The Influence of Plasma Magnesium Concentration on Parathyroid Hormone Secretion

Buckle, Richard M.; Care, A. D.; Cooper, Cary W.; Gitelman, Hillel J.

doi:10.1677/joe.0.0420529

Cited by 144 publications

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“…Impaired secretion of PTH caused by reduction in serum Mg levels has been thought to be one of the major mechanisms by which hypocalcemia develops in Mg deficiency [3][4][5][6][7]. PTH secretion is known to be affected by extracellular Mg in vitro [24] and in vivo [25,26]. Quitterer et al have revealed that PTH secretion was blocked independently of the extracellular Ca 2+ concentration in primary human parathyroid cells, when Mg was decreased [27].…”

Section: Discussionmentioning

confidence: 99%

A Case of Magnesium Deficiency Associated with Insufficient Parathyroid Hormone Action and Severe Osteoporosis

et al. 2007

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Abstract. The relationship between osteoporosis and magnesium (Mg) deficiency is still controversial. Here we report a case of an 82-year-old woman with a giant adenomatous goiter and severe osteoporosis with multiple vertebral fractures, whose clinical course indicated that her osteoporosis was probably due to Mg deficiency. She visited our hospital for treatments of tetany. Laboratory data showed the existence of hypomagnesemia, hypocalcemia, hypokalemia, vitamin D deficiency, and slightly elevated intact PTH. Intravenous administration of Mg not only improved these electrolyte abnormalities but also increased serum levels of intact PTH, bone formation markers, 1,25-dihydroxyvitamin D, as well as bone resorption markers in the urine, and lowered urinary phosphate reabsorption. Hypomagnesemia on admission seemed to arise from long-lasting poor food intake and malnutrition, because it improved after the disappearance of dysphagia with a goiter resection. After the operation, BMD values at the lumbar spine and femoral neck obviously increased during 6 months of Mg supplementation without any specific therapies for osteoporosis. Mg deficiency in this case seemed to cause impaired secretion of PTH from the parathyroid and the refractoriness of bone and kidney to the hormone, which led to the suppression of both bone remodeling and renal vitamin D production. These processes were probably linked to her severe osteoporosis, which was reversed by Mg supplementation. SERUM calcium levels are normally regulated within a relatively narrow range by the parathyroid gland through a negative feedback mechanism: Increased secretion of parathyroid hormone (PTH) by a fall in blood calcium levels enhances the mobilization of calcium, mainly by bone resorption, and then calcium levels are rapidly restored. Chronic magnesium (Mg) deficiency would result in hypocalcemia [1, 2], because of the impairment of PTH secretion [3][4][5][6][7] and/ or resistance of target organ to PTH action [4,6,8].Previous studies have demonstrated that serum PTH concentration was suppressed in patients with hypomagnesemia [4,5], and Mg substitution therapy enhanced PTH secretion and reversed PTH target-organ resistance, and thus serum calcium concentration returned to normal within several days [4,7]. In addition, Mg deficiency could inhibit the synthesis of 1,25-dihydroxy vitamin D (1,25(OH) 2 D) [9][10][11] as well as its action on bone [11]. Accumulating data have shown that a long-term Mg deficiency and resulting hypomagnesemia could cause osteoporosis and bone fractures through these dysfunctions of PTH and vitamin D action [12,[13][14][15][16][17][18][19]. However, other studies have shown no relationship between Mg deficiency and osteoporosis [20][21][22], and it still seems to be controversial whether or not Mg deficiency could cause osteoporosis. Here we report a patient with a giant adenomatous goiter and severe osteoporosis exhibiting hypomagnesemic hypocalcemia, whose osteoporosis was reversed by Mg supplementation with chronological improv...

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Section: Discussionmentioning

confidence: 99%

A Case of Magnesium Deficiency Associated with Insufficient Parathyroid Hormone Action and Severe Osteoporosis

et al. 2007

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“…In contrast, other data suggest that a reduction in the serum level of magnesium may directly stimulate the secretion of parathyroid hormone: thus, perfusion of the parathyroid glands, in vitro, with blood containing a low concentration of magnesium causes release of PTH (32), and elevated levels of plasma PTH have been described in two patients with magnesium depletion (13,33). Also, hyperplasia of the parathyroid glands has been described in magnesium-depleted calves (6).…”

