Obstructive Sleep Apnea Subgroup Research Articles

PLASMA ADIPONECTIN LEVELS IN OBSTRUCTIVE SLEEP APNEA: A CROSS SECTION STUDY

Background: Obstructive sleep apnea (OSA) is a disorder of airway obstruction during sleep with multisystem implications and associated complications, while mostly underdiagnosed and undertreated. It has drawn more attention in recent years with a substantial increase in its prevalence. Studies reported inconclusive results for the association of adiponectin with OSA as a reliable biomarker. The present study aimed to evaluate this association. Methods: A total of 88 participants, including 44 apnea subjects and 44 controls, fulfilling the inclusion and exclusion criteria, were selected for this cross-sectional study ?performed from Dec 2018 to Jan 2020. Apnea subjects were selected after confirmation of their OSA by overnight polysomnography, and classified into mild, moderate, and severe OSA groups based on their Apnea-Hypopnea Index (AHI). Blood samples were collected in EDTA-containing tubes and Enzyme-link immune-sorbent assay (ELISA) was done for plasma levels of adiponectin. SPSS-20 was used for analysis of the data. Results: Mean adiponectin level was significantly higher in controls as it was 9.16±3.54 µg/ml for controls and 3.47±2.03 µg/ml for OSA. Comparison between different OSA sub-group revealed mean adiponectin as 3.99±1.69, 2.73±1.65, and 3.64±2.30 µg/ml in mild, moderate, and severe OSA groups respectively. Conclusion: Lower plasma adiponectin levels ?were identified among OSA subjects as compared to controls. Lower levels of adiponectin are associated with the presence of OSA and could be helpful to identify subjects who are at risk for OSA-related comorbidities. Pak J Physiol 2023;19(1):17–20

Associations Between Systemic Inflammatory Markers Based on Blood Cells and Polysomnographic Factors in Obstructive Sleep Apnea.

Systemic inflammation plays a key role in the pathogenesis of obstructive sleep apnea (OSA); however, easy-to-use methods to evaluate the severity of systemic inflammation have yet to be developed. This study investigated the association between systemic inflammation markers that could be derived from the complete blood count (CBC) profile and sleep parameters in a large number of patients with OSA. Patients who visited our hospital's Otorhinolaryngology Sleep Clinic between January 2017 and April 2022 underwent polysomnography and routine laboratory tests, including a CBC. Associations between three systemic inflammatory markers-the systemic immune-inflammation index (SII), neutrophil-lymphocyte ratio (NLR), and platelet-lymphocyte ratio (PLR)-and polysomnographic and demographic factors including age, sex, body mass index, the apnea-hypopnea index (AHI), the hypopnea index (HI), lowest oxygen saturation (%), the Pittsburgh Sleep Quality Index (PSQI), the Epworth Sleepiness Scale, and percentages of non-rapid eye movement (REM) sleep stage 3, REM sleep, and snoring time were analyzed. The inflammation markers were compared among OSA subgroups, and associations were also analyzed in subgroups with different OSA severities. In total, 1,102 patients (968 men and 134 women) were included, and their mean AHI was 33.0±24.3. PSQI was significantly associated with SII (P=0.027). No independent significant factors were identified for the NLR or PLR. Within the simple snoring and mild OSA subgroups, no significant association was found between sleep parameters and the SII. In the severe OSA subgroup, the AHI (P=0.004) and PSQI (P=0.012) were independently associated with the SII. Our study analyzed systemic inflammatory markers based on the CBC, a simple, relatively cost-effective test, and showed that the AHI and SII were significantly correlated only in the severe OSA subgroup.

The Associations between Polysomnographic Parameters and Memory Impairment among Patients with Obstructive Sleep Apnea: A 10-Year Hospital-Based Longitudinal Study

Obstructive sleep apnea (OSA) has been associated with cognitive decline via several mechanisms, including intermittent hypoxemia, sleep fragmentation, and neuroinflammation. The neurological consequences of OSA have evolved into a major biopsychosocial concern in the elderly, especially memory impairment. We aimed to identify the polysomnographic (PSG) parameters capable of predicting memory impairment among OSA patients at or over age 50 with OSA. We reviewed the 10-year electronic medical records of OSA patients and compared the initial PSG parameters between those presenting and not presenting self-reported memory impairment. We conducted subgroup analyses based on OSA severity and performed multivariate analysis to correlate PSG parameters with memory impairment. The result showed that 25 out of the 156 (16%) investigated patients experienced self-reported memory impairment during follow-up. As compared to OSA patients without self-reported memory impairment, those reported with self-reported memory impairment had a higher oxygen desaturation index (ODI) (23.9 ± 17.8 versus 18.2 ± 12.0, p = 0.048). Regarding the associations between apnea-hypopnea index (AHI) as well as ODI and self-reported memory impairment among OSA subgroups classified by severity, the associations were only evident in the severe OSA subgroup in both univariate (p < 0.001; p = 0.005) and multivariate analyses (p = 0.014; p = 0.018). We concluded that AHI and ODI are the most relevant PSG parameters in predicting memory impairment in severe OSA patients.

