Mild-moderate Obstructive Sleep Apnea Research Articles

Polysomnographic Phenotype of Positional Obstructive Sleep Apnea

Background and Objectives: Obstructive sleep apnea (OSA) is a prevalent sleep disorder characterized by recurrent upper airway obstruction, leading to disrupted sleep and various health complications. Positional OSA (POSA) refers to patients whose OSA severity is significantly influenced by body position, especially when lying supine. This study aimed to evaluate the polysomnographic characteristics of POSA and non-positional OSA (non-POSA) and to assess their clinical implications.Methods: This retrospective study included patients diagnosed with OSA who underwent type 1 polysomnography. Patients were categorized into POSA and non-POSA groups based on whether their apnea-hypopnea index (AHI) in the supine position was at least twice as high as that in the lateral position. We collected and analyzed clinical and polysomnographic parameters, including AHI, oxygen desaturation index, arousal index, nadir peripheral oxygen saturation (SpO<sub>2</sub>), and sleep position proportions. These were compared across different OSA severity levels—mild, moderate, and severe—to assess differences between the POSA and non-POSA groups.Results: In total, 500 patients with OSA were analyzed, of whom 63.4% were classified as having POSA. Patients with POSA exhibited milder disease severity than those without, with an average AHI of 23.3±15.3/h versus 43.9±27.9/h, respectively, and a higher nadir SpO<sub>2</sub> of 82.8%±6.6% versus 77.1%±9.8%. POSA was more common in patients with mild OSA (76.5%) and moderate OSA (72.8%), while severe OSA cases were predominantly non-POSA (POSA was 47.4%). Moreover, patients with POSA spent significantly more sleep time in the lateral position (43.8%±22.7%) than non-POSA patients (27.2%±28.2%).Conclusion: Patients with POSA generally exhibited milder disease and more favorable polysomnographic profiles than non-POSA patients. POSA is prevalent in mild-to-moderate OSA, and identifying it via polysomnography may inform tailored treatment strategies.

Cone beam computed tomography changes upon oral appliance therapy for adult patients with obstructive sleep apnea: A non-randomized clinical trial.

Obstructive sleep apnea (OSA) is caused by narrowing or obstruction of the airway lumen at single or multiple levels of the airway, starting from the nasal cavity up to the larynx. Oral appliance therapy for the management of OSA is prescribed as an alternative treatment option for patients with mild to moderate OSA who fail to adhere to Continuous Positive Airway Pressure (CPAP) therapy. Treatment with oral appliances addresses the craniofacial deficiencies that cause OSA by providing means to mandibular advancement and palatal expansion, thus opening the airways and potentially preventing airway collapse during sleep. Imaging the upper airway is employed to investigate the narrowing or the obstruction in the airway. Three-dimensional imaging modalities such as cone beam computed tomography (CBCT) allow for detecting obstructions before commencing treatment and for evaluating changes in the upper airway dimensions after treatment. To evaluate the effect of the biomimetic oral appliance therapy (BOAT) device on the airway measurements taken from a CBCT before and after treatment in correlation with the changes in the AHI. A non-randomized clinical trial. About 17 patients with mild-moderate OSA (9 males, 8 females; age, mean [SD]: 45.76 [10.31]) underwent BOAT therapy. Subjects had 2 months of follow-up visits, including examinations for progress and adjustment of the appliances. The mean apnea-hypopnea index (AHI) with no appliance in the mouth before BOAT and after treatment was recorded. The midpalate screw mechanism of the appliance was advanced once per week. The subjects were asked to wear the appliance for 10 to 12 h/d and night. Pre and Post CBCT were taken. Paired T-test was used to analyze the results. The treatment duration was 15.4 ± 6.3 months. Before treatment, at the diagnosis stage, the mean AHI of the sample (n = 17) was 24.0. After treatment, the mean AHI fell by 5% to 22.8% (P = .019), indicating enhanced upper airway functions. Airway measurements from the CBCT were not statistically significant despite improvement in the polysomnographic parameters. CBCT is a valuable tool for airway assessment and the determination of upper airway anatomic risk factors for OSA.

