Impact of Glycemic Variability on Chromatin Remodeling, Oxidative Stress, and Endothelial Dysfunction in Patients With Type 2 Diabetes and With Target HbA1c Levels

Relationship between hemoglobin glycation index and risk of hypoglycemia in type 2 diabetes with time-in-range in target

BACKGROUND

In patients with type 2 diabetes mellitus (T2DM), the risk of hypoglycemia also occurs in at a time-in-range (TIR) of > 70%. The hemoglobin glycation index (HGI) is considered the best single factor for predicting hypoglycemia, and offers new perspectives for the individualized treatment of patients with well-controlled blood glucose levels that are easily ignored in clinical settings.

AIM

To investigate the relationship between HGI and hypoglycemia and the implications of HGI on hypoglycemia in T2DM with TIR > 70%.

METHODS

All participants underwent a 7-days continuous glucose monitoring (CGM) using a retrospective CGM system. We obtained glycemic variability indices using the CGM system. We defined HGI as laboratory hemoglobin A1c minus the glucose management indicator. Patients were categorized into low HGI (HGI < 0.5) and high HGI groups (HGI ≥ 0.5) according to HGI median (0.5). Logistic regression and receiver operating characteristic curve analyses were used to determine the risk factors for hypoglycemia.

RESULTS

We included 129 subjects with T2DM (54.84 ± 12.56 years, 46% male) in the study. Median TIR score was 90%. The high HGI group exhibited lower TIR and greater time below range with higher hemoglobin A1c than the low HGI group; this suggests more glycemic excursions and an increased incidence of hypoglycemia in the high HGI group. Multivariate analyses revealed that mean blood glucose, standard deviation of blood glucose and HGI were independent risk factors for hypoglycemia. Receiver operating characteristic curve analysis indicated that the HGI was the best predictor of hypoglycemia. In addition, the optimal cut-off points for HGI, mean blood glucose, and standard deviation of blood glucose in predicting hypoglycemia were 0.5%, 7.2 mmol/L and 1.4 mmol/L respectively.

CONCLUSION

High HGI was significantly associated with greater glycemic excursions and increased hypoglycemia in patients with TIR > 70%. Our findings indicate that HGI is a reliable predictor of hypoglycemia in this population.

Update: the role of epigenetics in the metabolic memory of diabetic complications

Diabetes, a chronic disease characterized by hyperglycemia, is associated with significantly accelerated complications, including diabetic kidney disease (DKD), which increases morbidity and mortality. Hyperglycemia and other diabetes-related environmental factors such as overnutrition, sedentary lifestyles, and hyperlipidemia can induce epigenetic changes. Working alone or with genetic factors, these epigenetic changes that occur without alterations in the underlying DNA sequence, can alter the expression of pathophysiological genes and impair functions of associated target cells/organs, leading to diabetic complications like DKD. Notably, some hyperglycemia-induced epigenetic changes persist in target cells/tissues even after glucose normalization, leading to sustained complications despite glycemic control, so-called metabolic memory. Emerging evidence from in vitro and in vivo animal models and clinical trials with subjects with diabetes identified clear associations between metabolic memory and epigenetic changes including DNA methylation, histone modifications, chromatin structure, and noncoding RNAs at key loci. Targeting such persistent epigenetic changes and/or molecules regulated by them can serve as valuable opportunities to attenuate, or erase metabolic memory, which is crucial to prevent complication progression. Here, we review these cell/tissue-specific epigenetic changes identified to-date as related to diabetic complications, especially DKD, and the current status on targeting epigenetics to tackle metabolic memory. We also discuss limitations in current studies, including the need for more (epi)genome-wide studies, integrative analysis using multiple epigenetic marks and Omics datasets, and mechanistic evaluation of metabolic memory. Considering the tremendous technological advances in epigenomics, genetics, sequencing, and availability of genomic datasets from clinical cohorts, this field is likely to see considerable progress in the upcoming years.

HbA1c variability associated with dementia risk in people with type 2 diabetes

INTRODUCTION

Although poor glycemic control is associated with dementia, it is unknown if variability in glycemic control, even in those with optimal glycosylated hemoglobin A1c (HbA1c) levels, increases dementia risk.

METHODS

Among 171,964 people with type 2 diabetes, we evaluated the hazard of dementia association with long-term HbA1c variability using five operationalizations, including standard deviation (SD), adjusting for demographics and comorbidities.

RESULTS

The mean baseline age was 61 years (48% women). Greater HbA1c SD was associated with greater dementia hazard (adjusted hazard ratio = 1.15 [95% confidence interval: 1.12, 1.17]). In stratified analyses, higher HbA1c SD quintiles were associated with greater dementia hazard among those with a mean HbA1c < 6% (P = 0.0004) or 6% to 8% (P < 0.0001) but not among those with mean HbA1c ≥ 8% (P = 0.42).

DISCUSSION

Greater HbA1c variability is associated with greater dementia risk, even among those with HbA1c concentrations at ideal clinical targets. These findings add to the importance and clinical impact of recommendations to minimize glycemic variability.

HIGHLIGHTS

We observed a cohort of 171,964 people with type 2 diabetes (mean age 61 years). This cohort was based in Northern California between 1996 and 2018. We examined the association between glycosylated hemoglobin A1c (HbA1c) variability and dementia risk. Greater HbA1c variability was associated with greater dementia hazard. This was most evident among those with normal-low mean HbA1c concentrations.

What is the best predictor of mortality in patients with type 2 diabetes and chronic kidney disease: mean, variability of HbA1c or HbA1c-Hemoglobin ratio?

AIM

Limitations in the measurement of glycated hemoglobin (HbA1c) in patients with type 2 diabetes (T2D) and chronic kidney disease (CKD) result in uncertainty about the best predictor of mortality among these patients. Our study aimed to determine the association between the mean and average real variability (ARV) of HbA1c, as well as HbA1c-hemoglobin (HH) ratio with mortality among patients with T2D and CKD.

MATERIALS AND METHODS

We identified 16,868 T2D patients with stage 3 or above CKD from outpatient visits during 2003-2018. We ascertained all-cause and cardiovascular mortality through linkage to Taiwan's National Death Registry. Mortality rates were estimated using the Poisson distribution, and we conducted Cox proportional hazards regressions to assess relative risks of mortality corresponding to the mean HbA1c, ARV of HbA1c and HH ratio.

RESULTS

Compared to patients with a mean HbA1c of 7.0-7.9%, a mean HbA1c < 7.0% was persistently associated with highest risk of all-cause but not cardiovascular mortality after adjusting for confounders. On the contrary, patients with HbA1c-ARV in the second to fourth quartiles and HH ratios in the higher quartiles showed increased risk of all-cause and cardiovascular mortality compared to those in the first quartiles.

CONCLUSIONS

HbA1c-ARV was more effective than mean HbA1c or HH ratio in predicting mortality in T2D patients with CKD. Apart from optimal glucose control, multidisciplinary care focusing on glycemic variability is essential for reducing mortality in these patients.

Current landscape and comprehensive management of glycemic variability in diabetic retinopathy

Diabetic retinopathy (DR), a well-known microvascular complication of diabetes mellitus, remains the main cause of vision loss in working-age adults worldwide. Up to now, there is a shortage of information in the study regarding the contributing factors of DR in diabetes. Accumulating evidence has identified glycemic variability (GV), referred to fluctuations of blood glucose levels, as a risk factor for diabetes-related complications. Recent reports demonstrate that GV plays an important role in accounting for the susceptibility to DR development. However, its exact role in the pathogenesis of DR is still not fully understood. In this review, we highlight the current landscape and relevant mechanisms of GV in DR, as well as address the mechanism-based therapeutic strategies, aiming at better improving the quality of DR management in clinical practice.

Associations between time in range and insulin secretory capacity in Japanese patients with type 2 diabetes

Impaired insulin secretory capacity is associated with high glycemic variability in patients with type 2 diabetes (T2DM). However, there are no existing reports on the association between insulin secretory capacity and time in range (TIR). This retrospective study involved 330 T2DM admitted for diabetes education who underwent intermittently scanned continuous glucose monitoring (isCGM) and had their fasting serum C-peptide immunoreactivity (S-CPR) measured within 5 days of admission. The baseline characteristics were as follows: age, 60.2 years; glycated hemoglobin (HbA1c), 9.2%; S-CPR, 2.2 ng/mL; S-CPR index (S-CPR [ng/mL]/fasting plasma glucose [mg/dL] × 100), 1.6; and TIR, 60.3%. TIR correlated significantly with the S-CPR index, which was confirmed by multivariate analysis that included various factors such as HbA1c. Receiver operating characteristic (ROC) analysis showed that 1.88 was the optimal S-CPR index level to predict TIR ≥ 70%. In addition to HbA1c and biguanide use, the S-CPR index was a significant factor associated with TIR > 70%. S-CPR index values of ≥ 1.88 also correlated significantly with TIR > 70%. In conclusion, insulin secretory capacity is associated with TIR in Japanese T2DM, suggesting that the S-CPR index might be a potentially useful biomarker insulin secretory capacity, in association with TIR.Trial registration UMIN0000254333.

