Enhanced resolution profiling in twins reveals differential methylation signatures of type 2 diabetes with links to its complications.

BACKGROUND: Type 2 diabetes (T2D) susceptibility is influenced by genetic and environmental factors. Previous findings suggest DNA methylation as a potential mechanism in T2D pathogenesis and progression. METHODS: We profiled DNA methylation in 248 blood samples from participants of European ancestry from 7 twin cohorts using a methylation sequencing platform targeting regulatory genomic regions encompassing 2,048,698 CpG sites. FINDINGS: We find and replicate 3 previously unreported T2D differentially methylated CpG positions (T2D-DMPs) at FDR 5% in RGL3, NGB and OTX2, and 20 signals at FDR 25%, of which 14 replicated. Integrating genetic variation and T2D-discordant monozygotic twin analyses, we identify both genetic-based and genetic-independent T2D-DMPs. The signals annotate to genes with established GWAS and EWAS links to T2D and its complications, including blood pressure (RGL3) and eye disease (OTX2). INTERPRETATION: The results help to improve our understanding of T2D disease pathogenesis and progression and may provide biomarkers for its complications. FUNDING: Funding acknowledgements for each cohort can be found in the Supplementary Note.

Endothelial CXCR2 deficiency attenuates renal inflammation and glycocalyx shedding through NF-κB signaling in diabetic kidney disease.

BACKGROUND: The incidence of diabetic kidney disease (DKD) continues to rapidly increase, with limited available treatment options. One of the hallmarks of DKD is persistent inflammation, but the underlying molecular mechanisms of early diabetic kidney injury remain poorly understood. C-X-C chemokine receptor 2 (CXCR2), plays an important role in the progression of inflammation-related vascular diseases and may bridge between glomerular endothelium and persistent inflammation in DKD. METHODS: Multiple methods were employed to assess the expression levels of CXCR2 and its ligands, as well as renal inflammatory response and endothelial glycocalyx shedding in patients with DKD. The effects of CXCR2 on glycocalyx shedding, and persistent renal inflammation was examined in a type 2 diabetic mouse model with Cxcr2 knockout specifically in endothelial cells (DKD-Cxcr2 eCKO mice), as well as in glomerular endothelial cells (GECs), cultured in high glucose conditions. RESULTS: CXCR2 was associated with early renal decline in DKD patients, and endothelial-specific knockout of CXCR2 significantly improved renal function in DKD mice, reduced inflammatory cell infiltration, and simultaneously decreased the expression of proinflammatory factors and chemokines in renal tissue. In DKD conditions, glycocalyx shedding was suppressed in endothelial Cxcr2 knockout mice compared to Cxcr2 L/L mice. Modulating CXCR2 expression also affected high glucose-induced inflammation and glycocalyx shedding in GECs. Mechanistically, CXCR2 deficiency inhibited the activation of NF-κB signaling, thereby regulating inflammation, restoring the endothelial glycocalyx, and alleviating DKD. CONCLUSIONS: Taken together, under DKD conditions, activation of CXCR2 exacerbates inflammation through regulation of the NF-κB pathway, leading to endothelial glycocalyx shedding and deteriorating renal function. Endothelial CXCR2 deficiency has a protective role in inflammation and glycocalyx dysfunction, suggesting its potential as a promising therapeutic target for DKD treatment.

The significance of glutaredoxins for diabetes mellitus and its complications.

Diabetes mellitus is a non-communicable metabolic disease hallmarked by chronic hyperglycemia caused by beta-cell failure. Diabetic complications affect the vasculature and result in macro- and microangiopathies, which account for a significantly increased morbidity and mortality. The rising incidence and prevalence of diabetes is a major global health burden. There are no feasible strategies for beta-cell preservation available in daily clinical practice. Therefore, patients rely on antidiabetic drugs or the application of exogenous insulin. Glutaredoxins (Grxs) are ubiquitously expressed and highly conserved members of the thioredoxin family of proteins. They have specific functions in redox-mediated signal transduction, iron homeostasis and biosynthesis of iron-sulfur (FeS) proteins, and the regulation of cell proliferation, survival, and function. The involvement of Grxs in chronic diseases has been a topic of research for several decades, suggesting them as therapeutic targets. Little is known about their role in diabetes and its complications. Therefore, this review summarizes the available literature on the significance of Grxs in diabetes and its complications. In conclusion, Grxs are differentially expressed in the endocrine pancreas and in tissues affected by diabetic complications, such as the heart, the kidneys, the eye, and the vasculature. They are involved in several pathways essential for insulin signaling, metabolic inflammation, glucose and fatty acid uptake and processing, cell survival, and iron and mitochondrial metabolism. Most studies describe significant changes in glutaredoxin expression and/or activity in response to the diabetic metabolism. In general, mitigated levels of Grxs are associated with oxidative distress, cell damage, and even cell death. The induced overexpression is considered a potential part of the cellular stress-response, counteracting oxidative distress and exerting beneficial impact on cell function such as insulin secretion, cytokine expression, and enzyme activity.

