Obstructive Sleep Apnea: The Role of Gender in Prevalence, Symptoms, and Treatment Success

Impact of Gender on Symptoms and Comorbidities in Obstructive Sleep Apnea

Objective

Obstructive sleep apnea (OSA) is more common in men than in women. In this study, we aimed to address the impact of gender on symptoms and comorbidities in patients with OSA.

Materials and Methods

This cross-sectional study was conducted among 1,317 consecutive patients, who were admitted to the Sleep Apnea Clinic of the Marmara University Hospital between November 2015 and October 2018, and who completed questionnaires and a sleep study with cardiorespiratory polygraphy. OSA was defined as Apnea Hypopnea Index (AHI) ≥15/hour.

Results

In all, 1,042 patients (334 women) fulfilled the inclusion criteria. OSA was observed in 589 patients (56.5%). Women were older than men (50.2±12.5 versus 45.6±15.1 years) and had lower AHI (22.1±20.1 versus 26.8±21.9 events/h). In the OSA group, women were older (53.7±11.5 versus 47.8±12.8 years) and more obese (BMI 34.6 versus 31.8 kg/m²). Symptoms were categorized as frequent/very frequent, and women with OSA complained more about daytime fatigue (74.6% versus 63.7%), nocturia (69.7% versus 51.8%), headache in the morning (50.0% versus 28.4%), depressive mood (49.0% versus 19.5%), and restless legs symptoms (43.1% versus 17.2%), than did men (all p values <0.05). Comorbidities were observed more in women than in men (lung disease [25.4% versus 13.7%], hypertension [29.6% versus 15.0%], diabetes [20.3% versus 11.3%], and hypothyroidism [14.0 % versus 4.1%]). In regression analysis, age (OR 1.03, p<0.001), BMI (OR 1.13, p<0.001), and male sex (OR 2.08, p<0.001) were significantly predictive for OSA while history of tonsillectomy was protective (OR 0.48, p=0.033).

Conclusion

Fatigue, nocturia, headache, depressive mood, restless leg, and comorbidities were observed more in women. OSA-related symptoms develop late and/or the referral of women for diagnostic evaluation of OSA is delayed. Symptoms and comorbidities in women should be evaluated more attentively for earlier referral and diagnosis of OSA.

Body mass index and neuropsychological and emotional variables: joint contribution for the screening of sleep apnoea syndrome in obese

OBJECTIVE

Obstructive sleep apnoea (OSA) is the most common sleep disorder and its prevalence has increased with the obesity pandemic. We aimed to explore the presence of OSA in severe obesity and to evaluate the association of body mass index (BMI) with sleep architecture, cognition, emotional distress and comorbidities in OSA versus non-OSA patients.

METHODS

A sample of 61 patients performed a neuropsychological battery that included tasks of attention, memory, perceptual/visuospatial ability, vocabulary, inhibition, cognitive flexibility and distress symptomatology, before overnight polysomnography.

RESULTS

More than half of the sample had OSA. Excessive daytime sleepiness was not a prominent complaint. Sleep architecture was worse in the OSA than in the non-OSA group, and hypertension was increased with OSA, especially in the severe OSA group. A higher BMI was associated with cognitive distress and sleep variables and with type 2 diabetes. The apnoea-hypopnoea index (AHI) was correlated with gender and cognitive measurements. Cognitive complaints were associated with enhanced distress in both OSA and non-OSA patients.

DISCUSSION

OSA is considerably present in severely obese patients. The BMI was strongly associated with other important anthropometric measurements along with worsening sleep architecture and lower executive functioning, both of which may contribute to weight gain. The AHI was significantly higher in men and affected memory and maintaining sets on the Wisconsin Card Sorting Test which may represent a barrier to treatment adherence for this disorder. The substantial presence of cognitive complaints in OSA and non-OSA patients suggests the need for psychological intervention focused on adaptive coping strategies, mostly for depressive symptoms. Given the current obesity epidemic, these results support the need for routine sleep investigation in obese people, particularly in primary care settings. BMI, neuropsychological and emotional screening can provide crucial information about asymptomatic and high-risk patients who require prompt sleep intervention and obesity treatment.

Criteria for oral appliance and/or supine avoidance therapy selection based on outcome optimization and cost-effectiveness

AIM

Produce empirical support for further enhancements to a therapy selection protocol for obstructive sleep apnea (OSA) patients intolerant of positive airway pressure.

METHODS

A retrospective analysis was conducted in 101 men and 69 women patients. Two-night home sleep apnea studies were conducted at baseline and with a trial oral appliance. Twenty-minutes in-position sleep was required to compute supine and non-supine apnea-hypopnea indexes (AHI). Data analyses were applied after stratification by sex and response to oral appliance therapy (OAT), and the results used for to calculate incremental cost-effectiveness ratios (ICER).

