non-OSA Group Research Articles

Pro-inflammatory markers in patients with obstructive sleep apnea and the effect of Continuous Positive Airway Pressure therapy.

ObjectivesTo evaluate the association of obstructive sleep apnea (OSA) with high-sensitivity C-reactive protein (CRP) and fibrinogen levels and to assess the effect of short-term therapy using continuous positive airway pressure (CPAP).Material and MethodsA prospective, open-label, controlled trial was conducted among clinically referred patients at risk for OSA undergoing diagnostic polysomnography (PSG). After PSG, the patients were divided into 3 groups: OSA treatment group (TG) (n=21), untreated OSA group (UOG) (n=19), and non-OSA healthy control group (HCG) (n=24). CRP and fibrinogen levels were measured at baseline and one month after treatment. Repeated-measures (RM) ANOVA and ANCOVA were used to compare changes in CRP and fibrinogen levels among the three groups by analyzing between-subject and within-subject effects as functions of time and adjusting for significant covariates.ResultsAt baseline, OSA subjects had significantly higher CRP [t(52.37)=-2.46, p=0.02)] and fibrinogen levels [t(57)=-2.00, p=0.05)] than HCG subjects. No significant differences in CRP levels [(F(2,58)=2.29, p=0.11)] or fibrinogen levels [(F(2, 58)=1.28, p=0.29)] emerged between TG and HCG subjects after adjusting for the pretest levels.ConclusionCPAP therapy for one month does not affect CRP and fibrinogen levels among moderate-to-severe OSA patients. However, OSA is associated with elevated levels of these inflammatory biomarkers.

Association of healthy lifestyle with risk of obstructive sleep apnea: a cross-sectional study

BackgroundNo studies investigated the whole effect of modifiable lifestyle factors on OSA risk. This study aimed to examine the individual and combined effects of lifestyle factors on OSA risk among Chinese adults.MethodsThis cross-sectional study included 9733 participants aged 35 to 74 years from the baseline survey of Guangzhou Heart Study. OSA was evaluated by Berlin Questionnaire. The healthy lifestyle score (HLS), representing the overall effect of lifestyles, was derived from seven lifestyle factors: active smoking, passive smoking, alcohol, diet, waist-hip ratio, leisure-time physical activity, and mental status. Odds ratio (OR) with 95% confidence interval (CI) was calculated using the multivariate logistic regression model.Results8107 participants were divided into the non-OSA group and 1626 participants into the OSA group. No passive smoking (OR 0.83, 95% CI 0.74–0.94), healthy waist-hip ratio (OR 0.67, 95% CI 0.58–0.77) and healthy mental status (OR 0.45, 95% CI 0. 29–0.73) were associated with a reduced risk of OSA after adjusting for confounders, while others not. Participants with higher HLS were negatively associated with OSA risk (P-trend < 0.001). In comparison to the participants with 0–3 HLS, the OR for participants with 4, 5, 6, and 7 HLS was 0.68 (95% CI 0.56–0.84), 0.71 (95% CI 0.59–0.86), 0.62 (95% CI 0.51–0.76) and 0.49 (95% CI 0.37–0.65) after adjusting for confounders. Every 1-score increment of HLS was associated with a 13% lower risk of OSA.ConclusionsThe results suggest that HLS reflecting the combined effect of multiple-dimensional lifestyle factors was inversely associated with OSA risk. Preventive strategies integrating multiple lifestyle factors may provide a more feasible approach for OSA prevention.

Task-dependent neural control of regions within human genioglossus.

Anatomical and imaging evidence suggests neural control of oblique and horizontal compartments of the genioglossus differs. However, neurophysiological evidence for differential control remains elusive. This study aimed to determine whether there are differences in neural drive to the oblique and horizontal regions of the genioglossus during swallowing and tongue protrusion. Adult participants (n = 63; 48 M) were recruited from a sleep clinic; 41 had obstructive sleep apnea (OSA: 34 M, 8 F). Electromyographic (EMG) was recorded at rest (awake, supine) using four intramuscular fine-wire electrodes inserted percutaneously into the anterior oblique, posterior oblique, anterior horizontal, and posterior horizontal genioglossus. Epiglottic pressure and nasal airflow were also measured. During swallowing, two distinct EMG patterns were observed - a monophasic response (single EMG peak) and a biphasic response (2 bursts of EMG). Peak EMG and timing of the peak relative to epiglottic pressure were significantly different between patterns (linear mixed models, P < 0.001). Monophasic activation was more likely in the horizontal than oblique region during swallowing (OR = 6.83, CI = 3.46-13.53, P < 0.001). In contrast, during tongue protrusion, activation patterns and EMG magnitude were not different between regions. There were no systematic differences in EMG patterns during swallowing or tongue protrusion between OSA and non-OSA groups. These findings provide evidence for functional differences in the motoneuronal output to the oblique and horizontal compartments, enabling differential task-specific drive. Given this, it is important to identify the compartment from which EMG is acquired. We propose that the EMG patterns during swallowing may be used to identify the compartment where a recording electrode is located.NEW & NOTEWORTHY During swallowing, we observed two distinct, stereotyped muscle activation patterns that define the horizontal (monophasic, maximal EMG) and oblique (biphasic, submaximal EMG) neuromuscular compartments of genioglossus. In contrast, volitional tongue protrusions produced uniform activation across compartments. This provides evidence for task-dependent, functionally discrete neuromuscular control of the oblique and horizontal compartments of genioglossus. The magnitude and temporal patterning of genioglossus EMG during swallowing may help guide electrode placement in tongue EMG studies.

