Kidney disease is the major cause of morbidity and mortality in patients with diabetes. Poor glycemic control shows the strongest correlation with diabetic kidney disease (DKD) development. A period of poor glycemia increases kidney disease risk even after an extended period of improved glucose control—a phenomenon called metabolic memory. Changes in the epigenome have been proposed to mediate the metabolic memory effect, as epigenome editing enzymes are regulated by substrates of intermediate metabolism and changes in the epigenome can be maintained after cell division.

Epigenome-wide association studies (EWAS) have reported differentially methylated cytosines in blood and kidney samples of DKD subjects when compared with controls. Differentially methylated cytosines were enriched on regulatory regions and some correlated with gene expression. Methylation changes predicted the speed of kidney function decline. Site-specific methylome editing tools now can be used to interrogate the functional role of differentially methylated regions.

Methylome changes can be detected in blood and kidneys of patients with DKD. Methylation changes can predict future kidney function changes. Future studies shall determine their role in disease development.