Obstructive sleep apnoea-hypopnoea syndrome: state of the art

Association between pollinosis and obstructive sleep apnea hypopnea syndrome in the US population: evidence from the NHANES database 2005-2018

BACKGROUND

Rhinobyon and inflammation associated with pollinosis may elevate the risk of obstructive sleep apnea hypopnea syndrome (OSAHS). However, the exact nature of this association remains unclear, particularly in large-scale populations. This study aimed to examine the relationship between pollinosis and OSAHS using data from the National Health and Nutrition Examination Survey (NHANES).

METHODS

Data from the NHANES spanning 2005 to 2018 were analyzed. Three multivariate generalized linear models (GLMs) were employed to explore the relationship between pollinosis and OSAHS: one unadjusted model, one minimally adjusted model, and one fully adjusted model. Stratified analyses were conducted to assess the impact of pollinosis and other covariates on OSAHS. Additionally, the study incorporated K-Nearest Neighbors (KNN) and smoothed curves to refine the analysis.

RESULTS

The study identified significant demographic differences between groups in factors such as pollinosis, age, gender, weight (WT), body mass index (BMI), waist circumference (WC), protein, and fat. In three adjusted models, a consistent association was observed between pollinosis and OSAHS. Specifically, Model 1 showed an odds ratio (OR) of 1.31 [95% confidence interval (CI): 1.16-1.48, P < 0.001], Model 2 revealed an OR of 1.35 (95% CI: 1.19-1.54, P < 0.001), and Model 3 indicated an OR of 1.29 (95% CI: 1.10-1.50, P = 0.002), suggesting that the relationship between pollinosis and OSAHS remained robust despite the inclusion of other covariates. Risk stratification confirmed that pollinosis was a risk factor for OSAHS (OR = 1.28, 95% CI: 1.10-1.50, P = 0.002). The KNN model further supported the utility of pollinosis as a diagnostic marker for OSAHS. Smoothing curves also demonstrated a positive correlation between pollinosis prevalence and OSAHS incidence.

CONCLUSION

This study established pollinosis as a risk factor for OSAHS, emphasizing the need for vigilance in monitoring and managing OSAHS in individuals with pollinosis risk.

The role of microsleeps to estimate sleepiness at the wheel and near-miss accidents in obstructive sleep apnea

STUDY OBJECTIVES

Obstructive sleep apnea is considered a risk factor for sleepiness at the wheel and near-miss accidents (NMA). To date, there are subjective and objective methods such as the Maintenance of Wakefulness Test (MWT) to investigate sleepiness. However, these methods have limitations. Therefore, a new analysis of the MWT was introduced based on the identification of microsleeps (MS). So, we tested MS analysis to improve the discriminative ability of MWT in recognizing individuals at risk for sleepiness at the wheel and NMA in a population with obstructive sleep apnea.

METHODS

The study was conducted on 100 naïve patients with suspected obstructive sleep apnea referred to our Sleep Medicine Unit. All patients performed a full standard polysomnography and MWT. The MWT was analyzed according to standard criteria, and the presence of MS episodes, the mean MS latency, and the MS density (the mean absolute or relative number of MS) were assessed.

RESULTS

MS were observed in 100% of alert or sleepy patients and 47% of the fully alert patients (P < .0001). Almost 90% of patients reporting NMA showed episodes of MS during MWT. The occurrence of NMA was related to excessive daytime sleepiness, MS latency, and MS density (P < .001). The discriminative power for the NMA of MS density measures was higher than that derived from latency analysis, particularly in patients without excessive daytime sleepiness and with a simultaneous mean sleep latency > 33 minutes.

CONCLUSIONS

MS analysis provides objective evidence of sleepiness and, therefore, could improve the discriminative ability of the MWT in recognizing individuals at high risk for accidents.

CITATION

Tondo P, Pronzato C, Risi I, et al. The role of microsleeps to estimate sleepiness at the wheel and near-miss accidents in obstructive sleep apnea. J Clin Sleep Med. 2025;21(2):287-295.

Causal associations of obstructive sleep apnea with Chronic Respiratory Diseases: a Mendelian Randomization study

PURPOSE

This study aimed to elucidate the causal relationship between Obstructive Sleep Apnea (OSA) and Chronic Respiratory Diseases (CRDs), employing Mendelian Randomization (MR) to overcome limitations inherent in observational studies.