Exploratory Study of Relationship Between Obstructive Sleep Apnea Syndrome and Growth Hormones and Inflammatory Factors in Children

Purpose: In children, obstructive sleep apnea (OSA) is associated with growth hormone level abnormalities and chronic systemic inflammation. This study was performed to investigate the relationship of the degree of OSA with insulin-like growth factor 1 (IGF-1) and inflammatory cytokines in pediatric OSA and the inter-relationship between inflammatory cytokines and growth hormones. Methods: Children with OSA and controls without OSA participated in the study. Information included polysomnography followed by measurement of IGF-1 and inflammatory marker levels. In total, 226 patients aged 2 to 12 years were divided into 4 groups: non-OSA, n = 57 (25.2%); mild OSA, n = 116 (51.3%); moderate OSA, n = 23 (10.2%); and severe OSA, n = 30 (13.3%). Results: Body height was not significantly different among the 4 groups. However, the minimum oxygen saturation and IGF-1 significantly differed among the different OSA groups ( P = .0001 and P = .036, respectively). IGF-1 was significantly higher in the non-OSA group ( P < .05) and mild OSA group ( P < .01) than in the severe OSA group. As the severity of OSA increased, the interleukin-5 level significantly increased, which caused a difference between mild OSA and moderate OSA ( P < .05) and between mild OSA and severe OSA ( P < .001). In the univariate quantile regression analysis of IGF-1, there was a negative relationship between IGF-1 and IL-5 ( P < .001). IGF-1 was positively correlated with age, height, and minimum oxygen saturation. Furthermore, there was a negative correlation between the IGF-1 level and the severity of OSA. Quantile regression analysis on the multivariable analysis of the IGF-1 association showed that height, sex, and severity of OSA played important roles in affecting IGF-1 levels. Conclusion: High IL-5 levels may lead to the low secretion of growth hormone level (IGF-1) in children, thus affecting growth and development.

Association between obstructive sleep apnea and 24-h urine protein quantification in patients with hypertension

The association between obstructive sleep apnea (OSA) and proteinuria is undetermined, with few studies on hypertension, a high-risk group for renal impairment. Therefore, we aimed to explore whether OSA is an independent risk factor for proteinuria in patients with hypertension. We investigated the cross-sectional association between OSA and proteinuria. Participants were divided into groups by apnea hypopnea index (AHI) category. Multivariable Logistic regression analysis was used to evaluate the association between OSA severity, objectively measured sleep dimensions, and proteinuria which is mainly defined by 24-h urine protein quantification > 300 mg/24 h. Sensitivity analyses were performed by excluding those with comorbidities (primary aldosteronism and homocysteine ≥ 15 μmol/L). Of the 2106 participants, the mean age was 47.57 ± 10.50 years, 67.2% were men, and 75.9% were OSA patients. In total participants, compared with those without OSA, patients with mild OSA, moderate OSA, and severe OSA showed 1.09 (95% CI 0.80–1.40), 1.24 (95% CI 0.89–1.74) and 1.47 (95% CI 1.04–2.08) fold risk for proteinuria with a trend test P trend < 0.05. Each 10-unit increase in the AHI, oxygen desaturation index (ODI), and time spent with oxygen saturation < 90% (T90) was found to be associated with 13%, 10%, and 2% higher likelihood of proteinuria in the crude model, significant in adjusted models. The more severe the OSA is, the higher the risk of proteinuria. AHI and T90 are independently associated with a higher risk of structural renal damage in the population with hypertension.

Physiological Effects and Tolerance of Wearing Surgical and N95 Masks during Sleep in Normal Individuals and Patients with Mild-Moderate Obstructive Sleep Apnea: A Randomized Crossover Trial

BackgroundIn certain situations, masks are worn during sleep to prevent respiratory infections. However, the effects of mask wearing on cardiopulmonary function during sleep are unknown. This study aimed to determine whether wearing masks during sleep has an impact on cardiopulmonary function, including in patients with obstructive sleep apnea. MethodsThis was a prospective, randomized crossover-controlled trial. The effects of wearing surgical masks or N95 respirators on cardiopulmonary function were measured in healthy subjects and patients with mild-moderate obstructive sleep apnea. Sleep breathing parameters were monitored during nocturnal sleep using a sleep monitor, and subjective feelings about mask wearing were assessed using a questionnaire. ResultsWearing masks during sleep at night did not significantly impact sleep breathing parameters. Furthermore, there were no significant differences in heart rate, blood oxygenation, and blood pressure before and after wearing masks. However, wearing masks, especially the N95 mask, had an adverse impact on sleep quality, and masks were found to be subjectively uncomfortable. ConclusionWearing masks during sleep at night does not adversely affect cardiopulmonary function but they can be uncomfortable, especially the N95 mask. Thus, in circumstances where wearing N95 masks during nocturnal sleep proves intolerable, we recommend the use of surgical masks as a more comfortable alternative.

