People who have type 2 (adult onset) diabetes and also experience sleep apnea may be able to significantly lower their glucose levels if they treat their breathing disorder, researchers at the University of Illinois at Chicago say.
By reducing glucose levels, diabetics can cut their attendant risks for stroke, heart attack and kidney disease by approximately 6% to 12%. "This is of great clinical significance," says study author Dr. James Herdegen, medical director of the University's Center for Sleep and Ventilatory Disorders.
In the study, 25 type 2 diabetics who had been diagnosed with sleep apnea underwent standard treatment for the condition, called continuous positive airway pressure (CPAP). People using CPAP go to bed wearing a mask over their nose. The mask is attached to a machine that blows air through the bronchial tubes and into the lungs, preventing the back of the throat from closing. Using the mask for a minimum of fours hours each night is needed for effective treatment, says Herdegen.
Most of the patients were male, averaging 50 years old, and had a body mass index (BMI) of 42, which is considered severely obese. Obesity is a known risk factor for diabetes as well as sleep apnea, and diabetics are nine times more likely to have sleep apnea than people who do not have the disease, Herdegen says.
Using the CPAP machine, the participants' overall hemoglobin A1C levels were reduced by 0.5%, which is very similar to the reduction achieved by medication, Herdegen notes.
In addition, their average glucose levels one hour after eating-a key measurement when monitoring diabetes--dropped from 190 mg/dl to 135 mg/dl. Glucose levels that are between 140 and 160 mg/dl are considered manageable for diabetic patients. In people who do not have diabetes, levels between 70 and 120 mg/dl are considered healthy.
The strong results from this study indicate the need for a larger study to measure these effects, Herdegen says, but also suggest that screening for sleep apnea should be a regular part of treatment for type 2 diabetics.
"This study illustrates the fact that type 2 diabetics with a risk for sleep apnea should be screened, because we have a very effective treatment that will help them feel better, and improve their diabetes management," he says.
"This is a -very good paper, and takes the known research about diabetes and sleep apnea one step further," says Dr. Meir Kryger, the director of the Sleep Disorders Center at St. Boniface Hospital in Winnipeg, Manitoba, Canada, and author of A Woman's Guide to Sleep Disorders.
It has been established that sleep apnea impairs the body's ability to properly deal with glucose, but this work shows that treating sleep apnea improves the patient's glucose metabolism, he adds.
Herdegen notes that because the standard treatment for sleep apnea is complicated, compliance is uneven-approximately 50% to 60%. But, he says, the quality of the machines is improving and the masks are becoming more comfortable. And, he adds, for diabetics who have sleep apnea, "the treatment brings not only short-term results but long-term benefits."