# Atopic dermatitis and chronic sinusitis: a two-sample Mendelian randomized study

## TL;DR

This study finds a genetic link from atopic dermatitis to chronic sinusitis, suggesting shared inflammatory pathways.

## Contribution

A two-sample Mendelian randomization study confirms a causal effect of atopic dermatitis on chronic sinusitis.

## Key findings

- AD increases the risk of CRS by 15.8% (p = 7.771e-07, OR = 1.158).
- No causal effect of CRS on AD was found (p = 0.979, OR = 1.001).
- Shared inflammatory pathways are supported between AD and CRS.

## Abstract

•Mendelian analysis reveals genetic association between AD and CRS.•No reverse genetic association detected from CRS toward AD.•Results support shared inflammatory pathways in AD and CRS.

Mendelian analysis reveals genetic association between AD and CRS.

No reverse genetic association detected from CRS toward AD.

Results support shared inflammatory pathways in AD and CRS.

Despite observational studies have indicated a potential association between Atopic Dermatitis (AD) and Chronic Sinusitis (CRS), it is uncertain whether there is a causal relationship between AD and CRS. To address this ambiguity, a two-sample bidirectional Mendelian randomization methodology was utilized to examine the potential causal association between AD with CRS.

The summary data for the Genome-Wide Association Study (GWAS) on AD and CRS were sourced from the FinnGen consortium. To investigate the causal link between AD and CRS, we applied several approaches, including Inverse-Variance Weighting (IVW), MR-Egger regression, weighted median, simple mode, and weighted mode methods. Furthermore, the heterogeneity, horizontal pleiotropy, and sensitivity were investigated using several methods.

Based on the random-effect IVW approach, results showed a 15.8% increased risk of CRS in those with AD compared with non-AD populations (p = 7.771e-07, OR = 1.158, 95% CI 1.092–1.227). Inversely, there was no direct evidence that CR increased the risk of AD (p = 0.979, OR = 1.001, 95% CI 0.908–1.104). The MR-Egger intercept test results indicated an absence of horizontal pleiotropy in this study (AD: p = 0.381; CRS: p = 0.144). Additionally, the leave-one-out test demonstrated the results of both forward and backward analyses were reliable and robust.

Our study confirmed the causal effect of AD on CRS, with AD increasing the risk of developing CRS. Conversely, CRS did not affect the risk of developing AD. Our study suggested that in the prevention and treatment of CRS, physicians cannot ignore the impact of AD on CRS.

Level 2.