Sleep Quality and Depression: Does Diabetes Mellitus Affect the Association in Older Patients?

Background: Sleep quality and depression in late adulthood, especially in patients with diabetes mellitus (DM), may affect quality of life and active ageing. Objectives: This research aimed to examine the association between sleep quality, depression, and DM in older adults. Methods: This case-control study is performed on people aged 60 years and over living in Amirkola, north of Iran. Participants were divided into two equal groups randomly, based on DM's status. Sleep quality was assessed using the Pittsburgh sleep quality index, and depression was evaluated using the Geriatric Depression Scale. Results: Totally, 800 older adults were examined. The results showed that in both groups, with or without DM, people with depression had poorer sleep quality (P < 0.001). Logistic regression analysis revealed the significant effect of female gender (OR = 2.36; 95% CI: 1.70 - 3.27) and depression (OR = 1.85; 95% CI: 1.37 - 2.51) on sleep quality of older adults (P < 0.001). Conclusions: Older people with or without diabetes were more likely to present poor sleep if they had depression, and DM didn't significantly affect sleep quality.