Abstract
Parathyroidectomy (PTX) was performed in seven hemodialysis patients with secondary hyperparathyroidism. To evaluate the efficacy of PTX in producing incremental changes in bone mineral density (BMD), we measured BMD of the lumbar vertebrae (L2-L4) one, three and six months after PTX. BMD was also determined in the proximal femur (femoral neck, trochanteric and intertrochanteric and Ward's triangle) and the radius three and six months after PTX. DEXA was utillized, using the QDR 1000 (Hologic Inc. Waltham, Mass. USA).
Significant BMD increases were seen in the L2-4 vertebrae both three and six months after PTX, which effectively and markedly reduced intact parathyroid hormone levels (Allegro) from 1, 060pg/ml to the normal range. This increment in BMD was compatible with previous reports using dual photon absorptiometry. As for the proximal femur, significant elevations of BMD were also observed in each region except the femoral neck on the right side of the body six months after PTX. In contrast, it was found that there was a decreasing trend in BMD, which was detected as an increase in each area after three months, on the left side of the body six months after PTX. Some discrepancies in BMD increases were observed between the right and left sides. However, the BMD of radii did not reveal any significant increase, which was not compatible with the data of previous reports using single photon absorptiometry.
It was found that the increasing rates of BMD seemed to be higher in the lumbar vertebrae than in the proximal femur and were lowest in the radius. The elevation of BMD in both lumbar vertebrae and proximal femurs, without any incremental change in the BMD of radii, suggest that BMD increases more rapidly in the spongiosa than in the cortical bone after PTX.
