ORAL MAGNESIUM SUPPLEMENTATION IN INSULIN-REQUIRING TYPE-2 DIABETIC-PATIENTS

Oral magnesium (Mg) supplementation can improve insulin sensitivity an d secretion in patients with Type 2 diabetes mellitus (DM). We studied the effect of Mg supplementation on glycaemic control, blood pressure , and plasma lipids in insulin-requiring patients with Type 2 DM. Fift y moderately controlled patients were randomized to 15 mmol Mg or plac ebo daily for 3 months. Plasma Mg, glucose, HbA(1c), lipids, erythrocy te Mg, Mg and glucose concentrations in 24-h urine, and systolic and d iastolic pressure were measured before and after 3 months treatment. P lasma Mg concentration was higher after supplementation than after pla cebo (0.82 +/- 0.07 vs 0.78 +/- 0.08 mmol l(-1), p < 0.05), as was Mg excretion (5.5 +/- 1.9 vs 3.7 +/- 1.4 mmol 24 h(-1), p = 0.004) but er ythrocyte Mg concentrations were similar. No significant differences w ere found in glycaemic control (glucose: 10.7 +/- 3.8 vs 11.6 +/- 6.2 mmol l(-1), p = 0.8; HbA(1c), : 8.9 +/- 1.6 vs 9.1 +/- 1.2%, p = 0.8), lipids or blood pressure. On-treatment analysis (34 patients: 18 on M g, 16 on placebo) yielded similar results. An increase in plasma Mg co ncentration irrespective of medication was associated with a tendency to a decrease in diastolic pressure (increased plasma Mg vs no increas e: -4.0 +/- 10.1 vs +2.5 +/- 12.0 mmHg, p = 0.059). Three months' oral Mg supplementation of insulin-requiring patients with Type 2 DM incre ased plasma Mg concentration and urinary Mg excretion but had no effec t on glycaemic control or plasma lipid concentrations. (C) 1998 John W iley & Sons, Ltd.