164 MAGNESIUM STATUS AND THERAPY IN BORDERLINE HYPERTENSION

Abstract

Background, Design and Methods: The electrolyte magnesium plays an important role in the development of primary hypertension. Therefore we have measured plasma and intracdellular Mg++ levels in erythrocytes in 18 untreated borderline hypertensive patients and in 35 untreated normotensive healthy subjects as controls. Results: In patients intracellular Mg++ content was significantly lower (1.61+/−0.09 mmmol/l, mean +/− SD), than in controls (1.84+/−0.14 mmol, p < 0.05). After 12 − 15 weeks of an oral supplementation with 240 − 480 mg Mg++/day, the erythrocyte Mg++ content had increased significantly in the borderline hypertensive group (1.78+/−0.11 mmol/l) (p < 0.05). There was no significant difference between the normotensive and borderline hypertensive group in plasma Mg++ concentrations (0.87+/−0.13 versus 0.83+/−0.17 mmol/l). Systolic and diastolic blood pressure values of the borderline hypertensive group also normalized after oral Mg++ administration (before therapy: 147.6+/−8.5 / 87.2+/−4.4 mmHg, after therapy: 137.2+/−4.6 / 83.8+/−3.4 mmHg) (p < 0.05). After 18 − 21 weeks of magnesium-therapy in the hypertensives, blood pressure was 135.8+/−4.8 / 82.9+/−3.6 mmHg (p < 0.05) and plasma magnesium was 0.91+/−0.29 mmol/l. Conclusions: The clinical study presented here shows a positive effect of oral magnesium therapy in borderline hypertensives. This effect is time-dependent. Long-lasting magnesium therapy should be preferrend since the effects of magnesium supplementation in hypertension occur mainly after long-term treatment.