title: Incidence and Prevalence of Acute Kidney Injury During Multistage Ultramarathons.
abstract: OBJECTIVE
  Determine prevalence, incidence, and risk factors of acute kidney injury (AKI) during multistage ultramarathons.
  
  
  METHODS
  Prospective observational cohort study.
  
  
  METHODS
  Jordanian Desert 2012; Atacama Desert, Chile 2012 and 2013; and Gobi Desert 2013 RacingThePlanet 250 km, 6-stage, ultramarathons.
  
  
  METHODS
  One hundred twenty-eight participants (384 measurements) from the Jordan (25, 19.5%), Gobi (35, 27.3%), 2012 Atacama (24, 18.8%), and 2013 Atacama (44, 34.4%) races.
  
  
  METHODS
  Blood samples and weights were gathered and analyzed immediately after stage 1 (40 km), 3 (120 km), and 5 (225 km).
  
  
  METHODS
  Changes in serum creatinine (Cr), cumulative incidence, and prevalence of AKI were calculated for each stage with "risk of injury" defined as 1.5 × baseline Cr and "injury" defined as 2 × Cr.
  
  
  RESULTS
  Cumulative incidence of AKI was 41.4%. Stage 1 had 56 (43.8%) with risk of AKI and 24 (18.8%) with injury; in stage 3, 61 (47.7%) were at risk, 41 (32%) had injury; in stage 5, 62 (48.4%) runners were at risk and 36 (28.1%) had injury. Acute kidney injury was significantly associated with females [odds ratio (OR), 4.64; 95% confidence interval (CI), 2.07-10.37; P < 0.001], lower pack weight (OR, 0.71; 95% CI, 0.56-0.91; P < 0.007), and percentage weight loss (OR, 0.87; 95% CI, 0.78-0.97; P < 0.015). Lowest quintile of finishers was less likely to develop AKI (OR, 0.18; 95% CI, 0.04-0.78; P < 0.022).
  
  
  CONCLUSIONS
  Prevalence of AKI was 63%-78% during multistage ultramarathons. Female sex, lower pack weight, and greater weight loss were associated with renal impairment.
authors.affiliation: *Department of Emergency Medicine, Stanford University School of Medicine, Stanford, California; †Department of Rehabilitation, Orthopedics, and Sports Medicine, University of Washington, Seattle, Washington; and ‡Stanford-Kaiser Emergency Medicine Residency, Stanford University School of Medicine, Stanford, California.
authors.forename: Grant S
authors.initials: GS
authors.lastname: Lipman
authors.forename: Brian J
authors.initials: BJ
authors.lastname: Krabak
authors.forename: Sean D
authors.initials: SD
authors.lastname: Rundell
authors.forename: Katherine M
authors.initials: KM
authors.lastname: Shea
authors.forename: Natalie
authors.initials: N
authors.lastname: Badowski
authors.forename: Colin
authors.initials: C
authors.lastname: Little
mesh_terms: D058186:Acute Kidney Injury / Q000097:blood / Q000453:epidemiology*; D000328:Adult; D003404:Creatinine / Q000097:blood; D005260:Female; D005919:Glomerular Filtration Rate; D006801:Humans; D015994:Incidence; D008297:Male; D008875:Middle Aged; D015995:Prevalence; D011446:Prospective Studies; D012307:Risk Factors; D012420:Running; D012737:Sex Factors; D015431:Weight Loss
chemical_list: D003404:Creatinine