Glycosylated hemoglobin or hemoglobin A1c (HbA1c) is a stable measure of glucose homeostasis and insulin resistance over 120 days, with levels ≥6.5% defined as diabetes mellitus (DM), and levels ≥5.7% defined as prediabetes, indicating insulin insensitivity and increased risk for DM [24]. This evidence concerns the gene INS and diabetes mellitus.