.00] in OSA. Analyses based on subgroups showed that the effect of CPAP therapy was significant in all subgroups according to therapy duration, age, BMI, and AHI. Whereas the meta-regression results indicated that the impact of therapy with CPAP on TAC is associated with AHI, BMI, and age in patients with OSA.

CONCLUSIONS

The finding of this meta-analysis demonstrated a favorable impact of CPAP therapy on TAC levels in patients suffering from OSA.

Inflammatory biomarkers of neutrophil-to-lymphocyte and platelet-to-lymphocyte ratios in 563 severe OSA patients before and after surgery

BACKGROUND

Evidence has proved that high neutrophil-to-lymphocyte ratio (NLR) and platelet-to-lymphocyte ratio (PLR) were risk factors for cardiovascular comorbidities. The alterations of NLR and PLR following obstructive sleep apnea (OSA) treatment were under studied and thus should be investigated. This study aimed to evaluate the changes of inflammatory biomarkers including NLR and PLR in severe OSA patients after surgical interventions of the upper airway, and their relationships with improvements in polysomnographic (PSG) parameters.

METHODS

This retrospective cohort study included 563 consecutive severe OSA patients at a tertiary academic medical center who received OSA surgery, as well as underwent pre- and post-operative polysomnographic (PSG) examinations and blood tests. The changes of major PSG estimates, NLR, and PLR before and at least 3 months after OSA surgery were analyzed using paired t-tests with subgroup analyses. Pearson's correlations were performed to discover which PSG parameter contributed to the improvement of the values.

RESULTS

After OSA surgery, the major PSG estimates, NLR and PLR dropped significantly in the overall population. In those with a higher preoperative NLR (pre-operative NLR≧3) and PLR (pre-operative PLR≧150), the mean (SD) difference of NLR (- 0.8 [1.6], 95% CI - 1.5 to - 0.2) and PLR (- 41.6 [40], 95% CI - 52.8 to - 30.5) were even more substantial. The changes of the "apnea, longest (r = 0.298, P = .037)" and "hypopnea, longest (r = 0.321, P = .026)" were found significantly related to the improvement of PLR.

CONCLUSION

NLR and PLR did significantly drop in severe OSA patients following OSA surgery, and this could be related to the alterations of sleep indices. The findings could possess clinical importance for severe OSA patients after OSA surgeries in reducing possible OSA-associated cardiovascular comorbidities.

Association between mean platelet volume and cardiovascular disease in obstructive sleep apnea syndrome

Objectives

Obstructive sleep apnea syndrome is associated with cardiovascular diseases. Mean platelet volume has emerged as a marker of prothrombotic conditions and cardiovascular risk. The aim of this study was to investigate the association between the mean platelet volume and cardiovascular diseases in patients with obstructive sleep apnea syndrome.

Methods

The medical records of 207 patients were analyzed. Obstructive sleep apnea syndrome was diagnosed by polygraphy, and patients were classified according to apnea-hypopnea index: control group: individuals with simple snoring (apnea-hypopnea index < 5), mild obstructive sleep apnea syndrome group (5 ⩽ apnea-hypopnea index < 15), moderate obstructive sleep apnea syndrome group (15 ⩽ apnea-hypopnea index < 30), and severe obstructive sleep apnea syndrome group (apnea-hypopnea index ⩾ 30). Mean platelet volume was obtained from medical records. Cardiovascular diseases were defined if patients had hypertension, heart failure, coronary artery disease, or arrythmia. The independent predictors related to cardiovascular diseases in obstructive sleep apnea syndrome were determined by using multiple logistic regression analysis.

Results

Of the patients, 175 were included in the analysis. Sixty-three (36%) were males and 112 (64%) were females. The mean age was 51.85 ± 11 years. There were, 26 (14.9%), 53 (30.3%), 38 (21.7%), and 58 (33.1%) participants in the simple snoring, mild, moderate, and severe obstructive sleep apnea syndrome groups, respectively. Cardiovascular diseases were significantly different between the four groups (p = 0.014). Mean platelet volume in severe obstructive sleep apnea syndrome group was significantly higher than in mild or moderate obstructive sleep apnea syndrome group and simple snoring group (p < 0.05). Moreover, there was a positive correlation between mean platelet volume levels and apnea-hypopnea index (r = 0.424; p < 0.001). The independent predictors of cardiovascular diseases in obstructive sleep apnea syndrome were age (p < 0.001; odds ratio = 1.134; confidence interval: 1.072-1.2), body mass index (p = 0.012; odds ratio: 1.105; confidence interval: 1.022-1.194), and mean platelet volume (p < 0.001; odds ratio: 2.092; confidence interval: 1.386-3.158).

