We spend about one-third of our lives asleep, yet most of us know little about sleep. Although its function remains to be fully understood, sleep is a universal need of all higher life forms including humans, absence of which has serious physiological consequences.
Due to rapidly increasing knowledge about sleep in the 20th century, including the discovery of REM sleep in the 1950s and circadian rhythm disorders in the 70s and 80s, the medical importance of sleep was recognized more and more. The medical community began paying more attention than previously to primary sleep disorders, such as sleep apnea, as well as the role and quality of sleep in other conditions. By the 1970s in the USA, clinics and laboratories devoted to the study of sleep and sleep disorders had been founded, and a need for standards arose. Specialists in Sleep Medicine were originally certified by the American Board of Sleep Medicine, which still recognizes specialists. Those passing the Sleep Medicine Specialty Exam received the designation “Diplomate of the ABSM.” Sleep Medicine is now a recognized subspecialty within internal medicine, family medicine, pediatrics, otolaryngology, psychiatry and neurology in the United States.
There are two types of sleep, non-rapid eye movement (NREM) sleep and rapid eye movement (REM) sleep. NREM sleep is divided into stages 1, 2, 3, and 4, representing a continuum of relative depth. Each has unique characteristics including variations in brain wave patterns, eye movements and muscle tone. We also know about Circadian rhythms, the daily rhythms in physiology and behavior to regulate the sleep-wake cycle. In addition, the sleep-wake system is thought to be regulated by the interplay of two major processes, one that promotes sleep and one that maintains wakefulness.
As we increased our understanding of sleep, we discovered other abnormal conditions associated with sleep. The most common sleep disorders include: insomnia, OSA, restless leg syndrome, REM sleep behavior disorder, narcolepsy, sleep walking, sleep terrors and bruxism (Teeth grinding).
Obstructive sleep apnea (OSA), also known as Obstructive Sleep Apnea Syndrome or Obstructive Sleep Apnea- Hypopnea Syndrome is the second most common type of sleep disorder and is caused by complete or partial obstructions of the upper airway. It is characterized by repetitive episodes of shallow or paused breathing during sleep, despite the effort to breathe, and is usually associated with a reduction in blood oxygen saturation. These episodes of decreased breathing, called “apneas” (literally, “without breath”), typically last 20 to 40 seconds.
Obstructive sleep apnea (OSA) affects around 4% of men and 2% of women in the United States. In general, this disorder is more prevalent among men. However, this difference tends to diminish with age. Women experience the highest risk for OSA during pregnancy. In addition, they tend to report experiencing depression and insomnia in conjunction with obstructive sleep apnea.In a meta-analysis of the various Asian countries, India and China present the highest prevalence of the disorder. Specifically, about 13.7% of the Indian population and 7% of Hong-Kong’s population is estimated to have OSA. The two groups experience daytime OSA symptoms such as difficulties concentrating, mood swings, or high blood pressureat similar rates (prevalence of 3.5% and 3.57%, respectively).
OSA not only affects the quality of sleep, it has many serious consequences. In children it can cause many behavioral and learning problems as well as long term health problems in adult life. In adults it is also related to common problems as diabetes, hypertension and heart disease. As it is more common in obese people, the prevalence of it may be increasing in Myanmar.
Although there will be cases of OSA and its consequences health impact in Myanmar, we still do not have exact prevalence data in Myanmar. ZayYa Aye et.al. recently presented a paper on OSA in adults in the 65th Myanmar Medical Conference titled: “Analysis of demographic and pathophysiologic data among sleepy and non-sleepy adult OSA patients in Parami General Hospital.”
The leading article in this issue, “Obstructive Sleep Apnea (OSA)” by Win Naing et.al. highlighted the importance of this problem which needs more awareness in Myanmar. They have discussed the pathophysiology, clinical features, diagnosis and treatment of this increasingly important disease. The reader can also get the information about the currently available diagnostic and treatment facilities and services for their patients with suspected OSA.