Combination of acute intermittent hypoxia and intermittent transcutaneous electrical stimulation in obstructive sleep apnea: a randomized controlled crossover trial

Intermittent hypoxia (IH) and intermittent transcutaneous electrical stimulation (ITES) might benefit patients with obstructive sleep apnea (OSA). However, the therapeutic value of combined IH and ITES in OSA is unknown. In this prospective, randomized, controlled crossover study, normoxia (air exposure for 50 min before sleep and sham stimulation for 6 h during sleep), IH (5 repeats of 5 min 10–12 % O2 alternating with 5 min air for 50 min, and sham stimulation for 6 h), ITES (air exposure for 50 min and 6 repeats of 30 min transcutaneous electrical stimulation alternating with 30 min of sham stimulation for 6 h), and IH&ITES (10–12 % O2 alternating with air for 50 min and transcutaneous electrical stimulation alternating with sham stimulation for 6 h) were administered to patients with OSA over four single-night sessions. The primary endpoint was difference in OSA severity between the interventions according to apnea-hypopnea index (AHI) and oxygen desaturation index (ODI). The efficacy was response to IH, ITES, IH&ITES defined as a ≥50 % reduction in AHI compared with normoxia. Twenty participants (17 male, 3 female) completed the trial. The median (IQR) AHI decreased from 14.5 (10.8, 17.5) events/h with normoxia to 6.9 (3.9, 14.8) events/h with IH (p=0.020), 5.7 (3.4, 9.1) events/h with ITES (p=0.001), and 3.5 (1.8, 6.4) events/h with IH&ITES (p=0.001). AHI was significantly different between IH and IH&ITES (p=0.042) but not between ITES and IH&ITES (p=0.850). For mild-moderate OSA (n=17), IH, ITES, and IH&ITES had a significant effect on AHI (p=0.013, p=0.001, p=0.001, respectively) compared with normoxia, but there were no differences in post hoc pairwise comparisons between intervention groups. No serious adverse events were observed. In conclusion, IH, ITES, and IH&ITES significantly reduced OSA severity. IH&ITES showed better efficacy in mild-moderate OSA than IH and was comparable to ITES. Our data do not support recommending IH&ITES over ITES for OSA.

Subjective cognitive complaints and objective cognitive impairment in patients suspected of obstructive sleep apnea who underwent polysomnography.

Obstructive sleep apnea (OSA) is linked to cognitive impairment. We aimed to investigate subjective cognitive complaints (SCCs) and objective cognitive scores and their relation to polysomnography (PSG) parameters in patients suspected of having OSA. A prospective cohort cross-sectional study was conducted at Siriraj Hospital. Patients suspected of OSA who were scheduled for PSG were recruited. Cognition was assessed using the Montreal Cognitive Assessment (MoCA) and Color Trails Test (CTT). The Memory Index Score (MIS) was calculated from the MoCA. Subjective cognitive complaint presence was assessed through direct questioning of patients and by employing the Cognitive Change Index rated by self or informants (CCI-I). Patients with severe dementia were excluded. Among 258 patients (mean age 61.46±7.05years, 51.2% female), the mean MoCA score was 23.89±3.89. Based on PSG results, patients were categorized into groups as follows: those without OSA or with mild OSA (combined total of 20.1%), moderate OSA (28.3%), or severe OSA (51.6%). Cognitive Change Index rated by self and CCI-I scores correlated significantly (r=0.238, p=0.019) but not with the MoCA score or CTT time. Objective cognitive scores were associated with PSG parameters: total sleep time (TST), sleep onset latency, wake after sleep onset, sleep stages, mean O2 saturation, and time spent with SaO2 below 90% (all p<0.05). Subjective cognitive scores were not associated with PSG parameters, except CCI-I with TST. Participants with objective cognitive impairment had lower education, higher body mass index, more comorbidities, and lower SCC percentage (all p<0.05). Patients with moderate to severe OSA had a higher proportion of objective cognitive impairment (64.1%) but a lower incidence of SCC (38.3%) than patients with no OSA or mild OSA. Thirty patients with severe OSA and cognitive impairment received continuous positive airway pressure (CPAP) treatment for a mean of 12.2months. These patients showed MoCA and MIS improvement, but no significant changes were observed in their CTT and Cognitive Change Index scores. Most patients with OSA had objective cognitive impairment, but SCC was less frequent in patients with more severe OSA. Several PSG parameters correlated with cognitive scores but not with subjective cognitive scores. Patients with severe OSA may benefit cognitively from CPAP treatment.

Effect of Prosthetic Rehabilitation on Airway Space in Edentulous Patients with Obstructive Sleep Apnea- a Preliminary Observational Study.

