Marathon Running and Cell-Cycle Arrest Biomarkers of Acute Kidney Injury

Objectives: Endurance exercise is known to cause a rise in serum creatinine. It is not known to what extent this rise reflects renal stress and a potential acute kidney injury (AKI). Increases in Insulin Like Growth Factor Binding Protein 7 (IGFBP7) and Tissue Inhibitor of Metalloprotinases-2 (TIMP-2), urinary biomarkers of cell cycle arrest and renal stress, are associated with the development of AKI in clinical populations.Design: Repeated measures study.Methods: Runners were recruited at the 2019 Brighton Marathon (UK) and provided urine and blood samples at baseline, immediately post-race and 24 h post-race. Serum creatinine, urinary creatinine and urinary IGFBP7 and TIMP-2 were analysed from the samples.Results: Seventy nine participants (23 females, 56 males), aged 43 +/- 10 yrs. (mean +/- SD), finish time 243 +/- 40mins were included for analysis. Serum creatinine increased over the race by 40 +/- 26% (p < 0.001), TIMP-2 increased by 555 +/- 697% (p < 0.001) and IGFBP7 increased by 1094 +/- 1491% (p < 0.001) over the race. A subset of twenty-two participants supplied samples 24 h post-race, reporting values similar to baseline for all variables.Conclusions: This study is the first to report large rises in IGFBP7 and TIMP-2 following marathon running. This suggests that rises in creatinine are not fully explained by changes in production and clearance and marathon running induces a state of kidney stress and potential injury.(c) 2022 Sports Medicine Australia. Published by Elsevier Ltd. All rights reserved.