Gunhild Lien

Young adults with juvenile arthritis in remission attain normal peak bone mass at the lumbar spine and forearm

OBJECTIVE To assess the impact of disease activity on acquired peak bone mass and bone turnover in young adult patients with either persistent juvenile arthritis (JA) or a history of JA (JA in remission). METHODS Two hundred twenty-nine patients with JA were studied after a mean +/- SD of 15.6 +/- 2.4 years in women and 14.9 +/- 2.1 years in men since disease onset. One hundred forty-five women and 84 men were over the age of 20 at the time of examination (mean +/- SD age 24.9 +/- 2.9 years for women and 25.2 +/- 3.1 years for men). Forty-one healthy women (mean +/- SD age 27.4 +/- 3.1 years) and 55 healthy men (mean +/- SD age 25.7 +/- 3.1 years) served as a reference group. Bone mineral density (BMD) was analyzed by dual x-ray absorptiometry. Serum osteocalcin concentrations and urinary concentrations of deoxypyridium (D-Pyd) were measured. Linear regression analyses were performed to evaluate the impact of disease on BMD. RESULTS Patients with persistent disease had significantly lower BMD compared with healthy subjects (P < 0.001 for women at all measured sites and for men at the femoral neck and total body; P < 0.05 for men at the radius and lumbar spine). Of the patients with a history of JA, only women had significantly lower BMD at the femoral neck and total body (P < 0.05). Patients with persistent JA had significantly more osteopenia and osteoporosis than healthy subjects, while patients with a history of JA had more frequent osteopenia only in the total body. Weight, urinary concentration of D-Pyd, and belonging to the patient group significantly affected BMD at all measured sites in the entire study population, while analysis of all patients found that only the number of months taking corticosteroids significantly affected BMD at all measured sites. However, the impact of the variables differed from site to site. CONCLUSION Our findings imply that most young adults with JA attain the same BMD as healthy subjects if the disease goes into remission, while young adults with active disease have increased risk for osteopenia and osteoporosis.

Serum levels of osteoprotegerin and receptor activator of nuclear factor -κB ligand in children with early juvenile idiopathic arthritis: a 2-year prospective controlled study

BackgroundThe clinical relevance of observations of serum levels of osteoprotegerin (OPG) and receptor activator of nuclear factor -κB ligand (RANKL) in juvenile idiopathic arthritis (JIA) is not clear. To elucidate the potential role of OPG and RANKL in JIA we determined serum levels of OPG and RANKL in patients with early JIA compared to healthy children, and prospectively explored changes in relation to radiographic score, bone and lean mass, severity of the disease, and treatment.MethodsNinety children with early oligoarticular or polyarticular JIA (ages 6-18 years; mean disease duration 19.4 months) and 90 healthy children individually matched for age, sex, race, and county of residence, were examined at baseline and 2-year follow-up. OPG and RANKL were quantified by enzyme-immunoassay. Data were analyzed with the use of t-tests, ANOVA, and multiple regression analyses.ResultsSerum OPG was significantly lower in patients than controls at baseline, and there was a trend towards higher RANKL and a lower OPG/RANKL ratio. Patients with polyarthritis had significantly higher increments in RANKL from baseline to follow-up, compared to patients with oligoarthritis. RANKL was a significant negative predictor for increments in total body lean mass. Patients who were receiving corticosteroids (CS) or disease-modifying antirheumatic drugs (DMARDs) at follow-up had higher OPG/RANKL ratio compared with patients who did not receive this medication.ConclusionsThe data supports that levels of OPG are lower in patients with JIA compared to healthy children, and higher levels of RANKL is associated with more serious disease. RANKL was a significant negative predictor of lean mass in patients with JIA. The OPG/RANKL ratio was higher in patients on DMARDs or CS treatment.