Evaluation of pro-inflammatory cytokines in frail Tunisian older adults

PLoS One. 2020 Nov 9;15(11):e0242152. doi: 10.1371/journal.pone.0242152. eCollection 2020.

Abstract

The present study was undertaken to evaluate serum levels of pro-inflammatory cytokines in Tunisian older adults and to examine the relationships between inflammatory marker levels, geriatric, and biochemical parameters. A cross-sectional study was conducted in a population of Tunisian older adults (N = 141, aged 65 and over). Patients were recruited from the Department of Internal Medicine, Fattouma Bourguiba University Hospital (Monastir, Tunisia) and from a nursing home (Sousse, Tunisia). Comprehensive geriatric assessment, history taking and examination including functional and nutritional assessment were done for each participant. Enzyme-linked immunosorbent assay (ELISA) test was used to measure serum cytokine (TNF-α, IL-8, IL-6) levels. The modified Short Emergency Geriatric Assessment score (SEGAm) were used to classify patients as 51 very-frail, 40 frail, and 50 non-frail. The age of the participants (80 men, 61 women) ranged from 65 to 97 years. Serum levels of TNF-α, IL-8 and C-reactive protein (CRP) were significantly higher in very-frail participants compared to frail and non-frail ones. However, no significant differences in IL-6 levels were detected among frailty groups. After adjustment for age, CRP and IL-8 levels remained significantly associated with frailty. Analysis of the receiver operating characteristic (ROC) curve corresponding to IL-8 showed an area under the curve of 0.7 (p = 0.003; 95% CI [0.58-0.81]) and a predictive threshold of 5.27 pg/ml. Positive correlations were found between frailty score, IL-6, and IL-8 levels. In addition, a significant positive correlation was observed between IL-8 levels and Timed Up and Go test results. However, a negative correlation was observed between Mini Nutritional Assessment Short-Form score, IL-6 and CRP levels, as well as between Activities of Daily Living score and serum levels of TNF-α, IL-6, and CRP. In conclusion, the key findings of this study collectively support a role of pro-inflammatory cytokines, TNF-α, CRP, and especially IL-8 in the development of frailty in older adults.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Aged
  • Aged, 80 and over
  • Biomarkers / blood
  • C-Reactive Protein / analysis
  • Cross-Sectional Studies
  • Cytokines / blood*
  • Enzyme-Linked Immunosorbent Assay
  • Female
  • Frail Elderly*
  • Frailty / epidemiology
  • Geriatric Assessment / methods
  • Humans
  • Inflammation / metabolism*
  • Interleukin-6 / blood
  • Interleukin-8 / blood
  • Male
  • ROC Curve
  • Tumor Necrosis Factor-alpha / blood
  • Tunisia / epidemiology

Substances

  • Biomarkers
  • CXCL8 protein, human
  • Cytokines
  • IL6 protein, human
  • Interleukin-6
  • Interleukin-8
  • Tumor Necrosis Factor-alpha
  • C-Reactive Protein

Grants and funding

The source of Funding (financial and material support) for our study was received from our institution (CHU F Bourguiba). The funders had no role in study design, data collection and analysis, decision to publish, or preparation of the manuscript. No salary received from any of our funders. The authors received no specific funding for this work.