Relationship Between Depression and Decreased Activity Level and Cognitive Impairment in Patients with Diabetes Mellitus Type 2 and/or Atrial Fibrillation

<b>Background:</b> The interdependence between type 2 diabetes mellitus (DM-2), atrial fibrillation (AF), and cognitive decline (CD)/dementia is a debated topic. In this study, we highlighted the influence of DM-2 and FA individually and in association on the severity of CD/dementia. <b>Methods:</b> This study comprises 248 patients with very high cardiovascular risk (VHCVR) according to Systematic Coronary Risk Evaluation (SCORE2), of whom 184 had DM-2 and/or AF, and 64 were age-matched controls (without DM-2/AF), admitted to the Municipal Hospital Timisoara. <b>Results:</b> Mini-Mental-State-Examination (MMSE), Montreal Cognitive Assessment (MoCA), Activities of Daily Living Score (ADL), and Instrumental Activities of Daily Living Score (IADL) were significantly decreased, and Geriatric Depression Scale (GDS-15) increased in patients with DM-2 and AF in comparison to controls (<i>p</i> < 0.05), with the subjects with DM-2 and AF having more severe CD compared to those with only one of these two pathologies. The logistic regression model showed that the risk of CD (MMSE < 27) or dementia (MMSE < 24) increased significantly in patients with DM-2 and/or AF depending on the SCORE2 values, ADL, and GDS-15. In DM-2 and/or AF patients, an increase of 1% in SCORE2 was associated with an elevation of 2.40% in the odds of CD and of 4.30% of dementia. In these patients, depression (GDS score) increased the risk of CD by 36.3%, and if ADL improved, the risk of CD decreased by 44.0%. <b>Conclusions:</b> Our findings suggest a direct association between CD, DM-2, and AF with SCORE2, cognitive parameters, ADL, and depression. In patients with DM-2 and/or AF, it is important to identify subclinical CD to prevent the evolution to dementia.