Comparing Equil patch versus traditional catheter insulin pump in type 2 diabetes using continuous glucose monitoring metrics and profiles

AIMS

It is not clear whether there are differences in glycemic control between the Equil patch and the MMT-712 insulin pump. Our objective was to compare two types of insulin pumps in the treatment of type 2 diabetes mellitus (T2DM), using continuous glucose monitoring (CGM) metrics and profiles.

METHODS

This was a randomized case-crossover clinical trial. Participants were hospitalized and randomly allocated to two groups and underwent two types of insulin pump treatments (group A: Equil patch-Medtronic MMT-712 insulin pump; group B: Medtronic MMT-712-Equil patch insulin pump) separated by a 1-day washout period. Glycemic control was achieved after 7-8 days of insulin pump therapy. Each patient received CGM for 5 consecutive days (from day 1 to day 5). On day 3 of CGM performance, the Equil patch insulin pump treatment was switched to Medtronic MMT-712 insulin pump treatment at the same basal and bolus insulin doses or vice versa. CGM metrics and profiles including glycemic variability (GV), time in range (TIR, 3.9-10.0 mmol/L), time below range (TBR, <3.9 mmol/L), time above range (TAR, >10.0 mmol/L), and postprandial glucose excursions, as well as incidence of hypoglycemia.

RESULTS

Forty-six T2DM patients completed the study. There was no significant difference in parameters of daily GV and postprandial glucose excursions between the Equil patch insulin pump treatment and the Medtronic insulin pump treatment. Similarly, there was no between-treatment difference in TIR, TBR, and TAR, as well as the incidence of hypoglycemia.

CONCLUSION

The Equil patch insulin pump was similar to the traditional MMT-712 insulin pump in terms of glycemic control. Equil patch insulin pump is a reliable tool for glycemic management of diabetes mellitus.

Insulin pump treatment vs. multiple daily insulin injections in patients with poorly controlled Type 2 diabetes mellitus: a comparison of cardiovascular effects

AIMS

Both hyperglycaemia and large glycaemic variability are associated with worse outcomes in patients with Type 2 diabetes mellitus (T2DM), possibly causing sympatho-vagal imbalance and endothelial dysfunction. Continuous subcutaneous insulin injection (CSII) improves glycemic control compared to multiple daily insulin injections (MDI). We aimed to assess whether CSII may improve cardiac autonomic and vascular dilation function compared to MDI.

METHODS

We enrolled T2DM patients without cardiovascular disease with poor glycaemic control, despite optimized MDI therapy. Patients were randomized to continue MDI (with multiple daily peripheral glucose measurements) or CSII; insulin dose was adjusted to achieve optimal target ranges of blood glucose levels. Patients were studied at baseline and after 6 months by: 1) flow-mediated dilation (FMD) and nitrate-mediated dilation (NMD) of the brachial artery; 2) heart rate variability (HRV) by 24-hour ECG Holter monitoring (HM). 7-day continuous glucose monitoring (CGM) was performed in 9 and 8 patients of Group 1 and 2, respectively.

RESULTS

Overall, 21 patients were enrolled, 12 randomized to CSII (Group 1) and 9 to MDI (Group 2). The daily dose of insulin and Hb1AC did not differ significantly between the 2 groups, both at baseline and at follow-up. Glucose variability showed some significant improvement at follow-up in the whole population, but no differences were observed between the 2 groups. Both FMD and NMD, as well as HRV parameters, showed no significant differences between the 2 groups at 6-month follow-up.

CONCLUSIONS

In this randomized small study we show that, in T2DM patients, CSII achieves a similar medium-term glycemic control compared to MDI, without any adverse effect on the cardiovascular system.

Persistent epigenetic signals propel a senescence-associated secretory phenotype and trained innate immunity in CD34+ hematopoietic stem cells from diabetic patients

BACKGROUND

Diabetes-induced trained immunity contributes to the development of atherosclerosis and its complications. This study aimed to investigate in humans whether epigenetic signals involved in immune cell activation and inflammation are initiated in hematopoietic stem/progenitor cells (HSPCs) and transferred to differentiated progeny.

METHODS AND RESULTS

High glucose (HG)-exposure of cord blood (CB)-derived HSPCs induced a senescent-associated secretory phenotype (SASP) characterized by cell proliferation lowering, ROS production, telomere shortening, up-regulation of p21 and p27genes, upregulation of NFkB-p65 transcription factor and increased secretion of the inflammatory cytokines TNFα and IL6. Chromatin immunoprecipitation assay (ChIP) of p65 promoter revealed that H3K4me1 histone mark accumulation and methyltransferase SetD7 recruitment, along with the reduction of repressive H3K9me3 histone modification, were involved in NFkB-p65 upregulation of HG-HSPCs, as confirmed by increased RNA polymerase II engagement at gene level. The differentiation of HG-HSPCs into myeloid cells generated highly responsive monocytes, mainly composed of intermediate subsets (CD14hiCD16+), that like the cells from which they derive, were characterized by SASP features and similar epigenetic patterns at the p65 promoter. The clinical relevance of our findings was confirmed in sternal BM-derived HSPCs of T2DM patients. In line with our in vitro model, T2DM HSPCs were characterized by SASP profile and SETD7 upregulation. Additionally, they generated, after myeloid differentiation, senescent monocytes mainly composed of proinflammatory intermediates (CD14hiCD16+) characterized by H3K4me1 accumulation at NFkB-p65 promoter.

CONCLUSIONS

Hyperglycemia induces marked chromatin modifications in HSPCs, which, once transmitted to the cell progeny, contributes to persistent and pathogenic changes in immune cell function and composition.

Hereditary hemochromatosis with homozygous C282Y HFE mutation: possible clinical model to assess effects of elevated reactive oxygen species on the development of cardiovascular disease

Hereditary hemochromatosis with the homozygous C282Y HFE mutation (HH-282H) is a genetic condition which causes iron overload (IO) and elevated reactive oxygen species (ROS) secondary to the IO. Interestingly, even after successful iron removal therapy, HH-282H subjects demonstrate chronically elevated ROS. Raised ROS are also associated with the development of multiple cardiovascular diseases and HH-282H subjects may be at risk to develop these complications. In this narrative review, we consider HH-282H subjects as a clinical model for assessing the contribution of elevated ROS to the development of cardiovascular diseases in subjects with fewer confounding clinical risk factors as compared to other disease conditions with high ROS. We identify HH-282H subjects as a potentially unique clinical model to assess the impact of chronically elevated ROS on the development of cardiovascular disease and to serve as a clinical model to detect effective interventions for anti-ROS therapy.

Glycemic variability: Measurement, target, impact on complications of diabetes and does it really matter?

Over the past two decades, there has been continuous advancement in the accuracy and complexity of continuous glucose monitoring devices. Continuous glucose monitoring provides valuable insights into blood glucose dynamics, and can record glucose fluctuations accurately and completely. Glycemic variability (GV) is a straightforward measure of the extent to which a patient's blood glucose levels fluctuate between high peaks and low nadirs. Many studies have investigated the relationship between GV and complications, primarily in the context of type 2 diabetes. Nevertheless, the exact contribution of GV to the development of diabetes complications remains unclear. In this literature review, we aimed to summarize the existing evidence regarding the measurement, target level, pathophysiological mechanisms relating GV and tissue damage, and population-based studies of GV and diabetes complications. Additionally, we introduce novel methods for measuring GV, and discuss several unresolved issues of GV. In the future, more longitudinal studies and trials are required to confirm the exact role of GV in the development of diabetes complications.

Effects of a Novel Glucokinase Activator, Dorzagliatin, on Glycemic Control and Glucose Fluctuation in Drug-Naïve Patients with Type 2 Diabetes Mellitus

Aim

The prevalence rate of type 2 diabetes mellitus (T2DM) has been increasing and a large proportion of patients still do not achieve adequate or sustainable glycemic control on the basis of previous hypoglycemic treatment. In this present study, we explored whether dorzagliatin, a novel glucokinase activator (GKA), could improve glycemic control and lessen glucose fluctuation in drug-naïve patients with T2DM.

Methods

A self-comparative observational study of 25 drug-naïve patients with T2DM (aged 18-75 years and HbA1c of 7.5%-11.0%) treated with dorzagliatin 75 mg twice daily for 52 weeks. Before and after dorzagliatin intervention, the serum levels of hemoglobin A1c (HbA1c), insulin, and C-peptide were measured repeatedly during fasting and after a mixed meal. The continuous glucose monitoring (CGM) device was also used to obtain 24-hour glucose profiles and assess the changes in glycemic variability parameters.

Results

After 52 weeks of treatment with dorzagliatin, a numerally greater reduction in HbA1c of 1.03% from the baseline was observed in patients with T2DM, accompanied by significant improvement in insulin resistance and insulin secretion. Moreover, the standard deviation of blood glucose (SDBG) and the mean amplitude of glycemic excursion (MAGE) derived from CGM data were significantly decreased after dorzagliatin therapy. The 24-h glucose variation profile showed that study patients had obviously lower mean glucose levels during the postprandial period from the baseline to week 52, an effect also demonstrated by the significant decrease in the incremental area under glucose concentration versus time curve for 2 h (iAUC0-2 h) after meals.

Conclusions

This study suggests that dorzagliatin therapy could effectively improve glycemic control and glucose fluctuation in drug-naïve patients with T2DM.

