Clinical assessment and polysomnographic study of sleep apnea in a Chinese population of snorers

Effect of nocturia in patients with different severity of obstructive sleep apnea on polysomnography: A retrospective observational study

Objective

Obstructive sleep apnea (OSA) is one of the etiologies of nocturia. We analyzed polysomnography (PSG) results to determine correlated factors related to nocturia in OSA patients with different severity.

Methods

Patients with suspected OSA were examined using PSG. They were divided into two groups based on the presence of nocturia. Nocturia was defined as a patient who needed to void at least once. Apnea-hypopnea index (AHI) was employed to classify patients according to degrees of severity: AHI<5 events/h, 5 events/h≤AHI<15 events/h, 15 events/h≤AHI<30 events/h, and AHI≥30 events/h, defined as normal, mild OSA, moderate OSA, and severe OSA, respectively. Demographic variables, PSG parameters, International Prostate Symptom Scores (IPSSs), and quality of life scores due to urinary symptoms were analyzed.

Results

In total 140 patients, 114 patients had OSA (48 had mild OSA; 34 had moderate OSA; and 32 had severe OSA) and 107 patients had nocturia. The total IPSS was significantly higher in nocturia patients in all groups except the group of severe OSA patients. With the increasing severity of OSA, more correlated factors related to nocturia were determined. In mild OSA patients, nocturia related to increased age (p=0.025), minimum arterial blood oxygenation saturation (p=0.046), and decreased AHI of non-rapid eye movement (p=0.047), AHI of total sleep time (p=0.010), and desaturation index (p=0.012). In moderate OSA patients, nocturia related to increased age (p<0.001), awake time (p=0.025), stage 1 sleep (p=0.033), and sleep latency (p=0.033), and decreased height (p=0.044), weight (p=0.025), and sleep efficiency (p=0.003). In severe OSA patients, nocturia related to increased weight (p=0.011), body mass index (p=0.009), awake time (p=0.008), stage 1 sleep (p=0.040), arousal number (p=0.030), arousal index (p=0.013), periodic limb movement number (p=0.013), and periodic limb movement index (p=0.004), and decreased baseline arterial blood oxygenation saturation (p=0.046).

Conclusion

Our study revealed that there were more correlated factors related to nocturia with increasing severity of OSA. This study helps in clinical education and treatment for OSA patients with different severity.

Modified STOP-bang questionnaire incorporating morning dry mouth and BMI adjustment in China: a retrospective study of 590 patients

BACKGROUND

Morning dry mouth (MDM) is a common symptom of Obstructive Sleep Apnea (OSA) yet current OSA screening tools overlook it.

OBJECTIVE

To enhance the specificity of the Stop-Bang questionnaire (SBQ) by adding an MDM symptom.

METHOD

A retrospective analysis on 590 patients from Peking University First Hospital (2013-2018) suspected of OSA was conducted. They underwent polysomnography. The research incorporated the MDM symptom into SBQ and adjusted the body mass index (BMI) threshold to 28 kg/m2. Predictive parameters were then calculated.

RESULTS

83.1% patients were diagnosed with OSA, with 61.4% reporting MDM. Multivariate regression confirmed MDM significantly influenced Apnea-Hypopnea Index (AHI). Adjusted SBQ with MDM showed a slight decrease in sensitivity but improved specificity, especially when using a BMI threshold of > 28 kg/m2. For AHI ≥ 5 events/h and AHI ≥ 15 events/h, adjusted SBQ with MDM (BMI >28 kg/m2) obtained the highest Youden index.

CONCLUSION

Incorporating the MDM symptom into SBQ and adjusting the BMI threshold enhances the diagnostic specificity for OSA.

A Prediction Nomogram for Severe Obstructive Sleep Apnea in Snoring Patients: A Retrospective Study

Purpose

Snoring patients, as a high-risk group for OSA, are prone to the combination of severe OSA and face serious health threats. The aim of our study was to develop and validate a nomogram to predict the occurrence of severe OSA in snorers, in order to improve the diagnosis rate and treatment rate in this population.

Patients and Methods

A training cohort of 464 snoring patients treated at our institution from May 2021 to October 2022 was divided into severe OSA and non-severe OSA groups. Univariate and multivariate logistic regression were used to identify potential predictors of severe OSA, and a nomogram model was constructed. An external hospital cohort of 210 patients was utilized as an external validation cohort to test the model. Area under the receiver operating characteristic curve, calibration curve, and decision curve analyses were used to assess the discriminatory power, calibration, and clinical utility of the nomogram, respectively.

