Inverse relationship of subjective daytime sleepiness to mortality in heart failure patients with sleep apnoea.

Aims: Patients with sleep apnoea (SA) and heart failure (HF) are less sleepy than SA patients without HF. HF and SA both increase sympathetic nervous system activity (SNA). SNA can augment alertness.

The Prioritization of Clinical Risk Factors of Obstructive Sleep Apnea Severity Using Fuzzy Analytic Hierarchy Process.

Recently, there has been a problem of shortage of sleep laboratories that can accommodate the patients in a timely manner. Delayed diagnosis and treatment may lead to worse outcomes particularly in patients with severe obstructive sleep apnea (OSA). For this reason, the prioritization in polysomnography (PSG) queueing should be endorsed based on disease severity.

Overnight Effects of Obstructive Sleep Apnea and Its Treatment on Stroke Volume in Patients With Heart Failure.

Background: We previously showed in heart failure (HF) patients that obstructive respiratory events during sleep and generation of negative intrathoracic pressure during Mueller manoeuvres, mimicking obstructive apneas, acutely reduced stroke volume (SV). We also showed that treating obstructive sleep apnea (OSA) with continuous positive airway pressure (CPAP) increased left ventricular ejection fraction over a 1-month period. We therefore hypothesized that, in HF patients, those with OSA would have greater overnight declines in SV and cardiac output (CO) than in those without sleep apnea, and that therapy of OSA using CPAP would prevent these declines.

Reliability and validity of the Thai version of the Pittsburgh Sleep Quality Index.

Objective: To assess the internal consistency, test-retest reliability, and validity of the Thai version of the Pittsburgh Sleep Quality Index (Thai-PSQI), which was recently translated using a standardized method, in Thai patients with major sleep disorders.

Material And Method: The Thai-PSQI was developed under a standard translation protocol and administered to "bad" sleepers (i.e.

Severe obesity is a risk factor for severe obstructive sleep apnea in obese children.

Objective: To determine the association between degree of obesity and severity of OSA in Thai children

Material And Method: The present retrospective study recruited obese children aged 3 to 15 years who had habitual snoring and underwent polysomnography (PSG) between January 2009 and June 2010. Obesity was defined as percentage of ideal weight for height (%W/H) > or = 120 and was classified as mild (%W/H of 120-139), moderate (140-159), severe (160-199) and morbid (> or = 200). OSA was classified as severe (AHI > or = 10) and non-severe (AHI < 10).

Relation of periodic leg movements during sleep and mortality in patients with systolic heart failure.

Periodic leg movements during sleep (PLMs) are a disorder characterized by regularly recurring movements of the legs during sleep. Although PLMs are common in patients with heart failure (HF), their clinical significance is unknown. The aim of this study was to determine whether, in patients with HF, PLMs are associated with increased mortality risk.

Nocturnal rostral fluid shift: a unifying concept for the pathogenesis of obstructive and central sleep apnea in men with heart failure.

Background: Obstructive sleep apnea (OSA) and central sleep apnea are common in patients with heart failure. We hypothesized that in such patients, severity of OSA is related to overnight rostral leg fluid displacement and increase in neck circumference, severity of central sleep apnea is related to overnight rostral fluid displacement and to sleep Pco(2), and continuous positive airway pressure alleviates OSA in association with prevention of fluid accumulation in the neck.

Methods And Results: In 57 patients with heart failure (ejection fraction View Article and Find Full Text PDF

Independent association of drug-resistant hypertension to reduced sleep duration and efficiency.

Background: Experimentally induced sleep deprivation can raise blood pressure (BP) and worsen hypertension. We recently reported a significantly higher prevalence of obstructive sleep apnea (OSA) and reduced rapid eye movement (REM) sleep time in drug-resistant hypertensives compared to controlled hypertensives. The objective of this study was to test the hypothesis that short sleep duration is associated with resistant hypertension (RH) independently of OSA, which can itself disrupt and shorten sleep.

Association between refractory hypertension and obstructive sleep apnea.

Background: Obstructive sleep apnea (OSA) increases the risk for mild hypertension, but its relationship to refractory hypertension (RHT) has not been systematically examined. We previously reported a high prevalence of OSA in patients with RHT, but did not have a control group with which to compare. Rapid eye movement (REM) sleep deprivation can raise blood pressure in animals.

Prevalence and physiological predictors of sleep apnea in patients with heart failure and systolic dysfunction.

Background: Previous studies reported high prevalences of obstructive and central sleep apnea (OSA and CSA, respectively) in patients with heart failure (HF). However, these preceded widespread use of beta-blockers and spironolactone that might have reduced their prevalences. We therefore determined, in patients with HF, prevalences and predictors of OSA and CSA and the influence of changes in HF therapy on prevalences.

