Clinical Suspicion Of Obstructive Sleep Apnea Research Articles

Comparison of Polysomnography and Cardiopulmonary Coupling in the Diagnosis of Insomnia, Obstructive Sleep Apnoea, or Comorbidity, a Pilot Study

Objective: To verify the reliability of cardiopulmonary coupling (CPC) technology to diagnose chronic insomnia disorder (CID), obstructive sleep apnoea (OSA) and comorbid OSA with insomnia (COI). Methods: Data from 161 patients suffering from the three conditions were collected, and objective sleep status was assessed simultaneously by CPC and polysomnography (PSG). These patients were diagnosed according to the clinical symptoms and PSG results. The general data of the three groups were compared, and the agreement of AHI and sleep parameters between CPC and PSG was analysed by Bland-Altman agreement plots. Results: We found that, when AHI (events/h) ≥ 5, 10, 15, 20, 25 and 30 were used as the conditions for the diagnosis of OSA, the sensitivity was 82.7%, 63.5%, 67.3%, 84.6%, 71.9% and 61.5%; the specificity was 61.6%, 63.3%, 73.4%, 84.4%, 82.9% and 84.4%; and the area under the curve (AUC) was 0.792, 0.735, 0.787, 0.889, 0.884 and 0.861, respectively. Bland-Altman agreement plots for the sleep parameters were measured by PSG and CPC. Although 95% of the points of some graphs were within the consistency range, they were beyond the professionally acceptable threshold range. Conclusion: As a tool for rapid screening of OSA patients, the overall performance of CPC is acceptable in subjects with clinical suspicion of OSA, but the clinical interpretation of sleep parameter results obtained with CPC must be cautious, especially in insomnia state.

Comorbidities and quality of life in Australian men and women with diagnosed and undiagnosed high-risk obstructive sleep apnea.

In a population-based survey, we determined sex differences in health profiles and quality of life between individuals who have a confirmed diagnosis of obstructive sleep apnea (OSA) and those who are at high risk of OSA yet remain undiagnosed. An online survey of Australian adults ≥ 18 years (n = 3,818) identified participants with self-reported diagnosed OSA (n = 460) or high-risk, undiagnosed OSA (OSA50 score ≥ 5, n = 1,015). Ever-diagnosed comorbidities, sociodemographics, and quality of life (EQ-5D-5L, Functional Outcomes of Sleep Questionnaire-10) were assessed. Women were more frequently represented in the high-OSA-risk group compared with those with diagnosed OSA (55.5%, n = 563, versus 43%, n = 198; P < .001). In sex-specific logistic regression analyses, diagnosed OSA was associated with increased likelihoods of ≥ 1 cardiovascular condition (odds ratio: 3.0; 95% confidence interval: 2.0-4.5), hypertension (1.9; 1.3-2.8), gout (1.8; 1.1-2.9), and chronic obstructive pulmonary disease (3.8; 2.1-6.9) in men. In women, an association with asthma (2.0; 1.3-3.0) was seen. Diabetes, arthritis, mental health conditions (ever-diagnosed), and all EQ-5D-5L dimensions were associated with an OSA diagnosis regardless of sex, except for EQ-5D-5L anxiety/depression, which was only associated with an OSA diagnosis in women. A diagnosis of OSA was associated with sleepiness-related impairment (lowest quartile of Functional Outcomes of Sleep Questionnaire-10) in men (1.6; 1.01-2.5) and women (2.2; 1.4-3.6). Sex-specific health conditions may drive diagnosis of OSA; however, clinical suspicion of OSA needs to be increased in men and women. The impaired quality of life and persistent sleepiness in participants with diagnosed OSA observed at a population level requires greater clinical attention. Krishnan S, Chai-Coetzer CL, Grivell N, etal. Comorbidities and quality of life in Australian men and women with diagnosed and undiagnosed high-risk obstructive sleep apnea. J Clin Sleep Med. 2022;18(7):1757-1767.

