Causal relationships between allergic diseases and significant declines in lung function: a multivariable Mendelian...

Area of Science:

• Pulmonology
• Immunology
• Genetics

Background:

• Global increase in asthma and allergic diseases, often co-occurring.
• Co-morbid allergic conditions significantly impact patient quality of life.
• Unclear independent causal links between allergic diseases and lung function.

Purpose of the Study:

• Investigate independent and interactive effects of allergic asthma, atopic dermatitis, allergic rhinitis, and allergic conjunctivitis on lung function decline.
• Elucidate causal relationships between allergic diseases and reduced lung function.
• Provide evidence for managing asthma patients with multiple allergic conditions.

Main Methods:

• Mendelian randomization (MR) analysis utilizing FinnGen and UK Biobank data.
• Selection of instrumental variables (IVs) based on established criteria.
• Application of univariable and multivariable MR approaches.

Main Results:

• Univariable MR indicated causal links between allergic conjunctivitis, atopic dermatitis, and allergic asthma with lung function decline.
• Multivariable MR revealed non-significant independent effects for atopic dermatitis and allergic conjunctivitis.
• Allergic asthma remained significantly associated with decreased lung function (OR [95%CI]: 1.019 [1.008-1.030], p < .001).

Conclusions:

• Atopic dermatitis and allergic conjunctivitis may indirectly affect lung function but lack independent causal impact when asthma is controlled.
• Acute exacerbations of other allergic diseases are unlikely primary drivers of lung function decline in well-managed asthma patients.
• Emphasizes the importance of effective asthma management for maintaining lung function in patients with multiple allergic conditions.