Chaido Pastaka

Reactive oxygen metabolites (ROMs) as an index of oxidative stress in Obstructive sleep apnea patients

Study Objectives: Obstructive sleep apnea syndrome (OSA) is accompanied by oxygen desaturation and arousal from sleep. Free oxygen radicals are highly reactive molecules which could be produced by the OSA phenomenon of hypoxia/reoxygenation: cyclical alterations of arterial oxygen saturation with oxygen desaturation developing in response to apneas followed by resumption of oxygen saturation during hyperventilation. On the basis of these considerations, it was hypothesized that OSA may be linked to increased oxidative stress. Materials and methods: Twenty-six participants gave an interview during which a physician asked them about their age, smoking habits, and symptoms such as excessive daytime sleepiness and snoring. Physical examination and polysomnography were performed during their hospitalization. Reactive oxygen metabolites (ROMs) were measured in blood samples by the diacron reactive oxygen metabolites (D-ROM) test. Results: Twenty-one out of 26 subjects had an apnea/hypopnea index greater than 5 (OSA group). The measurement of free radicals was high in OSA patients. Furthermore, ROMs values in OSA patients were linearly correlated with the apnea/hypopnea index (R = 0.426; p = 0.042). The predictive value of a positive D-ROM test is 81%. Conclusions: ROMs were elevated in patients with OSA. When OSA was severe, similarly the value of ROMs in blood samples was enhanced, and the probable underlying mechanism for these events is the hypoxia/reoxygenation phenomenon.

One-year non-invasive ventilation in chronic hypercapnic COPD: Effect on quality of life

The data on long-term application of non-invasive ventilation (NIV) in patients with chronic respiratory failure due to COPD are contradictory. We evaluated the effect of the addition of NIV to optimal treatment for 1 year on the quality of life of stable hypercapnic COPD patients. NIV was offered to 49 of 58 initially enrolled consecutive patients, of whom 22 refused NIV and comprised the standard treatment group whereas 27 received NIV. Quality of life was assessed with the SF-36 questionnaire. Additional measurements included blood gases, pulmonary function tests, dyspnea, daytime sleepiness, exacerbations and hospitalizations. The NIV group showed a significant improvement in quality of life in the third month, both in the Physical (31+/-4 to 38+/-8, p<0.0001) and the Mental Component Summary Score (28+/-7 to 40+/-10, p=0.009), that was maintained until the twelfth month. PaCO2 decreased by the first month in the NIV group (54+/-4.5 to 44.6+/-5.6 mmHg, p<0.0001), and PaO2 rose during the sixth month (58.9+/-5.7 to 64.4+/-6.5 mmHg, p=0.004). Dyspnea and diurnal sleepiness improved significantly. No significant improvements were observed in the control group. Patients on NIV spent less days in the hospital compared to controls. NIV when added to optimal medical treatment has beneficial effects on quality of life in stable hypercapnic COPD patients, with additional improvements in arterial blood gases, dyspnea and daytime sleepiness.

Noninvasive Ventilation in Chronic Respiratory Failure: Effects on Quality of Life

Background: Noninvasive ventilation (NIV) has been found to be an essential technique to treat chronic respiratory failure (CRF) resulting from restrictive thoracic disorders (RTD). The last decades were characterized by the expansion of NIV to treat patients suffering from various other conditions, such as chronic obstructive pulmonary disease (COPD) and obesity hypoventilation syndrome (OHS). Objectives: The aim of this study was to evaluate the effect of NIV on health-related quality of life (HRQoL) of patients with CRF during 2 years and to identify parameters associated with changes in HRQoL. Methods: Ninety-one patients with CRF [35 COPD; 17 RTD; 28 OHS; 11 neuromuscular diseases (NMD)] participated. HRQoL was assessed with the SF-36 questionnaire. Additional measurements included blood gases, pulmonary function tests, dyspnea, daytime sleepiness, exacerbations and hospitalizations. The patients were evaluated every 3–6 months. Results: Improvements in SF-36 physical component summary (PCS, p < 0.0001) and mental component summary (MCS, p < 0.0001) scores in RTD and MCS in OHS (p = 0.01) and COPD (p = 0.003) were observed by the third month. PCS in OHS and COPD patients improved by the sixth month (p = 0.003 and p < 0.0001, respectively). NMD patients did not present improvements in HRQoL. Improvements in HRQoL were associated with improvements in PaO2 and dyspnea in COPD patients, and with total hours of daily ventilator use, improvement in dyspnea, pressure support and expiratory positive airway pressure in RTD patients. Conclusion: Home NIV is consistently effective in improving HRQoL and physiological parameters in patients with CRF. Randomized trials to identify subgroups of COPD responders are justified by our results.

