MAGNESIUM STATUS AND EXCRETION IN AGE-MATCHED SUBJECTS WITH NORMAL AND ELEVATED BLOOD PRESSURES

Plasma, erythrocyte, and leucocyte magnesium (Mg) concentration, as we ll as urinary Mg, calcium (Ca), and phosphorus (P) excretion were dete rmined in male subjects with elevated diastolic blood pressure (DBP) > 90 mmHg. These parameters were compared to those in normotensive age-m atched (DBP < 85 mmHg) and drug-treated hypertensive subjects. Mg and Ca were determined by atomic absorption spectroscopy and P was determi ned by a colorimetric method. Urinary excretion was expressed in terms of creatinine (Cr) excretion. There were no significant differences i n plasma, erythrocyte, or leucocyte Mg concentrations. Both urinary Ca and Mg were significantly decreased in the group with elevated blood pressure (BP) and the drug-treated group compared to the normotensive group. Urinary P was elevated in the drug-treated hypertensive group. Of all the variables studied, urinary Mg was the only one that was sig nificantly inversely correlated with both systolic (SBP) and DBP. Thes e data suggest that decreased urinary Mg, which may be indicative of a decreased Mg intake, is associated with hypertension.