Results

Multivariate logistic regression demonstrated that body mass index, Epworth Sleepiness Scale total score, smoking history, morning dry mouth, dream recall, and hypertension were independent predictors of severe OSA. The area under the curve (AUC) of the nomogram constructed from the above six factors is 0.820 (95% CI: 0.782-0.857). The Hosmer-Lemeshow test showed that the model had a good fit (P = 0.972). Both the calibration curve and decision curve of the nomogram demonstrated the corresponding dominance. Moreover, external validation further confirmed the reliability of the predicted nomograms (AUC=0.805, 95% CI: 0.748-0.862).

Conclusion

A nomogram predicting the occurrence of severe OSA in snoring patients was constructed and validated with external data for the first time, and the findings all confirmed the validity of the model. This may help to improve existing clinical decision making, especially at institutions that do not yet have devices for diagnosing OSA.

Development and Validation of a Prognostic Model to Predict High-Risk Patients for Coronary Heart Disease in Snorers With Uncontrolled Hypertension

Purpose

Snoring or obstructive sleep apnea, with or without uncontrolled hypertension, is common and significantly increases the risk of coronary heart disease (CHD). The aim of this study was to develop and validate a prognostic model to predict and identify high-risk patients for CHD among snorers with uncontrolled hypertension.

Methods

Records from 1,822 snorers with uncontrolled hypertension were randomly divided into a training set (n = 1,275, 70%) and validation set (n = 547, 30%). Predictors for CHD were extracted to construct a nomogram model based on multivariate Cox regression analysis. We performed a single-split verification and 1,000 bootstraps resampling internal validation to assess the discrimination and consistency of the prediction model using area under the receiver operating characteristic curve (AUC) and calibration plots. Based on the linear predictors, a risk classifier for CHD could be set.

Results

Age, waist circumference (WC), and high- and low-density lipoprotein cholesterol (HDL-C and LDL-C) were extracted as the predictors to generate this nomogram model. The C-index was 0.720 (95% confidence interval 0.663–0.777) in the derivation cohort and 0.703 (0.630–0.776) in the validation cohort. The AUC was 0.757 (0.626–0.887), 0.739 (0.647–0.831), and 0.732 (0.665–0.799) in the training set and 0.689 (0.542–0.837), 0.701 (0.606–0.796), and 0.712 (0.615–0.808) in the validation set at 3, 5, and 8 years, respectively. The calibration plots showed acceptable consistency between the probability of CHD-free survival and the observed CHD-free survival in the training and validation sets. A total of more than 134 points in the nomogram can be used in the identification of high-risk patients for CHD among snorers with uncontrolled hypertension.

Conclusion

We developed a CHD risk prediction model in snorers with uncontrolled hypertension, which includes age, WC, HDL-C, and LDL-C, and can help clinicians with early and quick identification of patients with a high risk for CHD.

Prevalence of obstructive sleep apnea as assessed by polysomnography in psychiatric patients with sleep-related problems

PURPOSE

Patients with psychiatric disorders often complain of sleep disturbances and are frequently suspected of obstructive sleep apnea (OSA). However, data regarding sleep problems evaluated by attended polysomnography (PSG) remain limited in this population. We analyzed the results of attended PSG from psychiatric patients with sleep-related problems to determine the prevalence and features of sleep disorders among this population.

METHODS

We retrospectively investigated the attended PSG results of patients with psychiatric disorders: major depressive disorder, bipolar disorder, neurodevelopmental disorder, schizophrenia, neurocognitive disorder, anxiety disorder, somatic symptom disorder.

RESULTS

Of 264 patients, 158 men (60%), mean age was 47 ± 19.9 years. More than half of the patients with major depressive disorder (62%), bipolar disorder (70%), schizophrenia (58%), neurocognitive disorders (55%), and somatic symptom disorder (56%) had OSA. Among the psychiatric patients with OSA, 62% of these patients had moderate to severe OSA. The risk factors for OSA were snoring, male, age, and body mass index. The presence of OSA was not associated with the Pittsburgh Sleep Quality Index, Epworth Sleepiness Scale score, or benzodiazepine, antipsychotic, or antidepressant use. Other sleep disorders were insomnia (19%), central disorders of hypersomnia (8%), restless legs syndrome/periodic limb movement of sleep (8%), rapid eye movement sleep behavior disorder (7%), and central sleep apnea syndrome (3%).

CONCLUSIONS

PSG revealed that moderate to severe OSA was common in psychiatric patients with or without snoring. Subjective symptoms and psychotropics did not predict OSA. Therefore, PSG is needed to reveal sleep conditions in patients with psychiatric disorders.

