The association of hemocyte profile and obstructive sleep apnea

Obstructive Sleep Apnea, Platelet Aggregation, and Cardiovascular Risk

BACKGROUND

Although related, the precise mechanisms linking obstructive sleep apnea (OSA) and cardiovascular disease (CVD) are unclear. Platelets are mediators of CVD risk and thrombosis and prior studies suggested associations of OSA and platelet activity. The aim of this study is to assess the link between OSA, platelet activity, and CVD-related risk factors.

METHODS AND RESULTS

We studied the association of OSA-measures and platelet aggregation in participants dually enrolled in the SHHS (Sleep Heart and Health Study) and FHS (Framingham Heart Study). We applied linear regression models with adjustment for demographic and clinical covariates and explored interactions with OSA and CVD-related factors, including age, sex, body mass index, hypertension, OSA diagnosis (apnea-hypopnea index 4%≥5), and aspirin use. Our final sample was of 482 participants (60 years [14.00], 50.4% female). No associations were observed between apnea-hypopnea index 4% and platelet aggregation in the main sample. Stratified analysis revealed an association in aspirin users (n=65) for our primary exposure (apnea-hypopnea index 4%, β=0.523; P<0.001; n=65), and secondary exposures: hypoxic burden (β=0.358; P<0.001), minimum saturation (β=-0.519; P=0.026), and oxygen desaturation index 3% (β=74.672; P=0.002). No associations were detected in nonaspirin users (n=417).

CONCLUSIONS

No associations were detected between OSA and platelet aggregation in a community sample. Our finding that OSA associates with increased platelet aggregation in the aspirin group, most of whom use it for primary prevention of CVD, suggests that platelet aggregation may mediate the adverse impact of OSA on vascular health in individuals with existing CVD risk, supporting further investigation.

Obstructive sleep apnea and cardiovascular risk

Patients with obstructive sleep apnea (OSA) experience repetitive episodes of upper airway obstruction due to recurrent collapse during sleep. This leads to intermittent hypoxia episodes, which, through complex pathophysiological mechanisms, trigger sympathetic overactivation, endothelial dysfunction, hypercoagulation, and metabolic dysregulation. Consequently, other cardiovascular risk factors such as hypertension, metabolic syndrome, and diabetes are induced. Furthermore, this enhances target organ damage, affecting the heart, arteries, and kidneys, leading to an increased risk of cardiovascular morbidity and mortality. Among the various treatments for OSA, Continuous Positive Airway Pressure (CPAP) has been extensively studied. To date, this treatment has shown mild benefits in reducing blood pressure, particularly noticeable in patients with resistant hypertension. Furthermore, CPAP treatment appears to reduce cardiovascular events, both in primary and secondary prevention, though this benefit is limited to individuals with good compliance (CPAP use ≥4h/night). Future research perspectives in OSA seem to focus on identifying patients in whom the condition significantly influences cardiovascular risk, thus determining those who would benefit the most from treatment in the reduction of cardiovascular risk.

The relationship between haemoglobin concentrations and obstructive sleep apnea syndrome: A systematic review and meta-analysis

BACKGROUND

This systematic review and meta-analysis investigates the relationship between haemoglobin (Hb) concentrations and obstructive sleep apnea syndrome (OSAS).

METHODS

Following PRISMA guidelines, we searched PubMed, EMBASE, and Cochrane Library from inception to March 8, 2024. Eligible studies included cross-sectional, cohort, and case-control designs comparing Hb concentrations in OSAS patients and healthy controls. Two reviewers independently screened records and extracted data. The risk of bias was assessed using the Joanna Briggs Institute checklist.

RESULTS

A total of 27 studies involving 6499 OSAS subjects and 5199 controls were included. Hb concentrations were significantly higher in OSAS patients compared to controls (SMD: 0.28; 95 % CI: 0.18 to 0.39; I2 = 84.4 %). Subgroup analysis by OSAS severity showed that severe OSAS patients had higher Hb concentrations than those with mild/moderate OSAS. Sensitivity analyses confirmed the robustness of the findings. However, 7 studies reported opposite results, indicating possible regional or methodological differences.

CONCLUSION

Hb concentrations are elevated in OSAS patients, with higher levels observed in severe cases. The significant heterogeneity and the predominance of studies from Turkey highlight the need for further research in diverse populations. Limitations include potential publication bias and variability in study designs.

Differences and Risk Factors of Peripheral Blood Immune Cells in Patients with Obstructive Sleep Apnea

Introduction

Obstructive sleep apnea (OSA) is a respiratory disorder characterized by chronic intermittent hypoxia and fragmented sleep, leading to inflammatory response and oxidative stress. However, the differences in immune inflammatory response in OSA patients with different severity remain unclear.

Purpose

This study aims to examine the differences in peripheral blood immune cells and their risk factors in OSA patients.

Patients and Methods

A total of 277 snoring patients from the Sleep Respiratory Disorder Monitoring Center of Zhongnan Hospital of Wuhan University were recruited in this study. According to the diagnosis and severity criteria of OSA, the included patients were further divided into simple snoring, mild, moderate, and severe groups. Peripheral blood immune cell counts including white blood cells, neutrophils, lymphocytes, monocytes, eosinophils, basophils, red blood cells, platelets, and polysomnography indicators were collected from the patients.

