Maire Lubi, Kaia Tammiksaar, Svetlana Matjus, Eero Vasar, Vallo Volke, Magnesium Supplementation Does Not Have an effect on Blood Calcium Stage in Handled Hypoparathyroid Sufferers, The Journal of Medical Endocrinology & Metabolism, Quantity 97, Problem 11, 1 November 2012, Pages E2090–E2092, https://doi.org/10.1210/jc.2012-2301
Hypoparathyroidism is at the moment handled utilizing a mix of calcium (Ca) and vitamin D analog. Nonetheless, a number of research have demonstrated the feasibility of therapy of this situation with PTH fragment 1–34 as a extra physiological possibility (1–3). The primary downside with vitamin D therapy is elevated calciuresis (3), presumably resulting in hostile renal outcomes. Thus, vitamin D therapy is efficient at sustaining plasma Ca ranges however can’t change all of the physiological results of PTH.
A number of observational and experimental research have demonstrated that magnesium (Mg) is a crucial regulator within the homeostasis of Ca metabolism (4). It’s well-known that Mg deficiency could result in vital hypocalcemia that’s proof against Ca therapy (5, 6). Nonetheless, the interrelationship between Ca and Mg ranges will not be simple. Thus, the administration of Mg iv resulted in a lower in serum Ca ranges (7, 8). In the meantime, underneath physiological circumstances Mg supplementation didn’t have an effect on the intestinal absorption of Ca (9). Mg appears to be concerned at completely different ranges of Ca homeostasis as a result of hypomagnesemia not solely impairs the secretion of PTH however can also induce renal resistance for PTH and modify 1,25-dihydroxyvitamin D ranges (4).
We have now had two circumstances in our division during which handled hypoparathyroid sufferers with steady Ca ranges developed hypercalcemia together with supplementary Mg use. Each of those sufferers had regular Ca ranges whereas utilizing the identical doses of Ca and vitamin D analog. One of many sufferers had the Mg degree checked earlier than hypercalcemia, and it was within the reference vary. In each circumstances, the Mg degree was measured after the event of hypercalcemia, and it was regular as properly. Thus, the present pilot research was designed to show whether or not Mg supplementation influences Ca metabolism in handled hypoparathyroid sufferers. To our information, there was no potential research wanting on the impact of supplementary Mg on Ca and phosphate homeostasis in hypoparathyroid sufferers.
Topics and Strategies
Research individuals have been recruited from consecutive hypoparathyroid sufferers handled in our heart of endocrinology. Inclusion standards have been: 1) hypoparathyroidism handled with Ca and vitamin D analog; 2) ionized Ca (iCa) degree of 1.0–1.29 (reference vary, 1.16–1.29) mmol/liter at research entry; 3) regular Mg degree (reference vary, 0.7–1.05 mmol/liter); 4) age not less than 18 yr; and 5) TSH degree of 0.1–10 (reference vary, 0.4–4) mU/liter.
Exclusion standards have been: 1) concomitant situation presumably affecting plasma Ca degree (malabsorption, most cancers, and so on.); 2) being pregnant; 3) creatinine degree better than 150 μmol/liter; and 4) use of Mg complement throughout final 2 months.
All topics signed an knowledgeable consent kind. The research was permitted by the Committee of Ethics for Human Research of Tartu College (protocol no. 176/T-2) and complied with the moral ideas of the Declaration of Helsinki. The research protocol was revealed at www.clinicaltrials.gov (NCT 00824226).
Research design
All individuals continued their therapy for hypoparathyroidism. An oral Mg complement (Magnex 350, containing 350 mg Mg; Vitabalans OY, Hämeenlinna, Finland) was administered for 3 wk, adopted by 2 wk off therapy.
Plasma parameters have been measured initially of the research, after 3 wk on Mg, and a couple of wk after discontinuation of the Mg complement.
Blood chemistry
iCa, phosphate, Mg, and creatinine ranges have been decided. TSH and PTH ranges have been additionally measured originally of the research. All blood chemistry measurements have been carried out by the Medical Laboratory of Tartu College Hospital.
The first endpoint was a change in iCa ranges after 3 wk of Mg therapy. A t check for dependent samples was used to find out the importance of any variations.
Outcomes
The medical traits of sufferers are proven in Desk 1.
Among the many 11 sufferers screened, one was excluded on account of concomitant gluten enteropathy. The rest (eight females and two males, all with postoperative hypoparathyroidism) have been recruited into the research, and all accomplished the research. All sufferers used calcitriol as a vitamin D analog.
The outcomes are proven in Desk 2.
There was no change in iCa, phosphate, or creatinine ranges throughout the research. Mg ranges have been barely increased after 3 wk of Mg therapy (P < 0.025).
Dialogue
The primary discovering of the present research was that 3 wk of Mg supplementation didn’t affect plasma iCa ranges in hypoparathyroid sufferers. All research sufferers (together with the affected person excluded after screening) had regular Mg ranges with out further Mg use. That is in step with a earlier research displaying that hypoparathyroid sufferers had elevated Mg ranges in blood cells however regular plasma ranges (10). In distinction, Winer et al. (1, 3) reported that of their research populations many sufferers wanted Mg supplementation to take care of regular Mg ranges. Low ranges of Mg have been famous not solely in kids with hereditary types of hypoparathyroidism but in addition in grownup postsurgical sufferers (1, 3). We speculate that not less than among the discrepancy could derive from potential variations within the dietary sample of sufferers.
Though there are numerous potential websites at which Mg could intrude with the metabolism of Ca, most research counsel that the important thing course of during which Mg is concerned is within the secretion of PTH. Different potential websites contain the renal clearance of Ca and the renal results of PTH. Thus, provided that our sufferers have been poor in PTH, it isn’t stunning that Mg therapy had no impact on plasma Ca ranges.
The small, however statistically vital increment in Mg ranges demonstrates that sufferers have been compliant with the therapy. The rationale why the 2 index sufferers developed hypercalcemia stays obscure. One in every of them participated within the present research and had no change in iCa degree after 3 wk on Mg. It appears potential that hypercalcemia was induced by inaccurate dosing of vitamin D analog by the sufferers and the usage of Mg supplementation was a mere coincidence.
The research has a number of limitations. The primary limitation is that it was designed as a pilot research, and due to this fact we didn’t use a placebo group. Nonetheless, as a result of the plasma iCa degree is a sturdy endpoint and the research included an off-treatment interval throughout which no modifications in any parameter have been detected, we imagine that the research outcomes are related. As a result of it was a pilot research, we didn’t carry out energy calculation prematurely. Nonetheless, put up hoc evaluation confirmed that the research had 80% energy to detect a change of 0.1 mmol/liter in iCa degree. One other limitation of the research is the comparatively brief interval of Mg supplementation. Once more, as a result of there was not even a pattern towards hypercalcemia, it appears cheap to imagine {that a} longer interval of therapy with Mg wouldn’t induce hypercalcemia.
We conclude that 3 wk of oral Mg therapy doesn’t affect plasma Ca ranges in handled hypoparathyroid sufferers.
Acknowledgments
This research was supported by the Estonian Ministry of Training and Analysis (SF 0180148s08).
Medical Trial Registration no. NCT 00824226 at www.clinicaltrials.gov.
Disclosure Abstract: The authors don’t have anything to reveal.
Abbreviations – “if magnesium is high is calcium high”
References