title: Effects of acute magnesium loading on pulmonary function of stable COPD patients.
abstract: 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.
  
  
  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.
authors.affiliation: Department of Internal Medicine, Medical School of Ribeirao Preto, University of Sao Paulo, Sao Paulo, Brazil.
authors.forename: Angélica Florípedes
authors.initials: AF
authors.lastname: do Amaral
authors.forename: Antonio Luiz
authors.initials: AL
authors.lastname: Rodrigues-Júnior
authors.forename: João
authors.initials: J
authors.lastname: Terra Filho
authors.forename: Hélio
authors.initials: H
authors.lastname: Vannucchi
authors.forename: José Antônio Baddini
authors.initials: JA
authors.lastname: Martinez
mesh_terms: D000368:Aged; D004311:Double-Blind Method; D005541:Forced Expiratory Volume / Q000187:drug effects; D006801:Humans; D008168:Lung / Q000187:drug effects / Q000503:physiopathology; D008274:Magnesium / Q000097:blood / Q000494:pharmacology / Q000627:therapeutic use*; D008297:Male; D008875:Middle Aged; D010919:Placebos; D029424:Pulmonary Disease, Chronic Obstructive / Q000188:drug therapy / Q000503:physiopathology; D012129:Respiratory Function Tests; D015656:Respiratory Mechanics / Q000187:drug effects; D012132:Respiratory Muscles / Q000187:drug effects; D014109:Total Lung Capacity / Q000187:drug effects
chemical_list: D010919:Placebos; D008274:Magnesium