Diabetic Vascular Complications Research Articles

Significant liver fibrosis, as assessed by fibroscan, is independently associated with chronic vascular complications of type 2 diabetes: A multicenter study

AimsThe aim of this study was to investigate whether controlled attenuation parameter (CAP) and liver stiffness measurement (LSM), as assessed by vibration-controlled transient elastography (VCTE), are associated with chronic vascular complications of diabetes mellitus type 2 (T2DM). MethodsWe studied 442 outpatients with established T2DM, and who underwent VCTE and extensive assessment of chronic vascular complications of diabetes. ResultsA quarter of analyzed patients had a previous history of myocardial infarction and/or ischemic stroke, and about half of them had at least one microvascular complication (chronic kidney disease (CKD), retinopathy or polyneuropathy). The prevalence of liver steatosis (i.e., CAP ≥ 238 dB/m) and significant liver fibrosis (i.e., LSM ≥ 7.0/6.2 kPa) was 84.2% and 46.6%, respectively. Significant liver fibrosis was associated with an increased likelihood of having myocardial infarction (adjusted-odds ratio 6.61, 95%CI 1.66–37.4), peripheral polyneuropathy (adjusted-OR 4.55, 95%CI 1.25–16.6), CKD (adjusted-OR 4.54, 95%CI 1.24–16.6) or retinopathy (adjusted-OR 1.81, 95%CI 1.62–1.97), independently of cardiometabolic risk factors, diabetes-related variables, and other potential confounders. Liver steatosis was not independently associated with any macro-/microvascular diabetic complications. ConclusionsSignificant liver fibrosis is strongly associated with the presence of macro-/microvascular complications in patients with T2DM. These results offer a new perspective on the follow-up of people with T2DM.

384-P: Text Mining and Bioinformatic Identification of Genes Linking Glycemic Variability and Impaired Angiogenesis in Diabetes

The Aim: to identify key genes involved in angiogenic response and influenced by enhanced glycemic variability (GV) in diabetes. Methods: Text-mining of Medline/Pubmed abstracts, reconstruction and analysis of gene networks related to GV and angiogenesis was performed by ANDSystem (www-bionet.sscc.ru/and/cell/). Genes associated with both hyperglycemia and hypoglycemia were attributed to be GV-related. Compounds targeting the identified genes were found using the TTD database (db.idrblab.net/ttd/). Results: The set of genes implicated in angiogenesis that are up- or down-regulated by both hyperglycemia and hyperglycemia and compounds targeting and regulating these genes are summarized in the Table. Conclusions: The obtained results support the hypothesis that detrimental effect of enhanced GV in diabetes could be realized by up- or down-regulation of the genes involved in angiogenic response. The role of the identified genes and compounds influencing their activity in the development of diabetic vascular complications requires experimental testing. Disclosure O. V. Saik: None. V. Klimontov: Advisory Panel; Self; Boehringer Ingelheim International GmbH, Sanofi, Research Support; Self; Boehringer Ingelheim International GmbH, Speaker’s Bureau; Self; AstraZeneca, Medtronic. Funding Russian Science Foundation (20-15-00057)

Patients with Diabetes Complicated by Peripheral Artery Disease: the Current State of Knowledge on Physiotherapy Interventions.

Diabetes mellitus (DM) is one of the major public health problems that account for morbidity, mortality, and disability worldwide. The presence of DM increases the risk of peripheral artery disease (PAD), as well as accelerates its course, making these patients more susceptible to ischemic events and impaired functional status. Unfortunately, alternative treatments for vascular complications in diabetes are poorly researched. Physiotherapy (kinesitherapy combined with different physical therapy agents) in individuals with DM and coexisting PAD may offer an important complementary therapy alternative. Early therapeutic measures can significantly improve patient outcomes, reduce cardiovascular risk, and improve daily life quality. The article provides an update on the current state of knowledge on physiotherapy interventions in the course of DM in patients with coexisting PAD.