Nocturnal pulse oximetry as a possible screening method for obstructive sleep apnea in infants with laryngomalacia

ObjectiveLaryngomalacia can be an important cause of obstructive sleep apnea (OSA) in infants. Nocturnal oximetry is a cheap and safe method in comparison to polysomnography for the detection of sleep-disordered breathing. The aim of this study is to evaluate the validity of nocturnal oximetry as a diagnostic tool for OSA in infants with laryngomalacia. MethodsThis retrospective study included infants with laryngomalacia and a clinical suspicion of OSA who underwent a polysomnography at the Antwerp University Hospital. The oximetry was rescored manually, blinded to the polysomnography results, according to four different scoring methods. An obstructive apnea–hypopnea index (oAHI) ≥ 2/h on polysomnography was used to define OSA. ResultsThis study included 53 patients with laryngomalacia (51% boys, mean age 3.72 ± 0.26 months). A diagnosis of OSA was established in 46 patients (87%) by polysomnography. Among the four different scoring methods, the scoring according to Brouillette et al., yielded the highest diagnostic accuracy with a sensitivity and specificity of 91% and 25% respectively and with a negative and positive predictive value of 25% and 91%, respectively. Correlations and the Bland–Altman plot showed a wide limit of agreement for laboratory polysomnography oAHI and nocturnal oximetry ODI. ConclusionOur data show that overnight pulse oximetry has a high sensitivity and PPV to diagnose OSA in infants with laryngomalacia. However, the low specificity and NPV indicate that PSG is still needed to exclude OSA in cases with normal oximetry.

Obstructive Sleep Apnea as a Predictor of Arrhythmias in 24-h ECG Holter Monitoring.

A relationship between obstructive sleep apnea (OSA) and abnormalities in 24-h electrocardiogram (ECG) Holter monitoring has not been sufficiently documented. The aim of this study was to analyze the relation between the occurrence and the severity of OSA and the parameters of ECG Holter monitoring in a group of patients with diagnosed OSA. Ninety-four patients with clinical suspicion of OSA were qualified for the study (mean age 53.7). All participants underwent a medical history, laboratory tests, 24-h ECG Holter monitoring, and single-night video-polysomnography (vPSG) using the American Academy of Sleep Medicine recommendations. A group of patients with diagnosed OSA was characterized by more frequent occurrence of supraventricular tachycardia (SVT) and ventricular arrhythmias (VPC). A statistically significant positive correlation was shown between the apnea-hypopnea index (AHI) and average heart rate, supraventricular arrhythmias (SVPC) pairs, SVT, and pauses >2.5 s. In regression analysis, higher AHI constituted an independent predicator for the increased number of pauses >2.5 s, SVT, and SVPC pairs in 24-h ECG Holter monitoring. In summary, patients with OSA are characterized by the increased number of abnormalities in 24-h ECG Holter monitoring.

A machine learning-based test for adult sleep apnoea screening at home using oximetry and airflow

The most appropriate physiological signals to develop simplified as well as accurate screening tests for obstructive sleep apnoea (OSA) remain unknown. This study aimed at assessing whether joint analysis of at-home oximetry and airflow recordings by means of machine-learning algorithms leads to a significant diagnostic performance increase compared to single-channel approaches. Consecutive patients showing moderate-to-high clinical suspicion of OSA were involved. The apnoea-hypopnoea index (AHI) from unsupervised polysomnography was the gold standard. Oximetry and airflow from at-home polysomnography were parameterised by means of 38 time, frequency, and non-linear variables. Complementarity between both signals was exhaustively inspected via automated feature selection. Regression support vector machines were used to estimate the AHI from single-channel and dual-channel approaches. A total of 239 patients successfully completed at-home polysomnography. The optimum joint model reached 0.93 (95%CI 0.90–0.95) intra-class correlation coefficient between estimated and actual AHI. Overall performance of the dual-channel approach (kappa: 0.71; 4-class accuracy: 81.3%) significantly outperformed individual oximetry (kappa: 0.61; 4-class accuracy: 75.0%) and airflow (kappa: 0.42; 4-class accuracy: 61.5%). According to our findings, oximetry alone was able to reach notably high accuracy, particularly to confirm severe cases of the disease. Nevertheless, oximetry and airflow showed high complementarity leading to a remarkable performance increase compared to single-channel approaches. Consequently, their joint analysis via machine learning enables accurate abbreviated screening of OSA at home.

Obstructive Sleep Apnea as a Predictor of Abnormal Heart Rate Turbulence.

