Association between C-reactive protein and cognitive deficits in elderly men and women: a meta-analysis

Background: Certain risk factors for cognitive decline appear modifiable. A potentially modifiable marker of inflammation, C-reactive protein may be associated with cognitive deficits, although not all studies have found a relationship between C-reactive protein and cognitive ability. Further, few research papers have examined whether gender may affect any association between C-reactive protein and cognitive deficit. Methods: To better understand the association between C-reactive protein, cognitive deficit, and gender in elderly people, we meta-analyzed cross-sectional studies that reported cognitive ability assessed by the Mini-Mental State Examination or an equivalent measure, C-reactive protein concentrations, and gender. Results: While we identified no studies containing only male subjects, the two identified studies containing both female and male subjects (n = 2,525) showed an effect size for cognition of -0.1809 (95% confidence interval, -0.2652 to -0.0967, p = 0.000025) between high and low C-reactive-protein groups. In contrast, the two identified studies containing only female subjects (n = 1,754) showed an effect size for cognition of 0.0345 (95% confidence interval, -0.0594 to 0.1285, not significant). Conclusions: In the context of a small number of source studies and lack of an all-male group, these results suggest that any association between C-reactive protein and cognitive deficits may be stronger in elderly men than in elderly women.