Conclusion

The present study demonstrated that there is an association between mean platelet volume levels and cardiovascular diseases in patients with obstructive sleep apnea syndrome.

Modulation of NRF2/KEAP1 Signaling in Preeclampsia

Placentation is a key and tightly regulated process that ensures the normal development of the placenta and fetal growth. Preeclampsia (PE) is a hypertensive pregnancy-related disorder involving about 5-8% of all pregnancies and clinically characterized by de novo maternal hypertension and proteinuria. In addition, PE pregnancies are also characterized by increased oxidative stress and inflammation. The NRF2/KEAP1 signaling pathway plays an important role in protecting cells against oxidative damage due to increased reactive oxygen species (ROS) levels. ROS activate NRF2, allowing its binding to the antioxidant response element (ARE) region present in the promoter of several antioxidant genes such as heme oxygenase, catalase, glutathione peroxidase and superoxide dismutase that neutralize ROS, protecting cells against oxidative stress damages. In this review, we analyze the current literature regarding the role of the NRF2/KEAP1 pathway in preeclamptic pregnancies, discussing the main cellular modulators of this pathway. Moreover, we also discuss the main natural and synthetic compounds that can regulate this pathway in in vivo and in vitro models.

Comparison of ocular surface assessment outcomes between healthy controls and patients with obstructive sleep apnea-hypopnea syndrome: a meta-analysis of the literature

Objective: This meta-analysis aims to determine whether ocular surface alterations are associated with disease severity in patients with obstructive sleep apnea-hypopnea syndrome (OSAHS). Methods: The protocol for this systematic review and meta-analysis was registered in PROSPERO. We conducted the search in six electronic databases (China National Knowledge Infrastructure, EMBASE, Cochrane Library, Web of Science, Wanfang, and PubMed) from since the construction of the databases to 30 December 2022. The standard mean difference (SMD) and correlation coefficients are reported as measures of the effect size in the presence of retrieved data. In addition, the random effects model or fixed effects model was used in a combined analysis. Stata 11.0 and R 3.6.1 were used for statistical analyses of the data. Results: A total of 15 studies satisfied the inclusion criteria for this study. The prevalence of floppy eyelid syndrome (FES) and dry eye syndrome in patients with obstructive sleep apnea-hypopnea syndrome was 40 and 48%, respectively. In addition, the Schirmer 1 value and tear break-up time (TBUT) were remarkably reduced in patients with OSAHS when compared to that of the controls. The ocular surface disease index (OSDI) scores, Oxford corneal staining scores, and the rates of loss in the meibomian glands were elevated in patients with obstructive sleep apnea-hypopnea syndrome when compared to that of the controls, especially those with severe disease. Moreover, the Schirmer 1 value and tear break-up time exhibited a negative correlation with the apnea-hypopnea index (AHI), and the OSDI showed a positive association with the apnea-hypopnea index. Conclusion: Patients with OSAHS had a greater prevalence of FES than the healthy controls. They also showed lower Schirmer 1 value and tear break-up time but had a higher OSDI, Oxford corneal staining scores, and rates of loss in the meibomian glands than the healthy controls. Clinical Trial Registration: (https://www.crd.york.ac.uk/prospero/display_record.php?RecordID=392527).

The Influence of Dietary Interventions on Arterial Stiffness in Overweight and Obese Subjects