Glycemic variability leads to higher levels of auto-oxidized oxysterol species in patients with type 1 diabetes mellitus

PURPOSE

Hyperglycemia and glycemic variability (GV) are associated with oxidative stress in patients with diabetes mellitus (DM). Oxysterol species, produced by the non-enzymatic oxidation of cholesterol, are potential biomarkers of oxidative stress. This study examined the relationship between auto-oxidized oxysterols and GV in patients with type 1 DM.

METHODS

Thirty patients with type 1 DM using a continuous subcutaneous insulin infusion pump therapy and a healthy control group (n = 30) were included in this prospective study. A Continuous Glucose Monitoring System device was applied for 72 h. Blood samples were taken for oxysterols produced by non-enzymatic oxidation [7-ketocholesterol (7-KC) and cholestane-3β, 5α, 6β-triol (Chol-Triol)] levels at 72 h. Short-term glycemic variability parameters, mean amplitude of glycemic excursions (MAGE), the standard deviation of glucose measurements (Glucose-SD), and mean of daily differences (MODD) were calculated with continuous glucose monitoring data. HbA1c was used to evaluate glycemic control and HbA1c-SD (the SD of HbA1c over the past year) for long-term glycemic variability.

RESULTS

7-KC and Chol-triol levels were significantly higher in the study group than in the control group. Strong positive correlations were found between 7-KC with MAGE(24-48 h) and Glucose-SD(24-48 h). 7-KC was positively correlated with MAGE(0-72 h) and Glucose-SD(0-72 h). No significant correlation was found between HbA1c and HbA1c -SD with oxysterol levels. The regression models showed that SD(24-48 h) and MAGE(24-48 h) predicted 7-KC levels while HbA1c did not.

CONCLUSIONS

Glycemic variability leads to higher levels of auto-oxidized oxysterol species in patients with type 1 DM independent of long-term glycemic control.

Trimethylamine N-oxide predicts stroke severity in diabetic patients with acute ischaemic stroke and is related to glycemic variability

BACKGROUND AND PURPOSE

The present study analyzed the relationship between circulating trimethylamine N-oxide (TMAO) levels and stroke severity in diabetic patients with acute ischaemic stroke. A further aim was to investigate whether higher TMAO levels were associated with platelet aggregation and glycemic variability.

METHODS

This was a cross-sectional analysis of 108 patients with type 2 diabetes mellitus (DM) undergoing acute ischaemic stroke and 60 healthy controls. Fasting plasma TMAO was measured using high-performance liquid chromatography with online electrospray ionization tandem mass spectrometry.

RESULTS

Plasma TMAO levels of patients with acute ischaemic stroke were significantly higher than those of healthy controls. Amongst stroke patients, 50 were defined as undergoing mild stroke, and their plasma TMAO levels were lower compared to those with moderate to severe stroke. Platelet aggregation and mean amplitude of glycemic excursions were both correlated with plasma TMAO levels and these relationships remained significant in multiple linear regression analyses. Moreover, in streptozotocin-induced diabetic rats fed a diet enriched with choline to increase TMAO synthesis, platelet aggregation was significantly increased in the DM + choline and fluctuating DM (FDM) + choline groups compared to the control group. This increase was abolished in rats receiving oral antibiotics, which markedly reduced plasma TMAO levels. Importantly, compared with the DM + choline group, the FDM + choline group displayed significantly elevated TMAO levels and higher platelet aggregation.

CONCLUSIONS

Our results demonstrated that higher plasma TMAO levels were associated with stroke severity and suggested a novel link between plasma TMAO levels and glycemic variability in diabetic patients with acute ischaemic stroke.

Adiponectin: A "Friendly adipokine" in Diabetic Retinopathy?

PURPOSE

Adiponectin has also been associated with diabetic retinopathy, a diabetic microvascular complication. However, the mechanism of action of adiponectin in retinopathy is still under investigation. This review summarizes emerging evidence on the association with diabetic retinopathy in type 2 diabetes.

METHODS

We reviwed papers from 2004 to 2022 and included studies related to retinopathy and its association with blood and intraocular adiponectin in type 2 diabetes.

RESULTS

Most of the studies analyzed in this review suggested an association between the diabetic retinopathy progression and intraocular, serum, or plasma adiponectin levels. Increased levels of adiponectin contributed to the development of the disease in diabetic patients. In a minority of studies, it was indicated an inversely proportional relationship between adiponectin concentration and diabetic retinopathy severity.

CONCLUSION

The high levels of adiponectin in diabetic patients may be related to the decrease in renal clearance. Under this situation, if the predominant isoform is globular adiponectin, this may explain the retinopathy progression, considering a pro-inflammatory response induced by this isoform. However, the actions of adiponectin in diabetic retinopathy pathophysiology are still controversial.

Postprandial Hyperlipidemia: Its Pathophysiology, Diagnosis, Atherogenesis, and Treatments

Postprandial hyperlipidemia showing postprandial increases in serum triglyceride (TG) is associated with the development of atherosclerotic cardiovascular disease (ASCVD). To diagnose postprandial hyperlipidemia, the oral fat loading test (OFLT) should be performed; however, this test is very time-consuming and is difficult to perform. Elevated serum TG levels reflect an increase in TG-rich lipoproteins (TRLs), such as chylomicrons (CM), very low-density lipoproteins (VLDL), and their remnants (CM remnants [CMRs] and VLDL remnants [VLDLRs]). Understanding of elevation in CMR and/or VLDLR can lead us to understand the existence of postprandial hyperlipidemia. The measurement of apo B48, which is a constituent of CM and CMR; non-fasting TG, which includes TG content in all lipoproteins including CM and CMR; non-high-density lipoprotein cholesterol (non-HDL-C), which includes TRLs and low-density lipoprotein; and remnant cholesterol are useful to reveal the existence of postprandial hyperlipidemia. Postprandial hyperlipidemia is observed in patients with familial type III hyperlipoproteinemia, familial combined hyperlipidemia, chronic kidney disease, metabolic syndrome and type 2 diabetes. Postprandial hyperlipidemia is closely related to postprandial hyperglycemia, and insulin resistance may be an inducing and enhancing factor for both postprandial hyperlipidemia and postprandial hyperglycemia. Remnant lipoproteins and metabolic disorders associated with postprandial hyperlipidemia have various atherogenic properties such as induction of inflammation and endothelial dysfunction. A healthy diet, calorie restriction, weight loss, and exercise positively impact postprandial hyperlipidemia. Anti-hyperlipidemic drugs such pemafibrate, fenofibrate, bezafibrate, ezetimibe, and eicosapentaenoic acid have been shown to improve postprandial hyperlipidemia. Anti-diabetic drugs including metformin, alpha-glucosidase inhibitors, pioglitazone, dipeptidyl-peptidase-4 inhibitors and glucagon-like peptide 1 analogues have been shown to ameliorate postprandial hyperlipidemia. Although sodium glucose cotransporter-2 inhibitors have not been proven to reduce postprandial hyperlipidemia, they reduced fasting apo B48 and remnant lipoprotein cholesterol. In conclusion, it is important to appropriately understand the existence of postprandial hyperlipidemia and to connect it to optimal treatments. However, there are some problems with the diagnosis for postprandial hyperlipidemia. Postprandial hyperlipidemia cannot be specifically defined by measures such as TG levels 2 h after a meal. To study interventions for postprandial hyperlipidemia with the outcome of preventing the onset of ASCVD, it is necessary to define postprandial hyperlipidemia using reference values such as IGT.

Role of Epigenetics and Metabolomics in Predicting Endothelial Dysfunction in Type 2 Diabetes

Type 2 diabetes (T2D) is a worldwide health problem and cardiovascular disease (CVD) is a leading cause of morbidity and mortality in T2D patients, making the prevention of CVD onset a major priority. It is therefore crucial to optimize diagnosis and treatment to reduce this burden. Endothelial dysfunction is one of the most important prognostic factors for CVD progression, thus novel approaches to identify the early phase of endothelial dysfunction may lead to specific preventive measures to reduce the occurrence of CVD. Nowadays, multiomics approaches have provided unprecedented opportunities to stratify T2D patients into endotypes, improve therapeutic treatment and outcome and amend the survival prediction. Among omics strategies, epigenetics and metabolomics are gaining increasing interest. Recently, a dynamic correlation between metabolic pathways and gene expression through chromatin remodeling, such as DNA methylation, has emerged, indicating new perspectives on the regulatory networks impacting cellular processes. Thus, a better understanding of epigenetic-metabolite relationships can provide insight into the physiological processes altered early in the endothelium that ultimately head to disease development. Here, recent studies on epigenetics and metabolomics related to CVD prevention potentially useful to identify disease biomarkers, as well as new therapies hopefully targeting the early phase of endothelial dysfunction are highlighted.