METHODS

Utilizing a two-sample MR approach, this study analyzed genetic variants as instrumental variables to investigate the causal link between OSA and various CRDs, including chronic obstructive pulmonary disease (COPD), asthma, bronchiectasis, and idiopathic pulmonary fibrosis (IPF). Data were sourced from the FinnGen Consortium (OSA, n = 375,657) and UK Biobank, focusing on genome-wide associations between single-nucleotide polymorphisms (SNPs) and the diseases. Instrumental variables were selected based on strict criteria, and analyses included a random-effects inverse-variance weighted method supplemented by several sensitivity analyses.

RESULTS

The study suggests a protective effect of OSA against COPD (OR = 0.819, 95% CI 0.722-0.929, P-value = 0.002), which becomes non-significant after adjusting for BMI, indicating a potential mediating role of BMI in the OSA-COPD nexus. No significant causal links were found between OSA and other CRDs (asthma, IPF, bronchiectasis) or between COPD, asthma, and OSA.

CONCLUSIONS

Our findings reveal a BMI-mediated protective effect of OSA on COPD, with no causal connections identified between OSA and other CRDs. These results emphasize the complex relationship between OSA, BMI, and COPD, guiding future clinical strategies and research directions, particularly in light of the study's genetic analysis limitations.

Sleep Apnea and Heart Failure-Current State-of-The-Art

Sleep-disordered breathing (SDB), including obstructive and central sleep apnea, significantly exacerbates heart failure (HF) through adverse cardiovascular mechanisms. This review aims to synthesize existing literature to clarify the relationship between SDB and HF, focusing on the pathophysiological mechanisms, diagnostic challenges, and the effectiveness of treatment modalities like continuous positive airway pressure (CPAP) and adaptive servo-ventilation ASV. We analyzed peer-reviewed articles from 2003 to 2024 sourced from PubMed, EMBASE, Scopus, and Web of Science databases. The prevalence of SDB in HF patients is high, often underdiagnosed, and underappreciated. Management strategies, including CPAP and ASV, have been shown to mitigate symptoms and improve cardiac function. However, despite the availability of effective treatments, significant challenges in screening and diagnosis persist, affecting patient management and outcomes. DB significantly impacts HF prognosis. Enhanced screening strategies and broader utilization of therapeutic interventions like CPAP and ASV are essential to improve the management and outcomes of HF patients with concomitant SDB. Future research should focus on refining diagnostic and treatment protocols to optimize care for HF patients with SDB.

Changes of Serum Adiponectin Level in Patients with Obstructive Sleep Apnea Hypopnea Syndrome and Its Relationship with Sleep Monitoring Indexes

Objective

To observe the changes of serum adiponectin (AP) levels in patients with obstructive sleep apnea hypopnea syndrome (OSAHS) and explore the correlation between serum AP and polysomnography (PSG) parameters in patients with OSAHS.

Methods

The data of subjects who underwent PSG at the hospital between January 2021 and December 2022 were collected retrospectively and divided into simple snoring group (AHI < 5 times/h, n = 45), mild OSAHS group (5 ≤ AHI < 15 times/h, n = 63), moderate OSAHS group (15 ≤ AHI ≤ 30 times/h, n = 52), and severe OSAHS group (AHI > 30 times/h, n = 60). The general data, PSG indices, and serological indices of the subjects were collected and compared between groups. Pearson correlation analysis and partial correlation analysis were employed to examine the correlation between serum AP level and PSG parameters. Ordered logistic regression was employed to analyze the risk factors influencing the severity of OSAHS. The predictive capability of the serum AP level in determining the occurrence of OSAHS was assessed using ROC. The serum AP levels of subjects with different subtypes of PSG indicators were compared.