Results

Compared with simple snoring patients, the OSA patients had increased circular monocyte and basophil count levels. In addition, correlation analysis results indicated that monocyte count was positively associated with chronic obstructive pulmonary disease (COPD), smoking, apnea-hypopnea index (AHI), the longest apnea duration, and Oxygen desaturation index (ODI), and negatively correlated with average SpO2 in snoring patients. Finally, multiple linear regression analysis revealed that AHI, COPD, smoking, and maximum heart rate were independent predictors of monocyte count.

Conclusion

OSA patients had a significant increase in their peripheral blood monocyte count. AHI, COPD, smoking, and maximum heart rate were risk factors for increased peripheral blood monocyte count in OSA patients. These findings suggest that peripheral blood monocytes can be considered an inflammatory biomarker of OSA.

Sleep status of older adults with sleep apnoea syndrome may vary by body mass index

Obesity and ageing are the most important risk factors for sleep apnoea syndrome (SAS); however, the role of body mass index (BMI) on sleep status in healthy older adults is unclear. To explore sleep parameters according to BMI among active older adults, we cross-sectionally examined the relationship between sleep-related parameters and BMI in 32 Japanese adults aged from 83 to 95 years without long-term care who were unaware of having SAS. Correlation and linear regression analyses were performed. Moderate or severe SAS prevalence was high in both those with low (68.8%) and high (68.8%) BMI. A higher increase in apnoea-hypopnoea index (AHI) was negatively correlated with sleep depth in the high-BMI group. In the low-BMI group, the number of awakenings and age were positively correlated with AHI. Older adults may have SAS regardless of their BMI, and the sleep status of patients with SAS may vary by BMI.

Exploring the Dynamics of Sleep Deprivation: Insights into Complete Blood Count and Coagulation Parameters in a Case-Control Study

Background

The lack of preceding research in Sudan emphasizes the importance of this study, which contributes critical data to the global understanding of sleep-related health effects. This study investigates the complex relationship between sleep deprivation and blood-related factors, particularly focusing on full blood count and coagulation parameters.

Methods

From January to March 2022, a case-control study was conducted in Kosti, Sudan. A control group of 11 healthy 23-33-year-olds (6 men and 5 women) had regular sleep patterns. Six men and five women ages 23-33 were chosen for this sleep-deprived case study. The case group was deprived of sleep from 7:00 p.m. to 7:00 a.m. for three days and allowed to sleep normally during the day. Daily at 7:00 a.m., antecubital vein blood was drawn. The ACL 7000 coagulation analyzer and Sysmex fully automated hematology analyzers were used for coagulation and whole blood count analysis. Data analysis included descriptive and inferential approaches like the Mann-Whitney U test for group comparisons.

Results

The study found no significant differences in total white blood cell counts reported between case and control groups (p=0.898). The case group had a substantial drop in lymphocyte counts on day 3 (p=0.016). The third day showed significant differences in neutrophil and eosinophil levels (p=0.003 and 0.000, respectively). The difference in hemoglobin and hematocrit on day 3 was statistically significant (p=0.023). Platelet counts were stable. Both groups' prothrombin times were unaffected. On all three days, groups had significant differences in activated partial thromboplastin time (APTT) (p=0.004). Therefore, the intrinsic coagulation system may have changed.

Conclusion

This study demonstrates the complex link between sleep deprivation, coagulation indicators, and complete blood count. Monitoring blood indicators in poor sleep helps explain fundamental mechanisms and medicinal implications.

Development and Validation of a Nomogram Model to Predict Obstructive Sleep Apnea

Objectives: Polysomnography was class I test for who was suspected of obstructive sleep apnea (OSA) which would cost lots of time and money. This study aimed to develop a nomogram model mainly based on oxygen and blood routine indicators to predict OSA. Methods: We retrospectively analyzed 685 patients with suspected OSA at our hospital. Multivariate analysis was used to construct a nomogram. The performance of the nomogram was assessed using calibration and discrimination. Results: The multivariate analysis identified age, gender, body mass index, mean pulse oxygen saturation, percent nighttime with oxygen saturation less than 90%, red blood cell, hematocrit, and red blood cell distribution width SD as significant factors (P < .05). A nomogram was created for the prediction of OSA using these clinical parameters and was internally validated using a bootstrapping method. Our nomogram model showed good discrimination and calibration in terms of predicting OSA, and had a C-index of 0.935 [95% confidence interval (CI), 0.917-0.954] according to the internal validation. Discrimination and calibration in the validation group were also good (C-index, 0.957; 95% CI, 0.930-0.984). Conclusion: The newly developed nomogram can effectively help physicians make better clinical decisions, which may save a lot of time and costs.

Low Hemoglobin Level and Elevated Inflammatory Hematological Ratios Associated With Depression and Sleep Disturbance

BACKGROUND

The relationship between blood cell profiles, including hemoglobin (Hb) levels and inflammatory hematological ratios, and mental health problems currently remains unclear.