S239 The Association of Obstructive Sleep Apnea and Clostridium difficile: A Nationwide Inpatient Sample Analysis

Introduction: Obstructive sleep apnea (OSA) is a sleep disorder involving repeated apneic episodes during sleep due to an obstruction of the airflow. OSA predisposes individuals to community-acquired pneumonia due to upper airway microaspiration. Furthermore, hypoxia due to intermittent pharyngeal collapses is shown to cause a pro-inflammatory state and reduced NK cell cytotoxicity and maturation, which can increase the risks of infections due to suppression of immune response. Increased incidence of infections in the OSA subgroup leads to increased use of antibiotics. Antibiotic exposure is the primary risk factor for developing Clostridium difficile (C. diff) infection. In synchrony with this notion, the primary purpose of this study was to determine the association between OSA and C. diff infection. Methods: A retrospective analysis was conducted using the Healthcare Cost and Utilization Project-Nationwide Inpatient Sample (HCUP-NIS). Patients without C. diff were analyzed (control) and were randomly selected and matched to each patient who did have C. diff. Weighted logistic regression models were used to calculate the association between OSA and C. diff for different comorbidities. Results: A total of 7,135,090 patients were included in our analysis. The prevalence of C. diff was significantly higher in patients with OSA (1.19% vs. 1.00%, p< 0.0001). In addition, multiple comorbidities were significantly elevated in the OSA group compared to those without OSA, including alcohol and obesity (p< 0.0001). Conclusion: This study uses ICD-10-CM codes with a specific search code for OSA. Our large population database shows a significant association between OSA and C. diff. One of the hypotheses describing this increased association could be more antibiotic exposure in OSA subgroup leading to C. diff. Additional studies are needed to confirm or refute this association.

Development and Validation of a Prognostic Nomogram in Lung Cancer With Obstructive Sleep Apnea Syndrome.

To analyze the prognostic factors and survival rate of lung cancer patients with obstructive sleep apnea (OSA) by nomogram. The nomogram was established by a development cohort (n = 90), and the validation cohort included 38 patients. Factors in the nomogram were identified by Cox hazard analysis. We tested the accuracy of the nomograms by discrimination and calibration, and plotted decision curves to assess the benefits of nomogram-assisted decisions. There were significant difference in sex, apnea hypopnea index (AHI), Tumor Node Metastasis (TNM), coronary heart disease, lowest arterial oxygen saturation [LSpO2 (%)], oxygen below 90% of the time [T90% (min)], the percentage of the total recorded time spend below 90% oxygen saturation (TS90%) and oxygen desaturation index (ODI4) between lung cancer subgroup and lung cancer with OSA subgroup (P < 0.05). Lung cancer patients with OSA age, AHI, TNM, cancer types, BMI and ODI4 were independent prognostic factor. Based on these six factors, a nomogram model was established. The c-index of internal verification was 0.802 (95% CI 0.767–0.885). The ROC curve analysis for the nomogram show 1-year survival (AUC = 0.827), 3-year survival (AUC = 0.867), 5-year survival (AUC = 0.801) in the development cohort were good accuracy. The calibration curve shows that this prediction model is in good agreement. Decision curve analysis (DCA) suggests that the net benefit of decision-making with this nomogram is higher, especially in the probability interval of <20% threshold. The nomogram can predict the prognosis of patients and guide individualized treatment.

STOP-BANG screener vs objective obstructive sleep apnea testing among younger veterans with PTSD and insomnia: STOP-BANG does not sufficiently detect risk.

