CPAP Therapy of Obstructive Sleep Apnea in Type 2 Diabetics Improves Glycemic Control During Sleep

Abstract

SciEnTific invESTigATiOnSBackground: Type 2 diabetes and obstructive sleep apnea (OSA) are frequently comorbid conditions. OSA is associated with increased insulin resistance, but studies of continuous positive airway pressure (CPAP) have shown inconsistent effects on glycemic control. However, endpoints such as hemoglobin A1c and insulin sensitivity might not reflect short-term changes in glycemic control during sleep. Methods: We used a continuous glucose-monitoring system to measure interstitial glucose every 5 minutes during polysomnography in 20 patients with type 2 diabetes and newly diagnosed OSA. The measurements were repeated after an average of 41 days of CPAP (range 26-96 days). All patients were on a stable diet and medications. Each 30-second epoch of the polysomnogram was matched with a continu-second epoch of the polysomnogram was matched with a continu-epoch of the polysomnogram was matched with a continuous glucose-monitoring system reading, and the sleeping glucose level was calculated as the average for all epochs scored as sleeping. Results: The mean sleeping glucose decreased from untreated (122.0 ± 61.7 mg/dL) to treated (102.9 ± 39.4 mg/dL; p = 0.03 by Wilcoxon paired rank test). The sleeping glucose was more stable after treatment, with the median SD decreasing from 20.0 to 13.0 mg/dL (p = 0.005) and the mean difference between maximum and minimum values decreasing from 88 to 57 mg/dL (p = 0.003). The change in the mean hemoglobin A1c from 7.1% to 7.2% was not significant. conclusions: Our study is limited by the lack of a control group, but the results suggest that sleeping glucose levels decrease and are more stable after patients with type 2 diabetes and OSA are treated with CPAP.

Risk for Obstructive Sleep Apnea among People with Diabetes

“…However, the level of control is far from optimal level as found in a recent study 49 . While some studies found that treatment of OSA improves A1C, the results are inconsistent 7,29,50 .…”

“…Furthermore, OSA is commonly associated with known diabetic complications 4,[9][10][11]25,26 . Lastly, screening and initiation of treatment may contribute to prevention and improved control of co-morbid conditions 16,[27][28][29] .…”

Disorders of glucose metabolism and insulin resistance in patients with obstructive sleep apnoea syndrome

“…Moreover, it has been proposed that the recovery of breathing disturbances during sleep can improve several markers of DGM and insulin resistance, such as glycated haemoglobin, fasting glucose and insulin (29). Sleeping and nocturnal hyperglycaemia were reduced during CPAP treatment in the group of mostly obese type 2 DM with moderate to severe, mostly severe OSAS (30). Another study determined that CPAP therapy improved both excessive daytime sleepiness and insulin resistance in patients with OSAS having excessive daytime sleepiness (7).…”

Effects of Positive Airway Pressure Treatment on Clinical Measures of Hypertension and Type 2 Diabetes

“…2 The results of experimental studies evaluating effects of OSA treatment in hypertension reveal modest benefi ts, 3,4 and the data regarding improvement in glucose homeostasis in type 2 diabetics from small clinical trials are inconsistent. 5,6 This discrepancy is partly due to the size and type of cohorts examined or the specifi c outcomes assessed. 7 Several studies examined populations with differential baseline characteristics (presence or absence of preexisting hypertension/diabetes) or variable OSA disease severity.…”