Roughly one in ten adults aged 30 to 69 may stop breathing in their sleep
A 2019 analysis estimated that obstructive sleep apnea affects between 936 million and a billion people aged 30 to 69 worldwide. Many never realise it; a partner often notices first, hearing the snoring stop, a silence, then a snort as breathing restarts. Each pause jolts the brain awake just enough to reopen the airway.
Sleep apnea is a breathing disorder in which breathing repeatedly pauses or becomes shallow during sleep, sometimes for seconds and sometimes for minutes, many times a night. The obstructive type, by far the most common, happens when the upper airway narrows or collapses. Contributors include a crowded or floppy airway, throat muscles that relax too much in sleep and an unstable breathing control system, which specialists describe as high loop gain. In the central type, the brain simply fails to send the signal to inhale. Recent population data suggest purely central cases are rare, about 3.8 percent of diagnosed central apnea, and the two types often overlap.
The cycle is self-interrupting. When the airway blocks, carbon dioxide builds up in the blood, chemical sensors detect it and the brain rouses the sleeper just enough to breathe. The person drifts off again, and the loop repeats. The result is little deep slow-wave sleep and less REM sleep, leaving people exhausted even after a full night in bed. That fatigue raises the risk of car crashes and workplace injuries, and can bring moodiness and poor concentration.
Diagnosis usually involves an overnight lab study. Severity is scored with the apnea-hypopnea index, which counts pauses and shallow-breathing spells longer than 10 seconds per hour of sleep. The American Academy of Sleep Medicine counts an apnea as a drop in airflow of at least 90 percent for 10 seconds or more. The condition is about twice as common in men as women and becomes more likely with age and obesity. In 2017 a US task force judged the evidence insufficient to recommend screening adults without symptoms.
Untreated, it is linked to high blood pressure, heart disease, stroke, atrial fibrillation and type 2 diabetes, and mid-life apnea is associated with a higher chance of Alzheimer's later on. CPAP machines, which push air to hold the airway open, improve outcomes when used properly, but more than half of users struggle to stick with them. In 2017 only 15 percent of potential patients in developed countries used one. Newer weight-loss drugs have produced the first FDA approval of such a medicine for obstructive sleep apnea.
Source: Sleep apnea
