![]() During sleep, ventilation becomes tightly linked with metabolic rate, oxygen consumption (V O 2), and carbon dioxide (CO 2) production (V CO 2), with behavioral influences being minimal to absent. As a result, workload on the heart is reduced and the cardiovascular system is in hemodynamic and autonomic quiescence. As one progresses into deeper sleep, parasympathetic nervous system tone increases while sympathetic nervous system activity, along with heart rate, blood pressure, and systemic vascular resistance decreases. The transition from wakefulness to NREM sleep is accompanied by marked alterations in respiratory and cardiovascular regulation. During normal sleep, these stages tend to occur in succession from wakefulness, into stage 1 sleep, followed by stage 2, 3, and 4, and then REM sleep. NREM sleep is further classified into four stages: stage 1 (light sleep), stage 2 (consolidated sleep), and stage 3 and 4 (deep, or slow-wave sleep). To better understand how sleep disorders may affect cardiovascular physiology, it is important to examine the normal physiology of sleep and arousal.īased on electroencephalogram (EEG) and other physiologic measurements, sleep is divided into two distinct states: rapid eye movement (REM) sleep and non–rapid eye movement (NREM) sleep. This finding suggests that health care providers would have a high yield in the Review of Systems when asking their patients about sleep problems.īesides excessive daytime sleepiness and loss of productivity, many studies have suggested that sleep disorders cause important cardiovascular morbidity and possibly mortality. In a Gallup Poll performed in 1995, 70% of American adults who claimed to have sleep problems stated that they never discussed these problems with a health care provider. It is estimated that nearly 80 million Americans will have a sleep problem by the year 2010 and 100 million will by the year 2050. With sleep disorders apparently more prevalent among the elderly, the graying of the United States population suggests that an increasing public health burden will be encountered in the years to come. Other studies have confirmed similar numbers. ![]() The commission proposed that the direct cost of sleep disorders approached 16 billion dollars, with reduced workplace productivity costing an estimated 150 billion dollars. ![]() Sleep apnea alone was the cause of excessive daytime sleepiness in almost 20 million Americans, making it more prevalent than asthma in adults. According to the research, 40 million Americans were chronically ill with various sleep disorders, with an additional 20 to 30 million experiencing intermittent sleep-related problems. The Commission published its findings in 1993, highlighting the extensive prevalence and health and economic impacts of sleep disorders in our country. With increasing awareness that sleep disorders were posing a major public health problem, the United States Congress in 1988 created the National Commission on Sleep Disorders Research to assess the status of research and knowledge regarding sleep disorders, including available resources and facilities to address these problems. Sleep disorders can be classified into one of four groups: insomnias, hypersomnias, parasomnias, and sleep–wake schedule disorders. Although obstructive sleep apnea is probably the most well known, the disorders that can occur during sleep are diverse and often underdiagnosed or misdiagnosed. Thomas Dekker (1572–1632)Īlthough the importance of sleep and well-being has been known for centuries, only recently has the medical profession begun to focus on sleep disorders and their effects. The golden chain that ties health and our bodies together.
0 Comments
Leave a Reply. |