Posttraumatic stress disorder (PTSD) and obstructive sleep apnea (OSA) cooccur even in veterans who are younger with lower body mass index. The STOP-BANG screener for OSA relies heavily on high blood pressure, age, and body mass index and may not generalize to veterans with PTSD. The inability to effectively screen veterans for OSA is problematic given negative outcomes of untreated OSA. Our study compared the STOP-BANG to objective OSA diagnostic testing in 48 younger veterans (mean age 43.7 years; 43.8% Caucasian; 20.8% female) seeking treatment for PTSD and insomnia. Apnea-hypopnea events per hour (apnea-hypopnea index), recorded by NOX T3 sleep monitors, were used to diagnose OSA (apnea-hypopnea index ≥ 5 events/h). Logistic regressions examined how STOP-BANG cut-off scores (≥ 3 and ≥ 5) classified OSA status (apnea-hypopnea index ≥ 5 events/h). Follow-up chi-square goodness-of-fit tests examined single-item STOP-BANG performance in the OSA-positive subsample (n = 28). The STOP-BANG (≥ 3) had good sensitivity (92.6%) but poor specificity (47.6%) and negative (0.16) and positive (1.77) likelihood ratios. The STOP-BANG (≥ 5) led to improved specificity (76.19%), but sensitivity (37.04%) and positive (1.56)/negative likelihood ratios (0.83) were poor. Single-item OSA subgroup analyses revealed that body mass index, age, and neck circumference performed poorly, while tiredness and sex performed well. Findings suggest that the STOP-BANG correctly diagnosed OSA in some veterans but missed OSA in large number of younger veterans with PTSD. This suggests objective diagnostic OSA testing is needed in veterans with PTSD. Future research is needed to develop more accurate OSA screening measures in this population. Registry: ClinicalTrials.gov; Name: Integrated CBT-I on PE and PTSD Outcomes (Impact Study); URL: https://www.clinicaltrials.gov/ct2/show/NCT02774642; Identifier: NCT02774642. Lyons R, Barbir LA, Owens R, Colvonen PJ. STOP-BANG screener vs objective obstructive sleep apnea testing among younger veterans with PTSD and insomnia: STOP-BANG does not sufficiently detect risk. J Clin Sleep Med. 2022;18(1):67-73.

Self‐Reported Daytime Sleepiness is Associated with Telomere Shortening

Traditionally regarded as a consequence of sleep-disordered breathing, excessive daytime sleepiness (EDS) is now recognized as an independent risk factor for cardiovascular disease. Evidence also links the shortening of telomeres, responsible for protecting DNA, with increased cardiovascular disease risk. Interestingly, recent data illustrate telomere lengthening in patients with obstructive sleep apnea (OSA); however, whether EDS is associated with telomere length independently of OSA remains unknown. To examine this potential relationship, we studied 169 subjects with polysomnography assessment who answered “yes” or “no” to experiencing EDS; 70 subjects (41%) reported EDS (59M, 44±12yrs, 30.3±5.5kg/m2) whereas 99 did not (59%, 71M, 40±15yrs, 28.6±7.5kg/m2). Telomere length was quantified via qPCR of genomic DNA isolated from peripheral blood samples and did not differ between individuals reporting EDS compared to those who did not (4,856±280 vs. 4,880±340bp, respectively, P=0.31). However, 50% of subjects reporting EDS had moderate-to-severe OSA (apnea-hypopnea index ≥15events/hr) compared to 28% of the non-EDS group (P<0.01). To account for the confounding effects of OSA on telomere length, we conducted a series of subgroup analyses. Subjects without OSA who reported EDS (n=35, 27M, 39±11yrs, 27.4±5.0kg/m2) had shorter telomeres (4,805±165 vs. 4,875±231bp, P=0.05) than those not reporting EDS (n=71, 47M, 35±11yrs, 26.8±5.4kg/m2). Interestingly, within the OSA subgroup, there were no differences in telomere length (4,897±235 vs. 4,858±251bp, P=0.45) between those with (n=35, 32M, 48±11yrs, 33.2±4.5kg/m2) and without EDS (n=28, 24M, 53±16yrs, 33.1±9.7kg/m2). These effects do not appear to be influenced by subject demographics as no differences were found between compared groups (EDS-OSA vs. nEDS-OSA and OSA+EDS vs. OSA-EDS). Collectively, our data suggest individuals reporting EDS may be at greater risk of developing cardiovascular disease due to accelerated telomere shortening. It also appears OSA and EDS exert differential effects on telomere length.

Cardiovascular Outcomes Post Percutaneous Coronary Intervention in Patients with Obstructive Sleep Apnea and Type2 Diabetes Mellitus: A Systematic Review and Meta-Analysis.