Effect of continuous positive airway pressure on sleep structure in heart failure patients with central sleep apnea.

Study Objectives: At termination of obstructive apneas, arousal is a protective mechanism that facilitates restoration of upper airway patency and airflow. Treating obstructive sleep apnea (OSA) by continuous positive airway pressure (CPAP) reduces arousal frequency indicating that such arousals are caused by OSA. In heart failure (HF) patients with central sleep apnea (CSA), however, arousals frequently occur several breaths after apnea termination, and there is uncertainty as to whether arousals from sleep are a consequence of CSA.

Relationship between overnight rostral fluid shift and Obstructive Sleep Apnea in nonobese men.

Rationale: The cause of increased pharyngeal collapsibility in patients with obstructive sleep apnea is incompletely understood. In awake healthy subjects, we showed that fluid displacement from the legs into the neck induced by lower body positive pressure reduces upper airway size and increases its collapsibility. Prolonged sitting leads to dependent fluid accumulation in the legs.

Difference in upper airway collapsibility during wakefulness between men and women in response to lower-body positive pressure.

Fluid shift from the legs to the neck induced by LBPP (lower-body positive pressure) increases UA (upper airway) collapsibility in healthy men. Rostral fluid displacement during recumbency may therefore contribute to the pathogenesis of OSA (obstructive sleep apnoea). There is a higher prevalence of OSA in men than in women.

Sustained effect of continuous positive airway pressure on baroreflex sensitivity in congestive heart failure patients with obstructive sleep apnea.

Background: Patients with either heart failure or obstructive sleep apnea have a reduced baroreflex sensitivity for heart rate, a sign of poor prognosis. We previously demonstrated that nocturnal application of continuous positive airway pressure to heart failure patients with obstructive sleep apnea increased baroreflex sensitivity acutely, but it is not known whether these effects persist into wakefulness.

Objective: To determine whether treating obstructive sleep apnea in heart failure patients with continuous positive airway pressure improves baroreflex sensitivity during wakefulness.

Comparison of clinical and polysomnographic characteristics of non-obese and obese patients with obstructive sleep apnea.

Objective: To compare the clinical features, anthropometric indices, and polysomnographic data between different body mass index (BMI) subgroups of obstructive sleep apnea (OSA) patients.

Material And Method: The authors reviewed the data from OSA patients in Siriraj Sleep Clinic from April 2005 to September 2006. Objective measurement for sleepiness (Epworth Sleepiness Scale, ESS), anthropometric measurements [body mass index (BMI), neck circumference, thyromental distance, Mallampati S score, and occlusion pattern] and polysomnographic recordings [apnea/hypopnea index (AHI) during REM and NREM periods, respiratory arousal index, periodic leg movement index, minimal oxygen saturation, total sleep time with oxygen saturation <90%, and desaturation index] were collected.

Alterations in upper airway cross-sectional area in response to lower body positive pressure in healthy subjects.

Background: Fluid accumulation in the neck during recumbency might narrow the upper airway (UA) and thereby contribute to its collapse in patients with obstructive sleep apnoea (OSA). It is hypothesised that acute fluid shifts from the legs to the upper body in healthy subjects would increase neck circumference and reduce the cross-sectional area of the UA (UA-XSA).

Methods: In 27 healthy non-obese subjects of mean (SE) age 39 (3) years and body mass index 23.

Influence of obstructive sleep apnea on mortality in patients with heart failure.

Objectives: This study sought to determine, in patients with heart failure (HF), whether untreated moderate to severe obstructive sleep apnea (OSA) is associated with a higher mortality rate than in patients with mild to no sleep apnea (M-NSA).

Background: Obstructive sleep apnea is common in patients with HF and exposes the heart and circulation to adverse mechanical and autonomic effects. However, its effect on mortality rates of patients with HF has not been reported.

Fluid shift by lower body positive pressure increases pharyngeal resistance in healthy subjects.

Introduction: Fluid displacement into nuchal and peripharyngeal soft tissues while recumbent may contribute to narrowing and increased airflow resistance of the pharynx (Rph), and predispose to pharyngeal collapse in patients at risk for obstructive sleep apnea.

Objectives: To determine whether displacement of fluid from the lower body to the neck will increase both neck circumference and Rph in healthy subjects.

Methods: In 11 healthy, nonobese subjects, studied while awake and supine, leg fluid volume, neck circumference, and Rph were measured at baseline.

Prevalence of bronchial hyperresponsiveness and asthma in the adult population in Thailand.

Objectives: We conducted a nationwide cross-sectional survey of respiratory health in adults aged 20 to 44 years during 2001 to 2002 to determine the prevalence of bronchial hyperresponsiveness (BHR) and asthma in the adult Thai population.

Design: Subjects were selected by a multistage stratified random sampling. The stratification was done on geographic area, age group, and sex.