Section: Studies On Mechanisms Of Hypocalcemia Of Magnesium Depletionmentioning

confidence: 99%

Studies on Mechanisms of Hypocalcemia of Magnesium Depletion

Reddy¹,

Coburn²,

Hartenbower³

et al. 1973

J. Clin. Invest.

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A B S T R A C T Studies were carried out to evaluate the mechanism of hypocalcemia in magnesium depletion. Day old chicks fed a magnesium deficient diet developed marked hypocalcemia, with a direct relation between serum calcium (y) and magnesium (x): y = 2.68 x + 4.24, r = 0.84 (both in mg/100 ml). Injections of parathyroid extract that increased serum calcium 2-3 mg/100 ml in normals had no effect in Mg-depleted birds. Very large dietary supplements of calcium or vitamin D3 increased mean serum calcium only from 5.3 to 7.7 and 7.8 mg/100 ml, respectively, while a normal magnesium diet for 3 days increased calcium from 5.3 to 9.9 mg/100 ml despite absence of dietary calcium. Intestinal calcium transport, studied in vitro, and the calcium concentration of the carcass was significantly increased in magnesium-depleted chicks, making it unlikely that reduced intestinal absorption of calcium caused the hypocalcemia. In magnesium-deficient chicks, the bone content of magnesium was decreased by 74%, the calcium content was unchanged, and the cortical thickness of bone was markedly increased. After 3 days of magnesium-repletion, cortical thickness was reduced with increased endosteal resorption. There INTRODUCTIONHypocalcemia has been reported to be associated with magnesium depletion in a number of species, including rats fed a low calcium diet (1, 2), sheep (3), pigs (4), calves (5, 6), dogs (7,8), monkeys (9), and man (10)(11)(12)(13)(14) In the present study, a model of experimental magnesium depletion in the chick is described, and various factors which might be involved in the development of hypocalcemia were evaluated. METHODS White leghorn cockerels obtained 1 day after hatching (through courtesy of H & N Hatchery, Inc., Riverside, Calif.) were housed in electric brooders. Chicks were chosen as experimental models because their diet can be controlled immediately after hatching, permitting the rapid development of magnesium depletion. In addition, chickens are known to be sensitive to parathyroid extract (15), thus providing a suitable model to evaluate responsiveness to the hormone. Furthermore, considerable information is available concerning calcium homeostasis in this species.They received a synthetic diet, modified from that of Fox and Briggs (16), and distilled water ad libitum. The diet, as originally described, contained 0.060% magnesium, an amount considered the optimal quantity needed by growing chicks (16,17). With deletion of supplemental magnesium and calcium salts, the basic diet was found by analysis to contain 0.004% magnesium and 0.005% calcium. In preparation of certain diets discussed below, magnesium sulfate was added providing 0.010, 0.020, or 0.060% magnesium.Unless noted otherwise, the diets were supplemented to contain 1.2% calcium, an amount higher than the 0.7-0.8% usually provided, 0.8% phosphorus, and 80 IU of vitamin D3 (cholecalciferol) /100 g.For purposes of establishing the appropriate dietary magnesium for studying magnesium depletion in the fowl, preliminary experiments were ...

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“…The higher ROV% in the low-Mg, low-parity group may therefore indicate a higher bone-formation rate than in the high-Mg, low-parity cows. Magnesium influences the rate of secretion of parathyroid hormone (PTH) both in vivo (1,6) and in vitro (33). The data of Buckle et al (6) showed that an acute reduction in plasma Mg concentration stimulated PTH secretion, probably owing to reduced inhibition by magnesium, since magnesium, like calcium, suppresses PTH concentration when its concentration increases (6,33).…”

mentioning

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“…Magnesium influences the rate of secretion of parathyroid hormone (PTH) both in vivo (1,6) and in vitro (33). The data of Buckle et al (6) showed that an acute reduction in plasma Mg concentration stimulated PTH secretion, probably owing to reduced inhibition by magnesium, since magnesium, like calcium, suppresses PTH concentration when its concentration increases (6,33). In contrast, other studies have shown that severe depletion of Mg, leading to chronic hypomagnesaemia, can impair both the rate of secretion of PTH in vitro (33) and in vivo (1,15) and the ability of PTH to act on the target tissues, bone and kidney (15).…”

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Effects of a deficient magnesium supply during the dry period on bone turnover of dairy cows at parturition

Mosel

Klooster

Wouterse

1991

Veterinary Quarterly

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SUMMARY. The bone activity and bone mineral content in rib bones resected from 33 dairy cows between 3 and 8 h after parturition were measured, and the effects upon them of a deficient supply of dietary magnesium (Mg) during the last seven weeks of pregnancy were studied. The cows were fed a diet containing either 0.22% magnesium (low Mg) or 0.82% magnesium (high Mg) in the dry matter (DM), and the potassium content of both rations was increased to approximately 4.1% in the DM to reduce the absorption of magnesium. In the cows fed the low-Mg diet a fall in plasma Mg concentration was observed In the low-Mg, low-parity cows the plasma Mg concentrations at parturition were higher than in the low-Mg, high-parity cows, i.e. 0.83 mmol/l and 0.54 mmo1/1, respectively. After parturition four cows in the lowMg, high-parity group showed clinical signs of hypocalcaemia but none of the other groups did so. The bone formation in low-parity cows was significantly (P < 0.05) affected by Mg supply, with higher percentages of both trabecular surface covered by osteoid and osteoid volume in the low-Mg group. In the high-parity cows no significant differences in bone formation were found between the low-and high-Mg groups. An inadequate Mg supply resulted in a significantly (P < 0.05) higher Ca content in the bone ash of low-parity cows and a significantly (P < 0.05) higher bone ash percentage in the bone of high-parity cows.

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The Influence of Plasma Magnesium Concentration on Parathyroid Hormone Secretion

Cited by 144 publications

References 0 publications

A Case of Magnesium Deficiency Associated with Insufficient Parathyroid Hormone Action and Severe Osteoporosis

A Case of Magnesium Deficiency Associated with Insufficient Parathyroid Hormone Action and Severe Osteoporosis

Studies on Mechanisms of Hypocalcemia of Magnesium Depletion

Effects of a deficient magnesium supply during the dry period on bone turnover of dairy cows at parturition

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