CRP and hyperhomocysteinemia: A synergistic effect of both factors could be hypothesized, leading to faster cognitive decline and dementia (21).They found that high serum C-reactive protein (CRP) levels, especially in association with concurrent high serum Interleukin-6 (IL- 6) levels was a significant predictor of the risk of vascular dementia independently of hyperhomocysteinemia(21).