LncRNA as a regulator in the development of diabetic complications.

Diabetes is a metabolic disease characterized by hyperglycemia, which induces the production of AGEs, ROS, inflammatory cytokines, and growth factors, leading to the formation of vascular dysfunction and target organ damage, promoting the development of diabetic complications. Diabetic nephropathy, retinopathy, and cardiomyopathy are common complications of diabetes, which are major contributors to disability and death in people with diabetes. Long non-coding RNAs affect gene transcription, mRNA stability, and translation efficiency to influence gene expression for a variety of biological functions. Over the past decade, it has been demonstrated that dysregulated long non-coding RNAs are extensively engaged in the pathogenesis of many diseases, including diabetic complications. Thus, this review discusses the regulations of long non-coding RNAs on the primary pathogenesis of diabetic complications (oxidative stress, inflammation, fibrosis, and microvascular dysfunction), and some of these long non-coding RNAs may function as potential biomarkers or therapeutic targets for diabetic complications.

Genetics and epigenetics of diabetes and its complications in India.

Diabetes mellitus (DM) has become a significant health concern with an increasing rate of morbidity and mortality worldwide. India ranks second in the number of diabetes cases in the world. The increasing burden of DM can be explained by genetic predisposition of Indians to type 2 diabetes mellitus (T2DM) coupled with rapid urbanization and socio-economic development in the last 3 decades leading to drastic changes in lifestyle. Environment and lifestyle changes contribute to T2DM development by altering epigenetic processes such as DNA methylation, histone post-translational modifications, and long non-coding RNAs, all of which regulate chromatin structure and gene expression. Although the genetic predisposition of Indians to T2DM is well established, how environmental and genetic factors interact and lead to T2DM is not well understood. In this review, we discuss the prevalence of diabetes and its complications across different states in India and how various risk factors contribute to its pathogenesis. The review also highlights the role of genetic predisposition among the Indian population and epigenetic factors involved in the etiology of diabetes. Lastly, we review current treatments and emphasize the knowledge gap with respect to genetic and epigenetic factors in the Indian context. Further understanding of the genetic and epigenetic determinants will help in risk prediction and prevention as well as therapeutic interventions, which will improve the clinical management of diabetes and associated macro- and micro-vascular complications.

The bone mesenchymal stem cell-derived exosomal miR-146a-5p promotes diabetic wound healing in mice via macrophage M1/M2 polarization.

A diabetic wound is a refractory disease that afflicts patients globally. MicroRNA-146a-5p (miR-146a-5p) is reported to represent a potential therapeutic target for diabetic wounds. However, microRNA easily degrades in the wound microenvironment. This study extracted bone marrow mesenchymal stem cell (BMSC)-derived exosomes (EXO). Electroporation technology was used to load miR-146a-5p into EXO (labeled as EXO-miR-146a). The endothelial cells (human umbilical vein endothelial cells [HUVECs]) and macrophages were cocultured in transwell chambers in the presence of high glucose. Cell proliferation, migration, and angiogenesis were measured with cell counting kit 8, scratch, and tube forming assays, respectively. Flow cytometry was introduced to validate the biomarker of macrophages and BMSCs. The expression level of macrophage polarization-related proteins and tumor necrosis factor receptor-associated factor 6 (TRAF6) was assessed with western blotting analysis. The full-thickness skin wound model was developed to verify the in vitro results. EXO-miR-146a promoted the proliferation, migration, and angiogenesis of HUVECs in the hyperglycemic state by suppressing the TRAF6 expression in vitro. Additionally, EXO-miR-146a treatment facilitated M2 but inhibited M1 macrophage polarization. Furthermore, EXO-miR-146a enhances reepithelialization, angiogenesis, and M2 macrophage polarization, thereby accelerating diabetic wound healing in vivo. The EXO-miR-146a facilitated M2 macrophage polarization, proliferation, migration, and angiogenesis of HUVECs through TRAF6, thereby ameliorating intractable diabetic wound healing. These results established the basis for using EXO to deliver drugs and revealed mediators for diabetic wound treatment.