AIM

This study aimed to investigate the relationship between blood cell profiles and mental health issues, including depressive state and sleep disturbance, while adjusting for potential demographic confounders.

METHODOLOGY

This retrospective, cross-sectional, observational study used a population-based medical database from the Tohoku Medical Megabank Project with more than 60,000 volunteers. Data on age, sex, daily tobacco use, body mass index, and self-reported scores on the Kessler Psychological Distress Scale (K6), Athens Insomnia Scale (AIS), and the Center for Epidemiologic Studies Depression Scale (CES-D) were collected.

RESULTS

A total of 62,796 volunteers (23,663 males and 39,133 females), aged ≥20 years at the time of the blood test, agreed to participate in this study. Among the evaluated blood cell profiles, Hb, hematocrit, neutrophil-to-lymphocyte ratio (NLR), and platelet-to-lymphocyte ratio (PLR) were significantly correlated with the K6, AIS, and CES-D scores, with strong statistical significance (p<0.0001 for all) in bivariate correlation analyses. A significant adjusted odds ratio (aOR) of the Hb level for elevated CES-D scores (aOR=0.965 [95% CI: 0.949-0.981], p<0.0001) was confirmed after adjusting for demographic data and daily tobacco use using a logistic regression model. Sensitivity analyses revealed that these associations existed in both males and females but were more prominent in the former. In male participants, a low Hb level was significantly associated with an elevated AIS score. The evaluated inflammatory hematological ratios, including NLR, PLR, and monocyte-to-lymphocyte ratio (MLR), also showed significant aORs with the K6, AIS, and CES-D scores after adjusting for demographic background.

CONCLUSION

Low Hb levels and elevated inflammatory hematological ratios (NLR, MLR, and PLR) were associated with depressive state and sleep disturbances in the general population.

Prediction of adverse events risk in patients with comorbid post-traumatic stress disorder and alcohol use disorder using electronic medical records by deep learning models

BACKGROUND

Identifying co-occurring mental disorders and elevated risk is vital for optimization of healthcare processes. In this study, we will use DeepBiomarker2, an updated version of our deep learning model to predict the adverse events among patients with comorbid post-traumatic stress disorder (PTSD) and alcohol use disorder (AUD), a high-risk population.

METHODS

We analyzed electronic medical records of 5565 patients from University of Pittsburgh Medical Center to predict adverse events (opioid use disorder, suicide related events, depression, and death) within 3 months at any encounter after the diagnosis of PTSD+AUD by using DeepBiomarker2. We integrated multimodal information including: lab tests, medications, co-morbidities, individual and neighborhood level social determinants of health (SDoH), psychotherapy and veteran data.

RESULTS

DeepBiomarker2 achieved an area under the receiver operator curve (AUROC) of 0.94 on the prediction of adverse events among those PTSD+AUD patients. Medications such as vilazodone, dronabinol, tenofovir, suvorexant, modafinil, and lamivudine showed potential for risk reduction. SDoH parameters such as cognitive behavioral therapy and trauma focused psychotherapy lowered risk while active veteran status, income segregation, limited access to parks and greenery, low Gini index, limited English-speaking capacity, and younger patients increased risk.

CONCLUSIONS

Our improved version of DeepBiomarker2 demonstrated its capability of predicting multiple adverse event risk with high accuracy and identifying potential risk and beneficial factors.

A Systematic Review and Meta-Analysis of Mean Platelet Volume and Platelet Distribution Width in Patients with Obstructive Sleep Apnoea Syndrome

Obstructive sleep apnoea syndrome (OSAS) is a highly prevalent yet underestimated disorder caused by the complete or partial obstruction of the upper airways. Although polysomnography is the gold standard for OSAS diagnosis, there is an active search for easily accessible biomarkers of disease presence and severity, particularly those reflecting morphological changes in specific blood cells. We investigated the associations between the presence and severity of OSAS, continuous positive airway pressure (CPAP) treatment, mean platelet volume (MPV), and platelet distribution width (PDW), routinely assessed as part of the complete blood count. From 262 retrieved records from PubMed, the Web of Science, Scopus, and Google Scholar, 31 manuscripts were selected for a final analysis, 30 investigating MPV and 15 investigating PDW. MPV was not statistically different between OSAS patients and healthy controls; however, it progressively increased with disease severity. By contrast, OSAS patients had significantly higher PDW values than controls (SMD = 0.40, 95% CI: 0.25 to 0.56; p ˂ 0.001), and the difference increased with disease severity. In a univariate meta-regression, there were significant associations between the MPV and publication year, the apnoea-hypopnea index, and diabetes mellitus, while no associations were observed with the PDW. No significant between-group differences were observed in the subgroup analyses. These data suggest that PDW, and to a lesser extent, MPV, are potential biomarkers of OSAS and require further research to ascertain their pathophysiological significance (PROSPERO, CRD42023459413).

