Depression as a Risk Factor for Dementia in older people with type 2 Diabetes and the Mediating Effect of Inflammation

Abstract

Objective: The aim of this study is to detect the relation between depression and dementia in patients with type 2 diabetes. Methods: Clinically diagnosed Type 2 diabetes underwent screening for depression using Beck's Depression Inventory scale and subsequent risk of dementia defined using medical reports, prescription data and death certificates. The mediating act of inflammation systemically was measured by assessing four inflammatory markers (C reactive protein, ESR and Fibrinogen). Results: The study was conducted on 102 diabetic type 2 patients, included 48 males and 54 females. Patients divided into 12 (11.7%) patients with depression and 90 (88.3%) patients without depression (mean age 61±8.6 and 60.9±9.2 respectively). Mean BMI in depressive patients was 33.5 ± 9.3 and was 31.9 ± 8.9 in non-depressive cases (P value 0.01). There were no significant differences in patients with and without depression regarding the presence of hypertension, hyperlipidemia and smoking as risk factors of dementia. Patients with depression had significant impaired cognition and the total MoCA scores were significantly lower than those of patients without depression (23.21 ± 3.48 vs 26.34 ± 3.78, P <0.05). Complication of diabetes in patients with depression as neuropathy was significant (P value 0.005). Other complications as diabetic retinopathy and nephropathy were non-significant. Inflammatory markers levels in patients with depressive symptoms were significantly higher (P value < 0.01). Conclusion: In patients with type 2 diabetes, there is an important association between dementia and depression. Systemic inflammation had a significant role in the relation between depression and dementia.