Sleep Disorders Sleep Apnea

Masked Marvels: Why Treating Sleep Apnea Helps Diabetes

Treatment for diabetes usually involves insulin injections or pills to control blood sugar levels. But a study shows that for some people with diabetes, a therapy that helps treat a serious, but common, sleep disorder can also help keep your blood sugar levels in check.

The study, published on February 28 in the Archives of Internal Medicine, found that continuous positive airway pressure (CPAP), a treatment for sleep apnea, improves insulin resistance and, as a result, blood sugar levels in patients who have both sleep apnea and type 2 diabetes.

"There clearly appears to be an association with sleep apnea and diabetes," said study author James Herdegen, MD, an associate professor of medicine at the University of Illinois at Chicago. "There are [overlapping] risk factors for both conditions. For example, if you're obese, you'll be at risk for both sleep apnea and diabetes."

Sleep apnea is a common, yet under-diagnosed, sleep disorder in which a person's airway becomes blocked during sleep, preventing air from reaching the lungs and oxygen from getting to the blood. Breathing may be irregular or even stop briefly, resulting in snoring, frequent wakings or a restless sleep as the person moves in and out of deep sleep several times during the night. Untreated, sleep apnea can lead to high blood pressure, heart disease and stroke. It's also a major cause of daytime sleepiness that can result in auto accidents. It is nearly 100 percent effective in curing sleep apnea and associated snoring when used regularly. However, many people have trouble sticking with CPAP, complaining about the discomfort or inconvenience of the treatment.

A CPAP machine treats sleep apnea by forcing air up through a person's nose via a silicon mask during sleep, keeping the airway open.

While the connection between the two illnesses are unclear, Dr. Herdegen suspects that getting a better night's sleep may help the body maintain a healthy blood sugar level by controlling hormones and preventing oxidative stress, which is cell damage caused by free radicals; this can occur in people with sleep apnea when the body's tissues don't get the oxygen they need.

In the study, which looked at 25 people with both sleep apnea and type 2 diabetes, each person received CPAP treatment for at least four hours each night for three months. The participants' blood sugar levels and blood hemoglobin A1C levels, a more accurate predictor of diabetes control, were monitored throughout the study. After three months, those that adhered to the treatment showed a reduction in both measurements, reflecting an improvement in their condition.

The effects of treating sleep apnea may also improve the symptoms of diabetes in other ways.

"Clearly CPAP, through improving sleep quality and restfulness, may also improve energy levels and improve someone's ability to have a more active lifestyle," Dr. Hedergen said.

Dr. Hedergen advised all people with type 2 diabetes to undergo a simple screening questionnaire for sleep apnea because they are at such a high risk for this disorder. You'll be asked questions about daytime sleepiness, frequent nighttime waking, snoring and other symptoms of sleep apnea. If your questionnaire response suggests that you may have sleep apnea, you should undergo a sleep study to determine if you truly have this disorder.

"If you're a diabetic and overweight with some simple risks factors for sleep apnea, get screened," he said, "because it can have a potential impact not only on how you feel in general, but also on your underlying diabetes."