Acute glycemic variability on admission predicts the prognosis in hospitalized patients with coronary artery disease: a meta-analysis

Research progress on the association between glycemic variability index derived from CGM and cardiovascular disease complications

Currently, glycated hemoglobin A1c (HbA1c) has been widely used to assess the glycemic control of patients with diabetes. However, HbA1c has certain limitations in describing both short-term and long-term glycemic control. To more accurately evaluate the glycemic control of diabetes patients, the continuous glucose monitoring (CGM) technology has emerged. CGM technology can provide robust data on short-term glycemic control and introduce new monitoring parameters such as time in range, time above range, and time below range as indicators of glycemic fluctuation. These indicators are used to describe the changes in glycemic control after interventions in clinical research or treatment modifications in diabetes patient care. Recent studies both domestically and internationally have shown that these indicators are not only associated with microvascular complications of diabetes mellitus but also closely related to cardiovascular disease complications and prognosis. Therefore, this article aims to comprehensively review the association between CGM-based glycemic parameters and cardiovascular disease complications by analyzing a large number of domestic and international literature. The purpose is to provide scientific evidence and guidance for the standardized application of these indicators in clinical practice, in order to better evaluate the glycemic control of diabetes patients and prevent the occurrence of cardiovascular disease complications. This research will contribute to improving the quality of life for diabetes patients and provide important references for clinical decision-making.

Increased glycemic variability results in abnormal differentiation of T cell subpopulation in type 2 diabetes patients

AIMS

We aimed to investigate the association between glycemic variability (GV) and the abnormal differentiation of T-cell subpopulations in patients with type 2 diabetes mellitus (T2DM).

METHODS

In total, 108 hospitalized patients with T2DM were enrolled and divided into two subgroups (normal glycemic excursion (NGE) and high glycemic excursion (HGE)) according to their mean amplitude of glycemic excursion (MAGE) level. The MAGE was evaluated via continuous glucose monitoring for 72 h consecutively. Flow cytometry was used to determine the proportions of T cell subpopulations.

RESULTS

The T helper (Th) 1 cell/Th2 cell ratio was significantly higher, and the proportion of regulatory T cells (Tregs) was significantly lower in the NGE group than in the HGE group (all P < 0.05). After fully adjusting for confounders, the MAGE was positively associated with the Th1 cell/Th2 cell ratio (β = 0.370; P = 0.009) and negatively associated with the proportion of Tregs (β = -0.554; P = 0.001).

CONCLUSION

The MAGE was an independent risk factor for abnormally high Th1 cell/Th2 cell ratio and proportion of Tregs. Abnormal differentiation of T cell subpopulations induced by GV may impair β-cell function, aggravate insulin resistance, and contribute to the development of diabetic complications.

Impact of acute glycemic variability on short-term outcomes in patients with ST-segment elevation myocardial infarction: a multicenter population-based study

BACKGROUND

Given the increasing attention to glycemic variability (GV) and its potential implications for cardiovascular outcomes. This study aimed to explore the impact of acute GV on short-term outcomes in Chinese patients with ST-segment elevation myocardial infarction (STEMI).

METHODS

This study enrolled 7510 consecutive patients diagnosed with acute STEMI from 274 centers in China. GV was assessed using the coefficient of variation of blood glucose levels. Patients were categorized into three groups according to GV tertiles (GV1, GV2, and GV3). The primary outcome was 30-day all-cause death, and the secondary outcome was major adverse cardiovascular events (MACEs). Cox regression analyses were conducted to determine the independent correlation between GV and the outcomes.

RESULTS

A total of 7136 patients with STEMI were included. During 30-days follow-up, there was a significant increase in the incidence of all-cause death and MACEs with higher GV tertiles. The 30-days mortality rates were 7.4% for GV1, 8.7% for GV2 and 9.4% for GV3 (p = 0.004), while the MACEs incidence rates was 11.3%, 13.8% and 15.8% for the GV1, GV2 and GV3 groups respectively (p < 0.001). High GV levels during hospitalization were significantly associated with an increased risk of 30-day all-cause mortality and MACEs. When analyzed as a continuous variable, GV was independently associated with a higher risk of all-cause mortality (hazard ratio [HR] 1.679, 95% confidence Interval [CI] 1.005-2.804) and MACEs (HR 2.064, 95% CI 1.386-3.074). Additionally, when analyzed as categorical variables, the GV3 group was found to predict an increased risk of MACEs, irrespective of the presence of diabetes mellitus (DM).