IntroductionType 2 diabetes mellitus (T2DM) is a major risk factor for the occurrence of cardiovascular diseases. Similar to T2DM, obstructive sleep apnea (OSA) is also known to be a risk factor for cardiovascular diseases. In this analysis, we aimed to systematically compare the post-interventional cardiovascular outcomes observed in patients with T2DM with versus without OSA.MethodsElectronic databases were searched for relevant publications comparing the cardiovascular outcomes following percutaneous coronary intervention (PCI) in patients with T2DM with OSA. Cardiovascular outcomes were considered as the relevant endpoints. The RevMan software 5.3 was used to carry out the statistical analysis. Odds ratios (OR) with 95% confidence intervals (CI) were used to represent the results following data assessment.ResultsA total of 1168 participants with T2DM were included in this analysis, of whom 614 had co-existing OSA. The time period of patients’ enrollment varied from year 2002 to 2017. Our current analysis showed that major adverse cardiac events (MACEs) (OR 2.28, 95% CI 1.24–4.18; P = 0.008) and all-cause mortality (OR 1.95, 95% CI 1.08–3.54; P = 0.03) were significantly higher in the OSA subgroup. However, major adverse cerebrovascular and cardiovascular (MACCEs) (OR 1.38, 95% CI 0.97–1.98; P = 0.07) and cardiac death (OR 1.79, 95% CI 0.77–4.16; P = 0.18) were not significantly different post PCI. In addition, hospitalization for heart failure (OR 1.99, 95% CI 0.43–9.25; P = 0.38), re-infarction (OR 1.52, 95% CI 0.85–2.70; P = 0.16), stroke (OR 1.81, 95% CI 0.81–4.08; P = 0.15), target vessel revascularization (TVR) (OR 1.54, 95% CI 0.98–2.42; P = 0.06), and target lesion revascularization (TLR) (OR 1.32, 95% CI 0.80–2.18; P = 0.28) were also not significantly different post PCI in the patients with T2DM with versus without OSA.ConclusionOSA was associated with a significant increase in all-cause mortality and MACEs post PCI in these patients with T2DM. Therefore, special care and continuous follow-up might be required for patients with T2DM with associated OSA after PCI. However, as a result of the limited number of participants, further larger studies would be required to confirm these hypotheses.

Are Sleep Questionnaires Valid in All Adult Age Groups as Screening Tools for Obstructive Sleep Apnea?

Background and Objectives: Evaluation of Epworth Sleepiness Scale (ESS), Berlin, STOP, and STOP-Bang questionnaire validities for obstructive sleep apnea (OSA) screening among various adult age groups.Materials and Method: Results for each of those questionnaires were compared with diagnostic overnight polysomnography (PSG) data obtained for 396 patients suffering either insomnia, sleep apnea, excessive daytime sleepiness, or chronic snoring who had been divided into three age groups (20-39, 40-59, or ≥60 years). For each questionnaire, the sensitivity, specificity, accuracy, and area under the curve (AUC) were calculated.Results: Among the OSA group [apnea hypopnea index (AHI) cutoff ＞5], Berlin and STOP questionnaire sensitivity and specificity were significantly different among the age groups. Among the moderate-to-severe OSA sub-group (AHI cutoff ＞15), the specificity of Berlin, STOP, and STOP-Bang questionnaire was significantly different among age groups.Conclusion: The Berlin and STOP questionnaires differed with patient age in OSA screening. The ESS questionnaire, by contrast, did not show any age-related differences of sensitivity and specificity in OSA screening or moderate-to-severe OSA screening.

Prediction of Apnea-Hypopnea Index Using Sound Data Collected by a Noncontact Device.

To predict the apnea-hypopnea index (AHI) in patients with obstructive sleep apnea (OSA) using data from breathing sounds recorded using a noncontact device during sleep. Prospective cohort study. Tertiary referral hospital. Audio recordings during sleep were performed using an air-conduction microphone during polysomnography. Breathing sounds recorded from all sleep stages were analyzed. After noise reduction preprocessing, the audio data were segmented into 5-second windows and sound features were extracted. Estimation of AHI by regression analysis was performed using a Gaussian process, support vector machine, random forest, and simple linear regression, along with 10-fold cross-validation. In total, 116 patients who underwent attended, in-laboratory, full-night polysomnography were included. Overall, random forest resulted in the highest performance with the highest correlation coefficient (0.83) and least mean absolute error (9.64 events/h) and root mean squared error (13.72 events/h). Other models resulted in somewhat lower but similar performances, with correlation coefficients ranging from 0.74 to 0.79. The estimated AHI tended to be underestimated as the severity of OSA increased. Regarding bias and precision, estimation performances in the severe OSA subgroup were the lowest, regardless of the model used. Among sound features, derivative of the area methods of moments of overall standard deviation demonstrated the highest correlation with AHI. AHI was fairly predictable by using data from breathing sounds generated during sleep. The prediction model may be useful not only for prescreening but also for follow-up after treatment in patients with OSA.