A 5-year assessment of the epidemiology and natural history of possible diabetes in remission

IntroductionType 2 diabetes is considered a chronic and progressive disease. The term diabetes in remission has no consensus definition and the question whether diabetes “remission” or “cure” can achieve any long-term benefits in people with type 2 diabetes remains unclear. The aim of our study was a review of our district wide diabetes population to determine the epidemiology and clinical characteristics of those who had a diagnosis of diabetes but did not meet the diagnostic criteria for diabetes at the point of assessment in 2014 and then to review their diabetes outcomes over a 5-year time frame. MethodsIn a whole population based non-interventional epidemiological study amongst 17,308 people with diabetes, we identified 991 with diet treated type 2 diabetes who met the baseline criteria for diabetes in remission (HbA1c < 48 mmol/mol (6.5%)). Over the next 5 years, 385 (39%) people had a cumulative HbA1c attainment of <48 mmol/mol (6.5%) and remained free of diabetes medication. ResultsIn this erstwhile remission group only 130 (13%) were free of any vasculopathy, whilst 255 (26%) had some form of micro or macrovascular disease, of which 64 people had been without micro or macrovascular vascular complications at baseline. Only 20 people had a HbA1c consistently ≤37 mmol/mol (5.7%) who were free of diabetes vascular complications and of diabetes medication. ConclusionsThe definition of ‘diabetes in remission’ remains unclear most especially regarding the inclusion of baseline prevalent or incident macro or microvascular disease, the durability of potential remission is poor, and the likelihood of cure is remote.

Habitual Miso (Fermented Soybean Paste) Consumption Is Associated with Glycemic Variability in Patients with Type 2 Diabetes: A Cross-Sectional Study.

Glycemic control, including glycemic variability, is important for the prevention of diabetic vascular complications in patients with type 2 diabetes mellitus (T2DM). There was an association between miso soup intake and insulin resistance. However, the relationship between habitual miso consumption and glycemic control, including glycemic variability, in patients with T2DM remains unknown. We defined people without habitual miso consumption if they did not consume miso soup at all in a day. The average, standard deviation (SD), and coefficient of variation (CV), calculated as CV = (SD/average HbA1c) × 100 (%), of hemoglobin (Hb) A1c levels were evaluated. The proportions of habitual miso consumption of male and female were 88.1% and 82.3%, respectively. The average (7.0 [6.4–7.5] vs. 7.3 [6.8–8.4] %, p = 0.009), SD (0.21 [0.12–0.32] vs. 0.37 [0.20–0.72], p = 0.004), and CV (0.03 [0.02–0.04] vs. 0.05 [0.03–0.09], p = 0.005) of HbA1c levels in female with habitual miso consumption were lower than those of female without. Moreover, habitual miso consumption correlated with average (β = −0.251, p = 0.009), SD (β = −0.175, p = 0.016), and CV (β = −0.185, p = 0.022) of HbA1c levels after adjusting for covariates. However, no association between habitual miso consumption and any glycemic parameters was shown among male. This study clarified the association between habitual miso consumption and good glycemic control, including glycemic variability, in female, but not in male.

Pterostilbene prevents methylglyoxal-induced cytotoxicity in endothelial cells by regulating glyoxalase, oxidative stress and apoptosis

Methylglyoxal (MGO), a cytotoxic byproduct of glycolysis in biological systems, can induce endothelial cells dysfunction, implicated in diabetic vascular complications. Pterostilbene (PTS), a naturally occurring resveratrol derivative, is involved in various pharmacological activities. This study aimed to explore the effects of PTS on MGO induced cytotoxicity in human umbilical vein endothelial cells (HUVECs) and the underlying mechanisms for the first time. In the current study, it has been demonstrated that PTS could enhance the level of glyoxalase 1 (GLO-1) and elevate glutathione (GSH) content to active the glyoxalase system, resulting in elimination of the toxic MGO as well as advanced glycation end products (AGEs) in HUVECs. Meanwhile, PTS could also suppress oxidative stress and thus exert cytoprotective effects by elevating Nrf2 nuclear translocation and the corresponding down-stream antioxidant enzymes in MGO induced HUVECs. In addition, PTS could alleviate MGO induced apoptosis in HUVECs via inhibition of oxidative stress and associated downstream mitochondria-dependent signaling apoptotic cascades, as characterized by preventing caspases family activation. Taken together, these findings suggest that PTS could protect against MGO induced endothelial cell cytotoxicity by regulating glyoxalase, oxidative stress and apoptosis, suggesting that PTS could be beneficial in the treatment of diabetic vascular complications.