The common causes of obstructive sleep apnea (OSA) are identified as anatomic and/or functional abnormality in the oral cavity, oropharynx, velopharynx, and hypopharynx leading to compromised airway space and increased collapsibility. This study was conducted to evaluate the effect of implant-supported mandibular complete denture in improving the airway space among completely edentulous patients with OSA and compare it with conventional complete denture. In this observational study, completely edentulous individuals were screened with snoring, tiredness, observed apnea, high blood pressure, body mass index, age, neck circumference, and gender (STOP-Bang) questionnaire to evaluate the incidence of OSA. Ten mild-moderate patients were included as study participants. Lateral cephalograms (L1) made at the edentulous state was considered baseline. They were rehabilitated with complete denture prosthesis. One week after denture insertion, two implants were placed in the edentulous mandibular arch. Delayed loading protocol was followed. Lateral cephalogram (L2) was made 6 months after complete denture insertion and 6 months after implant-supported prosthesis (L3). Cephalometric tracings were used to evaluate change in upper airway space (UAS), middle airway space (MAS), and lower airway space (LAS). Repeated measures ANOVA was used to evaluate statistical significance in the airway measurements made at the three intervals. Post hoc Tukey HSD and Bonferroni test were used to assess if the differences obtained were truly significant. Statistical analysis revealed significant differences in UAS, MAS and LAS between L1, L2 and L3 (p< 0.05). Post hoc Tukey HSD indicated that UAS increased significantly at all three intervals followed by LAS and MAS respectively (α=.05). Post hoc Bon-ferroni test indicated that implant-supported mandibular complete dentures had a significant improvement in airway space when compared to conventional complete dentures (α=.05). Implant-supported mandibular complete denture could be effective in edentulous patients with mild-moderate OSA.

Characteristics of genioglossus neuromuscular activity in patients with obstructive sleep apnea during drug-induced sleep

Objective: To analyze genioglossus (GG) activation responses to the negative pressure of upper airway cavity during awake and different sleep stages in patients with different obstructive sleep apnea (OSA) graduation. Methods: This prospective cohort study started from August 2019 to January 2021, recruited 42 male OSA patients aged from 21 to 59 (38.77±8.42) years. After completing whole night polysomnography (PSG) and upper airway CT, each subject underwent drug-induced sleep with simultaneous monitoring of genioglossal electromyography (GGEMG) and pressure of epiglottis (Pepi). Subjects were divided into three groups of mild OSA(7 males), moderate OSA(12 males), and severe OSA(23 males). The differences in upper airway CT measurements, parameters of GGEMG and Pepi during awake and induced sleep were compared. Statistical analysis was conducted by SPSS 21.0. Results: There was no significant difference in the GGEMG parameters between the mild and moderate groups. In wakefulness, the peak phasic GGEMG of the severe group was higher than the mild group (t=1.249, P=0.025), with no statistically difference in the corresponding Pepi. In the sleep onset, the GGEMG parameters and Pepi in severe group were higher than the other two groups. Linear regression analysis of the maximum GGEMG and maximum Pepi at the end of obstructive apnea (OA) in all moderate plus severe patients (n=35) was shown nonlinear correlation (r=0.28, P=0.694). The airway length of the glossopharyngeal cavity was linearly correlated with the maximum Pepi of OA (r=0.468, R2=0.219, P=0.005). Conclusions: The individual difference of GG activation in OSA patients is related to the severity of the disease (frequency of respiratory events) and negative pressure stimulation. In moderate and severe OSA patients, GG activity is not in harmony with the corresponding negative pressure stimulation, which may be one of the mechanisms leading to the aggravation of OSA.

A randomized controlled crossover trial of acute intermittent and continuous hypoxia exposure in mild-moderate obstructive sleep apnea: A feasibility study.

In a prospective, randomized, controlled crossover study, we explored the effects of acute intermittent hypoxia and acute continuous hypoxia on patients with mild-moderate obstructive sleep apnea. Over three single-night sessions, subjects were alternately exposed to normoxia, acute continuous hypoxia and acute intermittent hypoxia before sleep. The apnea-hypopnea index and oxygen desaturation index were used to diagnose obstructive sleep apnea and evaluate efficacy. A responder was defined as a participant with a ≥ 50% reduction in apnea-hypopnea index between normoxia and hypoxia exposure. Sixteen participants with mild-moderate obstructive sleep apnea completed the study. Compared with normoxia, the mean apnea-hypopnea index decreased by 8.9 events per hr (95% confidence interval, 4.2-13.6, p = 0.001) with acute intermittent hypoxia and by 4.1 events per hr (95% confidence interval, 0.5-8.8, p = 0.082) with acute continuous hypoxia, equating to a mean decrease in apnea-hypopnea index of 4.8 events per hr (95% confidence interval, 0.1-9.5, p = 0.046) with acute intermittent hypoxia compared with acute continuous hypoxia. Compared with normoxia, the mean oxygen desaturation index decreased by 9.8 events per hr (95% confidence interval, 4.4-15.1, p = 0.001) with acute intermittent hypoxia but did not significantly decrease with acute continuous hypoxia; the mean oxygen desaturation index decreased by 7.2 events per hr (95% confidence interval, 1.8-12.6, p = 0.010) with acute intermittent hypoxia compared with acute continuous hypoxia. Of the 16 participants, 11 responded to acute intermittent hypoxia and four responded to acute continuous hypoxia (p = 0.032), of whom eight of 11 cases and all four cases had oxygen desaturation indexes <5 events per hr, respectively (p = 0.273). All participants tolerated acute intermittent hypoxia and there were no obvious adverse events during acute intermittent hypoxia exposure. In conclusion, acute intermittent hypoxia exposure improved apnea-hypopnea index and oxygen desaturation index in patients with mild-moderate obstructive sleep apnea, suggesting that further prospective validation of intermittent hypoxia exposure in patients with obstructive sleep apnea is needed to establish its clinical feasibility as a therapeutic modality.

