We then carried out miRNA eQTL analysis on the full set of miRNAs that were profiled, to assess whether genetic variation influences the expression level of miRNAs. We performed the eQTL analysis by modelling the effect of all cis-located SNPs on each of the target miRNAs, using a linear mixed-effects model, assuming an additive genetic effect and correcting for relevant covariates (see Materials and Methods). Abdominal and gluteal adipose tissue samples were considered separately in the miRNA eQTL analysis. We considered cis-SNPs located within an arbitrarily chosen region of 50 kilobases (kb) up-/down-stream from the miRNA sequence in the analysis. As in the analysis of tissue-specific differential miRNA expression (described above), we employed a likelihood ratio test to establish the ranking and significance of the genetic effect in each eQTL model (see Materials and Methods). These analyses revealed a modest excess of low p-values compared to the null distribution (see Figure S5). We carried forward 19 miRNA eQTLs in abdominal fat tissue (Table S4) and 11 in gluteal fat tissue (Table S5) for replication, using an arbitrary p-value threshold<0.001 (see Materials and Methods).
