The relationship between obstructive sleep apnea and insulin resistance in patients with type 2 diabetes mellitus: a cross-sectional observational study

Background: Increasing evidence suggests obstructive sleep apnea (OSA) is an independent risk factor for type 2 diabetes. Insulin resistance is the primary mechanism in the early stage of type 2 diabetes. The aim of this study was to assess the prevalence of OSA among patients with type 2 diabetes mellitus and to examine the association between OSA severity and insulin resistance. Methods: This study adopted a cross-sectional observational design. We enrolled patients hospitalized for poorly controlled type 2 diabetes mellitus from the Endocrine Department of Beijing Chao-Yang Hospital and recorded their demographic and clinical data in an electronic case report form. Polysomnography (PSG) monitoring was performed for all the subjects. According to the apnea hypopnea index (AHI), the subjects were classified into the following three groups: the control group, AHI