Obstructive sleep apnea in hypothyroidism.

Obstructive sleep apnea (OSA) and hypothyroidism are closely linked as hypothyroidism has been shown to lead to the development of OSA through multiple mechanisms. With the changing lifestyle patterns worldwide and increased prevalence of obesity, the burden of OSA has substantially increased. The association of OSA with hypothyroidism is essential to establish. If identified early, treatment of OSA and associated hypothyroidism can be done timely to minimize the potential harmful complications of OSA on all aspects of the patient's health. This study was done to find out the prevalence of OSA in hypothyroidism patients. It was a cross-sectional study, done over a period of 1 year in a tertiary care hospital. A total of 100 hypothyroidism patients were enrolled after taking written consent. All patients were subjected to STOP-Bang questionnaire and patient falling in intermediate-high risk (score3-8), were taken for overnight polysomnography to confirm the diagnosis of OSA (AHI ≥5). The Statistical Package for the Social Sciences version 21.0 statistical analysis software. Out of 100 patients, who underwent polysomnography, 74 (74%) cases had OSA (AHI ≥5). Out of total 74 OSA cases, 29 (39.2%) cases had mild OSA (AHI 5-14), 15 (20.3%) cases had moderate OSA (AHI 15-30), and 30 (40.5%) cases had severe OSA. The age of the study population ranged between 24 and 78 years and the mean age was 58.28 ± 11.22 years. The mean age of the patients in the OSA group (59.27 ± 11.17 years) was higher than the non-OSA group (55.46 ± 11.09 years). Majority (64%) of our cases were male, and the proportion of males was found to be higher than females in both the groups (OSA/non-OSA). The body mass index (BMI) of the OSA group was found to be statistically higher as compared to that of the non-OSA group (P = 0.040). The BMI was found to be higher in severe OSA, but it was not statistically significant (P = 0.128). The mean value of FT4 was lower and thyroid-stimulating hormone (TSH) was higher in the OSA group as compared with the non-OSA group. However, no significant association was found between FT4 and TSH values in both the groups. Out of 100 cases, 41 patients were treatment naïve with mean TSH value of 13.1 ± 7 and 59 were on treatment with mean TSH of 8.3 ± 4. Treatment-naïve patients had a statistically higher number (85.3%) of OSA cases in comparison to patients on treatment (66.1) (P = 0.030). Prevalence of OSA is quite high in hypothyroidism. Patients with hypothyroidism should be screened for OSA for early diagnosis, especially in individuals with higher BMI. Treatment of hypothyroidism reduces the prevalence of OSA.

Prevalence of obstructive sleep apnea in a sample of Egyptian railway drivers

Background There are scanty international and even no Egyptian studies addressing the prevalence of obstructive sleep apnea syndrome (OSAS) in railway drivers with an expected high risk of accidents. Thus, it is worth studying and assessing the prevalence and predictors of OSAS among Egyptian railway drivers. Patients and methods This prospective cross-sectional screening study was conducted on 160 Egyptian railway drivers. They were subjected to medical history taking and examination, anthropometric measurements, oxygen saturation (SpO2) by oximetry, arterial blood gases, Friedman obstructive sleep apnea–hypopnea syndrome score measurement, and Arabic version of both Berlin and STOP BANG questionnaires. Then, limited night polysomnography (PSG) was performed in high-risk patients. Finally, full channel PSG was done for positive limited night PSG. Results The prevalence of sleep apnea among the studied cases was 4.22%. There was high statistically significant difference between the non-OSAS group and the OSAS group regarding age less than or equal to 49 years [odds ratio (OR)=11.364], witnessed apneas during sleep (OR=175), weight in kg more than 95 (OR=13.00), PaO2 less than or equal to 88 (OR=31.0), PaCO2 more than 39 (OR=31.0), and average SPO2 less than or equal to 88 (OR=34.0). Regarding parameters of limited night PSG, the apnea–hypopnea index cutoff point was more than or equal to 5 with an area under the curve (AUC) of 100%, O2 desaturation index cutoff point was more than 17.2 with an AUC of 100%; lastly, the average SPO2 cutoff point was less than or equal to 88% with an AUC of 76.4%. Conclusion This study highlights for the first time that the prevalence of OSAS was 4.2% in a sample of Egyptian railway drivers. Our results further point out that weight, neck circumference, systolic blood pressure, PaO2, and PaCO2 are the most useful predictors of suspecting OSAS. Also, parameters of limited PSG are considered a useful tool in confirming suspected patients with OSAS.

