Prevalence and association analysis of obstructive sleep apnea with gender and age differences - Results of SHIP-Trend

Prevalence and Risk Factors for Secondary Hypertension in Young Adults

BACKGROUND

The prevalence of secondary causes of hypertension in young adults is unknown, and therefore, there is no consensus about the indication of screening of secondary hypertension (2HTN) in this population. The objective was to report the prevalence and the causes of 2HTN in young subjects.

METHODS

In this cross-sectional study, 2090 patients with confirmed hypertension aged 18 to 40 years with full workup for 2HTN screening were included. We assessed the prevalence of 2HTN and analyzed the factors associated.

RESULTS

Among 2090 patients, 619 (29.6%) had a 2HTN. The most frequent diagnoses of 2HTN in descending order were primary aldosteronism (n=339; 54.8%), renovascular hypertension (n=114; 18.4%), primary kidney disease (n=80; 12.9%), pheochromocytoma/functional paraganglioma (n=37; 5.9%), hypertension caused by drugs or substances (n=32; 6.0%), and other diagnoses (n=17; 2.7%). Patients with blood pressure <160/100 mm Hg did not have a lower prevalence of 2HTN regardless of the number of treatments. The prevalence of 2HTN was higher in the decade between 30 and 40 years of age than between 18 and 30 years of age (P=0.024). Female sex, hypokalemia, treatment with at least 2 medications, no familial history of hypertension, body mass index <25 kg/m², and diabetes were associated with a higher prevalence of 2HTN.

CONCLUSIONS

The prevalence of 2HTN is high among young patients with hypertension (29.6% in our cohort), regardless of age and blood pressure level. All patients with hypertension under 40 years of age should be screened for secondary causes.

Evaluation and Management of Perioperative Pulmonary Complications

Pulmonary complications are very common after noncardiac surgery and can be easily overlooked. If not properly screened for or evaluated these can in many instances lead to postoperative respiratory failure or even death. Decisions regarding ambulatory versus inpatient surgery, modality of anesthesia, protective ventilation and method of weaning, type of analgesia, and postoperative monitoring can be crucial to avoid such complications.

Sex Differences in Obstructive Patterns on Drug-Induced Sleep Endoscopy

OBJECTIVE

To identify and characterize sex differences in collapse patterns on drug-induced sleep endoscopy (DISE) in patients with obstructive sleep apnea (OSA).

STUDY DESIGN

Retrospective cohort analysis.

SETTING

An outpatient tertiary care academic medical center.

METHODS

A retrospective cohort study at a single tertiary care institution was performed from 2020 to 2023. All adult patients who underwent a DISE were included in this study. Univariate and multivariate analyses were used to compare differences between males and females on DISE.

RESULTS

117 patients who underwent DISE were included in this study, including 30% females (n = 35). The average age was 54.7 years (SD 15.2), mean BMI was 28.6 kg/m2 (SD 4.1), and mean apnea-hypopnea index (AHI) was 32.3 events per hour (SD 21.3). Most patients had severe OSA (48.7%). There was no difference in palatine or lingual tonsil size between sexes. On DISE, a significantly lower proportion of females demonstrated complete oropharyngeal lateral wall collapse (25.7% females vs 51.2% males, P = .008). Multivariate analysis revealed that male sex was independently associated with the presence of complete collapse at the oropharynx (odds ratio [OR] 2.55, 95% confidence interval [CI] [0.005-1.868], P = .048) but not at other levels. Additionally, higher BMI was associated with any collapse (partial or complete) at the oropharynx (OR 1.30, 95% CI [0.131-0.392], P < .001).

CONCLUSION

This study demonstrates that a lower proportion of females have complete oropharyngeal lateral wall collapse even when controlling for BMI and AHI. Additional studies are needed to better understand the differences in OSA physiology between the sexes.

Stated patient preferences for overnight at-home diagnostic assessment of sleep disorders

PURPOSE

The diagnostic workup for assessment of sleep disorders commonly involves overnight testing to assess sleep patterns and pathological events. So far, little is known about preferences for provision of home sleep tests to patients with sleep disorders. This study aims to close this gap by eliciting preferences for home sleep testing using a discrete choice experiment (DCE).

METHODS

A DCE with seven attributes of at-home sleep testing and three levels per attribute was developed using a fractional factorial design. Patients with and without previous sleep testing experience were recruited from two large sleep centers in Germany. Coefficients for attribute levels were calculated using a conditional logit model to estimate their influence on choice decisions and calculate the relative importance of each attribute.

RESULTS

305 patients (54.5 ± 13,1 years, 65.3% male) were enrolled, and 288 surveys with complete data included for analysis. Attributes with greatest relevance were Waiting time to discuss sleep study results; Waiting time to conduct sleep study, and Sleep quality during measurement. Of lowest importance was Diagnostic accuracy of sleep study, followed by Effort to apply sleep study device. Significant heterogeneity in choice behavior was found, including differences by gender, willingness-to-pay for sleep studies, and previous experience with sleep studies. Preferred location for conducting sleep testing was at-home in 50.7% and in-lab in 46.9%.

CONCLUSIONS

Preferences and relative importance of home sleep test attributes vary among different subgroups. Considering those preferences can be important for clinicians and policymakers when designing care pathways and planning of testing policies for sleep disorders.

Exploring the link between vitamin D deficiency and obstructive sleep apnea: A comprehensive review

Despite the high prevalence and significant health burden of obstructive sleep apnea (OSA), its underlying pathophysiology remains incompletely understood. This comprehensive review explores the emerging connection between vitamin D deficiency and OSA, discusses potential mechanisms underlying this association, and explores the therapeutic implications of these findings. Recent research has consistently highlighted the high incidence of vitamin D deficiency among patients with OSA, which often occurs independently of geographical location. This suggests that factors beyond lack of sunlight exposure may be involved. This review also discusses how reduced vitamin D may be associated with more severe manifestations of OSA. In addition, it explores the potentiality of using vitamin D supplements as a therapeutic strategy for OSA, noting that some studies have found improvements in sleep quality and a reduction in OSA severity. Potential mechanisms are proposed, including the role of vitamin D deficiency in promoting inflammation, oxidative stress, hypoxia, impairing immune function, muscle function, and gene polymorphism of vitamin D receptors, all of which could contribute to the pathogenesis of obstructive sleep apnea. The paper underscores the need for future research to validate these observations, to determine optimal vitamin D supplementation dosage and duration, to explore potential side effects and risks, and to investigate potential interactions with other treatments.

Disparities in polysomnography referral in a high-risk cardiac population

PURPOSE

Obstructive sleep apnea (OSA) is associated with metabolic, cardiovascular, and cerebrovascular comorbidities. Appropriate diagnosis and treatment of OSA might mitigate these comorbidities. This retrospective review sought to assess the impact of sex, age, race, ethnicity, and insurance status on polysomnography (PSG) referral rates.

METHODS

An institutional STOP-Bang database of 299,320 patients was filtered for patients admitted to the hospital with an acute cardiac diagnosis between 2015-2020. A cohort of 4,735 patients were risk stratified by STOP-Bang (SB) score and correlations were made between PSG referrals and demographic and clinical variables (sex, age, race, ethnicity, and insurance status).

RESULTS

Of the 25.3% of the cohort with high SB scores (5-8) only 21.3% were referred for PSG. Age and female sex were negatively associated with sleep study referrals (p < 0.001). No correlation was found between sleep study referral rates and race or ethnicity. No correlation was found between sleep study referrals and insurance provider. Admitting cardiac diagnosis significantly influenced sleep study referrals with diagnoses of arrhythmias and myocardial infarction being associated with an increased rate of PSG referrals compared to heart failure patients (p < 0.002).

CONCLUSIONS

Our study found no significant correlation between PSG referral rates and race, ethnicity, or insurance provider. However, we found low overall rates of PSG referral, with negative correlations between older age and female sex and a high-risk cardiac population. This represents a substantial missed opportunity to identify patients at risk for OSA, obtain a diagnosis, and provider adequate treatment.

Undergraduate dental sleep medicine teaching at German university dental schools - a questionnaire-based survey

PURPOSE

Diagnosing and treating obstructive sleep apnea (OSA) requires fundamental understanding of sleep medicine, including training and clinical experience. So far, dental sleep medicine (DSM) has not yet become a mandatory part of dental education in Germany. This questionnaire-based survey for both lecturers and students aimed to evaluate DSM education among undergraduate students.

METHODS

A structured questionnaire was sent to the managing directors and student councils of all 30 German university dental schools. The questionnaire contained 13 questions on teaching quantity and content, lecturers' knowledge, and future interest in DSM. For each university dental school, only one questionnaire should be completed by the student council and the managing director. A scoring system assessed lecturers' knowledge based on clinical experience and qualifications. Descriptive data and correlation coefficients were calculated (P < 0.05).

RESULTS

The responses of 24 lecturers (80%) and 28 students (93.3%) could be evaluated. DSM was reported to be included in the curriculum by 14 lecturers (58.3%) and 4 students (14.3%). Mean teaching hours per semester were 1.4 ± 1.4 h (lecturers) and 0.2 ± 0.6 h (students) accordingly. Greater knowledge of lecturers in DSM was positively correlated with the inclusion of DSM in the curriculum (P = 0.022) and with the number of teaching hours per semester (P = 0.001).

CONCLUSION

Postgraduate education and incorporating DSM knowledge into undergraduate education ("Teach the Teacher") seems to play a key role in fundamentally training future dentists in this field.

Portable polygraphic device (Somnocheck micro CARDIO®) provides accurate diagnostic information in psychiatric patients at risk for obstructive sleep apnoea: an observational cohort study

BACKGROUND

Symptoms of obstructive sleep apnoea (OSA) overlap significantly with those of psychiatric disorders, making accurate diagnosis of OSA challenging within psychiatric settings. Diagnosing OSA in psychiatric patients is crucial because untreated OSA can exacerbate psychiatric symptoms, reduce treatment efficacy, and impair overall quality of life. This study aimed to determine the diagnostic accuracy of a readily accessible procedure for psychiatric patients in a real-world clinical setting by comparing the Somnocheck micro CARDIO® (SCm) portable cardiorespiratory polygraphy device with the gold standard polysomnography (PSG).

