GSTM1 and diabetes mellitus: For each one pmol/g Hb, one SD, or two-fold SD increase in log2-HbEO, the risk of prediabetes increased by 12% (1.12, 95% CI 1.04, 1.21), 16% (1.16, 95% CI 1.04, 1.30), and 33% (1.33, 95% CI 1.02, 1.69), with an increased risk of diabetes by 18% (1.18, 95% CI 1.05, 1.37), 26% (1.26, 95% CI 1.07, 1.52), and 61% (1.61, 95% CI 1.14, 1.93), respectively.