Dietary magnesium, lung function, wheezing, and airway hyperreactivity in a random adult population sample.
ABSTRACT Magnesium is involved in a wide range of biological activities, including some that may protect against the development of asthma and chronic airflow obstruction. We tested the hypothesis that high dietary magnesium intake is associated with better lung function, and a reduced risk of airway hyper-reactivity and wheezing in a random sample of adults. In 2633 adults aged 18-70 sampled from the electoral register of an administrative area of Nottingham, UK, we measured dietary magnesium intake by semiquantitative food-frequency questionnaire, lung function as the 1-sec forced expiratory volume (FEV1), and atopy as the mean skin-prick test response to three common environmental allergens. We measured airway reactivity to methacholine in 2415 individuals, defining hyper-reactivity as a 20% fall in FEV1 after a cumulative dose of 12.25 mumol or less. Mean (SD) daily intake of magnesium was 380 (114) mg/day. After adjusting for age, sex, and height, and for the effects of atopy and smoking, a 100 mg/day higher magnesium intake was associated with a 27.7 (95% CI, 11.9-43.5) mL higher FEV1, and a reduction in the relative odds of hyper-reactivity by a ratio of 0.82 (0.72-0.93). The same incremental difference in magnesium intake was also associated with a reduction in the odds of self-reported wheeze within the past 12 months, adjusted for age, sex, smoking, atopy, and kilojoule intake, by a ratio of 0.85 (0.76-0.95). Dietary magnesium intake is independently related to lung function and the occurrence of airway hyper-reactivity and self-reported wheezing in the general population. Low magnesium intake may therefore be involved in the aetiology of asthma and chronic obstructive airways disease.
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ABSTRACT: Magnesium sulfate (MgSO(4)) has been considered as an adjunct therapy for severe and life-threatening asthma exacerbation. The literature search was performed using MEDLINE, EMBASE, Cochrane Library and Google Scholar to summarize the current state of knowledge regarding magnesium therapy in acute exacerbation of adult asthma. A total of 16 trials and 4 meta-analyses were identified. As results, intravenous MgSO(4) was beneficial in severe exacerbation, but evidence for nebulized magnesium was insufficient. However, larger trials are required to draw confirmative conclusions on the efficacy. Regarding the safety concern, the risk of major toxicity appears to be very low at usual doses described in the literature. Additionally, results from 4 surveys were examined on the gaps between knowledge and practice, and on the barrier to the use of MgSO(4) at emergency departments. This literature review summarized the up-to-date evidence on the issues regarding the use of MgSO(4) for acute asthma. We expect more studies to be conducted for evidence making in the Asian-Pacific regions.Asia Pacific allergy. 01/2012; 2(1):76-85.
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ABSTRACT: The potential influence of magnesium on exercise performance is a subject of increasing interest. Magnesium has been shown to have bronchodilatatory properties in asthma and chronic obstructive pulmonary disease patients. The aim of this study was to investigate the effects of acute magnesium IV loading on the aerobic exercise performance of stable chronic obstructive pulmonary disease patients. Twenty male chronic obstructive pulmonary disease patients (66.2 + 8.3 years old, FEV1: 49.3+19.8%) received an IV infusion of 2 g of either magnesium sulfate or saline on two randomly assigned occasions approximately two days apart. Spirometry was performed both before and 45 minutes after the infusions. A symptom-limited incremental maximal cardiopulmonary test was performed on a cycle ergometer at approximately 100 minutes after the end of the infusion. Magnesium infusion was associated with significant reductions in the functional residual capacity (-0.41 l) and residual volume (-0.47 l), the mean arterial blood pressure (-5.6 mmHg) and the cardiac double product (734.8 mmHg.bpm) at rest. Magnesium treatment led to significant increases in the maximal load reached (+8 w) and the respiratory exchange ratio (0.06) at peak exercise. The subgroup of patients who showed increases in the work load equal to or greater than 5 w also exhibited significantly greater improvements in inspiratory capacity (0.29 l). The acute IV loading of magnesium promotes a reduction in static lung hyperinflation and improves the exercise performance in stable chronic obstructive pulmonary disease patients. Improvements in respiratory mechanics appear to be responsible for the latter finding.Clinics (São Paulo, Brazil) 01/2012; 67(6):615-22. · 1.59 Impact Factor
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ABSTRACT: Magnesium (Mg) is thought to be an important element in the pathogenesis of acute asthma attacks. We hypothesized that erythrocytic Mg would be decreased during an acute asthma exacerbation. We aimed at investigating plasma and erythrocytic Mg in acute asthmatic children. This case-control study included 30 Egyptian outpatients with acute asthma. Thirty healthy matched children were included as controls. All candidates had measurements of plasma and erythrocytic Mg levels before and after treatment. No significant differences were detected in plasma Mg levels between cases and controls (1.53±0.33 mmol/L versus 1.67±0.50 mmol/L respectively, P =0.2). However, erythrocytic Mg levels were significantly reduced in cases when compared to controls (1.06±0.43 mmol/L versus 2.57±0.59 mmol/L respectively, P<0.001). Plasma Mg levels did not significantly change in acute asthmatics before and after their rescue treatment (1.53±0.33 mmol/L versus 1.68±0.31mmol/L respectively, P=0.07). In contrast, the study detected a significant increase in erythrocytic Mg levels in cases after their treatment from acute attacks (1.06±0.43 mmol/L versus 1.56±0.23 mmol/L respectively, P<0.001), with significant negative correlation with severity of attack (Spearman's rho = -0.647, P<0.001). Erythrocytic Mg levels were significantly lower during the acute asthma, and were negatively correlated with severity of exacerbation, while plasma Mg did not significantly change. Only erythrocytic Mg levels were significantly elevated after receiving rescue treatment.Iranian Journal of Pediatrics 12/2012; 22(4):463-7. · 0.26 Impact Factor