Results

In the simple snoring group, mild OSAHS group, moderate OSAHS group, and severe OSAHS group, there were statistically significant differences in microarousal count, MAI, AHI, times of blood oxygen decreased by ≥ 3%, L-SaO2, and TS90% among the 4 groups (P < 0.05). The level of serum AP was positively correlated with L-SaO2 and negatively correlated with the proportion of REM, microarousal count, MAI, AHI, times of blood oxygen decreased by ≥ 3%, TS90%, and LP (P < 0.05). High AHI was a risk factor affecting the severity of OSAHS (95% CI: 1.446-4.170). The AUC of serum AP level in diagnosing OSAHS was 0.906 (95% CI: 0.8601-0.9521), and when the Youden Index was 0.678, the sensitivity was 88.9%, and the specificity was 78.9% (P < 0.0001). In the population with a high microarousal count, high AHI, and high times of blood oxygen decreased by ≥ 3% and high TS90%, the serum AP level was lower than that in the low-level population (P < 0.05). In the population with high L-SaO2, the serum AP level was higher than that in low-level population (P < 0.05).

Conclusion

The level of serum AP decreased with the increase of the disease severity of patients with OSAHS and demonstrates a significant predictive capability for the occurrence of OSAHS. Monitoring the level of serum AP can effectively forecast the risk of OSAHS. Furthermore, alterations in serum AP levels are associated with both hypoxemia and a heightened frequency of arousal in patients with OSAHS.

The association of lymphocyte with hypothyroidism in obstructive sleep apnea

PURPOSE

Obstructive sleep apnea (OSA) is a common sleep-breathing disorder. Numerous investigations have found a strong inherent relationship between OSA and hypothyroidism. Studies suggest that lymphocytes may be involved in the development of hypothyroidism in patients with OSA. This study aimed to assess the association between lymphocytes and hypothyroidism in OSA patients.

PATIENTS AND METHODS

This study involved 920 patients with OSA who underwent nocturnal sleep monitoring, thyroid function testing, and routine blood tests. In patients with OSA, logistic regression analysis indicated independent predictors of hypothyroidism. The cutoff level of lymphocyte count was determined using a receiver operating characteristic (ROC) analysis to predict the occurrence of hypothyroidism in individuals with OSA.

RESULTS

This study comprised 920 OSA patients (617 males and 303 women), 879 with normal thyroid function, and 41 with hypothyroidism, with a hypothyroidism incidence of 4.46%. In the entire OSA population and male OSA patients, the number of lymphocytes was significantly higher in the hypothyroid group than in the control group (p = 0.002 and 0.020, respectively). In addition, among the OSA population younger than 60 years old and patients with mild to moderate OSA, lymphocytes were found to be considerably more in the hypothyroid group than in the euthyroid group. Lymphocyte count, ESS, and sex were all independent predictors of hypothyroidism development in OSA patients. According to ROC curve analysis, the risk of hypothyroidism increases with increasing lymphocyte count in the total patient population, with an optimal diagnostic cutoff point of 2.5 (× 10*9/L).

CONCLUSIONS

The prevalence of hypothyroidism in patients with OSA increases as the number of lymphocytes increases. Lymphocyte count can be used as an independent predictor of the occurrence of hypothyroidism, and it has a diagnostic value for OSA combined with hypothyroidism.

Mortality in obstructive sleep apnea syndrome (OSAS) and overlap syndrome (OS): The role of nocturnal hypoxemia and CPAP compliance

BACKGROUND

Obstructive sleep apnea syndrome (OSAS) and chronic obstructive pulmonary disease (COPD) are two chronic diseases that afflict many individuals worldwide with negative effects on health that may overlap in Overlap Syndrome (OS). The aim of our study was to investigate the differences in mortality between OSAS alone and OS and the risk factors involved.

METHODS

The study was conducted on patients with OSAS or OS diagnosis that completed 15-year follow-up between 2005 and 2023. Of these, the clinical, functional, sleep and survival data were registered and analysed. Risk factors were found by regression analysis.

RESULTS

501 patients (428 OSAS and 73 OS) were enrolled. Patients with OS had higher mortality than OSAS (p < 0,001). The morality risk factors for the overall population found were age >65 years (odds ratio (OR) = 10.69 (95%CI 3,85-29,69), p < 0,001) and low forced-expiratory volume in 1-s (FEV1) (OR = 10.18 (95%CI 2,32-44,68), p = 0,002). In patients with OSAS, age and nocturnal hypoxemia (NH) (OR = 2.41 (95%CI 1,07-5,41), p = 0,03) were risk factors, while adherence to nighttime positive airway pressure (PAP) reduced mortality (OR = 0,36 (95%CI 0,15-0,83), p = 0,017). Multivariate analysis confirmed age and FEV1 as risk factors in OS. Conversely, the risk factors for the overall population under 65 years were NH, which is confirmed in patients with OSAS alone (OR = 4,72 (95%CI 1,07-20,77), p = 0,04) in whom, on the other hand, PAP compliance reduced the mortality risk.