Applicability of mesenchymal stem cell-derived exosomes as a cell-free miRNA therapy and epigenetic modifiers for diabetes.

Given that exosome nanovesicles constitute various growth factors, miRNAs and lncRNAs, they have implications for epigenetic modifications. Few studies have shown that exosomes from mesenchymal stem cells (MSCs) exhibit therapeutic effects on diabetic complications by substituting miRNAs and regulating histone modifications. Therefore, reversing epigenetic aberrations in diabetes may provide new insight into its treatment. This review discusses the impact of DNA and histone methylations on the development of diabetes and its complications. Further, we talk about miRNAs dysregulated in diabetic conditions and the possibility of utilizing mesenchymal stem cell (MSC) exosomes for the development of miRNA cell-free therapy and epigenetic modifiers in reversing diabetic-induced epigenetic alterations.

Long non-coding RNAs: The hidden players in diabetes mellitus-related complications.

BACKGROUND AND AIM: Long non-coding RNAs (lncRNAs) have been recognized as important regulators of gene expression in various human diseases. Diabetes mellitus (DM) is a long-term metabolic disorder associated with serious macro and microvascular complications. This review discusses the potential lncRNAs involved in DM-related complications such as dysfunction of pancreatic beta islets, nephropathy, retinopathy, cardiomyopathy, and peripheral neuropathy. METHODS: An extensive literature search was conducted in the Scopus database to find information from reputed biomedical articles published on lncRNAs and diabetic complications from 2014 to 2023. All review articles were collected and statistically analyzed, and the findings were summarized. In addition, the potential lncRNAs involved in DM-related complications, molecular mechanisms, and gene targets were discussed in detail. RESULTS: The lncRNAs ANRIL, E33, MALAT1, PVT1, Erbb4-IR, Gm4419, Gm5524, MIAT, MEG3, KNCQ1OT1, Uc.48+, BC168687, HOTAIR, and NONRATT021972 were upregulated in several diabetic complications. However, ßlinc1, H19, PLUTO, MEG3, GAS5, uc.322, HOTAIR, MIAT, TUG1, CASC2, CYP4B1-PS1-001, SOX2OT, and Crnde were downregulated. Remarkably, lncRNAs MALAT1, ANRIL, MIAT, MEG3, H19, and HOTAIR were overlapping in more than one diabetic complication and were considered potential lncRNAs. CONCLUSION: Several lncRNAs are identified as regulators of DM-related complications. The expression of lncRNAs is up or downregulated depending on the disease context, target genes, and regulatory partners. However, most lncRNAs target oxidative stress, inflammation, apoptosis, fibrosis, and angiogenesis pathways to mediate their protective/pathogenic mechanism of action and contribute to DM-related complications.

Epigenetic changes underlie the association between diabetes mellitus and oral diseases.

Patients with diabetes mellitus (DM) suffer from oral complications related to oral infections, periodontal diseases, and endodontic lesions. Emerging evidence has revealed the contribution of the epigenetic process as the underlying mechanism of DM complications. DNA methylation, histone modifications, and non-coding RNAs are epigenetic regulators that directly affect gene expression. The present review elaborated on the role of epigenetic dysregulation in the etiology of diabetes-related periodontal and endodontic diseases. The narrative review study was prepared using databases such as PubMed, Google Scholar, Science Direct, and Scopus. The formation of glycation products as a result of hyperglycemic condition increases oxidative stress, and elevates chronic inflammatory mediators that could in turn adversely change the cellular environment and alter the epigenetic status. This process contributes to the alteration of regulatory genes expression, leading to the development of diabetes-induced bone complications and impaired odontogenic capacity of pulp. Indeed, epigenetic mechanisms mediate the interaction between gene expression and DM cellular environment. Further investigations on epigenetic factors involved in DM oral complications may provide novel therapeutic targets.

Genetic and epigenetic background of diabetic kidney disease.

Diabetic kidney disease (DKD) is a severe diabetic complication that affects up to half of the individuals with diabetes. Elevated blood glucose levels are a key underlying cause of DKD, but DKD is a complex multifactorial disease, which takes years to develop. Family studies have shown that inherited factors also contribute to the risk of the disease. During the last decade, genome-wide association studies (GWASs) have emerged as a powerful tool to identify genetic risk factors for DKD. In recent years, the GWASs have acquired larger number of participants, leading to increased statistical power to detect more genetic risk factors. In addition, whole-exome and whole-genome sequencing studies are emerging, aiming to identify rare genetic risk factors for DKD, as well as epigenome-wide association studies, investigating DNA methylation in relation to DKD. This article aims to review the identified genetic and epigenetic risk factors for DKD.

