Olga Mediano

Obstructive Sleep Apnea Syndrome Affects Left Ventricular Diastolic Function Effects of Nasal Continuous Positive Airway Pressure in Men

Background—The purpose of this study was to determine the role of obstructive sleep apnea syndrome (OSAS) as an independent risk factor for the development of left ventricular diastolic abnormalities. Moreover, we tested the hypothesis that nasal continuous positive airway pressure (nCPAP) improves such alterations in OSAS patients by eliminating apneic events. Methods and Results—In this prospective, randomized, placebo-controlled, double-blind crossover study, 27 consecutive newly diagnosed middle-aged OSAS men with neither controllable factors nor conditions affecting left ventricular diastolic function and 15 healthy control subjects were selected. OSAS patients were randomized to 12 weeks on sham nCPAP and 12 weeks on effective nCPAP application. Echocardiographic parameters, blood pressure recordings, and urinary catecholamine levels were obtained at baseline and after both treatment modalities. At baseline, an abnormal left ventricular filling pattern was present in 15 of the 27 OSAS patients and only in 3 of the 15 control subjects (P=0.020). Impaired relaxation was by far the most common abnormal pattern in both groups (11 and 3 patients, respectively). In OSAS patients, 12 weeks on effective nCPAP induced a significant increase in E/A ratio (P<0.01), as well as reductions in mitral deceleration (P<0.01) and isovolumic relaxation (P<0.05) times. Conclusions—OSAS can affect left ventricular diastolic function independently of other possible factors. Chronic application of nCPAP could avoid the progression of diastolic abnormalities, and indeed, it might reverse these alterations, at least in the initial stages before severe structural changes can be developed.

CPAP for Prevention of Cardiovascular Events in Obstructive Sleep Apnea

BACKGROUND Obstructive sleep apnea is associated with an increased risk of cardiovascular events; whether treatment with continuous positive airway pressure (CPAP) prevents major cardiovascular events is uncertain. METHODS After a 1-week run-in period during which the participants used sham CPAP, we randomly assigned 2717 eligible adults between 45 and 75 years of age who had moderate-to-severe obstructive sleep apnea and coronary or cerebrovascular disease to receive CPAP treatment plus usual care (CPAP group) or usual care alone (usual-care group). The primary composite end point was death from cardiovascular causes, myocardial infarction, stroke, or hospitalization for unstable angina, heart failure, or transient ischemic attack. Secondary end points included other cardiovascular outcomes, health-related quality of life, snoring symptoms, daytime sleepiness, and mood. RESULTS Most of the participants were men who had moderate-to-severe obstructive sleep apnea and minimal sleepiness. In the CPAP group, the mean duration of adherence to CPAP therapy was 3.3 hours per night, and the mean apnea-hypopnea index (the number of apnea or hypopnea events per hour of recording) decreased from 29.0 events per hour at baseline to 3.7 events per hour during follow-up. After a mean follow-up of 3.7 years, a primary end-point event had occurred in 229 participants in the CPAP group (17.0%) and in 207 participants in the usual-care group (15.4%) (hazard ratio with CPAP, 1.10; 95% confidence interval, 0.91 to 1.32; P=0.34). No significant effect on any individual or other composite cardiovascular end point was observed. CPAP significantly reduced snoring and daytime sleepiness and improved health-related quality of life and mood. CONCLUSIONS Therapy with CPAP plus usual care, as compared with usual care alone, did not prevent cardiovascular events in patients with moderate-to-severe obstructive sleep apnea and established cardiovascular disease. (Funded by the National Health and Medical Research Council of Australia and others; SAVE ClinicalTrials.gov number, NCT00738179 ; Australian New Zealand Clinical Trials Registry number, ACTRN12608000409370 .).

Daily physical activity in patients with chronic obstructive pulmonary disease is mainly associated with dynamic hyperinflation.

