Prevalence and etiology of low bone mineral density in juvenile systemic lupus erythematosus.
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.
Compeyrot-Lacassagne
Sandrine
S
Hospital for Sick Children, University of Toronto, Toronto, Ontario, Canada.
Tyrrell
Pascal N
PN
Atenafu
Eshetu
E
Doria
Andrea S
AS
Stephens
Derek
D
Gilday
David
D
Silverman
Earl D
ED
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
D000305:Adrenal Cortex Hormones