Analysis of Salivary Microbiome and Its Association With Periodontitis in Patients With Obstructive Sleep Apnea.

ObjectivesThis study aimed to analyze the periodontal conditions of patients with obstructive sleep apnea (OSA) in relation to the salivary microbiome.Materials and MethodsIn total, 54 male adults (27 with OSA, 27 controls) completed this cross-sectional study. All participants were monitored by overnight polysomnography (PSG) and underwent full-mouth periodontal examination. Saliva samples were then collected, and the microbial 16S ribosomal RNA gene was sequenced. The data were analyzed to determine the microbial distribution and the community structure of the two groups.ResultsDemonstrated by alpha and beta diversity, the OSA group had a lower microbial richness and a lower observed species than the controls. There was no significant difference in the microbial species diversity or evenness between the OSA and the non-OSA groups. The OSA group had fewer operational taxonomic units (OTUs), and the distribution of microbiome showed that several gram-positive bacteria had higher abundance in the OSA group. As for periodontal pathogens, the relative abundance of Prevotella was significantly increased in the OSA group. No significant difference was observed in the relative abundance of other pathogens at either the genus or species level.ConclusionsThe salivary microbial community structure was altered in patients with OSA in terms of species richness and trans-habitat diversity, along with an increase in Prevotella, a specific periodontal pathogen. These findings might explain the high prevalence of periodontitis in OSA patients.

한국 아동의 비타민 D 수치와 폐쇄성 수면 무호흡증 사이의 상관 관계

Background and Objectives: To evaluate relationship between vitamin D and severity of obstructive sleep apnea (OSA) in Korean children. Materials and Methods: This study was conducted on children aged 5 to 17 years who had polysomnography and blood 25-hydroxyvitamin D (25(OH)D) measurements from January 2015 to July 2018 in our Medical Center. Apnea hypopnea index (AHI) 1 or higher was considered to be an OSA patient, and obesity was defined when the body mass index (BMI) was 95% or more of each age and gender. Vitamin D level was checked through 25(OH)D in blood. Results: Of the total 109 children included in the study, the mean blood concentration of 25(OH)D was 19.5±7.1 ng/mL and AHI was 5.4±15.8 /h. Sixty-five children (59.6%) were Vitamin D deficient. In bivariate correlation analysis, 25(OH)D level and BMI z-score (r=–0.24, p=0.01), AHI (r=–0.22, p=0.02) showed a statistically significant negative correlation. Forty children were obese, and the 25(OH)D in the obese group was statistically significantly lower (p=0.08). In the obese group, 25(OH)D was not statistically correlated with AHI, but obstructive portion of AHI obstructive showed a statistically negative correlation (r=–0.36 , p=0.02). Compared to the non-OSA group, the OSA group had a statistically significantly lower 25(OH)D (p=0.04). Conclusions: Vitamin D level was lower in obese children and children with OSA. There was a correlation between the severity of OSA and vitamin D deficiency. (J Clinical Otolaryngol 2021;32:221-227)

Obstructive sleep apnoea and 12-month weight loss in adults with class 3 obesity attending a multidisciplinary weight management program

BackgroundAlthough there is a strong association between obesity and obstructive sleep apnoea (OSA), the effects of OSA and CPAP therapy on weight loss are less well known. The aim of this study in adults with class 3 obesity attending a multidisciplinary weight management program was to assess the relationship between OSA and CPAP usage, and 12-month weight change.MethodsA retrospective cohort study of all patients commencing an intensive multidisciplinary publicly funded weight management program in Sydney, Australia, between March 2018 and March 2019. OSA was diagnosed using laboratory overnight sleep studies. Demographic and clinical data, and use of CPAP therapy was collected at baseline and 12 months. CPAP use was confirmed if used ≥4 h on average per night on download.ResultsOf the 178 patients who joined the program, 111 (62.4 %) completed 12 months in the program. At baseline, 63.1 % (n=70) of patients had OSA, of whom 54.3 % (n=38) were using CPAP. The non-OSA group had more females compared to the OSA with CPAP group and OSA without CPAP group (90.2 % vs. 57.9 % and 62.5 %, respectively; p=0.003), but there were no significant baseline differences in BMI (50.4±9.3 vs. 52.1±8.7 and 50.3±9.5 kg/m2, respectively; p=0.636). There was significant weight loss across all three groups at 12 months. However, there were no statistically significant differences across groups in the percentage of body weight loss (OSA with CPAP: 6.3±5.6 %, OSA without CPAP: 6.8±6.9 %, non-OSA: 7.2±6.5 %; p=0.844), or the proportion of patients who achieved ≥5 % body weight loss (OSA with CPAP: 57.9 %, OSA without CPAP: 59.4 %, non-OSA: 65.9 %; p=0.743). In patients with T2DM, there was a significant reduction in HbA1c from baseline to 12 months (7.8±1.7 % to 7.3±1.4 %, p=0.03), with no difference between groups (p=0.997).ConclusionsThis multidisciplinary weight management program resulted in significant weight loss at 12 months, regardless of OSA diagnosis or CPAP use in adults with class 3 obesity. Larger studies are needed to further investigate the effects of severity of OSA status and CPAP use in weight management programs. Until completed, this study suggests that the focus should remain on implementing lifestyle changes and weight management regardless of OSA status.

