GROWTH-RETARDATION AND BONE LOSS AS DETERMINANTS OF AXIAL OSTEOPENIA IN JUVENILE CHRONIC ARTHRITIS

The aim of the study was to evaluate the significance of growth retard ation and bone loss as determinants of axial osteopenia in children wi th juvenile oligo- and poryarthritis. Bone mineral density (BMD), bone size (width), and bone volumetric density (BMDvol) were determined by dual x-ray absorptiometry at the lumbar spine and femoral neck in chi ldren with juvenile oligoarthritis (n=36), polyarthritis (n=75), and a group of healthy children (n=66). Comparison of measurements showed t hat children with juvenile polyarthritis had a significantly reduced B MDvol (p<0.05) and bone size (p<0.01) at the lumbar spine, resulting i n a 10.5% decrease in BMD (p<0.001). At the femoral neck, the 16% decr ease in BMD (p<0.001) was attributed only to a decrease in BMDvol (p<0 .001). In juvenile oligoarthritis, the development of osteopenia was n onsignificant except at the femur, whew the 6.6% decrease of BMD was a ssociated with significant decrease of BMDvol (p<0.05). The bone loss associated with juvenile chronic arthritis appears to develop with con current growth retardation at the spine, but without detectable growth retardation at the femoral neck.