Nocturnal blood pressure dipping and beta-adrenergic receptor sensitivity.

Background: Blunted nocturnal blood pressure (BP) dipping has been observed in patients with various cardiovascular pathophysiology. However, the mechanisms underlying relationships between blunted dipping and pathophysiologic end points remain unclear. This study examined relationships between beta-adrenergic receptor sensitivity and nocturnal BP dipping.

Association between polysomnographic sleep measures and health-related quality of life in obstructive sleep apnea.

Many facets of health-related quality of life are diminished in obstructive sleep apnea (OSA) as they are in other chronic medical conditions. We speculated that impairment in health-related quality of life (HRQoL) might result from the fatigue and daytime somnolence associated with the sleep disorder, as an indirect result from the fragmentation of night-time sleep in OSA. Our hypothesis was that sleep fragmentation measures would correlate with poorer HRQoL measured by medical outcomes study (MOS) subscales.

Opioids, sleep, and cancer-related fatigue.

Oddly enough, little is known about the effects on sleep of commonly administered analgesic medications. Even less is known about their effect on next-day fatigue, mood, and cognitive functioning. We speculate that part of the fatigue typically experienced by cancer patients can be attributed to disruption of sleep by opioid medications they are taking.

Peripheral blood mononuclear cell CD62L and CD11a expression and soluble interstitial cell adhesion molecule-1 levels following infused isoproterenol in hypertension.

Objectives: Increasingly, studies indicate that alterations in leukocyte and endothelial cell adhesion molecules may enhance atherosclerotic processes in human hypertension. beta-adrenergic receptor activation has long been implicated in the aetiology and/or maintenance of hypertension and also has significant effects on leukocyte and endothelial adhesion molecules. This study therefore examined the effects of hypertension on peripheral blood mononuclear cell CD62L and CD11a expression and circulating soluble interstitial cell adhesion molecule (ICAM)-1 (sCD54) levels following infusion of the non-specific beta-adrenergic agonist isoproterenol.

Types of coping strategies are associated with increased depressive symptoms in patients with obstructive sleep apnea.

Study Objectives: Some, but not all, researchers report that obstructive sleep apnea (OSA) patients experience increased depressive symptoms. Many psychological symptoms of OSA are explained in part by other OSA comorbidities (age, hypertension, body mass). People who use more passive and less active coping report more depressive symptoms.

Response bias influences mental health symptom reporting in patients with obstructive sleep apnea.

The Medical Outcomes Study (MOS) inventory is widely used to assess quality of life in chronically ill patients. Although response bias was addressed during its initial validation, we are unaware ofsubsequent studies examining how personality characteristics influence responses on this instrument. We examined the impact of response bias on MOS data reported by 44 obstructive sleep apnea (OSA) outpatients who completed the MOS and Marlowe-Crowne Social Desirability Scale (MC).

Decrease in the plasma von Willebrand factor concentration following glucose ingestion: the role of insulin sensitivity.

Elevated plasma von Willebrand factor (vWF) concentration is thought to be associated with increased prevalence of cardiovascular events in the insulin resistance syndrome. We examined the effects of oral glucose challenge and accompanying metabolic and hemodynamic changes on vWF levels with respect to insulin sensitivity. Forty normotensive and hypertensive subjects (mean age +/- SD, 40 +/- 5 years) underwent a standard oral glucose tolerance test (OGTT).

Sleep quality and blood pressure dipping in obstructive sleep apnea.

Background: Obstructive sleep apnea (OSA) is associated with poor sleep quality and a high incidence of nondipping. The aim of this study was to determine the association of sleep quality and nocturnal blood pressure (BP) dipping in an OSA population.

Methods: A total of 44 untreated subjects with mild to severe OSA underwent overnight-attended polysomnography and 24-h ambulatory BP monitoring.

Effect of continuous positive airway pressure and placebo treatment on sympathetic nervous activity in patients with obstructive sleep apnea.

Study Objectives: We studied the effect of continuous positive airway pressure (CPAP) treatment on sympathetic nervous activity in 38 patients with obstructive sleep apnea.

Design: Randomized, placebo-controlled trial.

Setting: Patients underwent polysomnography on three occasions in a clinical research center, and had BP monitored over 24 h at home.

The hypercoagulable state in sleep apnea is related to comorbid hypertension.

Objective: Obstructive sleep apnea (OSA) is associated with increased prevalence of atherosclerotic disease. A hypercoagulable state thought to underly atherosclerosis has been described in both OSA and systemic hypertension. We wondered about the respective contribution of apnea and hypertension to a hypercoagulable state.