Effect of arterial blood bicarbonate (HCO3\u2212) concentration on the accuracy of STOP-Bang questionnaire screening for obstructive sleep apnea

BackgroundTo evaluate the effect of arterial bicarbonate (HCO3−) concentration on the accuracy of STOP-Bang questionnaire (SBQ) screening for obstructive sleep apnea (OSA).MethodsA total of 144 patients with suspected OSA were included. Polysomnograms (PSG) and blood gas analysis were performed, and the Epworth Sleepiness Scale (ESS), STOP-Bang questionnaire, and Berlin questionnaire were completed. The correlation between the arterial HCO3− concentration, apnea hypopnea index (AHI), and other related indicators was analyzed. The scoring results of the ESS, SBQ, and Berlin questionnaire were compared with the PSG results, and the sensitivity and specificity were calculated in the form of a four-cell table. The changes in the sensitivity and specificity of OSA screening after SBQ alone and combined with HCO3− concentration were compared, and ROC curves were drawn.ResultsArterial HCO3− concentration was positively correlated with AHI (r = 0.537, P < 0.001). The ratio of HCO3− concentration ≥ 24.6 mmol/L in the non-OSA group was significantly lower than that in the OSA group (25.0% VS 80.8%, P < 0.001). The sensitivity of the SBQ was higher than that of the ESS (97.5% VS 81.7%, P < 0.001) and the Berlin questionnaire (97.5% VS 79.2%, P < 0.001). There was no statistical significance in the specificity of the three scales (25%, 37.5%, 37.5%). A combined SBQ score ≥ 3 and HCO3− concentration ≥ 24.6 mmol/L showed increased specificity and decreased sensitivity compared with an SBQ score ≥ 3 alone, with a corresponding AUC of 0.771 (P < 0.01) and 0.613 (P > 0.05), respectively.ConclusionThe sensitivity of the SBQ was better than that of the Berlin questionnaire and ESS. After combining arterial blood HCO3− concentration, the SBQ questionnaire increased the specificity of OSA prediction and decreased the sensitivity, which improved the accuracy of screening.

Early corneal and optic nerve changes in a paediatric population affected by obstructive sleep apnea syndrome.

The relation between OSAS and eye diseases is well known in adults, while very few and contradictory data can be found regarding paediatric ages. The aim of this study is to explore the early corneal, macular and optic nerve changes in paediatric patients with OSAS. Prospective study that enrolled children aged ≥ 4years referred to the Paediatric Pneumology Clinic in Verona for suspected obstructive sleep apnoea syndrome (OSAS) and investigated with the overnight respiratory polygraphy. Patients with apnoea-hypopnea index (AHI) > 1 were classified as OSAS, while those with AHI < 1 were classified non-OSAS. All patients underwent comprehensive eye examination including slit lamp, refraction, intraocular pression (Goldman applanation tonometry), corneal tomography (corneal astigmatism, corneal keratometry at the apex, surface asymmetry index, central corneal thickness and thinnest corneal thickness) and optical coherence tomography (central macular thickness, macular volume and retinal nerve fibre layer). Seventy-two children were enrolled in the study. The overall prevalence of OSAS was 48.6%. Statistically significant differences were found between OSAS and non-OSAS group for corneal asymmetry (0.9 ± 0.5 and 0.6 ± 0.3, respectively; p = 0.02), thinnest corneal thickness (551.8 ± 33.9 and 563.7 ± 32.5; p = 0.04), average retinal nerve fibre layer (102.8 ± 10.5µm and 98.1 ± 12.3µm; p = 0.012) and in nasal quadrant (76.2 ± 15.4µm and 66.5 ± 12.6µm; p = 0.0002). A comprehensive eye examination with corneal and optic nerve imaging showed early corneal and optic nerve changes in children newly diagnosed with OSAS. These could be prelude of the known ocular manifestations associated with OSAS in adult patients.

