Unique sleep-stage transitions determined by obstructive sleep apnea severity, age and gender

Influence of Lingual Tonsillar Volume in Patients with Obstructive Sleep Apnea

This study aimed to evaluate the influence of lingual tonsil (LT) volume measured using a three-dimensional (3D) reconstruction volume rendering program on clinical parameters and polysomnography (PSG) results. A total of 100 patients who underwent PSG, computed tomography (CT), and allergy test from April 2016 to April 2020 were randomly selected. LT volume was measured using an imaging software program that enables 3D reconstruction of CT images. PSG parameters were analyzed by dividing the subjects into two groups according to LT volume (each 50 people). Based on the medial volume of 0.863 cm³, the upper half LT volume group and the lower half LT volume group were analyzed. Clinical factors such as body weight, neck circumference, body mass index (BMI), and age showed no difference between the two groups. Among PSG parameters, supine arousal index and non-rapid eye movement (NREM) arousal index were significantly higher in the upper half LT volume group (p = 0.012, 0.037). However, there was no significant difference in apnea-hypopnea index (AHI) between the upper and lower half LT volume groups (p = 0.749). Arousal snoring index and REM arousal index also showed no difference between the two groups. The prevalence of allergic rhinitis was not different in the two groups. High LT volume is associated with NREM arousal and arousal in the supine position, but it is not related to AHI.

Sleep apnea plays a more important role on sleep N3 stage than chronic tinnitus in adults

Sleep apnea is negatively associated with N3 sleep in children. However, the association between tinnitus and sleep N3 stage was still inconclusive. We aimed to clarify the relationship between sleep apnea, chronic tinnitus, and sleep N3 stage in adults. Clinical and overnight polysomnography data of 2847 adults were collected retrospectively. Univariate and multivariate linear regression was used to test the impacts of sleep apnea indices and chronic tinnitus on the percentage of sleep N3 stage in all adults. Univariate linear regression analysis showed that sleep apnea indices, chronic tinnitus, age, sex, hypertension, diabetes mellitus, dyslipidemia, subjective insomnia, sleep efficiency, and rapid eye movement sleep were significantly associated with sleep N3 stage. However, multivariate linear regression showed that apnea-hyponea index, but not chronic tinnitus, has a significant negative association with the percentage of sleep N3 stage. Sleep apnea plays a more important role on sleep N3 stage than chronic tinnitus in adults.

Association between early stage N2 sleep spindle burst characteristics and vigilance groups: an observational study on patients from a tertiary sleep centre

OBJECTIVE

Obstructive Sleep Apnoea (OSA) is associated with impaired vigilance. This paper examines the hypothesis that sleep spindle (Sp) characteristics during nocturnal sleep can be mapped to vigilance deficits measured by the Psychomotor Vigilance Task (PVT) in patients with OSA.

APPROACH

The PVT was performed prior to In-laboratory Polysomnography for 250 patients. PVT outcomes were clustered into three Vigilance Groups (VGs). Spindles were scored manually for a Training Cohort of 55 patients, (9491 Sps) across different blocks of NREM sleep (SBs) and validated in a Test Cohort (25 patients, 4867 Sps). We proposed a novel set of Sp features including a Spindle Burst Index (SBI), which quantifies the burst characteristics of spindles and constructed models mapping them to VGs. We also explored the performance of conventional Sp features (such as Sp number and density) in our modelling approach.

MAIN RESULTS

In the Training Cohort, we observed statistically significant differences in the SBI across VGs and SBs independent of OSA severity (1st Stage N2 SBI; p=<0.001 across VGs). In the Test Cohort, a Model based on the proposed SBI predicted VG membership with 88% accuracy. A model based on conventional Sp features mapped to VGs with 70.7% accuracy, and a model using mixed burst and conventional features reached an accuracy of 88%.

SIGNIFICANCE

Spindle features measured during diagnostic In-laboratory PSG can be mapped to PVT outcomes. The novel SBI proved useful for exploring the relationship between PVT outcomes and sleep. Further studies in larger populations are needed to verify these conclusions.

Effect of Continuous Positive Airway Pressure on Chronic Cough in Patients with Obstructive Sleep Apnea and Concomitant Gastroesophageal Reflux

BACKGROUND

Obstructive sleep apnea (OSA) and/or gastroesophageal reflux (GER) may be the contributors to chronic cough in patients with OSA and concomitant GER. This study aimed to explore whether continuous positive airway pressure (CPAP), antireflux treatment and lifestyle modifications improve chronic cough in patients with OSA and concomitant GER.