Neuropsychological effects of one-week continuous positive airway pressure treatment in patients with obstructive sleep apnea: a placebo-controlled study.

Objective: To determine whether 1-week continuous positive airway pressure (CPAP) treatment, compared with placebo CPAP, improves cognitive functioning in patients with obstructive sleep apnea (OSA).

Methods: 36 OSA patients (aged 32-60 years, respiratory disturbance index [RDI] > 15) were monitored 2 nights with polysomnography, then randomized for 1-week treatment to CPAP or placebo (CPAP at 2 cm H2O with holes in mask). Participants completed Wechsler Adult Intelligence Scale-Revised Digit Symbol and Digit Span, Trailmaking A/B, Digit Vigilance, Stroop Color-Word, Digit Ordering, and Word Fluency tests pre- and posttreatment.

Effects of psychological stress and psychiatric disorders on blood coagulation and fibrinolysis: a biobehavioral pathway to coronary artery disease?

Objective: A hypercoagulable state before overt thrombosis resulting from an imbalance between the coagulation and fibrinolysis systems is related to cardiovascular disease progression and acute coronary syndromes. Psychological stressors and depressive and anxiety disorders also are associated with coronary artery disease. This review explores whether changes in blood coagulation, anticoagulant, and fibrinolytic activity may constitute psychobiological pathways that link psychological factors with coronary syndromes.

Short-term hyperglycemia induces lymphopenia and lymphocyte subset redistribution.

Alterations in lymphocytes are a common finding in both type I and type II diabetes. Autoimmune phenomena in type I diabetes, the stage of the diabetic disorder and metabolic effects of therapeutic interventions may also affect actual distribution of lymphocyte phenotypes. This study investigated immunological effects specific to standardized hyperglycemia in non-diabetic individuals to exclude immunological changes potentially related to diabetes stage and treatment.

Mood states and impedance cardiography-derived hemodynamics.

Objective: This exploratory study investigated the relation between psychological mood states and hemodynamic variables obtained at rest.

Methods: We measured resting hemodynamic variables using impedance cardiography, blood pressure, heart rate, and the Profile of Mood States (POMS) in 71 participants.

Results: Mood states were not significantly associated with heart rate, systolic, diastolic, or mean arterial pressure.

Continuous positive airway pressure normalizes cardiac autonomic and hemodynamic responses to a laboratory stressor in apneic patients.

Objectives: We examined the effect of continuous positive airway pressure (CPAP) treatment for sleep apnea on cardiac contractility, heart rate variability, and hemodynamics at rest and in response to a laboratory stressor. SUBJECTS AND INSTRUMENTATION: Forty-one apneic patients were studied on three occasions: before treatment, after 1 full night of CPAP treatment, and after 1 week of CPAP treatment. The subjects were randomly assigned to receive effective treatment or placebo.

The effects of hypoxia and sleep apnea on isoproterenol sensitivity.

Study Objectives: To determine the effects of both apnea and hypoxia on beta-adrenergic receptor sensitivity.

Design: Cross-sectional study.

Setting: A clinical research center.

Effects of sympathetic activation by adrenergic infusions on hemostasis in vivo.

Overactivity of the sympathetic nervous system (SNS) has been related to increased cardiovascular morbidity. Historical reports suggest hastening of blood coagulation following intravenous administration of epinephrine. Given the important role of the hemostatic system in atherosclerosis and thrombosis, it is surprising that short-term adrenergic effects on blood coagulation, fibrinolysis and platelet activity have not been scrutinized closely.

Obstructive sleep apnea and hypertension: are peripheral chemoreceptors involved?

The mechanism of pathogenesis of hypertension in patients with obstructive sleep apnea (OSA) is unknown. Many investigators point to the high sympathetic nervous system activity (SNS) observed in OSA patients. However, there is no clear explanation as to the mechanism for the development of SNS hyperactivity in these patients.

Peripheral blood mononuclear cell-endothelial adhesion in human hypertension following exercise.

Objective: To determine the effects of hypertension and exercise on interleukin-6 (IL-6) levels and mononuclear cell adhesion to endothelial cells.

Design: Twelve hypertensive and 33 normotensive volunteers were studied prior to and following exhaustive exercise. End points were stimulated IL-6 levels and peripheral blood mononuclear cell (PBMC) CD11a (LFA-1) expression and in vitro PBMC adhesion to human umbilical venous endothelial cells (HUVEC).