Could non-HDL-cholesterol be a better marker of atherogenic dyslipidemia in obstructive sleep apnea?

Background/objectiveObstructive sleep apnea (OSA) is independently associated with dyslipidemia, a surrogate marker of atherosclerosis. Low-density lipoprotein (LDL)-cholesterol is accepted as a major independent risk factor for cardiovascular disease. However, non-high-density lipoprotein (HDL)-cholesterol is a better marker of atherogenic dyslipidemia and recommended as a target of lipid lowering therapy. We aimed to assess the prevalence of atherogenic dyslipidemia, and relationship between OSA severity and serum LDL-cholesterol and non-HDL cholesterol levels in OSA patients.MethodsWe retrospectively evaluated treatment naïve 2361 subjects admitted to the sleep laboratory of a university hospital for polysomnography. All subjects’ lipid profile including total cholesterol, LDL-cholesterol, HDL-cholesterol, triglycerides, and non-HDL-cholesterol were measured.ResultsOut of 2361 patients (mean age 49.6 ± 11.9 years; 68.9% male, apnea-hypopnea index 36.6 ± 28.4/h), 185 (7.8%) had no OSA and 2176 (92.2%) had OSA. Atherogenic dyslipidemia prevalence was high (57–66%) in OSA patients, and especially increased in severe OSA compared to other groups (p < 0.05). Though total and LDL-cholesterol did not differ between those with and without OSA, non-HDL-cholesterol (p = 0.020), and triglycerides (p = 0.001) were higher and HDL-cholesterol levels (p = 0.018) were lower in OSA patients than non-OSA. Non-HDL-cholesterol was significantly correlated with OSA severity (p < 0.001) and hypoxia parameters (p < 0.01), whereas LDL-cholesterol showed no correlation.ConclusionsAtherogenic dyslipidemia is highly prevalent and non-HDL-cholesterol levels are significantly increased, predominantly in severe OSA patients. Non-HDL-cholesterol but not LDL-cholesterol, is significantly correlated with OSA severity and hypoxia parameters. Therefore, it could be better to use non-HDL-cholesterol, which is a guideline recommended target of lipid therapy, as a marker of atherosclerotic cardiovascular risk in OSA patients.     

Prevalence and neurophysiological correlates of sleep disordered breathing in pediatric type 1 narcolepsy

Study objectivesTo investigate the prevalence and neurophysiological correlates of obstructive sleep disordered breathing (OSA) in type 1 narcolepsy (NT1) children and adolescents.MethodsThirty-eight, drug-naïve, NT1 children and adolescents and 21 age- and sex-balanced clinical controls underwent nocturnal polysomnography (PSG) and multiple sleep latency test (MSLT). According to the rules for pediatric population, an obstructive apnea-hypopnea index (Obstructive AHI) ≥ 1 (comprising obstructive and mixed events), defined comorbid OSA.ResultsNT1 children showed higher prevalence of overweight/obesity and severe nocturnal sleep disruption (lower sleep efficiency, and increased N1 sleep stage percentage) coupled with higher motor activity (periodic limb movement index [PLMi] and REM atonia index) compared to clinical controls. Sleep-related respiratory variables did not differ between NT1 and clinical controls (OSA prevalence of 13.2% and 4.8%, respectively). NT1 children with OSA were younger and showed lower N2 sleep stage percentage and higher PLMi than NT1 children without comorbid OSA. Overweight/obesity was not associated with OSA in NT1.ConclusionsDespite higher body mass index (BMI), OSA prevalence did not differ between children with NT1 and clinical controls. OSA in pediatric NT1 patients is a rare and mild comorbidity, further contributing to nocturnal sleep disruption without effects on daytime sleepiness.     

