TRIAL OF CALCIUM SUPPLEMENTATION FOR BONE MINERALIZATION IN JUVENILE RHEUMATOID ARTHRITIS

Pediatric Rheumatology Online Journal → June 2003 → Medical Treatment → Miscellaneous Medical Treatment→ Abstract #67
August 2003 → Bone → Abstract #67

D. J. Lovell,¹ E. H. Giannini,¹ B. Huang,¹ J. V. Ranz,¹ S. L. Kramer,¹ the PENTA Pediatric Rheumatology Group

¹Rheumatology, Cincinnati Children's Hospital Medical Center, Cincinnati, OH, United States

Objectives: To assess the effect on total body bone mineral density (TBBMD) of daily Ca and vit D supplementation for 24 mo in pts with JRA not receiving glucocorticoids. A secondary objective was to determine the effect of supplementation on bone physiology.
Background: Generalized osteopenia in patients with JRA may be attributable to suboptimal dietary intake of Ca and vit D, lowered GI Ca absorption and low bone formation rate.
Methods: Double-blind, randomized, placebo controlled prospective clinical trial to compare the effect on TBBMD, assessed by DXA, of 24 mo of daily oral supplementation of 1000 mg of Ca and 400 IU of vit D versus daily placebo and 400 IU of vit D. Compliance to study medication was measured electronically and by pill count. Main statistical analyses were by longitudinal random-effects modeling.
Results: 198 pts were enrolled; 103 were given Ca (81 F; 22 M) with an overall mean age (yrs) of 11.8; SD 3.1. 95 subjects were given placebo (60 F; 35 M) with an overall mean age of 11.6; SD 3.4. This analysis focuses on the biologically relevant efficacy subset (N=129), defined as those who took study meds for at least 6 mo and who were 80% compliant. Among these, 60 received Ca; 69 were given placebo. 11 (19%) in the Ca group were osteopenic (WHO definition) at baseline, as were 17 (25%) in the placebo group. Mean TBBMD (gm/cm) at baseline was 0.89 for the Ca group, compared to 0.87 for the placebo group. At 24 mo (end of therapy), the TBBMD for the CA group was 0.97 compared to 0.92 for placebo. With adjustment for gender, baseline TBBMD, BMI%, Tanner stage, compliance, and time between visits the final TBBMD was statistically higher in the Ca group compared to placebo (p=.002). Most bone physiology markers were not significantly different between the groups.
Conclusions: These data suggest that osteopenia is prevalent in this population and Ca supplementation increases TBBMD by a small but statistically significant amount over placebo.