MIRNA146a And Diabetes-Related Complications: A Review.

Diabetes mellitus, defined as long-standing hyperglycemic conditions caused by a defect in insulin production and activity, has become a major healthcare burden as the number of catastrophic and life-threatening complications rises. Microvascular complications (neuropathy, retinopathy, and nephropathy), and also diabetes-related macrovascular complications are common problems that arise as the life expectancy of diabetic patients has increased despite improved treatment options. While it is impossible to pinpoint the specific crucial timing when the complications become fully entrenched, looking for novel sensitive biomarkers to identify physiological changes in the initial stages would be needed. An increasing amount of data shows that miRNAs, particularly miRNA146a, are stable in a range of body fluids and can be used to identify pathogenic changes at the cellular or tissue level. In this brief review, we highlight the important functioning of miRNA146a and its putative target of action in diabetic microvascular and cardiovascular complications. A decrease in miRNA146a levels may play a critical role in the onset and development of diabetes complications, whereas its anti-inflammatory properties were revealed to be associated with the pathogenesis of numerous diabetic complications, including diabetic nephropathy, retinopathy, neuropathy, and diabetes-related cardiovascular disorders, even tending to be a potential biomarker of the disease's inflammatory status.

Role of Long Non-Coding RNA in Regulating ER Stress Response to the Progression of Diabetic Complications.

Chronic hyperglycemia damages the nerves and blood vessels, culminating in other vascular complications. Such complications enhance cytokine, oxidative and endoplasmic reticulum (ER) stress. ER is the primary organelle where proteins are synthesised and attains confirmatory changes before its site of destination. Perturbation of ER homeostasis activates signaling sensors within its lumen, the unfolded protein response (UPR) that orchestrates ER stress and is extensively studied. Increased ER stress markers are reported in diabetic complications in addition to lncRNA that acts as an upstream marker inducing ER stress response. This review focuses on the mechanisms of lncRNA that regulate ER stress markers, especially during the progression of diabetic complications. Through this systemic review, we showcase the dysfunctional lncRNAs that act as a leading cause of ER stress response to the progression of diabetic complications.

Monogenic diabetes clinic (MDC): 3-year experience.

AIM: In the pediatric diabetes clinic, patients with type 1 diabetes mellitus (T1D) account for more than 90% of cases, while monogenic forms represent about 6%. Many monogenic diabetes subtypes may respond to therapies other than insulin and have chronic diabetes complication prognosis that is different from T1D. With the aim of providing a better diagnostic pipeline and a tailored care for patients with monogenic diabetes, we set up a monogenic diabetes clinic (MDC). METHODS: In the first 3 years of activity 97 patients with non-autoimmune forms of hyperglycemia were referred to MDC. Genetic testing was requested for 80 patients and 68 genetic reports were available for review. RESULTS: In 58 subjects hyperglycemia was discovered beyond 1 year of age (Group 1) and in 10 before 1 year of age (Group 2). Genetic variants considered causative of hyperglycemia were identified in 25 and 6 patients of Group 1 and 2, respectively, with a pick up rate of 43.1% (25/58) for Group 1 and 60% (6/10) for Group 2 (global pick-up rate: 45.5%; 31/68). When we considered probands of Group 1 with a parental history of hyperglycemia, 58.3% (21/36) had a positive genetic test for GCK or HNF1A genes, while pick-up rate was 18.1% (4/22) in patients with mute family history for diabetes. Specific treatments for each condition were administered in most cases. CONCLUSION: We conclude that MDC may contribute to provide a better diabetes care in the pediatric setting.

Distinct MicroRNAs Identified in Rabbit Blood Arising from Induced Diabetes and a Surgically Simulated Diabetic Ischemia Complication.