Dysregulation of nitric oxide synthases during early and late pathophysiological conditions of diabetes mellitus leads to amassing of microvascular impedement.

Diabetes is a major killer worldwide and its unprecedented rise poses a serious threat to mankind. According to recent estimation, 387million people worldwide are affected from the disease with a prevalence rate of 8.3 and 46.3 % still remains undiagnosed. Important characteristics of diabetes are abnormalities of the physiological signalling functions of reactive oxygen species and reactive nitrogen species. Increased oxidative stress contributes to the activation of stress-sensitive intracellular signalling pathways and the development of gene products that trigger cellular damage and contribute to the vascular complications of diabetes. Growing evidence from studies into many diseases suggests that the pathogenesis of diabetes, obesity, cancer, ageing, inflammation, neurodegenerative disorders, hypertension, apoptosis, cardiovascular diseases, and heart failure are correlated with oxidative stress. This leads to cell metabolism and cell-cell homeostasis to be complexly dysregulated. This review focuses to investigate the status of oxidative stress, nitric oxide and reactive species in early and diabetes. Significance of nitric oxide synthases Evidences has accumulated indicating that the generation of reactive oxygen species (oxidative stress) may play an important role in the etiology of diabetic complications thus attention was given on the reactive oxygen and reactive nitrogen species and their potential role in pathogenesis. Additionally, the therapeutic advances in diabetes management are included. Nanotechnology, statins and stem cell technology are some techniques which can be considered to have a possible future in the treatment sector of diabetes.

Mitophagy in Human Diseases.

Mitophagy is a selective autophagic process, essential for cellular homeostasis, that eliminates dysfunctional mitochondria. Activated by inner membrane depolarization, it plays an important role during development and is fundamental in highly differentiated post-mitotic cells that are highly dependent on aerobic metabolism, such as neurons, muscle cells, and hepatocytes. Both defective and excessive mitophagy have been proposed to contribute to age-related neurodegenerative diseases, such as Parkinson’s and Alzheimer’s diseases, metabolic diseases, vascular complications of diabetes, myocardial injury, muscle dystrophy, and liver disease, among others. Pharmacological or dietary interventions that restore mitophagy homeostasis and facilitate the elimination of irreversibly damaged mitochondria, thus, could serve as potential therapies in several chronic diseases. However, despite extraordinary advances in this field, mainly derived from in vitro and preclinical animal models, human applications based on the regulation of mitochondrial quality in patients have not yet been approved. In this review, we summarize the key selective mitochondrial autophagy pathways and their role in prevalent chronic human diseases and highlight the potential use of specific interventions.

Pemafibrate, A Novel Selective Peroxisome Proliferator-Activated Receptor α Modulator, Reduces Plasma Eicosanoid Levels and Ameliorates Endothelial Dysfunction in Diabetic Mice

