Sleep Quality, Glycemic Control, and Daytime Dysfunction in Type 2 Diabetes

Background and Objectives: Adults diagnosed with type 2 diabetes mellitus (T2DM) frequently exhibit diminished sleep quality, which is affected by their glycemic control. Both poor sleep and inadequate glycemic management increase the risk of complications worldwide. However, the relationship between sleep quality, daytime dysfunction, and glycemic control in adults with T2DM is not well understood. To address this gap, this study aimed to examine the association between overall sleep quality, including daytime dysfunction, and glycemic control in adults with T2DM. Materials and Methods: A hospital-based cross-sectional study included 200 T2DM patients (103 females, 97 males) from January 2019 to January 2020. The Pittsburgh Sleep Quality Index (PSQI) was administered to each participant to assess sleep quality, including daytime dysfunction. Glycemic control was assessed by measuring hemoglobin A1c (HbA1c) and fasting blood glucose (FBG) levels. The associations among sleep quality, daytime dysfunction, and glycemic metrics were examined utilizing both conventional statistical methods and Bayesian analytical approaches. Results: A total of 32% of patients had poor sleep quality (PSQI > 5), and 43.5% reported daytime dysfunction. Higher HbA1c and fasting blood glucose were each correlated with longer sleep-onset latency and greater daytime dysfunction. In multivariable analyses, higher HbA1c and longer sleep-onset latency were independently associated with poor sleep quality (generalized linear model, R² = 0.602), whereas higher fasting blood glucose and longer sleep-onset latency were associated with greater daytime dysfunction severity (R² = 0.378). Conclusions: Sleep quality and delay in falling asleep are interdependent with impaired glycemic control and daytime dysfunction in T2DM. Future randomized trials targeting sleep-onset latency are warranted to determine causal effects on glycemic outcomes.