Renal Tubular Maximum Reabsorptive Capacity for Phosphate in Patients with Primary Hyperparathyroidism before and after Operation

Summary

A determination was made of the renal tubular maximum reabsorptive capacity for phosphate (expressed as a function of the glomerular filtrate) in 33 patients with primary hypercalcaemic hyperparathyroidism and 30 control normal subjects. The difference between patients and controls for the maximum renal tubular reabsorptive capacity for phosphate (patients 0.526 ± 0.16 mmol/1, controls 1.010 ± 0.14 mmol/1) was highly significant (p < 0.001). Successful removal of a single parathyroid adenoma in 19 patients was associated with a highly significant rise in the renal tubular maximum reabsorptive capacity for phosphate (1.005 ± 0.21 mmol/1, p < 0.001). We did not find any correlation between the renal tubular maximum reabsorptive capacity for phosphate and serum immunoreactive PTH level. Low renal tubular maximum reabsorptive capacity for phosphate in the presence of hypercalcaemia is highly suggestive of primary hyperparathyroidism.

Key words

Hyperparathyroidism - iPTH - Renal tubular capacity - Phosphate