Aims: Various pathological processes related to diabetes cause endothelial dysfunction. Eicosanoids derived from arachidonic acid (AA) have roles in vascular regulation. Fibrates have recently been shown to attenuate vascular complications in diabetics. Here we examined the effects of pemafibrate, a selective peroxisome proliferator-activated receptor α modulator, on plasma eicosanoid levels and endothelial function in diabetic mice. Methods: Diabetes was induced in 7-week-old male wild-type mice by a single injection of streptozotocin (150 mg/kg). Pemafibrate (0.3 mg/kg/day) was administered orally for 3 weeks. Untreated mice received vehicle. Circulating levels of eicosanoids and free fatty acids were measured using both gas and liquid chromatography-mass spectrometry. Endothelium-dependent and endothelium-independent vascular responses to acetylcholine and sodium nitroprusside, respectively, were analyzed. Results: Pemafibrate reduced both triglyceride and non-high-density lipoprotein-cholesterol levels ( P ＜0.01), without affecting body weight. It also decreased circulating levels of AA ( P ＜0.001), thromboxane B 2 ( P ＜0.001), prostaglandin E 2 , leukotriene B 4 ( P ＜0.05), and 5-hydroxyeicosatetraenoic acid ( P ＜0.001), all of which were elevated by the induction of diabetes. In contrast, the plasma levels of 15-deoxy-Δ 12,14 -prostaglandin J 2 , which declined following diabetes induction, remained unaffected by pemafibrate treatment. In diabetic mice, pemafibrate decreased palmitic acid (PA) and stearic acid concentrations ( P ＜0.05). Diabetes induction impaired endothelial function, whereas pemafibrate ameliorated it ( P ＜0.001). The results of ex vivo experiments indicated that eicosanoids or PA impaired endothelial function. Conclusion: Pemafibrate diminished the levels of vasoconstrictive eicosanoids and free fatty acids accompanied by a reduction of triglyceride. These effects may be associated with the improvement of endothelial function by pemafibrate in diabetic mice.

Hypolipidemic Effects of Rosa Damascena Mill. Extract in Streptozotocin-induced Diabetic Rats

Background: Diabetes mellitus is a chronic hyperglycemic condition with a lot of complication which canlead to death. Vascular complication in diabetes commonly caused by dyslipidemia which characterizedby decreased HDL, elevated LDL, Cholesterol and Triglyceride. Rosa damascena- an ornamental plantthoughts to have anti-hyperglycemia and antioxidant effects because of its large amount of polyphenoliccomponents . This study analyzed hypolipidemic activity properties of an ethanol extract of Rosa damascenaby measuring the lipid profile using various doses. Methods: This research is experimental study withrandomized post-test only control group design. Twenty male Wistar rats divided into 5 groups; The groupswere Healthy Control Group (HCG), Diabetes Group (DG), and Extract Group: P1 (250 mg/kgBW), P2(500 mg/kgBW), P3 (1000 mg/kgBW). All treatment groups were injected by single-dose streptozotocin50 mg/kgBW to induce diabetes, and given the Rosa damascena ethanolic extract oral treatment for 2weeks. Statistical results showed that Rosa damascena significantly decrease cholesterol (58.2±15.19), LDL(11±2.44) optimally in dose 250 mg/KgBW and triglyceride (96.7±44.2) optimally in dose 500 mg/kgBWafter 14 days. Conclusion: Rosa damascena extract seems to be great candidate for anti-hyperlipidemicdrugs.

Association of Combined TCF7L2 and KCNQ1 Gene Polymorphisms with Diabetic Micro- and Macrovascular Complications in Type 2 Diabetes Mellitus.

BackgroundVascular complications are the major morbid consequences of type 2 diabetes mellitus (T2DM). The transcription factor 7-like 2 (TCF7L2), potassium voltage-gated channel subfamily Q member 1 (KCNQ1), and inwardly-rectifying potassium channel, subfamily J, member 11 gene (KCNJ11) are common T2DM susceptibility genes in various populations. However, the associations between polymorphisms in these genes and diabetic complications are controversial. This study aimed to investigate the effects of combined gene-polymorphisms within TCF7L2, KCNQ1, and KCNJ11 on vascular complications in Thai subjects with T2DM.MethodsWe conducted a case-control study comprising 960 T2DM patients and 740 non-diabetes controls. Single nucleotide polymorphisms in TCF7L2, KCNQ1, and KCNJ11 were genotyped and evaluated for their association with diabetic vascular complications.ResultsThe gene variants TCF7L2 rs290487-T, KCNQ1 rs2237892-C, and KCNQ1 rs2237897-C were associated with increased risk of T2DM. TCF7L2 rs7903146-C, TCF7L2 rs290487-C, KCNQ1 rs2237892-T, and KCNQ1 rs2237897-T revealed an association with hypertension. The specific combination of risk-alleles that have effects on T2DM and hypertension, TCF7L2 rs7903146-C, KCNQ1 rs2237892-C, and KCNQ1 rs2237897-T, as genetic risk score (GRS), pronounced significant association with coronary artery disease (CAD), cumulative nephropathy and CAD, and cumulative microvascular and macrovascular complications (respective odds ratios [ORs] with 95% confidence interval [95% CI], comparing between GRS 2–3 and GRS 5–6, were 7.31 [2.03 to 26.35], 3.92 [1.75 to 8.76], and 2.33 [1.13 to 4.79]).ConclusionThis study demonstrated, for the first time, the effect conferred by specific combined genetic variants in TCF7L2 and KCNQ1 on diabetic vascular complications, predominantly with nephropathy and CAD. Such a specific pattern of gene variant combination may implicate in the progression of T2DM and life-threatening vascular complications.

