Understanding Pathophysiological Concepts Leading to Obstructive Apnea

[Arousal characteristics in different OSAHS populations]

Objective:This study sought to explore the effect of age on arousal index in patients with OSAHS, and the significance of arousal index among different phenotypes identified through cluster analysis according to clinical symptoms and complications. Methods:A total of 607 adult patients with OSAHS who received polysomnography in the Second Affiliated Hospital of Xi'an Jiaotong University from July 2020 to July 2021 were selected. All patients registered basic human data, symptoms, complaints and complications, completed the Epworth Sleepiness Scale. We explored the distribution of several PSG parameters in different age groups, and included typical symptoms and complications into cluster analysis to explore the parameter differences in patients with different phenotypes. Results:Young patients had the lowest arousal index and arousal frequency in NREM stage, in middle-aged patients, the arousal index was relatively higher, the arousal times during NREM with oxygen desaturation were the highest. Among elderly patients, the wakefulness after sleep onset（WASO） was the longest, the arousal times in REM sleep was the lowest, and the spontaneous arousal times in NREM sleep were the highest（P<0.05）. Among the 3 types according to the cluster analysis, phenotype Ⅰwas characterised by maximally complications, excessive daytime sleepiness and obesity, while memory and attention impairment were obvious in phenotype Ⅱ. Phenotype Ⅲhad minimal complications, relatively better mental state with shorter time-course of snoring and apnea. Phenotype I differed significantly by higher severity, more severe hypoxemia, higher arousal index and longer WASO time（P<0.05）. Conclusion:the arousal index distribution varies among OSAHS patients with different age, and cluster analysis shows that patients with severe symptoms and more complications tend to have higher arousal index.

Evaluation and Management of Snoring

Snoring can be harmless (primary) or a symptom of sleep-disordered breathing (secondary) and should alert the physician to evaluate the patient for risks thereof. Phenotypes of snoring and sleep-disordered breathing (SDB) are anatomic and nonanatomic and identifying these phenotypes and their interrelationships are critical to effective therapy. Mouth breathing alerts the physician to nasal airway obstruction, signals orofacial growth changes in children, and heralds the progression of SDB. Systematic evaluation to establish phenotypes includes assessing sleep habits, comorbidities, upper airway examination, polysomnography, and drug-induced sleep endoscopy. Strategies for treatment should be personalized and precise to the phenotype(s) to achieve the most benefit.

Obese Patients Experience More Severe CSA than Non-Obese Patients

Objective: To investigate whether central sleep apnea (CSA) is associated with an increased risk of obesity. Materials and methods: From 1 January 2000 to 31 December 2015, we screened 24,363 obese patients from the 2005 longitudinal health insurance database, which is part of the Taiwan National Health Insurance Research Database. From the same database, 97,452 non-obese patients were also screened out. Age, gender, and index dates were matched. Multiple logistic regression was used to analyze the previous exposure risk of obese and CSA patients. A p-value of <0.05 was considered significant. Results: Obese patients were more likely to be exposed to CSA than non-obese patients would (AOR = 2.234, 95% CI = 1.483–4.380, p < 0.001). In addition, the closeness of the exposure time to the index time is positively correlated with the severity of obesity and has a dose–response effect (CSA exposure < 1 year, AOR = 2.386; CSA exposure ≥ 1 year and <5 years, AOR = 1.725; CSA exposure time ≥ 5 years, AOR = 1.422). The CSA exposure time of obese patients was 1.693 times that of non-obese patients. Longer exposure time is associated with more severe obesity and has a dose-response effect (CSA exposure < 1 year, AOR = 1.420; CSA exposure ≥ 1 year and <5 years, AOR = 2.240; CSA ≥ 5 years, AOR = 2.863). Conclusions: In this case-control study, patients with CSA had a significantly increased risk of obesity. Long-term exposure to CSA and obesity is more likely and has a dose-response effect.

Nocturnal Hypoxemia Rather Than Obstructive Sleep Apnea Is Associated With Decreased Red Blood Cell Deformability and Enhanced Hemolysis in Patients With Sickle Cell Disease

Background: Although obstructive sleep apnea (OSA) could act as a modulator of clinical severity in sickle cell disease (SCD), few studies focused on the associations between the two diseases.