CONCLUSION

Our study findings indicate that a high GV during hospitalization was significantly associated with an increased risk of 30-day all-cause mortality and MACE in Chinese patients with STEMI. Moreover, acute GV emerged as an independent predictor of increased MACEs risk, regardless of DM status.

Glycemic variability assessed using continuous glucose monitoring in individuals without diabetes and associations with cardiometabolic risk markers: A systematic review and meta-analysis

BACKGROUND & AIMS

Continuous glucose monitoring (CGM) provides data on short-term glycemic variability (GV). GV is associated with adverse outcomes in individuals with diabetes. Whether GV is associated with cardiometabolic risk in individuals without diabetes is unclear. We systematically reviewed the literature to assess whether GV is associated with cardiometabolic risk markers or outcomes in individuals without diabetes.

METHODS

Searches were performed in PubMed/Medline, Embase and Cochrane from inception through April 2022. Two researchers were involved in study selection, data extraction and quality assessment. Studies evaluating GV using CGM for ≥24 h were included. Studies in populations with acute and/or critical illness were excluded. Both narrative synthesis and meta-analyzes were performed, depending on outcome.

RESULTS

Seventy-one studies were included; the majority were cross-sectional. Multiple measures of GV are higher in individuals with compared to without prediabetes and GV appears to be inversely associated with beta cell function. In contrast, GV is not clearly associated with insulin sensitivity, fatty liver disease, adiposity, blood lipids, blood pressure or oxidative stress. However, GV may be positively associated with the degree of atherosclerosis and cardiovascular events in individuals with coronary disease.

CONCLUSION

GV is elevated in prediabetes, potentially related to beta cell dysfunction, but less clearly associated with obesity or traditional risk factors. GV is associated with coronary atherosclerosis development and may predict cardiovascular events and type 2 diabetes. Prospective studies are warranted, investigating the predictive power of GV in relation to incident disease. GV may be an important risk measure also in individuals without diabetes.

Comparative effects of fixed-dose mitiglinide/voglibose combination and glimepiride on vascular endothelial function and glycemic variability in patients with type 2 diabetes: A randomized controlled trial

INTRODUCTION

The aim of this study was to compare the effects of mitiglinide/voglibose with those of glimepiride on glycemic variability and vascular endothelial function in patients with type 2 diabetes.

MATERIALS AND METHODS

It was a multicenter, open-label, randomized, crossover study. Hospitalized patients received either mitiglinide/voglibose (three times daily administration of 10 mg mitiglinide and 0.2 mg voglibose) or glimepiride (once-daily 2 mg) in random order, each for 5 days. The reactive hyperemia index (RHI) and the mean amplitude of glycemic excursions (MAGE) were measured as co-primary endpoints using reactive hyperemia peripheral arterial tonometry and continuous glucose monitoring.

RESULTS

The analysis included 30 patients (15 in each group). The RHI was 1.670 ± 0.369 during treatment with mitiglinide/voglibose and 1.716 ± 0.492 during treatment with glimepiride, with no significant difference between the two. MAGE was significantly lower in the mitiglinide/voglibose group (47.6 ± 18.5 mg/dL) than in the glimepiride group (100.6 ± 32.2 mg/dL). Although the mean blood glucose levels over the entire 24 h period were comparable between the two groups, the use of mitiglinide/voglibose was associated with a lower standard deviation of mean glucose, coefficient of variation, and mean postprandial glucose excursion compared with glimepiride. The time below range (<70 mg/dL) and the time above range (>180, >200, and 250 mg/dL) were lower in the mitiglinide/voglibose group, while the time in range (70-180 mg/dL) was higher.

CONCLUSIONS

In our short-duration randomized crossover study, although not impacting vascular endothelial function, mitiglinide/voglibose demonstrated potential benefits in reducing glycemic variability, postprandial hyperglycemia, and hypoglycemia in patients with type 2 diabetes.

