title: Effects of long-term administration of omeprazole on bone mineral density and the mechanical properties of the bone.
abstract: OBJECTIVE
  Epidemiological studies have shown a relationship between long-term use of proton pump inhibitors and bone metabolism. However, this relationship has not yet become established. The aim of the present study was to analyze the mechanical properties and bone mineral density (BMD) of rats that were subjected to long-term omeprazole use.
  
  
  METHODS
  Fifty Wistar rats weighing between 200 and 240 g were divided equally into five groups: OMP300 (omeprazole intake at a dose of 300 μmoL/kg/day); OMP200 (200 μmoL/kg/day); OMP40 (40 μmoL/kg/day); OMP10 (10 μmoL/kg/day); and Cont (control group; intake of dilution vehicle). The solutions were administered for 90 consecutive days. After the rats had been sacrificed, their BMD, the mechanical properties of the dissected femurs and their serum Ca++ levels were analyzed.
  
  
  RESULTS
  The BMD of the OMP300 group was lower than that of the controls (p = 0.006). There was no difference on comparing the OMP200, OMP40 and OMP10 groups with the controls. The maximum strength and rigidity of the femur did not differ in the experimental groups in comparison with the controls. The OMP300 group had a statistically lower serum Ca++ concentration than that of the controls (p = 0.049), but the other groups did not show any difference in relation to the controls.
  
  
  CONCLUSIONS
  Daily intake of 300 μmoL/kg/day of omeprazole decreased the BMD of the femur, but without changes to the rigidity and strength of the femur in adult rats.
authors.affiliation: Pouso Alegre School of Medical Sciences, Universidade do Vale do Sapucaí, Pouso Alegre, MG, Brazil.
authors.forename: Gabriela Rezende
authors.initials: GR
authors.lastname: Yanagihara
authors.affiliation: Pouso Alegre School of Medical Sciences, Universidade do Vale do Sapucaí, Pouso Alegre, MG, Brazil.
authors.forename: Aline Goulart
authors.initials: AG
authors.lastname: de Paiva
authors.affiliation: Pouso Alegre School of Medical Sciences, Universidade do Vale do Sapucaí, Pouso Alegre, MG, Brazil ; Department of Clinical Pathology, School of Medicine, Universidade de São Paulo, São Paulo, SP, Brazil.
authors.forename: Maurílio Pacheco
authors.initials: MP
authors.lastname: Neto
authors.affiliation: Department of Clinical and Toxicological Analyses, School of Pharmaceutical Sciences, Universidade de São Paulo, São Paulo, SP, Brazil.
authors.forename: Larissa Helena
authors.initials: LH
authors.lastname: Torres
authors.affiliation: Ribeirão Preto School of Medicine, Universidade de São Paulo, Ribeirão Preto, São Paulo, SP, Brazil.
authors.forename: Antônio Carlos
authors.initials: AC
authors.lastname: Shimano
authors.affiliation: Araçatuba School of Veterinary Medicine, Universidade Estadual Paulista Júlio Mesquita Filho, Araçatuba, São Paulo, SP, Brazil.
authors.forename: Mário Jefferson Quirino
authors.initials: MJ
authors.lastname: Louzada
authors.affiliation: Pouso Alegre School of Medical Sciences, Universidade do Vale do Sapucaí, Pouso Alegre, MG, Brazil.
authors.forename: Raquel
authors.initials: R
authors.lastname: Annoni
authors.affiliation: Pouso Alegre School of Medical Sciences, Universidade do Vale do Sapucaí, Pouso Alegre, MG, Brazil.
authors.forename: Álvaro César
authors.initials: ÁC
authors.lastname: de Oliveira Penoni
keywords: Bone; Bone density; Omeprazole; Rats