Obstructive sleep apnea (OSA) causes dysfunction of the autonomic nervous system, but the exact mechanism has not been fully understood. The aim of this study was to analyse the relationship between the incidence and severity of OSA and heart rate turbulence (HRT). Seventy one patients with clinical suspicion of OSA were qualified to participate in the study. All participants took part in a survey and were subjected to laboratory tests, 24-hour electrocardiogram (ECG) Holter monitoring with HRT analysis and polysomnography. The group with OSA manifested significantly higher turbulence onset (TO) and lower turbulence slope (TS) as compared to the group without OSA. Older age, diabetes, hypertension and higher apnea/hypopnea index (AHI) were found to be independent risk factors for increased TO, whereas older age, higher body mass index (BMI), higher blood glucose levels, hypertension and higher AHI were independent risk factors for TS reduction. The AHI ≥65 criterion indicates abnormal HRT in patients with OSA with 94.9% sensitivity and 50.0% specificity, which gives a prediction accuracy of 85.7%. In summary, OSA should be considered as a predictor of abnormal HRT.

Validation of a portable monitoring device for the diagnosis of obstructive sleep apnea: electrocardiogram-based cardiopulmonary coupling.

We aimed to evaluate the validity of the cardiopulmonary coupling (CPC) device, a limited-channel portable monitoring device for obstructive sleep apnea (OSA) screening in one single-center cohort, in particular in those with some cardiovascular diseases since the cardiopulmonary coupling might be different from those without. Consecutive patients referred to the sleep medical center for assessment of possible OSA were enrolled in this study. Patients were examined with standard polysomnography (PSG) and CPC evaluation simultaneously. The results of the two examinations were compared in all subjects and in those with or without cardiovascular abnormalities. A total of 179 subjects suspected with OSA were finally analyzed. According to OSA severity degree based on AHI, the area under ROC curve for the CPC device in the whole cohort patients was 0.79 (mild), 0.79 (moderate), and 0.86 (severe OSA), respectively (all p < 0.001). For patients with cardiovascular disease with different OSA severity, the area under the ROC curve was 0.86 (mild), 0.73 (moderate), and 0.83 (severe OSA), respectively (all p < 0.0001), and 0.74 (mild), 0.85 (moderate), and 0.91 (severe OSA), respectively in patients without cardiovascular disease (all p < 0.0001). The overall performance of CPC technique was acceptable to assess OSA in subjects with clinical suspicion of OSA, and thus it might act as a fast tool to screen OSA patients. However, the sensitivity of CPC technology for patients with cardiovascular disease was relatively insufficient. Therefore, CPC technology should be carefully interpreted in OSA screening in those with cardiovascular disease.

Características clínicas de los pacientes con apneas obstructivas del sueño: diferencias según género

Introduction: Obstructive sleep apnea (OSA) is more prevalent in men, population studies show a ratio of 2:1, however in clinical studies the frequency is as high as 6:1. These differences in the clinical setting may be a consequence of variations in the reporting of symptoms in men compared to women. Objective: To evaluate gender differences between women and men with recent diagnosis of OSA. Patients: A cross-sectional, study of patients undergoing home sleep apnea testing (HSAT) with clinical suspicion of OSA. Demographic, anthropometric, comorbidities and HSAT variables were collected. We performed t student analysis, Mann-Whitney test or chi square test as appropriate. Results: 1,044 patients were included: mean age 53.2 ± 14 years, 76% men. Women with OSA have a higher BMI (32.2 ± 6.1 vs 30.8 ± 5.0, p = 0.002), were older (61.4 ± 12.2 vs 52.6 ± 13.9, p <0.001), but have a lower neck circumference (NC) (38.1 ± 3.6 vs. 43.2 ± 3.3, p <0.001). The women presented lower AHI and shorter duration of apneas. Although the classic symptoms of apnea and daytime sleepiness showed no differences, women reported more frequently insomnia, morning headache, depression and use of hypnotic drugs. Conclusions: Clinical differences between gender are present at time of diagnosis. Woman are older and more obese, although they have a lower NC. They have a milder disease, but they refer to be more tired, headache, insomnia and depression. We must be alert in the different clinical presentation of women to improve the diagnostic suspicion.