Association between Red Blood Cell Distribution Width and Obstructive Sleep Apnea Syndrome: A Systematic Review and Meta-Analysis

Although polysomnography is the gold standard method to diagnose obstructive sleep apnea syndrome (OSAS), there is an ongoing quest for simpler and relatively inexpensive biomarkers of disease presence and severity. To address this issue, we conducted a systematic review of the potential diagnostic role of the red blood cell distribution width (RDW), a routine hematological parameter of red blood cell volume variability, in OSAS. A total of 1478 articles were initially identified in the databases PubMed, Web of Science, Scopus, Embase, and Google Scholar, from their inception to February 2023, and 20 were selected for final analysis. The RDW was significantly higher in OSAS than in non-OSAS subjects (SMD = 0.44, 95% CI 0.20 to 0.67, p < 0.001; low certainty of evidence). In univariate meta-regression, the mean oxygen saturation (SpO₂) was significantly associated with the effect size. No significant between-group differences were observed in subgroup analyses. Notably, in OSAS subjects, the RDW SMD progressively increased with disease severity. In conclusion, these results suggest that the RDW is a promising biomarker of OSAS (PROSPERO registration number: CRD42023398047).

The Associations of Platelet Activation and Coagulation Parameters with Obstructive Sleep Apnoea: A Large-Scale Observational Study

OBJECTIVES

Obstructive sleep apnoea (OSA) is associated with an increased risk of cardiovascular disease, with alterations in coagulability suspected as the mediating factor. This study explored blood coagulability and breathing-related parameters during sleep in patients with OSA.

DESIGN

Cross-sectional observational study. Setting. Shanghai Sixth People's Hospital. Participants. 903 patients diagnosed by standard polysomnography. Main Outcome and Measures. The relationships between coagulation markers and OSA were evaluated using Pearson's correlation, binary logistic regression, and restricted cubic spline (RCS) analyses.

RESULTS

The platelet distribution width (PDW) and activated partial thromboplastin time (APTT) decreased significantly with increasing OSA severity (both p < 0.001). PDW was positively associated with the apnoea-hypopnea index (AHI), oxygen desaturation index (ODI), and microarousal index (MAI) (ß = 0.136, p < 0.001; ß = 0.155, p < 0.001; and ß = 0.091, p = 0.008, respectively). APTT was negatively correlated with AHI (ß = -0.128, p < 0.001) and ODI (ß = -0.123, p = 0.001). PDW was negatively correlated with percentage of sleep time with oxygen saturation below 90%(CT90) (ß = -0.092, p = 0.009). The minimum arterial oxygen saturation (SaO₂) correlated with PDW (ß = -0.098, p = 0.004), APTT (ß = 0.088, p = 0.013), and prothrombin time (PT) (ß = 0.106, p = 0.0003). ODI was risk factors for PDW abnormalities (odds ratio (OR) = 1.009, p = 0.009) after model adjustment. In the RCS, a nonlinear dose-effect relationship was demonstrated between OSA and the risk of PDW and APTT abnormalities.

CONCLUSION

Our study revealed nonlinear relationships between PDW and APTT, and AHI and ODI, in OSA, with AHI and ODI increasing the risk of an abnormal PDW and thus also the cardiovascular risk. This trial is registered with ChiCTR1900025714.

The Overlap Syndrome of Obstructive Sleep Apnea and Chronic Obstructive Pulmonary Disease: A Systematic Review

Chronic obstructive pulmonary disease (COPD) and obstructive sleep apnea (OSA) are common diseases that strongly impact the quality and length of life. Their coexistence is determined by overlap syndrome (OS). This systematic review aims to define the significance of these comorbidities according to the current state of knowledge. For this systematic review, we searched PubMed, Scopus, and Cochrane for studies published between 2018 and 26 October 2022, to find original, observational, human studies published in English, where the diagnosis of COPD was according to the Global Initiative for Obstructive Lung Disease guidelines and the diagnosis of OSA was based on polysomnography. The quality of studies was assessed using the Newcastle-Ottawa quality assessment tool for cohort and case-control studies, as well as its modification for cross-sectional studies. Of the 1548 records identified, 38 were eligible and included in this systematic review. The included studies covered a total population of 27,064 participants. This paper summarizes the most important, up-to-date information regarding OS, including the prevalence, meaning of age/gender/body mass index, polysomnography findings, pulmonary function, comorbidities, predicting OSA among COPD patients, and treatment of this syndrome.

Super-multifactorial survey YHAB revealed high prevalence of sleep apnoea syndrome in unaware older adults and potential combinatorial factors for its initial screening

Study Objectives: Aging is a risk factor for sleep apnoea syndrome (SAS), which is associated with lower quality of life and sudden mortality. However, SAS is often overlooked in older adults without suspicions. Therefore, this study aimed to evaluate SAS incidence and 48 other general factors in older adults. Methods: This cross-sectional study included all non-caregiver-certified, healthy individuals (N = 32) who survived during the long-term cohort study and agreed to participate in apnoea-hypopnoea index (AHI) measurement (aged 83-95 years). AHI and 48 other general factors were evaluated, and simple linear regression analysis was used to identify potential AHI-related factors. Stepwise evaluation was further performed using multiple linear regression analyses. Results: Although no individuals were previously diagnosed with SAS, 30 (93.75%) participants had some degree of SAS (AHI > 5/h), and 22 (68.75%) had severe or moderate SAS (AHI > 15/h). Compared with typical single risk factors represented by body mass index, combining daily steps and other factors improved the fit to the multiple linear regression. Combining daily steps and body mass index improved the fit for males and combining daily steps and red blood cell count improved the fit for females. Conclusion: SAS was highly prevalent in unaware healthy Japanese older adults; combinations of daily steps and body mass index, and daily steps and red blood cell count may predict AHI in such individuals without the need for a specific AHI test.

