Continuous positive airway pressure (CPAP) is a treatment for sleep apnea in which the patient wears a mask to bed that pumps air into the nose to keep the airway open. With sleep apnea, a form of sleep-disordered breathing, breathing stops during sleep. There are two basic types of sleep apnea. In obstructive sleep apnea (OSA), which accounts for about 80% of cases, the airway is blocked, typically due to sagging of the soft tissue in the back of the throat. In central sleep apnea, there is an interruption in the brain signals that initiate breathing. Scientists have long known that sleep apnea is associated with Type 2 diabetes.
Obstructive sleep apnea can cause loud and chronic snoring, sometimes followed by choking or gasping. People with sleep apnea may tend to feel sleepy, irritable, or forgetful during the day.
Sleep apnea is first treated with lifestyle changes, such as avoiding alcohol and sleep-inducing medicines before bed, losing excess weight, and using allergy medicines and nasal sprays as needed. If apnea persists, custom-fit mouthpieces that adjust the lower jaw and tongue can be used to keep airways open.
CPAP is commonly used to treat moderate to severe sleep apnea. A mask is placed over the nose and mouth, or just over the nose. The CPAP machine gently blows a stream of air into the throat, keeping the airway open. CPAP generally alleviates the symptoms of sleep apnea, but its side effects may include a stuffy nose and headaches.
Studies show that people with sleep apnea are 30% more likely to develop Type 2 diabetes than those without sleep apnea. Conversely, people with known diabetes have been shown to have a 23% prevalence of obstructive sleep apnea and a 58% prevalence of sleep-disordered breathing of some kind.
Researchers are still seeking a cause-and-effect relationship between these two conditions. Excess weight is an established risk factor both for OSA and diabetes, but other factors may also play a role. Obstructive sleep apnea may promote insulin resistance and disrupt blood glucose levels, thus raising the risk of Type 2 diabetes. Both conditions can increase the risk of cardiovascular disease.
If sleep apnea can cause diabetes and disrupt blood glucose control, can treating sleep apnea improve blood glucose control in people with Type 2 diabetes? Several studies aimed at answering this question have delivered mixed results, with some showing an effect and others showing none. However, studies have shown that treating sleep apnea with CPAP may improve many markers of cardiovascular disease and may also improve cardiovascular outcomes in patients with heart failure. Health experts recommend treating OSA with CPAP based on its beneficial effects on sleep apnea symptoms and cardiovascular health.
Want to learn more about sleep apnea and diabetes? Read “Sleep Apnea and Type 2 Diabetes,” “Sleep Apnea: A Hidden Enemy in Diabetes,” “Even Moderate Weight Loss Can Improve Sleep Apnea,” and “CPAP May Improve Blood Sugar Levels in People With Sleep Apnea, Type 2 Diabetes”.