Journal of Endocrinological Investigation

, Volume 30, Issue 6, pp 513–516 | Cite as

Impaired parathyroid hormone response to hypocalermic stimuli in a patient with hypomagnesemic hypocalcemia

  • Y. Iwasaki
  • M. Asai
  • M. Yoshida
  • Y. Oiso
  • K. Hashimoto
Case Report


Magnesium (Mg) deficiency sometimes causes hypocalcemia with impaired PTH secretion although the precise mechanism remains unclear. We examined the PTH secretion in response to physiological hypocalcemic stimuli in a patient with hypomagnesemic hypocalcemia. We adopted sodium bicarbonate infusion test, which we recently developed, to evaluate the PTH response to acute decrease in plasma ionized Ca. The results showed that, before Mg replacement and when the patient was mildly hypocalcemic, absolutely no PTH release to hypocalcemic stimuli was observed. In contrast, the plasma Ca was promptly normalized following the start of Mg replacement, and brisk PTH response to hypocalcemic stimuli was obtained during the same test carried out a week after the Mg replacement. The data in this case thus suggest that: a) the acute regulation of PTH release by plasma ionized Ca is lost in the patient with hypomagnesemic hypocalcemia, and b) Mg deficiency itself is likely to be a primary cause of this disorder because the hormone response was clearly restored after short-term Mg replacement alone.


Hypocalcemia hypomagnesemia parathyroid hormone parathyroid gland tetany 


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Copyright information

© Italian Society of Endocrinology (SIE) 2007

Authors and Affiliations

  • Y. Iwasaki
    • 1
    • 2
  • M. Asai
    • 2
  • M. Yoshida
    • 2
  • Y. Oiso
    • 2
  • K. Hashimoto
    • 1
  1. 1.Department of Endocrinology, Metabolism, and Nephrology, Kochi Medical SchoolKochi UniversityKohasu, Oko-cho, NankokuJapan
  2. 2.Department of Medicine, Graduate School of MedicineNagoya UniversityNagoyaJapan

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