Bone health in children and adolescents with juvenile idiopathic arthritis and the influence of short-term physical exercise.

Purpose: To study bone mineral density (BMD) in 54 children and adolescents with juvenile idiopathic arthritis before and after a short-term exercise program.

Methods: Fifty-four children, 41 girls and 13 boys, median age 13.9 years, participated in a 12-week exercise program, with 33 children in an exercise group. The program consisted of one hundred 2-footed jumps with a rope and standardized muscle strength exercise. Both BMD and bone mineral content were assessed with dual-energy x-ray absorptiometry (DXA) and DXA Laser Calscan for the heel at the start and after 3 and 6 months.

Results: The study group had BMD measurements within the reference range compared with normative data with Z score at start. Bone mineral density values in total body, but not Z score, increased significantly (P = .012) in the exercise group.

Conclusions: The study group had BMD measurements within the reference range. Twelve weeks of exercise increases BMD in children with juvenile idiopathic arthritis.