PAI-1 in Diabetes: Pathophysiology and Role as a Therapeutic Target.

Hypofibrinolysis is a key abnormality in diabetes and contributes to the adverse vascular outcome in this population. Plasminogen activator inhibitor (PAI)-1 is an important regulator of the fibrinolytic process and levels of this antifibrinolytic protein are elevated in diabetes and insulin resistant states. This review describes both the physiological and pathological role of PAI-1 in health and disease, focusing on the mechanism of action as well as protein abnormalities in vascular disease with special focus on diabetes. Attempts at inhibiting protein function, using different techniques, are also discussed including direct and indirect interference with production as well as inhibition of protein function. Developing PAI-1 inhibitors represents an alternative approach to managing hypofibrinolysis by targeting the pathological abnormality rather than current practice that relies on profound inhibition of the cellular and/or acellular arms of coagulation, and which can be associated with increased bleeding events. The review offers up-to-date knowledge on the mechanisms of action of PAI-1 together with the role of altering protein function to improve hypofirbinolysis. Developing PAI-1 inhibitors may form for the basis of future new class of antithrombotic agents that reduce vascular complications in diabetes.

Phloroglucinol and dieckol isolated from Ecklonia cava suppress impaired diabetic angiogenesis; A study of in-vitro and in-vivo

Abnormalities in angiogenesis that are associated with diabetes may contribute to vascular complications and result in disabilities and death. Furthermore, an imbalance in angiogenesis in different tissues, including the retina and kidney, can play a role in the pathogenesis of diabetic microvascular complications. Phlorotannins, such as phloroglucinol (PG) and dieckol (DK), which are found in Ecklonia cava exhibit antioxidant and anti-inflammatory activities that improve endothelial function in hypertension. However, reports on the effects of these compounds on diabetes-induced angiogenesis in vivo and in vitro are scarce. In this study, we assessed the antiangiogenic effects of PG and DK on endothelial cells treated with a high concentration of glucose to mimic angiogenesis. In addition, we sought to determine the effects of these compounds on cell proliferation, cell migration, and capillary formation. In silico docking of PG and DK into VEGFR-2 revealed their potential as therapeutic agents against angiogenesis. Further, both compounds were identified to inhibit the formation of the retinal vessel in transgenic zebrafish (flk:EGFP) embryos under high glucose conditions. These findings suggested that PG and DK derived from E. cava are potential inhibitors of angiogenesis in diabetic vascular complications and could, therefore, be used to develop angiogenic agents.

POSTN promotes diabetic vascular calcification by interfering with autophagic flux

Autophagy is a lysosomal degradative process that is closely related to the pathogenesis of vascular calcification. Recent evidence suggests that periostin (POSTN) is a unique extracellular matrix protein that is associated with diabetic vascular complications. The aim of current study is to investigate the role of POSTN in diabetic vascular calcification and the underlying mechanisms. Results showed that POSTN was highly upregulated in both calcified arteries of diabetic rats and AGEs-BSA mediated vascular smooth muscle cell (VSMC) calcification. POSTN blocked autophagic flux during the diabetic calcification process, as evidenced by increased protein expression of Beclin1, LC3-II, and P62, as well as the co-localization of LC3-II and LAMP1. Inhibition of POSTN alleviated AGEs-BSA-induced autophagic flux blockade, thereby attenuating AGEs-BSA-induced VSMC calcification. Mechanistically, the upregulation of POSTN impaired the fusion of autophagosomes and lysosome and resulted in the autophagic flux blockade in AGEs-BSA-treated VSMC. Furthermore, this autophagic blockade was intracellular ROS-dependent. In summary, this study uncovered a novel mechanism of POSTN in autophagy regulation of diabetic vascular calcification.

