Effects of acute magnesium loading on pulmonary function of stable COPD patients.

BACKGROUND

Magnesium (Mg) use has the potential to promote bronchodilatation and to improve lung function in obstructive diseases. IV administration of Mg during exacerbations of chronic obstructive pulmonary disease (COPD) has led to improved peak flow. This study aimed to investigate the effects of acute IV Mg loading on respiratory parameters of stable COPD patients.

MATERIAL/METHODS: This was a randomized, double-blind, placebo-controlled crossover study. Twenty-two male COPD patients (64+/-6 years old, FEV1: 49+/-20%) received an IV infusion of 2 g of magnesium sulfate or placebo on two distinct occasions. Spirometry and mouth maximal respiratory pressures were obtained before and 45 minutes after the infusions.

RESULTS

Mg use led to significant changes in functional respiratory capacity (-0.48 l, 95%CI: -0.96, -0.01), inspiratory capacity (0.21 l, 95%CI: 0.04, 0.37), maximal inspiratory pressure (10 cmH2O, 95%CI: 1.6, 18.4), and maximal expiratory capacity (10.7 cmH2O, 95%CI: 0.20, 21.2). The treatment was also associated with a marginally significant decrease in residual volume (-0.47 L, 95%CI: -0.96, 0.02, p=0.06).

CONCLUSIONS

Acute IV Mg loading in stable COPD patients was associated with a reduction in lung hyperinflation and improvement of respiratory muscle strength. The clinical potential for chronic magnesium supplementation in COPD deserves further investigation.