The influence of vascular risk factors on the survival rate of patients with dementia with Lewy bodies and Alzheimer disease

Abstract

Background and purpose

The aim of this study was to determine whether dementia with Lewy bodies (DLB) progresses more rapidly than Alzheimer disease (AD) and to compare survival after dementia onset and mortality in both dementia groups.

Material and methods

A medical records analysis of AD (n = 183) and DLB (n = 51) patients was performed to determine age at onset of symptoms, the date of first presentation to the psychiatric services, dementia severity at diagnosis (MMSE score), and mean disease duration before diagnosis. Categorical data regarding vascular risk factors were collected. Projected decline rate (MMSE/year), survival rate after the diagnosis of dementia, mean survival time after diagnosis and mortality rate were calculated and compared between DLB and AD groups.

Results

The comparison of clinical and demographic parameters revealed no significant differences between groups, apart from a more pronounced decline rate in the DLB group. Diabetes, and to a lesser extent hypertension, influenced survival in AD, but not in DLB subjects. Overall, however, the difference in mortality rates and survival time between DLB and AD subjects cannot be attributed to the presence of any vascular risk factor analysed. DLB, independently of the presence of vascular risk factors, seems to be a more aggressive disorder than AD, when mortality and survival time are taken into account.

Conclusions

More rapid progression of cognitive decline and shorter duration of dementia were found in DLB in this naturalistic study. The findings may have important implications for the management and treatment of DLB and should be confirmed in prospective studies.