MicroRNA-9 rescues hyperglycemia-induced endothelial cell dysfunction and promotes arteriogenesis through downregulating Notch1 signaling.

Hyperglycemia-induced endothelial dysfunction plays a major role in the pathogenesis of diabetic vascular complications. MicroRNAs are potential therapeutic agents to improve hyperglycemia-induced endothelial dysfunction. This study examined the relationship of miR-9 with Notch1 signaling in hyperglycemia-induced endothelial dysfunction. Human umbilical vein endothelial cells (HUVECs) were exposed to 30mM glucose concentration. Cell viability including proliferation, adhesion, migration and tube formation was significantly impaired. Quantitative real time polymerase chain reaction (qRT-PCR) or Western blot demonstrated that miR-9 expression remarkably decreased and expression of Notch1 and its effectors (Hes1, Hey1, Hey2) were upregulated. Transfection with miR-9 improved cell function, inhibited mRNA and protein expression of Notch1 and its effectors. Although basal expression of the arterial endothelium biomarker Ephrin B2 was almost undetectable in HUVECs, double-label immunofluorescence revealed that transfection with miR-9 upregulated Ephrin B2 expression. By contrast, such protective effects of miR-9 overexpression were eliminated due to use of miR-9 inhibitor. Dual luciferase assay further confirmed a significant inverse correlation between miR-9 and Notch1. In addition, Notch1 overactiviation was mimicked in HUVECs by transfecting with Notch1 intracellular domain (NICD1). MiR-9 significantly inhibited NICD1 mRNA expression and alleviated hyperglycemia-induced injury of the NICD1-overexpressing cells. Taken together, our data support upregulating miR-9 expression as a potential therapeutic strategy to antagonize hyperglycemia-induced injury by inhibiting Notch1 signaling.

Alpha-mangostin improves endothelial dysfunction in db/db mice through inhibition of aSMase/ceramide pathway.

Diabetic vascular complications are the leading causes of death and disability in patients with diabetes. Alpha‐mangostin has been reported to have anti‐diabetic capacity in recent years. Here, we investigated the protective function of alpha‐mangostin on endothelium in vitro and in vivo experiments. We also observed that alpha‐mangostin improved impaired endothelium‐dependent vasodilation (EDV) of diabetic animals while it limited the aSMase/ceramide pathway and up‐regulated eNOS/NO pathway in aortas from diabetic mice. Meanwhile, alpha‐mangostin inhibited elevated aSMase/ceramide pathway and reversed impaired EDV induced by high glucose in isolated mouse aortas. In addition, alpha‐mangostin increased phosphorylation of eNOS and NO production in high glucose‐treated aortas. Alpha‐mangostin normalized high glucose‐induced activation of aSMase/ceramide pathway and improved eNOS/NO pathway in endothelial cells with high glucose. In conclusion, alpha‐mangostin regulates eNOS/NO pathway and improves EDV in aortas of diabetic mice through inhibiting aSMase activity and endogenous ceramide accumulation.

Plasma Targeted Metabolomics Analysis for Amino Acids and Acylcarnitines in Patients with Prediabetes, Type 2 Diabetes Mellitus, and Diabetic Vascular Complications.