Diagnostic approach to sleep disordered-breathing among patients with grade III obesity

Sleep apnea test (SAT) is a cost-effective approach to evaluate subjects without associated comorbidities suspected for obstructive sleep apnea (OSA), a disorder particularly common in obese subjects. The association of obesity with awake hypercapnia (carbon dioxide arterial pressure, PaCO₂ ≥45 mmHg) defines the obesity-hypoventilation syndrome (OHS), which in turn results in increased morbidity and mortality compared to simple OSA. Isolated hypoventilation during sleep in obese patients (obesity-related sleep hypoventilation, ORSH) is now considered as an early stage of OHS. The aim of this study was to assess the performance of SAT in diagnosing OSA and predicting the presence of ORHS among patients with grade III obesity without awake hypercapnia.MethodsOver a 14-months period, patients with grade III obesity (body mass index≥40 kg/m²) presenting moderate-to-severe OSA (apnea-hypopnea index [AHI]≥15) upon SAT and normal awake PaCO₂ at arterial blood gas analysis, systematically underwent in-lab nocturnal polysomnography combined with transcutaneous carbon dioxide pressure (PtcCO₂) monitoring.ResultsAmong 48 patients included in the study, 16 (33%) presented an AHI<15 upon polysomnography and 14 (29%) had ORSH. The test revealed no difference in ORSH prevalence between patients with AHI <15 or ≥15 (31% vs. 25%). No SAT variables were independently associated with increased PtCO₂.ConclusionsThis study shows that SAT overestimates OSA severity and ORSH affects one third of patients with grade III obesity without awake hypercapnia and with moderate-to-severe OSA at SAT, suggesting how polysomnography combined with PtCO₂ monitoring is the most appropriate diagnostic approach for OSA and ORSH in this population.     

Clinical and polysomnographic predictors of severe obstructive sleep apnea in the South Indian population

Background:With the emergence of lifestyle diseases in epidemic proportions, obstructive sleep apnea (OSA) is being increasingly recognized in less developed countries as well.Aim:We sought to study the demographic, clinical, and polysomnographic (PSG) predictors of OSA severity in a cohort of South Indian patients.Results:There were 152 (119 males and 33 females) subjects with a mean age of 53.8 years and body mass index (BMI) of 29.31. Mean AHI was 36.2/h (range: 5.1-110) and 66 subjects had severe OSA. Around 12% had the presenting complaint as insomnia, mainly of sleep maintenance. Of the subjects, 35% had witnessed apneas and 67% had excessive daytime sleepiness (EDS); 40% of patients had ≥2 risk factors. PSG parameters showed short sleep onset latency with a high arousal index. Mean apnea duration was 24.92 s. We found that age >55 years, BMI >25 kg/m², witnessed apneas, EDS, hypertension, dyslipidemia, reduced slow wave sleep duration, mean apnea duration >20 s, and desaturation index >10/h correlated well with OSA severity while the arousal index, sleep latency and efficiency, and exposure to smoking and alcohol showed no association.Conclusions:Older subjects with witnessed apneas are likely to have more severe OSA. Even though overall sleep architecture was similar between the groups, severe OSA had shorter slow wave sleep, longer apneas, and higher nocturnal hypoxemia.     

Obstructive sleep apnea during acute coronary syndrome is related to myocardial necrosis and wall stress

BackgroundThe relative contribution of pathophysiological mechanisms in acute coronary syndrome (ACS) towards obstructive sleep apnea (OSA) is not well-studied. We examined the correlation between severity of OSA and inflammation, myocardial necrosis, wall stress, and fibrosis.MethodsA total of 89 patients admitted with ACS underwent a sleep study during index admission. Plasma levels of high-sensitivity C-reactive protein (hs-CRP), troponin I, N-terminal pro-brain natriuretic peptide (NT-proBNP), and suppression of tumorigenicity 2 (ST2) were prospectively analyzed. Two patients diagnosed with central sleep apnea were excluded.ResultsThe recruited patients were divided into no (AHI <5 events/hour, 9.2%), mild (5-<15, 27.6%), moderate (15-<30, 21.8%), and severe (≥30, 41.4%) OSA. Compared to the no, mild and moderate OSA groups, the severe OSA group had a higher body mass index (p = 0.005). They were also more likely to present with ST-segment elevation ACS (versus non-ST-segment elevation ACS) (p = 0.041), have undergone previous coronary artery bypass grafting (p = 0.013), demonstrate complete coronary occlusion during baseline coronary angiography (p = 0.049), and have a larger left atrial diameter measured on echocardiography (p = 0.029). Likewise, the severe OSA group had higher plasma levels of hs-CRP (p = 0.004), troponin I (p = 0.017), and NT-proBNP (p = 0.004), but not ST2 (p = 0.10). After adjustment for the effects of confounding variables, OSA was independently associated with troponin I (ie, myocardial necrosis; p = 0.001) and NT-proBNP (ie, myocardial wall stress; p = 0.008).ConclusionSevere OSA during the acute phase of ACS was associated with extensive myocardial necrosis and high myocardial wall stress, but not with inflammation and myocardial fibrosis.     

