[Cardiovascular risk and obstructive sleep apnea]

Impact of Nasal Pathology on Efficacy of Hypoglossal Nerve Stimulation for Obstructive Sleep Apnea

OBJECTIVES

Hypoglossal nerve stimulation (HNS) has emerged as a treatment for obstructive sleep apnea (OSA). While current literature suggests comorbid nasal pathology can decrease quality of life (QoL) in OSA populations, its impact on HNS efficacy has been less explored. This study assesses whether the presence of nasal pathology changes HNS efficacy in improving sleep outcomes in OSA patients.

METHODS

A retrospective analysis evaluated 90 patients who underwent HNS implantation. Treatment efficacy and QoL were assessed preoperatively and postoperatively with apnea-hypopnea index (AHI), Epworth sleepiness scale (ESS), and functional outcomes of sleep questionnaire (FOSQ-10). Nasal exam and nasopharyngoscopy findings derived four groups: normal nasal findings (n = 44), positive anterior rhinoscopy findings (n = 32), positive nasopharyngoscopy findings (n = 36), and any positive nasal finding (n = 46). Septal deviation, septal perforation, polyps, masses, vestibular stenosis, and turbinate hypertrophy were considered positive findings. Outcomes within and across groups were analyzed using t-tests, Mann-Whitney U-tests, and Wilcoxon signed-rank tests.

RESULTS

Both AHI and ESS scores significantly improved across all groups (p < 0.05) following HNS. FOSQ-10 in patients with positive anterior rhinoscopy findings did not significantly improve. Average FOSQ-10 improvement was significantly greater in the control group compared to the positive anterior rhinoscopy findings (p < 0.05). All groups met Sher15 and Sher20 criteria at similar rates.

CONCLUSIONS

Comorbid nasal pathology does not diminish the effectiveness of HNS in treating OSA, with all groups showing significant improvement in AHI and ESS scores. However, impacts on broader QoL, measured by FOSQ-10, warrant further investigation.

LEVEL OF EVIDENCE: 3

A comprehensive analysis of microRNA alteration in an ApoE(-/-) mice model of white adipose tissue injury induced by chronic intermittent hypoxia

Background

MicroRNAs (miRNAs) represent a class of noncoding small RNAs and are implicated in many diseases. However, the role of miRNA in obstructive sleep apnea (OSA)-induced white adipose tissue (WAT) dysfunction remains to be fully elucidated. Using miRNA sequencing (miRNA-seq), we uncovered the miRNA expression profiles in chronic intermittent hypoxia (CIH)-induced WAT dysfunction mice.

Methods

We established an apolipoprotein-deficient (ApoE-/-) CIH mouse model and identified differentially expressed miRNAs (DEmiRs) using miRNA-seq technology. With the help of Gene Ontology (GO) functional enrichment and the Kyoto Encyclopedia of Genes and Genomes (KEGG) pathway analyses, we determined the biological functions of these DEmiRs. In addition, RT-qPCR was performed for further evaluation of the sequencing data. Finally, we constructed a conserved negative correlation (CNC) network to expound the relationship between miRNA and target genes.

Results

Overall, 13 miRNAs were found to be upregulated and 18 miRNAs downregulated in the CIH-induced mouse model of WAT dysfunction. KEGG pathway analysis results indicated that the lysosome pathway participated in CIH-induced WAT dysfunction. Then, eight miRNAs were shortlisted for RT-qPCR validation. Based on the data, we chose these DEmiRs to construct a miRNA-mRNA regulatory network.

Conclusion

Overall, we identified 31 DEmiRs in the ApoE-/- CIH mouse model. Our findings may play a major role in explaining the pathophysiological mechanisms of WAT dysfunction induced by obstructive sleep apnea.

Evaluation of sleep position shifts in patients with obstructive sleep apnea syndrome with the use of a mandibular advancement device

Background

The aim of this study was to evaluate position shifts during sleep of patients with obstructive sleep apnea (OSA) syndrome both with and without the use of a mandibular advancement device (MAD).