CONCLUSIONS

The study suggests that NH is a risk factor for all-cause mortality in sleep disorders by excluding the age; conversely, nighttime PAP improves the survival.

APAP Treatment Acceptance Rate and Cost-Effectiveness of Telemedicine in Patients with Obstructive Sleep Apnea: A Randomized Controlled Trial

PURPOSE

This study evaluated the treatment acceptance rate and cost-effectiveness of the telemedicine model in clinical practice for adult patients with obstructive sleep apnea (OSA).

PATIENTS AND METHODS

Patients admitted to the sleep center for snoring were randomly divided into telemedicine and control groups. Patients diagnosed with moderate-to-severe OSA using the Home Sleep Apnea Test (HSAT) were voluntarily treated with auto-adjusted positive airway pressure (APAP) therapy. The acceptance rate of the APAP treatment, cost of patient visits, time cost, and labor cost of doctors in the two groups were observed.

RESULTS

A total of 57 subjects were included, with an average age of 40.12±11.73 years, including 47 males (82.5%); 26 patients were in the telemedicine group, and 31 were in the control group. Follow-up results showed that the acceptance rate of APAP treatment was 57.7% and 54.8% in the telemedicine and control groups, respectively, with no significant difference between the two groups (p=0.829). The cost-benefit analysis showed that the telemedicine group reduced the cost of patients' medical treatment [-457.84(-551.19,1466.87)] but increased the extra intervention frequency and time outside the doctor's office. Further analysis showed that male subjects of older age, higher education level, distant residence, no fatty liver, poor sleep quality, severe insomnia, and higher OSA severity were more likely to receive telemedicine diagnosis and treatment.

CONCLUSION

The APAP treatment acceptance rate and compliance of OSA patients in the telemedicine group were similar to those in the control group, and the cost of patients' medical treatment was reduced. However, telemedicine increases the frequency and duration of additional out-of-hospital interventions.

A consumer wearable device for tracking sleep respiratory events

PURPOSE

The diagnosis of obstructive sleep apnea (OSA) is instrument, operator, and time-dependent and therefore requires long waiting times. In recent decades, technological development has produced useful devices to monitor the health status of the population, including sleep. Therefore, the aim of this study was to evaluate a wearable device (WD) in a group of individuals at high risk of OSA.

METHODS

The study was conducted on consecutive subjects with high risk of OSA assessed by sleep questionnaires and clinical evaluation. All subjects performed cardio-respiratory monitoring (CRM) and WD simultaneously on a single night, after which the parameters of the two sleep investigations were compared.

RESULTS

Of 20 individuals enrolled, 60% were men and mean age was 57.3 ± 10.7 years. The apnea-hypopnea index (AHI) for the CRM was 23.1 ± 19.6 events·h-1 while it was 10.3 ± 8.3 events·h-1 for the WD. Correlation analysis between the results of the two investigations showed r = 0.19 (p = 0.40) for AHI and r = 0.4076 (p = 0.07) for sO2%. The accuracy for different stages of OSA severity was 70% in OSA cases and 60% in moderate to severe cases with sensitivity and specificity varying a great deal.

CONCLUSION

Small and low-cost devices may prove to be a valuable resource to reduce costs and waiting times for a sleep investigation in suspected OSA. However, diagnosis of sleep apnea requires valid and reliable instruments, so validation tests are necessary before a device can be commercialized.

