Causal relationship between asthma and chronic rhinosinusitis: A Mendelian randomization study

Area of Science:

• Genetics
• Epidemiology
• Respiratory Medicine

Background:

• Observational studies suggest an association between asthma and chronic rhinosinusitis (CRS).
• The precise causal relationship between asthma and CRS remains unclear.
• Understanding this relationship is crucial for effective disease management.

Purpose of the Study:

• To investigate the causal relationship between asthma and CRS using a bidirectional Mendelian randomization (MR) approach.
• To determine if asthma is a risk factor for CRS, or vice versa.
• To provide genetic evidence for the etiological link between these conditions.

Main Methods:

• Utilized a 2-sample Mendelian randomization (MR) method.
• Employed genome-wide association study (GWAS) data for asthma (UKB database) and CRS (FinnGen database).
• Applied inverse-variance weighting, MR-Egger, weighted median, and weighted mode methods, with heterogeneity and pleiotropy tests (Cochrane's Q, MR-Egger intercept, MR-PRESSO, leave-one-out).

Main Results:

• A significant positive causal association was found where asthma increases the risk of CRS (OR=1.320, P<0.001).
• No significant causal association was observed in the reverse direction, with CRS not increasing the risk of asthma (OR=1.030, P=0.065).
• No evidence of heterogeneity or horizontal pleiotropy was detected in either direction.

Conclusions:

• Asthma is a potential risk factor for the development of chronic rhinosinusitis (CRS).
• Chronic rhinosinusitis (CRS) does not appear to be a risk factor for developing asthma.
• Findings support a unidirectional causal link, informing future prevention and treatment strategies for both conditions.