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

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

Methods: 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.

Results: 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 (rg = 0.107, P = 0.039), but not between chronotype and allergic rhinitis (rg = -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.

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