Ultrasound measurement of upper airway related indicators and patients with obstructive sleep apnea hypopnea correlation study of disease severity

Objective:To compare the difference of upper airway anatomy between non-obstructive sleep apnea（OSA） patients and OSA patients, and to analyse the correlation between upper airway anatomy and the disease severity based on the upper airway ultrasound examination. Methods:Eighty-five OSA patients （OSA group） and 36 non-OSA subjects （non-OSA group） who were admitted to the Second Hosipital of Shenzhen from January 2021 to May 2021 were recruited to perform upper airway ultrasound measurement. The airway anatomical parameters were compared and analyzed by t-test. The Spearman correlation analysis was performed on the ultrasound measurement values of OSA patients with the apnea-hypopnea index （AHI） and minimum blood oxygen saturation （ LSaO2）. Results:There were statistically significant differences in BMI, the distance between the soft and hard palate junction and the hyoid bone, the angle between the hard palate and the soft palate, and the angle between the hyoid bone and the hard palate between the OSA group and the non-OSA group（P<0.001，respectively）; For 85 cases of OSA， correlation analysis between the patient's upper airway B-ultrasound measurements and AHI and LSaO2 showed that the distance from the soft and hard palate junction to the mandible, the distance from the soft and hard palate junction to the hyoid bone, the thickness of the tongue（longitudinal section）, and the thickness of the soft palate（longitudinal section）are positively correlated with AHI（r=0.3758, 0.4619, 0.3227, 0.2738, P<0.05, respectively）; the distance from the soft and hard palate to the mandible, the distance from the soft and hard palate to the hyoid bone, the width of tongue（transverse section），and the tongue thickness（longitudinal section） are negatively correlated with LSaO2（r=-0.3566, -0.5470, -0.3168, -0.3098, P<0.05, respectively）; the angle between the hard palate and the soft palate is negatively correlated with AHI（r=-0.2262, P<0.05）; the angle between the hyoid bone and the hard palate is positively correlated with AHI and negatively correlated with LSaO2（r=0.2889, -0.3351, P<0.01）. Conclusion:The upper airway related anatomical parameters based on ultrasound measurement, such as the distance from the soft and hard palate junction to the mandible, the distance from the soft and hard palate junction to the hyoid bone, the angle between the hyoid bone and the hard palate, and the angle between the hard palate and the soft palate, etc.， are associated with the disease severity in OSA patients. The correlation may be used as a potential objective indicator to evaluate the severity of patients with OSA.

Erythropoietin levels in children with obstructive sleep apnea

ObjectiveHigh serum erythropoietin (EPO) levels have been reported in adult patients with obstructive sleep apnea (OSA), however there is a lack of related literature in children with OSA. The main objective of this study was to explore the potential use of EPO as a pediatric OSA biomarker by exploring the relationship between serum EPO levels and the presence of pediatric OSA. Methods and materialsA prospective study was conducted on children (4–12 years old) referred for overnight PSG. Thirty (30) consecutive children with mild. 30 consecutives with moderate, and 30 consecutives with severe OSA (OSA group), as well as 30 consecutive children with AHI≤1 (non-OSA group) were recruited. Morning blood specimens after PSG studies were obtained in order to compare EPO levels. ResultsFinally, 115 children included for analysis. Non-OSA group consisted of 29 children (mean age: 6.93 ± 2.10) and OSA-group of 86 children (mean age: 6.78 ± 2.53). Mean EPO values for the non-OSA and OSA groups were 5.46 ± 2.29 mIU/ml and 8.33 ± 4.10 mIU/ml respectively. OSA-group had significant higher EPO levels than non-OSA (P: 0.01) while EPO levels were significantly correlated with AHI (p < 0.001). ConclusionOur study showed that serum EPO levels of children with OSA are significantly higher than those without OSA and correlate significantly with AHI. These results suggest that EPO may be considered as a biomarker candidate for pediatric OSA. Since this may be the first study on the topic further research is needed.

Assessment of event-related evoked potentials and China-Wechsler intelligence scale for cognitive dysfunction in children with obstructive sleep apnea