The Value of the Apolipoprotein B/Apolipoprotein A1 Ratio in Predicting the Rapid Progression of Non-Culprit Coronary Lesions in Acute Coronary Syndrome in Patients with Diabetes Mellitus after Percutaneous Coronary Intervention

This study aims to assess the predictive value of the apolipoprotein B (ApoB) /apolipoprotein A1 (ApoA1) ratio in acute coronary syndrome (ACS) in patients with diabetes mellitus (DM) for the rapid progression (RP) of non-culprit coronary lesions (NCCLs) after percutaneous coronary intervention (PCI) and observe the effect of the ApoB/ApoA1 ratio on major adverse cardiac events (MACE).A total of 175 patients with DM presenting with ACS who received a PCI and an average 13-month follow-up coronary angiography (CAG) were enrolled from January 2015 to December 2020. According to the CAG, the patients were divided into the RP group and the non-RP group. MACE was defined as a composite of death from cardiac causes, cardiac arrest, myocardial infarction, or rehospitalization from unstable or progressive angina at the end of a 24-month follow-up.The low-density lipoprotein cholesterol (LDL-C), ApoB, ApoB/ApoA1 ratio, and LDL-C/high-density lipoprotein cholesterol (HDL-C) ratio levels at baseline were significantly higher in the RP group than in the non-RP group. The ApoA1 level at baseline in the non-RP group was significantly higher than in the RP group. The predictive significance of the ApoB/ApoA1 ratio (area under the curve (AUC) = 0.712) for the RP of NCCLs was significantly higher than those of ApoA1, ApoB, LDL-C/HDL-C ratio (AUC = 0.628, AUC = 0.640, and AUC = 0.620, respectively). A higher ApoB/ApoA1 ratio and the RP of NCCLs were significantly associated with the occurrence of MACE.The ApoB/ApoA1 ratio was an effective clinical indicator for the RP of NCCLs after PCI in patients with DM presenting with ACS. The high ApoB/ApoA1 ratio and the RP of NCCLs were two risks for MACE.

Higher metabolic variability increases the risk of depressive disorder in type 2 diabetes mellitus: a longitudinal nationwide cohort study

BACKGROUND AND OBJECTIVES

While variabilities in metabolic parameters (METv) have been linked to adverse health outcomes in type 2 DM, their association with depression is yet to be studied. This research aimed to investigate the association between METv and depressive disorder in patients with type 2 DM.

METHODS

The study involved a nationwide cohort of 1,119,631 type 2 DM patients who had undergone three or more serial health examinations between 2005 and 2012. At each visit, body mass index (BMI), fasting glucose (FG), systolic blood pressure (BP), and total cholesterol (TC) were measured and stratified into quartiles, with Q4 being the highest and Q1 the lowest. The risk of depressive disorder was evaluated using Cox proportional hazard regression models, which accounted for METs in the indexes, after adjusting for sex, income status, lifestyle habits, medical comorbidities, DM severity, and baseline levels of BMI, FG, BP, and TC.

RESULTS

During a mean follow-up period of 6.00 ± 2.42 years, 239,477 (21.4%) cases of type 2 DM patients developed depressive disorder. The risk of developing depressive disorder was gradually increased as the number of METv increased (HR 1.18; 95% CI 1.13, 1.23 for the group with the highest METv in all parameters compared to those with the lowest METv in all parameters). In the subgroup analysis, the risk of developing depressive disorder was 43% higher in men (HR 1.43; 95% CI 1.34, 1.51), and 31% higher in those younger than 65 years of age (HR 1.31; 95% CI 1.23, 1.39) in the group with the highest number of METv compared to the group with the lowest number of METv.

CONCLUSION

In type 2 DM, higher METv was an independent risk factor for depressive disorder. This risk is notably elevated in men and individuals under the age of 65 years.

Intensified glycemic control by HbA1c for patients with coronary heart disease and Type 2 diabetes: a review of findings and conclusions

The occurrence and development of coronary heart disease (CHD) are closely linked to fluctuations in blood glucose levels. While the efficacy of intensified treatment guided by HbA1c levels remains uncertain for individuals with diabetes and CHD, this review summarizes the findings and conclusions regarding HbA1c in the context of CHD. Our review showed a curvilinear correlation between regulated level of HbA1c and therapeutic effectiveness of intensified glycemic control among patients with type 2 diabetes and coronary heart disease. It is necessary to optimize the dynamic monitoring indicators of HbA1c, combine genetic profiles, haptoglobin phenotypes for example and select more suitable hypoglycemic drugs to establish more appropriate glucose-controlling guideline for patients with CHD at different stage of diabetes.

Methylglyoxal-Modified Albumin Effects on Endothelial Arginase Enzyme and Vascular Function

Advanced glycation end products (AGEs) contribute significantly to vascular dysfunction (VD) in diabetes. Decreased nitric oxide (NO) is a hallmark in VD. In endothelial cells, NO is produced by endothelial NO synthase (eNOS) from L-arginine. Arginase competes with NOS for L-arginine to produce urea and ornithine, limiting NO production. Arginase upregulation was reported in hyperglycemia; however, AGEs' role in arginase regulation is unknown. Here, we investigated the effects of methylglyoxal-modified albumin (MGA) on arginase activity and protein expression in mouse aortic endothelial cells (MAEC) and on vascular function in mice aortas. Exposure of MAEC to MGA increased arginase activity, which was abrogated by MEK/ERK1/2 inhibitor, p38 MAPK inhibitor, and ABH (arginase inhibitor). Immunodetection of arginase revealed MGA-induced protein expression for arginase I. In aortic rings, MGA pretreatment impaired acetylcholine (ACh)-induced vasorelaxation, which was reversed by ABH. Intracellular NO detection by DAF-2DA revealed blunted ACh-induced NO production with MGA treatment that was reversed by ABH. In conclusion, AGEs increase arginase activity probably through the ERK1/2/p38 MAPK pathway due to increased arginase I expression. Furthermore, AGEs impair vascular function that can be reversed by arginase inhibition. Therefore, AGEs may be pivotal in arginase deleterious effects in diabetic VD, providing a novel therapeutic target.

Triglyceride-glucose index level and variability and outcomes in patients with acute coronary syndrome undergoing percutaneous coronary intervention: an observational cohort study

BACKGROUND

The associations between the long-term triglyceride-glucose (TyG) index level and variability and clinical outcomes in patients with acute coronary syndrome (ACS) undergoing percutaneous coronary intervention (PCI) have not been well studied.

METHODS

A total of 1,694 ACS patients with at least three postbaseline TyG index measurements within 2 years after PCI were included in the present study. The TyG index was defined as ln (fasting triglycerides [mg/dL] × fasting plasma glucose [mg/dL]/2). Multivariable-adjusted Cox proportional hazard models were used to examine the association between baseline and mean TyG index levels and TyG index variability and the risk of major adverse cardiovascular and cerebrovascular events (MACCEs).

RESULTS

During the median follow-up of 31 months, the overall incidence of MACCE was 5.9%. Both high baseline and mean TyG index levels were independently associated with an increased risk of MACCEs after adjustment for multiple potential confounders (hazard ratio [HR) 1.76 95% confidence interval [CI] 1.06-2.93; and HR 2.73 95% CI 1.57-4.74). Similarly, higher TyG index variability by successive variation (SD) was well related to a higher prevalence of MACCEs (HR 2.17 95% CI 1.28-3.68). In addition, the mean TyG index level showed a stronger risk prediction for MACCEs than the baseline TyG index level and TyG index-SD (AUCs 0.618 vs 0.566 vs 0.566).

CONCLUSIONS

The risk of MACCEs significantly increased with higher baseline and mean TyG index levels, as well as TyG index variability, in patients with ACS undergoing PCI. In particular, the mean TyG index level exhibited the highest predicting ability for MACCEs. Therefore, monitoring the long-term pattern of the TyG index deserves attention in clinical practice.

Association of visit-to-visit HbA1c variability with cardiovascular diseases in type 2 diabetes within or outside the target range of HbA1c

Background

Although a growing attention has been recently paid to the role of HbA1c variability in the risk of diabetic complications, the impact of HbA1c variability on cardiovascular diseases (CVD) in type 2 diabetes is still debated. The aim of the study is to investigate the association of HbA1c variability with CVD in individuals within or outside the target range of HbA1c.

Methods

Using data from Action in Diabetes and Vascular disease: preterAx and diamicroN-MR Controlled Evaluation (ADVANCE), we enrolled 855 patients with type 2 diabetes in China. The primary outcomes included major macrovascular events and major microvascular events. Visit-to-visit HbA1c variability was expressed as the coefficient of variation (CV) of five measurements of HbA1c taken 3-24 months after treatment. Cox proportional hazard models were used to estimate adjusted hazard ratios (aHR).

Results

Among 855 patients in the intensive glucose treatment group, 563 and 292 patients were assigned to the group of "within the target range of HbA1c" (WTH) (updated mean HbA1c ≤ 7.0%) and "outside the target range of HbA1c" (OTH) (updated mean HbA1c > 7.0%), respectively. HbA1c variability was positively associated with the risk of major microvascular events in all patients and both the subgroups during a median follow-up period of 4.8 years. Particularly, the risk related to HbA1c variability was higher in patients in WTH group for the new or worsening nephropathy [aHR: 3.35; 95% confidence interval (CI): 1.05-10.74; P = 0.042].

Conclusions

This retrospective cohort study confirmed the positive correlation between HbA1c variability and major microvascular events, especially in subjects in WTH or OTH.

Glycaemic variability and progression of chronic kidney disease in people with diabetes and comorbid kidney disease: Retrospective cohort study

AIM

To investigate the association between glycaemic variability and the development of End-Stage-Kidney-Disease (ESKD) among individuals with diabetes and chronic kidney disease.

