HEALTH NEWS

Study Title:

C-Reactive Protein and Cognitive Function

Study Abstract

Objective: C-reactive protein is a marker of inflammation and vascular disease. It also seems to be associated with an increased risk of dementia. To better understand potential underlying mechanisms, we assessed microstructural brain integrity and cognitive performance relative to serum levels of high-sensitivity C-reactive protein (hs-CRP).

Methods: We cross-sectionally examined 447 community-dwelling and stroke-free individuals from the Systematic Evaluation and Alteration of Risk Factors for Cognitive Health (SEARCH) Health Study (mean age 63 years, 248 female). High-field MRI was performed in 321 of these subjects. Imaging measures included fluid-attenuated inversion recovery sequences for assessment of white matter hyperintensities, automated quantification of brain parenchyma volumes, and diffusion tensor imaging for calculation of global and regional white matter integrity, quantified by fractional anisotropy (FA). Psychometric analyses covered verbal memory, word fluency, and executive functions.

Results: Higher levels of hs-CRP were associated with worse performance in executive function after adjustment for age, gender, education, and cardiovascular risk factors in multiple regression analysis (β = –0.095, p = 0.02). Moreover, higher hs-CRP was related to reduced global fractional anisotropy (β = –0.237, p < 0.001), as well as regional FA scores of the frontal lobes (β = –0.246, p < 0.001), the corona radiata (β = –0.222, p < 0.001), and the corpus callosum (β = –0.141, p = 0.016), in particular the genu (β = –0.174, p = 0.004). We did not observe a significant association of hs-CRP with measures of white matter hyperintensities or brain atrophy.

Conclusion: These data suggest that low-grade inflammation as assessed by high-sensitivity C-reactive protein is associated with cerebral microstructural disintegration that predominantly affects frontal pathways and corresponding executive function.

From press release:

New research shows that a high level of C-reactive protein (CRP), a marker for inflammation in the blood, is associated with brain changes that are linked to problems with executive thinking skills. The study is published in the March 30, 2010, issue of Neurology®, the medical journal of the American Academy of Neurology.

For the study, scientists examined 447 stroke and dementia-free people with an average age of 63.

Participants underwent MRI brain scans such as diffusion tensor imaging (DTI), a technique that measures water molecule movements in the brain. They also completed tests that measured verbal memory, word fluency and executive function, the process in the brain that allows for planning, decision making and selection of appropriate behavior.

The study found that higher levels of CRP led to worse performance in executive function. Higher levels of the protein also affected the frontal lobe of the brain, where some motor functions take place. Motor skills, however, were not measured in the study. Other areas of cognition, such as memory and language skills, showed no association with CRP.

Overall, the average time to complete a test of executive function was 85 seconds. Those with the highest levels of CRP took an average of seven seconds longer to complete the test than those with the lowest levels of the protein. The brain changes measured with DTI were equivalent to 12 years of aging for those with the highest levels of CRP compared to those with the lowest levels.

Study Information

H. Wersching, MD, T. Duning, MD, H. Lohmann, PhD, S. Mohammadi, PhD, C. Stehling, MD, M. Fobker, MD, M. Conty, J. Minnerup, MD, E.B. Ringelstein, MD, K. Berger, MD, M. Deppe, PhD and S. Knecht, MD.
Serum C-reactive protein is linked to cerebral microstructural integrity and cognitive function
Neurology
2010 March
Department of Neurology, Institute of Epidemiology and Social Medicine, Institute of Clinical Radiology, and Institute of Clinical Chemistry and Laboratory Medicine, University of Münster, Münster, Germany.