METHODS

This observational cohort study included consecutive psychiatric patients at intermediate to high risk for OSA based on screening with the STOP-Bang questionnaire, admitted to a single tertiary care centre between June 1, 2016 and December 31, 2022. The Apnoea-Hypopnoea-Index (AHI), Apnoea-Index (AI), Oxygen-Desaturation-Index (ODI), and minimum oxygen saturation were measured sequentially by SCm and PSG.

RESULTS

A total of 57 patients were analysed (median age 62.0 [Interquartile Range (IQR), 51.5-72.5] years; 34 [59.6%] men). Regarding AHI, no significant differences (AHI measured by PSG, median, 16.6 [IQR, 6.2-26.7] vs. AHI measured by SCm, median, 14.9 [IQR, 10.0-22.8]; p = 0.812; r = 0.71) were found between SCm and PSG. AI, ODI and minimum oxygen saturation differed significantly between SCm and PSG. Using optimised cut-off values (any OSA: AHISCm ≥ 9.25), SCm showed high sensitivity (0.894) and high specificity (0.800) for the diagnosis of OSA, with an area under the receiver operating characteristic curve of 0.877.

CONCLUSIONS

This study found that the SCm portable device was accurate in identifying psychiatric patients with OSA. AHI measurement by SCm provided reliable diagnostic performance in comparison with the gold standard polysomnography. These findings support the integration of polygraphic measurements into the routine sleep assessment of psychiatric patients. Early and accurate diagnosis of OSA in this population can significantly improve the management of both sleep disorders and psychiatric conditions, potentially enhancing overall treatment outcomes and quality of life for these patients.

Mandibular device treatment in obstructive sleep apnea -A structured therapy adjustment considering night-to-night variability night-to-night variability in mandibular devices

BACKGROUND

Mandibular advancement devices (MAD) are a well-established treatment option for obstructive sleep apnea (OSA). MAD are considered preferably for patients with mild to moderate OSA presenting with a elevated night-to-night variability (NNV). This study aimed to determine the treatment effect of MAD on NNV considering different protrusion distances and patient related outcome (PRO).

METHODS

We conducted a prospective cohort analysis of patients before MAD with 60% and 80% of the maximum protrusion. OSA severity was assessed using a home-sleep test for two consecutive nights. PRO contained the Epworth Sleepiness Scale (ESS) and sleep related quality of life (FOSQ).

RESULTS

Twenty patients with a median overweight body-mass-index of 27.1 (interquartile range (IQR) 16.3 kg/m²), with a mainly mild to moderate OSA with an apnea -hypopnea index (AHI) of 18.3 / h (IQR 17.7) and elevated ESS of 12.5 (IQR 8.0) were included. As opposed to 80%, 60% protrusion significantly but not 80% relevantly reduced AHI (60%%: 11.2 (IQR 5.5)/h, p = 0.01; 80%: 12.9 (IQR18,0)/h, p = 0.32) and improved the ESS (60%: 8.0 (IQR 10,0); 80%: 10 (IQR 9.0)), with therapy settings. No correlation could be detected between NNV and ESS, and FOSQ changes. Higher baseline NNV was associated with severe OSA (p = 0.02) but not with gender, overweight, or status post-tonsillectomy.

CONCLUSIONS

OSA improvement is associated with lower NNV; both OSA and NNV are connected to the degree of protrusion. Therefore, higher NNV does not justify the exclusion of candidates for MAD treatment. PRO changes are not visibly affected by NNV but by general OSA changes. These findings may help to define and optimize future study designs for the primary outcome decision between objective OSA parameters and PRO.

Age modifies the association between severe sleep apnea and all-cause mortality

PURPOSE

While sleep apnea (SA) gets more prevalent with advancing age, the impact of age on the association between SA and health outcomes is not well known. We assessed the association between the severity of SA and all-cause mortality in different age groups using large longitudinal data.

METHOD

We applied a Natural Language Processing pipeline to extract the apnea-hypopnea index (AHI) from the physicians' interpretation of sleep studies performed at the Veteran Health Administration (FY 1999-2022). We categorized the participants as no SA (n-SA, AHI< 5) and severe SA (s-SA, AHI≥30). We grouped the cohort based on age: Young≤40; Middle-aged:40-65; and Older adults≥65; and calculated the odds ratio (aOR) of mortality adjusted for age, sex, race, ethnicity, BMI, and Charlson-Comorbidity Index (CCI) using n-SA as the reference.

RESULTS

We identified 146,148 participants (age 52.23 ± 15.02; BMI 32.11 ± 6.05; male 86.7 %; White 66 %). Prevalence of s-SA increased with age. All-cause mortality was lower in s-SA compared to n-SA in the entire cohort (aOR,0.56; 95%CI: 0.54,0.58). Comparing s-SA to n-SA, the all-cause mortality rates (Young 1.86 % vs 1.49 %; Middle-aged 12.07 % vs 13.34 %; and Older adults 26.35 % vs 40.18 %) and the aOR diminished as the age increased (Young: 1.11, 95%CI: 0.93-1.32; Middle-aged: 0.64, 95%CI: 0.61-0.67; and Older adults: 0.44, 95%CI: 0.41-0.46).

CONCLUSION

The prevalence of severe SA increased while the odds of all-cause mortality compared to n-SA diminished with age. SA may exert less harmful effects on the aged population. A causality analysis is warranted to assess the relationship between SA, aging, and all-cause mortality.

The mediating effect of TyG and its derived indices in the association between OSAHS and atherosclerosis in patients with T2DM

OBJECTIVE

Triglyceride-glucose index (TyG) and its derived indices which better reflect metabolic disturbances on atherosclerosis has not been reliably compared in patients with type 2 diabetes mellitus (T2DM). Besides, obstructive sleep apnea hypopnea syndrome (OSAHS), a driver of atherosclerosis (AS), can exacerbate metabolic disturbances strongly. The aim of this study is to explore the mediating effect of glycolipid metabolism on the association between OSAHS and arterial stiffness in T2DM patients.

METHODS

154 T2DM patients were involved in this study and were split into two groups: T2DM and T2DM + AS. Logistic regression analysis determined the accurate effects of different factors on the AS of T2DM patients. The capacity of TyG and the indices it derives to predict AS was assessed using the receiver operating characteristic (ROC) curve. Mediation analysis was employed to investigate the mediating effect of TyG and its derived indices on the association between OSAHS and arterial stiffness in T2DM patients.

RESULTS

OSAHS, TyG, and its derived indices were independent risk factors for AS in T2DM patients. Stratified by age, the hazardous effects of TyG and its derived indices remained significant in T2DM patients aged ≥ 50 years, but not in those aged < 50 years. In T2DM patients aged ≥ 50 years, the novel indices have a high predictive value for AS, with TyG-BMI exhibiting the largest AUC(AUC:0.788;95% CI:0.647 ∼ 0.928; P < 0.001). The mediation analysis results indicated that in T2DM patients aged ≥ 50 years, TyG, TyG-BMI, TyG-WC, and TyG-WHtR acted as potential mediators in the association between OSAHS and AS, with mediation effects of 33.42%, 48.2%, 37.7%, and 40.21%, respectively. However, there was no significant mediating effect observed in the younger patients.

CONCLUSION

TyG and its derived indices are strongly correlated with AS in T2DM patients, of which TyG-BMI has the best predictive performance. Besides, OSAHS partially exerts its atherogenic effect through glucolipid metabolism disorder in the T2DM population aged ≥ 50 years, while it mainly exerts a direct atherogenic effect in patients aged < 50 years.

Sleep Disordered Breathing and Neurocognitive Disorders

Sleep-disordered breathing (SDB), which includes conditions such as obstructive sleep apnea (OSA) and central sleep apnea (CSA), is an independent risk factor for cerebral small vessel disease (CSVD), stroke, heart failure, arrhythmias, and other cardiovascular disorders. The influence of OSA on brain structure and cognitive function has become an essential focus in the heart-brain axis, given its potential role in developing neurocognitive abnormalities. In this review, we found that OSA plays a significant role in the cardio-neural pathway that leads to the development of cerebral small vessel disease and neurocognitive decline. Although data is still limited on this topic, understanding the critical role of OSA in the heart-brain axis could lead to the utilization of imaging modalities to simultaneously identify early signs of pathology in both organ systems based on the known OSA-driven pathological pathways that result in a disease state in both the cardiovascular and cerebrovascular systems. This narrative review aims to summarize the current link between OSA and neurocognitive disorders, cardio-neural pathophysiology, and the treatment options available for patients with OSA-related neurocognitive disorders.

Association between triglyceride glucose-body mass index and obstructive sleep apnea: a study from NHANES 2015-2018

Background

The association between TyG-BMI index and the risk of obstructive sleep apnea (OSA), a recently identified biomarker indicating insulin resistance, has yet to be elucidated. Therefore, this study aimed to investigate the association between TyG-BMI index and the risk of OSA using the NHANES database.

Methods

Analyses were performed on NHANES data conducted between 2015 and 2018. Logistic regression, stratified analyses, curve-fitting analyses, and threshold effects analyses were utilized to assess the association between TyG-BMI index and the risk of OSA.

Results

The study included 4,588 participants. Multifactorial logistic regression analyses found a significant association between TyG-BMI and increased risk of OSA [OR: 1.54 (CI:1.39-1.70)]. In stratified analyses, age interacted with the association, with TyG-BMI being associated with increased risk of OSA only in a subgroup of subjects younger than 60 years [1.31 (1.14-1.50)], but gender, smoking status, and alcohol use, did not influence the association. The presence of diabetes, hypertension, and cardiovascular diseases also modified the association, but the number of the included subjects with such conditions was significantly lower, therefore the significance of associations was not observed in those subgroups. Additionally, the risk was non-linearly associated, with the inflection point of TyG-BMI at 12.09, after which the lower slope in the risk was observed.

Conclusion

This study demonstrates that elevated levels of the TyG-BMI index are correlated with risk for OSA, underscoring the significance of these findings in facilitating early prevention or timely intervention for OSA.

