Abstract
AIMS/INTRODUCTION: Insomnia is associated with type 2 diabetes mellitus, and results in a low quality of life. There are several known relationships between insomnia and personality. Thus, we clarified the association between some personality traits and insomnia among Japanese type 2 diabetes mellitus patients. MATERIALS AND METHODS: The participants were 504 type 2 diabetes mellitus patients (mean age 63.9 ± 12.5 years). Sleep disturbance and personality traits were evaluated using the Pittsburgh Sleep Quality Index-Japanese version and the Ten-Item Personality Inventory Japanese version, respectively. Lifestyle factors, glycated hemoglobin levels and depressive status of the patients were also included in the analyses. RESULTS: Among the 504 participants with type 2 diabetes mellitus, 154 (30.6%) showed probable insomnia. After adjustment for confounders, being female, living alone, high body mass index and "high neuroticism" were found to be significantly correlated with current insomnia. No other relationships between insomnia and glycated hemoglobin or lifestyle factors, such as smoking, drinking alcohol or exercise frequency, were found. CONCLUSIONS: The prevalence of insomnia in individuals with type 2 diabetes mellitus was high, and the risk factors included some personality factors. Future prospective studies are required to confirm the therapeutic effects of behavioral interventions for insomnia in patients with type 2 diabetes mellitus.