Magnesium renal wasting in calcium stone formers with idiopathic hypercalciuria contrasting with lower magnesium:calcium urinary ratio.
Plasma magnesium (PMg) and urinary calcium (UCaV) and magnesium (UMgV) were measured after four days of calcium-restricted diet in 60 controls and 82 patients classified according to their calcium excretion in three groups: normo-calciuric (NCa), dietary hypercalciuria (DH) and idiopathic hypercalciuria (IH). When compared to controls, higher UMgV (4.26 +/- 0.28 mmol/d versus 3.4 +/- 0.16, p less than 0.01), lower PMg (0.79 +/- 0.01 mmol/d versus 0.84 +/- 0.01, p less than 0.05) and lower UMg/UCa ratio (0.6 +/- 0.04 versus 1.68 +/- 0.15, p less than 0.001) were observed only in IH. A significant correlation between UMgV and UCaV was found in controls, in NCa and in DH but not in IH. In conclusion, (1) the coexistence of a higher UMgV and of a lower PMg in IH suggests that there is a magnesium depletion in this group of patients; (2) since the lower UMg/UCa ratio may favour a higher propensity for calcium crystallisation and is seen only in IH, magnesium supplements may be specially indicated in this group.
D002118:Calcium / Q000652:urine*; D002136:Calcium, Dietary / Q000008:administration & dosage; D006801:Humans; D007668:Kidney / Q000378:metabolism; D008274:Magnesium / Q000378:metabolism* / Q000627:therapeutic use; D014545:Urinary Calculi / Q000378:metabolism* / Q000628:therapy
D002136:Calcium, Dietary; D008274:Magnesium; D002118:Calcium