ObjectiveTo explore the relationship between obstructive sleep apnea (OSA) and cognitive impairment by combining event-related evoked potentials (ERPs) and China-Wechsler Younger Children Scale (C-WISC) in children with sleep-disordered breathing (SDB) with vs. without OSA. MethodsThis was a retrospective case-control study of all consecutive children (n = 148) with adenoid tonsil hypertrophy between July 2017 and March 2019 at the Hospital. ResultsThe children were divided into the OSA (n = 102) and non-OSA (n = 46) groups. The apnea-hypopnea index (AHI), obstructive apnea index (OAI), and obstructive apnea-hypopnea index (OAHI) in the OSA group were elevated compared with those of the non-OSA group (all P < 0.001). The mean oxygen saturation (SaO2) and SaO2 nadir were lower in the OSA group compared with the non-OSA group (both P < 0.001). The respiratory arousal index (RAI) values in the OSA group were larger than those of the non-OSA group (P < 0.001). The P300 and N100 latencies in the OSA group were longer than those of the non-OSA group (both P < 0.001). Pearson's correlation analysis revealed correlations of the P300 peak latency with full-scale intelligence quotient (FIQ) (P < 0.001 and r = −0.527), verbal intelligence quotient (VIQ) (P < 0.001 and r = −0.448), and performance intelligence quotient (PIQ) (P < 0.001 and r = −0.515). There was a correlation between the N100 peak latency and PIQ (P = 0.026 and r = −0.183). ConclusionERPs, as an objective measurement, might help assess cognitive impairment in children with OSA.

Densely granulated adenoma pattern is associated with an increased risk of obstructive sleep apnea in patients with acromegaly

To explore the prevalence of obstructive sleep apnea (OSA) and the association between the adenomagranulation patterns and OSA in patients with acromegaly. An overnight polysomnography (PSG) assessment was carried out on participants with acromegaly. Resultsclassified participantsinto anon-OSA group, mild to moderate OSA group, and severe OSA group. Morphological and biochemical analyses were performed. Demographic, clinical, biochemical, and polysomnographic data were compared among the three groups. Using logistic regression models, the risk of OSA in acromegalic subjects was estimated. OSA was reported in 36 of 49patients (74%) with acromegaly. Contrasted with the non-OSA group, OSA patients had a larger proportion of the densely granulated (DG) pattern. The OSA groups with DG acromegaly had a smaller maximum tumor diameter and Vol/2 than those with the sparsely granulated (SG) pattern. Furthermore, a higher growth hormone (GH) level (45.0 ± 36.9 vs 18.6 ± 15.8, P = 0.047) and GH index (28.4 ± 13.8 vs 6.6 ± 8.2, P = 0.003) were found in DG acromegaly patients with severe OSA. Additionally, there was a trend toward higher standardized insulin-like growth factor 1 (IGF-1) in patients with DG acromegaly than in those with SG acromegaly in the severe OSA group. After adjusting for potential confounding variables, the DG pattern was correlated with the risk of OSA (OR = 14.84, 95%CI 1.36-162.20, P = 0.027) in patients with acromegaly. The findings indicate that a high prevalence of OSA exists in patientswith acromegaly, and the DG pattern may be a risk factor for OSA in acromegaly.

Effect of Obstructive Sleep Apnea on Bone Mineral Density.

Various studies have suggested that obstructive sleep apnea (OSA) affects bone metabolism. One of the most significant factors is hypoxia which induces certain transcription factors that stimulate bone osteoclastic activity. It also induces respiratory acidosis and oxidative stress which enhances bone resorption. Leptin and melatonin secretions are regulated by the circadian system which is affected due to sleep fragmentation in OSA. Other comorbidities associated with OSA such as vitamin D deficiency, hypogonadism, obesity, and insulin resistance are indirect mechanisms that affect bone mineral density (BMD). This is a prospective case-control study. All patients having symptoms of sleep-related breathing disorder (excluding post-menopausal females or patients with known case of osteoporosis or any other clinical illness which is a direct cause of osteoporosis) attending the Sleep Out Patient Department (OPD) were screened for OSA as per the STOPBANG questionnaire scoring system. Participants having score >2 constituted the final study population and were subjected to the polysomnography test. Participants with an apnea-hypopnea index (AHI) > 5 in polysomnography were considered as cases and those with AHI <5 were considered as controls. Both the groups were then subjected for dual-energy X-ray absorptiometry (DEXA) scan and vitamin D to establish a comparison. Out of 93 participants, 59 were taken as cases (OSA group), whose mean age was 48.02 (±8.435) years, mean body mass index (BMI) was 33.73 (±7.48) kg/m2, mean neck circumference was 37.8 cm (±5.08) as compared with the age, sex, and BMI matched non-OSA control group (n = 34). Mean BMD in the case group was found to be significantly on the lower side as compared with the control group (-2.02 ± 1.09 vs. -1.03 ± 0.97) (P < .001) when compared in Z score, while (0.885 ± 0.535 vs. 0.933 ± 0.616) when compared in g/cm2 (P < .001), with negative correlation between AHI and BMD (r = -0.507, P < .001). Mean vitamin D level in the case group was at a lower level as compared to the control group (21.02 ± 7.27 vs. 24.48 ± 6.92, P < .05), with negative correlation between AHI and serum vitamin D level (P < .001, r = -0.286). OSA affects BMD by various pathophysiologic mechanisms. The AHI is inversely correlated with BMD; that is, with increasing severity of OSA, there is a decrease in BMD.

