24-25-dihydroxyvitamin-d-3 and Hyperparathyroidism--Secondary

Deficiency of 1,25-dihydroxyvitamin D [1,25(OH)(2)D] and excessive fibroblast growth factor (FGF23) are suggested to be associated with increased mortality in patients with chronic kidney disease (CKD). Generally, 24-hydroxylation has been considered the first step in the degradation pathway of 1,25(OH)(2)D and 25(OH)D. 24,25-dihydroxyvitamin D [24,25(OH)(2)D] was believed to be a degradation product, with no important biological effects. However, some data have accumulated showing that 24,25(OH)(2)D has biological effects on its own. Under conditions of eucalcemia, the synthesis of 24,25(OH)(2)D is increased, and the synthesis of 1,25(OH)(2)D is decreased. In patients with CKD, both high parathyroid hormone levels, which decrease the activity of enzyme CYP24A1 (24-hydroxylase), and high FGF23 levels, which increase the activity of enzyme CYP24A1, were often detected. However, information about 24,25(OH)(2)D levels in these patients is very limited. Whether compensatory changes in levels of FGF23 and 24,25(OH)(2)D in CKD patients are protective or harmful remain unknown issues. Therefore, more studies are needed to identify the nature of the interactions between these molecules and to fully elucidate their clinical significance.

Topics: 24,25-Dihydroxyvitamin D 3; Animals; Fibroblast Growth Factor-23; Fibroblast Growth Factors; Humans; Hyperparathyroidism, Secondary; Kidney Failure, Chronic; Renal Dialysis; Vitamin D Deficiency; Vitamins

We compared the effect of conservative treatment with that of surgical treatment after applying them on secondary hyperparathyroidism patients (2nd HPT) in order to study the application of surgery on 2nd HPT patients. We selected the test subject of 39 maintenance dialysis patients with complications of 2nd HPT. The conservative treatments were; elcitonine administration (40 u x 3/W) (group 1), ipriflavon administration (200 mg x 3/day) (group 2), and pulse treatment (1.25 (OH)2D3 6 micrograms/W) (group 3). For surgical treatment, we adopted total parathyroidectomy with auto-transplantation into the arm (PTX). The transition of serum parathyroid hormone (PTH-C), alkali-phosphatase (ALP), bone scintigraphy of every 6 months, and change of bone mineral content (BMC) were compared to judge the effects of treatments. We measured 1/3, 1/6 radial region with single photon absorptiometry (SPA) and L3 region with dual photon absorptiometry (DPA) to obtain BMC. We were forced to transfer the patients in groups 1 and 2 (conservative treatment) to pulse treatment or PTX as 12 months later they showed increase in serum PTH-C, ALP and significant drop (P less than 0.05) in BMC average change rate (1/3). In group 3 of pulse treatment, though significant decrease in serum ALP (P less than 0.01) was detected for 10 cases out of 12, serum PTH-C was either unchanged or increased for 4 cases with the value of more than 30 ng/ml. Furthermore the average change rate of BMC stayed at the same level.(ABSTRACT TRUNCATED AT 250 WORDS)

Topics: 24,25-Dihydroxyvitamin D 3; Adult; Arm; Bone and Bones; Bone Density; Calcitonin; Chi-Square Distribution; Female; Humans; Hyperparathyroidism, Secondary; Isoflavones; Male; Middle Aged; Parathyroid Glands; Parathyroidectomy; Radionuclide Imaging; Transplantation, Autologous; Transplantation, Heterotopic