BACKGROUND: Diabetic complications have been studied extensively in recent years. There are very few biomarkers in body fluids that can pinpoint a distinct diabetic complication due to insufficient known specific biomarkers for ischemia. OBJECTIVE: Identifying microRNA in animal models for each complication could enable early diagnosis of a given complication if verified in humans. MicroRNA (miRNA) profiling has been done in rodent models for a number of diabetic complications, like diabetic glomerular injury, atherosclerosis, cognitive impairment, diabetic wound healing, angiopathy and other complications. Due to multiple differences between rodents and humans, the changes in rabbit skin, considered closer to humans than even pigs, may better simulate human diabetic complications of ischemia. METHODS: To study the miRNA profile of rabbits in which diabetes was induced or ischemia was surgically generated, we studied whether diabetes or ischemia-induced specific miRNA could be detected. MicroRNA from the blood of diabetic rabbits and rabbits with local ischemia was collected in PAXgene Blood RNA tubes specifically designed for miRNA isolation and extracted using the PAX gene miRNA extraction kit. The isolated RNA was quality controlled using an RNA analyzer, and further, using RNA seq technology, it was analyzed for distinct miRNAs that were detected in diabetic and non-diabetic rabbits induced with ischemia. RESULTS: A miRNA that was found to be expressed in diabetic rabbits and ischemic rabbits but not in untreated rabbits was miRNA-183. Several miRNAs were differentially expressed across comparison groups, and several upregulated miRNAs were identified being unique to each comparison. In rabbits with a potential diabetic complication of a long-term ischemic model, there was one distinct microRNA, which was highly significantly upregulated in ischemia rabbit (miRNA-133-3p). One miRNA that was highly significantly upregulated in diabetic rabbit but not in ischemic rabbits was miRNA-3074-5p. Only statistically significant results have been considered and analyzed. CONCLUSION: These findings could lead to a precise and timely diagnosis of a potential single diabetic complication without invasive tissue biopsies and could be a novel tool in the management of diabetic patients developing complications due to the progression of diabetes.

Association of MMP-2 and MMP-9 Polymorphisms with Diabetes and Pathogenesis of Diabetic Complications.

Type 2 diabetes mellitus (T2D) affects millions of people around the world, and its complications have serious health consequences. In addition to external factors, the causes of morbidity and increased risk were also sought in the variability of the human genome. A phenomenon that can answer these questions is the occurrence of single-nucleotide polymorphisms (SNP). They constitute a field for research into genetic determinants responsible for the increase in the risk of the discussed metabolic disease. This article presents the outline of two enzymes: metalloproteinases 2 and 9 (MMP-2, MMP-9), their biological activity and the effect caused by differences in individual alleles in the population, as well as the reports on the importance of these DNA sequence variations in the occurrence of diabetes mellitus type 2 and associated conditions. The results of the conducted research indicate a relationship between two MMP-2 polymorphisms (rs243865, rs243866) and two MMP-9 polymorphisms (rs3918242, rs17576) and the presence of T2D. This could offer a promising possibility to use them as predictive and diagnostic markers. However, due to the low number of reports, more research is needed to clearly confirm the link between these SNPs and diabetes.

Identification of missense SNP-mediated mutations in the regulatory sites of aldose reductase (ALR2) responsible for treatment failure in diabetic complications.

Scientific pieces of evidence indicate that the polymorphism in the ALR2 regulatory gene favors the susceptibility to diabetic complications (DCs). Previous studies have uncovered several single nucleotide polymorphisms (SNPs) in the ALR2 regulatory sites that negatively modulate the activity of this enzyme and eventually increase the risks of DCs. In view of this, the current study aimed at investigating whether the mutation as a resultant of missense SNPs in the regulatory site of ALR2 enzyme can also hamper the interactions of ALR2 inhibitors with the key amino acid residues in the ALR2 binding site. Around 202 SNPs in the ALR2 gene were reported in the dbSNP database. Out of these, eighteen SNPs that are responsible for point mutations in the regulatory sites of ALR2 enzyme were identified and considered for the study. Identified SNPs were then categorized as stabilizing or destabilizing using various in silico tools and webservers. The resulting mutational constructs of ALR2 were further probed for their influence on the binding affinities and binding modes with well-known ALR2 inhibitors using structure-based analyses. This study identified three destabilizing SNPs, i.e., rs779176563 (C298S), rs1392886142 (G16A), and rs1407261115 (A245T), that lead to the compromised response to most of the ALR2 inhibitors which are in clinical trials. On the other hand, treatment with these ALR2 inhibitors may benefit the population which carries missense SNPs rs748119899, rs1402962430, and rs1467939858 that code for W219S, Q183V, and S214A, respectively. Overall findings of the study suggest that one SNP in the inhibitor site and two SNPs in the co-factor site of ALR2 may be responsible for the low efficacy and unsuccessful journey of ALR2 inhibitors in the clinical trials.

Circular RNAs in diabetes mellitus and its complications.