Obstructive Sleep Apnea Increases the Risk of Perioperative Myocardial Infarction Following Off-Pump Coronary Artery Bypass Grafting.

Background and Aims: The impact of obstructive sleep apnea (OSA) on perioperative myocardial infarction (PMI) following coronary artery bypass grafting (CABG) remains unclear. Off-pump CABG (OPCABG) has become a common practice for CABG in China. The present study investigated mainly the correlation between OSA and PMI following OPCABG.Methods: In this prospective observational single-center study, consecutive eligible patients listed for elective OPCABG underwent cardiorespiratory polygraphy before surgery between January 2019 and June 2020. OSA was defined as an apnea-hypopnea index (AHI) ≥15 events/h. The primary end point was perioperative myocardial infarction (PMI) following OPCABG (type 5 MI).Results: Patients with OSA accounted for 42.2% (62/147) of the cohort. Twenty-four patients (16.3%) met the protocol criteria for PMI: 17 (27.4%) in the OSA group and 7 (8.2%) in the non-OSA group (P = 0.002). Multivariate logistic regression analysis revealed that AHI (OR = 1.115, 95% CI 1.066 to 1.166, P < 0.001), high-sensitivity c-reactive protein (hs-CRP) (OR = 1.080, 95% CI 1.025 to 1.138, P = 0.004), and SYNTAX score (OR = 1.098, 95% CI 1.056 to 1.141, P < 0.001) were associated with PMI incidence. Furthermore, ROC analysis revealed that the AHI (AUC = 0.766, 95% CI 0.689 to 0.832, P < 0.001) and SYNTAX score (AUC = 0.789, 95% CI 0.715 to 0.852, P < 0.001) had predictive value for PMI. In addition, multiple linear regression analysis showed that the AHI was an independent influencing factor of hs-CRP (B = 0.176, 95% CI 0.090 to 0.263, P < 0.001) and the SYNTAX score (B = 0.553, 95% CI 0.397 to 0.709, P < 0.001).Conclusions: OSA was independently associated with a higher incidence of PMI following OPCABG, and the formation of severe coronary atherosclerotic lesions aggravated by an enhanced inflammatory response might be the potential mechanism. The efficacy of CPAP treatment for improving prognosis after CABG remains to be further investigated.

Cardiac imageology changes in patients with mild obstructive sleep apnea without cardiovascular disease.

This study aims to assess changes in cardiac imageology of patients with mild obstructive sleep apnea (OSA) without cardiovascular disease. All enrolled participants underwent polysomnography (PSG). Some participants underwent transthoracic echocardiography, speckle tracking echocardiography, and cardiac-enhanced magnetic resonance imaging (MRI) if they were willing. They were divided into three groups according to PSG results: non-OSA, mild OSA, and moderate-to-severe OSA. Imageology parameters were compared, and the relationship between OSA severity and imageology indices was analyzed by correlation analysis and multiple linear regression. Of the 352 enrolled participants, 274 participants with OSA had an apnea-hypopnea index (AHI) of ≥ 5 (86 mild OSA and 188 moderate-to-severe OSA cases), and 78 participants with non-OSA had an AHI of < 5. Transthoracic echocardiography showed that E/A and E'/A' values were lower in the mild OSA group than in the non-OSA group (1.12 ± 0.37 vs 1.27 ± 0.45 and 0.83 ± 0.33 vs 0.99 ± 0.42, respectively, p < 0.05). The aorta and ascending aorta widths were smaller in the mild OSA group than in the moderate-and-severe OSA groups (27.36 ± 2.87mm vs 28.87 ± 2.95mm and 30.27 ± 3.79mm vs 31.63 ± 3.74mm, respectively, p < 0.05). A regression analysis showed that cardiac function changes in patients with OSA may be related to age, obesity, and OSA severity. Patients with mild OSA without cardiovascular disease displayed changes in cardiac structure and function on transthoracic echocardiography.

Novel proteins associated with chronic intermittent hypoxia and obstructive sleep apnea: From rat model to clinical evidence.