Arterial stiffness is often increased in overweight/obese subjects before the development of hypertension. It is also one of the earliest indicators of increased cardiovascular disease risk and can be considered a good predictor of the development of subclinical cardiovascular dysfunction. Arterial stiffness is a significant prognostic factor influencing cardiovascular risk, which dietary habits can modify. Obese patients should use the caloric-restricted diet because it augments aortic distensibility, diminishes pulse wave velocity (PWV), and increases the activity of endothelial nitric oxide synthases. High intake of saturated fatty acids (SFA), trans fats, and cholesterol, typical for the Western diet, impairs endothelial function and raises brachial-ankle PMV. The replacement of SFA with monounsaturated (MUFA) or polyunsaturated fatty acids (PUFA) derived from seafood and plants diminishes the risk of arterial stiffness. The dairy product intake (excluding butter) decreases PWV in the general population. The high-sucrose diet causes toxic hyperglycemia and increases arterial stiffness. Complex carbohydrates with a low glycemic index (including isomaltose) should be recommended to keep vascular health. The high sodium intake (>10 g/day), particularly associated with low potassium consumption, has a deleterious effect on arterial stiffness (↑ baPWV). Since vegetables and fruits are good sources of vitamins and phytochemicals, they should be recommended in patients with high PMV. Thus, the dietary recommendation to prevent arterial stiffness should be similar to the Mediterranean diet, which is rich in dairy products, plant oils, and fish, with a minimal red meat intake and five servings of fruits and vegetables daily.

[Current Status of and Progress in Research on Obstructive Sleep Apnea and Comorbid Depressive Disorders]

Obstructive sleep apnea (OSA) and depressive disorders are common diseases in adults and they share in common many clinical symptoms, including sleep disturbance, fatigue, lack of concentration and cognitive function impairment. OSA and depressive disorders also share some common pathophysiological changes, including increased activity of the hypothalamic-pituitary-adrenal (HPA) axis, chronic low-grade inflammation, oxidative stress, and changes in gut microbiota and neurotransmitters, which may contribute to the comorbidity of OSA and depressive disorders. In the case of comorbid OSA and depressive disorders, OSA and depressive disorders may affect and exacerbate each other, thereby increasing the severity of diseases, entailing greater risk of cardiovascular and metabolic diseases, and causing greater difficulty in treatment. Herein, we summarized the latest research findings on the epidemiology, possible mechanisms, harms, and treatment of comorbid OSA and depressive disorders. This review may help improve clinicians' understanding of the comorbidity of OSA and depression disorders, thereby promoting early screening, prompt diagnosis and treatment, and improved prognosis. Further studies are needed for better understanding of the effect of the comorbidity of OSA and depressive disorders and treatment on cardiometabolic diseases.

Lipoprotein Subfractions Associated with Endothelial Function in Previously Healthy Subjects with Newly Diagnosed Sleep Apnea-A Pilot Study

BACKGROUND

Obstructive sleep apnea (OSA) activates several pathophysiological mechanisms which can lead to the development of vascular diseases. Endothelial dysfunction (ED) is an initial step in the development of atherosclerosis. The association between ED and OSA has been described in several studies, even in previously healthy subjects. High-density lipoproteins (HDL) were generally considered to be atheroprotective, and low-density lipoprotein (LDL) to be an atherogenic component of lipoproteins. However, recent findings suggest a pro-atherogenic role of small HDL subfractions (8-10) and LDL subfractions (3-7). This study aimed to evaluate the relationship between endothelial function and lipid subfractions in previously healthy OSA subjects.

MATERIAL AND METHODS

We prospectively enrolled 205 subjects with sleep monitoring. Plasma levels of triacylglycerols, total cholesterol, LDL, HDL, and their subfractions were assessed. Endothelial function was determined using peripheral arterial tonometry, and reperfusion hyperemia index (RHI) was assessed.

RESULTS

Plasma levels of small and intermediate HDL subfractions have statistically significant pro-atherogenic correlations with endothelial function (p = 0.015 and p = 0.019). In other lipoprotein levels, no other significant correlation was found with RHI. In stepwise multiple linear regression analysis, small HDL (beta = -0.507, p = 0.032) was the only significant contributor in the model predicting RHI.

CONCLUSIONS

In our studied sample, a pro-atherogenic role of small HDL subfractions in previously healthy subjects with moderate-to-severe OSA was proven.

Mechanism of Aspirin oxidative stress regulating interleukin-induced apoptosis in nucleus pulposus cells in a rat model of intervertebral disc degeneration

Background

Intervertebral disc degeneration (IDD) is an important cause of low back pain. Increase of reactive oxygen species (ROS), overexpression of inflammatory factors, and loss of extracellular matrix are important factors in the pathological changes of IDD. The present study aimed to investigate the mechanism of action of Aspirin regulating oxidative stress in IDD, so as to propose new treatment.

