title: Firefighter Work Duration Influences the Extent of Acute Kidney Injury.
abstract: We tested the hypothesis that elevations in biomarkers of acute kidney injury are influenced by the magnitude of hyperthermia and dehydration elicited by two common firefighter work durations.
  
  
  
  Twenty-nine healthy adults (10 females) wearing firefighter protective clothing completed two randomized trials where they walked at 4.8 km·h, 5% grade in a 38°C, 50% RH environment. In the short trial, subjects completed two 20-min exercise bouts. In the long trial (LONG), subjects completed three 20-min exercise bouts. Each exercise bout was separated by 10 min of standing rest in an ~20°C environment. Venous blood samples were obtained before and immediately after exercise, and after 1 h recovery. Dependent variables included changes in core temperature, body weight, plasma volume, serum creatinine, and plasma neutrophil gelatinase-associated lipocalin, a marker of renal tubule injury.
  
  
  
  Changes in core temperature (+2.0°C ± 0.7°C vs +1.1°C ± 0.4°C, P < 0.01), body weight (-0.9% ± 0.6% vs -0.5% ± 0.5%, P < 0.01), and plasma volume (-11% ± 5% vs -8% ± 6%, P < 0.01) during exercise were greater in LONG. Increases in creatinine were higher in LONG postexercise (0.18 ± 0.15 vs 0.08 ± 0.07 mg·dL, P < 0.01) and after recovery (0.21 ± 0.16 vs 0.14 ± 0.10 mg·dL, P < 0.01). Increases in neutrophil gelatinase-associated lipocalin were greater in LONG postexercise (27.0 ± 20.5 vs 12.7 ± 18.0 ng·mL, P = 0.01) and after recovery (16.9 ± 15.6 vs 1.5 ± 15.1 ng·mL, P = 0.02).
  
  
  
  Biomarkers of acute kidney injury are influenced by the magnitude of hyperthermia and hypovolemia elicited by exercise in the heat.
authors.affiliation: 1Department of Exercise and Nutrition Sciences, Center for Research and Education in Special Environments, University at Buffalo, Buffalo, NY; and 2Department of Physiology and Biophysics, University at Buffalo, Buffalo, NY.
authors.forename: Zachary J
authors.initials: ZJ
authors.lastname: Schlader
authors.forename: Christopher L
authors.initials: CL
authors.lastname: Chapman
authors.forename: Suman
authors.initials: S
authors.lastname: Sarker
authors.forename: Lindsey
authors.initials: L
authors.lastname: Russo
authors.forename: Todd C
authors.initials: TC
authors.lastname: Rideout
authors.forename: Mark D
authors.initials: MD
authors.lastname: Parker
authors.forename: Blair D
authors.initials: BD
authors.lastname: Johnson
authors.forename: David
authors.initials: D
authors.lastname: Hostler
mesh_terms: D058186:Acute Kidney Injury / Q000175:diagnosis* / Q000209:etiology; D000328:Adult; D015415:Biomarkers / Q000097:blood; D001831:Body Temperature; D001835:Body Weight; D003404:Creatinine / Q000097:blood; D003681:Dehydration / Q000150:complications*; D005260:Female; D061388:Firefighters; D018882:Heat Stress Disorders / Q000150:complications*; D006358:Hot Temperature / Q000009:adverse effects; D006801:Humans; D000071068:Lipocalin-2 / Q000097:blood; D008297:Male; D010953:Plasma Volume; D011481:Protective Clothing / Q000009:adverse effects
chemical_list: D015415:Biomarkers; D000071068:Lipocalin-2; D003404:Creatinine