METHODS

A cohort study using UK electronic primary care health records from the Clinical Practice Research Datalink. Glycaemic variability was assessed using a variability score and intra-individual coefficient of variation (CV) of HbA1c. We calculated sub-distribution hazard ratios (sHR) for developing ESKD using competing risk regression analysis.

RESULTS

There were 37,222 eligible participants (45.5 % male), with a mean age of 76.4 years (SD ± 9.2), and a mean baseline eGFR 40.7 (±10.7) ml/min/1.73 m². There were 5,086 incidents of ESKD in the follow-up period. The adjusted sHR (95 %CI) for each variability score group, were as follows: 21-40, 1.38 (1.27-1.50); 41-60, 1.54 (1.41-1.68); 61-80, 1.61 (1.45-1.79); and 81-100, 1.42 (1.19-1.68), compared with the group (score 0-20) with least variability. The adjusted sHR for CV were as follows: 6.7-9.9, 1.29 (1.15-1.45); 10.0-13.9, 1.55 (1.39-1.74); 14.0-20.1, 1.79 (1.60-2.01) and ≥20.2, 2.10 (1.88-2.34) compared to reference group 0-6.6.

CONCLUSIONS

Glycaemic variability was strongly associated with the development of ESKD in people with diabetes and CKD.

Targeting SIRT1 Rescues Age- and Obesity-Induced Microvascular Dysfunction in Ex Vivo Human Vessels

BACKGROUND

Experimental evidence suggests a key role of SIRT1 (silent information regulator 1) in age- and metabolic-related vascular dysfunction. Whether these effects hold true in the human microvasculature is unknown. We aimed to investigate the SIRT1 role in very early stages of age- and obesity-related microvascular dysfunction in humans.

METHODS

Ninety-five subjects undergoing elective laparoscopic surgery were recruited and stratified based on their body mass index status (above or below 30 kg/m²) and age (above or below 40 years) in 4 groups: Young Nonobese, Young Obese, Old Nonobese, and Old Obese. We measured small resistance arteries' endothelial function by pressurized micromyography before and after incubation with a SIRT1 agonist (SRT1720) and a mitochondria reactive oxygen species (mtROS) scavenger (MitoTEMPO). We assessed vascular levels of mtROS and nitric oxide availability by confocal microscopy and vascular gene expression of SIRT1 and mitochondrial proteins by qPCR. Chromatin immunoprecipitation assay was employed to investigate SIRT1-dependent epigenetic regulation of mitochondrial proteins.

RESULTS

Compared with Young Nonobese, obese and older patients showed lower vascular expression of SIRT1 and antioxidant proteins (FOXO3 [forkhead box protein O3] and SOD2) and higher expression of pro-oxidant and aging mitochondria proteins p66^Shc and Arginase II. Old Obese, Young Obese and Old Nonobese groups endothelial dysfunction was rescued by SRT1720. The restoration was comparable to the one obtained with mitoTEMPO. These effects were explained by SIRT1-dependent chromatin changes leading to reduced p66^Shc expression and upregulation of proteins involved in mitochondria respiratory chain.

CONCLUSIONS

SIRT1 is a novel central modulator of the earliest microvascular damage induced by age and obesity. Through a complex epigenetic control mainly involving p66^Shc and Arginase II, it influences mtROS levels, NO availability, and the expression of proteins of the mitochondria respiratory chain. Therapeutic modulation of SIRT1 restores obesity- and age-related endothelial dysfunction. Early targeting of SIRT1 might represent a crucial strategy to prevent age- and obesity-related microvascular dysfunction.

Patient-Tailored Decision Support System Improves Short- and Long-Term Glycemic Control in Type 2 Diabetes

BACKGROUND

The increasing prevalence of type 2 diabetes mellitus (T2D) and specialist shortage has caused a healthcare gap that can be bridged by a decision support system (DSS). We investigated whether a diabetes DSS can improve long- and/or short-term glycemic control.

METHODS

This is a retrospective observational cohort study of the Diabetiva program, which offered a patient-tailored DSS using Karlsburger Diabetes-Management System (KADIS) once a year. Glycemic control was analyzed at baseline and after 12 months in 452 individuals with T2D. Time in range (TIR; glucose 3.9-10 mmol/L) and Q-Score, a composite metric developed for analysis of continuous glucose profiles, were short-term and HbA1c long-term measures of glycemic control. Glucose variability (GV) was also measured.

RESULTS

At baseline, one-third of patients had good short- and long-term glycemic control. Q-Score identified insufficient short-term glycemic control in 17.9% of patients with HbA1c <6.5%, mainly due to hypoglycemia. GV and hyperglycemia were responsible in patients with HbA1c >7.5% and >8%, respectively. Application of DSS at baseline improved short- and long-term glycemic control, as shown by the reduced Q-Score, GV, and HbA1c after 12 months. Multiple regression demonstrated that the total effect on GV resulted from the single effects of all influential parameters.

CONCLUSIONS

DSS can improve short- and long-term glycemic control in individuals with T2D without increasing hypoglycemia. The Q-Score allows identification of individuals with insufficient glycemic control. An effective strategy for therapy optimization could be the selection of individuals with T2D most at need using the Q-Score, followed by offering patient-tailored DSS.

Epigenetic modifications in metabolic memory: What are the memories, and can we erase them?

Inherent and acquired abnormalities in gene regulation due to the influence of genetics and epigenetics (traits related to environment rather than genetic factors) underlie many diseases including diabetes. Diabetes could lead to multiple complications including retinopathy, nephropathy, and cardiovascular disease that greatly increase morbidity and mortality. Epigenetic changes have also been linked to diabetes-related complications. Genes associated with many pathophysiological features of these vascular complications (e.g., inflammation, fibrosis, and oxidative stress) can be regulated by epigenetic mechanisms involving histone posttranslational modifications, DNA methylation, changes in chromatin structure/remodeling, and noncoding RNAs. Intriguingly, these epigenetic changes triggered during early periods of hyperglycemic exposure and uncontrolled diabetes are not immediately corrected even after restoration of normoglycemia and metabolic balance. This latency in effect across time and conditions is associated with persistent development of complications in diabetes with prior history of poor glycemic control, termed as metabolic memory or legacy effect. Epigenetic modifications are generally reversible and provide a window of therapeutic opportunity to ameliorate cellular dysfunction and mitigate or "erase" metabolic memory. Notably, trained immunity and related epigenetic changes transmitted from hematopoietic stem cells to innate immune cells have also been implicated in metabolic memory. Hence, identification of epigenetic variations at candidate genes, or epigenetic signatures genome-wide by epigenome-wide association studies can aid in prompt diagnosis to prevent progression of complications and identification of much-needed new therapeutic targets. Herein, we provide a review of epigenetics and epigenomics in metabolic memory of diabetic complications covering the current basic research, clinical data, and translational implications.

Association between RAC1 gene variation, redox homeostasis and type 2 diabetes mellitus

BACKGROUND

Increased production of reactive oxygen species (ROS) and oxidative stress are known to play a key role in the pathogenesis of type 2 diabetes (T2D); however, the relationship between genes encoding a multi-subunit ROS-generated enzyme NADPH oxidase and disease susceptibility remains unexplored.

AIMS

The present pilot study investigated whether single-nucleotide polymorphisms (SNP) at the RAC1 gene (Rac family small GTPase 1), a molecular switcher of NADPH oxidase, are associated with the risk of T2D, glucose metabolism and redox homeostasis.

MATERIALS & METHODS

DNA samples from 3206 unrelated Russian subjects (1579 T2D patients and 1627 controls) were genotyped for six common SNPs rs4724800, rs7784465, rs10951982, rs10238136, rs836478 and rs9374 of RAC1 using the MassArray-4 system.

RESULTS

SNP rs7784465 was associated with an increased risk of T2D (p = .0003), and significant differences in the RAC1 haplotypes occurred between the cases and controls (p = .005). Seventeen combinations of RAC1 genotypes showed significant associations with T2D risk (FDR <0.05). Associations of RAC1 polymorphisms with T2D were modified by environmental factors such as sedentary lifestyle, psychological stresses, a dietary deficit of fresh fruits/vegetables and increased carbohydrate intake. RAC1 polymorphisms were associated with biochemical parameters in diabetics: rs7784465 (p = .015) and rs836478 (p = .028) with increased glycated haemoglobin, rs836478 (p = .005) with increased fasting blood glucose, oxidized glutathione (p = .012) and uric acid (p = .034). Haplotype rs4724800A-rs7784465C-rs10951982G-rs10238136A-rs836478C-rs9374G was strongly associated with increased levels of hydrogen peroxide (p < .0001).

CONCLUSION

Thus, polymorphisms in the RAC1 gene represent novel genetic markers of type 2 diabetes, and their link with glucose metabolism and disease pathogenesis is associated with the changes in redox homeostasis.

The Level of HbA1c Evaluates the Extent of Coronary Atherosclerosis Lesions and the Prognosis in Diabetes with Acute Coronary Syndrome

Background

The level of HbA1c can reflect the average level of blood glucose over 3 months, which is the gold standard indicator for monitoring blood glucose. The relationship between the level of HbA1c and the extent of coronary atherosclerosis lesions or the prognosis in diabetes with acute coronary syndrome (ACS) remains poorly understood.