Obstructive sleep apnea,sleep duration and chronic kidney disease in patients with coronary artery disease

BackgroundLimited evidence is available addressing the potential role of sleep disorders on renal function. Here, we aimed to explore the associations of obstructive sleep apnea (OSA) and sleep duration (SD) with renal function in subjects with high cardiovascular risk.MethodsConsecutive subjects with coronary artery disease (CAD) underwent clinical evaluation, sleep study to define OSA and one-week wrist actigraphy to objectively measure SD. OSA was defined by an apnea-hypopnea index (AHI) of ≥15 events/hour. The estimated glomerular filtration rate (eGFR) was calculated using the CKD-EPI equation. We analyzed the associations of OSA and SD with continuous eGFR values and according to the presence of CKD (eGFR<60 mL/min/1.73 m²) after adjusting for multiple confounding factors.ResultsWe studied 242 subjects (62.8% men). The frequency of OSA was 55.4% and the median SD was 412.8 (363.4–457.25) min. There was no difference in the eGFRs between participants with and without OSA (69.3 ± 19.1 vs. 74.6 ± 19.3 mL/min/1.73 m², p = 0.72) and the rate of eGFR <60 mL/min/1.73 m² (34.3% vs. 25.9%; p = 0.21). Similarly, we did not find differences in patients in eGFR for those with SD ≥ 6 h versus SD < 6 h (72.5 ± 20.3 vs. 71.4 ± 19.1 mL/min/1.73 m², p = 0.72). In the linear regression analysis, AHI was independently associated with an eGFR<60 mL/min/1.73 m² in the unadjusted model [−0.15 (-0.27 to −0.04)], (P = 0.01), but not in the adjusted models. Analyses of continuous SD or the stratification in SD ≥ 6 h or <6 h also revealed neutral results on eGFR.ConclusionOSA severity and SD were not independently associated with CKD in subjects with CAD.     

Effects of an individualized exercise training program on severity markers of obstructive sleep apnea syndrome: a randomised controlled trial

ObjectiveObstructive sleep apnea (OSA) is a high prevalent disorder with severe consequences including sleepiness, metabolic, and cardiovascular disorders. The aim of this study was to assess the effect of an individualized exercise-training (IET) program with educational sessions vs educational sessions alone on severity markers of OSA over an eight-week duration.MethodsThis was a randomised, controlled, parallel-design study. In sum, 64 patients with moderate-to-severe OSA (apnea-hypopnea index AHI 15–45/hour), low physical activity level (Voorrips<9), body-mass index (BMI) <40 kg/m² were included in intervention group (IG) or control group (CG), and 54 patients finished the study. All underwent polysomnography (PSG), multiple sleep latency test (MSLT), constant workload exercise test, blood samples and fulfilled questionnaires twice. The primary endpoint was the change in apnea-hypopnea (AHI) at eight weeks from baseline. Main secondary endpoints were daytime sleepiness assessed by questionnaire and objective tests.ResultsNo significant between-group differences were found for changes in AHI. A reduction in AHI was found in IG only (p = 0.005). Compared to CG, exercise training leads to a greater decrease in AHI during REM sleep (p = 0.0004), with a significant increase in mean daytime sleep latency (p = 0.02). Between-group differences were significant for weight reduction, severity of fatigue, insomnia and depressive symptoms with trend for sleepiness symptoms.ConclusionsIn adult patients with moderate-to-severe OSA, IET did not decrease AHI compared to the control group but improved markers of severity of OSA, in particular AHI in rapid eye movement (REM) sleep and objective daytime sleepiness. Adding personalized exercise training to the management of patients with OSA should be considered.ClinicalTrials.gov identifierNCT01256307.     