Research Question: The aims of this study were: (1) to explore the associations between OSA, nocturnal oxyhemoglobin saturation (SpO2) and the history of several acute/chronic complications, (2) to investigate the impact of OSA and nocturnal SpO2 on several biomarkers (hematological, blood rheological, and coagulation) in patients with SCD.

Study Design and Methods: Forty-three homozygous SCD patients underwent a complete polysomnography recording followed by blood sampling.

Results: The proportion of patients suffering from nocturnal hypoxemia did not differ between those with and those without OSA. No association between OSA and clinical severity was found. Nocturnal hypoxemia was associated with a higher proportion of patients with hemolytic complications (glomerulopathy, leg ulcer, priapism, or pulmonary hypertension). In addition, nocturnal hypoxemia was accompanied by a decrease in RBC deformability, enhanced hemolysis and more severe anemia.

Interpretation: Nocturnal hypoxemia in SCD patients could be responsible for changes in RBC deformability resulting in enhanced hemolysis leading to the development of complications such as leg ulcers, priapism, pulmonary hypertension or glomerulopathy.

Clinical Trial Registration:www.ClinicalTrials.gov, identifier: NCT03753854.

Influence of Different Measurements on the Ability of P-SAP and DES-OSA Scores to Detect Severe Obstructive Sleep Apnea

BACKGROUND

Severe obstructive sleep apnea (sOSA) represents a risk factor of postoperative complications. Perioperative sleep apnea prediction (P-SAP) and DES-obstructive sleep apnea (DES-OSA) (DES being the acronym for 2 of the participating investigators and OSA for obstructive sleep apnea) scores were validated in the detection of such patients. They include the measurement of neck circumference (NC) and distance between thyroid and chin (DTC). The aim of this study was to evaluate the influence of the measurement method of NC and DTC on the ability of the 2 scores to detect sOSA.

METHODS

A total of 371 preoperative patients were enrolled. For each of them, 6 combinations of P-SAP and DES-OSA scores were evaluated. We compared the results of the 6 combinations with the data extracted from the polysomnography (PSG) if available. The ability of the score to detect sOSA patients was evaluated using sensitivity (Se), specificity (Sp), Youden index (YI), area under receiver operating characteristic curve (AUROC), the Probit model, and the Kappa coefficient of Cohen. A P < .05 was considered as significant, a Bonferroni correction was applied if needed.

RESULTS

Three hundred and seventy-one patients had a PSG. The Se and the Sp of the DES-OSA score, and the Sp of the P-SAP score, in their ability to detect severe OSA patients, were influenced by the measurement method of the DTC and of the NC. Nevertheless, the AUROC, the Youden index, the Probit model, and the Kappa coefficient of Cohen are not influenced by the variability of measurement.

CONCLUSIONS

This study highlights that the measurement method of NC and DTC can influence the results of the 2 scores. We conclude that a strict protocol for the measurement of NC and DTC should be applied (DTC measurement should be performed on a patient with a head in neutral position and the NC measurement should be performed at the cricoid level).

Decreased serum betatrophin may correlate with the improvement of obstructive sleep apnea after Roux-en-Y Gastric Bypass surgery

Obesity is strongly correlated with obstructive sleep apnea (OSA), and bariatric surgery can effectively treat obesity and alleviate OSA. However, the contributing factors are still unclear. We aimed to explore the relationship between betatrophin and OSA in patients undergoing Roux-en-Y gastric bypass (RYGB) surgery. Our study consisted of thirty-seven individuals with OSA and type 2 diabetes (16 males, 21 females) undergoing RYGB surgery. The polysomnography test, anthropometric results, serum betatrophin, and abdominal magnetic resonance images were evaluated both before and 1 year after RYGB surgery. Factors that may correlate with the alleviation of OSA were investigated. In our study, RYGB surgery significantly decreased apnea hypopnea index (AHI) and serum betatrophin concentration (p < 0.001). The abdominal visceral fat area, subcutaneous fat area and HOMA-IR were also significantly decreased (p < 0.001). The preoperative AHI, postoperative AHI and the change in AHI were significantly correlated with the preoperative betatrophin, postoperative betatrophin and the change in betatrophin, respectively (p < 0.05). These correlations were still significant after adjustment for other risk factors. The change in betatrophin was also independently associated with the change in minimum oxygen saturation (p < 0.001). Our data might indicate that serum betatrophin was significantly independently correlated with the improvement of OSA after bariatric surgery.