Phenotypes of comorbidity in OSAS patients: combining categorical principal component analysis with cluster analysis

Phenotyping obstructive sleep apnea syndromes comorbidity has been attempted for the first time only recently. The aim of our study was to determine phenotypes of comorbidity in obstructive sleep apnea syndrome patients employing a data‐driven approach. Data from 1472 consecutive patient records were recovered from our hospitals database. Categorical principal component analysis and two‐step clustering were employed to detect distinct clusters in the data. Univariate comparisons between clusters included one‐way analysis of variance with Bonferroni correction and chi‐square tests. Predictors of pairwise cluster membership were determined via a binary logistic regression model. The analyses revealed six distinct clusters: A, ‘healthy, reporting sleeping related symptoms’; B, ‘mild obstructive sleep apnea syndrome without significant comorbidities’; C1: ‘moderate obstructive sleep apnea syndrome, obesity, without significant comorbidities’; C2: ‘moderate obstructive sleep apnea syndrome with severe comorbidity, obesity and the exclusive inclusion of stroke’; D1: ‘severe obstructive sleep apnea syndrome and obesity without comorbidity and a 33.8% prevalence of hypertension’; and D2: ‘severe obstructive sleep apnea syndrome with severe comorbidities, along with the highest Epworth Sleepiness Scale score and highest body mass index’. Clusters differed significantly in apnea–hypopnea index, oxygen desaturation index; arousal index; age, body mass index, minimum oxygen saturation and daytime oxygen saturation (one‐way analysis of variance P < 0.0001). Binary logistic regression indicated that older age, greater body mass index, lower daytime oxygen saturation and hypertension were associated independently with an increased risk of belonging in a comorbid cluster. Six distinct phenotypes of obstructive sleep apnea syndrome and its comorbidities were identified. Mapping the heterogeneity of the obstructive sleep apnea syndrome may help the early identification of at‐risk groups. Finally, determining predictors of comorbidity for the moderate and severe strata of these phenotypes implies a need to take these factors into account when considering obstructive sleep apnea syndrome treatment options.

The Floppy Eyelid Syndrome: Evaluating Lid Laxity and Its Correlation to Sleep Apnea Syndrome and Body Mass Index

Background. The aim of this study is to present a method of lid laxity evaluation and investigate whether there is an association between floppy eyelid syndrome (FES) and body mass index (BMI) in sleep apnea syndrome (SAS) patients compared to normal subjects. Method. A total of 135 participants (81 patients with SAS and 54 normal subjects) had a full ophthalmologic examination. The presence of FES was estimated in relation to SAS and BMI. Results. The floppy eyelid was characterized “hyperelastic,” “FES stage 1 (asymptomatic),” or “FES stage 2 (symptomatic)” depending on its laxity capacity. Hyperelastic floppy eyelid in SAS patients was statistically significant (P < 0.05) when compared to normals. Similarly, the presence of hyperelasticity in high-BMI SAS patients was also statistically significant (P < 0.05) when compared to low-BMI SAS patients. Floppy eyelid syndrome was more frequent in SAS patients than in normal subjects (P < 0.05), but no association was found between FES and obesity (P > 0.05). Conclusion. A classification of FES is proposed based on lid laxity. In addition to this, our data suggests a clear association of hyperelasticity and FES to SAS patients but no association between obesity and FES.

Sleep apnoea syndrome and early stage cirrhosis: a pilot study.

Objectives Hepatic encephalopathy in patients with end-stage liver cirrhosis is associated with alterations in sleep patterns. Cirrhosis may also affect pulmonary function and it might be involved in the development of obstructive sleep apnoea syndrome (OSAS) in patients with ascites. We carried out a study to evaluate the presence of OSAS in cirrhotic patients without evidence of ascites (early stage cirrhosis). Methods We investigated 20 patients with Child A or B cirrhosis (19 and one, respectively) and 10 non-cirrhotic patients with chronic viral hepatitis (disease control group). All subjects were interviewed and underwent a thorough physical examination, a full polysomnographic study and a pulmonary function testing by spirometry. Serum samples were also obtained in order to determine the liver function tests. Results The presence of OSAS and inverted sleep patterns was similar in cirrhotic patients and disease controls. However, significant correlations were revealed between age and hypopnoeas per hour of sleep; age and the Apneas/Hypopneas Index (AHI); age and FEV1/FVC; gamma-glutamyl transpeptidase and FEV1/FVC; and total bilirubin and total sleep time. Conclusions Early stage cirrhosis is not associated with sleep disorders and OSAS. However, total bilirubin levels might be a useful laboratory marker for early assessment of disturbance in sleep patterns and therefore of subclinical hepatic encephalopathy in Child A cirrhosis.

