Associations between stress symptoms and insomnia in patients with type 2 diabetes: the potential serial mediating roles of anxiety and depressive symptoms

Purpose: This study aimed to explore the potential mediating roles of anxiety and depressive symptoms in the association between stress symptoms and insomnia in adults with type 2 diabetes (T2D). Patients and methods: From January 2021 to March 2024, 484 adults with T2D were included. The Depression Anxiety Stress Scale (DASS-21) and Insomnia Severity Index scale (ISI) were used to assess stress symptoms, anxiety symptoms, depressive symptoms, and insomnia. The PROCESS macro program was used to analyze the potential serial mediation pathways. Results: Of the 484 patients, 85 (17.56%) had insomnia. Insomnia patients had significantly higher age, body mass index (BMI), educational level, duration of illness, complication rate, and levels of anxiety symptoms, depressive symptoms, and stress symptoms than the non-insomnia. Correlation analyses showed that insomnia positively correlated with age, duration of illness, stress symptoms, anxiety symptoms, and depressive symptoms, while negatively correlated with educational level (all P < 0.05). Additionally, these four factors were significantly intercorrelated (all P < 0.05). Mediation analyses showed that stress symptoms were directly associated with insomnia (Effect = 0.264, SE = 0.040, 95% CI = 0.137 - 0.295) and indirectly associated via anxiety symptoms (Effect = 0.094, SE = 0.030, 95% CI = 0.035 - 0.156), depressive symptoms (Effect = 0.055, SE = 0.024, 95% CI = 0.010 - 0.104), and the serial pathway through anxiety and depressive symptoms (Effect = 0.026, SE = 0.013, 95% CI = 0.004 - 0.054). Conclusion: In T2D patients, stress symptoms are directly associated with insomnia, and may also be linked to it through anxiety and depression. This study highlights the need to consider these interrelated factors in clinical management to potentially improve sleep and overall health.