BackgroundWe hypothesized that specific amino acids or acylcarnitines would have benefits for the differential diagnosis of diabetes. Thus, a targeted metabolomics for amino acids and acylcarnitines in patients with diabetes and its complications was carried out.MethodsA cohort of 54 normal individuals and 156 patients with type 2 diabetes mellitus and/or diabetic complications enrolled from the First Affiliated Hospital of Jinzhou Medical University was studied. The subjects were divided into five main groups: normal individuals, impaired fasting glucose, overt diabetes, diabetic microvascular complications, and diabetic peripheral vascular disease. The technique of tandem mass spectrometry was applied to obtain the plasma metabolite profiles. Metabolomics multivariate statistics were applied for the metabolic data analysis and the differential metabolites determination.ResultsA total of 10 cross-comparisons within diabetes and its complications were designed to explore the differential metabolites. The results demonstrated that eight comparisons existed and yielded significant metabolic differences. A total number of 24 differential metabolites were determined from six selected comparisons, including up-regulated amino acids, down-regulated medium-chain and long-chain acylcarnitines. Altered differential metabolites provided six panels of biomarkers, which were helpful in distinguishing diabetic patients.ConclusionOur results demonstrated that the biomarker panels consisted of specific amino acids and acylcarnitines which could reflect the metabolic variations among the different stages of diabetes and might be useful for the differential diagnosis of prediabetes, overt diabetes and diabetic complications.

Elevated HDL-bound miR-181c-5p level is associated with diabetic vascular complications in Australian Aboriginal people.

Diabetes is a major burden on Australia's Indigenous population, with high rates of disease and vascular complications. Diabetic vascular complications are associated with impaired ischaemia-driven angiogenesis. MicroRNAs (miRNAs) are key players in the regulation of angiogenesis. HDL-cholesterol (HDL-c) levels are inversely associated with the risk of developing diabetic complications and HDL can carry miRNAs. HDL-miRNA profiles differ in disease states and may present as biomarkers with the capacity to act as bioactive signalling molecules. Recent studies have demonstrated that HDL becomes dysfunctional in a diabetic environment, losing its vasculo-protective effects and becoming more pro-atherogenic. We sought to determine whether HDL-associated miRNA profiles and HDL functionality were predictive of the severity of diabetic vascular complications in Australia's Indigenous population. HDL was isolated from plasma samples from Indigenous participants without diabetes ('Healthy'), with type 2 diabetes mellitus ('T2DM') and with diabetes-associated macrovascular complications (specifically peripheral artery disease, 'T2DM+Comp'). To assess HDL angiogenic capacity, human coronary artery endothelial cells were treated with PBS, reconstituted HDL (rHDL, positive control) or isolated HDL and then exposed to high-glucose (25mmol/l) conditions. The expression levels of two anti-angiogenic miRNAs (miR-181c-5p and miR-223-3p) and one pro-angiogenic miRNA (miR-27b-3p) were measured in the HDL fraction, plasma and treated human coronary artery endothelial cells by quantitative real-time PCR. In vitro endothelial tubule formation was assessed using the Matrigel tubulogenesis assay. Strikingly, we found that the levels of the anti-angiogenic miRNA miR-181c-5p were 14-fold higher (1454 ± 1346%) in the HDL from Aboriginal people with diabetic complications compared with both the Healthy (100 ± 121%, p < 0.05) and T2DM (82 ± 77%, p < 0.05) groups. Interestingly, we observed a positive correlation between HDL-associated miR-181c-5p levels and disease severity (p = 0.0020). Under high-glucose conditions, cells treated with rHDL, Healthy HDL and T2DM HDL had increased numbers of tubules (rHDL: 136 ± 8%, p < 0.01; Healthy HDL: 128 ± 6%, p < 0.01; T2DM HDL: 124 ± 5%, p < 0.05) and branch points (rHDL: 138 ± 8%, p < 0.001; Healthy HDL: 128 ± 6%, p < 0.01; T2DM HDL: 127 ± 5%, p < 0.01) concomitant with elevations in mRNA levels of the key hypoxia angiogenic transcription factor HIF1A (rHDL: 140 ± 10%, p < 0.01; Healthy HDL: 136 ± 8%, p < 0.01; T2DM HDL: 133 ± 9%, p < 0.05). However, this increase in angiogenic capacity was not observed in cells treated with T2DM + Comp HDL (tubule numbers: 113 ± 6%, p = 0.32; branch points: 113 ± 5%, p = 0.28; HIF1A: 117 ± 6%, p = 0.43), which could be attributed to the increase in cellular miR-181c-5p levels (T2DM + Comp HDL: 136 ± 7% vs PBS: 100 ± 9%, p < 0.05). In conclusion, HDL from Aboriginal people with diabetic complications had reduced angiogenic capacity. This impairment is associated with an increase in the expression of anti-angiogenic miR-181c-5p. These findings provide the rationale for a new way to better inform clinical diagnosis of disease severity with the potential to incorporate targeted, personalised HDL-miRNA intervention therapies to prevent further development of, or to reverse, diabetic vascular complications in Australian Aboriginal people.