Aims

To explore whether the level of HbA1c can evaluate the extent of coronary atherosclerosis lesions or the prognosis in diabetes with acute coronary syndrome (ACS) using the SYNTAX score, the Global Registry of Acute Coronary Events (GRACE) score, left ventricular function (LVEF), left ventricular end-diastolic volume (LVEDV), and major adverse cardiac events (MACEs) in the hospital and 12 months after discharge.

Methods

This study was a prospective, randomized, open-label, and parallel group study. Patients with diabetes with ACS were recruited into this study indiscriminately, and all the participants were divided into two groups according to the level of HbA1c: HbA1c level ≤ 7%group and HbA1c level > 7%group. The followings were used as the evaluation indicators: SYNTAX score, GRACE score, LVEF, LVEDV, and MACEs in hospital and 12 months after discharge.

Results

A total of 233 patients with diabetes and ACS were enrolled and assigned to two groups according to their level of HbA1c: the HbA1c ≤ 7%group (n = 92) and the HbA1c > 7%group (n = 141). The results showed that the proportion of STEMI was higher in the HbA1c ≤7% group (p < 0.05), while the proportion of NSTEMI has not significantly higher in the HbA1c >7% group (p > 0.05). Regression analysis indicated that HbA1c level was significantly positively correlated with GRACE score (r = 0.156, F = 5.784, p = 0.017, n = 233) and SYNTAX score (r = 0.237, F = 13.788, p < 0.001, n = 233), and there were no statistically significant differences in LVEDV and LVEF between the two groups (p > 0.05). The total MACEs rate showed no significant difference between the two groups during hospitalization (p > 0.05) but showed significant differences at 12 months after discharge (p < 0.05).

Conclusions

This study shows that HbA1c level was positively correlated with the extent of coronary atherosclerosis lesions and the prognosis in diabetes with ACS. The higher the HbA1c level is, the more severe the coronary atherosclerotic lesion and the worse the prognosis in diabetes with ACS are.

Studying Epigenetics of Cardiovascular Diseases on Chip Guide

Epigenetics is defined as the study of inheritable changes in the gene expressions and phenotypes that occurs without altering the normal DNA sequence. These changes are mainly due to an alteration in chromatin or its packaging, which changes the DNA accessibility. DNA methylation, histone modification, and noncoding or microRNAs can best explain the mechanism of epigenetics. There are various DNA methylated enzymes, histone-modifying enzymes, and microRNAs involved in the cause of various CVDs (cardiovascular diseases) such as cardiac hypertrophy, heart failure, and hypertension. Moreover, various CVD risk factors such as diabetes mellitus, hypoxia, aging, dyslipidemia, and their epigenetics are also discussed together with CVDs such as CHD (coronary heart disease) and PAH (pulmonary arterial hypertension). Furthermore, different techniques involved in epigenetic chromatin mapping are explained. Among these techniques, the ChIP-on-chip guide is explained with regard to its role in cardiac hypertrophy, a final form of heart failure. This review focuses on different epigenetic factors that are involved in causing cardiovascular diseases.

Time in Range Does Not Associate With Carotid Artery Wall Thickness and Endothelial Function in Type 1 Diabetes

BACKGROUND

Patients with Type 1 diabetes (T1D) have an increased risk of developing atherosclerosis and complications as myocardial infarction and peripheral artery disease. The thickening of the carotid wall and the brachial artery dysfunction are early and preclinical manifestations of atherosclerosis. The standard marker of care for assessment of glycemic control, glycated hemoglobin, does not associate with early atherosclerosis. We have hypothesized that the emerging metric of glycemic control, as the time spent in the target range (TIR), might be associated with carotid thickening and endothelial dysfunction. According to the hypothesis, we have designed the present research with the aim to evaluate the association between TIR collected in the short and long term and the measures of arterial morphology and function in patients with T1D.

METHODS

In our study, 70 patients and 35 healthy controls underwent ultrasound vascular study to measure carotid artery intima-media thickness (IMT) and brachial artery endothelial function by the flow-mediated dilation (FMD) technique. TIR was collected by a continuous glucose monitoring system for 2 weeks, 3 months, and 6 months before the vascular study.

RESULTS

Patients with T1D showed a significantly higher carotid IMT (mean±SE, 644±19 vs. 568±29 µ; p= 0.04) and a significantly lower FMD (mean±SE, 7.6±0.4 vs. 9.8±0.6%; p=0.01) compared with control subjects. No significant relationship between IMT, FMD, and TIR collected in the short and long term emerged.

CONCLUSIONS

Young patients with T1D have early vascular abnormalities. The percent of TIR does not correlate with preclinical atherosclerosis. This finding underlines the complexity of the interplay between diabetes and atherosclerosis.

Impact of short-term glycemic variability on risk of all-cause mortality in type 2 diabetes patients with well-controlled glucose profile by continuous glucose monitoring: A prospective cohort study

AIMS

To investigate the association between short-term glycemic variability (GV) and all-cause mortality in type 2 diabetes with well-controlled glucose profile by continuous glucose monitoring (CGM).

METHODS

In this prospective study, 1839 diabetes patients who reached percentage of time in the target glucose range of 3.9-10 mmol/L > 70%, percentage of time above range of 10 mmol/L < 25% and percentage of time below range of 3.9 mmol/L < 4% on CGM were enrolled and were classified into five groups by coefficient of variation for glucose (%CV) level: ≤20%, 20-25%, 25-30%, 30-35%, and > 35%. Cox proportional hazard models were used to estimate hazard ratios (HRs) of all-cause mortality risk associated with the different %CV categories.

RESULTS

At baseline, participants had mean age of 60.9 years and mean HbA_1c of 7.3% (56 mmol/mol). A total of 165 deaths were identified during a median follow-up of 6.9 years. In multivariate Cox regression analysis, HRs associated with %CV categories were 1.00, 1.16 (95% CI 0.78-1.73), 1.38 (95% CI 0.89-2.15), 1.33 (95% CI 0.77-2.29) and 2.26 (95% CI 1.13-4.52) for all-cause mortality.

CONCLUSIONS

Greater %CV was associated with increased risk for all-cause mortality even among patients with seemingly well-controlled glucose status.

Scoring model to predict risk of chronic kidney disease in Chinese health screening examinees with type 2 diabetes

PURPOSE

As health screening continues to increase in China, there is an opportunity to integrate a large number of demographic as well as subjective and objective clinical data into risk prediction modeling. The aim of this study was to develop and validate a prediction model for chronic kidney disease (CKD) in Chinese health screening examinees with type 2 diabetes mellitus (T2DM).

METHODS

We conducted a retrospective cohort study consisting of 2051 Chinese T2DM patients between 35 and 78 years old who were enrolled in the XY3CKD Follow-up Program between 2009 and 2010. All participants were randomly assigned into a derivation set or a validation set at a 2:1 ratio. Cox proportional hazards regression model was selected for the analysis of risk factors for the development of the proposed risk model of CKD. We established a prediction model with a scoring system following the steps proposed by the Framingham Heart Study.

RESULTS

The mean follow-up was 8.52 years, with a total of 315 (23.20%) and 189 (27.27%) incident CKD cases in the derivation set and validation set, respectively. We identified the following risk factors: age, gender, body mass index, duration of type 2 diabetes, variation of fasting blood glucose, stroke, and hypertension. The points were summed to obtain individual scores (from 0 to 15). The areas under the curve of 3-, 5- and 10-year CKD risks were 0.843, 0.799 and 0.780 in the derivation set and 0.871, 0.803 and 0.785 in the validation set, respectively.

CONCLUSIONS

The proposed scoring system is a promising tool for further application of assisting Chinese medical staff for early prevention of T2DM complications among health screening examinees.

Mechanisms and clinical implications of endothelium-dependent vasomotor dysfunction in coronary microvasculature

Coronary microvascular disease (CMD), which affects the arterioles and capillary endothelium that regulate myocardial perfusion, is an increasingly recognized source of morbidity and mortality, particularly in the setting of metabolic syndrome. The coronary endothelium plays a pivotal role in maintaining homeostasis, though factors such as diabetes, hypertension, hyperlipidemia, and obesity can contribute to endothelial injury and consequently arteriolar vasomotor dysfunction. These disturbances in the coronary microvasculature clinically manifest as diminished coronary flow reserve, which is a known independent risk factor for cardiac death, even in the absence of macrovascular atherosclerotic disease. Therefore, a growing body of literature has examined the molecular mechanisms by which coronary microvascular injury occurs at the level of the endothelium and the consequences on arteriolar vasomotor responses. This review will begin with an overview of normal coronary microvascular physiology, modalities of measuring coronary microvascular function, and clinical implications of CMD. These introductory topics will be followed by a discussion of recent advances in the understanding of the mechanisms by which inflammation, oxidative stress, insulin resistance, hyperlipidemia, hypertension, shear stress, endothelial cell senescence, and tissue ischemia dysregulate coronary endothelial homeostasis and arteriolar vasomotor function.