The use of oximetry and a questionnaire in primary care enables exclusion of a subsequent obstructive sleep apnea diagnosis

PurposeThe study aims to prospectively validate the prognostic value of oximetry alone or combined in a two-step strategy with a questionnaire for the exclusion of obstructive sleep apnea (OSA) in primary care.MethodsA total of 140 subjects with suspected OSA were included from 54 participating primary care practices. All subjects completed the Philips questionnaire and underwent one night of oximetry prior to referral to a sleep center. The prognostic value of two strategies was evaluated against the diagnosis of the sleep center as the gold standard: (1) assume OSA and subsequently refer to a sleep center if the oxygen desaturation index (ODI) is ≥ 5 and (2) assume OSA and refer to a sleep center if the Philips questionnaire score is ≥ 55% (regardless of the ODI) or if the Philips questionnaire score is < 55% and the ODI is ≥ 5.ResultsOSA was diagnosed in the sleep centers in 100 (71%) of the included subjects. Using ODI ≥ 5 alone resulted in a sensitivity of 99.0%, a specificity of 50.0%, a negative predictive value of 95.2%, and a positive predictive value 83.2%. Using the two-step strategy, oximetry would be performed on 39% of the subjects. This strategy resulted in a sensitivity of 100%, a specificity of 35.0%, a negative predictive value of 100%, and a positive predictive value of 79.4%.ConclusionsIn a Dutch primary care population with a clinical suspicion of OSA and low frequency of cardiovascular comorbidities, the use of oximetry alone or combined in a two-step strategy with a questionnaire enables exclusion of a sleep center diagnosis of OSA.

Prothrombotic state in children with obstructive sleep apnea

ObjectiveIncreased blood coagulation might be one important mechanism linking obstructive sleep apnea (OSA) with cardiovascular diseases. We tested the association between several hemostatic parameters and sleep breathing-related variables in a representative pediatric population with a clinical suspicion of OSA. MethodsPolysomnography was performed in 152 snoring children to diagnose OSA. Anthropometric and clinical data were registered and venous blood samples were collected for the measurement of platelet count, plateletcrit, platelet distribution width (PDW), mean platelet volume (MPV), prothrombin time (PT), activated partial thromboplastin time (aPTT), fibrinogen and C-reactive protein. ResultsChildren with OSA had significantly higher platelet count, plateletcrit and PDW compared with those without OSA. After controlling for the anthropometric characteristics (age, gender, body mass index (BMI) z-score), platelet count negatively correlated with minimum SaO2 while the plateletcrit correlated with time with SaO2 <90% and MPV correlated with apnea–hypopnea index. PT and PT international normalized ratio correlated with mean SaO2 and aPTT correlated with the oxygen desaturation index. ConclusionOur findings suggest that different OSA-related effects may be factors contributing to an enhanced coagulability in pediatric OSA. Measures reflecting apnea severity and disrupted sleep were associated with clotting factor changes independent of covariates affecting hemostatic function.

Obstructive sleep apnea as a predictor of reduced heart rate variability

PurposeThis study aimed to analyze the relationship between the occurrence of obstructive sleep apnea (OSA) and heart rate variability (HRV) in a group of patients with clinical suggestion of OSA. Methods104 patients with clinical suspicion of OSA were qualified to participate in the study (age: 53.15 ± 13.43 years). All participants took part in a survey and were subjected to laboratory tests, 24-hour ECG Holter monitoring, and polysomnography. The participants were divided into groups depending on the criterion of the presence of OSA. ResultsThe analysis of time HRV demonstrated lower parameters of SDNN for the entire recording and a 15-minute fragment of daily activity, as well as a lower pNN50 for the entire recording in those patients with diagnosed OSA. A statistically significant difference was observed for the spectral analysis of the LF/HF which was higher in the participants with OSA during the 15-minute fragment of N3 sleep. A negative correlation was observed between AHI and the following parameters: SDSD from the entire Holter recording (r = −0.21, p < 0.05) and from the 15-minute fragment of daily activity (r = −0.19, p < 0.05), mRR from the fragment of N3 sleep (r = −0.19, p < 0.05) and VLF from the entire Holter recording (r = −0.26, p < 0.05). A statistically significant positive correlation between AHI and LF/HF in 15-minute fragments of N3 sleep was found (r = 0.26, p < 0.05). ConclusionsThe study group of patients with OSA is characterized by reduced HRV. The higher AHI constitutes an independent predictor of reduced HRV, both in the sympathetic and parasympathetic components, and the sympathetic-parasympathetic balance.

A Prognosis Tool Based on Fuzzy Anthropometric and Questionnaire Data for Obstructive Sleep Apnea Severity.