Phenotypic Labelling Using Drug-Induced Sleep Endoscopy Improves Patient Selection for Mandibular Advancement Device Outcome: A Prospective Study.

Mandibular advancement device (MAD) outcome varies between patients. We hypothesized that upper airway collapse sites, patterns, and degrees assessed during baseline drug-induced sleep endoscopy (DISE) affect MAD outcome. One hundred patients with obstructive sleep apnea (OSA) were included and underwent baseline type 1 polysomnography. MAD was fitted intraorally at fixed 75% maximal protrusion. A total of 72 patients completed 3-month follow-up polysomnography and baseline DISE. Response was defined as apnea-hypopnea index (AHI) reduction ≥ 50%, deterioration as AHI increases during MAD treatment compared to baseline. Adjusting for baseline AHI and body mass index, patients with tongue base collapse showed 3.69 higher odds (1.27-10.73; P = .0128) for response. Complete concentric collapse at the level of the palate (5.32 [1.21-23.28]; P = .0234) and complete laterolateral oropharyngeal collapse (6.62 [1.14-38.34]; P = .0330) related to deterioration. Results for tongue base collapse and complete concentric collapse at the level of the palate were confirmed in the moderate to severe OSA subgroup. Applying these results to this selected subgroup increased response rate with 54% and decreased deterioration rate with 53%. These results were confirmed using other response and deterioration definitions. Three baseline DISE phenotypes identified during drug-induced sleep were significantly related to MAD treatment outcome: one beneficial, tongue base collapse, and two adverse, complete concentric collapse at the level of the palate and complete laterolateral oropharyngeal collapse. If confirmed in future prospective studies, these results could guide patient selection for MAD outcome. This prospective clinical trial (PROMAD) was registered on Clinicaltrials.gov with identifier: NCT01532050. Op de Beeck S, Dieltjens M, Verbruggen AE, Vroegop AV, Wouters K, Hamans E, Willemen M, Verbraecken J, De Backer WA, Van de Heyning PH, Braem MJ, Vanderveken OM. Phenotypic labelling using drug-induced sleep endoscopy improves patient selection for mandibular advancement device outcome: a prospective study. J Clin Sleep Med. 2019;15(8):1089-1099.

Examining the Utility of a Novel Neurologic Test in Patients With Obstructive Sleep Apnea: A Pilot Study.

Purpose: To test the association between participant King-Devick Test (KDT) times and obstructive sleep apnea (OSA) severity and evaluate for improvement after continuous positive airway pressure (CPAP) treatment. Methods: Study dates January 30 to July 31, 2018. Patients were referred for initial evaluation of sleep disordered breathing concerns. OSA severities were defined by Apnea Hypopnea Index (AHI) results, with ≥15 considered at least moderate OSA. The KDT is an objective physical measure of brain function. We estimated correlation between KDT time and AHI and compared mean KDT time between patients with and without moderate OSA. For the OSA subgroup, we evaluated for potential improvement in KDT after CPAP. Results: We enrolled 60 participants, of whom 35 (58.3%) had OSA with an AHI ≥15. Initial analyses noted no significant KDT time differences between patients based on OSA severity. However, after excluding 3 participants who had baseline neurologic illness, adjusted analyses demonstrated that mean KDT time was significantly prolonged for patients with moderate or greater OSA (AHI ≥15) as compared to those with mild or no sleep apnea (AHI <15); 63.4 seconds (95% CI 58.9-67.8) versus 55.7 seconds (95% CI 50.2-61.1), P = .03. CPAP-treated subjects demonstrated significantly improved KDT test times; 63.5 seconds mean pretreatment versus 55.6 posttreatment; −6.6 seconds mean difference, 95%CI (−12.0, −1.13), P = .02. Conclusion: Neurologic abnormalities in patients with OSA are potentially demonstrable utilizing this objective physical measure. Significant improvement is achieved in patients after CPAP treatment.

Obstructive Sleep Apnea and Sleep Architecture in Adolescents With Severe Obesity: Effects of a 9-Month Lifestyle Modification Program Based on Regular Exercise and a Balanced Diet.

