A Study on Serum Magnesium Concentration in the Management of Congestive Heart Failure

Lim, Jong Hoon; Chun, Kook Jin; Jeong, Joon Hoon; Kim, Byung Jin; Oah, Hyun Myung; Park, Yong Hyun; Park, Yoong In; Hong, Taek Jong; Shin, Yung Woo

Abstract

OBJECTIVES
There are many interesting reports suggesting that magnesium(Mg) deficiency is deleterious in patients with congestive heart failure (CHF). It is paradoxical that the most important cause of Mg deficiency in these persons is maybe use of therapeutics including diuretics. Authors investigated the trend of serum and 24 hour urine Mg with other relating electrolytes in Mg homeostasis prospectively, in the management of CHF. And we assessd the effects of medications and many variables in .CHF on serum Mg, and the usefulness of serum Mg representing the body content.
METHODS
Fifty three patients who were diagnosed as CHF by clinical finding and echocardiogaphy were prescribed conventional doses of diuretics as furosemide 40mg and spironolactone 50mg daily, with or without angiotensin converting enzyme(ACE) inhibitor and digitalis. And then, serial serum and 24 hour urine Mg, sodium, potassium and calcium were obtained at admission, 2nd day, 5th day, and discharge.
RESULTS
The patients group with chronic CHF, which was defined as long-term use of diuretics over 6 months, showed higher prevalence of low level of serum Mg concentration than the group with acute one(11 of 28, 39% vs. 2 of 25. 8%, P< 0.01). Of those two groups, the latter showed upward trend of serum Mg from admission to discharge, but the former showed no change. In 24 hour urine Mg excretion, the amount of the patients with CHF was larger than that of control group. In the chronic CHF group, the effect of digitalis on decreasing serum Mg was evident. Serum Mg of acute CHF group correlated with serum BUN(r=0.5609). Whereas, that of chronic group with ejection fraction(r=-0.4742) and plasma renin activity(r=-0.3791), with serum potassium(r=0.4673) and creatinine(0.5846). Serum Mg may be useful indicator of Mg homeostasis, especially in chronic CHF patients.
CONCLUSION
Because patients with chronic CHF were prone to deficiency of Mg in the management, maintaining the adequate serum Mg through long- term replacement seems very important in decreasing the morbidity and mortality of these persons.