Association between perioperative glucose profiles assessed by the continuous glucose monitoring (CGM) system and prognosis in patients with ST-segment elevation myocardial infarction (STEMI): protocol for a cohort study

INTRODUCTION

ST-segment elevation myocardial infarction (STEMI) presents a serious cardiovascular condition requiring prompt intervention. Dysglycaemia has been identified as a significant risk factor impacting STEMI prognosis. However, limited research has focused on comprehensively examining the association between glucose dynamics during the perioperative period and patient outcomes. This study aims to address this gap by leveraging continuous glucose monitoring (CGM) technology to gain real-time insights into glucose fluctuations and their potential impact on STEMI prognosis.

METHODS AND ANALYSIS

This is a multicentre, prospective, 3-year follow-up cohort study. Between May 2023 and May 2024, 550 eligible STEM patients who underwent percutaneous coronary intervention are expected to be recruited. Using the CGM system, continuous glucose levels will be collected throughout the perioperative phase. Key clinical parameters, including cardiac biomarkers, angiographic findings and major adverse cardiovascular events, will be assessed in relation to glucose profile.

ETHICS AND DISSEMINATION

The study was approved by the Medical Research Ethics Committee of The First Affiliated Hospital of University of Science and Technology of China and will be conducted in accordance with the moral, ethical and scientific principles of the Declaration of Helsinki. Written informed consent will be obtained from all participants before any study-related procedures are implemented. Study results will be disseminated through conferences and peer-reviewed scientific journals.

TRIAL REGISTRATION NUMBER

ChiCTR2300069662.

A synthesis of pathways linking diet, metabolic risk and cardiovascular disease: a framework to guide further research and approaches to evidence-based practice

Cardiovascular disease (CVD) is the most common non-communicable disease occurring globally. Although previous literature has provided useful insights into the important role that diet plays in CVD prevention and treatment, understanding the causal role of diets is a difficult task considering inherent and introduced weaknesses of observational (e.g. not properly addressing confounders and mediators) and experimental research designs (e.g. not appropriate or well designed). In this narrative review, we organised current evidence linking diet, as well as conventional and emerging physiological risk factors, with CVD risk, incidence and mortality in a series of diagrams. The diagrams presented can aid causal inference studies as they provide a visual representation of the types of studies underlying the associations between potential risk markers/factors for CVD. This may facilitate the selection of variables to be considered and the creation of analytical models. Evidence depicted in the diagrams was systematically collected from studies included in the British Nutrition Task Force report on diet and CVD and database searches, including Medline and Embase. Although several markers and disorders linked to conventional and emerging risk factors for CVD were identified, the causal link between many remains unknown. There is a need to address the multifactorial nature of CVD and the complex interplay between conventional and emerging risk factors with natural and built environments, while bringing the life course into the spotlight.

Glycemic Variability and Prognosis of Patients with Intracerebral Hemorrhage: A Meta-Analysis

Glycemic disorder may affect the outcomes of patients with intracerebral hemorrhage (ICH). However, the association between glycemic variability (GV) and prognosis in these patients remains to be determined. We performed a meta-analysis to compressive the influence of GV on functional outcome and mortality in patients with ICH. Observational studies comparing the risks of poor functional outcome (defined as modified Rankin Scale>2) and all-cause mortality between ICH patients with higher versus lower acute GV were retrieved by systematic search of Medline, Web of Science, Embase, CNKI, and Wanfang databases. A random-effect model was used to pool the data after incorporating the between-study heterogeneity. Sensitivity analyses were performed to evaluate the stability of the findings. Eight cohort studies involving 3400 patients with ICH were included in the meta-analysis. The follow-up duration was within 3 months after admission. All of the included studies used standard deviation of blood glucose (SDBG) as the indicator of acute GV. Pooled results showed that ICH patients with higher SDBG were associated with a higher risk of poor functional outcome as compared to those with lower SDBG [risk ratio (RR): 1.84, 95% confidence interval (CI): 1.41 to 2.42, p<0.001, I2=0%]. In addition, patients with higher category of SDBG were also associated with a higher mortality risk (RR: 2.39, 95% CI: 1.79 to 3.19, p<0.001, I2=0%). In conclusion, high acute GV may be a predictor of poor functional outcome and mortality of patients with ICH.

Glycaemic variability and risk of adverse cardiovascular events in acute coronary syndrome

OBJECTIVE

The relationship between different glycaemic variability (GV) indexes and adverse cardiovascular outcomes is not well understood. This study aims to determine whether GV is related to the occurrence of adverse cardiovascular events in patients with acute coronary syndrome (ACS).