Evaluation of an OSA Risk Screening Smartphone App in a General, Non-Symptomatic Population Sample (ESOSA)

Background: Obstructive Sleep apnea (OSA) is a prevalent sleep disorder, risk factor for cardiovascular disease and imposes a substantial global socioeconomic and health burden. OSA is insufficiently diagnosed as it often presents with unspecific or no symptoms. This study compares the effectiveness of a smartphone-based screening method to polysomnography (PSG) in a general, non-symptomatic population sample. Methods: Adult subjects were recruited from the general population. Subjects reporting OSA-related symptoms suggesting an increased OSA risk were excluded. Included subjects underwent Type-II PSG and a parallel breathing sound analysis using the Snorefox M smartphone app. The PSG scores were compared with the results of the Snorefox M app for its ability to detect moderate to severe OSA (AHI ≥ 15). Results: 150 subjects were included. All subjects completed the diagnostic night, no adverse events occurred. A valid analysis result was obtained for 142 subjects. A total of 24% of subjects had moderate to severe OSA based on the PSG results. The Snorefox M software app showed a sensitivity of 0.91 (0.76, 0.98), specificity of 0.83, PPV of 0.63 (0.48, 0.77), and NPV of 0.97 (0.91, 0.99) to detect AHI ≥ 15 compared with the reference PSG (95% CI). Conclusions: This study compares for the first time, the performance of an app-based OSA screening tool with PSG in a non-symptomatic population sample. Easily accessible screening tools can play a role in complementing existing diagnostic possibilities, helping to increase the diagnosis rate, with a positive effect on cardiovascular health in a relevant population share.

Gender differences in oral appliance treatment of obstructive sleep apnea

PURPOSE

Although overall success rates for treating obstructive sleep apnea (OSA) with an oral appliance (OA) are high, they are significantly higher among females. To verify published data, the study's purpose was to evaluate a participant sample after one year of OA use. The primary outcome was treatment response, with responders defined as having an apnea-hypopnea index (AHI) < 10 at follow-up and/or reduced by ≥50% of baseline. Secondary measures were from standardized questionnaires.

METHODS

A sample of 314 participants, predominately with moderate-to-severe OSA, were enrolled and instructed to use an OA every night. At baseline and one-year follow-up, polygraphic recordings and questionnaires, including sleepiness (measured using the Epworth sleepiness scale) and quality-of-life (measured using the Functional Outcomes of Sleep Questionnaire), were collected.

RESULTS

Among the 314 participants, 192 completed the one-year evaluation: 51 females (27%) and 141 males (73%). Overall, OA treatment resulted in 78% and 77% responders among females and males, respectively. Neither the difference in improvement nor the absolute change in AHI differed significantly based on gender, at any OSA severity level. There were no significant gender differences in sleepiness or quality of life. Treatment-related adverse reactions were more common among females.

CONCLUSION

Both females and males with OSA respond well to OA therapy, with nonsignificant gender differences in outcomes. Thus, the hypothesis that females respond better to OA treatment is rejected.

Bed partner perception of CPAP therapy on relationship satisfaction and intimacy-A European perspective from the ESADA network

Obstructive sleep apnea increases morbidity and mortality risks. The most common treatment is continuous positive airway pressure, with nasal mask usage being important, but not always optimal. While most research on treatment adherence focuses on the patient, the bed partner's involvement may be detrimental. Our study aim is to obtain a European-wide picture of the bed partner's attitude and support towards continuous positive airway pressure therapy, including effects on relationship satisfaction and intimacy. The English translation of a German bed partner questionnaire, assessing relationship satisfaction and three major components (general attitude, perceived mask looks, intimacy effects) was distributed within the European Sleep Apnea Database Network and translated in participating countries' local language. Data were collected for 2 years. In total, 10 European countries (13 sleep centres) participated with 1546 questionnaires. Overall, 91% of bed partners had a positive attitude towards continuous positive airway pressure therapy, 86% perceived mask looks not negative, 64% stated no negative intimacy effects. More specifically, 71% mentioned improved sleep quality, 68% supported nightly device usage. For 41% of bed partners, relationship satisfaction increased (no change for 47%). These results were significantly more pronounced in Eastern/Southern Europe compared with Middle Europe, especially regarding intimacy effects. However, increased continuous positive airway pressure therapy length affected attitude negatively. These results provide necessary information to improve treatment strategies by including educational couple-focused approaches. Among others, we revealed that negative intimacy effects are not considered a barrier to continuous positive airway pressure adherence. These results may inspire more research identifying regional gaps with need for treatment adjustments.

Links Between Obstructive Sleep Apnea and Myocardial Blood Flow Changes Impacting Adverse Cardiovascular Disease-related Outcomes

PURPOSE OF REVIEW

Recent studies have demonstrated an association between obstructive sleep apnea (OSA) and abnormal myocardial blood flow (MBF), myocardial flow reserve (MFR), and coronary microvascular dysfunction (CMD). Here, we review the evidence and describe the potential underlying mechanisms linking OSA to abnormal MBF. Examining relevant studies, we assess the impact of OSA-specific therapy, such as continuous positive airway pressure (CPAP), on MBF.

RECENT FINDINGS

Recent studies suggest an association between moderate to severe OSA and abnormal MBF/MFR. OSA promotes functional and structural abnormalities of the coronary microcirculation. OSA also promotes the uncoupling of MBF to cardiac work. In a handful of studies with small sample sizes, CPAP therapy improved MBF/MFR. Moderate to severe OSA is associated with abnormal MFR, suggesting an association with CMD. Evidence suggests that CPAP therapy improves MBF. Future studies must determine the clinical impact of improved MBF with CPAP.

Risk of Obstructive Sleep Apnea, Chronic Dizziness, and Sleep Duration

BACKGROUND

Although it is recommended that obstructive sleep apnea (OSA) be screened for using a validated self-report questionnaire in patients experiencing dizziness, there is still a lack of research on the relationship between high risk of OSA and chronic dizziness.

OBJECTIVES

The study aimed to examine the relationship between the high risk of OSA and chronic dizziness and investigate how this relationship is affected by sleep duration.

METHODS

This cross-sectional study used data from the 8th Korea National Health and Nutrition Examination Survey (2019-2021). Adults aged 40 years or older were included and divided into two groups using the STOP-Bang Questionnaire (SBQ): a high-risk group for OSA or not. Complex samples logistic regression analyses were performed to examine the odds ratios of chronic dizziness based on the national population estimates.

RESULTS

Our findings showed that individuals in the high-risk group for OSA were significantly more likely to experience chronic dizziness. Specifically, among subgroups based on sleep duration, the high-risk group for OSA with a short sleep duration of ≤5 hours demonstrated the highest odds of chronic dizziness, showing a significantly 2.48-fold increased likelihood compared to the non-high risk for OSA with a sleep duration of 5-9 hours.

DISCUSSION

The SBQ can be beneficial when other causes do not explain chronic dizziness, helping to rule in the possibility of OSA. Educating individuals suspected of having OSA or who have been diagnosed with OSA about the importance of adequate sleep duration may help reduce the risk of chronic dizziness.

Sex and APOE genotype influence respiratory function under hypoxic and hypoxic-hypercapnic conditions

The apolipoprotein E (APOE) gene has been studied due to its influence on Alzheimer's disease (AD) development and work in an APOE mouse model recently demonstrated impaired respiratory motor plasticity following spinal cord injury (SCI). Individuals with AD often copresent with obstructive sleep apnea (OSA) characterized by cessations in breathing during sleep. Despite the prominence of APOE genotype and sex as factors in AD progression, little is known about the impact of these variables on respiratory control. Ventilation is tightly regulated across many systems, with respiratory rhythm formation occurring in the brainstem but modulated in response to chemoreception. Alterations within these modulatory systems may result in disruptions of appropriate respiratory control and ultimately, disease. Using mice expressing two different humanized APOE alleles, we characterized how sex and the presence of APOE3 or APOE4 influences ventilation during baseline breathing (normoxia) and during respiratory challenges. We show that sex and APOE genotype influence breathing during hypoxic challenge, which may have clinical implications in the context of AD and OSA. In addition, female mice, while responding robustly to hypoxia, were unable to recover to baseline respiratory levels, emphasizing sex differences in disordered breathing.NEW & NOTEWORTHY This study is the first to use whole body plethysmography (WBP) to measure the impact of APOE alleles on breathing under normoxia and during adverse respiratory challenges in a targeted replacement Alzheimer's model. Both sex and genotype were shown to affect breathing under normoxia, hypoxic challenge, and hypoxic-hypercapnic challenge. This work has important implications regarding the impact of genetics on respiratory control as well as applications pertaining to conditions of disordered breathing including sleep apnea and neurotrauma.

Could an increased risk of obstructive sleep apnoea be one of the determinants associated with disability in individuals with cardiovascular and cerebrovascular diseases?

PURPOSE

To investigate a possible association between the risk of obstructive sleep apnoea (OSA) and disability in individuals with cardiovascular or cerebrovascular diseases.

METHODS

Cross-sectional study was conducted with 373 individuals (313 with cardiovascular or cerebrovascular diseases and 60 healthy). Disability was assessed by the 12-item World Health Organization Disability Assessment Schedule (WHODAS), and the risk of OSA was assessed by STOP-BANG. Anxiety and depression symptoms, daytime sleepiness, and cognition were assessed by the Hospital Anxiety and Depression Scale (HADS), Epworth Sleepiness Scale (ESS), and Mini Mental State Examination (MMSE).

RESULTS

Greater disability was found in individuals with intermediate or high risk of OSA, considering healthy individuals (p=0.03), or individuals diagnosed with arrhythmia (p<0.01) or coronary artery disease (p=0.04). A high risk of OSA and higher WHODAS scores was significant among women as well as between OSA risk categories (p<0.01). Cognitive deficit and level of education also showed differences between OSA risk categories. Age, depression, and sleepiness were also associated with the subjects' disability (p<0.01). Gamma regression model showed higher WHODAS scores in female, in those with intermediate and high risk of OSA, and in those with depressive symptoms and cognitive deficit. Age also showed a correlation with higher WHODAS scores. The presence of all investigated cardio and cerebrovascular diseases showed an increase in the WHODAS score, implying a greater disability compared to healthy individuals.

