Cui Ying Wei,1,* Zhong Ming He,2,* Han Yan,3 Jing Li,3 Pei An,3 Long Zhao,3 Li Nong Ji,4 Zhan Cheng Gao,3 Xiao Song Dong,3 Fang Han3 1Department of Endocrinology, First Affiliated Hospital, Baotou Medical College, Baotou, Inner Mongolia, People’s Republic of China; 2Department of Pulmonary Medicine, Karamay Central Hospital, Karamay, Xinjiang, People’s Republic of China; 3Department of Respiratory and Critical Care Medicine, Peking University People’s Hospital, Beijing, People’s Republic of China; 4Department of Endocrinology, Peking University People’s Hospital, Beijing, People’s Republic of China*These authors contributed equally to this workCorrespondence: Xiao Song DongDepartment of Respiratory and Critical Care Medicine, Peking University People’s Hospital, Beijing, People’s Republic of ChinaTel/Fax +86-10-88324207Email dongxiaosong@pkuph.edu.cnPurpose: The study aimed at assessing glucose control measured with a continuous glucose monitoring system (CGMS) before and after short-term continuous positive airway pressure (CPAP).Materials and Methods: Twenty-four type 2 diabetic patients (T2DM) with Obstructive sleep apnea syndrome (OSAS) (mean age 55.0 ± 9.0 years; BMI 29.5 ± 5.2 kg/m2) were admitted and kept under diet control for 2 days, then underwent 2 overnight polysomnographies: a diagnostic study and one with CPAP titration. Then they were treated by CPAP during sleep for the following three nights. Participants were divided into subgroup D (only diet control) and subgroup M (with DM medication). CGMS was utilized over the last five days. Glucose control was also assessed with plasma insulin and a clinical measure of insulin resistance (HOMA-IR) index.Results: The mean (±SD) apnea-hypopnea index (AHI) at diagnostic polysomnography was 51.2 ± 22.4 (range 10– 88) events/h. CPAP treatment in the subjects with OSAS resulted in the index of oxygenation desaturations being reduced from 33.3 ± 20.1 to 1.1 ± 1.6 (P =0.00). CGMS showed mean 24-hours glucose values significantly lower after CPAP treatment than at baseline in both subgroups (7.97± 1.31 vs 7.52± 0.94, P=0.033 in subgroup D; and 7.72± 1.51 vs 7.17± 1.21, P=0.05 in subgroup M), as the fasting plasma insulin levels and HOMA-IR were also decreased significantly after CPAP treatment (13.0 ± 7.5μU/mL vs 10.8 ± 5.4μU/mL, P=0.044; and 4.2 ± 2.2 vs 3.1± 1.7, P=0.003, respectively). Standard deviation (SD) and mean amplitude of glucose excursions (MAGE) were also decreased in the subgroup D (1.91 ± 1.10 vs 1.61 ± 1.20, P=0.014; 1.26 ± 1.13 vs 1.01 ± 0.98, P=0.008, respectively) only.Conclusion: Short-term CPAP treatment in OSAS with type 2 diabetic patients is accompanied by a decrease in blood glucose level and improved insulin sensitivity. Glucose variability was reduced but only in the patients with diet control.Keywords: type 2 diabetes mellitus, obstructive sleep apnea syndrome, continuous positive airway pressure, continuous glucose monitoring system, glucose variability, HOMA-IR
