The role of sleep disturbance and depression in patients with type 2 diabetes

Abstract

The importance of sleep disturbance and depression in patients with type 2 diabetes is unclear. Our objective was to evaluate their effects on the quality of life (QOL) of patients with type 2 diabetes. For the study, 270 patients were recruited from the Shiga Prospective Observational Follow-up Study for Diabetic Complications. Depressive symptoms, sleep disturbance, and QOL were assessed by use of the Zung Self-Rating Depression Scale (SDS), the Pittsburgh Sleep Quality Index (PSQI), and SF-8, respectively, after evaluation of their metabolic control and complications. Furthermore, 141 patients were recruited to repeat the same study after 6–12 (mean 7.3) months. Significant correlations were found among sleep disturbance, depression, and QOL in patients with type 2 diabetes. Patients undergoing insulin therapy had significantly higher SDS scores, meaning more depressive symptoms, than those not undergoing insulin therapy. Patients with painful neuropathy had higher PSQI and SDS scores and lower physical component of the QOL score than patients without painful neuropathy. In the follow-up observation it was found that the presence of neuropathy and elevated HbA1c level were predictors of increasing PSQI score and SDS score, respectively. It was found that the presence of painful neuropathy was a risk factor for sleep disturbance for type 2 diabetic patients. Sleep disturbance and depressive symptoms correlated significantly with the QOL scores of patients with type 2 diabetes, suggesting the importance of these indices for better management of diabetic patients.