Associations among sleep, hematologic profile, and aerobic and anerobic capacity of young swimmers: A complex network approach

Although the link between sleep and hematological parameters is well-described, it is unclear how this integration affects the swimmer’s performance. The parameters derived from the non-invasive critical velocity protocol have been extensively used to evaluate these athletes, especially the aerobic capacity (critical velocity—CV) and the anaerobic work capacity (AWC). Thus, this study applied the complex network model to verify the influence of sleep and hematological variables on the CV and AWC of young swimmers. Thirty-eight swimmers (male, n = 20; female, n = 18) completed five experimental evaluations. Initially, the athletes attended the laboratory facilities for venous blood collection, anthropometric measurements, and application of sleep questionnaires. Over the 4 subsequent days, athletes performed randomized maximal efforts on distances of 100, 200, 400, and 800-m. The aerobic and anerobic parameters were determined by linear function between distance vs. time, where CV relates to the slope of regression and AWC to y-intercept. Weighted but untargeted networks were generated based on significant (p < 0.05) correlations among variables regardless of the correlation coefficient. Betweenness and eigenvector metrics were used to highlight the more important nodes inside the complex network. Regardless of the centrality metric, basophils and red blood cells appeared as influential nodes in the networks with AWC or CV as targets. The role of other hematologic components was also revealed in these metrics, along with sleep total time. Overall, these results trigger new discussion on the influence of sleep and hematologic profile on the swimmer’s performance, and the relationships presented by this targeted complex network can be an important tool throughout the athlete’s development.

DeepBiomarker: Identifying Important Lab Tests from Electronic Medical Records for the Prediction of Suicide-Related Events among PTSD Patients

Identifying patients with high risk of suicide is critical for suicide prevention. We examined lab tests together with medication use and diagnosis from electronic medical records (EMR) data for prediction of suicide-related events (SREs; suicidal ideations, attempts and deaths) in post-traumatic stress disorder (PTSD) patients, a population with a high risk of suicide. We developed DeepBiomarker, a deep-learning model through augmenting the data, including lab tests, and integrating contribution analysis for key factor identification. We applied DeepBiomarker to analyze EMR data of 38,807 PTSD patients from the University of Pittsburgh Medical Center. Our model predicted whether a patient would have an SRE within the following 3 months with an area under curve score of 0.930. Through contribution analysis, we identified important lab tests for suicide prediction. These identified factors imply that the regulation of the immune system, respiratory system, cardiovascular system, and gut microbiome were involved in shaping the pathophysiological pathways promoting depression and suicidal risks in PTSD patients. Our results showed that abnormal lab tests combined with medication use and diagnosis could facilitate predicting SRE risk. Moreover, this may imply beneficial effects for suicide prevention by treating comorbidities associated with these biomarkers.

Obstructive Sleep Apnea as a Risk Factor for Venous Thromboembolism: A Systematic Review

Obstructive sleep apnea (OSA), is a prevalent condition characterized by repeated episodes of pharyngeal airway obstruction resulting in hypopnea and apnea episodes during sleep leading to nightly awakenings. OSA is a major contributor to the healthcare burden worldwide due to its high cardiovascular morbidity and mortality. There is growing evidence to support a pathophysiological link between OSA and venous thromboembolism (VTE). The pro-inflammatory state along with intermittent hypoxia that is invoked in OSA is associated with blood hypercoagulability, venous stasis, and endothelial dysfunction leading to deep vein thrombosis (DVT) and pulmonary embolism (PE). In this systematic review, we aim to analyze and assess the available literature on OSA and VTE (or DVT/PE) to determine whether OSA is an independent risk factor for VTE.

Is obstructive sleep apnea associated with erythrocytosis? A systematic review and meta‐analysis

Objective

The aim of this systematic review and meta‐analysis was to investigate the association between obstructive sleep apnea (OSA) and erythrocytosis.

Methods

The PubMed, Web of Science, and Cochrane Library databases were searched for articles examining hematocrit values in patients with OSA and control individuals published till September 1, 2021. The pooled standardized mean difference (SMD) with 95% confidence interval (CI) was calculated, and subgroup analyses were performed.

Results

Eleven eligible studies with a total of 4608 patients with OSA were included in this meta‐analysis. Pooled outcomes revealed that hematocrit values were significantly higher in patients with OSA than in controls (SMD, 0.19; 95% CI, 0.08–0.29; p < .01). When studies were stratified by disease severity, the significant differences in hematocrit values between patients and controls were only observed in the severe OSA group (SMD, 0.34; 95% CI, 0.08–0.59; p < .01), but not in the mild and moderate OSA groups. In subgroup analyses according to sex and publication year, significant differences in hematocrit values between patients and controls remained stable in studies with only female patients (SMD, 0.25; 95% CI, 0.12–0.38; p < .01) and in studies published after 2012 (SMD, 0.17; 95% CI, 0.06–0.28, p < .01).

