Day clinic vs. hospital care of pneumonia and severe malnutrition in children under five: a randomised trial.

Objectives: To evaluate the clinical outcomes and costs of managing pneumonia and severe malnutrition in a day clinic (DC) management model (outpatient) vs. hospital care (inpatient).

Methods: Randomised clinical trial where children aged 2 months to 5 years with pneumonia and severe malnutrition were randomly allocated to DC or inpatient hospital care.

Age-related changes in baroreflex sensitivity and cardiac autonomic tone in children mirrored by regional brain gray matter volume trajectories.

BackgroundThe baroreflex and central autonomic brain regions together control the cardiovascular system. Baroreflex sensitivity (BRS) decreases with age in adults. Age-related changes in brain regions for cardiovascular control in children are unknown.

Comparison of Endothelial Function in Asian Indians Versus Caucasians.

Background: Asian Indians have markedly increased mortality due to coronary artery disease (CAD). Impaired endothelial function has been linked to an increased risk of acute cardiovascular events. We tested the hypothesis that endothelial function was attenuated in Asian Indians and Caucasians.

Obstructive Sleep Apnea in Patients with Congenital Long QT Syndrome: Implications for Increased Risk of Sudden Cardiac Death.

Background: Congenital long QT syndrome (LQTS) is a familial arrhythmogenic cardiac channelopathy characterized by prolonged ventricular repolarization and increased risk of torsades de pointes-mediated syncope, seizures, and sudden cardiac death (SCD). QT prolongation corrected for heart rate (QTc) is an important diagnostic and prognostic feature in LQTS. Obstructive sleep apnea (OSA) has been increasingly implicated in the pathogenesis of cardiovascular disease, including arrhythmias and SCD.

Daytime cardiac repolarization in patients with obstructive sleep apnea.

Purpose: Obstructive sleep apnea (OSA) has been implicated in complications of cardiovascular disease, including arrhythmias and sudden cardiac death (SCD). Prolonged QT interval is associated with arrhythmias and SCD in patients with cardiovascular disease and apparently healthy humans. Apneic episodes during sleep in OSA patients are associated with QT prolongation due to increased vagal activity, but it is not understood whether chronic QT prolongation persists during normoxic daytime wakefulness.

Plasma renin levels and renin-blood pressure relationship in normal-weight and overweight children with obstructive sleep apnea and matched controls.

Background: Obstructive sleep apnea (OSA) has been increasingly linked to elevated blood pressure (BP) and hypertension. Repeated night-time hypoxia in OSA is associated with activation of two critical mechanisms of BP control: the autonomic nervous system and the renin-angiotensin system (RAS). The effects of OSA on the RAS are not well understood, especially in children.

Glucose, insulin, and insulin resistance in normal-weight, overweight and obese children with obstructive sleep apnea.

Background: Obstructive sleep apnea (OSA) is associated with components of metabolic syndrome. Both body weight and OSA independently influence metabolic measurements. The goal of this study was to determine whether OSA in normal-weight, overweight or obese children, compared to matched control groups, was associated with increased levels of glucose, insulin and insulin resistance (IR).

Severity of obstructive sleep apnea is associated with elevated plasma fibrinogen in otherwise healthy patients.

Purpose: Obstructive sleep apnea (OSA) has been implicated in both cardiovascular and cerebrovascular diseases. Systemic inflammation and coagulation may be related to cardiovascular pathophysiology in patients with OSA. Fibrinogen is a major coagulation protein associated with inflammation, and long-term elevated plasma fibrinogen is associated with an increased risk of major cardiovascular diseases.

Sympathetic nerve activity and simulated diving in healthy humans.

The goal of our study was to develop a simple and practical method for simulating diving in humans using facial cold exposure and apnea stimuli to measure neural and circulatory responses during the stimulated diving reflex. We hypothesized that responses to simultaneous facial cold exposure and apnea (simulated diving) would be synergistic, exceeding the sum of responses to individual stimuli. We studied 56 volunteers (24 female and 32 male), average age of 39 years.

Association between QRS duration and obstructive sleep apnea.

Background: Both obstructive sleep apnea (OSA) and prolonged QRS duration are associated with hypertension, heart failure, and sudden cardiac death. However, possible links between QRS duration and OSA have not been explored.

Methods: Cross-sectional study of 221 patients who underwent polysomnography at our center.

Diagnostic accuracy of the Berlin Questionnaire in detecting sleep-disordered breathing in patients with a recent myocardial infarction.

Background: The Berlin Questionnaire (BQ) has been used to identify patients at high risk for sleep-disordered breathing (SDB) in a variety of populations. However, there are no data regarding the validity of the BQ in detecting the presence of SDB in patients after myocardial infarction (MI). The aim of this study was to determine the performance of the BQ in patients after MI.

Gene-specific paradoxical QT responses during rapid eye movement sleep in women with congenital long QT syndrome.

Background: Patients with congenital long QT syndrome (LQTS) type 2 (LQT2) may develop arrhythmias during emotional stress, acoustic stimuli, or sleep. Women with LQT2 are more susceptible to fatal arrhythmias than are men.

