[Parathormone, calcitonin, 25-hydroxycalciferol and bone histology in patients with chronic renal insufficiency].

In 18 patients with chronic renal failure the parathormone (PTH), calcitonin (CT) and 25-OH-D blood levels were estimated before and after an intravenous calcium load. In ten patients the above mentioned biochemical parametres were confronted with histological findings obtained in bone biopsy material. Significantly elevated levels of PTH and CT were found while those of 25-OH-D were normal. Serum PTH decreased after a calcium load. In contrast to healthy persons no increase of serum CT was stated. Significant positive correlations were found between PTH and CT levels in blood serum as well as between the mineralized bone volume and 25-OH-D levels in serum. In addition a significant negative correlation was stated between the osteoid volume and 25-OH-D levels in blood serum. From the results obtained it is concluded, that from estimations of PTH, CT and 25-OH-D in blood serum histological alterations in bone biopsy material from chronic uremic patients can not be predicted. Beside secondary hyperparathyreoidism, relative deficiency of CT and active vitamin D metabolites other factors are also involved in the pathogenesis of renal osteodystrophy.