Methods

Nucleus pulposus cells (NPCs) were isolated from the caudal intervertebral discs of Sprague Dawley (SD) rats under sterile conditions. The expression of ROS and inflammatory factors was detected sequentially, and the degree of degeneration of nucleus pulposus cells was observed by real-time fluorescence quantitative polymerase chain reaction (PCR) and cell immunofluorescence staining. In vivo, the caudal disc puncture model was used to induce degeneration, and a local injection of 10 or 100 µg/mL Aspirin was performed. The rats were sacrificed 1 week later, and the disc specimens of the tail vertebrae were collected for imaging, histomorphology, and immunohistochemical analysis.

Results

In vitro experiments showed that lipopolysaccharide (LPS) could significantly induce oxidative stress in NPCs and stimulate NPCs to secrete a large amount of ROS and inflammatory factors, which eventually leads to the reduction of collagen type II and polyglycoprotein gene expression in NPCs and the high expression of matrix metalloproteinase (MMP). Consequently, NPCs degeneration occurs.

Conclusions

Our results clarified the important role of oxidative stress in IDD and proved that LPS can be used as a drug to alleviate oxidative stress and intervene in the IDD process.

Association between Selenium Intake and Optimal Sleep Duration: A National Longitudinal Study

Inconsistent findings have been discovered in studies examining the link between dietary selenium (Se) and sleep. Data were obtained from 17,176 people aged 20 and over who participated in the China Health and Nutrition Survey (CHNS) from 2004 to 2011. Face-to-face interviews were used to measure sleep duration in 2004, 2006, 2009, and 2011. To track dietary Se consumption, a 3-day, 24-h recall was undertaken. In the analysis, multilevel mixed-effects logistic regression was employed. The odds ratios (95% confidence intervals) of optimal sleep duration (7-9 h/day) in the regression of Model 4 were 1.00, 1.01 (0.89-1.15) and 1.19 (1.02-1.38) for the three tertiles of selenium consumption, respectively. Only overweight patients displayed a substantial positive connection between Se intake and the optimal sleep duration in the subgroup analysis. In summary, Se intake was significantly associated with optimal sleep duration.

Obstructive Sleep Apnea and Risk of Miscarriage

The purpose of this project was to evaluate whether screening positive on obstructive sleep apnea questionnaires in the first trimester of pregnancy was associated with miscarriage. This was a secondary analysis of a prospective observational cohort study of participants who were screened for sleep apnea during pregnancy with the Epworth Sleepiness Scale, Berlin Questionnaire, and novel items related to sleep and napping. This secondary analysis was IRB exempt. Our primary outcome was miscarriage in the index pregnancy. An association between responses to the sleep apnea screening questions with miscarriage of the index pregnancy was queried via Poisson regression. We found that gravidae who had elevated scores on both the Epworth Sleepiness Scale and the Berlin Questionnaire were more likely to experience miscarriage than those who had elevated scores on only one questionnaire or neither (p = 0.018). Gravidae who reported snoring (p = 0.042) or hypertension (p = 0.013) in the first trimester were more likely to experience miscarriage than gravidae who did not. Gravidae who reported napping in the first trimester were less likely to experience miscarriage (p = 0.045), even after adjusting for confounding variables (p = 0.007). In conclusion, we found that screening positive on both the Berlin Questionnaire and Epworth Sleepiness Scale was statistically significantly associated with miscarriage prior to adjustment for confounding variables, as did snoring and hypertension. After adjusting for confounding variables, only not napping was associated with miscarriage. Given the small sample size, further investigation into this topic is warranted.

Hyperoxidized Peroxiredoxin 2 Is a Possible Biomarker for the Diagnosis of Obstructive Sleep Apnea

Peroxiredoxin (Prx) 2 in red blood cells (RBCs) reacts with various reactive oxygen species and changes to hyperoxidized Prx2 (Prx2-SO_2/3). Therefore, Prx2 may serve as an indicator of oxidative stress in vivo. This study aimed to analyze Prx2-SO_2/3 levels in clinical samples to examine whether the oxidation state of Prx2 in human RBCs reflects the pathological condition of oxidative stress diseases. We first focused on obstructive sleep apnea (OSA), a hypoxic stress-induced disease of the respiratory system, and investigated the levels of Prx2-SO_2/3 accumulated in the RBCs of OSA patients. In measurements on a small number of OSA patients and healthy subjects, levels of Prx2-SO_2/3 accumulation in patients with OSA were clearly increased compared to those in healthy subjects. Hence, we proceeded to validate these findings with more samples collected from patients with OSA. The results revealed significantly higher levels of erythrocytic Prx2-SO_2/3 in patients with OSA than in healthy subjects, as well as a positive correlation between the severity of OSA and Prx2-SO_2/3 levels in the RBCs. Moreover, we performed a chromatographic study to show the structural changes of Prx2 due to hyperoxidation. Our findings demonstrated that the Prx2-SO_2/3 molecules in RBCs from patients with OSA were considerably more hydrophilic than the reduced form of Prx2. These results implicate Prx2-SO_2/3 as a promising candidate biomarker for OSA.

