title: Analysis on the serum levels of the biomarker CTX-II in professional indoor soccer players over the course of one season.
abstract: OBJECTIVE
  The aim of this study was to analyze the blood serum levels of CTX-II in professional indoor soccer players, at three different times during one season: at the start of the pre-season, four months later (a time that marks the middle of the season) and at the end of the season.
  
  
  METHODS
  Fourteen male soccer players of mean age 19 years were included. Blood samples of 3 mL were collected from each individual. The samples were analyzed by means of Elisa tests.
  
  
  RESULTS
  There was a significant increase in the serum level of CTX-II in the indoor soccer players, from the beginning to the end of the season (p < 0.01).
  
  
  CONCLUSIONS
  These data suggest that joint degradation had occurred in these soccer players, by the end of this period. It is evident that further studies are needed, with methodological rigor, so as to make an effective contribution toward precise elucidation of the etiology of this osteoarthritis and its relationship with the biomarkers, as a tool for early diagnosis.
authors.affiliation: School of Medical Sciences, Santa Casa de São Paulo, São Paulo, SP, Brazil.
authors.forename: Rodrigo Miziara
authors.initials: RM
authors.lastname: Severino
authors.affiliation: School of Medical Sciences, Santa Casa de São Paulo, São Paulo, SP, Brazil.
authors.forename: Pedro Baches
authors.initials: PB
authors.lastname: Jorge
authors.affiliation: School of Medical Sciences, Santa Casa de São Paulo, São Paulo, SP, Brazil.
authors.forename: Mauro Olivo
authors.initials: MO
authors.lastname: Martinelli
authors.affiliation: School of Medical Sciences, Santa Casa de São Paulo, São Paulo, SP, Brazil.
authors.forename: Marcos Vaz
authors.initials: MV
authors.lastname: de Lima
authors.affiliation: School of Medical Sciences, Santa Casa de São Paulo, São Paulo, SP, Brazil.
authors.forename: Nilson Roberto
authors.initials: NR
authors.lastname: Severino
authors.affiliation: School of Medical Sciences, Santa Casa de São Paulo, São Paulo, SP, Brazil.
authors.forename: Aires
authors.initials: A
authors.lastname: Duarte Junior
keywords: Joint cartilage; Osteoarthritis; Pharmacological biomarkers