Renal hypomagnesaemia in human diabetes mellitus: its relation to glucose homeostasis

Abstract

Interrelations between magnesium and glucose metabolism were studied in 215 insulin-treated diabetic out-patients aged 7–70 years. All had normal serum creatinine concentrations (below 115 μmol/l) and none had other diseases or received drugs known to interfere with mineral metabolism. A definite hypomagnesaemia (< normal mean —2 SD) and hypermagnesiuria (> normal mean + 2 SD) occurred in 38.6% and 55% of the patients. In the presence of hypermagnesiuria the serum magnesium concentration was inversely correlated to the urinary magnesium excretion rate (R=–0.23, PR=—0.32, PR=–0.22, PR= 0.27, PR= 0.58, P<0.001, respectively). These data indicate that the net tubular reabsorption of magnesium is decreased in diabetic patients in presence of hyperglycaemia, leading to hypermagnesiuria and hypomagnesaemia.