Anatomical phenotype of obstructive sleep apnea patients based on cluster analysis.

To generate a novel subtype of obstructive sleep apnea (OSA) based on anatomical features and verify the differences in the response of different subtypes to orthodontic treatment, thus providing a theoretical reference for clinical decision-making. A K-means cluster analysis was performed for this retrospective serial study, which includes 722 OSA patients, aged 44.0 (36.0, 54.0) years, 80.2% male, with apnea-hypopnea index (AHI) of 23.2 (13.4, 39.6) events·h-1 , and body mass index (BMI) of 25.47 ± 3.00 kg·m-2 . All samples were divided into three subtypes based on AHI, BMI, and five variables of craniofacial measurements. Sixty-seven cases with mandibular advancement devices (MAD) therapeutic results were further applied to validate the efficacy and side effects of this treatment in different subtypes. Two hundred and thirty patients (31.9%) were characterized as cluster 1: AHI of 17.65 (11.80, 30.42) events·h-1 , BMI of 23.65 ± 2.62 kg·m-2 , with skeletal Class II high-angle shape. Cluster 2 included 278 patients (38.5%): AHI of 17.00 (11.00, 26.48) events·h-1 , BMI of 25.36 ± 2.53 kg·m-2 , soft palate length (SPL) of 39.25 mm (36.12, 42.20), with basically normal skeleton and normal airway size. Cluster 3, consisting of 214 patients (29.6%), exhibited a combination of anatomical deformity and obesity, with the highest AHI and BMI of 45.35 (30.42, 62.53) events·h-1 and 27.57 ± 2.59 kg·m-2 respectively, but less deformity degree than cluster 1. Cluster 2 had the highest response rate and relatively mild side effects with MAD. Orthodontic treatment based on anatomical morphology could exert a better effect on mild-moderate OSA patients with mild skeletal deformity.

Association between obstructive sleep apnea and thyroid function: A 10-year retrospective study

PurposeTo explore whether the obstructive sleep apnea (OSA) has an impact on thyroid function in patients. MethodThe data of 853 patients were retrospectively collected from the Second Affiliated Hospital of Xi'an Jiaotong University in recent ten years. All the objects were divided into the control group, mild-moderate and severe OSA groups according to the result of polysomnography. ResultsIn the non-elderly population (age <60), there were significant differences in serum free triiodothyronine (FT3) and total triiodothyronine (TT3) between the mild-moderate and severe OSA groups (all p < 0.05). And there were differences in serum total thyroxine, anti–thyroid peroxidase, and antithyroglobulin between the control and mild-moderate OSA groups (all p < 0.05). Moreover, FT3 was associated with age (OR = 0.98, p < 0.05) and apnea–hypopnea index (OR = 1.01, p < 0.05). The occurrence of thyroid nodules was associated with average transcutaneous oxygen saturation (Mean SaO2) (OR = 0.97, p < 0.05). In the elderly (age ≥60), there was no difference in FT3 and TT3 between the mild-moderate and severe OSA. While the occurrence of thyroid nodules was also associated with Mean SaO2 (OR = 0.90, p < 0.05). ConclusionIn the non-elderly population, the progress of OSA may promote the increase in thyroid hormone (especially FT3) levels, while in the elderly population not. In the whole age population, Mean SaO 2 is associated with the occurrence of thyroid nodules. Future research on the relationship between OSA and thyroid function, and age stratification is necessary.

Association Between Metabolic-Associated Fatty Liver Disease and Obstructive Sleep Apnea: A Cross-Sectional Study.