Methods

In total, 73 adult Caucasian patients diagnosed with obstructive sleep apnea syndrome confirmed by polysomnography were retrospectively enrolled. Inclusion criteria were as follows: age >20 years, body mass index <34 kg/m2, polysomnographic diagnosis of OSA, non-smoker, absence of comorbidities at diagnosis, and treatment with a MAD. Two polysomnographic monitoring were performed: one at the time of diagnosis (T0) and another after 3 months of treatment (T1). The parameters evaluated were the apnea-hypopnea index, oxygen desaturation index, the total number of position shifts, and position shift index (number of shifts per hour). Since the variables failed the normality test, the Wilcoxon test was performed to analyze the correlation between the mean of polysomnographic parameters at T0 and T1. The difference between the T1 and T0 values for each variable was evaluated using Spearman's rho correlation test. Statistical significance was set at p < 0.05.

Results and conclusions

All the parameters, including respiratory and positional measures, were significantly reduced after the use of a MAD compared to the beginning. Spearman's correlation test revealed a relationship between the total number of sleep position shifts and the sleep position shift index with the oxygen desaturation index. However, no significant correlation was observed between the apnea-hypopnea index and the positional values.

Is there an association between cognitive impairment and urinary adrenaline, norepinephrine, gamma-aminobutyric acid, and taurine levels in children with obstructive sleep apnea?: A case control study

BACKGROUND

Children with obstructive sleep apnea (OSA) can develop cognitive impairments. Urinary adrenaline (EPI), norepinephrine (NE) and gamma-aminobutyric acid (GABA) are elevated, and taurine is decreased in children with OSA. The purpose of this study was to investigate the above-mentioned neurotransmitter levels in children with and without OSA, and explore their association with OSA-related cognitive impairments.

METHODS

Children underwent overnight polysomnography (PSG) for habitual snoring or mouth breathing in the pediatric sleep center from February 2023 to February 2024, as well as a group of healthy controls were enrolled in this study. Pediatric Quality of Life Inventory (PedsQL) and Child Behavior Checklist (CBCL) were used to evaluate the cognitive function of these children. Morning urine samples were collected to measure the urinary neurotransmitter levels.

RESULTS

This study recruited 74 children with OSA, 30 children with primary snoring (PS) and 16 healthy controls. In the comparison of PedsQL scores, social function (85(75, 100)), school function (65.88 ± 18.52), and total scores (74.15 ± 12.74) of OSA group were significantly lower than that of non-OSA group (P < 0.05); OSA group also exhibited increased withdrawn (1 (0, 2)) and attention problems (2 (1, 5)) scores in CBCL than non-OSA group (P < 0.05). A total of 39 cases in the OSA group (PedsQL total score below 77.42) were considered to have mild cognitive impairment (MCI), who had higher urinary EPI (190.68 ± 38.77 ng/ml) and lower taurine (432.20 ± 53.52 ng/ml) levels than both PS and OSA without MCI groups (P < 0.001). Logistic regression analysis showed that high levels of urinary NE (OR = 1.027, 95%CI: 1.002 ~ 1.052) and low levels of taurine (OR = 0.982, 95%CI: 0.969 ~ 0.995) are significantly associated with cognitive impairment in children with OSA, and their combination has a larger area under the curve (0.695) for prediction, with a sensitivity of 64.1% and specificity of 68.6% (P = 0.004).

CONCLUSIONS

Children with OSA presented impaired cognitive functions such as school, social function deficits and attention problems. Measuring urinary EPI and taurine levels may contribute to the prediction of OSA-related cognitive impairments.

Predictors and Prevalence of Severe Obstructive Sleep Apnea: A Cross-Sectional Study in Erbil, Kurdistan Region, Iraq

