Lung function

Low dietary magnesium was also found to be associated with wheezes and impairment of lung function in normal subjects, while magnesium supplementation can reduce asthma symptoms. In previous studies, the cause of hypomagnesemia in patients with acute asthma has been related to the use of (32-agonists either orally or IV, or by nebulization, rather than by inhalation. Treatment with (32-agonists can reduce serum magnesium levels through urinary loss or intracellular shift. Moreover, in another study, the concomitant use of diuretics and oral steroids rather than inhaled (32-agonists was also found to be responsible for the higher prevalence of hypomagnesemia in patients with chronic obstructive airway disease. In this study, patients with chronic asthma were receiving only the inhaled form of (32-agonists when their serum electrolyte levels were measured. In addition, the use of inhaled (32-agonists was not significantly different in asthmatic patients with normal and with low electrolytes. IV aminophylline therapy has been reported to cause hypomagnesemia in susceptible individuals by increasing the urinary secretion of magnesium. Interestingly, this in turn may cause increased pulmonary irritability and consequently increase the risk of acute asthma. comments 
In this study, aminophylline therapy was found to have no significant effect on electrolyte disturbance; however, it was administered orally and only in a small number of asthmatic patients (n = 7). Therefore, the underlying cause of hypomagnesemia in patients with chronic asthma remains unclear and further studies may be needed.