Identification of metabolic fingerprints in severe obstructive sleep apnea using gas chromatography-Mass spectrometry

Objective: Obstructive sleep apnea (OSA) is considered a major sleep-related breathing problem with an increasing prevalence rate. Retrospective studies have revealed the risk of various comorbidities associated with increased severity of OSA. This study aims to identify novel metabolic biomarkers associated with severe OSA. Methods: In total, 50 cases of OSA patients (49.74 ± 11.87 years) and 30 controls (39.20 ± 3.29 years) were included in the study. According to the polysomnography reports and questionnaire-based assessment, only patients with an apnea-hypopnea index (AHI >30 events/hour) exceeding the threshold representing severe OSA patients were considered for metabolite analysis. Plasma metabolites were analyzed using gas chromatography-mass spectrometry (GC-MS). Results: A total of 92 metabolites were identified in the OSA group compared with the control group after metabolic profiling. Metabolites and their correlated metabolic pathways were significantly altered in OSA patients with respect to controls. The fold-change analysis revealed markers of chronic kidney disease, cardiovascular risk, and oxidative stress-like indoxyl sulfate, 5-hydroxytryptamine, and 5-aminolevulenic acid, respectively, which were significantly upregulated in OSA patients. Conclusion: Identifying these metabolic signatures paves the way to monitor comorbid disease progression due to OSA. Results of this study suggest that blood plasma-based biomarkers may have the potential for disease management.

Effect of Obstructive Sleep Apnea and CPAP Treatment on the Bioavailability of Erythrocyte and Plasma Nitric Oxide

INTRODUCTION

Endothelial dysfunction resulting from decreased nitric oxide (NO) bioavailability is an important mechanism that increases cardiovascular risk in subjects with obstructive sleep apnea (OSA). NO is produced by nitric oxide synthase (NOS) in a reaction that converts L-arginine to L-citrulline. Asymmetric-dimethylarginine (ADMA) is created by L-arginine and is a naturally occurring competitive inhibitor of nitric oxide synthase (NOS). The aim of our study was to verify if erythrocytes could play a role in the storage and accumulation of ADMA in OSA patients. The crosstalk between erythrocyte-ADMA, SDMA, L-arginine, and L-citrulline levels and endothelial function was investigated in OSA subjects both at baseline and prospectively following 1-year CPAP (continuous positive airway pressure) treatment.

MATERIAL AND METHODS

A total of 46 subjects with OSA were enrolled in this study and divided into two groups: those with moderate-to-severe OSA and those with mild or no OSA. A physical examination was followed by blood collection for the assessment of biochemical cardiovascular risk factors and the nitric oxide bioavailability parameters both in plasma and erythrocytes. Vasodilative endothelial function was assessed using Laser Doppler Flowmetry (LDF).

RESULTS

No significant changes regarding the NO pathway metabolites were noted apart from the plasma L-citrulline concentration, which was decreased in patients with OSA (26.9 ± 7.4 vs. 33.1 ± 9.4 μM, p < 0.05). The erythrocyte ADMA concentration was lower than in plasma irrespective of the presence of OSA (0.33 ± 0.12 vs. 0.45 ± 0.08 μM in OSA, p < 0.05 and 0.33 ± 0.1 vs. 0.45 ± 0.07 μM in the control, p < 0.05). No significant changes regarding the LDF were found. CPAP treatment did not change the levels of NO metabolites in the erythrocytes.

CONCLUSIONS

The erythrocyte pool of the NO metabolic pathway intermediates does not depend on OSA and its treatment, whereas the erythrocytes could constitute a high-volume buffer in their storage Hence, the results from this prospective study are a step forward in understanding the role of the erythrocyte compartment and the intra-erythrocyte pathways regulating NO bioavailability and paracrine endothelial function in the hypoxia-reoxygenation setting, such as obstructive sleep apnea.