Obstructive Sleep Apnea: A Look towards Micro-RNAs as Biomarkers of the Future

Sleep-disordered breathing (SDB) includes a broad spectrum of diseases, of which obstructive sleep apnea syndrome (OSA) is the most clinically significant manifestation. OSA is a respiratory disorder characterized by episodes of complete or partial obstruction of the upper airways that disturb ventilation and sleep architecture. In recent years, interest in the clinical implications of OSA seems to have increased, probably due to the numerous studies that have shown the existence of an important correlation between OSA and cardiovascular, dysmetabolic, and neoplastic changes. The guidelines currently available highlight the importance of diagnosis and effective treatment for OSA, underlining the need for new biomarkers that are useful in clinical practice, feasible, and reproducible to guide medical decision making. In this review, we intend to provide an overview of the potential role of microRNAs as new indicators for OSA management. MicroRNAs (miRNAs) are small non-coding RNA molecules that play an important role in RNA silencing and regulation of gene expression at the post-transcriptional level. These can bind specifically to their target genes by forming silencing complexes, thus inducing degradation or altered gene expression. A wide range of miRNAs have been extensively studied in a variety of diseases including cancer, and recently, miRNAs have been shown to have enormous potential to function as diagnostic and clinical biomarkers of disease. This review includes recent studies that establish the inevitable role of miRNAs in the pathogenesis of OSA.

Clinical Evaluation and Management of Overlap Syndrome (OS) and Obesity Hypoventilation Syndrome (OHS)

Background and Aim: Sleep-disordered breathing (SDB) is an extremely common disorder with a high impact on morbidity and mortality. The purpose of this study was to compare overlap syndrome (OS) and obesity hypoventilation syndrome (OHS) and to highlight and understand the differences between them. Material and Methods: The study was conducted retrospectively on 132 subjects selected by consecutive sampling from those attending our unit for suspected SDB. After clinical evaluation as well as functional and sleep investigations, the population was divided according to diagnosis in OS and OHS; then, the clinical parameters of two groups were compared with different statistical analysis. Results: The subjects with OHS were younger and reported higher rated daytime sleepiness (p = 0.005). In addition, they presented more nocturnal respiratory events (apnea-hypopnea index (AHI) 63.61 ± 22.79 events·h−1 vs. AHIOS 42.21 ± 22.91 events·h−1, p < 0.0001) at the sleep investigation as worse gas exchange during sleep leading to a higher percentage of nocturnal hypoxemia (p < 0.0001). In contrast, subjects with OS had more an impaired respiratory function. With regard to night-time ventilatory therapy, more subjects with OS were effectively treated with continuous positive airway pressure (CPAP) (p = 0.011), while more OHS were treated with auto-adjusting PAP (APAP) (14% vs. 1%, p = 0.008). Conclusions: The present study tried to establish a framework for OS and OHS because proper management of the two disorders would reduce their burden on healthcare.

The Burden of Respiratory Alterations during Sleep on Comorbidities in Obstructive Sleep Apnoea (OSA)

BACKGROUND

Obstructive sleep apnoea (OSA) has an important impact on the risk of morbidity and mortality, so we have designed the present study to understand which factor is most involved in the risk of developing a comorbidity between OSA severity and nocturnal hypoxemia.

METHODS

A retrospective study was conducted on 617 adult subjects who were referred to our unit for a suspicion of OSA between January 2018 and January 2020.

RESULTS

Sleep investigations performed by participants (72% male and obese in 70% of cases) reported an overall mean apnoea-hypopnoea index (AHI) of 44.0 ± 24.8 events·h-1. Overall, 66% were classified as severe OSA and 76% experienced nocturnal hypoxemia. By analysing the burden of OSA severity and nocturnal hypoxemia on the comorbidities risk, multivariate analysis highlighted the predominant role of age and obesity. Accordingly, after the exclusion of the older and obese participants from the analyses, we noticed that severe OSA was related to the risk of hypertension (odds ratio (OR) = 3.0 [95% confidence interval [CI] 1.4-6.2], p = 0.004) as well as nocturnal hypoxemia (OR = 2.6 [95% CI 1.2-5.4], p = 0.01).

CONCLUSIONS

The study seems to suggest that in young, non-obese subjects, OSA is a predisposing factor for the risk of developing hypertension.

