Shorter sleep duration is associated with poorer glycemic control in type 2 diabetes patients with untreated sleep-disordered breathing.

Purpose: The purpose of this study is to explore the impact of sleep duration on glycemic control in type 2 diabetes patients with untreated sleep-disordered breathing (SDB).

Methods: Ninety type 2 diabetes patients participated in the study. SDB was diagnosed using an overnight in-home monitoring device (WatchPAT200). Sleep duration was recorded by wrist actigraphy for 7 days. Medical records were reviewed for hemoglobin A1c (HbA1c) values.

Results: Seventy-one patients (78.8 %) were diagnosed with SDB [apnea-hypopnea index (AHI) ≥ 5]. In patients with SDB, there was no significant relationship between AHI and glycemic control. In addition, oxygen desaturation index, minimum oxygen saturation, and time spent below oxygen saturation of 90 % were not significantly correlated with glycemic control. Sleep duration, however, was inversely correlated with HbA1c (r = -0.264, p 0.026). Multiple regression analysis adjusting for age, sex, body mass index, insulin use, diabetes duration, and AHI revealed that sleep duration was significantly associated with HbA1c (p = 0.005). Each hour reduction in sleep duration was associated with a 4.8 % increase in HbA1c of its original value (95 % CI 1.5-8.0).

Conclusion: In type 2 diabetes patients with untreated SDB, shorter sleep duration was independently associated with poorer glycemic control. Sleep duration optimization may lead to improved glycemic control in this population.