Sleep disorders 3

Where can I get more information? Introduction Sleep is an important part of your daily routine—you spend about one-third of your time doing it. Quality sleep — and getting enough of it at the right times -- is as essential to survival as food and water. Sleep is important to a number of brain functions, including how nerve cells neurons communicate with each other.

Sleep disorders 3

BOX Definitions Impact Disease Prevalence Estimates The metric used most commonly to define obstructive sleep apnea and to quantify its severity is the apnea-hypopnea index, derived by identifying and manually counting each respiratory disturbance apnea and hypopnea with subsequent division of the sum by the number of hours slept.

Technology for measuring changes in airflow and ventilatory effort has evolved rapidly, with laboratories varying in the implementation of specific sensors and scoring approaches for identifying respiratory events. Variation in event identification has been particularly great for hypopneas Moser et al.

Likewise, there has been variation in the choice of threshold values for the apnea-hypopnea index considered to define the disease state. An analysis of over 5, records from the Sleep Heart Health Study underscores the potential variability introduced by varying either hypopnea definitions or threshold values.

This analysis showed that the magnitude of the median apnea-hypopnea index varied fold i. Using any given definition but varying the threshold to define disease also resulted in marked differences in the percentage of subjects classified as diseased. For example, using an apnea-hypopnea index cutoff value of greater than 15 and an apnea-hypopnea index definition requiring a 5 percent level of desaturation resulted in a prevalence estimate of These data and others have Sleep disorders 3 the critical need for standardization.

As such, at least three efforts led by professional organizations have attempted to develop standards. The latest efforts by the American Academy of Sleep Medicine have attempted to apply evidence-based guidelines to the recommendations. Unfortunately, the lack of prospective studies that allow various definitions to be compared relative to predictive ability have limited these initiatives, resulting in some recommendations reflecting consensus or expert opinion that may change as further research is developed.

Page 68 Share Cite Suggested Citation: Sleep Disorders and Sleep Deprivation: An Unmet Public Health Problem. The National Academies Press.

Sleep disorders 3

The Sleep Heart Health Study is a community-based multicenter study of more than 6, middle-aged and older adults whose apnea-hypopnea index was measured by polysomnography. The likelihood of hypertension was greater at higher apnea-hypopnea index levels. Case-control studies reveal that approximately 30 percent of patients diagnosed with essential hypertension hypertension in which the underlying cause cannot be determined turn out to have sleep apnea Partinen and Hublin, Further, evidence from pediatric studies indicate elevations in systemic blood pressure during both wakefulness and sleep in children with sleep apnea Amin et al.

The causal nature of the relationship between OSA and hypertension is reinforced by randomized controlled clinical trials showing that the most effective treatment for OSA, continuous positive airway pressure CPAP therapy, can reduce blood pressure levels.

The benefit is greatest in patients with severe OSA, determined by objective polysomnography and subjective daytime sleepiness criteria. The review also concluded that there was a lack of benefit in patients who had no daytime sleepiness Robinson et al. However, each of these studies was relatively small less than individualsand findings can be considered only tentative.

How does OSA cause sustained hypertension? During the night, the apneas and hypopneas of OSA cause a transient rise in blood pressure 30 mm Hg or more and increased activity of the sympathetic nervous system Figure Over time, the transient changes become more sustained and are detectable during the daytime, including evidence of sympathetic overactivity Narkiewicz and Somers, Studies have found that people with OSA versus those with similar blood pressure, but no OSA have faster heart rates, blunted heart rate variability, and increased blood pressure variability—all of which are markers of heightened cardiovascular risk Caples et al.

The precise pathophysiological steps from transient vascular changes to systemic hypertension are far from clear but may involve oxidative stress, upregulation of vasoactive substances Caples et al. Page 69 Share Cite Suggested Citation: During even the lowest phase, blood pressure during REM was higher than in the awake state.

Most case-control studies detecting a relationship with myocardial infarction found adjusted odds ratios of around 4 Young et al.

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The adjusted OR for stroke was 1. A higher probability of stroke associated with OSA is also supported by other studies Bassetti and Aldrich, ; Parra et al. That the hypertension adjustment did not eliminate the effect suggests that hypertension is not the exclusive means by which OSA may lead to cardiovascular disease.

A limitation of cross-sectional and case-control analyses is that cause and effect cannot be determined: However, an observational cohort study of 1, individuals, where 68 percent of individuals had OSA apnea-hypopnea index of 5 or highershowed that OSA syndrome significantly increased the risk of stroke or death from any cause, and the increase is independent of other risk factors, including hypertension Yaggi et al.

Other studies have confirmed the risk of OSA syndrome with stroke or death from any cause Ayas et al. Furthermore, other large prospective studies also have shown an association between snoring—a marker for OSA—and incidence of cardiovascular diseases Jennum et al. As will be discussed in the next section, OSA is associated with glucose intolerance and diabetes, both of which are independent risk factors for cardiovascular disease.


The events included myocardial infarction, stroke, and coronary artery bypass surgery. The untreated patients had refused CPAP but were followed regularly. A second study found an increased mortality rate from cardiovascular disease in individuals who did not maintain CPAP treatment over a 5-year follow-up period Doherty et al.Oct 22,  · Introduction.

Sleep is an important part of your daily routine—you spend about one-third of your time doing it. Quality sleep – and getting enough of it at the right times -- is as essential to survival as food and water.

Sleep disorders are characterized by any conditions that prevent a person from getting restful sleep. The dangerous part isn’t the actual sleep loss, but the dysfunction it causes during the waking hour when we are operating motor vehicles, work-associated machinery, and so forth.

Sleep health information from the American Academy of Sleep Medicine. Symptoms and treatments for insomnia, sleep apnea and sleep disorders.

Find a sleep center for help sleeping. Getting enough sleep is not a luxury—it is something people need for good health. Sleep disorders can also increase a person’s risk of health problems. However, these disorders can be diagnosed and treated, bringing relief to those who suffer from them.

Nov 19,  · Sleep health is a particular concern for individuals with chronic disabilities and disorders such as arthritis, kidney disease, pain, human immunodeficiency virus (HIV), epilepsy, Parkinson’s disease, and depression.

A sleep disorder, or somnipathy, is a medical disorder of the sleep patterns of a person or animal. Some sleep disorders are serious enough to interfere with normal .

Sleep Disorders | Cleveland Clinic