Background Obstructive sleep apnea (OSA) is a common sleep disorder that's characterized by episodes of a complete or partial collapse of the upper airway with an associated decrease in oxygen saturation or arousal from sleep. According to the American Academy of Sleep Medicine (AASM), OSA is categorized based on polysomnography findings into mild, moderate, and severe. Objectives This study aims at determining the prevalence of the severities of OSA in Erbil, Kurdistan Region of Iraq, as well as discovering the predictors for severe OSA. Methods This was a cross-sectional study that was carried out from December 2021 to July 2023 on patients displaying OSA symptoms in a sleep study section of a private clinic in Erbil, Kurdistan Region of Iraq. A detailed questionnaire was designed to collect the data, and IBM SPSS Statistics for Windows, Version 26 (Released 2019; IBM Corp., Armonk, New York, United States) was used to analyze it. The polysomnography device used for the diagnosis of OSA was a Philips Respironics Alice NightOne home device, and Philips Respironics Sleepware G3 (Koninklijke Philips N.V., Amsterdam, Netherlands) was used to analyze the sleep data. Results A sample size of 328 OSA cases was analyzed. The results revealed a prevalence of 47% (155) for severe OSA. Apnea-hypopnea index (AHI) was negatively correlated with lowest and average oxygen saturation, while it was positively correlated with time spent with oxygen saturation under 89%, body mass index (BMI), and weight of the participants. Furthermore, stepwise multiple regression tests revealed BMI, age, gender, and heart failure as independent predictors for AHI. Conclusion This study highlights the links between OSA and various chronic health conditions. Furthermore, it underscores the importance of factors like age, obesity, and gender in influencing OSA severity. The identification of predictors for OSA severity can assist in risk assessment and personalized interventions.

Prevalence of obstructive sleep apnea and its associated factors in primary health care in Morocco

OBJECTIVE

Obstructive sleep apnea is a common respiratory disorder that is still underdiagnosed in Morocco. This study aims to determine the prevalence of obstructive sleep apnea and its associated factors in primary healthcare.

METHODS

In this cross-sectional study, 815 adults aged 18 years and older consulting in the primary health care services in Marrakech, Morocco, were included. We evaluated the risk of obstructive sleep apnea syndrome using the modified STOP-BANG questionnaire.

RESULTS

The prevalence of the high risk of obstructive sleep apnea in our sample is 24.8% (CI 95%: 21.7 - 27.6%). The variables independently associated with the high suspicion of obstructive sleep apnea were: gender male (p = 0.001), age ≥ 45 years (p = 0.001), high blood pressure (p = 0.005), hyperlipidemia (p = 0.042), daytime sleepiness (p = 0.003), snoring (p = 0.001), tiredness (p = 0.001) and mandibular retrognathia (p = 0.025).

CONCLUSION

This survey revealed a significant prevalence of obstructive sleep apnea in Morocco. Therefore, we propose to generalize the screening of obstructive sleep apnea in hypertensive patients who report symptoms including daytime sleepiness, snoring, nocturnal choking, and tiredness that are unexplained by other known factors.

Obstructive Sleep Apnea and Serotoninergic Signalling Pathway: Pathomechanism and Therapeutic Potential

Obstructive Sleep Apnea (OSA) is a disorder characterized by repeated upper airway collapse during sleep, leading to apneas and/or hypopneas, with associated symptoms like intermittent hypoxia and sleep fragmentation. One of the agents contributing to OSA occurrence and development seems to be serotonin (5-HT). Currently, the research focuses on establishing and interlinking OSA pathogenesis and the severity of the disease on the molecular neurotransmitter omnipresent in the human body-serotonin, its pathway, products, receptors, drugs affecting the levels of serotonin, or genetic predisposition. The 5-HT system is associated with numerous physiological processes such as digestion, circulation, sleep, respiration, and muscle tone-all of which are considered factors promoting and influencing the course of OSA because of correlations with comorbid conditions. Comorbidities include obesity, physiological and behavioral disorders as well as cardiovascular diseases. Additionally, both serotonin imbalance and OSA are connected with psychiatric comorbidities, such as depression, anxiety, or cognitive dysfunction. Pharmacological agents that target 5-HT receptors have shown varying degrees of efficacy in reducing the Apnea-Hypopnea Index and improving OSA symptoms. The potential role of the 5-HT signaling pathway in modulating OSA provides a promising avenue for new therapeutic interventions that could accompany the primary treatment of OSA-continuous positive airway pressure. Thus, this review aims to elucidate the complex role of 5-HT and its regulatory mechanisms in OSA pathophysiology, evaluating its potential as a therapeutic target. We also summarize the relationship between 5-HT signaling and various physiological functions, as well as its correlations with comorbid conditions.

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.

Craniofacial morphology in Obstructive Sleep Apnea patients

Background

To evaluate the correlation between cephalometric skeletal parameters and Obstructive Sleep Apnea syndrome (OSAs) severity, in adult patients with OSAs.

