Ten weeks of intermittent hypocalcemic stimulation does not produce functional parathyroid hyperplasia

L. E. Mallette, B. W. Hollis, K. Dunn, M. Stinson, J. K. Dunn, E. Wittels, A. M. Gotto

Research output: Contribution to journalArticlepeer-review

3 Scopus citations


Hypocalcemia is a major stimulus for parathyroid hormone secretion and presumably the major cause of parathyroid hyperplasia in chronic hypocalcemic syndromes. We could find no data to indicate what degree, duration, or frequency of hypocalcemia is needed to produce parathyroid hyperplasia in humans. We have monitored the effects of thrice weekly hypocalcemic parathyroid stimulation for 10 weeks. Measurements were made during a study designed to test the feasibility of carrying out a randomized, blinded trial of 'chelation therapy', a widely used but unproven method to treat atherosclerotic symptoms. Eight patients received infusions of disodium ethylenediaminetetraacetic acid (EDTA) and six received placebo infusions thrice weekly for ten weeks. The EDTA infusions (50 mg/hg over three hours) lowered serum ionized calcium at two hours by an average of 0.20 mmol/L and trebled the immunoreactive parathyroid hormone (iPTH) value. Basal serum iPTH, ionized calcium and 1,25-dihydroxyvitamin D values, measured just before the infusion, did not change significantly after 10 weeks of treatment with either EDTA or placebo. The increment in serum iPTH produced by the EDTA-induced hypocalcemia was also unchanged. Lowering ionized serum calcium to values below the normal range three times a week for 10 weeks is not a sufficient stimulus to cause a detectable increase in basal or stimulated parathyroid function.

Original languageEnglish (US)
Pages (from-to)138-141
Number of pages4
JournalAmerican Journal of the Medical Sciences
Issue number3
StatePublished - 1991


  • 1,25dihydroxyvitamin D
  • atherosclerosis
  • hypocalcemia
  • parathyroid hormone
  • parathyroid hyperplasia

ASJC Scopus subject areas

  • Medicine(all)


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