Emerging evidence has revealed that obstructive sleep apnea (OSA) is an independent risk factor for the development of a variety of adverse metabolic disease states. In this study, we evaluated the association between OSA severity and metabolic dysfunction-associated fatty liver disease (MAFLD) among Asian populations. This was a cross-sectional, single-center study. The study cohort consisted of patients undergoing polysomnography and abdominal ultrasonography. Logistic regression analysis was used to evaluate the independent risk factors of MAFLD in patients with OSA. A total of 1065 patients (277 non-MAFLD and 788 MAFLD) were included in the study. The prevalence of MAFLD in non-OSA, mild-moderate OSA, and severe OSA patients was 58.16%, 72.41%, and 78.0%, respectively (p < 0.001). We identified significant differences in body mass index (BMI), apnea-hypopnea index (AHI), oxygen desaturation index (ODI), and lowest O2 saturation (LaSO2) between non-MAFLD and MAFLD patients (all p < 0.001). After adjusting for confounding variables, we used multivariate regression analysis to show that BMI, ODI, and triglyceride (TG) levels independently predicted the occurrence of MAFLD (odds ratio [OR] = 1.234, p < 0.001; OR = 1.022, p = 0.013; OR = 1.384, p = 0.001, respectively). Moreover, stratified analysis according to BMI indicated that TG levels were the predominant risk factor for MAFLD in a group of patients with a BMI < 23 kg/m2, while BMI, ODI, TG levels, and total cholesterol (TC) were the major risk factors for MAFLD in a group of patients with a BMI ≥ 23 kg/m2 (all p < 0.05). OSA-associated chronic intermittent hypoxia was independently associated with the risk of MAFLD, especially in OSA patients with a BMI ≥ 23 kg/m2, suggesting that oxidative stress might play an important role in the pathogenesis of MAFLD in patients with OSA.

PS-C29-5: PULMONARY HYPERTENSION AND RIGHT VENTRICULAR REMODELING IN OBSTRUCTIVE SLEEP APNEA

Background and Objective: Acute pulmonary artery (PA) pressure changes during sleep have been extensively reported in obstructive sleep apnea (OSA). However, the role of OSA as an independent risk factor for the day-time pulmonary hypertension (PH) is not well known. The present study was conducted to examine whether OSA is associated with PH and right ventricular (RV) remodeling. Methods: 423 OSA patients without chronic obstructive pulmonary disease or left ventricular dysfunction {age: 55 ± 13 years old, mean apnea-hypopnea index (AHI): 41 ± 22 /h} were enrolled in this study. All patients were performed polysomnography, echocardiography and spirometry. Pulmonary artery systolic pressure (PASP) was determined by continuous-wave Doppler using the simplified Bernoulli equation. For this study, PH was defined as an estimated PASP of greater than 30 mmHg. Patients were divided into two groups: mild-moderate OSA group (n = 153) (AHI = 5–30 /h) and severe OSA group (n = 270)(AHI over 30/h). Results: The prevalence of PH among all OSA patients was 19%. No significant differences were found in PASP, tricuspid annular velocity and tricuspid annular plane systolic excursion (TAPSE) between mild-moderate OSA group and severe OSA group. However, RV diastolic diameter (28.7 ± 3.4 vs 27.7 ± 3.0 mm, respectively, P &lt; 0.01) and main PA diameter (26.2 ± 3.7 vs 24.8 ± 3.9 mm, respectively, P &lt; 0.05) were significantly higher in severe OSA group than those in mild-moderate OSA group. Conclusions: The severity of OSA was significantly associated with RV and PA diameters independently PASP. These results suggested that OSA may directly affects RV and PA remodeling independently PH.

Characteristics of patients with positional OSA according to ethnicity and the identification of a novel phenotype-lateral positional patients: a Multi-Ethnic Study of Atherosclerosis (MESA) study.

We investigated the characteristics of obstructive sleep apnea (OSA) positional patients' (PP) phenotypes among different ethnic groups in the Multi-Ethnic Study of Atherosclerosis (MESA) dataset. Moreover, we hypothesized the existence of a new OSA PP phenotype we coined "Lateral PP," for whom the lateral apnea-hypopnea index is at least double the supine apnea-hypopnea index. From 2,273 adults with sleep information, we analyzed data of 1,323 participants who slept more than 4 hours and had at least 30 minutes of sleep in both the supine and the nonsupine positions. Demographics and clinical information were compared for the different PP and ethnic groups. 861 (65.1%) patients had OSA, and 35 (4.1%) were Lateral PP. Lateral PP patients were mainly females (62.9%), obese (median body mass index: 31.4 kg/m2), had mild-moderate OSA (94.3%), and mostly were non-Chinese American (97.1%). Among all patients with OSA, 550 (63.9%) were Supine PP and 17.7% were supine-isolated OSA. Supine PP and Lateral PP were present in 73.1% and 1.0% of Chinese Americans, 61.0% and 3.4% of Hispanics, 68.3% and 4.7% of White/Caucasian, and 56.2% and 5.2% of Black/African-American patients with OSA. Chinese Americans have the highest prevalence of Supine PP, whereas Black/African-American patients lean toward less Supine PP and higher Lateral PP. Lateral PP appears to be a novel OSA phenotype. However, Lateral PP was observed in a small group of patients with OSA and thus its existence should be further validated. Ben Sason Y, Oksenberg A, Sobel JA, Behar JA. Characteristics of patients with positional OSA according to ethnicity and the identification of a novel phenotype-lateral positional patients: a Multi-Ethnic Study of Atherosclerosis (MESA) study. J Clin Sleep Med. 2023;19(3):529-538.

