Background: Sleep-disordered breathing (SDB) is a prevalent condition associated with significant comorbidities, including hypertension, obesity, cardiovascular disease, and insulin resistance. It has been previously shown that the severity of insulin resistance is related to the severity of SDB.Methods: Using a 72-hour continuous glucose monitoring system, we studied changes in interstitial glucose levels and measured hemoglobin A1c levels in 25 patients with type 2 diabetes mellitus before and after continuous positive airway pressure (CPAP) treatment for SDB.