Association between serum copper and childhood asthma: A systematic review and meta-analysis

Asthma is a chronic respiratory disease with complex pathogenesis. Some studies suggest that certain trace metals may be associated with asthma. However, the relationship between serum copper (Cu) and childhood asthma remains unclear. This meta-analysis evaluates the association between Cu and childhood asthma.

Studies of multiple databases were searched from inception to 2024. We recorded the standardized mean difference (SMD), 95% confidence intervals (CIs), and other data. The analysis was performed using Stata 18.0 software. Two independent reviewers appraised methodological quality using the Newcastle-Ottawa Scale. Sensitivity analysis was used to test robustness. To evaluate publication bias, we used Begg's funnel plots and Egger's regression test.

A total of 11 studies with a combined 1006 participants were included. There was no significant difference in the level of serum Cu between children with asthma cases and controls (SMD = -0.032, 95% CI: -0.291-0.228, P = 0.811). There was significant heterogeneity among the studies (I² = 73.5%, P < 0.0001). Subgroup analysis demonstrated that heterogeneity was not caused by the continent of origin, publication year, sample size, detection methods, and the mean age of participants. No publication bias was found.

There is no statistically significant association between serum Cu levels and childhood asthma. Further research, particularly large-scale prospective cohort studies, is needed to clarify this relationship.