CONCLUSION

Moderate and high risk of OSA is associated with disability, as well as gender, age, depressive symptoms, cognitive deficit, and cardiovascular diseases.

The Effects of Obstructive Sleep Apnea on the Cardiovascular System: A Comprehensive Review

Obstructive sleep apnea (OSA) is an increasingly relevant cause of cardiovascular morbidity worldwide. Although the association between OSA and the cardiovascular system is well-known, the extent of its effects is still a topic of interest, including pathophysiologic mechanisms, cardiovascular sequelae, and OSA therapies and their effects. Commonly described mechanisms of cardiovascular etiologies revolve around sympathetic activation, inflammation, and intermittent hypoxia resulting from OSA. Ultimately, these effects lead to manifestations in the cardiovascular system, such as arrhythmias, hypertension, and heart failure, among others. The resulting sequelae of OSA may also have differential effects based on gender and age; several studies suggest female gender to have more susceptibility to cardiovascular mortality, as well as an increase in age. Furthermore, several therapies for OSA, both established and emerging, show a reduction in cardiovascular morbidity and may even reduce cardiovascular burden. Namely, the establishment of CPAP has led to improvement in hypertension and cardiac function in patients with heart failure and even reduced the progression of early stages of atherosclerosis. Effective management of OSA decreases abnormal neural sympathetic activity, which results in better rhythm control and blood pressure control, both in waking and sleep cycles. With newer therapies for OSA, its effects on the cardiovascular system may be significantly reduced or even reversed after long-term management. The vast extent of OSA on the cardiovascular system, as well as current and future therapeutic strategies, will be described in detail in this review.

Reoxygenation Mitigates Intermittent Hypoxia-Induced Systemic Inflammation and Gut Microbiota Dysbiosis in High-Fat Diet-Induced Obese Rats

Background

Obstructive sleep apnea (OSA) is a prevalent sleep breathing disorder characterized by intermittent hypoxia (IH), with continuous positive airway pressure (CPAP) as its standard treatment. However, the effects of intermittent hypoxia/reoxygenation (IH/R) on weight regulation in obesity and its underlying mechanism remain unclear. Gut microbiota has gained attention for its strong association with various diseases. This study aims to explore the combined influence of IH and obesity on gut microbiota and to investigate the impact of reoxygenation on IH-induced alterations.

Methods

Diet-induced obese (DIO) rats were created by 8-week high-fat diet (HFD) feeding and randomly assigned into three groups (n=15 per group): normoxia (NM), IH (6% O2, 30 cycles/h, 8 h/day, 4 weeks), or hypoxia/reoxygenation (HR, 2-week IH followed by 2-week reoxygenation) management. After modeling and exposure, body weight and biochemical indicators were measured, and fecal samples were collected for 16S rRNA sequencing.

Results

DIO rats in the IH group showed increased weight gain (p=0.0016) and elevated systemic inflammation, including IL-6 (p=0.0070) and leptin (p=0.0004). Moreover, IH rats exhibited greater microbial diversity (p<0.0167), and significant alterations in the microbial structure (p=0.014), notably the order Clostridiales, accompanied by an upregulation of bile acid metabolism predicted pathway (p=0.0043). Reoxygenation not only improved IH-exacerbated obesity, systemic inflammation, leptin resistance, and sympathetic activation, but also showed the potential to restore IH-induced microbial alterations. Elevated leptin levels were associated with Ruminococcaceae (p=0.0008) and Clostridiales (p=0.0019), while body weight was linked to Blautia producta (p=0.0377). Additionally, the abundance of Lactobacillus was negatively correlated with leptin levels (p=0.0006) and weight (p=0.0339).

Conclusion

IH leads to gut dysbiosis and metabolic disorders, while reoxygenation therapy demonstrates a potentially protective effect by restoring gut homeostasis and mitigating inflammation. It highlights the potential benefits of CPAP in reducing metabolic risk among obese patients with OSA.

Age-Related Changes in Sleep and Its Implications for Cognitive Decline in Aging Persons With Schizophrenia: A Critical Review

BACKGROUND AND HYPOTHESIS

Cognitive impairment is a core feature of schizophrenia that worsens with aging and interferes with quality of life. Recent work identifies sleep as an actionable target to alleviate cognitive deficits. Cardinal non-rapid eye movement (NREM) sleep oscillations such as sleep spindles and slow oscillations are critical for cognition. People living with schizophrenia (PLWS) and their first-degree relatives have a specific reduction in sleep spindles and an abnormality in their temporal coordination with slow oscillations that predict impaired memory consolidation. While NREM oscillatory activity is reduced in typical aging, it is not known how further disruption in these oscillations contributes to cognitive decline in older PLWS. Another understudied risk factor for cognitive deficits among older PLWS is obstructive sleep apnea (OSA) which may contribute to cognitive decline.

STUDY DESIGN

We conducted a narrative review to examine the published literature on aging, OSA, and NREM sleep oscillations in PLWS.

STUDY RESULTS

Spindles are propagated via thalamocortical feedback loops, and this circuitry shows abnormal hyperconnectivity in schizophrenia as revealed by structural and functional MRI studies. While the risk and severity of OSA increase with age, older PLWS are particularly vulnerable to OSA-related cognitive deficits because OSA is often underdiagnosed and undertreated, and OSA adds further damage to the circuitry that generates NREM sleep oscillations.

CONCLUSIONS

We highlight the critical need to study NREM sleep in older PWLS and propose that identifying and treating OSA in older PLWS will provide an avenue to potentially mitigate and prevent cognitive decline.

Sex-dependent effects of chronic intermittent hypoxia: implication for obstructive sleep apnea

BACKGROUND

Obstructive sleep apnea (OSA) affects 10-26% of adults in the United States with known sex differences in prevalence and severity. OSA is characterized by elevated inflammation, oxidative stress (OS), and cognitive dysfunction. However, there is a paucity of data regarding the role of sex in the OSA phenotype. Prior findings suggest women exhibit different OSA phenotypes than men, which could result in under-reported OSA prevalence in women. To examine the relationship between OSA and sex, we used chronic intermittent hypoxia (CIH) to model OSA in rats. We hypothesized that CIH would produce sex-dependent phenotypes of inflammation, OS, and cognitive dysfunction, and these sex differences would be dependent on mitochondrial oxidative stress (mtOS).

METHODS

Adult male and female Sprague Dawley rats were exposed to CIH or normoxia for 14 days to examine the impact of sex on CIH-associated circulating inflammation (IL-1β, IL-6, IL-10, TNF-α), circulating steroid hormones, circulating OS, and behavior (recollective and spatial memory; gross and fine motor function; anxiety-like behaviors; and compulsive behaviors). Rats were implanted with osmotic minipumps containing either a mitochondria-targeting antioxidant (MitoTEMPOL) or saline vehicle 1 week prior to CIH initiation to examine how inhibiting mtOS would affect the CIH phenotype.

RESULTS

Sex-specific differences in CIH-induced inflammation, OS, motor function, and compulsive behavior were observed. In female rats, CIH increased inflammation (plasma IL-6 and IL-6/IL-10 ratio) and impaired fine motor function. Conversely, CIH elevated circulating OS and compulsivity in males. These sex-dependent effects of CIH were blocked by inhibiting mtOS. Interestingly, CIH impaired recollective memory in both sexes but these effects were not mediated by mtOS. No effects of CIH were observed on spatial memory, gross motor function, or anxiety-like behavior, regardless of sex.

CONCLUSIONS

Our results indicate that the impact of CIH is dependent on sex, such as an inflammatory response and OS response in females and males, respectively, that are mediated by mtOS. Interestingly, there was no effect of sex or mtOS in CIH-induced impairment of recollective memory. These results indicate that mtOS is involved in the sex differences observed in CIH, but a different mechanism underlies CIH-induced memory impairments.

Non-alcoholic fatty liver disease and sleep disorders

Studies have shown that non-alcoholic fatty liver disease (NAFLD) may be associated with sleep disorders. In order to explore the explicit relationship between the two, we systematically reviewed the effects of sleep disorders, especially obstructive sleep apnea (OSA), on the incidence of NAFLD, and analyzed the possible mechanisms after adjusting for confounding factors. NAFLD is independently associated with sleep disorders. Different sleep disorders may be the cause of the onset and aggravation of NAFLD. An excessive or insufficient sleep duration, poor sleep quality, insomnia, sleep-wake disorders, and OSA may increase the incidence of NAFLD. Despite that some research suggests a unidirectional causal link between the two, specifically, the onset of NAFLD is identified as a result of changes in sleep characteristics, and the reverse relationship does not hold true. Nevertheless, there is still a lack of specific research elucidating the reasons behind the higher risk of developing sleep disorders in individuals with NAFLD. Further research is needed to establish a clear relationship between NAFLD and sleep disorders. This will lay the groundwork for earlier identification of potential patients, which is crucial for earlier monitoring, diagnosis, effective prevention, and treatment of NAFLD.

Evaluation of risk factors for sleep-disordered breathing in dogs

BACKGROUND

Brachycephalic dogs display sleep-disordered breathing (SDB). The risk factors for SDB remain unknown.

OBJECTIVES

To identify risk factors for SDB. We hypothesized that brachycephaly, increasing severity of brachycephalic obstructive airway syndrome (BOAS), excess weight, and aging predispose to SDB.

ANIMALS

Sixty-three privately owned pet dogs were prospectively recruited: 28 brachycephalic and 35 normocephalic (mesaticephalic or dolicocephalic) dogs.

METHODS

Prospective observational cross-sectional study with convenience sampling. Recording with the neckband was done over 1 night at each dog's home. The primary outcome measure was the obstructive respiratory event index (OREI). Body condition score (BCS) was assessed, and BOAS severity was graded for brachycephalic dogs.