METHODS

Patients with OSA and concomitant GER who also experienced chronic cough were enrolled, and were divided into two groups. Patients who were treated with general treatment (antireflux treatment and lifestyle modifications) as the control group, and patients who were treated with CPAP and general treatment as the treatment group. Effects of different treatments on chronic cough were assessed, and the association among chronic cough, GER and OSA was evaluated by Pearson's correlation analysis.

RESULTS

The Pittsburgh Sleep Quality Index and Epworth Sleepiness Scale were better in the treatment group after 1 week of treatment; further, the improvement became stronger with the duration of therapy. The gastroesophageal reflux disease questionnaire, visual analog scale (VAS) for cough, and daytime and nighttime cough symptom scores significantly improved in both groups after treatment, whereas this improvement was more significant in the treatment group. Significant associations between the apnea-hypopnea index (AHI) and VAS, weak acid reflux and VAS, and weak acid reflux and AHI were observed.

CONCLUSION

CPAP improved the symptoms of chronic cough and GER in patients with OSA and concomitant GER. AHI and weak acid reflux may be important factors affecting the therapeutic effect of chronic cough in patients with OSA and concomitant GER.

Association and Risk Factors for Obstructive Sleep Apnea and Cardiovascular Diseases: A Systematic Review

Obstructive sleep apnea (OSA) is a serious, potentially life-threatening condition. Epidemiologic studies show that sleep apnea increases cardiovascular diseases risk factors including hypertension, obesity, and diabetes mellitus. OSA is also responsible for serious illnesses such as congestive heart failure, stroke, arrhythmias, and bronchial asthma. The aim of this systematic review is to evaluate evidence for the association between OSA and cardiovascular disease morbidities and identify risk factors for the conditions. In a review of 34 studies conducted in 28 countries with a sample of 37,599 people, several comorbidities were identified in patients with severe OSA—these were: heart disease, stroke, kidney disease, asthma, COPD, acute heart failure, chronic heart failure, hyperlipidemia, thyroid disease, cerebral infarct or embolism, myocardial infarction, and psychological comorbidities including stress and depression. Important risk factors contributing to OSA included: age > 35 years; BMI ≥ 25 kg/m²; alcoholism; higher Epworth sleepiness scale (ESS); mean apnea duration; oxygen desaturation index (ODI); and nocturnal oxygen desaturation (NOD). Severe OSA (AHI ≥ 30) was significantly associated with excessive daytime sleepiness and oxygen desaturation index. The risk of OSA and associated disease morbidities can be reduced by controlling overweight/obesity, alcoholism, smoking, hypertension, diabetes mellitus, and hyperlipidemia.

Efficacy of continuous positive airway pressure on subcutaneous adipose tissue in patients with obstructive sleep apnea: a meta-analysis of randomized controlled trials

PURPOSE

It remains inconclusive whether continuous positive airway pressure (CPAP) therapy can significantly reduce subcutaneous adipose tissue (SAT) in patients with obstructive sleep apnea (OSA). This meta-analysis of randomized controlled trials (RCTs) aimed to evaluate the impact of CPAP treatment on SAT in patients with OSA.

METHODS

We searched Pubmed, Cochrane, Web of Science, and Embase for RCTs, which investigated the effectiveness of CPAP treatment in reducing SAT among patients with OSA. Following the PRISMA guidelines, we extracted information on the study and patient characteristics, and pre- and post-CPAP measures of SAT. We then calculated the overall effects using the standardized mean difference (SMD) with a 95% confidence interval (CI).

RESULTS

A total of 5 RCTs (comprising 153 patients) met inclusion criteria for the meta-analysis. We found that the SAT did not change before and after CPAP treatment in patients with OSA (SMD = - 0.02, 95% CI - 0.25 to 0.2, z = 0.19, p = 0.85). Subgroup analyses indicated that the outcome was not affected by age, CPAP therapy duration, baseline body mass index, and measure utilized.

CONCLUSION

This meta-analysis of RCTs suggests that CPAP therapy does not significantly decrease the level of SAT among patients with OSA. Further large-scale, and high-quality randomized controlled trials are needed to better address this issue.