Diabetes mellitus (DM) is an endocrine disorder characterized by a relative or absolute lack of insulin due to the dysfunction or destruction of ß-cells. DM is one of the fastest growing challenges to global health in the 21st century and places a tremendous burden on affected individuals and their families and countries. Although insulin and antidiabetic drugs have been used to treat DM, a radical cure for the disease is unavailable. The pathogenesis of DM remains unclear. Emerging roles of circular RNAs (circRNAs) in DM have become a subject of global research. CircRNAs have been verified to participate in the onset and progression of DM, implying their potential roles as novel biomarkers and treatment tools. In the present review, we briefly introduce the characteristics of circRNAs. Next, we focus on specific roles of circRNAs in type 1 diabetes mellitus, type 2 diabetes mellitus, gestational diabetes mellitus and diabetes-associated complications.

Gene Networks of Hyperglycemia, Diabetic Complications, and Human Proteins Targeted by SARS-CoV-2: What Is the Molecular Basis for Comorbidity?

People with diabetes are more likely to have severe COVID-19 compared to the general population. Moreover, diabetes and COVID-19 demonstrate a certain parallelism in the mechanisms and organ damage. In this work, we applied bioinformatics analysis of associative molecular networks to identify key molecules and pathophysiological processes that determine SARS-CoV-2-induced disorders in patients with diabetes. Using text-mining-based approaches and ANDSystem as a bioinformatics tool, we reconstructed and matched networks related to hyperglycemia, diabetic complications, insulin resistance, and beta cell dysfunction with networks of SARS-CoV-2-targeted proteins. The latter included SARS-CoV-2 entry receptors (ACE2 and DPP4), SARS-CoV-2 entry associated proteases (TMPRSS2, CTSB, and CTSL), and 332 human intracellular proteins interacting with SARS-CoV-2. A number of genes/proteins targeted by SARS-CoV-2 (ACE2, BRD2, COMT, CTSB, CTSL, DNMT1, DPP4, ERP44, F2RL1, GDF15, GPX1, HDAC2, HMOX1, HYOU1, IDE, LOX, NUTF2, PCNT, PLAT, RAB10, RHOA, SCARB1, and SELENOS) were found in the networks of vascular diabetic complications and insulin resistance. According to the Gene Ontology enrichment analysis, the defined molecules are involved in the response to hypoxia, reactive oxygen species metabolism, immune and inflammatory response, regulation of angiogenesis, platelet degranulation, and other processes. The results expand the understanding of the molecular basis of diabetes and COVID-19 comorbidity.

Novel Subgroups of Type 2 Diabetes Display Different Epigenetic Patterns That Associate With Future Diabetic Complications.

OBJECTIVE: Type 2 diabetes (T2D) was recently reclassified into severe insulin-deficient diabetes (SIDD), severe insulin-resistant diabetes (SIRD), mild obesity-related diabetes (MOD), and mild age-related diabetes (MARD), which have different risk of complications. We explored whether DNA methylation differs between these subgroups and whether subgroup-unique methylation risk scores (MRSs) predict diabetic complications. RESEARCH DESIGN AND METHODS: Genome-wide DNA methylation was analyzed in blood from subjects with newly diagnosed T2D in discovery and replication cohorts. Subgroup-unique MRSs were built, including top subgroup-unique DNA methylation sites. Regression models examined whether MRSs associated with subgroups and future complications. RESULTS: We found epigenetic differences between the T2D subgroups. Subgroup-unique MRSs were significantly different in those patients allocated to each respective subgroup compared with the combined group of all other subgroups. These associations were validated in an independent replication cohort, showing that subgroup-unique MRSs associate with individual subgroups (odds ratios 1.6-6.1 per 1-SD increase, P < 0.01). Subgroup-unique MRSs were also associated with future complications. Higher MOD-MRS was associated with lower risk of cardiovascular (hazard ratio [HR] 0.65, P = 0.001) and renal (HR 0.50, P < 0.001) disease, whereas higher SIRD-MRS and MARD-MRS were associated with an increased risk of these complications (HR 1.4-1.9 per 1-SD increase, P < 0.01). Of 95 methylation sites included in subgroup-unique MRSs, 39 were annotated to genes previously linked to diabetes-related traits, including TXNIP and ELOVL2. Methylation in the blood of 18 subgroup-unique sites mirrors epigenetic patterns in tissues relevant for T2D, muscle and adipose tissue. CONCLUSIONS: We identified differential epigenetic patterns between T2D subgroups that associated with future diabetic complications. These data support a reclassification of diabetes and the need for precision medicine in T2D subgroups.