Material and Methods

One hundred patients (94 males,6 females mean age 59,3) with diagnosis of OSAs were retrospectively enrolled. Each patient received Home Sleep Apnea Testing (HSAT) and latero-lateral radiograph. Eight cephalometric parameters (cranial deflection angle, saddle angle, articular angle, divergence angle, cranial base angle, skull base length, mandibular length, maxilla length) were analyzed and then related to Apnea/Hypopnea Index (AHI) and to the Oxygen Desaturation Index (ODI), recorded by HSAT. A Spearman's rho correlation test between cephalometric measurements and HSAT indices was performed. Statistical significance was set at p< 0.05.

Results

A negative statistically significant correlation was found between mandibular length (Condilion-Gnathion distance) and AHI (rho= -0,2022; p<0,05) and between maxilla length (Ans-Pns) and AHI (rho= -0,2984; p<0,01) and ODI (rho= -0,2443; p<0,05). A statistically significant correlation was also observed between the divergence angle (S-N^Go-Me) and AHI (rho=0,2263; p<0,05) and between cranial deflection angle (Fh^NBa) and AHI (rho=0,2212; p<0,05) and ODI (rho=0,1970; p<0,05).

Conclusions

The OSAs severity may be related to certain predisposing features in craniofacial morphology, such as maxillary and mandibular length, divergence and cranial deflection. Key words:OSAs, Home Sleep Apnea Testing, AHI, ODI, Cephalometry, Airway.

International Consensus Statement on Obstructive Sleep Apnea

BACKGROUND

Evaluation and interpretation of the literature on obstructive sleep apnea (OSA) allows for consolidation and determination of the key factors important for clinical management of the adult OSA patient. Toward this goal, an international collaborative of multidisciplinary experts in sleep apnea evaluation and treatment have produced the International Consensus statement on Obstructive Sleep Apnea (ICS:OSA).

METHODS

Using previously defined methodology, focal topics in OSA were assigned as literature review (LR), evidence-based review (EBR), or evidence-based review with recommendations (EBR-R) formats. Each topic incorporated the available and relevant evidence which was summarized and graded on study quality. Each topic and section underwent iterative review and the ICS:OSA was created and reviewed by all authors for consensus.

RESULTS

The ICS:OSA addresses OSA syndrome definitions, pathophysiology, epidemiology, risk factors for disease, screening methods, diagnostic testing types, multiple treatment modalities, and effects of OSA treatment on multiple OSA-associated comorbidities. Specific focus on outcomes with positive airway pressure (PAP) and surgical treatments were evaluated.

CONCLUSION

This review of the literature consolidates the available knowledge and identifies the limitations of the current evidence on OSA. This effort aims to create a resource for OSA evidence-based practice and identify future research needs. Knowledge gaps and research opportunities include improving the metrics of OSA disease, determining the optimal OSA screening paradigms, developing strategies for PAP adherence and longitudinal care, enhancing selection of PAP alternatives and surgery, understanding health risk outcomes, and translating evidence into individualized approaches to therapy.

Oxygen desaturation index, lowest arterial oxygen saturation and time spent below 90% oxygen saturation as diagnostic markers for obstructive sleep apnea

BACKGROUND

Obstructive sleep apnea (OSA) syndrome is associated with a high mortality, and blood oxygen indexes play an important role in evaluating this disease. The objective of this study was to explore the value of blood oxygen indexes, including minimum oxygen saturation (LSpO2), oxygen reduction index (ODI) and time spent with oxygen saturation below 90% (TS 90%), as diagnostic markers for OSA syndrome.

METHODS

In this retrospective study, 320 patients with OSA treated in Ningbo First Hospital from June 2018 to June 2021 were included and divided into mild, moderate, and severe groups according to the severity of the condition (n = 104, 92, and 124, respectively). The blood oxygen indexes as well as the apnea-hypopnea index (AHI) were compared. The Spearman correlation analysis was performed to explore the relationship between the parameters. Receiver operating characteristic curves were generated to evaluate the diagnostic value of the blood oxygen indexes for OSA syndrome.