Protein glycation – biomarkers of metabolic dysfunction and early-stage decline in health in the era of precision medicine

Protein glycation provides a biomarker in widespread clinical use, glycated hemoglobin HbA1c (A1C). It is a biomarker for diagnosis of diabetes and prediabetes and of medium-term glycemic control in patients with established diabetes. A1C is an early-stage glycation adduct of hemoglobin with glucose; a fructosamine derivative. Glucose is an amino group-directed glycating agent, modifying N-terminal and lysine sidechain amino groups. A similar fructosamine derivative of serum albumin, glycated albumin (GA), finds use as a biomarker of glycemic control, particularly where there is interference in use of A1C. Later stage adducts, advanced glycation endproducts (AGEs), are formed by the degradation of fructosamines and by the reaction of reactive dicarbonyl metabolites, such as methylglyoxal. Dicarbonyls are arginine-directed glycating agents forming mainly hydroimidazolone AGEs. Glucosepane and pentosidine, an intense fluorophore, are AGE covalent crosslinks. Cellular proteolysis of glycated proteins forms glycated amino acids, which are released into plasma and excreted in urine. Development of diagnostic algorithms by artificial intelligence machine learning is enhancing the applications of glycation biomarkers. Investigational glycation biomarkers are in development for: (i) healthy aging; (ii) risk prediction of vascular complications of diabetes; (iii) diagnosis of autism; and (iv) diagnosis and classification of early-stage arthritis. Protein glycation biomarkers are influenced by heritability, aging, decline in metabolic, vascular, renal and skeletal health, and other factors. They are applicable to populations of differing ethnicities, bridging the gap between genotype and phenotype. They are thereby likely to find continued and expanding clinical use, including in the current era of developing precision medicine, reporting on multiple pathogenic processes and supporting a precision medicine approach.

Vascular complications of diabetes: natural history and corresponding risks of dementia in a national cohort of adults with diabetes

This study aimed to determine the trajectory of diabetic vascular diseases and to investigate the association between vascular diseases and dementia. We included adults aged ≥ 50years with newly diagnosed type 2 diabetes (n = 173,118) from 2001 to 2005 who were followed-up until December 31, 2013 in the Taiwan's National Health Insurance Research Database. Multivariable Cox regression models were constructed to estimate hazard ratios (HRs) and confidence limits (CLs) for all-cause dementia in relation to the number, types, and occurrence patterns of vascular disease. Within 1year of diabetes diagnosis, 26.3% of adults developed their first vascular disease. During the 1,864,279 person-years offollow-up, 17,426 adults had all-cause dementia, corresponding to an incidence of 97.9 cases/10,000 person-years in 127,718 adults with at least one vascular disease and 67.5 cases/10,000 person-years in 45,400 adults without vascular diseases. Across all age groups, adults who subsequently developed a vascular disease in two one-year windows since diabetes diagnosis had the highest incidence of all-cause dementia. In comparison with adults without vascular diseases, HR for all-cause dementia was 1.99 (CL: 1.92-2.07) for those with one vascular disease only; 2.04 (CL: 1.98-2.13) for two or more vascular diseases; 3.56 (CL: 3.44-3.70) for stroke only; and 2.06 (CL: 1.99-2.14) for neuropathy alone. Similar associations were also observed with a smaller magnitude for adults with nephropathy, retinopathy, cardiovascular disease, or peripheral arterial disease. Patients with diabetes-related complications, particularly stroke and neuropathy, and those with rapidly developed vascular diseases appeared to have a high risk of dementia.