Sleep Medicine is a relatively young field with the first clinical sleep centers opening in the 1970s, and the only treatment options for sleep apnea at that time was a tracheostomy, a surgical opening into the airway. Subsequent decades have seen a dramatic expansion in research, and health professional and public awareness of the importance of sleep and its disorders to many aspects of health. While the influences of sleep disturbance are myriad, particular progress is occurring in understanding the connections between sleep and cardiovascular and metabolic diseases. As the importance of sleep becomes increasingly understood, researchers and clinicians are now also recognizing that a personalized approach to management is required and that a one-sized treatment strategy will likely fail both to target individuals in greatest need and to offer options that are acceptable and effective.
Surveys have consistently identified widely prevalent patterns of insufficient sleep duration, in large part driven by nighttime electronic screen time. While it is evident that insufficient sleep will affect next-day performance, new data is indicating direct effects on health as well. In the National Health Interview Survey of 70,000 individuals, there was a progressive increase in the rates of high blood pressure as sleep duration decreased. Restricting sleep in healthy young volunteers in the laboratory setting demonstrates a loss of the normal “dipping” response in blood pressure that should occur during sleep. Insufficient time for sleep has been shown to increase the rate of coronary artery disease and fatal cardiac events. It is known both in laboratory settings and population surveys to promote blood sugar elevation, weight gain, and obesity.
"The need for a personalized approach relative to the genetic, psychosocial, and other unique qualities of an individual is increasingly advocated in medicine and this is also being adopted by the field of Sleep Medicine"
An expanding body of research is also exploring how the disturbance of sleep quality creates adverse cardiovascular effects. Obstructive sleep apnea is tightly linked to high blood pressure, coronary artery disease, cardiac arrhythmias, heart failure, and stroke. An increased incidence of coronary artery disease is found in workers who contend with the disturbance of sleep seen in shift workers. Chronic insomnia is now known to correlate with an increased risk of both heart attack and stroke.
Not all segments of the population bear these adverse effects of insufficient and inadequate sleep equally, however. Genetic and gender differences in the prevalence of abnormal sleep and susceptibility are being investigated. African Americans have been consistently shown to have a reduced sleep duration relative to other racial groups and also suffer from both a higher frequency and severity of obstructive sleep apnea. These disparities in sleep likely play an essential role in the increased burden of cardiovascular disease and early mortality experienced by the population. For this reason, public health measures addressing sleep disturbance in the African American community offer targeted efforts most likely to have the biggest “bang for the buck.”
The need for a personalized approach relative to the genetic, psychosocial, and other unique qualities of an individual is increasingly advocated in medicine, and the field of Sleep Medicine is also adopting this. Its necessity is highlighted by results of a recent large study known as the Sleep Apnea Cardiovascular Endpoints (SAVE) trial. Despite the expanding body of data showing adverse cardiovascular effects from sleep apnea, this study failed to demonstrate an ability to prevent outcomes such as heart attack and stroke in the group of patients given the most common treatment for sleep apnea, a CPAP machine. These results suggest two important questions need attention: 1, which specific characteristics identify individuals at greatest risk for adverse effects from a sleep disorder such as sleep apnea and 2. How can we individualize and improve the response to treatment? In part, the lack of response to treatment in SAVE may have reflected that patients treated with CPAP used their machines less than 4 hours a night and were not getting effective control of the condition.
Efforts are underway to improve the comfort and compliance of patients with sleep apnea being treated with CPAP with improvements in the technology. Additionally, individualized alternative treatment approaches are being designed to meet some patient’s specific needs. These include options such as sleep position training, weight loss or upper airway surgery, dental appliances worn at night, and a recently developed neurostimulator device for the upper airway.
In conclusion, we are waking up to the importance of sleep not only to quality of life but also to its significant effects on health such as cardiovascular outcomes. Sleep Medicine increasingly recognizes our need to get personal with the decisions as to when whom and how to treat a sleep disorder.