Transcript levels of AKR1B1, SORD, AGER, TGFB1, PAI1, PRKCB, EDN1, VEGFA, BGN, FN1, COL1A1, THBS1, EGR1, and NFAT5, all implicated in diabetes complications, correlated significantly with HbA1c levels of diabetic subjects (Fig. S1 in the ESM), confirming molecular effects of hyperglycemia on renal tissue even before functional impairment. This evidence concerns the gene COL1A1 and Hyperglycemia.