Sleep positions in children with Down syndrome and obstructive sleep apnea

ObjectivesTo assess sleep positions in children with both Down syndrome (DS) and obstructive sleep apnea (OSA) and determine if there is a preferred sleep position by severity of apnea.MethodsA single-center retrospective review of patients with both DS and OSA was performed. Caregivers reported sleep position utilized greater than 50% of observed sleep time. Accuracy of this report was confirmed through review of hypnograms from polysomnography studies.ResultsEighty-two patients met inclusion criteria. Median body mass index (BMI) was 26.6 and 56% of patients had a prior tonsillectomy and/or adenoidectomy. The mean obstructive AHI (OAHI) was 25.33 with 90.4% having severe OSA, 9.6% having moderate OSA, and no patients having mild OSA. Reported sleep positions were skewed towards lateral/decubitus (82.9%) compared to prone (11.0%) and supine (6.1%). This was consistent with hypnogram data where 71% of total sleep time in lateral/decubitus positions compared to prone (13%) and supine (6%). The median changes in sleep position per patient was 5 (IQR: 3–6). Lower BMI (p < 0.001, 95% CI: 0.32–1.13) and tonsillectomy (p < 0.001, 95% CI: 7.7–18.19) were associated with lower OAHI. Sleep position was not associated with age (p = 0.19), sex (p = 0.66), race (p = 0.10), ethnicity (p = 0.68) nor history of tonsillectomy (p = 0.34). Preferred sleep position was not correlated with OAHI (p = 0.78, r = 0.03) or OSA severity (p = 0.72, r = 0.03).ConclusionsThis study highlights the possibility that children with DS may have preferential sleep positions that cater to optimized airflow in the context of OSA although further prospective study is needed.     

Impact of smoking on sleep macro– and microstructure

ObjectivesExisting data suggest that smoking may be associated with sleep disturbances. This study aimed to determine the association between smoking and both subjective and objective sleep quality.MethodsCross-sectional analysis of sleep characteristics in 3233 participants from the population-based CoLaus-HypnoLaus cohort (52.2% women, mean age 56.6 ± 10.2 years) who completed questionnaires on sleep quality, of whom 1489 (46%) had a full polysomnography. Smoking data were self-reported; participants were classified by smoking status as current, former or never smokers. Primary outcomes were subjective sleep quality assessed by sleep questionnaires, and objective sleep quality based on polysomnography (sleep macrostructure), including power spectral analysis of the electroencephalogram on C4 electrode (sleep microstructure), quantifying the relative amount of delta power (1–4 Hz), a marker of sleep depth, and arousal-associated alpha power (8–12 Hz).ResultsCurrent smokers had a shift toward faster sleep electroencephalogram activity with lower delta power in non-REM sleep compared with former and never smokers (−2.8 ± 0.4% and −2.4 ± 0.4%, respectively; both p < 0.001) and higher alpha power (+0.8 ± 0.2%; p < 0.001) compared with never smokers. There was a dose-dependent negative association between electroencephalogram delta power and smoking intensity (r² = −1.2 [–1.9, −0.5]; p = 0.001). Additionally, mean nocturnal oxygen saturation was lower in current smokers.ConclusionsCurrent smokers had decreased objective sleep quality, with a dose-dependent association between smoking intensity and decrease in electroencephalogram delta power during non-REM sleep, in addition to an increase in alpha power. Considering the importance of sleep quality for wellbeing and health, these results provide further data to support smoking cessation.     

Effect of myofunctional therapy on children with obstructive sleep apnea: a meta-analysis

ObjectiveTo systematically review the current literature for articles describing the effect of myofunctional therapy on pediatric obstructive sleep apnea (OSA) and to perform a meta-analysis on the sleep study data.MethodsThree authors (A.B., K.K. and M.C.) independently searched from inception through April 20, 2020 in PubMed/MEDLINE, Scopus, Embase, Google Scholar and The Cochrane Library. Mean difference (MD), standard deviations and 95% confidence intervals were combined in the meta-analysis for apnea-hypopnea index (AHI), mean oxygen saturations, and lowest oxygen saturations (nadir O2).Results10 studies with 241 patients met study criteria and were further analyzed. The AHI reduced from 4.32 (5.2) to 2.48 (4.0) events/hr, a 43% reduction. Random effects modeling demonstrated a mean difference in AHI of −1.54 (95% CI -2.24,-0.85)/hr, z-score is 4.36 (p < 0.0001). Mean oxygen saturation increased by 0.37 (95% CI 0.06,0.69) percent, z-score is 2.32 (p = 0.02). There was no significant increase in nadir O2.ConclusionsDespite heterogeneity in exercises, myofunctional therapy decreased AHI by 43% in children, and increased mean oxygen saturations in children with mild to moderate OSA and can serve as an adjunct OSA treatment.     

