Journal article
Hypocalciuria in Patients with Gitelman's Syndrome: Role of Hypomagnesemia
Acta Nephrologica, Vol.25(2), pp.70-76
06/01/2011
Abstract
BACKGROUND: Hypocalciuria and hypomagnesemia are two characteristic findings in patients with Gitelman’s syndrome (GS). Several hypomagnesemic states with intact renal medulla in humans also have hypocalciuria, suggesting the association of hypomagnesemia with hypocalciuria. We evaluate the role of hypomagnesemia on hypocalciuria in human GS. METHODS: Twelve GS patients with thiazide-sensitive sodium-chloride cotransporter (NCC) mutations received acute magnesium sulfate (MgSO4 0.35 mmol/kg) for one hour and chronic oral magnesium oxide (MgO 37 mmol daily) for four weeks. Urine and blood were obtained for determination of electrolytes, biochemistries and hormones. Twelve age- and sex-matched healthy normotensive volunteers were enrolled as controls. RESULTS: Compared with healthy subjects, GS patients had severe hypocalciuria (FE(subscript Ca) 0.15 ±0.03 vs. 1.49 ±0.23%, P ＜ 0.05; daily urinary Ca(superscript 2+) excretion 4.2 ±1.6 vs. 50.4 ±10.8 mmol, P ＜ 0.05), hypomagnesemia (0.52 ±0.1 vs. 0.85 ±0.1 mmol/L, P ＜ 0.05) and low intact parathyroid hormone (iPTH) (4.6 ±2.1 vs. 34.1 ±8.6 ng/L, P ＜ 0.05). Acute MgSO4 infusion remarkably increased urinary Ca(superscript 2+) excretion (FE(subscript Ca)/FE(subscript Na), 0.19 ±0.11 to 3.42 ±2.37, P ＜ 0.05) and serum iPTH levels (4.6 ±2.1 to 16.3 ±5.3 ng/L, P ＜ 0.05). Chronic MgO supplementation significantly raised serum Mg(superscript 2+) and i-PTH level but not urinary Ca(superscript 2+) excretion. Furthermore, four patients whose serum Mg(superscript 2+) level became normal after chronic Mg(superscript 2+) repletion had persistent hypocalciuria. CONCLUSION: Hypomagnesemia alone cannot explain completely the pathogenesis of hypocalciuria in patients with GS. Other mechanisms are worth further exploration for understanding the renal Ca(superscript 2+) and Mg(superscript 2+) handling in GS patients.
Details
- Title: Subtitle
- Hypocalciuria in Patients with Gitelman's Syndrome: Role of Hypomagnesemia
- Creators
- Chun-Chi ChenHsin-Chi WuYu-Juei HsuChih-Jen ChengSung-Sen YangPauling ChuShih-Hua Lin
- Resource Type
- Journal article
- Publication Details
- Acta Nephrologica, Vol.25(2), pp.70-76
- Publisher
- 社團法人台灣腎臟醫學會 ＆ Ainosco Press
- ISSN
- 1013-1671
- Number of pages
- 7
- Language
- English
- Date published
- 06/01/2011
- Academic Unit
- Internal Medicine; Nephrology
- Record Identifier
- 9984383270402771
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