Estrogen replacement decreases the set point of parathyroid hormone stimulation by calcium in normal postmenopausal women

Boucher, Annie; D'Amour, P; Hamel, Lucie; Fugere, P; Re, Mancini; Lepage, Raymond; Ste-Marie, Line

doi:10.1016/0378-5122(89)90248-x

Cited by 16 publications

(19 citation statements)

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“…A slight difference in parathyroid cell sensitivity to calcium between postmenopausal women with PHP and controls is not excluded but is likely overcome by the rise of 0.9 mmol/l in plasma calcium levels during the suppression testing. Furthermore, PTH secretion appeared similarly suppressed by increasing calcium level in treated and non-treated women (36). Another potential confounding variable is vitamin D concentration.…”

Section: Discussionmentioning

confidence: 99%

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Evaluation of a standardized short-time calcium suppression test in healthy subjects: interest for the diagnosis of primary hyperparathyroidism

et al. 2007

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Objective: The diagnosis of primary hyperparathyroidism (PHP) can be difficult in patients with normal plasma calcium or parathyroid hormone (PTH) levels. We perfected a standardized short-time i.v. calcium loading test in healthy controls (HC) and compared the results with those of patients with PHP. Methods: Sixteen HC received 0.33 mmol/kg calcium gluconate intravenously for 3 h. Plasma calcium and serum PTH levels (assayed with immunoluminescent sandwich methods) were measured before, at the end of the infusion and 3 h later. Results were compared with those of 16 PHP patients. Results: In HC, basal total plasma calcium (meanGS.E.M.) was 2.33G0.02 mmol/l. At the end of calcium loading, calcemia reached 3.21G0.05 mmol/l and decreased to 2.94G0.08 mmol/l 3 h later. In PHP patients, basal plasma calcium was 2.54G0.03 mmol/l and reached similar values as in HC during the testing. Basal serum PTH levels were 32.5G3.3 ng/l in HC and 86.9G6.3 ng/l in PHP. At the end of calcium loading, they dropped to 8.8G0.6 ng/l (HC) and to 31.4G4.2 ng/l (PHP). Three hours later, they were 11.6G0.8 and 39.8G4.0 ng/l respectively. There was a cut-off in serum PTH values between the two groups at the end of calcium loading and 3 h later. Conclusion: The standardized short-time PTH suppression test appears reliable to differentiate healthy subjects from PHP whose serum PTH levels remain O14 and O23 ng/ml respectively at the end of loading and 3 h later. This well-tolerated and easily performed test could be used for the diagnosis of PHP in patients suspected for the disease despite the normality of some basal biological markers.

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Section: Discussionmentioning

confidence: 99%

“…Such a plasma calcium level is high enough to suppress normal parathyroid secretion (36). Half-lives of circulating 1-84 and 7-84 PTH are 3-5 and 10 min respectively (37,38).…”

Section: Discussionmentioning

confidence: 99%

Evaluation of a standardized short-time calcium suppression test in healthy subjects: interest for the diagnosis of primary hyperparathyroidism

et al. 2007

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“…This result suggests a reduced sensitivity to calcium in the lithium-treated group. In a study in healthy postmenopausal women, 23 wk of estrogen treatment reduced the ionized calcium concentration and decreased the set point of calcium, shifting the PTH-calcium curve to the left even though basal and maximal PTH values did not change (100). A confounding variable in that study was that PTH was measured with a carboxy-terminal assay.…”

Section: Set Point Of Calciummentioning

confidence: 99%

Dynamics of Parathyroid Hormone Secretion in Health and Secondary Hyperparathyroidism

Felsenfeld

Rodríguez

Aguilera–Tejero

2007

Clinical Journal of the American Society of Nephrology

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This review examines the dynamics of parathyroid hormone secretion in health and in various causes of secondary hyperparathyroidism. Although most studies of parathyroid hormone and calcium have focused on the modification of parathyroid hormone secretion by serum calcium, the relationship between parathyroid hormone and serum calcium is bifunctional because parathyroid hormone also modifies serum calcium. In normal animals and humans, factors such as phosphorus and vitamin D modify the basal parathyroid hormone level and the maximal parathyroid hormone response to hypocalcemia. Certain medications, such as lithium and estrogen, in normal individuals and sustained changes in the serum calcium concentration in hemodialysis patients change the set point of calcium, which reflects the serum calcium concentration at which parathyroid hormone secretion responds. Hypocalcemia increases the basal/maximal parathyroid hormone ratio, a measure of the relative degree of parathyroid hormone stimulation. The phenomenon of hysteresis, defined as a different parathyroid hormone value for the same serum calcium concentration during the induction of and recovery from hypo-and hypercalcemia, is discussed because it provides important insights into factors that affect parathyroid hormone secretion. In three causes of secondary hyperparathyroidism-chronic kidney disease, vitamin D deficiency, and aging-factors that affect the dynamics of parathyroid hormone secretion are evaluated in detail. During recovery from vitamin D deficiency, the maximal parathyroid hormone remains elevated while the basal parathyroid hormone value rapidly becomes normal because of a shift in the set point of calcium. Much remains to be learned about the dynamics of parathyroid hormone secretion in health and secondary hyperparathyroidism. T his review examines the dynamics of parathyroid hormone (PTH) secretion in health and in various causes of secondary hyperparathyroidism with an emphasis on chronic kidney disease (CKD). For better understanding of factors that affect PTH secretion, the PTH-calcium relationship is evaluated with respect to (1) PTH secretion in the baseline state (basal PTH) and its sensitivity to the serum calcium concentration; (2) the maximal PTH response to hypocalcemia and factors that have been reported to modify the maximal PTH response to hypocalcemia; (3) shifts in the set point of calcium for PTH secretion in normal individuals as a result of treatment with medications such as lithium and estrogen and in hemodialysis patients during sustained changes in the serum calcium concentration; (4) the dynamics of PTH secretion in the secondary hyperparathyroidism of CKD, vitamin D deficiency, and aging; and (5) the phenomenon of hysteresis, defined as a different PTH value for the same serum calcium concentration during the induction of and recovery from both hypo-and hypercalcemia. A focus on hysteresis is justified because it provides important insights into how PTH secretion is modified by rate and directional changes in the serum c...

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“…The effect of estradiol on basal hypercalcemia described by other authors (Boucher et al, 1989;Gallagher & Nordin, 1975) was not confirmed. Lower increment of calcemia after estrogen treatment attained by administration of the same calcium load as in the control test does not exclude the possibility that estrogen alters body distribution of calcium.…”

Section: Hyperparathyroidism Parathyroid Hormone and Steroids In Minmentioning

confidence: 62%

Hyperparathyroidism in Hemodialyzed Patients – Relation to Melatonin and Reproductive Hormones Before and After Parathyroidectomy

Kancheva¹,

Žofková²,

Hill³

et al. 2012

Hyperparathyroidism

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Estrogen replacement decreases the set point of parathyroid hormone stimulation by calcium in normal postmenopausal women

Cited by 16 publications

References 0 publications

Evaluation of a standardized short-time calcium suppression test in healthy subjects: interest for the diagnosis of primary hyperparathyroidism

Evaluation of a standardized short-time calcium suppression test in healthy subjects: interest for the diagnosis of primary hyperparathyroidism

Dynamics of Parathyroid Hormone Secretion in Health and Secondary Hyperparathyroidism

Hyperparathyroidism in Hemodialyzed Patients – Relation to Melatonin and Reproductive Hormones Before and After Parathyroidectomy

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