title: Effect of body composition on bone mineral density in Moroccan patients with juvenile idiopathic arthritis.
abstract: BACKGROUND
  The link between bone mass and body composition is widely recognized, but only few works were selectively performed on subjects with juvenile idiopathic arthritis. The aim of our study was to investigate the effect of body composition on bone mineral density (BMD) in Moroccan patients with juvenile idiopathic arthritis.
  
  
  METHODS
  Thirty three children with juvenile idiopathic arthritis (JIA) were included in a cross-sectional study. The diagnosis of JIA was made according to the criteria of the International League of Association of Rheumatology (ILAR). Body mass index (BMI) was calculated from the ratio of weight/height(2)(kg/m(2)). Pubertal status was determined according to the Tanner criteria. Bone status, body composition and bone mineral content (BMC) were analyzed by using dual-energy X-ray absorptiometry (DXA). BMD was assessed at the lumbar spine (L1-L4) and at total body in (g/cm(2)). Total body fat tissue mass (FTM) and lean tissue mass (LTM) were also analyzed by DXA and expressed in kilograms. In children, low BMD was defined as a Z-score less than -2 and osteoporosis was defined as a Z-score less than -2 with a fracture history.
  
  
  RESULTS
  A cross-sectional study was conducted in 33 Moroccan patients with JIA aged between 4 and 16 years, Fat mass was not related to bone density; in contrast, BMD was positively associated to LTM in total body(r = =0.41, p= 0.04) but not in lumbar spine (r = 0.29, p= 0.17). There exist significant correlation between BMC and BMD in total body (r = 0.51, p = 0.01).
  
  
  CONCLUSIONS
  This study suggests that the LTM is a determining factor of the BMD during adolescence. Other studies with a broader sample would be useful to confirm this relation.
authors.affiliation: Department of Rheumatology, EL Ayachi Hospital, University Hospital of Rabat-Sale, 11000, Sale, Morocco.
authors.forename: Dalal
authors.initials: D
authors.lastname: El Badri
authors.affiliation: Department of Rheumatology, EL Ayachi Hospital, University Hospital of Rabat-Sale, 11000, Sale, Morocco.
authors.forename: Samira
authors.initials: S
authors.lastname: Rostom
authors.affiliation: Department of Rheumatology, EL Ayachi Hospital, University Hospital of Rabat-Sale, 11000, Sale, Morocco.
authors.forename: Ilham
authors.initials: I
authors.lastname: Bouaddi
authors.affiliation: Department of Rheumatology, EL Ayachi Hospital, University Hospital of Rabat-Sale, 11000, Sale, Morocco.
authors.forename: Asmae
authors.initials: A
authors.lastname: Hassani
authors.affiliation: Department of Pediatrics, children's Hospital, University Hospital of Rabat-Sale, 11000, Rabat, Morocco.
authors.forename: Bouchra
authors.initials: B
authors.lastname: Chkirate
authors.affiliation: Department of Rheumatology, EL Ayachi Hospital, University Hospital of Rabat-Sale, 11000, Sale, Morocco.
authors.forename: Bouchra
authors.initials: B
authors.lastname: Amine
authors.affiliation: Department of Rheumatology, EL Ayachi Hospital, University Hospital of Rabat-Sale, 11000, Sale, Morocco.
authors.forename: Najia
authors.initials: N
authors.lastname: Hajjaj-Hassouni
mesh_terms: D000293:Adolescent; D001171:Arthritis, Juvenile / Q000000981:diagnostic imaging* / Q000378:metabolism*; D001823:Body Composition; D015519:Bone Density; D002648:Child; D002675:Child, Preschool; D003430:Cross-Sectional Studies; D005260:Female; D006801:Humans; D008297:Male; D009018:Morocco / Q000453:epidemiology; D011859:Radiography
keywords: Body composition; fat mass; juvenile idiopathic arthritis; lean mass