Homeostasis and action of parathyroid hormone in normal man and patients with mild renal failure.

Patients with mild renal failure have elevated blood levels of PTH, and acute hypocalcaemia in these patients produced a greater increment in blood PTH than in normal subjects. There was also a delay in the recovery from hypocalcaemia in patients with mild renal failure as compared to normal subjects. The data are consistent with the presence of skeletal resistance to the calcaemic action endogenous PTH in patients with mild renal failure. This abnormality is probably responsible for the hypocalcaemia of patients with renal failure and to the state of secondary hyperparathyroidism in such patients.