Insomnia Associated With Increased Risk of Atopic Dermatitis: A Two-Sample Mendelian Randomization Study

The causal relationships between sleep traits and allergic diseases remain unclear. This study sought to explore their causal associations using Mendelian randomization (MR) analysis.

This study utilized summary-level data from genome-wide association studies (GWAS) and selected genetic variants associated with sleep traits as instrumental variables (IVs). For the primary analysis, the inverse-variance weighted (IVW) method was utilized. To further evaluate causal effects, we applied weighted median, weighted mode, and MR-Egger regression. Sensitivity analyses, such as linkage disequilibrium score (LDSC) regression, MR-Egger regression, Cochran's Q test, leave-one-out analysis, and MR-PRESSO, were carried out to confirm result robustness.

IVW analysis revealed that genetically predicted insomnia was causally associated with a higher risk of atopic dermatitis (OR = 1.79, 95% CI: 1.17-2.74, P = 0.01), and preferring an evening chronotype was causally associated with a lower risk of allergic rhinitis (IVW: OR = 0.99, 95% CI: 0.99-1.00, P = 0.02). The LDSC analysis further identified a significant genetic correlation between insomnia and atopic dermatitis (r_g = 0.107, P = 0.039), but not between chronotype and allergic rhinitis (r_g = -0.036, P = 0.339). No significant connections were identified between other sleep traits and allergic diseases. The MR-Egger intercept test did not indicate pleiotropy, except for the association with allergic asthma.

Chronotype and insomnia were causally associated with the efficacy of sleep-based interventions in allergic disease management.