Sleep and cardiovascular diseases in the elderly

Introduction Sleep has been ascribed a restorative function for the body and mind, and is pivotal for maintenance of normal health. Sleep disorders are common in the elderly with a symptom prevalence rate approaching 50% in elderly community populations. Cardiovascular disease is the leading cause of death in the elderly as well as for all adults over age 35 years. Therefore, it is not surprising that diverse physiological and pathological changes associated with sleep may contribute to cardiovascular morbidity, particularly with increasing age. Variability in autonomic activity during different sleep stages leads to changes in cardiac output, blood pressure, and heart rate. This may tax the cardiovascular system and be conducive to augmented morbidity and mortality. The incidence of adverse cardiovascular events is particularly elevated during the early morning hours (06:00 to 12:00). Up to 20% of myocardial infarctions and 15% of sudden cardiac deaths may be sleep related. Habitual snoring, a form of sleep disordered breathing (SDB, see below), has been demonstrated to be a risk factor for early morning cardiovascular deaths. Moreover, daytime sleepiness is associated with cardiovascular morbidity and mortality in older adults, especially in older women. Obstructive sleep apnea (OSA), a frequent form of SDB, is associated with commonly occurring cardiovascular disorders, including hypertension, coronary artery disease, congestive heart failure (CHF), arrhythmias, and stroke. The concordance of OSA and cardiovascular disorders is independent of obesity and other cardiovascular disease risk factors.