Causal association between air pollution and frailty: a Mendelian randomization study

BACKGROUNDS: Frailty is a significant problem for older persons since it is linked to a number of unfavorable consequences. According to observational researches, air pollution may raise the risk of frailty. We investigated the causal association between frailty and air pollution (including PM(2.5), PM(2.5–10), PM(10), nitrogen dioxide, and nitrogen oxides) using Mendelian randomization approach. METHODS: We conducted MR analysis using extensive publically accessible GWAS (genome-wide association studies) summary data. The inverse variance weighted (IVW) method was employed as the primary analysis method. The weighted median model, MR-Egger, simple model, and weighted model approaches were chosen for quality control. The Cochran’s Q test was utilized to evaluate heterogeneity. Pleiotropy is found using the MR-Egger regression test. The MR-PRESSO method was used to recognize outliers. The leave-one-out strategy was used to conduct the sensitivity analysis. RESULTS: MR results suggested that PM(2.5) was statistically significantly associated with frailty [odds ratio (OR) = 1.33; 95%confidence interval (CI) = 1.12–1.58, p = 0.001] in IVW method. We observed no statistical association between PM(2.5–10)(OR = 1.00, 95% CI = 0.79–1.28, p = 0.979), PM(10)(OR = 0.91, 95% CI = 0.75–1.11, p = 0.364), nitrogen dioxide (OR = 0.98, 95% CI = 0.85–1.12, p = 0.730), nitrogen oxides (OR = 1.15, 95% CI = 0.98–1.36, p = 0.086) and frailty. There was no pleiotropy in the results. The sensitivity analysis based on the leave-one-out method showed that the individual single nucleotide polymorphisms (SNPs) did not affect the robustness of the results. CONCLUSION: The current MR investigation shows a causal association between PM(2.5) and frailty. Frailty’s detrimental progression may be slowed down with the help of air pollution prevention and control.