How rapid eye movement sleep in OSA patients affects type 2 diabetic patients….
Obstructive sleep apnea (OSA) is considered to be a risk factor forf type 2 diabetes. Increased bodyweight is believed to be associated with an increased number of sleep disturbances, particularly OSA. OSA can be defined as a treatable, chronic sleep disorder characterized by partial or complete obstruction of the upper airway.
Previous studies tested the severity of OSA in type 2 diabetic patients and found a robust association between the presence and severity of OSA and insulin resistance in nondiabetic patients. Two larger studies have shown a major association between increasing OSA severity and increasing hemoglobin A1c in patients with type 2 diabetes. The previously mentioned studies may suggest that an effective nonpharmacological strategy for OSA may be as simple as controlling glucose levels.
This study compared the contributions of rapid eye movement (REM) versus non-REM (NREM) OSA to glycemic control in a large cohort of adults with type 2 diabetes. This study recruited participants from endocrinology clinics near the University of Chicago. The criteria included: diagnosis of type 2 diabetes by a physician, subjects on a stable diabetic regimen for at least 3 months and subjects with stable cardiopulmonary conditions. All subjects involved in the study underwent a standard 75-g oral glucose tolerance test; 141 participants qualified for this study but 10 subjects refused to take the glucose tolerance test. OSA was present in 85.2% of the participants; 29.6% of those subjects had severe OSA. Data from this study illustrated the severity of OSA to be greater in REM sleep than in NREM sleep. REM sleep was associated with increased sympathetic activation and reduced vagal tone. Most endocrine organs involved in glucose regulation are sensitive to changes in sympathovagal balance. The study concluded that despite the shorter duration of REM sleep, exposure to the consequences of OSA [hypoxemia] were greater during REM sleep than NREM sleep. The study did not determine if hyperglycemia played a role in severity of REM OSA.
In conclusion, this study found that obstructive events during REM sleep are adversely associated with glucose metabolism. The study further concluded that REM sleep is dominant during the latter part of the sleep period and that REM-related OSA may often remain untreated with four hours of continuous positive airway pressure (CPAP) use.
This study does provoke interest in type 2 diabetic patients with OSA as a main risk factor or comorbidity. Further studies are needed to determine hyperglycemic association with sleep apneas.
Grimaldi D, Beccuti G, Touma C, et al. Association of Obstructive Sleep Apnea in rapid eye movement sleep with reduced glycemic control in type 2 diabetes: therapeutic interchange. Diabetes Care. 2014 Feb.