Original Research ARTICLE
Longitudinal associations between serum cytokine levels and dementia
- 1Chonnam National University Medical School, South Korea
- 2King's College London, United Kingdom
Background: The purpose of this study was to investigate whether long-term inflammation is related to the incidence of dementia in a prospective observational study.
Methods: In total, 732 Korean community-dwelling elderly people > 65 years were evaluated at baseline. Of the 625 without dementia, 518 (83%) were followed over a 2.4-year period, and the incidence of dementia was determined. Cytokine [interleukin (IL)-1α, IL-1β, IL-6, IL-8, and tumor necrosis factor (TNF)-α] levels were measured at baseline and follow-up. The individual and combined effects of cytokine levels on dementia were evaluated after adjusting for potential covariates (lifestyle factors, demographics, disability, cognitive function, and presence of the APOE e4 allele) and a Bonferroni correction.
Results: Incident dementia was associated with increased serum cytokine levels after 2 years; the association remained significant for TNF-α, IL1-α, and IL-1β concentrations even after applying a Bonferroni correction. The analysis of the combined effects of the five cytokines showed independent associations between increases in the summed number of higher cytokine levels, between baseline and follow-up. However, incident dementia was not expected based on higher baseline pro-inflammatory cytokine levels.
Conclusion: Our results suggest that dementia may precede changes in serum cytokine levels and inflammatory processes, rather than resulting from elevated pro-inflammatory cytokines.
Keywords: Dementia, Geriatric Psychiatry, Inflammation, Cytokines, Longitudinal Studies
Received: 30 Jul 2018;
Accepted: 30 Oct 2018.
Edited by:Wael M. Mohamed, International Islamic University Malaysia, Malaysia
Reviewed by:Antonio L. Teixeira, University of Texas Health Science Center at Houston, United States
Monika Zilkova, Institute of Neuroimmunology (SAS), Slovakia
Copyright: © 2018 Kim, Kim, Stewart, Kang, Bae, Kim, Shin and Yoon. This is an open-access article distributed under the terms of the Creative Commons Attribution License (CC BY). The use, distribution or reproduction in other forums is permitted, provided the original author(s) and the copyright owner(s) are credited and that the original publication in this journal is cited, in accordance with accepted academic practice. No use, distribution or reproduction is permitted which does not comply with these terms.
* Correspondence: Prof. Jae-Min Kim, Chonnam National University Medical School, Gwangju, South Korea, firstname.lastname@example.org