RESULTS

Brachycephaly was a significant risk factor for high OREI value (ratio of the geometric means 5.6, 95% confidence interval [CI] 3.2-9.9; P < .001) but aging was not (1.1, 95% CI 1.0-1.2; P = .2). Excess weight, defined as a BCS of over 5/9, (3.5, 95% CI 1.8-6.7; P < .001) was a significant risk factor. In brachycephalic dogs, BOAS-positive class (moderate or severe BOAS signs) was a significant risk factor (2.5, 95% CI 1.1-5.6; P = .03).

CONCLUSIONS AND CLINICAL IMPORTANCE

Brachycephaly decreases welfare in a multitude of ways, including disrupting sleep. Brachycephaly, increasing severity of BOAS and excess weight are risk factors for obstructive SDB.

Childhood maltreatment and sleep apnea: Findings from a cross-sectional general population study

OBJECTIVE

Cumulative evidence indicates that childhood maltreatment (CM) is associated with sleep disturbances possibly suggesting sleep apnea. However, the relation between CM and objective measures of sleep apnea as determined by polysomnography (PSG) has not yet been assessed.

METHODS

Using a cross-sectional design and based on PSG measurements from N = 962 subjects from the SHIP-Trend general population study, we used linear regression models to investigate the relationship between apnea-hypopnea (AHI) and oxygen desaturation index (ODI) and Epworth sleepiness scale (ESS) metrics and the Childhood Trauma Questionnaire (CTQ). All significant models were additionally adjusted for obesity, depression, metabolic syndrome, risky health behaviors, and socioeconomic factors.

RESULTS

While both AHI and ESS were positively associated with the CTQ sum score, ODI was not. Investigating the CTQ subscales, ESS was associated with emotional abuse and emotional neglect; AHI was associated with physical and sexual abuse as well as physical neglect. For both the sum score and the subscales of the CTQ, ESS effects were partially mediated by depressive symptoms, while AHI effects were mediated by obesity, risky health behaviors, and metabolic syndrome.

CONCLUSION

The findings of this general population study suggest an association between CM, particularly physical neglect, and objective as well as subjective indicators of sleep apnea, which were partially mediated by depressive symptoms and obesity.

Gender differences in the upper airway, craniofacial morphological and polysomnographic parameters in patients with obstructive sleep apnoea

BACKGROUND

Obstructive sleep apnoea (OSA) is a common sleep disorder characterized by repetitive episodes of upper airway collapse during sleep associated with arousals with or without oxygen desaturation.

OBJECTIVE

This study aims to assess and analyse the morphological and neurological factors associated with obstructive sleep apnoea using polysomnography study data and two-dimensional cephalometric analysis of airway and skeletal parameters and their correlation in the patients with varying severities of obstructive sleep apnoea.

METHODS

This study included 892 patients who underwent a complete work up, including a thorough history, clinical examination, standard polysomnography study and 2D cephalometric analysis to diagnose obstructive sleep apnoea. This study divided the participants into two groups based on the AHI score from the PSG study: AHI < 15 and AHI > 15 groups. The groups were further divided into male and female groups to study the prevalence of OSA. The analysis involved 13 cephalometric parameters: Seven linear and six angular measurements. The airway parameters measured in this study were minimum posterior airway space (PAS_min), hyoid bone to the mandibular plane (H_MNP) and soft palate length (SPL). All the subjects in this study underwent a standard overnight polysomnography study at the sleep centre in Samsung Medical Center.

RESULTS

A total of 892 adult participants (M: F = 727:165, mean age: 50.6 ± 13.2 years and age range: 18-85 years). AHI >15 group was significantly older with higher BMI, NC and WC compared to the AHI < 15 groups in both male and female groups. There was statistical significance observed in N1, N3, AI, ODI, lowest saturation (%) and apnoea max length between the groups (p < .001). The arousal index (AI), especially the respiratory arousal index was considerably higher in the male group. There were significantly higher values in all the PSG parameters in the male group. In the airway parameters, hyoid bone position and soft palate length showed significant differences (p < .001), whereas the PAS did not show any differences (p = .225) between the AHI <15 and AHI >15 groups. The overall skeletal cephalometric parameters showed no significant differences between the groups, whereas the gonial angle and AB to mandibular plane angle showed significant differences in the female group (p = .028, p = .041 respectively).

CONCLUSION

The partial correlation of cephalometric parameters with AHI showed a stronger correlation between the H_MNP and AHI in both men and women. The position of the hyoid bone and the soft palate length influences the progression of OSA, especially in male patients. This study found no direct association between the minimum PAS and varying severities of OSA in men and women. We speculate that more than the craniofacial morphological factors such as the sagittal and vertical position of the maxilla and the mandible, the position of the hyoid bone might be more responsible for the severity of OSA.

Prevalence of Obstructive Sleep Apnea in Head and Neck Squamous Cell Carcinoma Patients before and after Treatment

Background and Objectives: Obstructive sleep apnea (OSA) is common not only in the general population but even more so in patients with tumors of the head and neck region. Untreated, it leads to reduced quality of life, increased daytime sleepiness, and other comorbidities. The aim of this study was to determine the difference in the occurrence of OSA in the patient population with head and neck tumors compared with the general population as represented by the Trend cohort of the Study of Health in Pomerania (SHIP), and to assess the influence of tumor treatment. Materials and Methods: Between July 2018 and December 2021, preoperative polysomnography was conducted in 47 patients with histologically confirmed squamous cell carcinoma in the oropharynx, hypopharynx, or larynx. A follow-up polysomnography was performed in 23 patients 2-11 months after completing treatment. The collected data were correlated with tumor treatment and tumor size. Results: Of the included patients, 43 were male and 4 were female. Age ranged from 54 to 90 years. The pretherapeutic measurement found no significant difference in the prevalence of a pathologically elevated apnea-hypopnea index (AHI) in our patients compared with the SHIP Trend cohort. In the follow-up measurement after completion of treartment, a significant deterioration in AHI was observed. Initially, 70% of patients had an AHI > 5; after therapy, this increased to 87% (p = 0.008). The effect was particularly pronounced in the group of patients with advanced tumor stages who had received primary chemoradiation. Conclusions: OSA is a relevant condition in patients with head and neck cancer. Tumor treatment can lead to an increased occurrence of sleep-related breathing disorders, especially in patients with advanced tumor stages undergoing primary chemoradiation. Additional studies are necessary to better understand the exact mechanism involved.

Guideline for the Management of Diabetes Mellitus in the Elderly in China (2024 Edition)

With the deepening of aging in China, the prevalence of diabetes in older people has increased noticeably, and standardized diabetes management is critical for improving clinical outcomes of diabetes in older people. In 2021, the National Center of Gerontology, Chinese Society of Geriatrics, and Diabetes Professional Committee of Chinese Aging Well Association organized experts to write the first guideline for diabetes diagnosis and treatment in older people in China, the Guideline for the Management of Diabetes Mellitus in the Elderly in China (2021 Edition). The guideline emphasizes that older patients with diabetes are a highly heterogeneous group requiring comprehensive assessment and stratified and individualized management strategies. The guideline proposes simple treatments and de-intensified treatment strategies for older patients with diabetes. This edition of the guideline provides clinicians with practical and operable clinical guidance, thus greatly contributing to the comprehensive and full-cycle standardized management of older patients with diabetes in China and promoting the extensive development of clinical and basic research on diabetes in older people and related fields. In the past 3 years, evidence-based medicine for older patients with diabetes and related fields has further advanced, and new treatment concepts, drugs, and technologies have been developed. The guideline editorial committee promptly updated the first edition of the guideline and compiled the Guideline for the Management of Diabetes Mellitus in the Elderly in China (2024 Edition). More precise management paths for older patients with diabetes are proposed, for achieving continued standardization of the management of older Chinese patients with diabetes and improving their clinical outcomes.

Prevalence of headaches and their relationship with obstructive sleep apnea (OSA) - Systematic review and meta-analysis

Obstructive sleep apnea (OSA) is one of the most common sleep disorders; however, there are inconsistent results about the connection and occurrence of primary and secondary headaches in OSA. Therefore, the primary objectives were to estimate the prevalence and potential relationship between all types of headaches and OSA. A systematic review was conducted according to PRISMA 2020 guidelines. Studies were searched in PubMed, Embase, and Web of science up to July 2023. The Joanna Briggs Institute tool assessed the risk of bias. 1845 articles were identified, and 23 studies describing 15,402 patients were included. Pooled prevalence of all headaches in OSA was 33% (95% CI: 0.25-0.41), 33% for morning headaches (95% CI: 0.24-0.45), 25% for sleep apnea headaches (95% CI: 0.18-0.34), 19% for tension-type headache (95% CI: 0.15-0.23), and 16% for migraine (95% CI: 0.09-0.26). Relative risk for the occurrence of headache in OSA patients compared to the non-OSA people was 1.43 (95% CI: 0.92-2.25). OSA females and males had morning headaches with similar frequency. The prevalence of headaches in OSA was moderate. OSA did not increase the risk of headache. There is a need to conduct further studies focused on bidirectional connections between sleep disorders and headaches.

Sex-dependent effects of chronic intermittent hypoxia: Implication for obstructive sleep apnea

Background Obstructive sleep apnea (OSA) affects 10-26% of adults in the United States with known sex differences in prevalence and severity. OSA is characterized by elevated inflammation, oxidative stress (OS), and cognitive dysfunction. However, there is a paucity of data regarding the role of sex in the OSA phenotype. Prior findings suggest women exhibit different OSA phenotypes than men, which could result in under-reported OSA prevalence in women. To examine the relationship between OSA and sex, we used chronic intermittent hypoxia (CIH) to model OSA in rats. We hypothesized that CIH would produce sex-dependent phenotypes of inflammation, OS, and cognitive dysfunction, and these sex differences would be dependent on mitochondrial oxidative stress (mtOS). Methods Adult male and female Sprague Dawley rats were exposed to CIH or normoxia for 14 days to examine the impact of sex on CIH-associated circulating inflammation (IL-1β, IL-4, IL-6, IL-10, TNF-α), circulating OS, and behavior (recollective and spatial memory; gross and fine motor function; anxiety-like behaviors; and compulsive behaviors). A subset of rats was implanted with osmotic minipumps containing either a mitochondria-targeting antioxidant (MitoTEMPOL) or saline vehicle 1 week prior to CIH initiation to examine how inhibiting mtOS would affect the CIH phenotype. Results Sex-specific differences in CIH-induced inflammation, OS, motor function, and compulsive behavior were observed. In female rats, CIH increased inflammation (plasma IL-6 and IL-6/IL-10 ratio) and impaired fine motor function. Conversely, CIH elevated circulating OS and compulsivity in males. These sex-dependent effects of CIH were blocked by inhibiting mtOS. Interestingly, CIH impaired recollective memory in both sexes but these effects were not mediated by mtOS. No effects of CIH were observed on spatial memory, gross motor function, or anxiety-like behavior, regardless of sex. Conclusions Our results indicate that the impact of CIH is dependent on sex, such as an inflammatory response and OS response in females and males, respectively, that are mediated by mtOS. Interestingly, there was no effect of sex or mtOS in CIH-induced impairment of recollective memory. These results indicate that mtOS is involved in the sex differences observed in CIH, but a different mechanism underlies CIH-induced memory impairments.

