Abstract
Objectives: To assess whether C-reactive protein (CRP) and interleukin-6 (IL-6) are associated with low cognitive performance and decline in middle-aged adults. Design/setting: The Whitehall II study; an ongoing large-scale, prospective occupational cohort study of employees from 20 London-based white-collar Civil Service departments. Participants: Data from more than 3000 males and 1200 female employees. Measures: Inflammatory makers measured in 1991-1993 and five cognitive tests (short-term verbal memory, inductive reasoning (AH4-I), vocabulary (Mill Hill), and phonemic and semantic fluency) performed in 1997-1999 and 2002-2004. Performance in the lowest sex-specific quintile indicated low cognitive performance or decline. Covariates included sociodemographics, health behaviours and health conditions. Results: In age-adjusted analyses both CRP and IL-6 were associated with all cognitive measures in 1997-1999, even though the association with memory was not consistent. After extensive adjustment raised CRP levels were only associated with poor cognitive performance on the AH4-I (OR = 1.38; 95% CI: 1.05-1.82) and Mill Hill (OR = 1.52; 95% CI: 1.14-2.03) and IL-6 on semantic fluency (OR = 1.27; 95% CI: 1.14-2.03). Associations were more evident in men than in women. No clear relationship was observed for decline. Conclusions: Our results suggest that raised levels of inflammatory markers in midlife are moderately associated with lower cognitive status, but little with cognitive decline.
Original language | English (US) |
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Pages (from-to) | 1322-1334 |
Number of pages | 13 |
Journal | Psychoneuroendocrinology |
Volume | 33 |
Issue number | 10 |
DOIs | |
State | Published - Nov 2008 |
Externally published | Yes |
Keywords
- C-reactive protein
- Cognitive aging
- Inflammation
- Interleukin-6
- Midlife
- Prospective study
ASJC Scopus subject areas
- Endocrinology, Diabetes and Metabolism
- Endocrinology
- Endocrine and Autonomic Systems
- Psychiatry and Mental health
- Biological Psychiatry