Association of C-reactive protein with mild cognitive impairment
Abstract
Background
Inflammation is proposed to play a role in the development of Alzheimer's disease, and may also be involved in the pathogenesis of mild cognitive impairment (MCI). This study examined the association of inflammatory markers in serum or plasma with prevalent MCI and MCI subtypes in a population-based sample.
Methods
Olmsted County, MN, residents aged 70–89 years on October 1, 2004, were evaluated using the Clinical Dementia Rating Scale, a neurological evaluation, and neuropsychological testing. Information ascertained for each participant was reviewed by an expert panel of neuropsychologists, physicians, and nurses, and a diagnosis of normal cognition, MCI, or dementia was made by consensus. C-reactive protein (CRP), interleukin-6 (IL-6), tumor necrosis alpha (TNFα), and adiponectin were measured at baseline.
Results
Among 313 subjects with MCI and 1570 cognitively normal subjects, a CRP level in the upper quartile (>3.3 mg/L) was significantly associated with MCI (odds ratio [OR], 1.42; 95% confidence interval [CI], 1.00–2.01) and with nonamnestic MCI (OR, 2.05; 95% CI, 1.12–3.78) after adjusting for age, sex, and years of education. However, there was no association with amnestic MCI (OR, 1.21; 95% CI, 0.81–1.82). No association was observed with the other inflammatory markers.
Conclusions
Plasma CRP is associated with prevalent MCI and with nonamnestic MCI in elderly, nondemented persons in a population-based setting. These findings suggest the involvement of inflammation in the pathogenesis of MCI.
This study was supported by the National Institute on Aging (grants U01-AG06786, K01-AG028573, and P50-AG16574), the National Institute of Mental Health (grant K01-MH68351), and the Robert H. and Clarice Smith and Abigail Van Buren Alzheimer's Disease Research Program.
The authors have no conflicts of interest to disclose. The sponsors had neither a role in the analysis or interpretation of these data, nor in the content of the manuscript. Appropriate approval procedures were used concerning human subjects.
ABSTRACT