Serum magnesium levels and its correlation with level of control in patients with asthma: A hospital-based, cross-sectional, prospective study.

Context: Magnesium (Mg) is an intracellular cation which takes part in various functions including smooth muscle contractility. Studies have shown that serum Mg level has no significant effect on asthma severity. There are only sparse data on the effect of serum Mg level on asthma control.

Aims: The aim of this study was to evaluate the effect of serum Mg level on asthma control.

Settings And Design: This hospital-based cross-sectional study was conducted at the Department of Respiratory Medicine, Kasturba Medical College, Manipal.

Subjects And Methods: Our participants were adult asthma patients over 18 years of age. Asthma control was assessed using a questionnaire. Serum Mg level was estimated. The study was approved by the Institutional Ethics Committee, and informed consent was obtained from the participants.

Statistical Analysis Used: Welch's ANOVA test was used to analyze the correlation between serum Mg level and level of control of asthma.

Results: We screened 256 patients who met the inclusion criteria. After 96 patients were removed based on exclusion criteria, 160 patients were grouped into three based on the level of symptom control. Forty-eight patients belonged to the "well controlled" group, 59 in "partly controlled" group, and the remaining 53 in "uncontrolled" group. The mean serum Mg level (mg/dl) was 2.08 ± 0.37, 2.07 ± 0.28, and 1.83 ± 0.34 in well, partly, and uncontrolled groups, respectively. As the level of control of asthma decreased from well controlled to uncontrolled, the level of mean serum Mg also decreased.

Conclusions: Serum Mg levels have a positive correlation with the level of symptom control in asthma. In uncontrolled asthma, serum Mg is significantly low. Hence, it might be useful as a biomarker in assessing control or severity of asthma.