Obstructive sleep apnea (OSA) are linked to the augmented risk of morbidity and mortality. Although polysomnography is considered a well-established method for diagnosing OSA, it suffers the weakness of time consuming and labor intensive, and requires doctors and attending personnel to conduct an overnight evaluation in sleep laboratories with dedicated systems. This study aims at proposing an efficient diagnosis approach for OSA on the basis of anthropometric and questionnaire data. The proposed approach integrates fuzzy set theory and decision tree to predict OSA patterns. A total of 3343 subjects who were referred for clinical suspicion of OSA (eventually 2869 confirmed with OSA and 474 otherwise) were collected, and then classified by the degree of severity. According to an assessment of experiment results on g-means, our proposed method outperforms other methods such as linear regression, decision tree, back propagation neural network, support vector machine, and learning vector quantization. The proposed method is highly viable and capable of detecting the severity of OSA. It can assist doctors in pre-diagnosis of OSA before running the formal PSG test, thereby enabling the more effective use of medical resources.

The association of neutrophil to lymphocyte ratio with presence and severity of obstructive sleep apnea.

Obstructive sleep apnea (OSA) is characterized by reductions in breathing amplitude during sleep caused by an obstructed or collapsed upper airway. The neutrophil to lymphocyte ratio (NLR) has been proposed as a novel biomarker for systemic inflammatory response. The aim of the present study was to evaluate the relationship between NLR and OSA. The study population consisted of 195 consecutive patients with clinical suspicion of OSA. Full night polysomnography was performed for all patients. Patients with an apnea hypopnea index (AHI) ≥ 5 were considered to have OSA. NLR was calculated as the ratio of neutrophil count to lymphocyte count. While 130 patients (91 male, mean age: 49.9±9.8 years) had OSA, 65 patients (42 male, mean age: 48.7 ± 10.2 years) had normal findings according to AHI scores. Cardiovascular risk factors such as hypertension, hyperlipidemia, diabetes mellitus and smoking were more common in patients with OSA. Patients with OSA had significantly higher NLR than controls (1.87±0.80 vs 1.49±0.48, p=0.005). AHI score was significantly correlated with NLR (r=0.228, p=0.001). NLR and presence of hyperlipidemia were independent predictors of OSA (OR: 2.451, 2.850, p=0.001, 0.004, respectively). NLR of 1.62 or higher predicted OSA with a sensitivity of 56.2 % and specificity of 63.1 %. NLR was higher and also correlated with AHI score in patients with OSA which has not been reported previously. NLR more than 1.62 was an independent predictor of OSA. A simple, cheap white blood cell count may also give an idea about the presence and severity of OSA (Tab. 3, Fig. 3, Ref. 30).

Clinical Characteristics are Not Significant Predictors of Advanced Obstructive Sleep Apnea in the Severely Obese

Introduction: Obstructive Sleep Apnea (OSA), present in 30-93% of bariatric patients, is an independent predictor of post-bariatric surgery complications. Universal screening with Polysomnography (PSG), the gold standard test for OSA, would be difficult to access and costly to perform. The purpose of this study was to identify clinically important, statistically significant predictors of moderate-to-severe OSA in a bariatric population that would enable providers to stratify or prioritize patients needing PSG. Methods: A cross-sectional study was performed in patients referred for clinical suspicion of OSA. All patients underwent PSG. From a list of potential covariates deemed clinically important, multivariable binary logistic regression was used to identify statistically significant predictors (p<0.05) of moderate-to-severe OSA. Subjects were recruited from a bariatric specialty program in Edmonton, Alberta, with a central, region-wide, single-point-ofaccess referral system. Results: Of 169 patients undergoing PSG, 161 (95.3%) had complete data. Mean age was 48.7 ± 9.1 years, 45(28%) were men, mean body mass index (BMI) was 49.5 ± 9.7 kg/m2. 96(60%) patients had moderate-to-severe OSA and the mean Apnea-Hypopnea Index (AHI) was 27.0 ± 27.3. The strongest predictors of OSA were neck circumference (OR 1.08; 95% CI 0.99-1.18) and hypertension (OR 1.95, 95% CI 0.93-4.09). However, no variable reached statistical significance. Conclusion: Despite a model adequately powered to identify 16-32 statistically significant predictors, none was found. Given the high prevalence of OSA in patients undergoing bariatric care, the lack of identifiable predictors mandates that objective sleep testing be performed in all patients clinically suspected to have OSA.

Validation of two depression screening instruments in a sleep disorders clinic.