RATIONALE Although the major limitation to exercise performance in patients with COPD is dynamic hyperinflation, little is known about its relation to daily physical activity. OBJECTIVES To analyze the contribution of dynamic hyperinflation, exercise tolerance, and airway oxidative stress to physical activity in patients with COPD. METHODS In a cross-sectional study, we included 110 patients with moderate to very severe COPD. Daily physical activity was measured using a triaxial accelerometer providing a mean of 1-minute movement epochs as vector magnitude units (VMU). Patients performed the 6-minute walk test, incremental exercise test with measurement of breathing pattern and operating lung volumes, and constant-work rate test at 75% of maximal work rate. MEASUREMENTS AND MAIN RESULTS Using the GOLD stage and BODE index, we determined arterial blood gases, lung volumes, diffusing capacity, and biomarkers in exhaled breath condensate. Daily physical activity was lower in the 89 patients who developed dynamic hyperinflation than in the 21 who did not (n =161 [SD 70] vs. n = 288 [SD 85] VMU; P = 0.001). Physical activity was mainly related to distance walked in 6 minutes (r = 0.72; P = 0.001), Vo(2) (r = 0.63; P = 0.001), change in end-expiratory lung volume during exercise (r = -0.73; P = 0.001), endurance time (r = 0.61; P = 0.001), and 8-isoprostane in exhaled breath condensate (r = -0.67; P = 0.001). In a multivariate linear regression analysis using VMU as a dependent variable, dynamic hyperinflation, change in end-expiratory lung volume, and distance walked in 6 minutes were retained in the prediction model (r(2) = 0.84; P = 0.001). CONCLUSIONS Daily physical activity of patients with COPD is mainly associated with dynamic hyperinflation, regardless of severity classification.

Daytime sleepiness and polysomnographic variables in sleep apnoea patients

Excessive daytime sleepiness (EDS) is not invariably present in patients with obstructive sleep apnoea syndrome (OSAS). The aim of the present study was to investigate polysomnographic determinants of EDS in patients with OSAS. EDS was assessed using the Epworth Sleepiness Scale (ESS) and the multiple sleep latency test (MSLT). Patients showed EDS whenever the ESS score was >10 and the MSLT score <5 min. Absence of EDS was defined as having an ESS score of <10 and an MSLT score of >10 min. In total, 23 male patients with EDS (mean±sd ESS and MSLT score 17±3 and 4±1 min, respectively) and 17 without EDS (ESS and MSLT score 5±2 and 16±3 min, respectively), were studied. Both groups exhibited a similar apnoea/hypopnoea index (62±18 versus 60±20 events·h−1). Patients with EDS exhibited shorter sleep latency (11±16 versus 18±18 min) and greater sleep efficiency (90±7 versus 82±13%) than those without EDS. Patients with EDS showed lower oxygenation (lowest arterial oxygen saturation 69±12 versus 79±8%; mean arterial oxygen saturation 87±6 versus 90±5%). Sleep stage distribution and arousal index did not differ between the groups. Patients with obstructive sleep apnoea syndrome and excessive daytime sleepiness are characterised by shorter sleep latency, increased sleep efficiency and worse nocturnal oxygenation than those without excessive daytime sleepiness. Nocturnal hypoxaemia can be a major determinant of excessive daytime sleepiness in patients with obstructive sleep apnoea syndrome.

Daytime sleepiness and polysomnography in obstructive sleep apnea patients

BACKGROUND Excessive daytime sleepiness (EDS) is the major complaint in subjects with obstructive sleep apnea syndrome (OSAS). However, EDS is not universally present in all patients with OSAS. The mechanisms explaining why some patients with OSAS complain of EDS whereas others do not are unknown. OBJECTIVE To investigate polysomnographic determinants of excessive daytime sleepiness (EDS) in a large multicenter cohort of patients with obstructive sleep apnea (OSAS). METHODS All consecutive patients with an apnea-hypopnea index greater than 5h(-1) who were evaluated between 2003 and 2005. EDS was assessed using the Epworth Sleepiness Scale (ESS), and patients were considered to have EDS if the ESS was >10. RESULTS A total of 1649 patients with EDS ((mean [+/-SD] Epworth 15+/-3) and 1233 without EDS (Epworth 7+/-3) were studied. Patients with EDS were slightly younger than patients without EDS (51+/-12 vs 54+/-13 years, p<0.0001), had longer total sleep time (p<0.007), shorter sleep latency (p<0001), greater sleep efficiency (p<0.0001) and less NREM sleep in stages 1 and 2 (p<0.007) than those without EDS. Furthermore, patients with EDS had slightly higher AHI (p<0.005) and arousal index (p<0.001) and lower nadir oxygen saturation (p<0.01). CONCLUSIONS Patients with OSAS and EDS are characterized by longer sleep duration and increased slow wave sleep compared to those without EDS. Although patients with EDS showed a mild worsening of respiratory disturbance and sleep fragmentation, these results suggest that sleep apnea and sleep disruption are not the primary determinants of EDS in all of these patients.

