title: Low bone mineral density is present in newly diagnosed paediatric systemic lupus erythematosus patients.
abstract: OBJECTIVE
  The objectives of this study were to (1) determine the prevalence of low bone mineral density (BMD) in a large prospective cohort of newly diagnosed patients with paediatric systemic lupus erythematosus (pSLE) and (2) identify risk factors associated with low BMD.
  
  
  METHODS
  Single-centre cohort study of 80 children and adolescents who underwent a dual-energy x-ray absorptiometry within 3 months of diagnosis. Low lumbar spine (LS) BMD was defined as z score ≤ -2.0. BMD was correlated with baseline demographic, clinical and laboratory markers of disease activity and biochemical markers of bone health. Risk factors of BMD were evaluated with univariable and multivariable linear and logistic regression analyses.
  
  
  RESULTS
  Low BMD at any site was found in 15% of newly diagnosed pSLE patients. LS BMD was associated with body mass index (BMI) z score and corrected calcium (r(2)=0.31, p<0.0001). Hip BMD was associated with BMI z score and intact parathyroid hormone (iPTH) (r(2)=0.26, p=0.002). Higher BMI z score was protective against low BMD at any site (OR 0.35).
  
  
  CONCLUSIONS
  One in six newly diagnosed pSLE patients had low BMD (at any site). Low BMI z score, low calcium and high iPTH identified children at risk for low BMD at diagnosis of pSLE.
authors.affiliation: Department of Pediatrics, Division of Rheumatology, The Hospital for Sick Children, University of Toronto, Toronto, Ontario, Canada.
authors.forename: Siok Hoon Lily
authors.initials: SH
authors.lastname: Lim
authors.forename: Susanne M
authors.initials: SM
authors.lastname: Benseler
authors.forename: Pascal N
authors.initials: PN
authors.lastname: Tyrrell
authors.forename: Martin
authors.initials: M
authors.lastname: Charron
authors.forename: Elizabeth
authors.initials: E
authors.lastname: Harvey
authors.forename: Diane
authors.initials: D
authors.lastname: Hebert
authors.forename: Earl D
authors.initials: ED
authors.lastname: Silverman
mesh_terms: D015502:Absorptiometry, Photon / Q000379:methods; D000293:Adolescent; D015519:Bone Density / Q000187:drug effects / Q000502:physiology; D002648:Child; D002675:Child, Preschool; D004812:Epidemiologic Methods; D005260:Female; D005938:Glucocorticoids / Q000494:pharmacology / Q000627:therapeutic use; D006621:Hip Joint / Q000503:physiopathology; D006801:Humans; D008159:Lumbar Vertebrae / Q000503:physiopathology; D008180:Lupus Erythematosus, Systemic / Q000150:complications* / Q000188:drug therapy / Q000503:physiopathology; D008297:Male; D010024:Osteoporosis / Q000209:etiology* / Q000503:physiopathology
chemical_list: D005938:Glucocorticoids