RESULTS

There were significant differences in body weight, body mass index, and blood pressure before and after sleep among the groups (P < 0.05). LSpO2 levels followed a pattern with the severe group showing the lowest values, followed by the moderate group, and then the mild group, whereas ODI and TS 90% levels showed the opposite (P < 0.05). Spearman correlation analysis showed that AHI, ODI, TS 90% were positively correlated with severity of OSA, whereas LSpO2 was negatively correlated with severity of OSA. ODI showed a high diagnostic value for OSA (area under curve (AUC) = 0.823, 95% CI: 0.730-0.917). TS 90% showed a high diagnostic value for OSA (AUC = 0.872, 95% CI: 0.794-0.950). LSpO2 showed high accuracy in diagnostic value for OSA (AUC = 0.716, 95% CI: 0.596-0.835). The combination of the 3 indexes demonstrated a high diagnostic value for OSA (AUC = 0.939, 95% CI: 0.890-0.989). The diagnostic value of the combined signature was found to be significantly higher compared to the value of individual indexes (P < 0.05).

CONCLUSION

The evaluation of the severity of OSA should not rely solely on a single observation index, but rather on a combination of ODI, LSpO2 and TS 90%. This combined diagnostic signature can provide a more comprehensive assessment of the patient's condition and serve as an alternative diagnostic basis to ensure timely diagnosis and appropriate clinical treatment for OSA.

Association between Serum Cystatin C levels and long‐term cardiovascular outcomes and all-cause mortality in older patients with obstructive sleep apnea

Background and Aims: To investigate the association between obstructive sleep apnea (OSA) severity and baseline serum cystatin C (Cys-C) concentration and to explore the association between baseline serum Cys-C and long-term cardiovascular outcomes and mortality in older patients with OSA.

Methods: Between January 2015 and October 2017, a total of 1107 consecutive eligible older patients (≥60 years) with OSA were included in this multicenter, prospective cohort study, and baseline demographics, clinical characteristics, sleep parameters, and follow-up outcomes were collected. Participants were divided into different groups based on baseline serum Cys-C levels. The primary end point was major adverse cardiovascular events (MACE) and the secondary end point was all-cause mortality. The correlation between OSA severity and baseline serum Cys-C was evaluated by Spearman correlation analysis. Multivariate Cox regression was used to analyze the association between Cys-C and the incidence of MACE and mortality.

Results: Participants included 672 men and 435 women, with a median age of 66 (range, 60–96) years. At baseline, apnea–hypopnea index (AHI) (r = 0.128, p &lt; 0.05), oxygen desaturation index (ODI) (r = 0.116, p &lt; 0.05), and the lowest pulse oxygen saturation (LSpO2) (r = −0.097, p &lt; 0.05) were correlated with serum Cys-C concentration. During the median follow-up period of 42 months, 97 patients (8.8%) experienced MACE and 40 patients (3.6%) experienced death. The association between serum Cys-C levels and the risk of MACE and all-cause mortality was slow rising shaped. The multivariable Cox regression analysis showed patients with a serum Cys-C concentration of ≥1.14 mg/L had higher risks of MACE (HR = 5.30, 95% CI: 2.28–12.30, p &lt; 0.05) and all-cause mortality (HR = 9.66, 95% CI: 2.09–44.72, p &lt; 0.05) compared with patients with serum Cys-C of ≤0.81 mg/L in older patients with OSA. The receiver-operating characteristic curve showed baseline serum Cys-C levels exhibited moderately capable of identifying patients with a long-term risk of clinical adverse events (MACE and mortality).

Conclusion: OSA severity was positively correlated with serum Cys-C concentration. High levels of Cys-C were independently associated with increased risks of MACE and all-cause mortality in older patients with OSA, suggesting that lowering Cys-C levels should be considered as a therapeutic target, and monitoring serum Cys-C may be beneficial to the favorable prognosis of older patients with OSA.

Review of the Management of Obstructive Sleep Apnea and Pharmacological Symptom Management

Nearly a billion adults around the world are affected by a disease that is characterized by upper airway collapse while sleeping called obstructive sleep apnea or OSA. The progression and lasting effects of untreated OSA include an increased risk of diabetes mellitus, hypertension, stroke, and heart failure. There is often a decrease in quality-of-life scores and an increased rate of mortality in these patients. The most common and effective treatments for OSA include continuous positive airway pressure (CPAP), surgical treatment, behavior modification, changes in lifestyle, and mandibular advancement devices. There are currently no pharmacological options approved for the standard treatment of OSA. There are, however, some pharmacological treatments for daytime sleepiness caused by OSA. Identifying and treating obstructive sleep apnea early is important to reduce the risks of future complications.

