title: Glomerular filtration rate in endurance athletes.
abstract: OBJECTIVE
  The interpretation of biochemical testing in sportsmen requires caution. Although creatinine-based estimates of glomerular filtration rate (GFR) overcome some shortcomings of serum creatinine, there is scarce information on their use in endurance athletes.
  
  
  METHODS
  We evaluated GFR, estimated by the recommended Modification of Diet in Renal Disease (MDRD) equation in athletes.
  
  
  METHODS
  Seventy-six professional male cyclists, 71 amateur male cyclists, and 65 healthy sedentary matched controls were included in the study.
  
  
  RESULTS
  The mean serum creatinine level was significantly higher in the sedentary subjects (81 microM) than in amateur (75 microM; P < 0.001) and professional cyclists (72 microM; P < 0.001), and it was also marginally higher in amateur than in professional cyclists (P = 0.049). The mean estimated GFR value increased throughout the three subgroups, being significantly lower in the sedentary population (98 mL.min.[1.73 m]) than in the subgroups of amateur (109 mL.min.[1.73 m]; P < 0.001) and professional cyclists (113 mL.min.[1.73 m]; P < 0.001), but it did not differ between amateur and professional cyclists (P = 0.116). The average intensity of daily physical exercise, but not the body mass index, was inversely associated with serum creatinine and positively associated with the estimated GFR.
  
  
  CONCLUSIONS
  The MDRD equation should be used with caution in athletes, and it should consider intensity and type of physical exercise.
authors.affiliation: Sezione di Chimica Clinica, Dipartimento di Scienze Morfologico-Biomediche, Università di Verona, Verona, Italy. ulippi@tin.it
authors.forename: Giuseppe
authors.initials: G
authors.lastname: Lippi
authors.forename: Giuseppe
authors.initials: G
authors.lastname: Banfi
authors.forename: Gian Luca
authors.initials: GL
authors.lastname: Salvagno
authors.forename: Massimo
authors.initials: M
authors.lastname: Franchini
authors.forename: Gian Cesare
authors.initials: GC
authors.lastname: Guidi
mesh_terms: D001642:Bicycling / Q000502:physiology; D005919:Glomerular Filtration Rate / Q000502:physiology*; D006403:Hematologic Tests; D006801:Humans; D008297:Male; D010807:Physical Endurance; D013177:Sports / Q000502:physiology*