Smoking history and its relationship with comorbidities in patients with obstructive sleep apnea

INTRODUCTION

Current knowledge on the correlation between smoking and comorbidities associated with obstructive sleep apnea (OSA) is limited. This study evaluated the smoking history of OSA patients and analyzed the association between smoking and OSA comorbidities.

METHODS

Retrospective analysis was performed in newly diagnosed OSA patients in our hospital, a tertiary medical center, from January 2016 to December 2019. In all, 1021 patients were enrolled and divided into two groups, non-smokers (n=796) and current/former smokers (n=225), in order to compare their clinical manifestations and polysomnographic results and to analyze the association between smoking and comorbidities.

RESULTS

Compared with the non-smokers, the current/former smokers had higher Epworth sleepiness scale (ESS) scores (9.3 ± 4.0 vs 8.5 ± 5.1; p<0.05), longer sleep latency (SL) [20.5 (12.3-39.3) vs 18.5 (10.0-34.0) minutes; p<0.05], and a lower nocturnal mean oxygen saturation (91.8 ± 3.6% vs 92.8 ± 3.4%; p<0.001). There was no significant difference in the apnea-hypopnea index (AHI) between the two groups. OSA patients with a history of smoking had significantly increased risk of hypertension (OR=2.09; 95% CI: 1.46- 3.01), chronic obstructive pulmonary disease (COPD) (OR=9.80; 95% CI: 4.73-20.33), gastroesophageal reflux disease (GERD) (OR=1.97; 95% CI: 1.19-3.27), and chronic pharyngitis (OR=1.83; 95% CI: 1.32-2.54).

CONCLUSIONS

No significant association was found between previous smoking history and current OSA severity. OSA patients with a history of smoking had an increased risk of hypertension, COPD, GERD, and chronic pharyngitis.

Clinical Features and Contributing Factors of Excessive Daytime Sleepiness in Chinese Obstructive Sleep Apnea Patients: The Role of Comorbid Symptoms and Polysomnographic Variables

Background

The occurrence and severity of excessive daytime sleepiness (EDS) vary considerably among obstructive sleep apnea (OSA) patients. This study was designed to investigate the characteristics of EDS and identify its contributing factors in OSA patients.

Methods

This was a cross-sectional study from a tertiary medical center in China. A total of 874 consecutive patients with newly diagnosed OSA were included. Subjective daytime sleepiness was assessed with the Epworth Sleepiness Scale (ESS). The subjects were assigned to the non-EDS group (582 patients), mild to moderate EDS group (227 patients), and severe EDS group (65 patients) according to the ESS scores. The clinical features and polysomnographic parameters were acquired and analyzed to identify the differences between groups and the determinants of EDS.

Results

The age of patients with severe EDS (49.5 ± 11.3) was slightly greater than that of patients with mild to moderate EDS (44.5 ± 10.2) (p < 0.05) and non-EDS patients (45.2 ± 12.0) (p < 0.05). Body mass index (BMI) was highest in the severe EDS group (29.1 ± 3.6 kg/m²) (p < 0.0001), intermediate in the mild to moderate EDS group (27.9 ± 3.3 kg/m²), and lower in the non-EDS group (26.8 ± 3.3 kg/m²). Logistic regression analysis showed waist circumference, memory loss, work/commute disturbances, and sleep efficiency were independently associated with mild to moderate EDS, and the microarousal index, apnea-hypopnea index (AHI), and saturation impair time below 90% were independent contributing factors of mild to moderate EDS. Meanwhile, age, neck circumference, gasping/choking, memory loss, work/commute disturbances, and sleep latency were independently associated with severe EDS, and the AHI and mean SpO₂ were independent contributing factors of severe EDS.

Conclusions

OSA patients with various severities of EDS are more obese and have more comorbid symptoms compared to patients without EDS. Sleep fragmentation, respiratory events, and nocturnal hypoxia may be predictors of EDS. Comprehensive consideration of demographic, clinical, and polysomnographic factors is required when evaluating OSA patients.

Association of allergic rhinitis with obstructive sleep apnea: A meta-analysis

BACKGROUND

The co-existence of allergic rhinitis (AR) and obstructive sleep apnea (OSA) is a common phenomenon in clinical practice. AR has long been considered a risk factor for OSA. However, the relationship is not completely clear. Therefore, we conducted a meta-analysis to evaluate the prevalence of AR in sleep-disordered breathing (SDB) /OSA and their relationship.

METHODS

A comprehensive literature search was performed in PubMed/Medline, Google Scholar, Wiley Online Library, EMBASE, and Web of Science. Data were analyzed and pooled to estimate effect size (ES) /odds ratio (OR) with 95% confidence intervals (95%CI). Heterogeneity was quantified and evaluated by chi-squared-based Q-test and I2 test, with P < .05 and I > 50% indicating evidence of heterogeneity.