Obstructive Sleep Apnea in Adults: What Primary Care Physicians Need to Know

Obstructive sleep apnea (OSA) remains a prominent disease state characterized as the recurrent collapse of the upper airway while sleeping and is estimated to plague 936 million adults globally. Although the initial clinical presentation of OSA appears harmless, it increases the risk of cardiovascular diseases such as heart failure, stroke, and hypertension; metabolic disorders; and an overall decrease in quality of life, in addition to increasing mortality. Current treatment of OSA includes lifestyle changes, behavioral modification, mandibular advancement devices, surgical treatment, and continuous positive airway pressure, which remains the gold standard. It is crucial to identify OSA early on and initiate treatment to mitigate the adverse health risks it imposes. This review will discuss the pathophysiology, epidemiology, management strategies, and medical treatment of OSA.

Metabolic syndrome in non-obese patients with OSA: learning points of a cross-sectional study from a tertiary care hospital in Central India

STUDY OBJECTIVES

Obesity is often considered mandatory for the diagnosis of Metabolic Syndrome (MS). Data on the prevalence of MS in non-obese patients with Obstructive Sleep Apnea (OSA) is scarce. This study was aimed to determine the prevalence of MS in non-obese patients with OSA.

METHODOLOGY

All consecutively diagnosed patients with OSA between October 2018 and November 2019 were screened for metabolic syndrome. Patients with OSA and BMI < 25 kg/m² (NOOSA) vs BMI > 25 kg/m² (obese OSA) were compared. Lean waist NOOSA was defined as BMI < 25 kg/m² and WC < 80 cm (32 in.) for women or < 90 cm (36 in.) for men.

RESULTS

During the study period, 502 patients were diagnosed with OSA. MS was observed in 35% of patients with NOOSA compared to obese patients with OSA (79%). In the NOOSA group, hypertension, impaired fasting glucose, diabetes mellitus and dyslipidemia were observed in 65, 48, 14 and 61% respectively and all of these parameters were significantly more common in the obese group (p < 0.001). Parameters of OSA severity (apnea-hypopnea index or AHI, time spent below 90% saturated or T90, and nadir oxygen) were significantly more severe in the obese group with OSA. Approximately 83% of patients in the NOOSA group had at least two metabolic risk factors, compared to the obese OSA group, in which 95% had two or more metabolic risk factors. Sixty-four percent of patients with NOOSA with lean waist had at least two metabolic risk factors. At BMI cut-offs of < 25, < 27 and < 30 kg/m2; 35, 46 and 57% of patients with OSA respectively had metabolic syndrome.

CONCLUSION

Metabolic syndrome was observed in approximately one in three patients with OSA and BMI < 25 kg/m². Approximately two of every three lean waist non-obese patients with OSA had at least two markers of metabolic syndrome. The role of OSA in the development of metabolic syndrome in non-obese individuals needs further exploration.

Effect of mandibular advancement device treatment on HIF-1α, EPO and VEGF in the myocardium of obstructive sleep apnea-hypopnea syndrome rabbits

The aim of this study was to investigate the effects of mandibular advancement device (MAD) therapy for obstructive sleep apnea-hypopnea syndrome (OSAHS) on hypoxia-inducible factor-1α (HIF-1α), erythropoietin (EPO) and vascular endothelial growth factor (VEGF) in myocardial tissue. New Zealand rabbits were used to develop OSAHS and MAD models. Cone beam computed tomography (CBCT) of the upper airway and polysomnography (PSG) recordings were performed with the animals in the supine position. All of the animals were induced to sleep in a supine position for 4-6 h each day and were observed continuously for 8 weeks. The myocardial tissue of the three groups was dissected to measure the expression of HIF-1α, EPO and VEGF. The results showed that there was higher expression of HIF-1α, EPO and VEGF in the OSAHS group than those in the MAD and control groups. MAD treatment significantly downregulated the expression of HIF-1α, EPO and VEGF in the OSAHS animals. We concluded that MAD treatment could significantly downregulate the increased expression of HIF-1α, EPO and VEGF in OSAHS rabbits, improving their myocardial function.