Relationship between the magnesium depletion score and all-cause and cardiovascular mortality among asthma patients: A Study based on the NHANES population from 2005–2018

Background

This study aimed to investigate the potential association between magnesium depletion score (MDS), a novel assessment of magnesium status in vivo, and all-cause and cardiovascular mortality in asthma patients.

Methods

Using data from the National Health and Nutrition Examination Survey (NHANES) from 2005 to 2018, 4757 asthmatics were included in the study and were categorized into four groups based on their MDS levels (MDS=0, MDS=1, MDS=2, and MDS≥3). Survival differences between the different MDS groups were analysed using Kaplan-Meier curves, and weighted multivariate Cox regression models assessed the relationship between MDS and mortality. In addition, non-linear relationships between MDS and all-cause and cardiovascular mortality were explored using restricted cubic spline (RCS) regression models, and subgroup analyses were performed to validate the results.

Results

Kaplan-Meier curves showed that both all-cause and cardiovascular mortality were significantly higher in the group with higher levels of MDS (P < 0.001). After controlling for all confounders, asthmatics in the higher MDS group faced a higher risk of death compared with the lower MDS group, as evidenced by a 3.29-fold increase in all-cause mortality (95 % CI: 2.05, 5.29) and a 4.68-fold increase in cardiovascular mortality (95 % CI: 1.77, 12.35). Fully adjusted Cox regression models further confirmed the significant positive association of high MDS with the risk of all-cause and cardiovascular mortality.RCS plots revealed a linear dose-response relationship between MDS and mortality. In the subgroup analyses, no interaction factors other than cardiovascular disease were found to significantly influence the relationship between MDS and mortality.

Conclusion

Higher levels of MDS independently predicted the risk of mortality, especially cardiovascular mortality, in US adults with asthma. Therefore, the MDS may become a cost-effective and widely applicable prognostic assessment tool for asthma, providing an important reference for clinical decision-making and patient management.