Physical exercise and lifestyle modification are recognized as adjunct therapy for obstructive sleep apnea (OSA) in overweight adults. The objectives of this study were to investigate the effects of long-term physical exercise combined with a balanced diet on sleep architecture, sleep duration, and OSA in adolescents with severe obesity. This interventional study was conducted in a nursing institution. Participants were aged 14.6 ± 1.2 years with obesity (body mass index (BMI) = 40.2 ± 6.5 kg/m2). At admission and at 9 months, participants underwent ambulatory polysomnography and incremental maximal exercise testing to determine cardiorespiratory fitness. Twenty-four subjects completed the study. Analyses were performed on the whole population and on a subgroup of subjects with OSA (OSA-subgroup). OSA, defined as obstructive apnea-hypopnea index (OAHI) ≥ 2 events/h, was diagnosed in 58.3% of the population. OAHI was only associated with fat mass in males (r = .75, P < .05). At 9 months postintervention, weight loss (-11.1 kg, P < .0001) and improved cardiorespiratory fitness (VO2peak: +4.9 mL/min/kg, P < .001) were found in the whole population. Sleep duration was increased (+34 minutes, P < .05) and sleep architecture was changed with an increase of rapid eye movement sleep (+2.5%, P < .05) and a decrease of stage N3 sleep (-3.1%, P < .001). Similar results were found in the OSA subgroup. However, OAHI remained unchanged (P = .18). A combination of supervised aerobic exercise and a balanced diet led to weight loss, improved aerobic capacity, and modified sleep architecture without changes in OSA. A commentary on this article appears in this issue on page 907. Registry: ClinicalTrials.gov, Title: Exercise and Venous Compression on Upper Airway Resistance in Obese Teenagers With OSA (OBESOMAC), URL: https://clinicaltrials.gov/ct2/show/NCT02588469, Identifier: NCT02588469.

Short-term expiratory muscle strength training attenuates sleep apnea and improves sleep quality in patients with obstructive sleep apnea

This study investigated the effects of 5 weeks of expiratory muscle strength training (EMST) on sleep apnea, sleep quality, and respiratory muscle strength in patients with different levels of obstructive sleep apnea (OSA). Twenty-five outpatients who received a diagnosis of OSA participated in the study and were assigned to either the EMST group (n=13) or control group (CTRL, n=12). The training intensity for the EMST group was 75% of the maximum static expiratory (PEmax) score (5days/week). The PEmax, apnea–hypoapnea index (AHI), Epworth Sleepiness Scale (ESS), and Pittsburgh Sleep Quality Index (PSQI) scores were evaluated before and after the treatment. EMST improved the scores for AHI (−40%), PEmax (+68%), and PSQI (−28%) and reduced the PSQI scores of the moderate OSA subgroup but not the mild OSA subgroup. The percent changes (Δ%) in the AHI and PEmax scores of participants with OSA were negatively correlated. We demonstrated that EMST effectively improved sleep apnea, sleep quality, and expiratory muscle strength in participants with OSA. Participants with moderate OSA exhibited greater improvement than did those with mild OSA, and the improvement in PEmax scores was correlated with a decrease in sleep apnea.

Fatigue and serum testosterone in obstructive sleep apnea patients.

Obstructive sleep apnea (OSA)-related fatigue is a common understudied symptom. Fatigue is associated with low serum testosterone level in non-OSA patients. No data are available about this association in OSA patients. To investigate in adult obese males affected by OSA, the relationship between fatigue and serum testosterone in order to identify predictors for OSA-related fatigue. Fifteen OSA patients and 15 control subjects participated. The parameters analyzed were serum testosterone morning concentration, polysomnography parameters, daytime sleepiness (Epworth Sleepiness Scale) and fatigue (Multidimensional Fatigue Inventory). Regression test was applied in order to show predictors of fatigue. Kruskal-Wallis test followed by post-hoc analysis was performed to test for differences between controls and OSA subgroups for testosterone, fatigue components and sleepiness. Mean testosterone level was 3.55 ± 0.7 ng/mL in the OSA group, significantly lower than in controls (4.26 ± 1.1 ng/mL, P = 0.049). An inverse correlation was found between testosterone and fatigue scores (P < 0.01). Furthermore, a statistically significant difference was found between the control group and the severe OSA subgroup for general fatigue, physical fatigue, reduced activity and mental fatigue. However, no significant differences were found between controls and mild OSA. Among all variables, testosterone was the only independent significant predictor of physical fatigue (t = -2.56, P = 0.033, R = 0.978, R(2) = 0.958) and reduced activity (t = -4.41, P = 0.002, R = 0.966, R(2) = 0.934) in the OSA patients. OSA-related fatigue was strongly associated with serum testosterone, together with OSA severity.

