SLC30A8 and type 2 diabetes mellitus: Combining all six CpG sites together, total mean values of SLC30A8 DNA methylation levels were significantly increased in T2D patients compared with NGT subjects (82.9%, 95% CI = 79.2% to 80.5% vs. 80.1%, 95% CI = 75.4% to 78.6%, P = 0.014) (Figure 3B).