Fractional exhaled nitric oxide-a possible biomarker for risk of obstructive sleep apnea in snorers

STUDY OBJECTIVES

Airway inflammation in patients with obstructive sleep apnea (OSA) has been described and can be assessed by measuring the biomarker fractional exhaled nitric oxide (FeNO). In this pilot study, we investigated FeNO measurements in identification of OSA among persons with snoring.

METHODS

In this study we aimed to investigate (1) if FeNO could be used in screening for OSA, (2) if daytime sleepiness correlated to FeNO levels, and (3) whether asthma affected FeNO levels. Persons with snoring were prospectively included in three primary care ear, nose, and throat clinics. Patients underwent spirometry, FeNO tests, and partial polygraphy. They filled out questionnaires on sinonasal and asthma symptoms, daytime sleepiness, and quality of life. Current smokers, patients with upper airway inflammatory conditions, and patients treated with steroids were excluded.

RESULTS

Forty-nine individuals were included. Median apnea-hypopnea index was 11.4, mean age was 50.9 years, and 29% were females. OSA was diagnosed in 73% of the patients of whom 53% had moderate-severe disease. Patients with moderate-severe OSA had significantly higher FeNO counts than patients with no or mild OSA (P = .024). Patients younger than 50 years with a FeNO below 15 had the lowest prevalence of moderate-severe OSA. No correlation was found between FeNO measurements and daytime sleepiness, and asthma did not affect FeNO levels.

CONCLUSIONS

We found a low prevalence of moderate-severe OSA in persons with snoring when FeNO and age were low. This might be considered in a future screening model, though further studies testing the FeNO cutoff level and the diagnostic accuracy are warranted.

CLINICAL TRIAL REGISTRATION

Registry: ClinicalTrials.gov; Name: NO Measurements in Screening for Asthma and OSA, in Patients With Severe Snoring; URL: https://clinicaltrials.gov/study/NCT03964324; Identifier: NCT03964324.

CITATION

Kiaer E, Ravn A, Jennum P, et al. Fractional exhaled nitric oxide-a possible biomarker for risk of obstructive sleep apnea in snorers. J Clin Sleep Med. 2024;20(1):85-92.

Obstructive Sleep Apnea Among Patients with Mild Cognitive Impairment

Background

Obstructive sleep apnea (OSA) is associated with cognitive disorders, but little is known about prevalence of co-occurring OSA and mild cognitive impairment (MCI) as well as about co-occurring OSA and Alzheimer's disease (AD). Pathophysiological models integrating OSA, cognitive deficits and neurodegeneration remain speculative. Findings in this area could contribute to the knowledge about pathophysiological processes in cognitive disorders and neurodegenerative processes, be helpful for the diagnosis of cognitive disorders and provide approaches for the treatment of cognitive disorders.

Objective

Examining the prevalence of OSA and patterns of cognitive deficits as well as AD biomarker profiles associated with OSA in a cohort of 104 MCI patients.

Methods

Assessments used include: respiratory polygraphy, The Consortium to Establish a Registry for Alzheimer's Disease Neuropsychological Battery (CERAD NB), Tau, phosphoTau181, amyloid-β-1-42/1-40, 18F-fluorodeoxyglucose positron emission tomography (F18-FDG-PET).

Results

Prevalence of OSA of any severity: 58,7% (Apnea Hypopnea Index (AHI)≥5/h), OSA in a moderate-to-severe extent (AHI≥15/h): 25%. Only 13.1% of MCI patients with OSA reported daytime sleepiness. MCI-OSA patients showed no specific neuropsychological pattern. Presence of OSA was not associated with specific AD biomarker profiles in the whole study group besides a positive association between AD positivity in an AD biomarker sub cohort.

Conclusions

OSA is highly prevalent in patients with MCI. It might often remain undiagnosed as only a small number of MCI-OSA patients report daytime sleepiness. OSA could contribute to MCI symptoms and even to AD pathology. Further research is needed to validate these findings and to investigate possible pathophysiological relationships between OSA and MCI as well as between OSA and AD.

Obstructive sleep apnea increases the risk of herpes zoster and postherpetic neuralgia

OBJECTIVE

Diseases associated with chronic pain are typically a major source of stress for patients; and have been linked to herpes zoster (HZ) development. Here, we investigated whether obstructive sleep apnea (OSA) is a potential stressor that increases the risk of HZ and postherpetic neuralgia (PHN) in affected individuals.

METHODS

The data used in this study were obtained from the National Health Insurance Research Database. The study cohort included patients aged between 20 and 100 years who had OSA during the period from 2000 to 2017 (with tracking completed until 2018). The case group and the control group were matched at a 1:1 ratio on the basis of age, sex, comorbidities, and index year, with patients who had outcomes before the index date being excluded. The outcomes considered in this study were HZ and PHN. The risk of HZ and PHN with and without OSA was calculated, and age, sex, comorbidities, and index year were adjusted for.

RESULTS

There were 25,211 patients in each group. Patients with OSA had a significantly higher risk of HZ (adjusted hazard ratio [aHR] = 1.22) than those without did. The patients with OSA had also a significantly higher risk of PHN (aHR = 1.36) than those without did. In term of comorbidities, the patients with OSA without (aHR = 1.28) and with (aHR = 1.17) comorbidities had a significantly higher risk of HZ compared with those without OSA. In addition, the patients with OSA but no other comorbidities (aHR = 1.68) had a significantly higher risk of PHN than those without did.

CONCLUSION

OSA increases the risk of not only HZ but also PHN. Therefore, patients with OSA should be aware of the potential effect of the disease on their stress levels, as well as the increased risk of developing HZ and PHN.

Characterization of risk factors for obstructive sleep apnea and its association with absenteeism among nurses

PURPOSE

To characterize risk factors associated with obstructive sleep apnea (OSA) and its relationship with nurses' absenteeism.

METHODS

A cross-sectional study was conducted from 2018 to 2020 at a 1,000-bed academic hospital complex and biomedical research facility in Tehran, Iran. Participants were selected through consecutive sampling after obtaining ethical approval and informed consent. Data on demographics, medical conditions, occupational characteristics, and absenteeism were collected through face-to-face interviews. The STOP-Bang questionnaire was utilized to assess the probability of OSA. Statistical tests included the Mann-Whitney U, t-test, Chi-square, and multivariable regression.

RESULTS

In this study involving 304 nurses, the majority were female (81.3%), with an average age of 35. About 27 participants (8.9%) had a high probability of OSA, with male sex, older age, higher body mass index, neck circumference, and diastolic BP identified as the main determinants of OSA. Additionally, shift work and night shifts were associated with increased absenteeism, while sex showed no significant association with absenteeism rates among nurses.

CONCLUSION

Male sex, neck circumference (obesity), night shifts, and diastolic BP can predict OSA risk. However, unauthorized absence from work is not associated with a high risk for OSA (STOP-BANG ≥3) or the individual risk factors of OSA.

Obstructive sleep apnoea-hypopnoea syndrome

Obstructive sleep apnoea-hypopnoea syndrome (OSAHS) is a common disorder characterised by repetitive episodes of the complete or partial collapse of the pharyngeal airway during sleep. This results in cessation (apnoea) or reduction (hypopnoea) of airflow, leading to oxygen desaturation and sleep fragmentation. An individual's disposition to develop OSAHS depends on the collapsibility of a segment of the upper airway. The degree of collapsibility can be quantified by the balance between occluding or extraluminal pressures of the surrounding tissues. Patients can experience snoring, unrefreshing sleep, witnessed apnoeas, waking with a choking sensation and excessive daytime sleepiness. OSAHS has a broad range of consequences, including cardiovascular, metabolic, and neurocognitive sequelae. Treatment options include lifestyle measures, in particular weight loss, and strategies to maintain upper airway patency overnight, including continuous positive airway pressure, mandibular advancement devices and positional modifiers.

Inflammatory burden, lifestyle and atherosclerotic cardiovascular disease: insights from a population based cohort study

The inflammatory burden as measured by high-sensitivity C-reactive Protein (hsCRP) is recognized as a cardiovascular risk factor, which can however be affected by lifestyle-related risk factors (LRF). Up-to-date the interplay between hsCRP, LRF and presence and extent of atherosclerotic disease is still largely unknown, which we therefore sought to investigate in a contemporary population-based cohort. We included participants from the cross-sectional population-based Hamburg City Health Study. Affected vascular beds were defined as coronary, peripheral, and cerebrovascular arteries. LRF considered were lack of physical activity, overweight, active smoking and poor adherence to a Mediterranean diet. We computed multivariable analyses with hsCRP as the dependent variable and LRF as covariates according to the number of vascular beds affected. In the 6765 individuals available for analysis, we found a stepwise increase of hsCRP concentration both according to the number of LRF present as well as the number of vascular beds affected. Adjusted regression analyses showed an independent association between increasing numbers of LRF with hsCRP levels across the extent of atherosclerosis. We demonstrate increasing hsCRP concentrations according to both the number of LRF as well as the extent of atherosclerosis, emphasizing the necessity of lifestyle-related risk factor optimization.

