This study is the first to examine the effect of marathon running on TIMP-2 and IGFBP, two urinary biomarkers of cell cycle arrest that strongly predict development of AKI in clinical populations. TIMP-2 and IGFBP7 increased following marathon running and this rise was moderately correlated with the rise in serum creatinine. Adjusting the TIMP-2 and IGFBP7 values for urinary creatine, reduced the magnitude of the increase but maintained the association with serum creatinine rise.

Measuring changes in serum creatinine concentration in the context of exercise, as in acute care settings, is an imperfect measure of acute kidney function, given the multiple other factors that may elevate serum creatinine. Exercise associated factors include impaired clearance due to reduced kidney blood flow secondary to intravascular volume depletion and increased release as a consequence muscle breakdown, processes that are augmented by exertional heat stroke and exercise induced renal artery vasoconstriction.

We were saddened to hear that the organisers have been struggling financially, but encouraged to hear that the council is supporting the Marathon to continue next year.