Depression is a commonly diagnosed comorbidity in sleep disorder clinics. However, screening instruments for major depressive episode (MDE) have not been validated in this setting. We aimed to validate the Hospital Anxiety and Depression Scale (HADS) and the Beck Depression Inventory - Fast Screen (BDI-FS) with the Mini International Neuropsychiatric Interview (MINI) in patients with suspected obstructive sleep apnea (OSA). Cross-sectional study. Academic center. One hundred one new patients with a clinical suspicion of OSA, as assessed by a sleep physician. MDE, generalized anxiety disorder (GAD), and panic disorder (PD) were assessed by (1) a diagnostic interview utilizing the MINI and (2) by two self-report questionnaires: HADS and BDI-FS. A receiver operating characteristic (ROC) analysis was undertaken to assess which HADS and BDI-FS threshold yielded the highest correlation for a diagnosis of MDE and/or GAD/PD as assessed with an interview conducted using the MINI. A HADS-Depression score ≥ 8 gave optimal sensitivity (83.1%) and specificity (83.3%) with an area under the ROC curve (AUC) 0.851 for predicting the diagnosis of MDE. A HADS-Anxiety score ≥ 11 gave an optimal sensitivity (93.1%) and specificity (84.7%) with an AUC 0.911 for predicting the diagnosis of GAD/PD. A BDI-FS threshold ≥ 6 gave optimal sensitivity (86.7%) and specificity (82.9%) with an AUC 0.897 for MDE. The HADS and BDI-FS are accurate screening instruments with high concurrent validity for identifying the probability of a patient having MDE and-in the case of HADS-GAD and PD disorder in a sleep disorders clinic.

Good as ‘Gold’? Portable Sleep Study Devices for Sleep-Disordered Breathing in Children

Good as ‘Gold’? Portable Sleep Study Devices for Sleep-Disordered Breathing in Children

Insulin resistance in obstructive sleep apnea

OSA is a common condition that is primarily characterized by intermittent and recurrent pauses in respiration results in multiple cycles of hypoxia/reoxygenation with an increased production of reactive oxygen species (ROS). Aim of work: Is to assess serum insulin level &insulin resistance in obese patients with & without OSA. Study was performed on 51 obese subjects who had been referred to Chest Department of Kasr Alaini Hospital with clinical suspicion of OSA in order to perform Polysomnography. They were classified into two groups; Cases: consists of 33 obese patients who were diagnosed as obstructive sleep apnea (OSA) & Controls: consists of 18 obese subjects, without OSA as a control group. The two groups were subjected to Full history taking, Clinical examination, Epworth sleepiness scale (ESS), Anthrop-ometric measurements including body mass index (BMI in kg/m2) waist, hip circumferences, waist/hip ratio and neck circumference, Polysomno-graphic study, Serum Insulin by ELISA & Assessment of insulin resistance by calculation of HOMA index. It was found that cases included 10 females (30.3%) & 23 males (69.7%), while controls included 14 females (77.8%) & 4 (22.2%).There was statistically highly significant increase in Epworth slee-piness scale (ESS) among cases compared to controls. As regards the Polysonographic data, there was statistically highly significant increase in AHI, desaturation index & duration of desaturation <90%. among cases compared to control subjects. Regarding minimal O2 sat% & average O2 sat% were lower in cases than in the control subjects and this reduction was statistically significant also there was statistically significant increase in arrhythmias index among cases than control subjects & there was significant increase in snoring index among cases than control subjects. There was statistically highly significant increase in serum insulin, HOMA index among cases as compared to controls. Insulin resistance in OSA is related to sleep associated hypoxaemia & hypoxic stress. Chest Department, Faculty of Medicine Cai-ro University.

Obstructive sleep apnea and metabolic syndrome in spanish population.

