Early biomarkers for kidney injury in heat-related illness patients: a prospective observational study at Japanese Self-Defense Force Fuji Hospital

• Published in: Nephrology, dialysis, transplantation Vol. 38; no. 3; pp. 644 - 654
• Main Authors: Goto, Hiroyasu, Shoda, Shinichi, Nakashima, Hiroyuki, Noguchi, Midori, Imakiire, Toshihiko, Ohshima, Naoki, Kinoshita, Manabu, Tomimatsu, Soichi, Kumagai, Hiroo
• Format: Journal Article
• Language: English
• Published: England Oxford University Press 28.02.2023
• Subjects: Acute Kidney Injury - diagnosis; Biomarkers; East Asian People; Fatty Acid-Binding Proteins - urine; Heat Stroke; Hot Temperature; Humans; Kidney; Lipocalin-2; Lipocalins; Original; KIM-1; heatstroke; cystatin C; L-FABP; acute kidney injury; heat-related illness
• ISSN: 0931-0509; 1460-2385
• DOI: 10.1093/ndt/gfac166

Abstract Background Since heatstroke-induced acute kidney injury (AKI) can progress to chronic kidney disease, it would be useful to detect heatstroke-induced AKI and severe heat-related illness in the early phase. We studied the epidemiology of heat-related illness among patients in the Japanese Ground Self-Defense Force and evaluated the relationship between heat-related illness severity and early urinary biomarkers for AKI. Methods We enrolled patients who were diagnosed with heat-related illness at the Self-Defense Force Fuji Hospital from 1 May to 30 September 2020. We compared the urinary kidney injury molecule-1 (KIM-1), neutrophil gelatinase-associated lipocalin (NGAL), liver fatty acid–binding protein (L-FABP), N-acetyl-β-D-glucosaminidase (NAG) and β2-microglobulin levels according to the severity of heat-related illness as defined by positive scores for the Japanese Association of Acute Medicine Heatstroke Working Group (JAAM-HS-WG) criteria (0, mild; 1, moderate; ≥2, severe). Results Of the 44 patients, kidney injury, defined as serum creatinine (sCr) ≥1.2 mg/dL, was seen in 9 (20.5%) patients. Urinary NAG, NGAL and L-FABP levels were significantly higher in the ≥2 JAAM-HS-WG criteria group than in the 0 group. Furthermore, urinary L-FABP levels were positively correlated with sCr levels. In contrast, the urinary KIM-1 levels showed the best correlation with serum cystatin C (sCysC) among these biomarkers. Conclusions We conclude even mild to moderate heatstroke could lead to AKI. Urinary L-FABP is useful for detecting heatstroke-induced AKI and patients with severe heat-related illness requiring immediate treatment. Urinary KIM-1 may detect heatstroke-induced AKI in terms of sCysC, although it was not related to the severity of heat-related illness. Graphical Abstract Graphical Abstract