RESULTS

44 studies contained 6086 participants were included in this meta-analysis. For adults, the prevalence of AR was 22.8 (95% CI, 15.0-30.6) % in SDB and 35.2 (95% CI, 25.6-44.7) % in OSA. In children with SDB and OSA, the prevalence of AR was 40.8 (95% CI, 24.3-57.2) %, and 45.2 (95% CI, 25.4-65.0) % respectively. The odds ratios of prevalence of the SDB pediatric patients with AR was 2.12 (95%CI, 1.75, 2.57; P < .0001) times higher than that of non-SDB pediatric patients. There were no significant differences between OSA adults with or without AR in BMI (Body Mass Index), neck circumference, apnea hypopnea index (AHI) and epworth sleep scale score (ESS).

CONCLUSION

The prevalence of AR in OSA/SDB is considerably high and children with SDB suffering from a higher incidence of AR than non-SDB. OSA adults accompanied with AR do not have any influences on sleep parameters.

Androgens modulate chronic intermittent hypoxia effects on brain and behavior

Sleep apnea is associated with testosterone dysregulation as well as increased risk of developing neurodegenerative diseases, such as Alzheimer's disease (AD) and Parkinson's disease (PD). A rodent model of the hypoxemic events of sleep apnea, chronic intermittent hypoxia (CIH), has been previously documented to impair cognitive function and elevate oxidative stress in male rats, while simultaneously decreasing testosterone. Therefore, androgens may modulate neuronal function under CIH. To investigate the role of androgens during CIH, male rats were assigned to one of four hormone groups: 1) gonadally intact, 2) gonadectomized (GDX), 3) GDX + testosterone (T) supplemented, or 4) GDX + dihydrotestosterone (DHT) supplemented. Each group was exposed to either normal room air or CIH exposure for one week, followed by memory and motor task assessments. Brain regions associated with AD and PD (entorhinal cortex, dorsal hippocampus, and substantia nigra) were examined for oxidative stress and inflammatory markers, key characteristics of AD and PD. Gonadally intact rats exhibited elevated oxidative stress due to CIH, but no significant memory and motor impairments. GDX increased memory impairments, regardless of CIH exposure. T preserved memory function and prevented detrimental CIH-induced changes. In contrast, DHT was not protective, as evidenced by exacerbated oxidative stress under CIH. Further, CIH induced significant spatial memory impairment in rats administered DHT. These results indicate androgens can have both neuroprotective and detrimental effects under CIH, which may have clinical relevance for men with untreated sleep apnea.

Sex differences in sleep apnea and comorbid neurodegenerative diseases

Sleep apnea is a disorder, which increasingly affects people worldwide. Whether the associated hypoxic events during sleep are central or obstructive in origin, the end result is excessive daytime sleepiness and an increased risk for several comorbidities, such as cardiovascular and neurodegenerative disorders. Sleep apnea is diagnosed more frequently in men than women, suggesting a role of sex hormones in the pathology of the disease. Furthermore, there are sex differences in the development and progression of comorbid diseases associated with sleep apnea. Therefore, treatment of sleep apnea may be clinically relevant for prevention of subsequent sex-specific comorbid disorders. While the impact sleep apnea has on cardiovascular events has been the subject of many research studies, the role of sleep apnea in neurodegeneration is less established. Here we review known risk factors for sleep apnea and the implications of the observed sex differences in this disease. We also summarize the evidence and mechanisms for how sleep apnea may contribute to the onset of neurodegenerative disorders, such as Alzheimer's disease and Parkinson's disease.

Predictive value of craniofacial and anthropometric measures in obstructive sleep apnea (OSA)

BACKGROUND

Most individuals with OSA remain undiagnosed, mainly due to limited access to effective screening tools and diagnostic facilities. Therefore, the objective of this study was to identify craniofacial and anthropometric measurements that predict OSA in an Indian population.

METHODS AND FINDINGS

Male subjects (n = 76) between 25 and 50 years of age were recruited for the study from the general population. The study measures consisted of home-based type IV polysomnography and a total of 40 anthropometric and craniofacial measurements. Key measures were identified, and a model was developed with these variables, which predicted the presence of OSA with a sensitivity, specificity and overall accuracy of 93.1, 20.0 and 74.4%, respectively.

CONCLUSION

This preliminary study shows the utility of craniofacial and anthropometric variables in the identification of individuals at risk of OSA. These findings need to be further validated against the results of overnight polysomnography in a large independent population.