Obstructive sleep apnea (OSA) is a clinical picture characterized by repeated episodes of obstruction of the upper airway. OSA is associated with cardiovascular risk factors, some of which are components of metabolic syndrome (MS).Objectives:First, determine the prevalence of MS in patients with OSA visited in sleep clinic. Second, evaluate whether there is an independent association between MS components and the severity of OSA.Methods:Patients with clinical suspicion of OSA were evaluated by polysomnography. Three groups were defined according to apnea hypoapnea index (AHI): no OSA (AHI <5), mild-moderate (AHI≥ 5 ≤30), and severe (AHI> 30). All patients were determined in fasting blood glucose, total cholesterol, HDL cholesterol, triglycerides and insulin. MS was defined according to criteria of National Cholesterol Education Program (NCEP).Results:A total of 141 patients (mean age 54 ± 11 years) were evaluated. According to AIH, 25 subjects had no OSA and 116 had OSA (41mild-moderate and 75 severe). MS prevalence ranged from 43-81% in OSA group. Also, a significant increase in waist circumference, triglycerides, glucose, blood pressure levels, and a decrease in HDL cholesterol levels was observed in more severe OSA patients. All polysomnographic parameters correlated significantly with metabolic abnormalities. After a multiple regression analysis, abdominal obesity (p <0.02), glucose (p <0.01) and HDL cholesterol (p <0.001) were independently associated with OSA.Conclusions:Our findings show high prevalence of MS in OSA, especially in severe group. A significant association between OSA and some of the components of MS was found in Spanish population.

CPAP does not reduce high-sensitivity c-reactive protein in patients with coronary artery disease and obstructive sleep apnea

Obstructive sleep apnea (OSA) is associated with an increase in high-sensitivity C-reactive protein (hs-CRP). Studies suggested that the degree of severity of OSA in obese patients with no known coronary artery disease correlates with higher levels of hs-CRP and that continuous positive airway pressure (CPAP) could reduce this inflammation marker. In this study we tested the hypothesis that CPAP therapy could also reduce hs-CRP in cardiac patients with multiple comorbidities and known OSA. Sixty-two consecutive patients were included in this study. All patients were referred for a sleep test because of clinical suspicion of OSA. Clinical variables, body mass index (BMI), hs-CRP, and lipid profile were obtained at the time of their referral and at 126.2 ± 33.7 days followup. Thirty-four patients (group A) underwent CPAP therapy and 28 patients did not (group B). The linear regression of hs-CRP level on the severity of the apnea–hypopnea index (AHI) was significant (p = 0.05), but this significance is lost when ln(hs-CRP) was used (p = 0.263). Through analysis of covariance, ln(hs-CRP) was predicted by BMI (p = 0.000) (R-Sq = 46.2%). In group A, and despite a significant drop in the AHI with CPAP [median difference = −29.7 (−41.8, −22.2)], there were no significant differences in patients’ BMI, lipid profile, or hs-CRP [median difference = −0.15 (−0.83, 0.64)] (p = 0.53) on followup. When both groups A and B were compared, they had matched BMI, lipids, ejection fraction, blood pressure, age, creatinine, awake O2 saturations, alcohol consumption, coronary artery disease, and baseline and followup hs-CRP despite significant differences in baseline AHI (37.65 vs 14.30, respectively, p = 0.000). We conclude that the degree of OSA or CPAP treatment does not independently predict levels of ln(hs-CRP) in cardiac outpatients when other clinical variables, BMI, and lipids are adjusted for. BMI remains the strongest independent predictor of hs-CRP in this patient population.

The relationship between high-sensitivity C-reactive protein levels and the severity of obstructive sleep apnea

There is an increased risk of cardiovascular and cerebrovascular events in patients with obstructive sleep apnea (OSA). High-sensitivity C-reactive protein (hs-CRP) is a marker that predicts atherosclerotic complications. However, there are contradictory results about the correlation between serum hs-CRP levels and OSA severity. The purpose of this work was to evaluate the relationship between hs-CRP levels and the severity of OSA in newly diagnosed OSA patients. The study group was composed of 76 patients with clinical suspicion of OSA. Subjects with body mass indexes (BMI) ≥30 kg/m(2) were classified as obese. Full-night polysomnography (PSG) was performed on all patients. Patients with an apnea-hypopnea index (AHI) ≥5 were considered to have OSA, and patients with an AHI <5 were accepted as the control group. Blood samples were taken from all patients to analyze serum hs-CRP levels the morning after PSG. The serum hs-CRP levels were significantly higher in the OSA group (4.03 ± 3.58 mg/L) than in the control group (2.41 ± 1.95 mg/L) (p = 0.013). This high level was positively correlated with BMI (r = 0.376, p = 0.001) and with AHI (r = 0.280, p = 0.014). In multiple regression analysis, elevated hs-CRP levels were associated with AHI (F = 3.293, p = 0.033), which was independent of obesity. Patients with OSA have elevated serum levels of hs-CRP, a marker for inflammation and an independent risk predictor for cardiovascular morbidity. The severity of OSA is responsible for the elevation of hs-CRP.