Conclusion

Our meta‐analysis revealed that the hematocrit value was significantly increased in patients with OSA, particularly in severe patients, compared with that in controls. However, the elevation was modest, and the hematocrit value is expected to be within the normal range in patients with OSA. These data suggest that OSA leads to slight increases in hematocrit but does not cause clinically significant erythrocytosis.

Obstructive Sleep Apnea is Associated with an Increased Prevalence of Polycythemia in Patients with Chronic Obstructive Pulmonary Disease

Purpose

Chronic obstructive pulmonary disease (COPD) and obstructive sleep apnea (OSA) are associated with polycythemia. However, there still remain unanswered questions about the relationship between overlap syndrome (OVS), where OSA and COPD coexist, and polycythemia. Here, we aimed to establish the prevalence of polycythemia in OVS patients and to explore the impact of OSA on polycythemia.

Patients and Methods

Patients with COPD underwent overnight polysomnography (PSG), pulmonary function tests, echocardiography, and complete blood counts. All patients were ethnic Han Chinese and free of prolonged oral corticosteroid use, hematological system disease, severe systemic disease, and other sleep-disordered breathing. OVS was defined as COPD patients with an apnea–hypopnea index ≥15 events/h, and polycythemia was defined as an Hb >165 g/L in men and >160 g/L in women.

Results

Eight-hundred and eighty-six patients with COPD were included in the analysis. The prevalence of polycythemia was significantly higher in OVS patients than COPD-alone patients (6.4% vs 2.9%, p < 0.05). The prevalence of polycythemia increased with OSA severity (χ² = 7.885, p = 0.007), but not in GOLD grade 3–4 COPD patients (χ² = 0.190, p = 0.663). After adjusting for confounders, percentage of total sleep time with SaO₂ <90% (TS₉₀) remained independently associated with an increased odds of polycythemia (OR 1.030, 95% CI 1.015–1.046) and, with an increase in TS₉₀, the hemoglobin increased, especially in GOLD grade 1–2 patients (p < 0.05).

Conclusion

Patients with OVS have a higher prevalence of polycythemia than those with COPD alone, and TS₉₀ is an independent factor for polycythemia, especially in GOLD1-2 COPD patients.

Whole blood gene expression signature in patients with obstructive sleep apnea and effect of continuous positive airway pressure treatment

The molecular mechanisms of obstructive sleep apnea (OSA), in particular the gene expression patterns in whole blood of patients with OSA, can shed more light on the underlying pathophysiology of OSA and suggest potential biomarkers. In the current study, we have enrolled thirty patients with untreated moderate-severe OSA together with 20 BMI, age, and sex-matched controls and 15 normal-weight controls. RNA-sequencing of whole blood and home sleep apnea testing were performed in the untreated state and after three and twelve months of continuous positive airway pressure (CPAP) treatment. Analysis of the whole blood transcriptome of the patients with OSA revealed a unique pattern of differential expression with a significant number of downregulated immune-related genes including many heavy and light chain immunoglobulins and interferon-inducible genes. This was confirmed by the gene ontology analysis demonstrating enrichment with the biological processes associated with various immune functions. Expression of these genes was recovered after three months of CPAP treatment. After 12 months of CPAP treatment, the overall gene expression profile returns to the initial, untreated level. In addition, we have confirmed the importance of choosing BMI-matched controls as a reference group as opposed to normal-weight healthy individuals based on the significantly different gene expression signatures between these two groups.

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

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

Can the complete blood count be used as a reliable screening tool for obstructive sleep apnea?

PURPOSE

Since hypoxia increases erythropoietin production and inflammation, the complete blood count (CBC) has been proposed as an inexpensive alternative for obstructive sleep apnea (OSA) screening. The objective of this study was to determine whether or not intermittent hypoxia and OSA severity, as measured by the mean oxygen saturation (SpO₂) and apnea-hypopnea index (AHI), affect parameters measured by the CBC.

METHODS

This retrospective study included a total of 941 surgical patients who had a pre-operative home sleep study. The pre-operative CBC was extracted from the electronic patient records. Patients were stratified according to their AHI scores, into mild (AHI ≥ 5 - < 15), moderate (AHI ≥ 15 - < 30), and severe (AHI ≥ 30) OSA groups.

RESULTS

There were 244 patients without OSA, 294 with mild, 223 with moderate, and 180 with severe OSA. Our analysis showed that hemoglobin (P = 0.010), hematocrit (P = 0.027), and basophils (P = 0.006) showed significant changes among the different severities of OSA. For mean SpO₂, there were negative associations with body mass index (r =  - 0.287; P < 0.001), age (r =  - 0.077; P = 0.021), hemoglobin (r =  - 0.208; P < 0.001), hematocrit (r =  - 0.220; P < 0.001), red blood cells (r =  - 0.107; P = 0.001), mean corpuscular volume (MCV) (r =  - 0.159; P < 0.001), mean corpuscular hemoglobin (r =  - 0.142; P < 0.001), and basophils (r =  - 0.091; P = 0.007). All analyzed parameters remained within normal clinical range. Multivariable regression identified hemoglobin, MCV, and basophils to be independent predictors of mean SpO₂ and AHI.