METHODS

PubMed, EMBASE, and Web of Science were comprehensively searched from the establishment of databases to 29 June 2022. The relationship between two important GV indexes, including the mean amplitude of glycemic excursion (MAGE) and standard deviation (SD), and the adverse cardiovascular events in ACS patients were evaluated, respectively.

RESULTS

A total of 11 studies with 3709 ACS patients were included. Pooled results showed that patients with higher GV had significantly increased risk of adverse cardiovascular events, including MAGE (relative risk [RR] = 1.76, 95% CI: 1.40 to 2.22, p < 0.001, I² = 25%) and SD (RR = 2.14, 95% CI: 1.73 to 2.66, p < 0.001, I² = 0%).

CONCLUSIONS

Increased GV is related to the poor prognosis in patients with ACS. Additionally, more well-designed studies comparing different indicators of GV with adverse cardiovascular events in ACS patients are still warranted.

Prognostic value of glycemic gap in patients with spontaneous intracerebral hemorrhage

BACKGROUND

Glycemic gap (GG), as a novel biomarker showing the acute glycemic change after the onset of acute illness, has been found to be associated with adverse outcomes in many diseases. This study aimed to explore the prognostic value of GG on long-term outcomes of spontaneous intracerebral hemorrhage (sICH).

METHODS

The current study included 528 patients from a multi-center, prospective, consecutive, observational cohort study. Poor clinical outcome was defined as the modified Rankin Scale ≥ 3. GG was calculated using admission blood glucose minus hemoglobin A1c-derived average blood glucose. Logistic regression analyses were performed to determine the association between GG and poor clinical outcomes at 30-day, 90-day and 1-year.

RESULTS

GG was significantly associated with poor clinical outcomes at 30-day, 90-day, and 1-year (P < 0.05 for all models), where patients with higher GG were more likely to have poor clinical outcome. Restricted cubic splines revealed a positive association between GG and poor clinical outcome. In addition, patients with higher GG were more likely to have a higher 1-year mortality rate. The addition of GG to the intracerebral hemorrhage score improved the discrimination and calibration properties for the prediction of poor clinical outcome.

CONCLUSIONS

GG was independently associated with poor outcomes and may be a valuable prognostic factor in patients with sICH.

Relation of glucose variability to vulnerable plaque formation in patients with coronary artery disease

BACKGROUND

Although glucose variability (GV) is reportedly associated with coronary plaque vulnerability, namely lipid-rich plaque, details are not fully understood. The aim of this study was to evaluate relations of GV after discharge to vulnerable plaque formation assessed by near-infrared spectroscopy intravascular ultrasound (NIRS-IVUS) in patients with and without diabetes.

METHODS

A total of 40 patients undergoing percutaneous coronary intervention under NIRS-IVUS guidance were included, among whom 13 (33%) had diabetes and 20 (50%) presented with acute myocardial infarction (MI). GV was evaluated by a flush glucose monitoring system, primarily with mean amplitude of glycemic excursion (MAGE). Lipid-rich plaque was assessed by maximum lipid core burden index in 4 mm (maxLCBI_4mm) in the target lesion using NIRS-IVUS.

RESULTS

Mean MAGE and maxLCBI_4mm were 69.7 ± 25.6 mg/dl and 508.0 ± 294.9. Intra-day GV was not significantly associated with maxLCBI_4mm in the entire study population, while MAGE was correlated with maxLCBI_4mm in non-diabetic patients (r = 0.46, p = 0.02). In patients with and without acute MI presentation, no significant relations were found between MAGE and maxLCBI_4mm.

CONCLUSION

GV was associated with lipid core plaque formation, especially in non-diabetic patients.

Persistent Postgastrectomy Hypoglycemia Unawareness in Patients With Gastric Cancer Unveiled by a Prospective Study

Objective

Late dumping syndrome is a common postgastrectomy complication characterized by reactive hypoglycemia. This study aimed to explore the glycemic trend in patients who underwent gastrectomy for gastric cancer and clarify its changes over time in association with postgastrectomy symptoms.

Summary Background Data

Changes over time in glycemic trend in association with postgastrectomy symptoms have not been evaluated.