Study on Relationship Between Carotid Intima-Media Thickness and Inflammatory Factors in Obstructive Sleep Apnea.

The purpose of this study was to explore the change of carotid intima-media thickness (IMT) and its correlation with inflammatory markers in patients with different degrees of obstructive sleep apnea (OSA). One hundred hospitalized patients were selected and were divided into the normal control group (21 cases), the mild-moderate group (39 cases) and the severe group (40 cases) according to their apnea hypopnea index (AHI). Carotid IMT of all registered patients was studied with ultrasound, and serum levels of high-sensitivity C-reactive protein (hs-CRP), Lipoprotein-associated phospholipaseA2 (Lp-PLA2) and tumor necrosis factor-α (TNF-α) were measured. Pearson correlation analysis and multiple stepwise regression analysis were used to analyze the correlation between carotid IMT and inflammatory factors. Patients with mild, moderate and severe OSA Carotid IMT had significantly higher levels of serum hs-CRP, Lp-PLA2 and TNF-α compared with the normal control group (P < 0.001). The levels of carotid IMT, serum protein hs-CRP, Lp-PLA2 and TNF-α in the severe OSA group were significantly higher than those of the mild-moderate OSA group, with P values being less than 0.001. Carotid artery IMT was positively correlated with serum hs-CRP (r = 0.83, P < 0.001), Lp-PLA2 (r =0.58, P < 0.001), and TNF-α (r =0.69, P < 0.001). hs-CRP, TNF-α and AHI were independent factors affecting carotid artery IMT. In addition, AHI was an independent indicator of carotid atherosclerosis (P = 0.0012). Increased inflammatory factors in OSA patients might cause the progression of atherosclerosis, which might increase the risk of cardiovascular and cerebrovascular diseases in OSA patients.

Information-Based Similarity of Ordinal Pattern Sequences as a Novel Descriptor in Obstructive Sleep Apnea Screening Based on Wearable Photoplethysmography Bracelets.

Obstructive sleep apnea (OSA) is a common respiratory disorder associated with autonomic nervous system (ANS) dysfunction, resulting in abnormal heart rate variability (HRV). Capable of acquiring heart rate (HR) information with more convenience, wearable photoplethysmography (PPG) bracelets are proven to be a potential surrogate for electrocardiogram (ECG)-based devices. Meanwhile, bracelet-type PPG has been heavily marketed and widely accepted. This study aims to investigate the algorithm that can identify OSA with wearable devices. The information-based similarity of ordinal pattern sequences (OP_IBS), which is a modified version of the information-based similarity (IBS), has been proposed as a novel index to detect OSA based on wearable PPG signals. A total of 92 PPG recordings (29 normal subjects, 39 mild-moderate OSA subjects and 24 severe OSA subjects) were included in this study. OP_IBS along with classical indices were calculated. For severe OSA detection, the accuracy of OP_IBS was 85.9%, much higher than that of the low-frequency power to high-frequency power ratio (70.7%). The combination of OP_IBS, IBS, CV and LF/HF can achieve 91.3% accuracy, 91.0% sensitivity and 91.5% specificity. The performance of OP_IBS is significantly improved compared with our previous study based on the same database with the IBS method. In the Physionet database, OP_IBS also performed exceptionally well with an accuracy of 91.7%. This research shows that the OP_IBS method can access the HR dynamics of OSA subjects and help diagnose OSA in clinical environments.

Associations between abdominal obesity and the risk of stroke in Chinese older patients with obstructive sleep apnea: Is there an obesity paradox?