Nocturnal heart rate variation in diabetic and non-diabetic patients with sleep apnea syndrome

ObjectivesHeart rate variability (HRV) analysis is used for the evaluation of autonomic function in the cardiovascular system. Decreased HRV is associated with disorders affecting the autonomous system such as diabetes mellitus (DM) and obstructive sleep apnea (OSA). Previous studies have shown an association between OSA and DM. However, the interrelationships of HRV with OSA and DM are not well known. The aim of this study was to assess nocturnal HRV in patients who suffered from OSA with and without DM.MethodsSixty patients with OSA (27 with DM and 33 non-DM) underwent polysomnography for eight hours starting at midnight. From electrocardiogram (ECG) recordings taken as a part of polysomnography, time-domain and frequency-domain HRV parameters were evaluated to compare patients with regard to nocturnal HRV components such as low frequency (LF) and high frequency (HF), apnea–hypopnea index (AHI) and sleep parameters.ResultsIn the non-DM group, a direct relationship was observed between AHI and HRV rather than very low frequency (VLF) and LF/HF variables. This relationship was just significant between AHI and standard deviation of five-min average of normal R–R intervals and adjacent R–R intervals differing by 0.50 ms over 24 h (p < 0.05). In the DM group, the correlation between AHI and HRV parameters except HF and waking frequency was direct and non-significant. Intergroup comparison showed a significant difference between groups regarding AHI and HRV-index, LF and VLF (p < 0.05).ConclusionsDM can affect HRV; however, this is not the case in OSA patients. This means that in the presence of OSA, the DM effect on HRV disappears.     

Spontaneous improvement in both obstructive sleep apnea and cognitive impairment after stroke

BackgroundKnowledge available about the relationship between obstructive sleep apnea (OSA) and cognitive impairment after stroke is limited. The evolution of OSA and cognitive performance after stroke is not sufficiently described.MethodsWe prospectively enrolled and examined acute stroke patients without previously diagnosed OSA. The following information was collected: (1) demographics, (2) sleep cardio-respiratory polygraphy (PG) at 72 h, day seven, month three, and month 12 after stroke, (3) post-stroke functional disability tests at entry and at months three and 12, and (4) cognition (attention and orientation, memory, verbal fluency, language, and visual-spatial abilities) using the revised Addenbrooke's Cognitive Examination (ACE-R) at months three and 12.ResultsOf 68 patients completing the study, OSA was diagnosed in 42 (61.8%) patients. The mean apnea/hypopnea index (AHI) at study entry of 21.0 ± 13.7 spontaneously declined to 11.6 ± 11.2 at month 12 in the OSA group (p < 0.0005). The total ACE-R score was significantly reduced at months three (p = 0.005) and 12 (p = 0.004) in the OSA group. Poorer performance on the subtests of memory at months 3 (p = 0.039) and 12 (p = 0.040) and verbal fluency at months 3 (p < 0.005) and 12 (p < 0.005) were observed in the OSA group compared to non-OSA group. Visual-spatial abilities in both the OSA (p = 0.001) and non-OSA (p = 0.046) groups and the total ACE-R score in the OSA (p = 0.005) and non-OSA (p = 0.002) groups improved.ConclusionsA high prevalence of OSA and cognitive decline were present in patients after an acute stroke. Spontaneous improvements in both OSA and cognitive impairment were observed.     

Relationship between reflux diseases and obstructive sleep apnea together with continuous positive airway pressure treatment efficiency analysis

BackgroundObstructive sleep apnea (OSA) is known to be highly associated with reflux diseases. There is evidence that continuous positive airway pressure (CPAP) can decrease the clinical symptoms of gastroesophageal reflux (GER) in OSA patients, but whether CPAP can decrease nocturnal laryngopharyngeal reflux (LPR) episodes is still lack of strong evidence.ObjectiveTo investigate the efficiency of CPAP on LPR and the relationship between LPR, GER and OSA.Study designretrospective study.MethodsForty adult patients who had confirmed OSA by polysomnography and suspected LPR were enrolled. Their results of synchronous polysomnography and 24 h esophageal and oropharyngeal Dx-pH monitoring were analyzed. Twenty-seven OSA patients were treated with CPAP on the second night. The nocturnal reflux parameters with and without CPAP treatment were compared.Results15.0% and 42.5% of OSA patients were associated with LPR and GER through Dx-pH monitoring respectively. Nevertheless, more than one reflux attack falling below pH6.0 of oropharynx during sleep time was detected in 80.0% patients. There was a significant inverse correlation between the lowest/mean pH values of oropharynx and obstructive apnea index (OAI), so was the lowest pH values of esophagus. Significant positive correlation was calculated between the total number of reflux episodes below pH6.0 of oropharynx and apnea–hypopnea index (AHI)/OAI/hypopnea index (HI). A similar positive correlation was also significant between AHI/OAI and GER parameters. The assessment of the efficacy of CPAP treatment showed significant difference both in GER and LPR related parameter.ConclusionsOSA patients have a higher incidence of nocturnal LPR and GER. CPAP treatment can effectively reduce both GER and LPR attacks while disordered sleep events reduced in OSA patients.     

