<p>Metabolic memory (persistent benefits of early glycemic control on preventing/delaying diabetic complications development) was observed in the Diabetes Control and Complications Trial (DCCT) and follow-up Epidemiology of Diabetes Interventions and Complications (EDIC) study, <a href="https://www.ncbi.nlm.nih.gov/projects/gap/cgi-bin/study.cgi?study_id=phs000086">dbGaP phs000086.v3.p1</a>, but mechanisms are unclear. We investigated the involvement of epigenetic DNA methylation (DNAme) by examining its associations with preceding glycemic history, and subsequent complications development over 18 years in blood DNAs of 499 randomly-selected DCCT/EDIC participants with type 1 diabetes. We found associations between DNAme near DCCT-closeout and mean-DCCT-HbA1c at 186 CpGs (FDR&#x3C;15%, including 43 at FDR&#x3C;5%), many located in complications-related genes. These CpGs are enriched in C/EBP motifs, enhancer/transcription regions in blood cells/progenitors, and open chromatin-states in myeloid cells. Remarkably, several CpGs in combination explain 68-97% of the mean-DCCT-HbA1c risk of complications development during EDIC. DNAme at key CpGs appears to mediate the association between hyperglycemia and complications in metabolic memory, through modifying myeloid cell enhancer activity.</p>

DCCT/EDIC Epigenetics (DNA Methylation) Study