Association between poor sleep quality and an increased risk of dry eye disease in patients with obstructive sleep apnea syndrome

Purpose

Obstructive sleep apnea (OSA) is related to an increased incidence of dry eye disease (DED). However, their exact relationship is unknown and requires further well-designed studies with advanced mechanisms detection.

Patients and methods

This case–control study included 125 OSA cases and 125 age–gender-matched controls enrolled in the hospital between 1 January and 1 October 2021. OSA diagnosis and classification were performed using a polysomnography (PSG) assay. Detailed ophthalmological examinations, including the Schirmer I test, corneal staining, and ocular surface disease index (OSDI), were used to detect DED-related parameters. A comprehensive ocular surface assay was performed to measure a series of parameters, including first non-invasive first tear film break-up time (f-NIBUT), average non-invasive first tear film break-up time (av-NIBUT), tear meniscus height (TMH), and loss of meibomian gland. In addition, the Pittsburgh Sleep Quality Index (PSQI) scale was used to assess sleep quality.

Results

Compared to the control, the OSA group showed an increased DED risk (P = 0.016) along with an increased PSQI score and a higher rate of poor quality sleep (P < 0.001 and P = 0.007, respectively). Stratification of OSA cases indicated that DED-related parameters were impaired in patients with severe OSA (P < 0.05). The analysis of DED-parameters-related factors showed significant correlations between OSA-related indexes and PSQI (P < 0.05). Moreover, the poor sleep quality group in the OSA cases showed worse DED-related parameters (P < 0.05), which was not observed in the control group.

Conclusion

OSA, especially the severe stage OSA, was related to an increased risk of DED. Also, sleep quality was correlated with the onset of both OSA and DED, where poor sleep quality revealed a relationship between OSA and the risk of DED. Overall, our findings provided evidence for advanced management of DED and OSA in future.

Comprehensive Metabolomics and Machine Learning Identify Profound Oxidative Stress and Inflammation Signatures in Hypertensive Patients with Obstructive Sleep Apnea

Obstructive sleep apnea (OSA) can aggravate blood pressure and increase the risk of cardiovascular diseases in hypertensive individuals, yet the underlying pathophysiological process is still incompletely understood. More importantly, OSA remains a significantly undiagnosed condition. In this study, a total of 559 hypertensive patients with and without OSA were included. Metabolome and lipidome-wide analyses were performed to explore the pathophysiological processes of hypertension comorbid OSA and derive potential biomarkers for diagnosing OSA in hypertensive subjects. Compared to non-OSA hypertensive patients (discovery set = 120; validation set = 116), patients with OSA (discovery set = 165; validation set = 158) demonstrated a unique sera metabolic phenotype dominated by abnormalities in biological processes of oxidative stress and inflammation. By integrating three machine learning algorithms, six discriminatory metabolites (including 5-hydroxyeicosatetraenoic acid, taurine, histidine, lysophosphatidic acid 16:0, lysophosphatidylcholine 18:0, and dihydrosphingosine) were selected for constructing diagnostic and classified model. Notably, the established multivariate-model could accurately identify OSA subjects. The corresponding area under the curve values and the correct classification rates were 0.995 and 96.8% for discovery sets, 0.997 and 99.1% for validation sets. This work updates the molecular insights of hypertension comorbid OSA and paves the way for the use of metabolomics for the diagnosis of OSA in hypertensive individuals.

Association between Health Literacy and Prevalence of Obesity, Arterial Hypertension, and Diabetes Mellitus

Background: Health literacy (HL) is linked to many health outcomes, including self-management of chronic diseases. The aim of this study was to assess the association of health literacy with the prevalence of obesity, arterial hypertension (AH), and type 2 diabetes mellitus (T2DM). Methods: This cross-sectional, single-center study included 500 patients (42.2% male and 57.8% females; median age, 63 years (interquartile range, 42−73)) hospitalized at General County Hospital in Požega, Croatia, between July and October 2020. The Short Assessment of Health Literacy for Croatian Adults (SAHLCA-50) questionnaire was used. Descriptive statistics (median with interquartile range (IQR), frequency, and percentages) and binary logistic regression were utilized. Results: Patients with AH had an inadequate level of health literacy as compared to those without AH (32 vs. 40 points; Mann−Whitney U test, p < 0.001). Patients with T2DM scored 31 points versus 39 points in patients without T2DM (Mann−Whitney U test, p < 0.001). Patients suffering from both AH and T2DM scored 31 points versus 33 points in those with either AH or T2DM and 41 points in patients without AH and T2DM (Kruskal−Wallis test, p < 0.001). There were no statistically significant differences in SAHLCA-50 scores according to the patient body mass index. Conclusions: An inadequate level of health literacy is significantly associated with AH and T2DM but not with obesity. Male gender, low level of education, rural place of residence, retirement, and older age are significant predictors of inadequate health literacy.

