Association between vascular comorbidity and progression of Alzheimer\u2019s disease: a two-year observational study in Norwegian memory clinics

Rannveig Sakshaug Eldholm,Maria Lage Barca,Geir Selbaek,Lena Cavallin,Eva Skovlund,Ingvild Saltvedt,Karin Persson,Knut Engedal,Anne-Brita Knapskog

doi:10.1186/s12877-018-0813-4

Abstract

BackgroundVascular risk factors increase the risk of Alzheimer’s disease (AD), but there is limited evidence on whether comorbid vascular conditions and risk factors have an impact on disease progression. The aim of this study was to examine the association between vascular disease and vascular risk factors and progression of AD.MethodsIn a longitudinal observational study in three Norwegian memory clinics, 282 AD patients (mean age 73.3 years, 54% female) were followed for mean 24 (16–37) months. Vascular risk factors and vascular diseases were registered at baseline, and the vascular burden was estimated by the Framingham Stroke Risk Profile (FSRP). Cerebral medical resonance images (MRIs) were assessed for white matter hyperintensities (WMH), lacunar and cortical infarcts. The associations between vascular comorbidity and progression of dementia as measured by annual change in Clinical Dementia Rating Sum of Boxes (CDR-SB) scores were analysed by multiple regression analyses, adjusted for age and sex.ResultsHypertension occurred in 83%, hypercholesterolemia in 53%, diabetes in 9%, 41% were overweight, and 10% were smokers. One third had a history of vascular disease; 16% had heart disease and 15% had experienced a cerebrovascular event. MRI showed lacunar infarcts in 16%, WMH with Fazekas score 2 in 26%, and Fazekas score 3 in 33%. Neither the vascular risk factors and diseases, the FSRP score, nor cerebrovascular disease was associated with disease progression in AD.ConclusionsAlthough vascular risk factors and vascular diseases were prevalent, no impact on the progression of AD after 2 years was shown.

Highlights

Vascular risk factors increase the risk of Alzheimer’s disease (AD), but there is limited evidence on whether comorbid vascular conditions and risk factors have an impact on disease progression
It is not known if, or to what extent, the presence of vascular risk factors in late life leads to accumulation of AD pathology, as a recent study found no association between late-life vascular risk factors and late-life brain amyloid deposition [2]
* The Framingham Stroke Risk Profiles were not adjusted for age and sex hypercholesterolemia or diabetes, but no association with the progression of AD was found. In this descriptive cohort study in memory clinic patients with AD, we examined whether vascular risk factors, cardiovascular and cerebrovascular diseases or total vascular burden were of importance for the progression of AD

Summary

Introduction

Vascular risk factors increase the risk of Alzheimer’s disease (AD), but there is limited evidence on whether comorbid vascular conditions and risk factors have an impact on disease progression. Longitudinal studies have established a strong link between vascular risk factors in midlife, such as hypertension, hypercholesterolemia, diabetes mellitus, smoking and being overweight, and development of Alzheimer’s disease (AD) decades later [1]. It is suggested that AD pathology accumulates for many years or even decades before symptoms evolve [8] It is not known if, or to what extent, the presence of vascular risk factors in late life leads to accumulation of AD pathology, as a recent study found no association between late-life vascular risk factors and late-life brain amyloid deposition [2]. As the association between midlife vascular risk factors and incident AD is well established, it could be hypothesised that these risk factors affect progression after symptoms evolve. The literature is conflicting regarding which vascular risk factors could be of significance for progression, and even whether these factors seem to ameliorate or aggravate the disease course

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