The influence of vascular risk factors on cognitive decline in patients with Alzheimer's Disease

Introduction

The influence of vascular risk factors (VRFs) on the rate of cognitive decline in patients with established dementia is unclear. This study aims to examine the association between VRFs and the rate of cognitive decline in patients with Alzheimer's disease (AD).

Methods

Data were obtained from patients visiting a memory clinic between 2004 and 2012. VRFs were determined at baseline and included hypertension, hypercholesterolemia, diabetes mellitus, overweight and smoking. Continuous values of blood pressure, total cholesterol, glucose level and body mass index were also obtained. Mini-Mental State Exam (MMSE) scores were obtained at baseline and during follow-up visits. The association between VRFs and the annual change in MMSE scores was analysed with a multivariable linear mixed model adjusted for age, sex and the aforementioned VRFs.

Results

From 174 patients (mean age 78.3 years), with a follow-up time up to 5.8 years (mean 1.1 year), in total 447 MMSE scores were obtained. The multivariable analyses showed an association between age as well as systolic blood pressure and a decline in annual rates of change in MMSE scores of −0.05 (95% confidence interval (CI): −0.09 to 0.00) and −0.01 (CI: −0.03 to 0.00), respectively. For all other VRFs, including sex, patients did not show a significant difference.

Conclusion

This study did not find an association between preventable vascular risk factors and cognitive decline in patients with AD, except for systolic blood pressure. As the association between systolic blood pressure and decline in MMSE was small, clinical relevance may be limited.