CONCLUSION

Hemoglobin, MCV, and basophils were independently associated with intermittent hypoxia defined by mean SpO₂ and AHI. Adding CBC parameters to other screening tools for OSA may have additional value due to its association with changes in mean SpO_2.

Red cell distribution width: a new tool for the severity prediction of sleep apnoea syndrome in children

Introduction

Red cell distribution width (RDW) is a parameter included in the complete blood count which informs about the size of the circulating red blood cell population and its distribution. In adults, an increase in RDW was shown to be associated both with obstructive sleep apnoea (OSA) and with an increase in cardiovascular mortality. The aim of this study was to determine whether RDW is a potential biomarker for screening children with moderate–severe OSA.

Methods

An observational study in snoring patients was performed. All patients underwent a sleep study and were classified either as simple snorers (apnoea–hypopnoea index (AHI) <1 event·h⁻¹) or as patients with OSA (mild AHI ≥1 to <5 events·h⁻¹; moderate–severe AHI ≥5 events·h⁻¹). Blood analyses (complete blood count and C-reactive protein) were performed for every individual.

Results

A total of 175 individuals were recruited. The mean age was 8.3±3.6 years. Correlation studies between RDW and several sleep-related parameters showed negative significant associations with minimum oxygen saturation, and positive significant associations with oxygen desaturation index (≥3% and ≥4%), AHI and the arousal index. A predictive model for paediatric severe OSA (AHI ≥5 events·h⁻¹) was found based on mean corpuscular haemoglobin concentration (MCHC) <34.9 g·dL⁻¹ and RDW >13.1% values, adjusting for body mass index z-score and age (area under the curve 0.657; p=0.004). In addition, differences were found in eosinophil count and C-reactive protein concentrations among the three subgroups.

Conclusions

In children, RDW stands out as a biomarker associated with the severity of OSA. The use of RDW and MCHC could be a simple but useful tool for the severity prediction of paediatric OSA in snoring patients.

Red cell distribution width and mean corpuscular haemoglobin concentration are blood markers associated with the severity of paediatric OSAhttps://bit.ly/2Asw1xa

Impaired intestinal barrier in patients with obstructive sleep apnea

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.

Association between the neutrophil-to-lymphocyte ratio and obstructive sleep apnea: a meta-analysis

This meta-analysis is aimed to investigate the association between the neutrophil-to-lymphocyte ratio (NLR) and obstructive sleep apnea (OSA). The PubMed, Web of Science, Google Scholar, and Cochrane Library databases were searched to collect all relevant articles. The pooled standardized mean difference (SMD) with a 95% confidence interval (CI) was calculated using the random effects model. In addition, subgroup analysis and meta-regression analysis were performed. Eleven eligible articles containing 2,259 patients with OSA were included in this study. Pooled outcomes revealed that the NLR was significantly higher in patients with OSA than in controls (SMD 0.62, 95% CI 0.29–0.94, P = 0.002). In subgroup analyses, differences in the NLR between patients and controls increased with worsening OSA grades. Furthermore, meta-regression analysis showed that differences in mean BMI exerted a significant effect on differences in the NLR (P = 0.0003). In summary, our meta-analysis demonstrated that the NLR in OSA patients was significantly higher than that in controls, and the difference was larger in patients with severe OSA. These results indicate that the NLR may be a reliable marker for detecting systemic inflammation and predicting disease severity in patients with OSA.

[Correlation between severity of obstructive sleep apnea syndrome and red cell distribution width in elderly patients]

OBJECTIVE

To investigate the correlation between the severity of obstructive sleep apnea syndrome (OSAS) and red cell distribution width (RDW) in elderly patients.

METHODS

A cross-sectional study was conducted among 311 elderly patients diagnosed with OSAS in the snoring clinic between January, 2015 and October, 2016 and 120 healthy controls without OSAS from physical examination populations in the General Hospital of PLA. The subjects were divided into control group with apnea-hypopnea index (AHI) &lt;5 (n=120), mild OSAS group (AHI of 5.0-14.9; n=90), moderate OSAS group (AHI of 15.0-29.9; n=113) and severe OSAS group (AHI ≥ 30; n=108). The clinical characteristics and the results of polysomnography, routine blood tests and biochemical tests of the subjects were collected. Multiple linear regression analysis was used to examine the correlation between OSAS severity and RDW.

RESULTS

The levels of RDW and triglyceride were significantly higher in severe OSAS group than in the other groups (P &lt; 0.01). The levels of fasting blood glucose and body mass index were significantly higher in severe and moderate OSAS groups than in mild OSAS group and control group (P &lt; 0.05 or P &lt; 0.01). Multiple linear regression analysis showed that AHI was positively correlated with body mass index (β=0.111, P=0.032) and RDW (β=0.106, P=0.029). The area under ROC curve of RDW for predicting the severity of OSAS was 0.687 (P=0.0001).