Association between nondipping pattern and EndoPAT signal in patients with mild obstructive sleep apnea

ObjectiveTo compare vascular endothelial function between dipping (D) and nondipping (ND) patterns in patients with and without mild obstructive sleep apnea (OSA) using EndoPAT, a test of reactive hyperemia used to assess peripheral vascular endothelial function.MethodsThe sample consisted of individuals of both genders between 18 and 65 years of age with a body mass index (BMI) of ≤35 kg/m² and apnea/hypopnea index (AHI) of ≤15. The nondipping pattern was considered present when the dip of nocturnal blood pressure (NBP) was <10%. All of the sample underwent clinical and physical evaluation, full polysomnography, 24-hour ambulatory blood pressure monitoring, and EndoPAT evaluation. A generalized linear model was used for statistical analysis.ResultsThe sample comprised 120 individuals, 35 in the control group and 85 in the mild OSA group. Four groups were formed: Control-ND, Control-D, Mild OSA-ND, and Mild OSA-D according to nocturnal ABPM patterns. The frequency of nondipping was (34.1%) in the Mild OSA group and (17.1%) in the Control group (p = 0.07). The Mild OSA-ND group had a higher augmentation index (AIx) than the Mild OSA-D group. Regression analysis showed that male gender, higher age, and nondipping status were associated with these results, whereas oxygen desaturation index (ODI) and AHI did not. With respect to the reactive hyperemia index (RHI), the Mild OSA-D group had lower values compared to the Control-ND group, but an association with OSA was not confirmed in the regression model.ConclusionNondipping status was associated with a worse augmentation index in both groups independently of AHI or oxygen desaturation index. Male gender, higher age, and nondipping status were associated with augmentation index.ClinicalTrials.gov Identifier: NCT01461486.     

Age-specific markers of adiposity in patients with obstructive sleep apnea

ObjectivesAdiposity can have varying effects on the individual depending upon its distribution pattern. We assessed age-related distribution of adipose tissue by anthropometric measures and bioelectrical impedance analysis, as well as their association with obstructive sleep apnea (OSA) severity.MethodsParticipants were 169 elderly (aged ≥ 65 years) and 142 non-elderly (aged < 65 years) referred for overnight polysomnography. The associations between obesity parameters and apnea-hypopnea index (AHI) were determine by univariate and multivariate linear regression analyses. Area under receiver operating characteristic curve (AUC) was used to access the predicting performance of some parameters.ResultsCompared with non-elderly, elderly showed higher conicity index and visceral adiposity (VA)/subcutaneous adiposity (SA), lower body mass index (BMI), neck circumference, waist circumference, hip circumference and SA. Multiple regression analyses revealed that VA and VA/SA were independently associated with AHI in elderly (explained 17.2% of the AHI ^0.5 variability), while BMI and VA/SA were independently associated with AHI in non-elderly (explained 25.9% of the AHI ^0.5 variability), after adjusting for age, sex, cigarette smoking, alcohol drinking and main comorbidities. In elderly, VA over 128 cm² and VA/SA less than 0.41 resulted in sensitivity, specificity and AUC of 0.382, 0.790, 0.580 and 0.176, 0.947, 0.553 in predicting moderate-to-severe OSA, respectively. In non-elderly, BMI over 24.7 kg/m² and VA/SA over 0.54 resulted in sensitivity, specificity and AUC of 0.883, 0.484, 0.704 and 0.550, 0.710, 0.667 in predicting moderate-to-severe OSA, respectively.ConclusionsVA is strongly associated with OSA severity in elderly, independently of general obesity as per BMI standards, while general adiposity appears to be more strongly associated with OSA severity in non-elderly. Our study supports age-specific approaches should be developed with respect to prediction and treatment of OSA.     

