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

BackgroundsFrailty 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 PM2.5, PM2.5–10, PM10, nitrogen dioxide, and nitrogen oxides) using Mendelian randomization approach.MethodsWe 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.ResultsMR results suggested that PM2.5 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 PM2.5–10(OR = 1.00, 95% CI = 0.79–1.28, p = 0.979), PM10(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.ConclusionThe current MR investigation shows a causal association between PM2.5 and frailty. Frailty’s detrimental progression may be slowed down with the help of air pollution prevention and control.