Selection of response criteria affects the success rate of oral appliance treatment for obstructive sleep apnea

BackgroundIn oral appliance therapy for obstructive sleep apnea (OSA), treatment success is arbitrarily defined. We investigated if the selection of response criteria affected the success rate of oral appliance treatment. MethodsThe effects of an oral appliance on apnea–hypopnea index (AHI) and nadir percutaneous oxygen saturation (SpO2) were investigated in 224 OSA patients. Treatment success was defined as a reduction in AHI to <5events per hour with a >50% reduction in baseline AHI (criterion 1), a follow-up AHI of <10events per hour with a >50% reduction in baseline AHI (criterion 2), a >50% reduction in baseline AHI alone (criterion 3), or a >50% reduction in baseline AHI with the nadir SpO2 above 90% (criterion 4). ResultsThe baseline AHI was reduced with an oral appliance in place compared with the follow-up value (23±11–8.5±8.7events/h; P<.05) in all of the participants. In every OSA subgroup, the success rate under criterion 3 (75% [mild], 71% [moderate], and 70% [severe]) was greater than that under criterion 1 (53%, 40%, and 24%, respectively). However, responders under criterion 3 in the severe OSA subgroup were still hypoxemic with a nadir SpO2 of 87±8% even after treatment. This situation was improved by the use of criterion 4, in which a satisfactory improvement in AHI (from 38±11 to 1±1events/h; P<.01) was associated with a sufficient increase in the nadir SpO2 (93±2%). ConclusionsWe conclude that the selection of response criteria influences the success rate of oral appliance treatment. To avoid adverse health outcomes, an adjunct definition of treatment success using SpO2 may be effective for patients who have more severe OSA.

The effect of childhood obstructive sleep apnea on ambulatory blood pressure is modulated by the distribution of respiratory events during rapid eye movement and nonrapid eye movement sleep

ObjectiveWe aimed to investigate if different childhood obstructive sleep apnea (OSA) subtypes, namely rapid eye movement (REM)-related, nonrapid eye movement (NREM)-related and stage-independent OSA would exert different effects on ambulatory blood pressure (ABP). MethodsData from our previous school-based cross-sectional study were reanalyzed. Subjects who had an obstructive apnea–hypopnea index (OAHI) between 1 and 10 events per hour and a total REM sleep duration of >30min were included in our analysis. REM-related and NREM-related OSA were defined as a ratio of OAHI in REM sleep (OAHIREM) to OAHI in NREM sleep (OAHINREM) of >2 and <0.5, respectively. The others were classified as stage-independent OSA. ResultsA total of 162 subjects were included in the analysis. In the mild OSA (OAHI, 1–5events/h) subgroup, no significant differences in any ABP parameters were found between OSA subtypes. On the other hand, in subjects with moderate OSA (OAHI, 5–10events/h), the REM-related OSA subtype had a significantly lower daytime systolic blood pressure (SBP) z score (−0.13±0.90 cf 1.15±0.67; P=.012) and nighttime SBP z score (0.29±1.06 cf 1.48±0.88, P=.039) than the stage-independent OSA subtype. Linear regression analyses revealed that OAHINREM but not OAHIREM was significantly associated with both daytime (P=.008) and nighttime SBP (P=.042) after controlling for age, gender, and body size. ConclusionChildren with obstructive events mainly in REM sleep may have less cardiovascular complications than those with stage-independent OSA.

Analysis of obstructive sleep apnea patients with “sawtooth sign” on the flow-volume curve

The aims of the present study are to determine whether there is an obstructive sleep apnea (OSA) subgroup presenting with sawtooth sign on the spirometric flow-volume curve, and to identify the clinical importance of the sawtooth sign in these patients. The study subjects consisted of 134 OSA patients (≥18 years) whose spirometric tests were made on the same day with the polysomnography. Patients without sawtooth sign were taken as the control group. Patients with sawtooth sign and control subjects were retrospectively analyzed in terms of distinctive demographic, anthropometric, polysomnographic, and spirometric characteristics. OSA patients with sawtooth sign (n = 36) had greater neck circumference and body weight, and were taller than control subjects (n = 98). Patients with sawtooth sign were mainly males (p < 0.01). Female/male ratios were similar in control subjects. The presence of coronary artery disease was higher (p = 0.024), and current smokers were more (p = 0.014) among the patients with sawtooth sign than control subjects. In logistic regression analysis, the presence of sawtooth sign and age were the only statistically significant parameters (p = 0.028 and p = 0.002, respectively) that affect the likelihood of coronary artery diseases. There were no differences among the groups with regard to age, BMI, wrist circumference, and other comorbid conditions. The duration time of oxygen desaturation (<90%), avarage, and longest duration of total apnea were longer (p = 0.050, p = 0.034 and p = 0.014, respectively) and the obstructive apnea index was more (p = 0.035) in OSA patients with sawtooth sign when compared to control subjects. There were no differences with regard to other polysomnographic parameters, sleep architecture, Epworth sleepiness score, and spirometric parameters. As an OSA subgroup, the OSA patients with sawtooth sign may have more frequent and longer duration of obstructive apneas, longer duration time of oxygen desaturation, and greater risk for the coronary artery disease.