Varenicline administration for smoking cessation may reduce apnea hypopnea index in sleep apnea patients

Objective/Background: Varenicline (VAR) is used for smoking cessation as it inhibits nicotine for binding on its receptors reducing nicotine dependence. VAR administration has been reported to affect sleep. The aim of this study was to evaluate possible changes in polysomnography (PSG) during VAR treatment (SmokeFreeBrain) in healthy smokers and smokers with obstructive sleep apnea (OSA). Patients/Methods: Thirty smokers (21 men) with 15.3 ± 10.2 PY, aged 32.8 ± 4.5 years, with BMI 28.6 ± 4 kg/m², 16 without and 14 with OSA (92% males) were studied with PSG (Embletta MPR-Master) before treatment with VAR while smoking and 20–30 days during VAR administration and smoking cessation for at least 5 days. Results: No significant differences were observed in sleep macro architecture (N1, N2, N3, REM, Sleep Efficiency, Total Sleep Time) during VAR treatment apart from prolongation of sleep latency, N2 and N3 latency in both smokers with and without OSA. Apnea hypopnea index (AHI) was reduced in OSA smokers and especially during REM with a borderline increase of arousal index (ArI) and reduction of sleep efficiency (SE). Conclusion: VAR treatment worsened sleep quality as a prolongation of sleep latency, N2 and N3 latency was observed. A marginal reduction of AHI was found in OSA patients, more significantly during REM. Due to the small sample size, further studies are needed to distinguish between the adverse reactions of VAR treatment and smoking cessation effects and to evaluate whether VAR may play a role in OSA treatment.     

Obstructive sleep apnea,chronic obstructive pulmonary disease and NAFLD: an individual participant data meta-analysis

RationaleChronic intermittent hypoxia occurring in obstructive sleep apnea (OSA) is independently associated with nonalcoholic fatty liver disease (NAFLD). Chronic obstructive pulmonary disease (COPD) has also been suggested to be linked with liver disease.ObjectiveIn this individual participant data meta-analysis, we investigated the association between liver damage and OSA and COPD severity.Methods and measurementsPatients suspected of OSA underwent polysomnography (PSG) or home sleep apnea testing (HSAT). Non-invasive tests were used to evaluate liver steatosis (Hepatic Steatosis Index) and fibrosis (Fibrotest or FibroMeter). An individual participant data meta-analysis approach was used to determine if the severity of OSA/COPD affects the type and severity of liver disease. Results were confirmed by multivariate and causal mediation analysis. Sub-group analyses were performed to investigate specific populations.Main resultsAmong 2120 patients, 1584 had steatosis (75%). In multivariable analysis, risk factors for steatosis were an apnea-hypopnea index (AHI) > 5/h, body mass index (BMI) > 26 kg/m², age, type 2 diabetes (all p-values <0.01) and male gender (p = 0.02). Concerning fibrosis, among 2218 patients 397 had fibrosis (18%). Risk factors associated with fibrosis were BMI>26 kg/m², age, male gender, and type 2 diabetes (all p-values <0.01). AHI severity was not associated with fibrosis. A combination of AHI >30/h and COPD stage 1 was associated with an increased risk of steatosis.ConclusionThis meta-analysis confirms the strong association between steatosis and the severity of OSA. The relation between OSA and fibrosis is mainly due to BMI as shown by causal mediation analysis.     

Prognostic implication of obstructive sleep apnea diagnosed by post-discharge sleep study in patients presenting with acute coronary syndrome

