Bone mass development and bone metabolism in juvenile idiopathic arthritis: treatment with growth hormone for 4 years.
OBJECTIVE
To study the acquisition of bone mass and changes in bone mineral density (BMD) related to age, bone age, pubertal status, and growth hormone (GH) therapy in 11 children with juvenile idiopathic arthritis (JIA) longitudinally over 4 years, in comparison to healthy children.


METHODS
Bone mineral content (BMC), BMD, and vertebral area were measured by dual energy x-ray absorptiometry. Since BMC and BMD increase with size, BMD was converted to volumetric BMD (vBMD) after adjustment for vertebral size.


RESULTS
At inclusion all patients (7 female, 4 male, mean age 10.3 +/- 2.1 yrs) had low BMD, with a mean z-score for area BMD (aBMD) of -2.04 +/- 0.8 SD. After adjustment for size, vBMD was 0.198 g/cm3, and after 4 years of GH treatment it increased significantly to 0.232 g/cm3 (p < 0.03), expressed as SD scores that increased from -2.97 +/- 0.81 SD to -2.83 +/- 0.67 SD. In relation to bone age, vBMD SD increased from -2.53 +/- 0.85 to -2.41 +/- 0.79. Compared to pretreatment values, bone formation and resorption markers increased significantly during treatment.


CONCLUSIONS
Our results reflect an increase in bone turnover under GH therapy in these patients. Despite biochemical changes there was a stabilization of vBMD for age and bone age, with a percentage increase comparable to healthy children. Longterm GH treatment will be necessary to evaluate a potential positive effect of GH on bone density and metabolism in patients with JIA.
Bechtold
Susanne
S
Endocrine Division, University Children's Hospital, Dr. von Haunersches Kinderspital, Lindwurmstrasse 4, 80337 Munich, Germany. Susanne.Bechtold@med.uni-muenchen.de
Ripperger
Peter
P
Bonfig
Walter
W
Schmidt
Heinrich
H
Bitterling
Harro
H
Häfner
Renate
R
Schwarz
Hans Peter
HP
D000293:Adolescent; D001171:Arthritis, Juvenile / Q000150:complications / Q000188:drug therapy / Q000503:physiopathology*; D001827:Body Height / Q000187:drug effects; D015519:Bone Density / Q000187:drug effects; D001846:Bone Development / Q000187:drug effects*; D016723:Bone Remodeling / Q000187:drug effects; D001842:Bone and Bones / Q000187:drug effects / Q000378:metabolism*; D002648:Child; D005183:Failure to Thrive / Q000209:etiology; D005260:Female; D005938:Glucocorticoids / Q000009:adverse effects; D006728:Hormones / Q000009:adverse effects / Q000627:therapeutic use; D019382:Human Growth Hormone / Q000627:therapeutic use*; D006801:Humans; D008297:Male; D016896:Treatment Outcome
D005938:Glucocorticoids; D006728:Hormones; D019382:Human Growth Hormone