RESULTS

Compared with men, women had significantly lower pre-treatment supine and non-supine AHI values (p < .05). OAT non-responders had higher non-supine AHIs, resulting in less positional-OSA and more cases with severe OSA (p < .05). Across the cohort, 21% had positional-OSA with a pre-treatment non-supine AHI < 5 events/h. In those who met this criterion, supine avoidance therapy (SAT) could have reduced the AHI values more than OAT by an average of 33% (p < .0001). The ICER for SAT instead of OAT in this group was negative, a condition that only occurs when one therapy is both less expensive and more effective than the other. A greater proportion of non-responders had post-OAT overall AHI ≥ 10 events/h with residual positional-OSA compared with responders (p < .0001). Combination therapy could reduce the AHI values by an average of 68%, resulting in ICER estimates five-times less than the reimbursement decision-making threshold.

CONCLUSIONS AND LIMITATIONS

Based on pre-treatment non-supine AHI values, SAT would provide a superior first-line treatment outcome as compared to OAT in 21% of patients diagnosed with OSA. SAT would also provide a cost-effective adjuvant to OAT in an additional 15% of cases. The benefit of SAT could not be determined in one-fifth of the cohort who slept exclusively supine.

Computational fluid dynamics modelling of human upper airway: A review

BACKGROUND AND OBJECTIVE

Human upper airway (HUA) has been widely investigated by many researchers covering various aspects, such as the effects of geometrical parameters on the pressure, velocity and airflow characteristics. Clinically significant obstruction can develop anywhere throughout the upper airway, leading to asphyxia and death; this is where recognition and treatment are essential and lifesaving. The availability of advanced computer, either hardware or software, and rapid development in numerical method have encouraged researchers to simulate the airflow characteristics and properties of HUA by using various patient conditions at different ranges of geometry and operating conditions. Computational fluid dynamics (CFD) has emerged as an efficient alternative tool to understand the airflow of HUA and in preparing patients to undergo surgery. The main objective of this article is to review the literature that deals with the CFD approach and modeling in analyzing HUA.

METHODS

This review article discusses the experimental and computational methods in the study of HUA. The discussion includes computational fluid dynamics approach and steps involved in the modeling used to investigate the flow characteristics of HUA. From inception to May 2020, databases of PubMed, Embase, Scopus, the Cochrane Library, BioMed Central, and Web of Science have been utilized to conduct a thorough investigation of the literature. There had been no language restrictions in publication and study design of the database searches. A total of 117 articles relevant to the topic under investigation were thoroughly and critically reviewed to give a clear information about the subject. The article summarizes the review in the form of method of studying the HUA, CFD approach in HUA, and the application of CFD for predicting HUA obstacle, including the type of CFD commercial software are used in this research area.

RESULTS

This review found that the human upper airway was well studied through the application of computational fluid dynamics, which had considerably enhanced the understanding of flow in HUA. In addition, it assisted in making strategic and reasonable decision regarding the adoption of treatment methods in clinical settings. The literature suggests that most studies were related to HUA simulation that considerably focused on the aspects of fluid dynamics. However, there is a literature gap in obtaining information on the effects of fluid-structure interaction (FSI). The application of FSI in HUA is still limited in the literature; as such, this could be a potential area for future researchers. Furthermore, majority of researchers present the findings of their work through the mechanism of airflow, such as that of velocity, pressure, and shear stress. This includes the use of Navier-Stokes equation via CFD to help visualize the actual mechanism of the airflow. The above-mentioned technique expresses the turbulent kinetic energy (TKE) in its result to demonstrate the real mechanism of the airflow. Apart from that, key result such as wall shear stress (WSS) can be revealed via turbulent kinetic energy (TKE) and turbulent energy dissipation (TED), where it can be suggestive of wall injury and collapsibility tissue to the HUA.

A review of fluid-structure interaction simulation for patients with sleep related breathing disorders with obstructive sleep

Obstructive sleep apnea is one of the most common breathing disorders. Undiagnosed sleep apnea is a hidden health crisis to the patient and it could raise the risk of heart diseases, high blood pressure, depression and diabetes. The throat muscle (i.e., tongue and soft palate) relax narrows the airway and causes the blockage of the airway in breathing. To understand this phenomenon computational fluid dynamics method has emerged as a handy tool to conduct the modeling and analysis of airflow characteristics. The comprehensive fluid-structure interaction method provides the realistic visualization of the airflow and interaction with the throat muscle. Thus, this paper reviews the scientific work related to the fluid-structure interaction (FSI) for the evaluation of obstructive sleep apnea, using computational techniques. In total 102 articles were analyzed, each article was evaluated based on the elements related with fluid-structure interaction of sleep apnea via computational techniques. In this review, the significance of FSI for the evaluation of obstructive sleep apnea has been critically examined. Then the flow properties, boundary conditions and validation of the model are given due consideration to present a broad perspective of CFD being applied to study sleep apnea. Finally, the challenges of FSI simulation methods are also highlighted in this article.