Mansukhani, Meghna P

Obstructive and central sleep apnea have been associated with increased risk of adverse cardiovascular events and mortality. Sympathetic dysregulation occurring as a result of the respiratory disturbance is thought to play a role in this increased risk. Sleep apnea increases the risk of arrhythmias, myocardial ischemia/infarction, stroke, and heart failure, all of which may increase mortality risk. A higher incidence of nocturnal arrhythmias, cardiac ischemia, and sudden death has been noted in subjects with sleep-disordered breathing (SDB). In this review, the association between SDB and each of these conditions is discussed, as well as the potential mechanisms underlying these risks and the effects of treatment of SDB. Particular emphasis is placed on the relationship between SDB and nocturnal atrial and ventricular arrhythmias, myocardial ischemia/infarction and sudden death.

New Findings What is the topic of this review? This review summarizes chemoreflex physiology in health and disease, with specific focus on chemoreflex‐mediated pathophysiology in obstructive and central sleep apnoea. What advances does it highlight? Chemoreflex mechanisms are thought to contribute significantly to the pathophysiology and adverse outcomes seen in sleep apnoea. Clinical implications of altered chemoreflex function in sleep apnoea from recent studies in humans, including cardiac arrhythmias, coronary artery disease, systolic/diastolic heart failure and sudden cardiac death are highlighted. Activation of the chemoreflex in response to hypoxaemia results in an increase in sympathetic neural outflow. This process is predominantly mediated by the peripheral chemoreceptors in the carotid bodies and is potentiated by the absence of the sympatho‐inhibitory influence of ventilation during apnoea, as is seen in patients with sleep apnoea. In these patients, repetitive nocturnal hypoxaemia and apnoea elicit sympathetic activation, which may persist into wakefulness and is thought to contribute to the development of systemic hypertension and cardiac and vascular dysfunction. Chemoreflex activation could possibly lead to adverse cardiovascular outcomes, such as nocturnal myocardial infarction, systolic and/or diastolic heart failure, cardiac arrhythmias and sudden death in patients with sleep apnoea. This review summarizes chemoreflex physiology in health and disease, with specific focus on chemoreflex‐mediated pathophysiology in obstructive and central sleep apnoea. Measurement of the chemoreflex response may serve as a potential avenue for individualized screening for cardiovascular disease. Whether modulation of this response in sleep apnoea may aid in the prevention and treatment of adverse cardiovascular consequences will require further study.

IntroductionUnderstanding the course and determinants of sleep disturbances in alcoholic patients may help identify patients at high risk of persistent sleep problems, relapse and guide treatment interventions.MethodsWe prospectively administered the Pittsburgh Sleep Quality Index (PSQI) to all patients (N = 196) admitted to a 1‐month residential treatment program. Our analysis excluded patients with active drug abuse/dependence. Demographic data, psychiatric diagnoses, Patient Health Questionnaire‐9 (PHQ‐9), Alcohol Use Disorders Identification Test (AUDIT) and Inventory of Drug Taking Situations (IDTS) scores were obtained. Univariate and logistic regression analyses were performed using sex, age, hazardous alcohol use, PHQ‐9 scores, hypnotic use, and use of alcohol as a hypnotic as correlates to admission PSQI scores and improvement in PSQI scores.ResultsA total of 119 alcoholic patients met inclusion criteria (mean age 50.6 ± 13.2 years). The rates of sleep disturbances at admission and discharge were 69.3% and 49.1%, respectively. Self report of using alcohol to fall asleep and use of hypnotics were associated with elevated PSQI scores. Total PSQI scores improved over 4 weeks (p < .001). Change in PSQI scores was not effected by gender, use of hypnotics, hazardous alcohol use, use of alcohol as a hypnotic or co‐morbid psychiatric diagnosis. Older age predicted improvement in PSQI scores in patients with sleep disturbances (p = .004).ConclusionWhile a large proportion of alcoholics had sleep disturbances upon admission and at discharge from a residential treatment program, only older age was associated with improvements in sleep disturbances during early alcohol recovery. (Am J Addict 2014;23:21–26)