Prevalence, symptomatic features, and factors associated with sleep disturbance/insomnia in Japanese patients with type-2 diabetes

Purpose: To clarify the prevalence and symptomatic characteristics of sleep disturbance/insomnia among type-2 diabetes mellitus (DM) Japanese patients. Methods: A cross-sectional survey of Japanese patients with the disorder was conducted. Participants consisted of 622 type-2 DM patients (mean 56.1 +/- 9.56 years) and 622 sex-and agematched controls. Participants' scores in the Japanese version of the Pittsburgh Sleep Quality Index (PSQI-J), the Japanese version of the 12-item Center for Epidemiologic Studies Depression Scale (CES-D), the Medical Outcomes Study 8-item Short Form Health Survey (SF-8), and the glycated hemoglobin A1c (HbA1c) of type-2 DM patients were analyzed. Results: There were 253 poor sleepers (43.9%) in the type-2 DM group as a result of dichotomization with the PSQI-J cutoff total score of 5.5. The type-2 DM group recorded a higher mean PSQI-J total score (P<0.01) and manifested poorer sleep maintenance. Poor sleepers in both groups had lower mental component summary from SF-8 (MCS), physical component summary from SF-8 (PCS), and CES-D than good sleepers, and good sleepers in both groups had higher MCS, PCS, and CES-D than poor sleepers. Higher body mass index, presence of smoking habit, and living alone were significantly associated with sleep disturbance/insomnia symptoms, but HbA1c was not associated with sleep disturbance/insomnia in the type-2 DM group. Conclusion: Individuals affected with type-2 DM are likely to experience sleep problems, characterized by disturbance in sleep maintenance. Sleep disturbance/insomnia symptoms in DM patients might considerably reduce health-related quality of life.