Long-Term Magnesium Supplementation in Essential Hypertension

Abstract

The main objective of this clinical trial was to evaluate the effects of magnesium pidolate (15 mmol/day) on blood pressure at rest and during sympathetic stimulation induced by cold, isometric and tilt test; peripheral blood flow has been evaluated by strain-gauge plethysmography. Fourteen mild to moderate hypertensives (8 males, 6 females, age range 40-60 years) were randomly given magnesium or placebo in a double-blind parallel clinical trial for 6 months. In the actively treated group magnesium urinary excretion increased from 5.3 ± 2 to 7.7 ± 2 mmol/24h, and serum magnesium changed from 0.9 ± 0.1 to 1.0 ± 0.2 mmol/l. On magnesium, BP changed at rest from 156/97 ± 12/4 to 149/90 ± 8/3 mm Hg, during cold pressor test from 169/105 ± 9/6 to 174/105 ± 15/4, during isometric exercise from 170/107 ± 13/9 to 170/105 ± 20/6, and during tilt test from 149/96 ± 11/6 to 153/96 ± 17/7 mm Hg. Similar changes were observed in the placebo group. Peripheral resistances were 14.7 ± 4 and 9.8 ± 2 PRU before and after magnesium, respectively. These data indicate that long-term magnesium pidolate supplementation does not affect blood pressure at rest and during sympathetic stimulation, despite a slight, nonsignificant reduction in forearm peripheral resistance.