Background and purposeAbdominal obesity (AO) is a well-known independent risk factor for stroke in the general population although it remains unclear in the case of the elderly, especially in Chinese older patients with obstructive sleep apnea (OSA), considering the obesity paradox. This study aimed to investigate the association between AO and stroke among Chinese older patients with OSA.MethodsData were collected from January 2015 to October 2017, and 1,290 older patients (age 60–96 years) with OSA (apnea–hypopnea index ≥ 5 events/h on polysomnography) were consecutively enrolled from sleep centers at six hospitals, evaluated for AO defined as waist circumference (WC) using the standardized criteria for the Chinese population, and followed up prospectively for a median period of 42 months. Logistic regression and Cox regression analyses were used to determine the cross-sectional and longitudinal associations between AO and stroke risk in these participants and different groups of the severity of OSA.ResultsParticipants with AO had a higher prevalence of stroke at baseline. A higher incidence of stroke during a median follow-up period of 42 months in participants with AO than in participants without AO (12.4% vs. 6.8% and 8.3% vs. 2.4%, respectively; both P < 0.05) was predicted. Cross-sectional analysis revealed an association between AO and stroke (odds ratio [OR]1.96, 95% confidence interval [CI] 1.31–2.91), which was stronger among participants with moderate OSA only (OR 2.16, 95%CI 1.05–4.43). Cox regression analysis showed that, compared to participants without AO, participants with AO had a higher cumulative incidence of stroke (hazard ratio [HR] 2.16, 95% CI 1.12–4.04) during a median follow-up of 42 months, and this association was observed in patients with severe OSA only (HR 3.67, 95% CI 1.41–9.87) but not for individuals with mild OSA (HR = 1.84, 95% CI 0.43–6.23) and moderate OSA (HR = 1.98, 95% CI 0.73–6.45).ConclusionThe risk of stroke is associated with AO among Chinese older patients who have OSA, both at baseline and during follow-up, and the strength of the association varied by OSA severity. Active surveillance for early detection of AO could facilitate the implementation of stroke-preventive interventions in the Chinese older OSA population.

Management of pharyngeal collapse in patients affected by moderate obstructive sleep apnoea syndrome.

SUMMARYObjectiveThis study reports our experience in a selected cohort of patients affected by mild-moderate OSAS, without tonsillar obstruction, and treated with pharyngoplasty.MethodsIn a case-control retrospective study, we compared modified expansion sphincter pharyngoplasty (MESP) to modified barbed reposition pharyngoplasty (MBRP) in adult patients with oropharyngeal transversal collapse with a BMI ≤ 30 kg/m2, and mild-moderate obstructive sleep apnoea syndrome (OSAS). A clinical evaluation, including collection of anthropometric data and sleep endoscopy, was performed. Six months after surgery, symptoms recording, clinical evaluation and polysomnography (PSG) were repeated.ResultsWe enrolled 20 patients: 10 treated with MESP and 10 treated with MBRP. Mean apnoea-hypoapnoea index (AHI) was 22.8 (± 5.63). We observed in both groups a significant reduction of AHI and oropharyngeal obstruction (p = 0.01), with a success rate, according with Sher’s criteria, of 90% for MESP and 80% for MBRP, respectively. Post-surgical pain and snoring reduction were significantly lower with MBRP.ConclusionsWe recorded similar success rates for both techniques. MBRP may be considered better than MESP due to less surgical time, no potential mucosal damage, absence of knots, and faster recovery with less pain.

Coronary computed tomography angiography-based assessment of vascular inflammation in patients with obstructive sleep apnoea and coronary artery disease.

Obstructive sleep apnoea (OSA) is associated with increased coronary artery disease (CAD) plaque burden, but the role of vascular inflammation in this relationship is unclear. Coronary computed tomography angiography (CTA) enables surrogate assessment of systemic inflammation via subcutaneous adipose tissue attenuation (SCAT-a), and of coronary inflammation via epicardial adipose tissue volume and attenuation (EAT-v and EAT-a) and pericoronary adipose tissue attenuation (PCAT-a). We investigated whether patients with severe OSA and high plaque burden have increased vascular inflammation. Patients with overnight polysomnography within ≤12 months of coronary CTA were included. Severe OSA was classified as apnoea/hypopnoea index (AHI) >30. High plaque burden was defined as a CT-adapted Leaman score (CT-LeSc) ≥8.3. Patients with both severe OSA and high plaque burden were defined as 'Group 1', all other patients were classified as 'Group 2'. ScAT, PCAT and EAT attenuation and volume were assessed on semi-automated software. A total of 91 patients were studied (59.3±11.1 years). Severe OSA was associated with high plaque burden (P=0.02). AHI correlated with CT-LeSc (r=0.24, P=0.023). Group 1 had lower EAT-a and PCAT-a compared to Group 2 (EAT-a: -87.6 vs. -84.0 HU, P=0.011; PCAT-a: -90.4 vs. -83.4 HU, P<0.01). However, among patients with low plaque burden, EAT-a was higher in the presence of severe OSA versus mild-moderate OSA (-80.3 vs. -84.0 HU, P=0.020). On multivariable analysis, severe OSA and high plaque burden associated with EAT-a (P<0.02), and severe OSA and high plaque burden (P<0.01) and hypertension (P<0.01) associated with PCAT-a. EAT and PCAT attenuation are decreased in patients with severe OSA and high plaque burden, but EAT attenuation was increased in patients with severe OSA and low plaque burden. These divergent results suggest vascular inflammation may be increased in OSA independent of CAD, but larger studies are required to validate these findings.