EVs-miRNA: The New Molecular Markers for Chronic Respiratory Diseases

Idiopathic pulmonary fibrosis (IPF), chronic obstructive pulmonary disease (COPD), asthma and sleep disorders are chronic respiratory diseases that affect the airways, compromising lung function over time. These diseases affect hundreds of millions of people around the world and their frequency seems to be increasing every year. Extracellular vesicles (EVs) are small-sized vesicles released by every cell in the body. They are present in most body fluids and contain various biomolecules including proteins, lipids, mRNA and non-coding RNA (micro-RNA). The EVs can release their cargo, specifically micro-RNAs (miRNAs), to both neighboring and/or distal cells, playing a fundamental role in cell-cell communication. Recent studies have shown their possible role in the pathogenesis of various chronic respiratory diseases. The expression of miRNAs and, in particular, of miRNAs contained within the extracellular vesicles seems to be a good starting point in order to identify new potential biomarkers of disease, allowing a non-invasive clinical diagnosis. In this review we summarize some studies, present in the literature, about the functions of extracellular vesicles and miRNAs contained in extracellular vesicles in chronic respiratory diseases and we discuss the potential clinical applications of EVs and EVs-miRNAs for their possible use such as future biomarkers.

Investigation of the frequency of obstructive sleep apnoea syndrome in patients with subclinical hypothyroidism

Background

The aim of this study is to determine the frequency of obstructive sleep apnoea syndrome (OSAS) in a study group with the diagnosis of subclinical hypothyroidism and in a control group without the diagnosis of subclinical hypothyroidism. This study compares these two groups in terms of demographic characteristics, chronic diseases and especially polysomnographic data.

Methods

A total of 120 patients were included in this study. They consisted of 60 patients with newly diagnosed subclinical hypothyroidism and a control group of 60 patients with normal thyroid functions. Demographic, anthropometric, polysomnography data and Epworth Sleepiness Scale scores of the patients were recorded and compared.

Results

Any significant difference in the frequency and severity of OSAS was not detected. A significant difference was found in the oxygen desaturation index (ODI), the apnoea-hypopnoea index (AHI) in rapid eye movement sleep, the AHI in supine sleep position and the arousal index of the group experiencing subclinical hypothyroidism with OSAS.

Conclusion

This study showed that there was no increase in OSAS frequency in patients with subclinical hypothyroidism, but it demonstrated that the ODI and the arousal index were significantly increased in OSAS patients diagnosed with subclinical hypothyroidism. It is thought that the diagnosis and treatment of OSAS in these patients may be important in preventing cardiovascular complications.

Manuscript Title: A 4-miRNAs Serum Panel for Obstructive Sleep Apnea Syndrome Screening

BACKGROUND

Obstructive sleep apnea syndrome (OSAS) is a common chronic sleep disorder. OSAS is closely related to cardiovascular disease, metabolic disorders, cancer risk, and sudden death. This association has special significance in young people. Although it is known that OSAS has a great impact on physical health, it is estimated that 70-80% of patients with moderate-to-severe OSAS remain undiagnosed. Therefore, a new method for early diagnosis of the disease, the therapeutic effect of OSAS and prevention of complications to important.

METHODS

A total of 110 patients with moderate-to-severe OSAS diagnosed in the Sleep Disorders Diagnosis and Treatment Center of Peking University Shenzhen Hospital were selected. After excluding other diseases, 59 patients were finally selected as the OSAS group. In addition, 60 healthy people were selected as the control group. Serum RNA was then extracted. Eight RNA samples were randomly selected from the two groups for high-throughput miRNA sequencing. The 10 miRNAs with the greatest differences were selected as preselected markers from the results. Then, qRT-PCR was performed on the remaining RNA samples of the two groups to extract and verify the 10 miRNAs, and statistical analysis was performed between groups.

RESULTS

A diagnostic panel was constructed by a stepwise logistic regression model combined with the expression data of miRNAs in the validation phase. A four-miRNA panel was identified to better predict OSAS, and the model was calculated using the following formula: Logit (P)= 0.77-1.65 × miR-486-5p - 4.56 × miR-148a-3p + 1.79 × miR-744-5p + 1.13 × let-7d-3p. The AUC for the four-miRNA panel was 0.955 (95% CI: 0.899 to 0.985; sensitivity = 91.38%, specificity = 91.38%). Gene Ontology (GO) annotation and Kyoto encyclopedia of genes and genomes (KEGG) pathway analysis was included in bioinformatic analysis.

CONCLUSION

A 4-miRNAs panel as a diagnostic biomarker for OSAS screening is feasible.