[Parathyroid function in patients on chronic intermittent hemodialysis (author's transl)]

In three groups of hemodialysis patients the effects of an acute elevation of the serum calcium concentration on the predialysis parathyroid hormone concentration was studied. In the first group (13 patients) the predialysis parathyroid hormone (PTH) concentrations were normal, in the second group (11 patients) slightly elevated, in the third group (5 patients) highly elevated. Calcium was determined by atomic absorption-spectrophotometry, PTH by radioimmunological methods. In hemodialysis patients with normal predialysis PTH concentrations a correlation between the serum calcium concentration and the serum PTH concentration could not be detected. In hemodialysis patients with slightly as well as with highly elevated predialysis PTH concentrations a significant, linear, negative correlation was found between the calcium and the PTH concentration. This correlation, however, was only strong within groups of similar parathyroid hyperfunction. If instead of the absolute PTH concentration calcium is correlated with the changes of the PTH concentration in per cent, a strong correlation between these two parameters can be detected, it is independent of the degree of parathyroid hyperfunction.