CPAP effect on recurrent episodes in patients with sleep apnea and myocardial infarction

BACKGROUND Obstructive sleep apnea (OSA) is linked to increased cardiovascular risk, but the association between OSA and myocardial infarction (MI) remains controversial. Our objectives were to compare the frequency of OSA in patients with acute MI and in a population-based sample of control subjects, and to evaluate the impact of CPAP on recurrent MI and coronary revascularization. METHODS Case-control study with a 6-year follow-up of the case cohort. 192 acute MI patients and 96 matched control subjects without coronary artery disease (CAD) (ratio 2:1). After overnight polysomnography, CPAP was recommended if apnea-hypopnea index (AHI) ≥ 5, and a mean daily use >3.5h/day was considered necessary to maintain the treatment. Lipids, fasting glucose, blood pressure, spirometry, comorbidity and current treatment were also registered. End-points were recurrent MI or need of revascularization. RESULTS OSA was an independent predictor of MI, with odds ratio 4.9 (95% confidence interval [CI] 2.9-8.3, p=0.017). 63 MI patients without OSA, 52 untreated patients with OSA and 71 OSA patients treated with CPAP were included in the follow-up study. After adjustment for confounding factors, treated OSA patients had a lower risk of recurrent MI (adjusted hazard ratio 0.16 [95%CI 0.03-0.76, p=0.021]) and revascularization (adjusted hazard ratio 0.15 [95%CI 0.03-0.79, p=0.025]) than untreated OSA patients, and similar to non-OSA patients. CONCLUSION Mild-severe OSA is an independent risk factor for MI. Risk of recurrent MI and revascularization was lower in OSA patients who tolerated CPAP.

Recording the Daily Physical Activity of COPD Patients With an Accelerometer: An Analysis of Agreement and Repeatability

OBJECTIVE The purpose of this study was to assess the agreement between different measurements of mean daily physical activity taken over a week in chronic obstructive pulmonary disease (COPD) patients with an accelerometer and to analyze the medium-term repeatability of these measurements. PATIENTS AND METHODS The study enrolled 12 healthy control subjects and 23 patients with stable COPD (mean [SD] forced expiratory volume in 1 second [FEV1] of 45% [13%] of predicted and a ratio of FEV1 to forced vital capacity of 53% [13%]). Accelerometer output, measured in vector magnitude units, was recorded in a physical activity log for a 1-week period. The results were then analyzed to compare output for a conventional recording period (Friday to Sunday) to that for 2 other periods (Monday to Wednesday and Tuesday to Thursday). The measurements were repeated 3 to 5 weeks later. RESULTS Activity counts were lower in the COPD patients than in the control subjects (184 [99] vs 314 [75]; P < .001). In the COPD patients, the results for the Friday to Sunday period correlated well with the results for both the Monday to Wednesday period (95% confidence interval, -29.21 to 28.81) and the Tuesday to Thursday period (95% confidence interval, -32.13 to 28.43). There were no significant differences in terms of medium-term repeatability of accelerometer readings between the COPD group and the control group (repeatability coefficient of 11.2% [4.6%] and 8.5% [4.7%], respectively). CONCLUSIONS Both agreement between the different measurements of physical activity taken during a 1-week period and medium-term repeatability for COPD patients and control subjects were very good.

Influencia del sexo en las variables clínicas y polisomnográficas del síndrome de apneas del sueño

