A sleep disorder in which breathing stops for 10 seconds or more during sleep, sometimes as often as 300 times a night. Research suggests that diabetes can cause — and be caused by — sleep apnea.
People with sleep apnea are often unaware that they stop breathing at night, but their bed partners may notice their restless sleep, snoring, and gasping for breath. The person with sleep apnea may be excessively sleepy during the day, sometimes falling asleep at work or while driving. He may also suffer from headaches, fatigue, difficulty concentrating, irritability, forgetfulness, moodiness, and anxiety. Untreated, sleep apnea may increase the risk of high blood pressure and cardiac problems, possibly because the heart must pump harder every time blood oxygen levels drop.
There are two basic types of sleep apnea. Obstructive sleep apnea, the most common form, is the cessation of breathing due to a blockage of the airway, often when the soft tissue in the back of the throat sags during sleep. In central sleep apnea, the brain fails to send the necessary messages to the muscles to initiate breathing. Once the levels of oxygen in the blood go low enough, the sleeper usually awakens abruptly and starts breathing again. (In contrast to obstructive sleep apnea, people with central sleep apnea are usually aware that they have woken during the night.) It is also possible to have mixed sleep apnea, which is a combination of the two other forms.
Studies have shown numerous associations between sleep-disordered breathing (including sleep apnea) and diabetes. A number of studies suggest that sleep deprivation can impair the body’s ability to process glucose, leading to high blood glucose levels. Other studies have shown an association between sleep apnea and insulin resistance, a condition in which muscle, fat, and liver cells do not use insulin properly. Insulin resistance is one of the main underlying problems in Type 2 diabetes.
Some studies also indicate that diabetic autonomic neuropathy, or damage to the nerves that control vital automatic functions such as heartbeat and breathing, may be associated with breathing problems and may even cause central sleep apnea. In addition, obesity is a risk factor both for Type 2 diabetes and obstructive sleep apnea.
There are a number of potential treatments for sleep apnea, including lifestyle measures. For obese people, losing even 10% of body weight can greatly reduce the frequency of nightly sleep apnea episodes. Avoiding tobacco, alcohol, and sedatives before bed can also help, because these can relax the muscles in the back of the throat. Avoiding sleeping on one’s back can somewhat alleviate the problem: Some people attach a tennis ball or similar object to the back of their pajama top to prevent themselves from sleeping on their back.
If these measures don’t work, many serious cases of obstructive sleep apnea can be relieved by a therapy called continuous positive airway pressure, or CPAP. The person straps a mask over his nose before going to bed. The mask is connected to a small machine that pumps air into the mask to keep the airway open.