Inflammation and elevated levels of fibroblast growth factor 23 are independent risk factors for death in chronic kidney disease

Kidney Int. 2017 Mar;91(3):711-719. doi: 10.1016/j.kint.2016.10.021. Epub 2016 Dec 22.

Abstract

Inflammation is a consequence of chronic kidney disease (CKD) and is associated with adverse outcomes in many clinical settings. Inflammation stimulates production of fibroblast growth factor 23 (FGF23), high levels of which are independently associated with mortality in CKD. Few large-scale prospective studies have examined inflammation and mortality in patients with CKD, and none tested the interrelationships among inflammation, FGF23, and risk of death. Therefore, we conducted a prospective investigation of 3875 participants in the Chronic Renal Insufficiency Cohort (CRIC) study with CKD stages 2 to 4 to test the associations of baseline plasma interleukin-6, high-sensitivity C-reactive protein, and FGF23 levels with all-cause mortality, censoring at the onset of end-stage renal disease. During a median follow-up of 6.9 years, 550 participants died (20.5/1000 person-years) prior to end-stage renal disease. In separate multivariable-adjusted analyses, higher levels of interleukin-6 (hazard ratio per one standard deviation increase of natural log-transformed levels) 1.35 (95% confidence interval, 1.25-1.46), C-reactive protein 1.28 (1.16-1.40), and FGF23 1.45 (1.32-1.60) were each independently associated with increased risk of death. With further adjustment for FGF23, the risks of death associated with interleukin-6 and C-reactive protein were minimally attenuated. Compared to participants in the lowest quartiles of inflammation and FGF23, the multivariable-adjusted hazard ratio of death among those in the highest quartiles of both biomarkers was 4.38 (2.65-7.23) for interleukin-6 and FGF23, and 5.54 (3.04-10.09) for C-reactive protein and FGF23. Thus, elevated levels of interleukin-6, C-reactive protein, and FGF23 are independent risk factors for mortality in CKD.

Keywords: CKD; FGF23; inflammation; mortality.

Publication types

  • Comparative Study
  • Multicenter Study
  • Observational Study

MeSH terms

  • Adult
  • Aged
  • Biomarkers / blood*
  • C-Reactive Protein / analysis
  • Female
  • Fibroblast Growth Factors / blood*
  • Humans
  • Inflammation / blood*
  • Inflammation / diagnosis
  • Inflammation / mortality*
  • Inflammation Mediators / blood
  • Interleukin-6 / blood
  • Kaplan-Meier Estimate
  • Kidney Failure, Chronic / blood
  • Kidney Failure, Chronic / diagnosis
  • Kidney Failure, Chronic / mortality
  • Male
  • Middle Aged
  • Multivariate Analysis
  • Prognosis
  • Proportional Hazards Models
  • Prospective Studies
  • Renal Insufficiency, Chronic / blood*
  • Renal Insufficiency, Chronic / diagnosis
  • Renal Insufficiency, Chronic / mortality*
  • Risk Assessment
  • Risk Factors
  • Time Factors
  • United States
  • Up-Regulation
  • Young Adult

Substances

  • Biomarkers
  • IL6 protein, human
  • Inflammation Mediators
  • Interleukin-6
  • Fibroblast Growth Factors
  • fibroblast growth factor 23
  • C-Reactive Protein