Objetivo Comparar, en una cohorte amplia de pacientes con sindrome de apneas-hipopneas durante el sueno, las caracteristicas clinicas, antropometricas y polisomnograficas en funcion del sexo. Pacientes y metodos En el estudio, realizado en 6 hospitales universitarios espanoles, se incluyo a pacientes consecutivos con un indice de apneas-hipopneas del sueno mayor de 5 h−1, que fueron evaluados entre 2003 y 2005. Se dividieron en funcion del sexo y, posteriormente, en funcion de la edad: pacientes jovenes (45 anos) y adultos (> 45 anos). Resultados Se ha estudiado a 2.464 varones y 424 mujeres. Las mujeres eran mayores (edad media ± desviacion estandar: 56 ± 12 frente a 51 ± 12 anos; p < 0,0001), pesaban mas (indice de masa corporal: 31 ± 6 frente a 30 ± 5 kg/m2; p < 0,0001) y presentaban una mayor circunferencia de cadera (119 ± 15 frente a 111 ± 12 cm; p < 0,0001) y una menor circunferencia de cuello (38 ± 3 frente a 42 ± 9 cm; p < 0,0001) que los varones. El grado de somnolencia diurna (escala de Epworth) y el indice de apneas-hipopneas eran similares en ambos grupos, aunque el de mujeres presentaba una latencia de sueno mas larga (23 ± 28 frente a 27 ± 32 min; p < 0,004) y una saturacion de oxigeno media (un 92 ± 4 frente a un 91 ± 5%) y minima menor (un 78 ± 11 frente a un 75 ± 12%; p < 0,0001) que los varones. Al diferenciar los grupos por edad, en el grupo de jovenes solo se mantenian las diferencias ponderales, mientras que entre los adultos reaparecian las diferencias en los valores de saturacion nocturna. Conclusiones Las mujeres con sindrome de apneas-hipopneas durante el sueno son mas obesas que los varones y consultan a una edad mas avanzada. Desde el punto de vista clinico y polisomnografico, no hay grandes diferencias en funcion del sexo. Unicamente la latencia de sueno es superior y la hipoxemia nocturna mas acentuada.

Effect of obstructive sleep apnoea on severity and short-term prognosis of acute coronary syndrome

The goal of this study was to evaluate the influence of obstructive sleep apnoea on the severity and short-term prognosis of patients admitted for acute coronary syndrome. Obstructive sleep apnoea was defined as an apnoea–hypopnoea index (AHI) >15 h−1. We evaluated the acute coronary syndrome severity (ejection fraction, Killip class, number of diseased vessels, and plasma peak troponin) and short-term prognosis (length of hospitalisation, complications and mortality). We included 213 patients with obstructive sleep apnoea (mean±sd AHI 30±14 h−1, 61±10 years, 80% males) and 218 controls (AHI 6±4 h−1, 57±12 years, 82% males). Patients with obstructive sleep apnoea exhibited a higher prevalence of systemic hypertension (55% versus 37%, p<0.001), higher body mass index (29±4 kg·m−2 versus 26±4 kg·m−2, p<0.001), and lower percentage of smokers (61% versus 71%, p=0.04). After adjusting for smoking, age, body mass index and hypertension, the plasma peak troponin levels were significantly elevated in the obstructive sleep apnoea group (831±908 ng·L−1 versus 987±884 ng·L−1, p=0.03) and higher AHI severity was associated with an increased number of diseased vessels (p=0.04). The mean length of stay in the coronary care unit was higher in the obstructive sleep apnoea group (p=0.03). This study indicates that obstructive sleep apnoea is related to an increase in the peak plasma troponin levels, number of diseased vessels, and length of stay in the coronary care unit. OSA is associated with an increase in the severity of acute coronary syndrome and extended coronary unit stay http://ow.ly/FEsBA

Comparación de la reinhalación de anhídrido carbónico originada por 3 mascarillas nasales durante la aplicación de CPAP

Se describe la fraccion end-tidal de anhidrido carbonico (F ET CO 2 ) originada con una mascarilla prototipo (Carburos Metalicos) durante la aplicacion de diferentes niveles de presion positiva continua en la via aerea (CPAP) y se compara con la desarrollada por 2 mascarillas nasales de uso habitual (Profile Lite y ComfortClassic, Respironics). En 11 voluntarios sanos, 12 pacientes con sindrome de apneas-hipopneas obstructivas durante el sueno de caracter grave y 12 enfermos hipercapnicos, se midio, de forma aleatoria en 3 dias sucesivos, la F ET CO 2 nasal despues de 3 min de CPAP a 4, 5, 6, 8, 10, 15 y 20 cmH 2 O con cada una de las mascarillas. Aunque en todos los casos se logro una reduccion progresiva de la F ET CO 2 al incrementar la presion, esta fue mayor con la mascarilla prototipo, para cualquier nivel de presion. En los 3 grupos del estudio las presiones alcanzadas en la mascarilla prototipo fueron similares a las generadas por la maquina de CPAP. En conclusion, la menor concentracion de anhidrido carbonico nasal durante la aplicacion de la mascarilla prototipo induce a pensar que origina una menor reinhalacion.