Changes in markers of bone turnover and inflammatory variables during alendronate therapy in pediatric patients with rheumatic diseases

OBJECTIVE: Alendronate treatment for 12 months in pediatric patients with rheumatic diseases and secondary low bone mass was reported to result in a substantial increase in bone mineral density (BMD). In this study, we evaluated the changes in bone metabolism and disease activity markers in 45 patients ages 5 to 18 years (31 female, 14 male) with rheumatic diseases treated with alendronate for 12 months. METHODS: Variables analyzed included demographic and anthropometric data, biochemical markers of bone metabolism, disease activity indexes, and BMD values. For all variables, the differences between levels at baseline and at 12 months were calculated; correlations between the variables and between the BMD variation over 12 months and baseline levels of the different variables were also evaluated. RESULTS: There was a statistically significant decrease of both bone resorption and bone formation markers over the 12 month treatment period. By contrast, no disease activity index changed significantly over one year. BMD Z score change over one year did not correlate with erythrocyte sedimentation rate, matrix metalloproteinase-3, interleukin 6, or C-reactive protein variations over the same period. CONCLUSION: These results support the conclusion that alendronate treatment is accompanied by a reduction of bone turnover in pediatric patients and that the observed BMD increase is not secondary to a reduction of inflammatory activity.