ObjectiveTo screen for obstructive sleep apnea (OSA) biomarkers, isobaric tags for relative and absolute quantitation (iTRAQ)-labeled quantitative proteomics assay was used to identify differentially expressed proteins (DEPs) during chronic intermittent hypoxia (CIH).MethodThe iTRAQ technique was applied to compare DEPs in the serum of a CIH rat model and control group. Biological analysis of DEPs was performed using Gene Ontology and Kyoto Encyclopedia to explore related biological functions and signaling pathways. Enzyme-linked immunosorbent assay (ELISA) was performed to validate their expression in sera from patients with OSA and CIH rats.ResultsTwenty-three DEPs (fold change ≥1.2 or ≤0.833, p<0.05) were identified, and two DEPs (unique peptides>3 and higher coverage) were further verified by ELISA in the CIH rat model and OSA subject: apolipoprotein A-IV (APOA4, p<0.05) and Tubulin alpha-1A chain (TUBA1A, p<0.05). Both groups showed significant differences in the expression levels of DEPs between the CIH and control groups and the severe OSA and non-OSA groups. APOA4 was found to be upregulated and TUBA1A downregulated in both the sera from OSA patients and CIH rats, on comparing proteomics results with clinical results. There were two pathways that involved three DEPs, the mitogen-activated protein kinase (MAPK) signaling pathway (p<0.05) and cytokine-cytokine receptor interaction (p<0.05).ConclusionAPOA4 and TUBA1A may be potential novel biomarkers for CIH and OSA, and may play an important role in the development of OSA complications.

Assessment of obstructive sleep apnea-related sleep fragmentation utilizing deep learning-based sleep staging from photoplethysmography.

Study ObjectivesTo assess the relationship between obstructive sleep apnea (OSA) severity and sleep fragmentation, accurate differentiation between sleep and wakefulness is needed. Sleep staging is usually performed manually using electroencephalography (EEG). This is time-consuming due to complexity of EEG setup and the amount of work in manual scoring. In this study, we aimed to develop an automated deep learning-based solution to assess OSA-related sleep fragmentation based on photoplethysmography (PPG) signal.MethodsA combination of convolutional and recurrent neural networks was used for PPG-based sleep staging. The models were trained using two large clinical datasets from Israel (n = 2149) and Australia (n = 877) and tested separately on three-class (wake/NREM/REM), four-class (wake/N1 + N2/N3/REM), and five-class (wake/N1/N2/N3/REM) classification. The relationship between OSA severity categories and sleep fragmentation was assessed using survival analysis of mean continuous sleep. Overlapping PPG epochs were applied to artificially obtain denser hypnograms for better identification of fragmented sleep.ResultsAutomatic PPG-based sleep staging achieved an accuracy of 83.3% on three-class, 74.1% on four-class, and 68.7% on five-class models. The hazard ratios for decreased mean continuous sleep compared to the non-OSA group obtained with Cox proportional hazards models with 5-s epoch-to-epoch intervals were 1.70, 3.30, and 8.11 for mild, moderate, and severe OSA, respectively. With EEG-based hypnograms scored manually with conventional 30-s epoch-to-epoch intervals, the corresponding hazard ratios were 1.18, 1.78, and 2.90.ConclusionsPPG-based automatic sleep staging can be used to differentiate between OSA severity categories based on sleep continuity. The differences between the OSA severity categories become more apparent when a shorter epoch-to-epoch interval is used.

Sleep apnea, coronary artery calcium density, and cardiovascular events: results from the Multi-Ethnic Study of Atherosclerosis.

Evaluate the association between obstructive sleep apnea (OSA), coronary artery calcium (CAC) density, and cardiovascular events in the Multi-Ethnic Study of Atherosclerosis (MESA). We analyzed 1,041 participants with nonzero CAC scores who had polysomnography and CAC density data from the fifth examination of the Multi-Ethnic Study of Atherosclerosis. OSA was defined as apnea-hypopnea index ≥ 15 events/h. Multivariable linear regression models were used to evaluate the independent association between OSA and CAC density. Additionally, we evaluated the impact of OSA on associations of CAC measures with incident cardiovascular disease events by testing for interaction in Cox proportional hazard regression models. Our analytical sample was 45% female with a mean age of 70.6 +/- 9 years. Of this sample, 36.7% (n = 383/1041) had OSA (apnea-hypopnea index ≥ 15 events/h). OSA was inversely and weakly associated with CAC density (β = -0.09; 95% CI, -0.17 to -0.02; P = .014) and remained significantly associated after controlling for traditional cardiovascular risk factors (β = -0.08; 95% CI, -0.16 to 0; P = .043). However, this inverse association was attenuated after controlling for body mass index (β = -0.05; 95% CI, -0.13 to 0.02; P = .174). The mean follow-up period for cardiovascular disease events was 13.3 +/- 2.8 years. Additionally, exploratory analysis demonstrated that CAC density was independently and inversely associated with cardiovascular disease events only in the non-OSA subgroup (apnea-hypopnea index ≤ 15 events/h) (hazard ratio, 0.509; 95% CI, 0.323-0.801); P = .0035). OSA was associated with lower CAC density, but this association was attenuated by body mass index. Further, increased CAC density was associated with a reduced risk of cardiovascular disease events only in individuals within the non-OSA group in exploratory analysis. Newman SB, Kundel V, Matsuzaki M, etal. Sleep apnea, coronary artery calcium density, and cardiovascular events: results from the Multi-Ethnic Study of Atherosclerosis. J Clin Sleep Med. 2021;17(10):2075-2083.