Causal relationship between systolic blood pressure and susceptibility to allergic rhinitis in East Asian populations: A bidirectional two-sample Mendelian randomization study

Allergic rhinitis is the most common chronic disease and is also one of the most common diseases affecting adults. This study aims to explore the causal relationship between systolic blood pressure (SBP) and the risk of allergic rhinitis (AR) among East Asian populations at the genetic level. We obtained genome-wide association study data on SBP and AR in East Asian populations from the Mendelian randomization (MR) database platform. Single nucleotide polymorphisms associated with SBP were used as instrumental variables for a 2-sample Mendelian randomization analysis to investigate the causal relationship between SBP and AR. The analytical methods used included inverse variance weighting, weighted median estimation, and MR-Egger regression. The MR analysis was performed following the STROBE-MR reporting guidelines. We rigorously selected 38 single nucleotide polymorphisms significantly associated with SBP (P < 5 × 10-8; linkage disequilibrium r² < 0.001). Across all analytical methods, a consistent inverse relationship was observed between SBP and the risk of AR (inverse variance weighting: odds ratio [OR] = 0.737, 95% confidence interval [CI]: 0.565-0.960; weighted median: OR = 0.773, 95% CI: 0.539-1.109; MR-Egger: OR = 1.045, 95% CI: 0.369-2.954), indicating that lower SBP is associated with a higher risk of AR among East Asians. However, there was no evidence to support a causal effect of AR on SBP, further confirming the causal association observed in the forward MR analysis. This study provides strong evidence suggesting that lower SBP may be causally associated with an increased risk of AR in East Asian populations.