title: Prevalence and etiology of low bone mineral density in juvenile systemic lupus erythematosus.
abstract: OBJECTIVE
  Studies of adults with systemic lupus erythematosus (SLE) have frequently demonstrated the presence of decreased bone mineral density (BMD). However, there have been few investigations in pediatric patients to date. This study was undertaken to determine the prevalence of low BMD in patients with juvenile SLE and to identify associated risk factors.
  
  
  METHODS
  We studied 64 consecutive patients with juvenile SLE in whom routine dual x-ray absorptiometry (DXA) scanning was performed. Lumbar spine osteopenia was defined as a BMD Z score of < -1 and > or = -2.5, and osteoporosis as a BMD Z score of < -2.5. Decreased hip BMD was defined as a value of < 80%. Data on disease activity, quality of life, disease-related damage, sex, ethnicity, body mass index, age at diagnosis, age at DXA, medication use and duration, clinical features, and puberty status were collected at the time of DXA.
  
  
  RESULTS
  Lumbar spine osteopenia was seen in 24 patients (37.5%) and osteoporosis in 13 (20.3%). Decreased hip BMD was present in 12 patients (18.8%). By univariate analysis, osteopenia was significantly correlated with age, disease duration, duration of corticosteroid use, cumulative corticosteroid dose, azathioprine use, cyclophosphamide use, lupus nephritis, and damage. Two additional variables, mycophenolate mofetil use and class III-IV nephritis, were associated with osteoporosis. Abnormal hip BMD was associated with disease duration, duration of corticosteroid use, and cumulative corticosteroid dose. By multivariate analysis, only disease duration remained in the model for osteoporosis and abnormal hip BMD, while cumulative corticosteroid dose was the variable associated with osteopenia.
  
  
  CONCLUSIONS
  These results indicate that osteopenia and osteoporosis are common in juvenile SLE and are associated more closely with increased disease duration than with cumulative corticosteroid dose.
authors.affiliation: Hospital for Sick Children, University of Toronto, Toronto, Ontario, Canada.
authors.forename: Sandrine
authors.initials: S
authors.lastname: Compeyrot-Lacassagne
authors.forename: Pascal N
authors.initials: PN
authors.lastname: Tyrrell
authors.forename: Eshetu
authors.initials: E
authors.lastname: Atenafu
authors.forename: Andrea S
authors.initials: AS
authors.lastname: Doria
authors.forename: Derek
authors.initials: D
authors.lastname: Stephens
authors.forename: David
authors.initials: D
authors.lastname: Gilday
authors.forename: Earl D
authors.initials: ED
authors.lastname: Silverman
mesh_terms: D015502:Absorptiometry, Photon; D000293:Adolescent; D000305:Adrenal Cortex Hormones / Q000009:adverse effects / Q000627:therapeutic use; D015519:Bone Density / Q000502:physiology*; D001851:Bone Diseases, Metabolic / Q000150:complications / Q000453:epidemiology / Q000503:physiopathology; D002648:Child; D015331:Cohort Studies; D018450:Disease Progression; D004305:Dose-Response Relationship, Drug; D005260:Female; D006801:Humans; D008180:Lupus Erythematosus, Systemic / Q000150:complications* / Q000188:drug therapy / Q000503:physiopathology; D008297:Male; D015999:Multivariate Analysis; D010024:Osteoporosis / Q000150:complications / Q000453:epidemiology* / Q000503:physiopathology; D015995:Prevalence; D012307:Risk Factors
chemical_list: D000305:Adrenal Cortex Hormones