ObjectiveWe aimed to determine the prognostic implications of obstructive sleep apnea (OSA) diagnosed during the recovery phase of acute coronary syndrome (ACS).MethodsPatients presenting with ACS and treated with percutaneous coronary intervention were recruited prospectively for a home-based sleep study within 30 days of hospital discharge. Major adverse cardiac and cerebrovascular events (MACCEs) assessed included cardiac death, myocardial infarction, stroke, unplanned revascularization, and hospitalization for heart failure.ResultsOf the 85 patients recruited, 68 successfully completed the study. The median time from percutaneous coronary intervention to sleep study was 14 days (interquartile range: 7.5–27 days). OSA was diagnosed in 24 patients (35.3%) (apnea–hypopnea index ⩾15). A drug-eluting stent was implanted into the target lesion in 45 patients (66.2%). None of the study patients had received treatment for OSA. At 24-month follow-up, the MACCE incidence was 34.9% in the OSA group and 5.1% in the non-OSA group (P = 0.008, log-rank test). After adjusting for the possible confounding effect of age, gender, coronary intervention indications, hypertension, smoking, and body mass index, OSA remained an independent predictor of MACCEs (adjusted hazard ratio, 6.95; 95% confidence interval, 1.17–41.4; P = 0.033).ConclusionOSA diagnosed in patients treated with percutaneous coronary intervention for ACS by post-discharge sleep studies conducted 2 weeks after percutaneous coronary intervention was independently associated with MACCEs at 24-month follow-up.     

Obstructive sleep apnea is associated with cancer mortality in younger patients

ObjectiveThe association between obstructive sleep apnea (OSA) and cancer mortality has scarcely been studied. The objective of this study was to investigate whether OSA is associated with increased cancer mortality in a large cohort of patients with OSA suspicion.MethodsThis was a multicenter study in consecutive patients investigated for suspected OSA. OSA severity was measured by the apnea–hypopnea index (AHI) and the hypoxemia index (% night-time spent with oxygen saturation <90%, TSat₉₀). The association between OSA severity and cancer mortality was assessed using Cox’s proportional regression analyses after adjusting for relevant confounders.ResultsIn all, 5427 patients with median follow-up of 4.5 years were included. Of these, 527 (9.7%) were diagnosed with cancer. Log-transformed TSat₉₀ was independently associated with increased cancer mortality in the entire cohort (hazard ratio [HR], 1.21; 95% confidence interval [CI], 1.03–1.42), as well as in the group of patients with cancer (HR, 1.19; 95% CI, 1.02–1.41). The closest association was shown in patients <65 years in both the AHI (continuous log-transformed AHI: HR, 1.87; 95% CI, 1.1–3.2; upper vs lower AHI tertile: HR, 3.98; 95% CI, 1.14–3.64) and the TSat₉₀ (continuous log-transformed TSat₉₀: HR, 1.73; 95% CI, 1.23–2.4; upper vs lower TSat₉₀ tertile: HR, 14.4; 95% CI, 1.85–111.6).ConclusionsOSA severity was associated with increased cancer mortality, particularly in patients aged <65 years.     

Obstructive sleep apnea,CPAP therapy and Parkinson's disease motor function: A longitudinal study

IntroductionWe aimed to assess, in patients with Parkinson's disease (PD), the association between obstructive sleep apnea (OSA), progression of motor dysfunction and the effect of OSA treatment.MethodsData were analysed from a prospective cohort study of idiopathic PD patients from a movement disorders clinic. Patients found to have OSA on polysomnography (apnea-hypopnea index [AHI] ≥15 events/h, OSA+) were offered treatment using continuous positive airway pressure (CPAP). CPAP+ was defined as an average ≥ 2 h/night use at each follow-up. Motor symptoms were assessed using the motor section of the Movement Disorder Society Unified Parkinson's Disease Rating Scale (mUPDRS) and the Timed-Up-And-Go (TUG). Follow-up times were 3, 6 and 12 months. Mixed models were constructed, adjusting for age, sex, body mass index, levodopa equivalent dose and comorbidities.ResultsWe studied 67 individuals (61.2% male) of mean age 64.7 years (SD = 10.1). Baseline mUPDRS was higher in OSA+ compared to OSA- (24.5 [13.6] vs. 16.2 [7.2], p < 0.001). Motor dysfunction increased at comparable rates in OSA- and OSA+CPAP-. However, in OSA+CPAP+, mUPDRS change was significantly lower compared to OSA- (β = −0.01 vs. 0.61, p = 0.03; p = 0.12 vs. OSA+CPAP- [β = 0.39]) and TUG change was lower compared to OSA+CPAP- (β = −0.01 vs. 0.13, p = 0.002; p = 0.05 vs. OSA- [β = 0.02]).ConclusionsIn this PD cohort, OSA was associated with higher baseline mUPDRS. In those with OSA, CPAP use was associated with stabilization of motor function (mUPDRS and TUG) over 12 months. These observations support further research to clarify the role of OSA in PD pathophysiology and motor dysfunction.