Serum lipids may causally affect the occurrence of alopecia areata: A Mendelian randomization study

The etiology of alopecia areata (AA) in relation to serum lipids remains unclear, thereby prompting our intention to do Mendelian study on this subject.

Two-sample Mendelian randomization (MR) analysis was performed in the study. The inverse variance-weighted method was used as the primary method.

In our study, we integrated a set of 123 single-nucleotide polymorphisms (SNPs) into our analysis. These SNPs have been extensively studied and are known to exhibit associations with serum lipids. We sourced these SNPs from a variety of relevant studies and consortia that specifically focus on lipid-related research, such as the MRC Integrative Epidemiology Unit. These carefully curated SNPs were then utilized as instrumental variables in our analysis, allowing us to explore and evaluate the causal relationships between these genetic variants and serum lipids. By incorporating this comprehensive set of SNPs, we aimed to enhance the precision and robustness of our findings, shedding light on the intricate interplay between genetics and serum lipids.

In the MR analysis, a higher total lipid concentration in large low-density lipoprotein (LDL) particles (odds ratio [OR] = 1.502; 95% confidence interval [CI] = 1.086-1.953; p = 0.006), a greater ratio of cholesteryl esters to total lipids in chylomicrons and extremely large very LDL (VLDL) particles (OR = 2.174; 95% CI = 1.300-2.500; p = 0.010), and a greater ratio of cholesterol to total lipids in chylomicrons and extremely large VLDL particles (OR = 2.363;95% CI = 1.556-4.438; p = 0.004), were genetically predicted to be causally associated with an increased risk of AA, while patients with a higher triglyceride to total lipids ratio in chylomicrons and extremely large VLDL particles had a lower risk of AA (OR = 0.481; 95% CI = 0.191-1.270; p = 0.002).

This study found that serum lipids may be causally implicated in AA.