"Using a simple device for eight hours a night to treat sleep apnea can help people with prediabetes improve their blood sugar levels and may reduce the risk of progressing to diabetes according to a new study published online in the April   issue of the American Journal of Respiratory and Critical Care Medicine. About  million Americans have prediabetes a disorder marked by blood sugar levels that are elevated but not sufficiently high to be considered diabetic. Prediabetics are at increased risk for developing diabetes which can damage the eyes kidneys nerves and blood vessels and often leads to cardiovascular disease.  Many people with prediabetes also have untreated sleep apnea although few of them are aware of it. The most widely accepted treatment for sleep apnea is continuous positive airway pressure CPAP a device that blows a constant pressure of air into the lungs through a tube and face mask during the night. This helps people breathe better while they sleep by keeping the upper airway open.  Our study showed that CPAP in patients with prediabetes can lower their risk of progressing to diabetes when CPAP is used for eight hours a full nights sleep said the studys lead author Sushmita Pamidi MD a former fellow at the University of Chicago who is now on the faculty at McGill University in Montreal Canada.  Although eight hours of CPAP per night can be difficult to achieve in reallife our results should provide a strong incentive for anyone with sleep apnea especially prediabetic individuals to improve adherence to their treatment for cardiometabolic risk reduction she said. People with sleep apnea which is common among overweight and obese individuals have repeated episodes where their upper airway closes during sleep. This can disrupt sleep and temporarily lower oxygen levels. It has been associated with an increased risk of cardiovascular diseases such as hypertension and stroke and may decrease their ability to regulate blood sugar levels. This increases the risk of diabetes.  For this study the researchers recruited  middleaged overweight or obese volunteers with prediabetes and sleep apnea. Twothirds of them  were randomly assigned to two weeks of CPAP treatment. The other  received a placebo  a pill containing no medicine  to be taken  minutes before bedtime. They were told the study would compare the two treatments. All participants slept in the sleep laboratory and were closely monitored with allnight sleep recordings during the treatment period. Those assigned to CPAP wore the device for eight hours a night under continuous supervision by a technician. Before and after each treatment period participants glucose metabolism was assessed by oral and intravenous glucosetolerance tests.  The researchers also measured the stress hormone noradrenaline in the blood and continuously monitored blood pressure for  hours at home. All participants were permitted to leave the laboratory during the day and engage in their routine activities.  After two weeks blood sugar control as measured by an oral glucose tolerance test improved for those in the CPAP group compared to the oral placebo group. In addition the ability of insulin to regulate their blood sugar estimated by the intravenous glucose tolerance test was improved in the CPAP group compared to the oral placebo group. The CPAP group had on average  percent lower levels of the stress hormone norepinephrine as well as lower blood pressure than the oral placebo group.  Despite the demonstrated efficacy of lifestyle interventions and the availability of many drug treatments the economic and public health burden of diabetes remains enormous said Esra Tasali MD assistant professor of medicine at the University of Chicago and senior author of the study. Assessment of sleep apnea should be considered in patients at high risk for diabetes and cardiovascular disease since our study shows that treatment of sleep apnea can reduce these risks.  The National Institutes of Health plus the Diabetes Research and Training Center and the Institute for Translational Medicine at the University of Chicago funded this study. Additional authors include Kristen Wroblewski Magdalena Stepien Khalid SharifSidi Jennifer Kilkus and Harry R. Whitmore from the University of Chicago."