Serum and urinary magnesium during treatment of patients with chronic congestive heart failure.

Electrolyte disturbances are common in patients with Congestive Heart Failure (CHF) especially during long-term treatments. Unlike potassium, little is known of how magnesium is affected in these patients. This study was carried out to determine the serum and urinary concentration of magnesium in patients with CHF who were treated with lisinopril [Angiotensin-Converting Enzyme Inhibitor (ACEI)], frusemide (diuretic) and digoxin, at baseline, 2 weeks and 4 weeks. 45 patients (Group I; 24 male, 21 female; average age 49.7 years) with CHF, New York Heart Association (NYHA) Class II, III were matched with 45 healthy controls (Group II; 24 male, 21 female, average age 49.3 years). Serum and urinary magnesium were assayed by atomic absorption spectrophotometer. Statistical analysis was made by Student's t-test. At baseline, serum magnesium concentration in CHF patients was not significantly lower than in controls, p > 0.1. However, a higher loss of magnesium in urine was found in CHF patients compared with control subjects at baseline, p < 0.01. Serum magnesium concentration decreased significantly during treatment except in CHF patients on lisinopril, p < 0.05. The lowest excretion of magnesium was also found in this group of patients. Our study shows that lisinopril is magnesium-sparing in patients with CHF.