Urinary Kidney Injury Molecule-1 but Not Urinary Neutrophil Gelatinase Associated Lipocalin Is Increased after Short Maximal Exercise

Abstract

Background and Aims: Urinary neutrophil gelatinase associated lipocalin (uNGAL) and urinary kidney injury molecule-1 (uKIM-1) are markers of acute kidney injury. The albuminuria is a well-known abnormality after physical exercise. The aim of this study was to investigate changes in uNGAL and uKIM-1 after intensive exercise causing albuminuria. Methods: The study population consisted of 19 participants (10 males and 9 females). The mean age of participants was 35.74 years. All were fit amateur runners; the mean body mass index was 21.99 in females and 24.71 in males. The subjects underwent a graded treadmill exercise test (GXT) according to the Bruce protocol. Maximal oxygen consumption (VO₂max) was measured. Immediately before and after the test urine was collected. Urinary creatinine, albumin, NGAL, and KIM-1 were measured. Albumin to creatinine (ACR), KIM-1 to creatinine (KCR), and NGAL to creatinine (NCR) ratios were calculated. Results: The mean VO₂max was 53.68 in females and 59.54 mL/min/kg in males. Albuminuria and ACR were significantly higher after exercise. An increase in the ACR from 8.82 to 114.35 mg/g (p < 0.01) was observed. uKIM-1 increased significantly after exercise from 849.02 to 1,243.26 pg/mL (p < 0.05). KCR increased from 1,239.1 to 1,725.9 ng/g but without statistical significance (p = 0.07). There were no statistical changes in pre- and post-run uNGAL levels. There was no correlation between post-GXT albuminuria and uKIM-1. Conclusions: uKIM-1 is a very sensitive marker of kidney dysfunction. In our study, uKIM-1 increased significantly after a very short period of exercise. It is not clear if the increase in KIM-1 is caused by post-exercise albuminuria.

Incremental short maximal exercise increases urinary liver‐type fatty acid‐binding protein in adults without CKD

“…22 Moreover, the studies that examined acute effects of high-intensity exercise on kidney, including the present study, consistently report that the kidney is transiently and adversely affected by this type of exercise. 10,11 These findings suggest that acute effects of high-intensity exercise on kidney differ evidently from chronic effects of habitual exercise on the same; furthermore, this difference appears to depend heavily on the exercise intensity.…”

“…The follow‐up evaluations post‐exercise were needed to examine the transient changes in the urinary parameters obtained from the urine produced during the exercise. Secondly, we did not measure the other urinary tubular biomarkers, such as urinary KIM‐1 and NGAL which were also reported to transiently increase after the high‐intensity exercise . Further studies are needed to clarify which urinary tubular biomarkers are more sensitive indicators.…”

“…Secondly, we did not measure the other urinary tubular biomarkers, such as urinary KIM-1 and NGAL which were also reported to transiently increase after the high-intensity exercise. 10,11 Further studies are needed to clarify which urinary tubular biomarkers are more sensitive indicators. Thirdly, the evaluation on renal blood flow was not performed in this study; therefore, it is unknown whether the increase in urinary L-FABP levels was associated with the reduction in renal blood flow with the exercise.…”

“…9 Furthermore, several acute kidney injury biomarkers such as urinary neutrophil gelatinase associated-lipocalin (NGAL) and kidney injury molecule-1 (KIM-1) were also reported to transiently increase after the high-intensity exercise. 10,11 These findings indicate the possibility that high-intensity exercise induces not only glomerular abnormality but also tubular hypoxia/ ischemia, which is one of the aggravating factors of tubulointerstitial damage. Due to the fact that tubulointerstitial damage is related to progression of chronic kidney disease (CKD) rather than glomerular damage, 12 investigating the possibility of acute adverse effects on tubular conditions caused by the high-intensity exercise, may be of importance to prevent an onset of CKD or deterioration of renal function.…”

“…Post‐exercise proteinuria (ie, albuminuria) is a well‐known renal (glomerular) abnormality after high‐intensity exercise . Furthermore, several acute kidney injury biomarkers such as urinary neutrophil gelatinase associated‐lipocalin (NGAL) and kidney injury molecule‐1 (KIM‐1) were also reported to transiently increase after the high‐intensity exercise . These findings indicate the possibility that high‐intensity exercise induces not only glomerular abnormality but also tubular hypoxia/ischemia, which is one of the aggravating factors of tubulointerstitial damage.…”