What is obstructive sleep apnoea?
Obstructive sleep apnoea is cessation of airflow at the mouth and nose for more than ten seconds, occurring more than 30 times in a seven hour sleep, caused by airway obstruction. Some surveys suggest that one in four people with diabetes mellitus may have OSA, others that 4 out 5 obese people with diabetes may be affected. There is uncertainty about the rate of OSA in the general population; perhaps 1 in 25 is affected, perhaps more. Obstructive sleep apnoea can be a factor in causing raised blood pressure and in those who suffer one of the severe consequences of high blood pressure, stroke, in whom as many as 75% give a history of having had sleep apnoea.
What causes obstructive sleep apnoea?
Factors linked to OSA include structural abnormalities of the upper airway, being overweight and obese and having a family history of OSA. Scientific studies have shown that in OSA the airway is narrowed and that there is more fat next to the airway in those who are overweight and obese. The muscles supporting the airway may be less good at holding the airway open allowing it to collapse and obstruct.
Does obstructive sleep apnoea matter?
OSA causes snoring interrupted by pauses in breathing, choking and gasping during sleep, restless sleep and excessive daytime sleepiness and perhaps falling asleep at work or while driving a motor vehicle. Quality of life may be seriously impaired by general fatigue, poor concentration, irritability, forgetfulness, morning headaches, depression and sexual dysfunction.