Magnesium and C-reactive protein in heart failure: an anti-inflammatory effect of magnesium administration?

BACKGROUND Little is known about the relationship between serum magnesium (Mg) and C-reactive protein (CRP) in heart failure (HF). AIM OF THE STUDY To investigate the relationship, if any, between serum Mg and CRP in HF patients and, concomitantly, to test a hypothesis that Mg supplementation might affect serum CRP levels. METHODS Serum Mg and CRP were evaluated in 68 patients with chronic systolic HF leading to hospital admission and 65 patients requiring hospitalization for other causes. Following 5 weeks, serum Mg, CRP and intracellular Mg were reevaluated in 17 HF patients after administration of oral Mg citrate 300 mg/day (group A), and 18 untreated HF patients (group B). In order to obtain Gaussian distribution, logarithmic transformation of CRP was performed. RESULTS Inverse correlation was found between serum Mg and log CRP (r = -0.28, P = 0.002). Compared to controls, patients with HF demonstrated higher baseline CRP levels, independent of coexisting conditions, and lower serum Mg values. Following Mg treatment, log CRP decreased from 1.4 +/- 0.4 to 0.8 +/- 0.3 in group A (P < 0.001). No significant changes in log CRP were demonstrable in group B. Serum Mg (mmol/l) rose significantly in group A (0.74 +/- 0.04-0.88 +/- 0.08, P < 0.001), and to a lesser extent in group B (0.82 +/- 0.08-0.88 +/- 0.08, P = 0.04). Intracellular Mg significantly increased only in Mg-treated group A (P = 0.01). CONCLUSIONS Oral Mg supplementation to HF patients significantly attenuates blood levels of CRP, a biomarker of inflammation. Targeting the inflammatory cascade by Mg administration might prove a useful tool for improving the prognosis in HF.