Inflammatory markers and the risk of dementia and Alzheimer's disease: A meta-analysis

Introduction

Inflammatory markers are often elevated in patients with dementia, including Alzheimer's disease (AD). However, it remains unclear whether inflammatory markers are associated with the risk of developing dementia.

Methods

We searched PubMed, Embase, and Cochrane library for prospective population-based studies reporting associations between inflammatory markers and all-cause dementia or AD. We used random effects meta-analyses to obtain pooled hazard ratios (HRs) and 95% confidence intervals of inflammatory markers (highest vs. lowest quantile) for all-cause dementia and AD.

Results

Fifteen articles from 13 studies in six countries reported data that could be meta-analyzed. C-reactive protein (HR = 1.37 1.05; 1.78]), interleukin-6 (HR = 1.40 1.13; 1.73]), α1-antichymotrypsin (HR = 1.54 1.14; 2.80]), lipoprotein-associated phospholipase A2 activity (HR = 1.40 1.03; 1.90]), and fibrinogen were each associated with all-cause dementia, but neither was significantly associated with AD.

Discussion

Several inflammatory markers are associated with an increased risk of all-cause dementia; however, these markers are not specific for AD. Whether inflammatory markers closely involved in AD pathology are associated with the risk of AD remains to be elucidated.