Causal effects of circulating lipids and lipid-lowering drugs on the risk of atopic dermatitis: a mendelian randomization study

Lipid metabolism disorders are frequently noted in atopic dermatitis (AD) patients, prompting the long-term use of lipid-lowering drugs. However, the causal effects of circulating lipids and different lipid-lowering drugs on the risk of AD are not thoroughly understood. Using publicly available genome-wide association studies (GWAS) summary data from two different cohorts, a series of Mendelian randomization (MR) analyses were conducted to explore the causal effects of genetically proxied circulating lipids and lipid-lowering drugs on the risk of AD. Statistically, the random-effects inverse-variance-weighted (IVW) model was used as main analysis and several methods were conducted for sensitivity analysis to test the robustness of our results. Our findings revealed reduced risks of AD related to genetically proxied subtilisin/kexin type 9 (PCSK9) inhibition and lipoprotein lipase (LPL) agonist, while an increased AD risk associated with Niemann-Pick C1-like 1 (NPC1L1) inhibition. Circulating lipids and other drug targets did not show significant associations with AD risk. These results were replicated in the validation cohort; sensitivity analyses confirmed the robustness. This MR study suggests that, independent of circulating lipids, the use of PCSK9 inhibitors and LPL agonists may be associated with a decreased risk of AD, while inhibition of NPC1L1 is implicated in an increased risk. These findings may help optimize personalized selection of lipid-lowering drugs for AD patients and those at risk of AD.