Worldwide prevalence and associated risk factors of obstructive sleep apnea: a meta-analysis and meta-regression

PURPOSE

This study aimed to identify the prevalence of obstructive sleep apnea (OSA) and associated risk factors globally.

METHODS

Six databases and registrations and three grey databases were explored for observational field research. Independently and impartially paired reviewers selected research, gathered data, and evaluated the methodological quality. Heterogeneity was investigated using subgroup analysis and meta-regression following the moderating variable in a meta-analysis of proportions with a random-effects model. The critical appraisal instrument developed by the Joanna Briggs Institute was used to evaluate the listed studies' methodology. The certainty of the evidence was evaluated using the GRADE tool.

RESULTS

A total of 8236 articles were collected during the database search, resulting in 99 articles included for qualitative synthesis, and 98 articles were included for the meta-analysis. The estimated combined prevalence of OSA was 54% [CI 95% = 46-62%; I2 = 100%]. Mean age, percentage of moderate-severe cases, and the sample's body mass index (BMI) did not affect the heterogeneity that was already present when meta-regressed (p > 0.05). Ninety-one studies were deemed to have a low risk of bias, while eight were deemed to have a moderate risk. For OSA prevalence outcomes, the GRADE criteria were considered very low.

CONCLUSION

Approximately half of the people worldwide have OSA. High BMI, increasing age, and male gender are described as risk factors in the literature, but these covariates do not affect pre-existing heterogeneity.

CPAP adherence after ambulatory and in-hospital management in patients aged 65 years and older

OBJECTIVES

The aims of this study are to evaluate the early adherence to CPAP treatment in patients aged 65 years and older and to compare ambulatory (ACPAP) and in-hospital (HCPAP) management in starting CPAP treatment.

METHODS

Adherence to CPAP therapy at 3 months was retrospectively studied in patients on whom CPAP therapy was initiated between 1 January 2020 and 31 December 2021. Patients in the ACPAP group were selected based on the current Belgian reimbursement criteria (OAHI ≥30/h and few comorbidities).

RESULTS

146 patients were studied (median OAHI 43.35/h [32.02; 57.40]; median age 69 [67.0; 73.0]): 116 (79.5%) patients in the HCPAP and 30 (20.5%) in the ACPAP group. Based on an adherence threshold of average CPAP use of ≥ 4 hours per day, 120 (82%) patients were adherent to the treatment; 94 (81%) patients in the HCPAP and 26 (86.7%) in the ACPAP group. The median CPAP use for the total population was 6.4 h/day [4.89; 7.34], reaching 6.3 h/d [4.79; 7.15] for the HCPAP group and 6.8 h/d [6.21; 8.06] for the ACPAP group (p = 0.019). Insomnia was a significant risk factor for non-adherence (OR 5.16 [1.64; 16.08], p = 0.0043) but the ACPAP method was not (OR 0.66 [0.18; 1.91], p = 0.4748).

CONCLUSION

Early CPAP adherence in patients ≥ 65 years old was good in terms of average use per day and proportion of adherent patients. ACPAP method was not a risk factor for lower CPAP adherence in patients presenting severe OSAS (OAHI ≥30/h) and few comorbidities.

Complications and predictors associated with moderate to severe obstructive sleep apnoea in bariatric surgery: Evaluation of routine obstructive sleep apnoea screening

PURPOSE

Obstructive sleep apnoea (OSA) is a breathing disorder resulting in blockage of airflow and hypo-oxygenation. The incidence of OSA in patients with class 2 or 3 obesity (Body Mass index, BMI >35) is 60-70%. Unfortunately, most bariatric patients are unaware they suffer from OSA. Untreated OSA can lead to perioperative cardiopulmonary complications. The aim of this study was to identify predictors associated with moderate to severe OSA and asses the incidence of OSA-related complications in a large cohort of patients who underwent OSA-screening and treatment if indicated before bariatric surgery.

METHODS

All consecutive patients who underwent primary bariatric surgery between September 2013 and September 2019 were included. Univariable and multivariable logistic regression analysis was performed to identify potential predictors for moderate to severe OSA using sleep studies.

RESULTS

A total of 2872 patients who underwent bariatric surgery were included for analysis. Overall, OSA was identified in 62.5% of all patients and moderate to severe OSA (AHI ≥15) in 28.6%. Independent predictors for moderate to severe OSA were male gender (p < 0.001), age (p < 0.001), preoperative BMI (p < 0.001), preoperative waist circumference (p < 0.001), hypertension (p < 0.001), and dyslipidaemia (p = 0.046). The incidence of OSA-related complications was low (0.8%) and not significantly different among the different OSA severity classes.

CONCLUSION

This is the largest study to assess OSA presence and OSA-related complications in patients undergoing bariatric surgery. The incidence of potential OSA-related complications was low (0.8%). We believe focus could be shifted towards more cost-efficient strategies where OSA screening is omitted such as perioperative continuous monitoring.

Anesthesia for Morbidly Obese Patients

BACKGROUND

The prevalence of morbid obesity (BMI >35 kg/m2) has risen steadily in recent decades. With the corresponding rise in the number of bariatric operations, anesthesiologists deal with this patient group more commonly than before, particularly in specialized centers.

METHODS

This review is based on publications retrieved by a selective search in PubMed, including current guidelines and recommendations issued by specialist societies, as well as expert opinion.

RESULTS

In the anesthesiological care of morbidly obese patients, a preoperative assessment and risk stratification are just as important as the thoughtful selection of the anesthesia technique, the drugs used and their dosage, and perioperative management. A thorough understanding of the pathophysiological changes and comorbidities of morbid obesity and the associated risks is essential. The risk of pulmonary complications such as respiratory failure, hypoxia, and apnea is markedly higher in morbidly obese patients, especially those with obstructive sleep apnea. Short-acting, less lipophilic anesthetic drugs are particularly useful, as is multimodal pain therapy for the avoidance of high opiate doses. The indication for intensified postoperative monitoring depends on the patient's preexisting illnesses, the type of anesthesia, and the type of surgical procedure. Regional anesthetic techniques should be used if possible.

CONCLUSION

The perioperative care of morbidly obese patients presents special challenges. The anesthesiologist must be aware of potential comorbidities, specific risks, and pathophysiological changes in order to provide adequate care to this patient group.

Understanding, diagnosing, and treating Myalgic encephalomyelitis/chronic fatigue syndrome - State of the art: Report of the 2nd international meeting at the Charité Fatigue Center

Myalgic Encephalomyelitis/Chronic Fatigue Syndrome (ME/CFS) is a devastating disease affecting millions of people worldwide. Due to the 2019 pandemic of coronavirus disease (COVID-19), we are facing a significant increase of ME/CFS prevalence. On May 11th to 12th, 2023, the second international ME/CFS conference of the Charité Fatigue Center was held in Berlin, Germany, focusing on pathomechanisms, diagnosis, and treatment. During the two-day conference, more than 100 researchers from various research fields met on-site and over 700 attendees participated online to discuss the state of the art and novel findings in this field. Key topics from the conference included: the role of the immune system, dysfunction of endothelial and autonomic nervous system, and viral reactivation. Furthermore, there were presentations on innovative diagnostic measures and assessments for this complex disease, cutting-edge treatment approaches, and clinical studies. Despite the increased public attention due to the COVID-19 pandemic, the subsequent rise of Long COVID-19 cases, and the rise of funding opportunities to unravel the pathomechanisms underlying ME/CFS, this severe disease remains highly underresearched. Future adequately funded research efforts are needed to further explore the disease etiology and to identify diagnostic markers and targeted therapies.

Sleep disorders and risk of infertility: A meta-analysis of observational studies

OBJECTIVE

The purpose of this study was to determine the relationship between sleep disorders and risk of infertility.

METHOD

Three databases (PubMed, Embase, and Cochrane Library) were searched form their inception to April 30, 2023. Information of study design, control group and experimental group, number of participants, and study outcomes was extracted. The quality of the studies was evaluated using the Newcastle-Ottawa Scale (NOS scale) and the Agency for Healthcare Research and Quality (AHRQ scale). Narrative synthesis and meta-analysis were used to analyze these studies.

RESULT

Eight cohort, cross-sectional, and case-control studies were considered. The reviewed studies were high-quality. Pooled analysis showed that the risk of infertility was 1.43-fold higher in patients with sleep disturbance (HR = 1.43, 95% CI, 0.97-2.11, z = 1.79), but this was not statistically different; the risk was 1.58-fold higher in patients with OSA compared to those without OSA (HR = 1.58, 95%, CI, 0.99-2.52, z = 1.91), but this was not statistically significant. Wake-up time is also associated with infertility (OR = 1.14; 95%CI = 1.01-1.28; P = 0.037). For every hour they stay awake beyond 8:00 AM, participants had a 41% higher risk of infertility (P = 0.004). The early-to-bed/late-to-rise (EL), LE, and LL groups had a higher risk of infertility than the EE group.

CONCLUSION

The present study did not find an association between sleep disorders and the risk of infertility. Therefore, more observational studies are warranted to explore the association between sleep disorders and the risk of infertility.

Major Adverse Cardiac and Cerebrovascular Events in Geriatric Patients with Obstructive Sleep Apnea: An Inpatient Sample Analysis

BACKGROUND

Obstructive sleep apnea (OSA) is associated with an increased risk of major cardiac and cerebrovascular events (MACCE). However, data on the burden and predictors of MACCE in geriatric patients with OSA (G-OSA) remain limited.

METHODS

Using the National Inpatient Sample from 2018, we identified G-OSA admissions (age ≥ 65 years) and divided them into non-MACCE vs. MACCE (all-cause mortality, stroke, acute myocardial infarction, and cardiac arrest). We compared the demographics and comorbidities in both cohorts and extracted the odds ratio (multivariate analysis) of MACCE and associated in-hospital mortality.

