Causal effects of different types of physical activity on allergic rhinitis: A Mendelian randomization study

This study utilized Mendelian randomization (MR) with GWAS data to explore causal links between physical activity and allergic rhinitis (AR), aiming to identify lifestyle intervention targets. AR served as the outcome, with exposures including heavy/light do-it-yourself, exercises (e.g., cycling, swimming), and walking-related factors. C-reactive protein (CRP) was set as a mediator, and covariates like vitamin D and air pollution were controlled. Analyses included 2-sample MR, multivariable MR (MVMR), LD score regression (LDSC), and MR mediation. Cycling (IVW: OR = 0.01, P = .005) and faster walking pace (OR = 0.47, P = .001) were significantly associated with reduced AR risk. LDSC supported genetic correlation for walking pace (P = .004). MVMR confirmed independent effects, while MR mediation showed walking pace lowered CRP levels (OR = 0.569, P = 2.39e - 15), and elevated CRP increased AR risk (OR = 1.096, P = .030), with CRP mediating 6.9% of the protective effect. Cycling and brisk walking may reduce AR risk, with walking's benefit partially mediated by CRP. These findings highlight physical activity as a potential lifestyle intervention for AR prevention.