Glycaemic Variability and Hyperglycaemia as Prognostic Markers of Major Cardiovascular Events in Diabetic Patients Hospitalised in Cardiology Intensive Care Unit for Acute Heart Failure

(1) Background: Hyperglycaemia and hypoglycaemia are both emerging risk factors for cardiovascular disease. Nevertheless, the potential effect of glycaemic variability (GV) on mid-term major cardiovascular events (MACE) in diabetic patients presenting with acute heart failure (AHF) remains unclear. This study investigates the prognostic value of GV in diabetic patients presenting with acute heart failure (AHF). (2) Methods: this was an observational study including consecutive patients with diabetes and AHF between January 2015 and November 2016. GV was calculated using standard deviation of glycaemia values during initial hospitalisation in the intensive cardiac care unit. MACE, including recurrent AHF, new-onset myocardial infarction, ischaemic stroke and cardiac death, were recorded. The predictive effects of GV on patient outcomes were analysed with respect to baseline characteristics and cardiac status. (3) Results: In total, 392 patients with diabetes and AHF were enrolled. During follow-up (median (interquartile range) 29 (6−51) months), MACE occurred in 227 patients (57.9%). In total, 92 patients died of cardiac causes (23.5%), 107 were hospitalised for heart failure (27.3%), 19 had new-onset myocardial infarction (4.8%) and 9 (2.3%) had an ischaemic stroke. Multivariable logistic regression analysis showed that GV > 50 mg/dL (2.70 mmol/L), age > 75 years, reduced left ventricular ejection fraction (LVEF < 30%) and female gender were independent predictors of MACE: hazard ratios (HR) of 3.16 (2.25−4.43; p < 0.001), 1.54 (1.14−2.08; p = 0.005), 1.47 (1.06−2.07; p = 0.02) and 1.43 (1.05−1.94; p = 0.03), respectively. (4) Conclusions: among other well-known factors of HF, a GV cut-off value of >50 mg/dL was the strongest independent predictive factor for mid-term MACE in patients with diabetes and AHF.

Impact of COVID-19 Lockdown on the Metabolic Control Parameters in Patients with Diabetes Mellitus: A Systematic Review and Meta-Analysis

BACKGROUND

Abrupt implementation of lockdowns during the coronavirus disease 2019 (COVID-19) pandemic affected the management of diabetes mellitus in patients worldwide. Limited access to health facilities and lifestyle changes potentially affected metabolic parameters in patients at risk. We conducted a meta-analysis to determine any differences in the control of metabolic parameters in patients with diabetes, before and during lockdown.

METHODS

We performed searches of five databases. Meta-analyses were carried out using random- or fixed-effect approaches to glycaemic control parameters as the primary outcome: glycosylated hemoglobin (HbA1c), random blood glucose (RBG), fasting blood glucose (FBG), time-in-range (TIR), time-above-range (TAR), time-below-range (TBR). Mean difference (MD), confidence interval (CI), and P value were calculated. Lipid profile was a secondary outcome and is presented as a descriptive analysis.

RESULTS

Twenty-one studies enrolling a total of 3,992 patients with type 1 or type 2 diabetes mellitus (T1DM or T2DM) were included in the study. Patients with T1DM showed a significant improvement of TIR and TAR (MD=3.52% [95% CI, 0.29 to 6.74], I2=76%, P=0.03; MD=-3.36% [95% CI, -6.48 to -0.25], I2=75%, P=0.03), while FBG among patients with T2DM significantly worsened (MD=3.47 mg/dL [95% CI, 1.22 to 5.73], I2=0%, P<0.01). No significant difference was found in HbA1c, RBG, and TBR. Use of continuous glucose monitoring in T1DM facilitated good glycaemic control. Significant deterioration of lipid parameters during lockdown, particularly triglyceride, was observed.

CONCLUSION

Implementation of lockdowns during the COVID-19 pandemic did not worsen glycaemic control in patients with diabetes. Other metabolic parameters improved during lockdown, though lipid parameters, particularly triglyceride, worsened.

HbA1c variability predicts cardiovascular complications in type 2 diabetes regardless of being at glycemic target

Background

HbA1c variability has emerged as risk factor for cardiovascular diseases in diabetes. However, the impact of HbA1c variability on cardiovascular diseases in subjects within the recommended HbA1c target has been relatively unexplored.

Methods

Using data from a large database, we studied 101,533 people with type 2 diabetes without cardiovascular diseases. HbA1c variability was expressed as quartiles of the standard deviation of HbA1c during three years (exposure phase). The primary composite outcome included non-fatal myocardial infarction, non-fatal stroke, all-cause mortality and was assessed during five years following the first three years of exposure to HbA1c variability (longitudinal phase). An expanded composite outcome including non-fatal myocardial infarction, non-fatal stroke, coronary revascularization/reperfusion procedures, peripheral revascularization procedures, and all-cause mortality was also considered, as well as a series of specific cardiovascular complications. Cox models were adjusted for a large range of risk factors and results were expressed as adjusted hazard ratios.

Results

An association between HbA1c variability and all the outcomes considered was found. The correlation between HbA1c variability and cardiovascular complications development was confirmed in both the subgroups of subjects with a mean HbA1c ≤ 53 mmol/mol (recommended HbA1c target) or > 53 mmol/mol during the exposure phase. The risk related to HbA1c variability was higher in people with mean HbA1c ≤ 53 mmol/mol for the primary outcome (p for interaction 0.004), for the expanded secondary outcome (p for interaction 0.001) and for the stroke (p for interaction 0.001), even though HbA1c remained at the target during the follow-up.

Conclusions

These findings suggest that HbA1c variability may provide additional information for an optimized management of diabetes, particularly in people within the target of HbA1c.

Supplementary Information

The online version contains supplementary material available at 10.1186/s12933-022-01445-4.

Old and New Biomarkers Associated with Endothelial Dysfunction in Chronic Hyperglycemia

Chronic hyperglycemia and vascular damage are strictly related. Biomarkers of vascular damage have been intensively studied in the recent years in the quest of reliable cardiovascular risk assessment tools able to facilitate risk stratification and early detection of vascular impairment. The present study is a narrative review with the aim of revising the available evidence on current and novel markers of hyperglycemia-induced vascular damage. After a discussion of classic tools used to investigate endothelial dysfunction, we provide an in-depth description of novel circulating biomarkers (chemokines, extracellular vesicles, and epigenetic and metabolomic biomarkers). Appropriate use of a single as well as a cluster of the discussed biomarkers might enable in a near future (a) the prompt identification of targeted and customized treatment strategies and (b) the follow-up of cardiovascular treatment efficacy over time in clinical research and/or in clinical practice.

Association between Variability of Metabolic Risk Factors and Cardiometabolic Outcomes

Despite strenuous efforts to reduce cardiovascular disease (CVD) risk by improving cardiometabolic risk factors, such as glucose and cholesterol levels, and blood pressure, there is still residual risk even in patients reaching treatment targets. Recently, researchers have begun to focus on the variability of metabolic variables to remove residual risks. Several clinical trials and cohort studies have reported a relationship between the variability of metabolic parameters and CVDs. Herein, we review the literature regarding the effect of metabolic factor variability and CVD risk, and describe possible mechanisms and potential treatment perspectives for reducing cardiometabolic risk factor variability.

The Role of p66Shc in Diabetes: A Comprehensive Review from Bench to Bedside

It is well-documented that diabetes is an inflammatory and oxidative disease, with an escalating global burden. Still, there is no definite treatment for diabetes or even prevention of its harmful complications. Therefore, understanding the molecular pathways associated with diabetes might help in finding a solution. p66Shc is a member of Shc family proteins, and it is considered as an oxidative stress sensor and regulator in cells. There are inconsistent data about the role of p66Shc in inducing diabetes, but accumulating evidence supports its role in the pathogenesis of diabetes-related complications, including macro and microangiopathies. There is growing hope that by understanding and targeting molecular pathways involved in this network, prevention of diabetes or its complications would be achievable. This review provides an overview about the role of p66Shc in the development of diabetes and its complications.

Glycaemic management in diabetes: old and new approaches

HbA_1c is the most used parameter to assess glycaemic control. However, evidence suggests that the concept of hyperglycaemia has profoundly changed and that different facets of hyperglycaemia must be considered. A modern approach to glycaemic control should focus not only on reaching and maintaining optimal HbA_1c concentrations as early as possible, but to also do so by reducing postprandial hyperglycaemia, glycaemic variability, and to extend as much as possible the time in range in near-normoglycaemia. These goals should be achieved while avoiding hypoglycaemia, which, should it occur, should be reverted to normoglycaemia. Modern technology, such as intermittently scanned glucose monitoring and continuous glucose monitoring, together with new drug therapies (eg, ultra-fast insulins, SGLT2 inhibitors, and GLP-1 receptor agonists), could help to change the landscape of glycaemia management based on HbA_1c in favour of a more holistic approach that considers all the different aspects of this commonly oversimplified pathophysiological feature of diabetes.

Effect of chiglitazar and sitagliptin on glucose variations, insulin resistance and inflammatory-related biomarkers in untreated patients with type 2 diabetes

AIMS

To evaluate glycemic variations, changes in insulin resistance and oxidative stress after chiglitazar or sitagliptin treatment in untreated patients with type 2 diabetes mellitus (T2DM).

METHODS

Based on the study inclusion and exclusion criteria, 81 patients with T2DM were randomly divided to receive chiglitazar or sitagliptin treatment for 24 weeks. Continuous glucose monitoring (CGM) systems were conducted for 72 h in eligible patients. We analyzed the following glycemic variation parameters derived from the CGM data and measured the serum levels of hemoglobin A1c (HbA1c), fasting blood glucose (FBG), 2-h postprandial blood glucose (2-h PBG), fasting insulin (Fins) and inflammatory-related indicators at baseline and the end of the study.

