Changes in Circulating and Urinary Apoptosis Inhibitor of Macrophage Levels After Marathon Running

Abstract

Background: Completing a full marathon induces substantial physiological stress in the body, leading to an increase in biomarkers associated with transient acute kidney injury (AKI). In this study, we focused on the apoptosis inhibitor of macrophages (AIM) and kidney injury molecule-1 (KIM-1), non-intrusive biomarkers implicated in AKI, responsible for eliminating necrotic cellular entities in the renal milieu. Objectives: This study aimed to investigate the dynamics of AIM and KIM-1 levels in blood and urine samples before and after full marathons. Methods: Twenty-three male participants actively participated in a full marathon, and blood and urine samples were collected before and after the marathon. The measurements included plasma AIM, urinary AIM, and urinary KIM-1 levels. Results: Our results showed that plasma AIM levels significantly decreased (5.3 ± 2.1 vs. 4.5 ± 1.7 pg/mL), whereas urinary AIM and KIM-1 levels significantly increased after full marathons (0.21 ± 0.25 vs. 0.99 ± 1.10 pg/mL/g creatinine, 99.0 ± 40.9 vs. 136.9 ± 74.1 pg/mL/g creatinine). Furthermore, a positive correlation was observed between urinary AIM and KIM-1 levels concerning the amount of change after a full marathon (R = 0.560, P = 0.005). Conclusions: This study presents temporal variations in circulating and urinary AIM levels and urinary KIM-1 levels during a full marathon for the first time, suggesting their potential role as non-invasive urinary biomarkers for renal assessments.