Association of Diabetes Mellitus with Incident Dementia in Patients with Atrial Fibrillation in the Atherosclerosis Risk in Communities Cohort Open Access

Jiayaspathi, Ashwini (Spring 2020)

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Patients with atrial fibrillation (AF) are at increased risk of dementia. Whether diabetes mellitus (DM) is a risk factor for incident dementia in AF has not been explored. This information can enable us to take the necessary steps to prevent dementia in this population.


To determine the association between presence of diabetes mellitus at time of AF diagnosis with the risk of incident dementia.


We identified individuals with an incident diagnosis of AF in the Atherosclerosis Risk in Communities (ARIC) cohort (1987-2017) and determined their diabetes status, blood glucose and HbA1c levels at the time of diagnosis. The primary outcome of incident dementia was defined using information from cognitive assessments, informant interviews and hospitalization surveillance. We calculated hazard ratios (HRS) and 95% confidence intervals (CIS) of incident dementia for each level of exposure using Cox models and adjusting for potential confounders.


We analyzed 3,020 patients with AF in the ARIC cohort of which 808 had diabetes and 530 had incident dementia after a mean follow-up of 5.3 years. After multivariable adjustment, AF patients with diabetes had higher rates of dementia than non-diabetics (HR 1.45, 95%CI 1.16, 1.80). Diabetes status, but not fasting blood glucose, was associated with the rates of dementia: compared to non-diabetics with blood glucose <96, the HR and 95%CI of dementia were 0.99 (0.77, 1.29) for non-diabetics with blood glucose between 96 to <105mg/dl, 0.97 (0.74, 1.27) for non-diabetics with blood glucose ≥105mg/dl, 1.74 (1.20, 2.52) for diabetics with blood glucose <131 mg/dl, 1.30 (0.91, 1.86) for diabetics with blood glucose between 131 to < 171mg/dl) and 1.31 (0.87, 1.97) for Diabetics with blood glucose ≥171mg/dl. An increase of 1 unit of HbA1c was associated with a HR 1.29, 95%CI 0.97, 1.71 of dementia.


Patients with AF with diabetes mellitus experienced higher rates of incident dementia compared to non-diabetics. No obvious difference was observed in the rates of dementia upon classifying the patients using blood glucose, independently of their diabetes status.

Table of Contents

Introduction 1

Methods 2

Statistical Analysis  6

Results 8

Discussion 11

Conclusion 14

References 16

Figure Legends 20

Tables 21

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