Einfluss der Adaptiven Servoventilation auf das BNP bei Patienten mit Cheyne-Stokes-Atmung und leicht- bis mittelgradiger systolischer und diastolischer Herzinsuffizienz

CPAP therapy has a variable effect on central sleep apnea with Cheyne-Stokes respiration (CSA-CSR). Adaptive servoventilation (ASV) is more effective in normalising breathing in patients with heart failure. We hypothesised that, by normalising AHI, ASV reduces elevated BNP levels in patients with mild systolic and diastolic heart failure. From April 2004 to October 2006, patients with CSA-CSR with and without concomitant obstructive sleep apnea (OSA), clinical evidence of heart failure, regardless EF, and elevated BNP levels (> 100 pg/mL) were selected for treatment with ASV, unless CPAP therapy had reduced AHI to < 15 per hour of sleep. Follow-up polysomnographies and BNP analyses were performed after 6 weeks. 15-male patients (AHI 48.3 +/- 14.6/h) fulfilled all inclusion criteria; 7 patients had CSA-CSR + OSA, 8 had CSA-CSR. After 6 weeks of ASV, BNP decreased from 415 +/- 196 pg/mL to 264 +/- 146 pg/mL (p = 0.0009). There was only a significant BNP reduction in the CSA-CSR+OSA subgroup (p = 0.0002). ASV can normalise AHI in patients with mild systolic and diastolic heart failure and CSA-CSR +/- OSA, thus leading to a significant reduction of BNP levels. These findings suggest that effective suppression of sleep apnoea in such heart failure patients improves cardiac function.

Change in periodic limb movement index during treatment of obstructive sleep apnea with continuous positive airway pressure.

The following hypotheses were investigated: 1) severe obstructive sleep apnea (OSA) can mask concurrent periodic limb movement (PLM) disorder (PLMD), which becomes evident or worsens after treatment with continuous positive airway pressure (CPAP); 2) in patients with mild OSA, PLMs are not masked but may be triggered by subclinical hypopneas or respiratory effort-related arousals and improve after CPAP. Retrospective analysis was performed on 2 polysomnographic studies per patient--1 baseline, the second with CPAP titration. The apnea-hypopnea index (AHI) and PLM index (PLMI) under the 2 conditions were statistically analyzed. University hospital sleep disorders center. Patients were selected if they had a baseline AHI of 5 or greater and CPAP titration resulted in reduced AHI. Also, each needed to have either a PLMI of 5 or greater on baseline PSG or during CPAP titration. Patients who started or discontinued a medication that could affect PLMs after the baseline PSG were excluded. As clinically indicated, CPAP for OSA. Eighty-six patients qualified and were divided into 3 groups based on OSA severity. Significant correlations (P < 0.05) were found between AHI and PLMI on the baseline PSG (-0.50), between AHI on baseline PSG and PLMI on CPAP titration (0.49), and between PLMI on baseline PSG and on CPAP titration (-0.21). The increase in PLMI during CPAP titration in patients with severe OSA was statistically significant (P < 0.001). The PLMI decreased with CPAP in 20 of 86 patients, mostly in the mild OSA subgroup. Regression of post-CPAP reduction of AHI and change in PLMI yielded a significant logarithmic relationship (R2 = 0.3042). Severity of OSA may determine the effect of CPAP on PLMs. The PLMs may increase in moderate to severe OSA due mainly to "unmasking" of underlying PLMD. The PLMs may decrease in mild OSA post-CPAP due to resolution of PLMs associated with respiratory effort-related arousals. This suggests that PLMs may have more than 1 etiology and may be categorized as spontaneous (as in PLMD) and induced (when secondary to respiratory effort-related arousals).