RESULTS

After treatment for 24 weeks, our data showed a similar reduction in HbA1c between chiglitazar and sitagliptin. The 24-h mean blood glucose (MBG), standard deviation (SD) and mean amplitude of glycemic excursion (MAGE) were significantly decreased, and the time in range (TIR) was increased after chiglitazar and sitagliptin therapy. Chiglitazar administration led to significant improvement in insulin resistance/insulin secretion (HOMA-IR, HOMA-IS), interleukin-6 (IL-6), prostaglandin F2α (PGF-2α), 17-hydroxyprogesterone (17-OHP) and adiponectin (ADP) score values compared with sitagliptin administration.

CONCLUSIONS

Chiglitazar therapy effectively reduced glucose variation and showed a larger improvement in insulin resistance and inflammatory parameters than sitagliptin.

Inflammation in Coronary Microvascular Dysfunction

Chronic low-grade inflammation is involved in coronary atherosclerosis, presenting multiple clinical manifestations ranging from asymptomatic to stable angina, acute coronary syndrome, heart failure and sudden cardiac death. Coronary microvasculature consists of vessels with a diameter less than 500 μm, whose potential structural and functional abnormalities can lead to inappropriate dilatation and an inability to meet the required myocardium oxygen demands. This review focuses on the pathogenesis of coronary microvascular dysfunction and the capability of non-invasive screening methods to detect the phenomenon. Anti-inflammatory agents, such as statins and immunomodulators, including anakinra, tocilizumab, and tumor necrosis factor-alpha inhibitors, have been assessed recently and may constitute additional or alternative treatment approaches to reduce cardiovascular events in atherosclerotic heart disease characterized by coronary microvascular dysfunction.

Microvascular Inflammation and Cardiovascular Prevention: The Role of Microcirculation as Earlier Determinant of Cardiovascular Risk

Healthcare systems encumbered by cardiovascular diseases demand adequate cardiovascular prevention. Indeed, even with the most novel therapies, the residual cardiovascular risk still fuels morbidity and mortality. Addressing inflammation as a putative mediator of this risk has brought along promising in vitro results, though large clinical trials have only in part confirmed them. To fully exploit the therapeutic potential between the inflammatory hypothesis, a change of viewpoint is required. Focus on microcirculation, whose dysfunction is the primary driver of cardiometabolic disease, is mandatory. Several factors play a pivotal role in the capacity of microvascular inflammation to promote a health-to-disease transition: the adipose tissue (in particular, perivascular and epicardial), the mitochondria function, the hyperglycemic damage and their epigenetic signature. Indeed, the low-grade inflammatory response, which is now an acknowledged hallmark of cardiometabolic disease, is promoted by these mediators and leaves a permanent epigenetic scar on the microvasculature. Even if a more profound knowledge about the mechanisms of metabolic memory has been brought to light by recent evidence, we still have to fully understand its mechanisms and clinical potential. Addressing the detrimental role of inflammation by targeting the microvascular phenotype and leveraging epigenetics is the road down which we must go to achieve satisfactory cardiovascular prevention, ultimately leading to disease-free ageing.

Microvascular Ageing Links Metabolic Disease to Age-Related Disorders: The Role of Oxidative Stress and Inflammation in Promoting Microvascular Dysfunction

ABSTRACT

Longer life span and increased prevalence of chronic, noncommunicable, inflammatory diseases fuel cardiovascular mortality. The microcirculation is central in the cross talk between ageing, inflammation, cardiovascular, and metabolic diseases. Microvascular dysfunction, characterized by alteration in the microvascular endothelial function and wall structure, is described in an increasing number of chronic age-associated diseases, suggesting that it might be a marker of ageing superior to chronological age. The aim of this review is to thoroughly explore the connections between microvascular dysfunction, ageing, and metabolic disorders by detailing the major role played by inflammation and oxidative stress in their evolution. Older age, hypertension, nutrient abundance, and hyperglycemia concur in the induction of a persistent low-grade inflammatory response, defined as meta-inflammation or inflammageing. This increases the local generation of reactive oxygen species that further impairs endothelial function and amplifies the local inflammatory response. Mitochondrial dysfunction is a hallmark of many age-related diseases. The alterations of mitochondrial function promote irreversible modification in microvascular structure. The interest in the hypothesis of chronic inflammation at the center of the ageing process lies in its therapeutic implications. Inhibition of specific inflammatory pathways has been shown to lower the risk of many age-related diseases, including cardiovascular disease. However, the whole architecture of the inflammatory response underpinning the ageing process and its impact on the burden of age-related diseases remain to be fully elucidated. Additional studies are needed to unravel the connection between these biological pathways and to address their therapeutic power in terms of cardiovascular prevention.

Vascular repair and regeneration in cardiometabolic diseases

Chronic cardiometabolic assaults during type 2 diabetes (T2D) and obesity induce a progenitor cell imbalance in the circulation characterized by overproduction and release of pro-inflammatory monocytes and granulocytes from the bone marrow alongside aberrant differentiation and mobilization of pro-vascular progenitor cells that generate downstream progeny for the coordination of blood vessel repair. This imbalance can be detected in the peripheral blood of individuals with established T2D and severe obesity using multiparametric flow cytometry analyses to discern pro-inflammatory vs. pro-angiogenic progenitor cell subsets identified by high aldehyde dehydrogenase activity, a conserved progenitor cell protective function, combined with lineage-restricted cell surface marker analyses. Recent evidence suggests that progenitor cell imbalance can be reversed by treatment with pharmacological agents or surgical interventions that reduce hyperglycaemia or excess adiposity. In this state-of-the-art review, we present current strategies to assess the progression of pro-vascular regenerative cell depletion in peripheral blood samples of individuals with T2D and obesity and we summarize novel clinical data that intervention using sodium-glucose co-transporter 2 inhibition or gastric bypass surgery can efficiently restore cell-mediated vascular repair mechanisms associated with profound cardiovascular benefits in recent outcome trials. Collectively, this thesis generates a compelling argument for early intervention using current pharmacological agents to prevent or restore imbalanced circulating progenitor content and maintain vascular regenerative cell trafficking to sites of ischaemic damage. This conceptual advancement may lead to the design of novel therapeutic approaches to prevent or reverse the devastating cardiovascular comorbidities currently associated with T2D and obesity.

Effect of glycemic control on markers of subclinical atherosclerosis in patients with type 2 diabetes mellitus: A review

Cardiovascular disease is the predominant cause of death in type 2 diabetes mellitus (T2DM). Evidence suggests a strong association between duration and degree of hyperglycemia and vascular disease. However, large trials failed to show cardiovascular benefit after intensive glycemic control, especially in patients with longer diabetes duration. Atherosclerosis is a chronic and progressive disease, with a long asymptomatic phase. Subclinical atherosclerosis, which is impaired in T2DM, includes impaired vasodilation, increased coronary artery calcification (CAC), carotid intima media thickness, arterial stiffness, and reduced arterial elasticity. Each of these alterations is represented by a marker of subclinical atherosclerosis, offering a cost-effective alternative compared to classic cardiac imaging. Their additional use on top of traditional risk assessment strengthens the predictive risk for developing coronary artery disease (CAD). We, herein, review the existing literature on the effect of glycemic control on each of these markers separately. Effective glycemic control, especially in earlier stages of the disease, attenuates progression of structural markers like intima-media thickness and CAC. Functional markers are improved after use of newer anti-diabetic agents, such as incretin-based treatments or sodium-glucose co-transporter-2 inhibitors, especially in T2DM patients with shorter disease duration. Larger prospective trials are needed to enhance causal inferences of glycemic control on clinical endpoints of CAD.

Effects of phloridzin on blood glucose and key enzyme G-6-Pase of gluconeogenesis in mice

The effects of phloridzin (PHL), main component of Malus hupehensis (MH) tea leaves, on blood glucose (BG) and glucose-6-phosphatase (G-6-Pase) were investigated to provide a basis for finding a scheme of stabilizing BG. Glucose uptake of insulin resistant HepG2 cells was measured by glucose oxidase method. Glucose tolerance, fasting BG (FBG) and postprandial BG (PBG) were determined by BG test strips. The expression of G-6-Pase was detected by Western blot. The results showed that glucose uptake was enhanced and the expression of G-6-Pase was inhibited by PHL in insulin resistant HepG2 cells. Glucose tolerance was enhanced, FBG level was increased and PBG level was decreased by PHL in mice. The expression of G-6-Pase in the liver was enhanced under fasting state, and was inhibited by the low and medium dose under postprandial state. It indicated that PHL has a positive effect on stabilizing BG in mice, which is related to bidirectional regulation of G-6-Pase activity. PRACTICAL APPLICATIONS: Malus hupehensis, edible and medicinal plant, which has been proved by long-term application and experiments that it has a good effect on stabilizing blood glucose, preventing diabetes and adjuvant treatment. Its effect is closely related to its main component PHL. Thus, MH can be used as a dietary regulating drink for daily life to maintain blood glucose. Its main ingredient is PHL, which can be developed as a candidate drug for diabetes treatment.