Contribution of Obstructive Sleep Apnoea to Cognitive Functioning of Males With Coronary Artery Disease: A Relationship With Endocrine and Inflammatory Biomarkers

Introduction

Our exploratory study aimed to determine whether obstructive sleep apnoea (OSA) could affect cognitive functioning in males with coronary artery disease (CAD), and whether such impact could be associated with changes in thyroid hormones and inflammatory marker regulation on cognitive functioning.

Method

We evaluated different endocrine and inflammatory biomarkers, including free triiodothyronine [fT3], free tetraiodothyronine [fT4], N-terminal pro-B-type natriuretic peptide [NT-pro-BNP], and high-sensitivity C-reactive protein [hs-CRP] serum levels in 328 males (x¯ = 57 ± 10 years), undergoing cardiac rehabilitation after an acute coronary event. Participants underwent full-night polysomnography and were classified in mild/non-OSA (n = 253) and OSA (n = 75) according to an apnoea-hypopnoea index ≥ 15 event/h. Cognitive functioning testing included the Digit Span Test, Digit Symbol Test (DSST), and Trail Making Test. Analyses of variance assessed the impact of OSA on cognitive functioning and possible relationships of fT3/fT4, NT-pro-BNP and with hs-CRP on cognitive measures.

Results

Significant group (OSA, mild/non-OSA) × NT-pro-BNP (<157.0 vs. ≥157.0, ng/L) interactions were found for the DSST raw score (F_(2,324) = 3.58, p = 0.014). Decomposition of interactions showed that the DSST scores of the OSA group with NT-pro-BNP ≥ 157.0 ng/L (M = 33.2; SD = 8.1) were significantly lower, p = 0.031, than those of the mild/non-OSA with NT-pro-BNP < 157.0 ng/L (M = 37.7; SD = 8.9).

Conclusion

These findings indicate that males with OSA and clinically elevated NT-pro-BNP levels experienced inferior psychomotor performance compared to those without OSA and reduced NT-pro-BNP levels.

Schisandrin B Diet Inhibits Oxidative Stress to Reduce Ferroptosis and Lipid Peroxidation to Prevent Pirarubicin-Induced Hepatotoxicity

Objective

Pirarubicin (THP) is one of anthracycline anticancer drugs. It is widely used in the treatment of various cancers, but its hepatotoxicity cannot be ignored. Schisandrin B (SchB) is a traditional liver-protecting drug, which has the ability to promote mitochondrial function and upregulate cellular antioxidant defense mechanism. However, whether it can resist THP-induced hepatotoxicity has not been reported. The purpose of this study was to observe and explore the effect of SchB on THP-induced hepatotoxicity and its potential mechanism by adding SchB to the diet of rats with THP-induced hepatotoxicity.

Methods

The rat model of THP-induced hepatotoxicity was established and partly treated with SchB diet. The changes of serum liver function indexes ALT and AST were observed. The histomorphological changes of liver were observed by HE staining. The biomarker levels of oxidative stress in rat serum and liver were measured to observe oxidative stress state. The expressions of ferroptosis-related protein GPX4 and oxidative stress-related protein were detected by Western blot. Primary hepatocytes were prepared and cocultured with THP, SchB, and Fer-1 to detect the production of reactive oxygen species (ROS) and verify the above signal pathways.

Results

THP rats showed a series of THP-induced hepatotoxicity changes, such as liver function damage, oxidative stress, and ferroptosis. SchB diet effectively alleviated these adverse reactions. Further studies showed that SchB had strong antioxidant and antiferroptosis abilities in THP-induced hepatotoxicity.

Conclusion

SchB has obvious protective effect on THP-induced hepatotoxicity. The mechanism may be closely related to inhibiting oxidative stress and ferroptosis in the liver.