Age, Body Mass Index, and Daytime and Nocturnal Hypoxia as Predictors of Hypertension in Patients With Obstructive Sleep Apnea

A growing body of evidence links obstructive sleep apnea (OSA) with hypertension. The authors performed a retrospective cohort study using the University Hospital of Larissa Sleep Apnea Database (1501 patients) to determine predictors of in‐laboratory diagnosed OSA for development of hypertension. Differences in continuous variables were assessed via independent samples t test, whereas discrete variables were compared by Pearsons chi‐square test. Multivariate analysis was performed via discriminant function analysis. There were several significant differences between hypertensive and normotensive patients. Age, body mass index, comorbidity, daytime oxygen saturation, and indices of hypoxia during sleep were deemed the most accurate predictors of hypertension, whereas apnea‐hypopnea index and desaturation index were not. The single derived discriminant function was statistically significant (Wilks lambda=0.771, χ2=289.070, P<.0001). Daytime and nocturnal hypoxia as consequences of chronic intermittent hypoxia play a central role in OSA‐related hypertension and should be further evaluated as possible severity markers in OSA.

Hypercapnic COPD patients and NIV at home: is there any benefit? Using the CAT and BODE index in an effort to prove benefits of NIV in these patients

Introduction The benefits of long-term noninvasive ventilation (NIV) in stable COPD with chronic hypercapnic respiratory failure (CHRF) have been debated for many years due to the conflicting results observed in these patients. Materials and methods We investigated the effects of domiciliary NIV in stable hypercapnic COPD patients for a period of 1 year using COPD Assessment Test (CAT), BODE Index, and the number of acute exacerbations. NIV was administered in 57 stable COPD patients with CHRF in the spontaneous/timed mode. Spirometry, 6 minute walk test, Medical Research Council dyspnea scale, arterial blood gases, number of acute exacerbations, BODE Index, and CAT were assessed. Study participants were reassessed in the 1st, 6th, and 12th months after the initial evaluation. Results There was a significant improvement in COPD exacerbations (p<0.001), CAT (p<0.001), PO2 (p<0.001), PCO2 (p<0.001), and Medical Research Council dyspnea scale (p<0.001) in 1 year of follow-up. BODE Index was improved in the first 6 months (5.8±2.2 vs 4.8±2.4, p<0.001), but the improvement was not maintained. Conclusion In conclusion, domiciliary NIV in stable COPD patients with CHRF has beneficial effect on CAT, arterial blood gases, and number of acute exacerbations in a year of NIV use at home. A significant improvement in BODE Index from baseline to 12 months was found in patients aged >70 years, while for those aged <70, the improvement was not maintained after the sixth month.

Non-Invasive Ventilation (NIV) and Homeostatic Model Assessment (HOMA) Index in Stable Chronic Obstructive Pulmonary Disease (COPD) Patients with Chronic Hypercapnic Respiratory Failure: A Pilot Study

Abstract The effects of Non-invasive Ventilation (NIV) on Insulin Resistance (IR) in stable Chronic Obstructive Pulmonary Disease (COPD) patients have not been fully explored. The aim of this study was to assess the effects of NIV on IR and adiponectin levels during one year application of NIV in stable COPD patients with Chronic Hypercapnic Respiratory Failure. Twenty-five (25) stable COPD patients with Chronic Hypercapnic Respiratory Failure and with no self-reported comorbidities completed the study. NIV was administered in the spontaneous/timed mode via a full face mask using a bi-level positive airway pressure system. Spirometry, blood pressure, arterial blood gases, dyspnea, daytime sleepiness, serum fasting glucose and insulin levels were assessed. IR was assessed with the calculation of the Homeostatic Model Assessment (HOMA) index. Adiponectin was measured with radioimmunoassay. Study participants were re-evaluated on the first, third, sixth, ninth and twelfth month after the initial evaluation. There was a significant improvement in FEV1 values from the first month (34.1 ± 11.6% vs 37 ± 12.3%, p = 0.05). There was a significant decrease in IR by the ninth month of NIV use (3.4 ± 2.3 vs 2.2 ± 1.4, p < 0.0001), while adiponectin levels significantly improved from the first month of NIV use. Stepwise regression analysis revealed that baseline HOMA index was associated with paCO2 (⇓ = 0.07 ± 0.02, p = 0.001), while baseline adiponectin levels were associated with FVC (⇓ = 0.05 ± 0.02, p = 0.035) and the concentration of serum bicarbonate (HCO3-) (-⇓ = 0.18 ± 0.06, p = 0.002). Insulin sensitivity and glucose metabolism as well as adiponectin levels improved along with the improvements in respiratory failure.