RESULTS

Out of 1,141,120 geriatric obstructive sleep apnea G-OSA admissions, 9.9% (113,295) had MACCE. Males, Asians, or the Pacific Islander/Native American race, and patients from the lowest income quartile revealed a higher MACCE rate. Significant clinical predictors of MACCE in elderly OSA patients on multivariable regression analysis in decreasing odds were pulmonary circulation disease (OR 1.47, 95% CI 1.31-1.66), coagulopathy (OR 1.43, 95% CI 1.35-1.50), peripheral vascular disease (OR 1.34, 95% CI 1.28-1.40), prior sudden cardiac arrest (OR 1.34, 95% CI 1.11-1.62), prior myocardial infarction (OR 1.27, 95% CI 1.22-1.33), fluid and electrolyte imbalances (OR 1.25, 95% CI 1.20-1.29), male sex (OR 1.22, 95% CI-1.18-1.26), hyperlipidemia (OR 1.20, 95% CI 1.16-1.24), low household income (OR 1.19, CI 1.13-1.26), renal failure (OR 1.15, 95% CI 1.12-1.19), diabetes (OR 1.14, 95% CI 1.10-1.17), metastatic cancer (OR 1.14, 95% CI 1.03-1.25), and prior stroke or TIA (OR 1.12, 95% CI 1.07-1.17) (All p value < 0.05).

CONCLUSIONS

This study emphasizes the significant association between obstructive sleep apnea (OSA) and major cardiac and cerebrovascular events (MACCE) in the geriatric population. Among the elderly OSA patients, a substantial 9.9% were found to have MACCE, with specific demographics like males, Asian or Pacific Islander/Native American individuals, and those from the lowest income quartile being particularly vulnerable. The study sheds light on several significant clinical predictors, with pulmonary circulation disease, coagulopathy, and peripheral vascular disease topping the list. The highlighted predictors provide valuable insights for clinicians, allowing for better risk stratification and targeted interventions in this vulnerable patient cohort. Further research is essential to validate these findings and inform how tailored therapeutic approaches for geriatric OSA patients can mitigate MACCE risk.

CLINICAL IMPLICATIONS

Elderly individuals with a high risk for MACCE should undergo routine OSA screening using tools like the sensitive STOP-BANG Questionnaire. Implementing CPAP treatment can enhance cardiovascular outcomes in these patients.

Association between the Obstructive Sleep Apnea and Cephalometric Parameters in Teenagers

BACKGROUND

OSA is a common problem in children and adolescents. Angle class II malocclusion, a tendency toward the vertical type of growth, causes a decrease in the volume of the oral air space, increasing the risk of OSAS. The aim of this study was to evaluate the relationship between cephalometric and OSA parameters, to develop collaborative approaches between orthodontists and somnologists in the treatment of adolescents with OSA.

METHODS

We analyzed data from 41 adolescents with OSA. Their mean age was 15.8 ± 1.08 years. Orthodontic and polysomnographic examinations of patients were conducted. Statistical analysis was performed in SPSS 19.0.0.

RESULTS

Most often in patients with distal occlusion, a violation of the harmony in the development of the dental system was observed. The sagittal incisive fissure, characteristic of a distal occlusion, was absent due to the palatal inclination of the upper incisors in 25 (60.98%) patients. The SNB was 79.4 ± 3.1°, indicating a distal position of the mandible relative to the anterior cranial base. The SNA exceeded the normal value, which is one of the prerequisites for mandibular retrognathia. The ANB angle was 4.3 ± 1.9°. Tonsillar hypertrophy affected 6 patients, 21 had adenoid hypertrophy, and 3 had both of them. Movements of the masticatory muscles during sleep were recorded in 22.0% of patients.

CONCLUSION

To improve the quality of diagnosis and treatment of OSA, a multidisciplinary approach is needed that will correct the processes of child growth and development.

The Sleepiness-Depression Link in Obstructive Sleep Apnea: Preliminary Results on the Mediation of Impulsivity

BACKGROUND

Emotional impulsivity has been found to be relevant in explaining the association between sleep problems and depressive symptoms, suggesting the potential role of impulsivity as a key underlying mechanism of this link. The objective of this study was to take a preliminary step in understanding the mediating role of impulsivity in the relation between excessive daytime sleepiness (EDS) and depression in patients with obstructive sleep apnea syndrome (OSAS) and to compare psychological and demographic characteristics between different levels of daytime sleepiness.

METHODS

A total of 138 patients with OSAS underwent polygraphic cardiorespiratory monitoring and completed a series of questionnaires investigating perceived sleepiness, depression, impulsivity, and other psychological characteristics. A mediational model was tested in order to assess whether impulsivity mediated the relation between sleepiness and depressive symptoms while controlling for the effects of age, sex, BMI, and oxygen saturation parameters.

RESULTS

the mediation model showed that there was a significant indirect effect of impulsivity in the sleepiness-depression link (αβ = 0.084 [0.0243-0.1617]).

CONCLUSIONS

The here-presented results showed that the sleepiness-depression link is not direct as previous studies asserted, but instead it may be better explained by impulsivity. Research and practical implications are discussed.

The effects of intermittent hypoxia on hepatic expression of fatty acid translocase CD36 in lean and diet-induced obese mice

BACKGROUND

Both obstructive sleep apnea (OSA) and non-alcoholic fatty liver disease (NAFLD) are prevalent within obese individuals. We aimed to investigate the effects of intermittent hypoxia (IH), a clinical feature of OSA, on hepatic expression of fatty acid translocase (CD36) in relation to liver injury in lean and diet-induced obese mice.

METHODS

Four-week-old male C57BL/6J mice were randomized to standard diet (SD) or high fat (HF) diet groups. At 13-week-old, all mice were exposed to either air or IH (IH30; thirty hypoxic episodes per hour) for four weeks. We assessed liver injury through lipid profile, oxidative and inflammatory stress, histological scoring and hepatic CD36 expression.

RESULTS

In lean mice, IH elevated serum and hepatic triglyceride and free fatty acid (FFA) levels, in line with upregulation of hepatic CD36 expression and myeloperoxidase (MPO)-positive cells in support of inflammatory infiltrates along with increase in serum malondialdehyde (MDA), C-X-C motif chemokine ligand 1(CXCL-1) and monocyte chemoattractant protein-1 (MCP-1). In diet-induced obese mice, an increase in hepatic alanine transaminase (ALT) activity, serum and hepatic levels of lipid parameters and inflammatory markers, serum MDA level, hepatic expressions of CD36 and α-smooth muscle actin (α-SMA), and MPO-positive cells was observed. IH potentiated hepatic ALT activity, serum CXCL-1 and hepatic interleukin-6 (IL-6), in line with inflammatory infiltrates, but paradoxically, reduced hepatic FFA level and hepatic CD36 expression, compared to obese mice without IH exposure. However, IH further augmented diet-induced liver steatosis and fibrosis as shown by histological scores.

CONCLUSION

This study contributes to support that IH featuring OSA may lead to liver injury via differential regulation of hepatic CD36 expression in lean and diet-induced obese mice.

Systematic review and meta-analysis of the prevalence of obstructive sleep apnea in Indian adults

Obstructive sleep apnea (OSA) is a common sleep disorder associated with considerable morbidity. However, there is an underrepresentation of data from India and other developing countries in global reviews of OSA prevalence. This systematic review and meta-analysis examined the prevalence of OSA in India. The MEDLINE, Embase, and Scopus databases were searched for articles that reported the prevalence of OSA in the general Indian adult population using sleep studies. Eight studies were included comprising 11,009 subjects with mean age ranging from 35.5 to 47.8 years. On the Joanna Briggs Institute (JBI) checklist for prevalence studies, the study quality ranged from 3/9 to 9/9. Meta-analysis was performed using the random-effects model. The pooled prevalence of OSA (AHI ≥5 events/hour) was 11% overall (95% CI: 7%-15%; I2 = 98.0%, p<0.001), 13% in males (95% CI: 7%-18%; I2 = 96.0%, p<0.001), and 5% in females (95% CI: 3%-7%; I2 = 73.3%, p = 0.01). The pooled prevalence of moderate-to-severe OSA (AHI ≥15 events/hour) was 5% (95% CI: 2%-8%, I2 = 95.3%; p = 0.01). Based on these findings, approximately 104 million Indians of working age suffer from OSA, of whom 47 million have moderate-to-severe OSA. This represents a major public health problem in India with important implications for the global burden of the disease.

Patient-reported outcomes with hypoglossal nerve stimulation for treatment of obstructive sleep apnea: a systematic review and meta-analysis

INTRODUCTION

Hypoglossal nerve stimulation (HNS) has recently been introduced as an alternative treatment for patients with OSA. A large number of studies have demonstrated substantial changes in OSA with this therapy by reducing respiratory events and improving symptoms such as daytime sleepiness and quality of life. The objective of this review was to conduct a systematic review and meta-analysis to evaluate patient-reported outcomes and experience with HNS therapy.

METHODS

A systematic literature search of MEDLINE, Cochrane, and Web of Science was performed to identify randomized controlled and observational studies reporting subjective outcomes with different HNS systems in patients with OSA. Abstracts of 406 articles were screened and a subset of 55 articles were reviewed for eligibility. Risk of bias was assessed using the ROBINS-I tool. Meta-analysis using RevMan was performed when > 2 studies were identified that reported data on a specific outcome.

RESULTS

Thirty-four publications reporting data on 3785 patients with a mean follow-up of 11.8 ± 12.2 months were identified and included in the meta-analysis. The analysis revealed a pooled effect of 4.59 points improvement in daytime sleepiness as measured by the ESS questionnaire (Z = 42.82, p < .001), 2.84 points improvement in daytime functioning as measured by the FOSQ score (Z = 28.38, p < .001), and 1.77 points improvement in sleep quality as measured by the PSQI questionnaire (Z = 2.53, p = .010). Patient-reported experience was consistently positive and revealed additional relevant aspects from this perspective.

CONCLUSION

HNS therapy significantly improves quality of life in patients with OSA and reliably produces clinically meaningful effects on daytime sleepiness, daytime functioning, and sleep quality. Treatment regularly meets or exceeds the minimum clinically important differences defined for the respective instruments. Additional research is needed to further investigate effects on quality of life beyond improvements in daytime sleepiness and daytime functioning.