Dynamic tests of parathyroid hormone secretion using hemodialysis and calcium infusion cannot be compared

What Was Tested

This clinical trial paper looks at Parathyroid Hormone (PTH 1-84).

Extracellular Ca++ concentration [Ca++] and parathormone (PTH) are related by a sigmoidal function.

The set point of the control system is the [Ca++] that produces a half-maximal inhibition of PTH secretion.

Who Took Part

The study group was 12 patients.

The age groups tagged for this paper are teenagers, adults and middle-aged adults, both men and women.

The researchers performed dynamic tests of PTH secretion in 12 patients with CRF and SHP during either HD or INF.

How the Study Was Run

The researchers investigated whether the way [Ca++] is varied [hemodialysis (HD) or calcium gluconate/sodium citrate infusions (INF)] and the way the curve is constructed (four-parameter model or adapted four-parameter, created by Felsenfeld) could influence this set point.

Both the four-parameter model or adapted four-parameter methods were used, creating four combinations: (a) hypocalcemia and hypercalcemia induced during HD, calculated by Brown's formula (HDB); (b) hypocalcemia and hypercalcemia induced during HD, calculated by Felsenfeld's formula (HDF); (c) hypocalcemia and hypercalcemia induced during infusion, calculated by Brown's formula (INFB); and (d) hypocalcemia and hypercalcemia induced during infusion, calculated by Felsenfeld's formula (INFF).

What Was Measured

Whether or not this set point is abnormal in patients with chronic renal failure (CRF) and secondary hyperparathyroidism (SHP) is controversial.

Topics PubMed links to this paper include Calcium, Calcium Gluconate, Citrates, Hyperparathyroidism, Secondary, Hypocalcemia, Kidney Failure, Chronic and Linear Models.

What This Means in Plain Language

This is a clinical trial of Parathyroid Hormone (PTH 1-84) in 12 patients.

With fewer than 40 people, it is a small study, so it is better read as an early signal for further research than as a settled answer.

The abstract goes on to report its results in about 5 sentences; this page does not restate them, so read the paper for the findings and their limits.

The publication is from 1999 (Kidney international), a journal based in United States.

More context: the Parathyroid Hormone (PTH 1-84) compound page, all human trials.