Metabolic and hemodynamic effects of magnesium supplementation in patients with essential hypertension

Abstract

The effect of magnesium supplementation on blood pressure, erythrocyte cation metabolism, and serum lipids was evaluated in 13 patients with mild hypertension. After randomization and a 3-wk placebo run-in period, seven patients received 40 mmol Mg aspartate (20 mmol elemental Mg twice daily) and six received placebo for 3 mo. In comparison with placebo treatment, magnesium aspartate therapy had no effect on blood pressure, lipid concentrations, or erythrocyte cation metabolism. These results demonstrate that in magnesium-repleted hypertensive subjects, magnesium supplementation does not affect blood pressure or lipids probably because magnesium has no effect on cellular cation metabolism in magnesium-replete individuals.

The effect of magnesium supplementation on biochemical markers of bone metabolism or blood pressure in healthy young adult females

“…Furthermore, supplementation of the usual diet with additional Mg ( $ 10 mmolad) for a 28 d period had no signi®cant effect on serum Mg concentration. This is in agreement with the ®ndings of other studies which show that serum Mg in healthy subjects was unaffected by Mg supplementation (Zemel et al, 1990;Geleijnse et al, 1994;Plum-Wirell et al, 1994;Witteman et al, 1994), con®rming that serum Mg concentration is tightly regulated, even when Mg intake is higher than normal.…”

“…However, intervention studies with Mg therapy in hypertensives and normotensives have led to con¯icting results. Several studies in hypertensives and normotensives have shown a blood pressure lowering effect of Mg supplements (in hypertensives, Dyckner & Wester, 1983;Saito et al, 1988;Motoyama et al, 1989;Geleijnse et al, 1994;Witteman et al, 1994;in normotensives, Itoh et al, 1997), while others have not (in hypertensives, Cohen et al, 1984;Cappuccio et al, 1985;Henderson et al, 1986;Zemel et al, 1990;Durlach et al, 1992;Haga, 1992;Kisters et al, 1993;Plum-Wirell et al, 1994;Sacks et al, 1995;in normotensives, Haga, 1992;Yamamote et al, 1995;Sacks et al, 1998). Therefore, the effect of oral Mg supplementation on blood pressure remains controversial and especially, in normotensives where data is limited.…”

Effect of magnesium supplementation on blood pressure: a meta-analysis

“…The average reduction in BP based on an effect size of 0.36 for DBP and 0.32 for SBP translate to an actual reduction of 2 --3 mm Hg for DBP and 3 --4 mm Hg for SBP. At the lower dosage 24 the effect sizes for SBP and DBP were 0.87 and 1.03, respectively, whereas at the higher dosage 25 effect sizes were seen to be À1.53 and À0.57, although Zemel et al's 25 work was anomalous to other higher-dosage studies. The overall effect size for DBP was slightly higher than that for SBP.…”

“…Those using o370 mg demonstrated high levels of variation. One anomaly for this was the study by Zemel et al, 25 which used the highest dosage of 973 mg Mg/day but showed wide CI limits (DBP 95% CI À1.69 to 0.55, SBP À2.83 to À0.23) and a low effect size of À0.57 and À1.53 for DBP and SBP, respectively. This may be attributed to the small cohort size (n ¼ 13) or to study design.…”

“…Of the 22 studies in this meta-analysis, 13 reported adverse effects from the intervention and placebo treatments, 4,15,16,18 --22,28 --32 six reported no adverse effects 24,33 --38 and three did not report any information relating to adverse effects. 17,23,25 Of these studies, the adverse effects were largely either diarrhoea, or unspecific mild abdominal or bone pain. Only three studies reported serious adverse effects from the treatments that led to withdrawal from the investigations: Lind et al 29 reported one case of visual impairment of a subject on magnesium treatment; Wirrel et al 31 reported a myocardial infarction of a subject but did not specify the treatment that the subject was receiving; Plum-Wirrell et al 32 reported a blood coagulation defect of one subject but also did not specify the treatment arm.…”