Level of Serum Fetuin-A Correlates with Heart Rate in Obstructive Sleep Apnea Patients without Metabolic and Cardiovascular Comorbidities

Obstructive sleep apnea (OSA) is the most common type of sleep-induced breathing disorder in the adult population and significantly affects the condition of the cardiovascular system. Fetuin-A (Fet-A) is a hepato- and adipokine, which prevents vessel calcification, and its level correlates with atherogenesis and metabolic disorders. The associations of cardiovascular diseases (CVD) both with OSA, which increases CVD risk, and Fet-A, which prevents CVD, justify the question of their mutual interactions in patients with OSA. Therefore, we sought to analyze Fet-A as an early biomarker of CVD risk in OSA patients without metabolic and cardiovascular comorbidities except for properly controlled arterial hypertension. We have found that in these patients, OSA does not appear to directly affect Fet-A levels. However, high Fet-A levels were more common in the group of patients with OSA, and the hypopnea index was significantly higher among subjects with the highest Fet-A levels. The level of Fet-A in OSA patients positively correlates with pulse rate, and it does not correlate with pulse pressure in this group unlike in the control group, where such a relationship exists. To our best knowledge, this is the first study to analyze this relationship in OSA patients without any significant cardiovascular comorbidities.

Hypoxia and hemorheological properties in older individuals

Hypoxia is caused by insufficient oxygen availability for the organism leading to reduced oxygen delivery to tissues and cells. It has been regarded as a severe threat to human health and it is indeed implicated in pathophysiological mechanisms involved in the development and progression of many diseases. Nevertheless, the potential of controlled hypoxia interventions (i.e. hypoxia conditioning) for improving cardio-vascular health is gaining increased attention. However, blood rheology is often a forgotten factor for vascular health while aging and hypoxia exposure are both suspected to alter hemorheological properties. These changes in blood rheology may influence the benefits-risks balance of hypoxia exposure in older individuals. The benefits of hypoxia exposure for vascular health are mainly reported for healthy populations and the combined impact of aging and hypoxia on blood rheology could therefore be deleterious in older individuals. This review discusses evidence of hypoxia-related and aging-related changes in blood viscosity and its determinants. It draws upon an extensive literature search on the effects of hypoxia/altitude and aging on blood rheology. Aging increases blood viscosity mainly through a rise in plasma viscosity, red blood cell (RBC) aggregation and a decrease in RBC deformability. Hypoxia also causes an increase in RBC aggregation and plasma viscosity. In addition, hypoxia exposure may increase hematocrit and modulate RBC deformability, depending on the hypoxic dose, i.e, beneficial effect of intermittent hypoxia with moderate dose vs deleterious effect of chronic continuous or intermittent hypoxia or if the hypoxic dose is too high. Special attention is directed toward the risks vs. benefits of hemorheological changes during hypoxia exposure in older individuals, and its clinical relevance for vascular disorders.

Nitrotyrosine, Nitrated Lipoproteins, and Cardiovascular Dysfunction in Patients with Type 2 Diabetes: What Do We Know and What Remains to Be Explained?

Diabetes mellitus (DM) is a strong risk factor for the development of cardiovascular diseases (CVDs), which are the most important cause of morbidity and mortality in the population of patients living with DM. DM is associated with lipid metabolism disorders characterized by a decrease in the high-density lipoprotein blood concentration, an increase in the triglyceride blood concentration, and the presence of modified lipoproteins not routinely measured in clinical practice. Nitrated lipoproteins are produced by the nitration of the tyrosyl residues of apolipoproteins by myeloperoxidase. There is some evidence from the research conducted showing that nitrated lipoproteins may play a role in the development of cardiovascular dysfunction, but this issue requires further investigation. It was found that the nitration of HDL particles was associated with a decrease in caspase-3 and paraoxonase-1 activity, as well as a decrease in the activity of cholesterol transport via ABCA1, which reduces the protective effect of HDL particles on the cardiovascular system. Less information has been collected about the role of nitrated LDL particles. Thus far, much more information has been obtained on the relationship of nitrotyrosine expression with the presence of cardiovascular risk factors and the development of cardiovascular dysfunction. The purpose of this paper is to provide an extensive review of the literature and to present the most important information on the current state of knowledge on the association between nitrotyrosine and nitrated lipoproteins with dysfunction of the cardiovascular system, especially in patients living with DM. Moreover, directions for future research in this area were discussed.