The correlation between drug-induced sleep endoscopy findings and severity of obstructive sleep apnea

OBJECTIVE

This study aimed to assess the relationship between anthropometric data, drug-induced sleep endoscopy (DISE) findings, and severity of obstructive sleep apnea (OSA).

METHODS

From August 2016 to August 2017, a total of 147 surgically naïve adult patients with OSA underwent DISE. Factors that were analyzed included anthropometric data and DISE findings.

RESULTS

When anthropometric data and DISE findings were analyzed with AHI by univariate analysis, the results showed that Epworth Sleepiness Scale (ESS), body mass index (BMI), neck circumference, concentric collapse of the velum, lateral oropharyngeal collapse, and anterior-posterior collapse of the tongue base were considered potentially independent predictors (p = 0.024, p < 0 .001, p < 0 .001, p < 0.001, p < 0.001, p < 0 .001, respectively, by Spearman correlation). When all important factors were evaluated in a stepwise multiple linear regression analysis, BMI, lateral oropharyngeal collapse, and anterior-posterior collapse of the tongue base were identified as significant predictors for the severity of OSA. The final model was listed as below: AHI score = 2.19 BMI + 7.56 Oropharynx/Lateral degree + 8.23 Tongue base/ Anterior-Posterior degree - 40.59.

CONCLUSION

By analyzing anthropometric data and DISE findings with AHI score, the results indicated that BMI, lateral oropharyngeal collapse, and anterior-posterior collapse of the tongue base were important factors associated with the severity of OSA.

Sleep problems in Korean children with Down syndrome and parental quality of life

BACKGROUND

Sleep problems are common among children with Down syndrome (DS), and they can have a serious impact on children with DS as well as their parents and other family members. Specific aims of this study were to evaluate parent-reported sleep problems in children with DS and to examine the relationship between the sleep behaviour of children with DS and their parents' quality of life (QOL).

METHOD

A cross-sectional survey was conducted in September and October of 2017. Parents of children with DS were recruited from an online self-support community for parents of children with DS in South Korea. The mean age of the parents and children with DS was 40.40 years (SD = 5.09) and 7.89 years (SD = 3.03), respectively. Children's sleep problems and parents' QOL were assessed using the Children's Sleep Habits Questionnaire and the abbreviated version of the World Health Organization Quality of Life scale, respectively.

RESULTS

Results revealed that 83% of the parents reported that their child with DS experienced sleep problems. Children with DS had significantly more bedtime resistance, night waking, parasomnias and sleep-disordered breathing than did typically developing children. In addition, their Children's Sleep Habits Questionnaire scores were higher than those of typically developing children. Moreover, being older, being male and having more severe developmental delays were significant risk factors for sleep problems among children with DS. Furthermore, sleep problems in children with DS negatively affected parents' QOL.

CONCLUSIONS

Sleep problems negatively affect children with DS as well as their parents; therefore, health care providers should be aware of these issues and help parents manage sleep problems proactively.

Weight Management in Obstructive Sleep Apnea: Medical and Surgical Options

Obesity plays a pivotal role in the pathogenesis of obstructive sleep apnea (OSA) and as an exacerbating factor of OSA. Given the interlinking relationship of obesity and OSA, treatment of obesity is fundamental in the management of OSA. Weight loss of 7% to 11% significantly improves OSA with remission seen with greater weight loss. Weight loss also ameliorates the constellation of other obesity-related metabolic conditions, reducing the overall cardiovascular risk in an obese person with OSA. This article discusses specific weight loss interventions effective in improving OSA, including lifestyle interventions with dietary modification and physical activity, pharmacotherapy, and bariatric surgery.