CONCLUSIONS

The RDW increases as OSAS worsens and may serve as a potential marker for evaluating the severity of OSAS.

Modifiable Cardiovascular Risk, Hematopoiesis, and Innate Immunity

Unhealthy diet, lack of exercise, psychosocial stress, and insufficient sleep are increasingly prevalent modifiable risk factors for cardiovascular disease. Accumulating evidence indicates that these risk factors may fuel chronic inflammatory processes that are active in atherosclerosis and lead to myocardial infarction and stroke. In concert with hyperlipidemia, maladaptive immune system activities can contribute to disease progression and increase the probability of adverse events. In this review, we discuss recent insight into how the above modifiable risk factors influence innate immunity. Specifically, we focus on pathways that raise systemic myeloid cell numbers and modulate immune cell phenotypes, reviewing hematopoiesis, leukocyte trafficking, and innate immune cell accumulation in cardiovascular organs. Often, relevant mechanisms that begin with lifestyle choices and lead to cardiovascular events span multiple organ systems, including the central nervous, endocrine, metabolic, hematopoietic, immune and, finally, the cardiovascular system. We argue that deciphering such pathways provides not only support for preventive interventions but also opportunities to develop biomimetic immunomodulatory therapeutics that mitigate cardiovascular inflammation.

Nocturnal Mean Oxygen Saturation Is Associated with Secondary Polycythemia in Young Adults with Obstructive Sleep Apnea, Especially in Men

OBJECTIVE

Whether the severity of obstructive sleep apnea (OSA) contributes to clinical polycythemia is uncertain, especially in young adults. This study aimed to assess the correlation between untreated OSA and polycythemia, controlling for multiple confounders, and to observe the difference in both genders.

METHODS

All participants underwent nocturnal polysomnography. Medical comorbidities, and demographic and laboratory information were also recorded. The relationship between OSA and concomitant polycythemia in both genders was analyzed.

RESULTS

A total of 605 young participants (383 men and 222 women), aged 30.52 ± 7.21 years, were enrolled, with an average body mass index of 32.48 ± 6.06 kg/m². Although 74.4% of patients were diagnosed with OSA, less than 10% had polycythemia. The levels of hemoglobin and hematocrit increased with the severity of OSA; only men with severe OSA had significantly higher hemoglobin, hematocrit, and polycythemia compared with those in the control group (P < 0.01). Hemoglobin and hematocrit significantly correlated with mean pulse oxygen saturation (SpO₂) (P < 0.001), but the correlation coefficients were weaker in women than in men. In logistic regression analysis, mean SpO₂, but not the apnea-hypopnea index (AHI), was found to be an independent predictor of polycythemia (P < 0.05). Areas under the receive operator characteristic analysis revealed that the cutoff values of hemoglobin and hematocrit were 155.5g/L and 44.6% (P < 0.001), respectively, for assessing nocturnal hypoxemia in men with OSA.

CONCLUSION

Nocturnal mean SpO₂ was an independent predictor of polycythemia in young adults. Mean SpO₂, compared with the AHI, was more associated with polycythemia. Men were more prone to suffer from polycythemia compared with women. Hemoglobin and hematocrit values might have diagnostic utility for assessing nocturnal hypoxia severity of OSA patients, especially in men.

The association of hemocyte profile and obstructive sleep apnea

BACKGROUND

The hemocyte profile is one of the most frequently requested clinical laboratory tests. However, the analysis of blood cell indexes of obstructive sleep apnea (OSA) patients in previous studies was not comprehensive. And, this study aimed to fully analyze the blood routine in OSA patients.

METHODS

A retrospective study was conducted on 1087 male patients, who were admitted to the sleep center of Nanfang Hospital from May 2013 to February 2018. According to the apnea hypopnea index (AHI), patients were divided into four groups: control group (AHI < 5, n = 135), mild OSA (5 ≦ AHI < 15, n = 185), moderate OSA (15 ≦ AHI < 30, n = 171), and severe OSA (AHI ≧ 30, n = 596). Data collected included sleep parameters, complete blood routine, body mass index (BMI), age, and comorbidities.

RESULTS

In our study, leukocytes, neutrophils, lymphocytes, monocytes, eosinophils, basophils, erythrocytes, hemoglobin, hematocrit, platelets, MPV, and PDW-SD were statistically significant among the four groups based on AHI (P < 0.05), but no significant differences were found in MCV, RDW-SD, N/L, and P/L ratio (P > 0.05). Neutrophils, lymphocytes, monocytes, eosinophils, basophils, hemoglobin, hematocrit, platelets, and MPV were significantly correlated with AHI. Moreover, multiple linear regression analysis demonstrated that hematocrit (β = 73.254, P = 0.001), neutrophils (β = 1.414, P = 0.012), and lymphocytes (β = 4.228, P < 0.001) were independently associated with AHI.

CONCLUSION

Neutrophils, lymphocytes, and hematocrit were independently associated with OSA severity. And combining these three blood cell indicators could contribute to the diagnosis of OSA.