Fig. 1

Differentially methylated positions in all analyzed contrasts. Volcano plot showing raw − log10 (p value) versus log-fold change of M values and the Manhattan plot showing the position of probes with their corresponding unadjusted p values across the genome in a M10h vs M0, b M7d vs M0, and c M7d vs M10h sample comparisons. The significant CpG sites (after FDR correction) are highlighted in red. M0—before starting a metformin therapy; M10h—10 h after the first metformin intake, before the second tablet; M7d—time point after 7 days of metformin administration