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.