Fig. 2

DNA methylation in the promoter region of SLC22A1 (cg24864413). a DNA methylation of SLC22A1 in human liver was lower in type 2 diabetes subjects receiving just metformin (n = 20), compared to those who took insulin plus metformin (n = 10) or no diabetes medication (n = 3). P value from the ANCOVA is shown after adjusting for age, sex, and the presence of non-alcoholic steatohepatitis (NASH). Post-hoc analyses were used to compare groups: ***P < 0.0001. Adjusted means and standard errors are shown. b DNA methylation of SLC22A1 in hepatocytes cultured in vitro was lower after 8 h of metformin treatment (0.5 mM) compared to insulin plus metformin treatment and to control Huh-7 cells, whereas insulin treatment (100 nM) increased DNA methylation of this CpG site (n = 4). *P < 0.05, ^a P < 0.05 compared to control, all analyzed by a paired t test. Means and standard deviations are shown