Growth velocity and interleukin 6 concentrations in juvenile idiopathic arthritis.
OBJECTIVE
.To evaluate associations of growth velocity with inflammatory markers and cumulative dose of glucocorticoid in a cohort of patients with juvenile idiopathic arthritis (JIA) followed during 1 year.


METHODS
Seventy-nine patients were evaluated. Disease activity was evaluated by a pediatric rheumatologist. Anthropometric data were classified according to the World Health Organization standards. Tanner growth velocity curves were used; values below the Z-score < or = -2 were considered low growth velocity. Serum concentrations of interleukin 6 (IL-6) were measured by ELISA, and values > 1 pg/ml were considered elevated.


RESULTS
The prevalence of low growth velocity was 25.3%, and it was associated with active disease on followup visit, elevated IL-6, erythrocyte sedimentation rate and C-reactive protein, and higher cumulative glucocorticoid doses. In the multiple linear regression with growth velocity as the dependent variable, only elevated IL-6 level was independently and negatively associated with growth velocity.


CONCLUSIONS
Low growth velocity is highly prevalent in children with JIA. Elevated IL-6 levels seem to have an important negative influence on growth in these children, while total glucocorticoid exposure appears to be a secondary factor.
Division of Rheumatology, Hospital de Clínicas de Porto Alegre, Universidade Federal do Rio Grande do Sul, Porto Alegre, RS, Brazil.
Leticia S
LS
Souza
Sandra H
SH
Machado
Claiton V
CV
Brenol
Joao Carlos T
JC
Brenol
Ricardo M
RM
Xavier
D000293:Adolescent; D000886:Anthropometry; D001171:Arthritis, Juvenile / Q000188:drug therapy / Q000453:epidemiology* / Q000276:immunology*; D015415:Biomarkers / Q000097:blood; D002648:Child; D005260:Female; D005938:Glucocorticoids / Q000627:therapeutic use; D006130:Growth Disorders / Q000453:epidemiology* / Q000276:immunology*; D006801:Humans; D015850:Interleukin-6 / Q000097:blood*; D016014:Linear Models; D008297:Male; D015995:Prevalence; D011627:Puberty
D015415:Biomarkers; D005938:Glucocorticoids; C508600:IL6 protein, human; D015850:Interleukin-6