Association between serum osteoprotegerin level and mortality in kidney transplant recipients - a prospective observational cohort study

Transpl Int. 2021 May;34(5):844-854. doi: 10.1111/tri.13847. Epub 2021 Mar 18.

Abstract

Paradoxically, higher serum levels of osteoprotegerin (OPG: a vascular calcification inhibitor) have been associated with increased arterial stiffness, risk of cardiovascular disease and all-cause mortality. A few studies reported that post-transplant OPG levels are associated with mortality in kidney transplant (KT) recipients. In this study, this association was assessed in a cohort of prevalent KT recipients, adjusting for previously untested potential confounders, including fibroblast growth factor 23 (FGF23) and interleukin 6 (IL-6). Socio-demographic and clinical parameters, medical and transplant history, and laboratory data were collected from 982 prevalent KT recipients. The association between serum OPG and all-cause mortality over a 6-year follow-up period was examined using Kaplan-Meier survival curves and multivariable-adjusted Cox regression models. Participants with high serum OPG were more likely female, older, deceased donor KT recipients and have more comorbidity, lower eGFR, higher FGF23, higher IL-6, and longer dialysis vintage. Each 1 pmol/l higher serum OPG level was associated with a 49% higher risk of mortality (hazard ratio (HR) [95% confidence interval (CI)]: 1.49 [1.40-1.61]). This association persisted after adjusting for confounders (HR [95% CI]: 1.20 [1.10-1.30]). In conclusion, serum OPG was associated with all-cause mortality independent of several novel confounders in prevalent KT recipients.

Keywords: cardiovascular disease; chronic kidney disease-mineral and bone disorder; kidney transplant; osteoprotegerin; outcomes; vascular calcification.

Publication types

  • Observational Study
  • Research Support, Non-U.S. Gov't

MeSH terms

  • Biomarkers / blood
  • Female
  • Fibroblast Growth Factor-23
  • Humans
  • Kidney Transplantation* / mortality
  • Male
  • Osteoprotegerin* / blood
  • Prospective Studies
  • Risk Factors
  • Transplant Recipients

Substances

  • Biomarkers
  • FGF23 protein, human
  • Osteoprotegerin
  • Fibroblast Growth Factor-23