COMPARISON BETWEEN SPINAL AND RADIAL BONE-MINERAL DENSITY IN CHILDRENMEASURED BY X-RAY ABSORPTIOMETRY

Several studies have analyzed the correlation between axial bone miner al density (BMD) measured by dual X-ray absorptiometry (DXA) and growt h parameters, However, little is known about the growth-related change s in appendicular BMD measured by this technique. We used DXA to measu re BMD in the lumbar spine (L1-L4) and distal radius in 121 normal gro wing children (69 boys, 52 girls), aged 3 to 18 yr, Both lumbar and ra dius BMD showed a steady increase with age and a steeper increment dur ing puberty, There was a good correlation between spinal and radial BM D (r=0.83; p<0.001) and both were highly correlated with growth parame ters; their respective correlation coefficients did not differ signifi cantly for chronological age (r=0.70 vs 0.80), weight (r=0.77 vs 0.76) , height (r=0.73 vs 0.79), body surface (r=0.78 vs 0.80), body mass in dex (r=0.54 vs 0.49) and bone age (r=0.77 vs 0.79). By multiple regres sion analysis the best predictors for spinal BMD were bone age, pubert al stage and weight, while for radial BMD the best predictors were chr onological age and weight, We have shown that the measurement of BMD b y DXA at distal radius, an easily accessible bone, has a correlation w ith growth parameters as good as lumbar spine BMD measurements in chil dren.