Objective: The purpose of this study was to examine the effects of sleep on RR and QT intervals in patients with LQT1, in those with LQT2, and in controls and to test the hypothesis that there is a gene-specific effect of sleep on the QT interval in LQT2 that may be especially evident in women with LQT2.

Leptin upregulates the expression of plasminogen activator inhibitor-1 in human vascular endothelial cells.

A prothrombotic state in obesity may be partially responsible for the higher incidence of atherosclerotic complications. However the factors responsible for this prothrombotic state, linked with high levels of plasminogen activator inhibitor-1 (PAI-1), are not fully known. Leptin is elevated in obesity and studies have shown a positive correlation between leptin and PAI-1 levels in human subjects, along with a negative correlation with tissue-type plasminogen activator (tPA).

Baroreflex gain in children with obstructive sleep apnea.

Rationale: We previously demonstrated that children with obstructive sleep apnea have increased blood pressure associated with changes in left ventricular mass index. Others have shown in adults that blood pressure variability is an important predictor of changes in left ventricular mass. The baroreflex system buffers blood pressure changes by varying heart rate.

Leptin induces C-reactive protein expression in vascular endothelial cells.

Objective: There is increasing evidence of an association between leptin and increased cardiovascular risk. Higher leptin levels are associated with increased levels of C-reactive protein (CRP), which itself elicits proatherogenic effects in the vascular endothelium. We tested the hypothesis that leptin induces CRP expression in human coronary artery endothelial cells (HCAECs).

Ventricular ectopy during REM sleep: implications for nocturnal sudden cardiac death.

Background: A young adult female presented with syncope and periodic weakness. A 12-lead electrocardiogram showed frequent premature ventricular contractions and prolonged QU interval. Repetitive runs of nonsustained ventricular tachycardia were recorded at night.

Hemodynamic and autonomic effects of smokeless tobacco in healthy young men.

Objectives: The aim of this study was to investigate the acute hemodynamic and autonomic effects of smokeless tobacco.

Background: Smokeless tobacco use is increasing. Its cardiovascular effects are not well understood.

Erythropoietin and obstructive sleep apnea.

Objective: We tested the hypothesis that repetitive severe hypoxemia resulting from obstructive sleep apnea would increase serum erythropoietin, and that this increase would be attenuated by effective treatment of obstructive sleep apnea.

Methods: We studied healthy untreated patients with obstructive sleep apnea (18 severe and 10 very mild) before and after acute treatment with continuous positive airway pressure, and 12 healthy control subjects free of obstructive sleep apnea.

Results: Baseline erythropoietin levels before sleep were similar in the obstructive sleep apnea and control groups.

Plasma brain natriuretic peptide in obstructive sleep apnea.

We compared brain natriuretic peptide (BNP) levels in patients with obstructive sleep apnea (OSA) with and without cardiovascular disease to BNP in healthy control subjects. OSA was not associated with increased plasma BNP or atrial natriuretic peptide (ANP) in otherwise healthy subjects during wakefulness. Untreated OSA increased ANP overnight, and ANP levels decreased with treatment of OSA.

Plasma homocysteine in obstructive sleep apnoea.

Aims: Whether increased homocysteine is one mechanism linking obstructive sleep apnoea (OSA) to cardiovascular abnormalities is unclear. We hypothesised that plasma homocysteine would be higher in OSA patients than in control subjects, would increase further during sleep, and decrease after treatment with continuous positive airway pressure (CPAP).

Methods And Results: For study A, homocysteine was measured in 22 OSA patients and 20 controls first before sleep, then after 5 h of untreated OSA, and then in the morning after CPAP treatment.

Independent association between plasma leptin and C-reactive protein in healthy humans.

Background: C-reactive protein (CRP) is synthesized from the liver and is regulated by cytokines, especially interleukin-6. Leptin, the adipocyte-derived protein product of the ob gene, is related to amount of body fat. The long form of the leptin receptor resembles cytokine receptors, which include the interleukin-6 receptor.

Obesity, sleep apnea, and hypertension.

Obesity has a high and rising prevalence and represents a major public health problem. Obstructive sleep apnea (OSA) is also common, affecting an estimated 15 million Americans, with a prevalence that is probably also rising as a consequence of increasing obesity. Epidemiologic data support a link between obesity and hypertension as well as between OSA and hypertension.

Obstructive sleep apnea: implications for cardiac and vascular disease.

Context: Obstructive sleep apnea (OSA) has been increasingly implicated in the initiation and progression of cardiovascular diseases.

Objective: To systematically review the interactions of OSA with cardiovascular pathophysiology and diseases.

Data Sources And Study Selection: The MEDLINE database from January 1966 to March 2003 was searched using the Medical Subject Headings sleep, sleep apnea, obesity, hypertension, heart failure, cardiac arrhythmia, coronary artery disease, stroke, sympathetic activity, endothelium, inflammation, and continuous positive airway pressure (CPAP) to identify peer-reviewed studies of OSA.

Serum amyloid a in obstructive sleep apnea.

Background: Patients with severe obstructive sleep apnea (OSA) may have increased risk for cardiovascular and cerebrovascular diseases. Serum amyloid A (SAA) protein has recently been linked to the development of atherosclerosis, stroke, diabetes, and dementia. We tested the hypothesis that plasma SAA levels are increased in otherwise healthy subjects with OSA.