Standardization for Dual Energy X-ray Absorptiometry / 대한내과학회지

OBJECTIVES: Bone densitometry is a current method for evaluating skeletal status, assessing osteoporosis, and determining fracture risk. DEXA has rapidly become a dominent method for evaluating skeletal status. But the comparison of patient data among different DEXA scanners is complicated because the instruments show differences in scanner design, bone mineral calibration, and analysis algorithms. The purpose of this study is making standardization of DEXA and comparability among different DEXA system. METHODS: Posteroanterior lumbar spine (L2-IA) measurements of healthy 83 racially homogenous Korean women, age 38-66 years (mean +/- 516, range of BMD 0.624-1.574g/cm) were obtained on a Lunar DPX-L, a Hologic QDR-2000, and a Norland XR-36. All sujects had no spinal deformities, ostophytes, fracture and scoliosis on thoracolumbar spinal X-ray. We performed the measurement of BMD in each subjects with different three scanners at the same time. RESULTS: The results of cross-calibration spinal BMD (L2-4, g/cm2) in patient study (r2=0.972-0.974); Lunar DPX-L=(1.149 X Hologic)+0.008=(1.022 X Norland)+0.137, Hologic QDR-2000=(0.847 X Lunar)+0.019= (0.876 X Norland)+0.124, and Norland XR-36=(0.954 X Lunar)-0.107=1.110 X Hologic)-0.113. The average absolute difference in patients` spinal BMD values (L2-L4) between Lunar and Hologic was 0.146g/cm2 (14%); it was 0.156g/cm2 (15%) between Lunar and Norland and 0.010g/cm2 (1%) between Hologic and Norland. CONCLUSIONS: The formula of this cross-calibration shows good correlation. We conclude that it is possible to compare the different spinal BMD values obtained on the different DEXA scanners.

Changes of Bone Turnover Markers after Treatment with Growth Hormone Therapy in Children with Growth Retardation / 대한내분비학회지

The effects of growth hormone(GH) deficiency and recombinant human GH replacement(0.5IU/kg per week) on bone mineral metabolism in 21GH-deficiency children were studied. All children had significantly reduction of bone density(Z score;-1.4+-0.71). After 1 month of therapy, the levels of serum insulin-like growth factor 1(IGF-1), osteocalcin(OC) and carboxyterminal propeptede of type 1 procollagen(PICP) were significantly elevated. But IGFBP-3 were not shown to change significantly. The changes in serum levels of PICP during the first month of recombinant human GH treatment were positively related to growth velocity, whereas the changes in IGF-1 and OC during the first month of therapy were not. We conclude that the recombinant human GH treatment caused significant modifications of mineral metablism and that the measurement of the changes of biochemical markers of bone metablism espacially PICP may be a useful tool in prediction improved growth velocity during long term GH replacement therpy.