Causal effect of elevated body mass index on hidradenitis suppurativa: a two-sample Mendelian randomization study.

A well-known relationship between elevated body mass index (BMI) and hidradenitis suppurativa (HS) has been observed, although the causality or directionality of this association remains unclarified due to the retrospective nature of studies and common diagnostic delays among HS patients. Through a Mendelian randomization (MR) analysis, the causal relationship between increased BMI and HS was demonstrated by inverse variance weighted (IVW), weighted median and weighted mode methods. According to the IVW method, the odd ratio for HS was 2.62 for each one standard deviation increase in genetically predicted BMI levels. The robustness of this analysis was further confirmed by Cochran's Q test, MR Egger Intercept test, MR PRESSO global test and "leave-one-SNP-out" analysis.