Methods

We conducted a prospective study of 71 patients who underwent curative gastrectomy for gastric cancer between November 2017 and April 2020. The patients underwent continuous glucose monitoring twice-at 1- and 12-month postgastrectomy-and were assessed using the Post-Gastrectomy Syndrome Assessment Scale 37-item questionnaire (PGSAS-37) at 1-, 6-, and 12-month postgastrectomy.

Results

Our results revealed that hypoglycemia (<70 mg/dL), especially nocturnal hypoglycemia (00:00-06:00), frequently occurred even at 12-month postgastrectomy. Hypoglycemia improved in total gastrectomy patients but remained unchanged in distal gastrectomy patients, which was still high in both groups at 12-month postgastrectomy. Glycemic variability (SD of the glycemic trend) was exacerbated in both gastrectomy groups. However, the PGSAS-37 symptom scores remained unchanged, and the living status and quality of life tended to improve. Hypoglycemia unawareness, including postprandial hypoglycemia without symptoms and nocturnal hypoglycemia, was evident even 12-month postgastrectomy.

Conclusions

Persistent postgastrectomy hypoglycemia unawareness, including late dumping syndrome without symptoms and nocturnal hypoglycemia, should be recognized as an important issue in postgastrectomy syndrome. Therefore, meticulous long-term evaluation for glycemic trends and care of patients is required.

Influence of dipeptidyl peptidase-4 inhibitors on glycemic variability in patients with type 2 diabetes: A meta-analysis of randomized controlled trials

OBJECTIVE

The influence of dipeptidyl peptidase-4 (DPP4) inhibitors on glycemic variability compared to other oral antidiabetic drugs (OADs), measured based on the mean amplitude of glycemic excursions (MAGE), has not been comprehensively analyzed. The aim of the study was to perform a meta-analysis to compare the effects of DPP4 inhibitors on MAGE with other OADs in type 2 diabetes mellitus (T2DM) patients without concurrent insulin treatments.

METHODS

The Medline (PubMed), Embase (Ovid), and CENTER (Cochrane Library) databases were searched for relevant randomized controlled trials (RCTs). Study characteristics and outcome data were independently extracted by two authors. A random-effect model was used to combine the results.

RESULTS

Fourteen studies with 855 patients were included. Compared to other OADs, DPP4 inhibitors significantly reduced MAGE (mean difference [MD]: -0.69 mmol/L, 95% confidence interval [CI]: -0.95 to -0.43, P<0.001) with mild heterogeneity (I^{2 =} 28%). Predefined subgroup analyses suggested that DPP4 inhibitors were more effective in reducing MAGE compared to insulin secretagogues (MD: -0.92 mmol/L, P<0.001) and non-secretagogues (MD: -0.43 mmol/L, P=0.02), as well as compared to sulfonylureas (MD: -0.91 mmol/L, P<0.001) and sodium glucose cotransporter 2 inhibitors (MD: -0.67 mmol/L, P=0.03).

CONCLUSIONS

DPP4 inhibitors may significantly reduce glycemic variability compared to other oral anti-diabetic drugs, as evidenced by MAGE in T2DM patients with no concurrent insulin treatment.

SYSTEMATIC REVIEW REGISTRATION

INPLASY, registration number: INPLASY2021120113.

Perspectives of glycemic variability in diabetic neuropathy: a comprehensive review

Diabetic neuropathy is one of the most prevalent chronic complications of diabetes, and up to half of diabetic patients will develop diabetic neuropathy during their disease course. Notably, emerging evidence suggests that glycemic variability is associated with the pathogenesis of diabetic complications and has emerged as a possible independent risk factor for diabetic neuropathy. In this review, we describe the commonly used metrics for evaluating glycemic variability in clinical practice and summarize the role and related mechanisms of glycemic variability in diabetic neuropathy, including cardiovascular autonomic neuropathy, diabetic peripheral neuropathy and cognitive impairment. In addition, we also address the potential pharmacological and non-pharmacological treatment methods for diabetic neuropathy, aiming to provide ideas for the treatment of diabetic neuropathy.

Zhang et al. describe metrics for evaluating glycaemic variability (GV) in clinical practice and summarize the role and related mechanisms of GV in diabetic neuropathy, including cardiovascular autonomic neuropathy, diabetic peripheral neuropathy and cognitive impairment. They aim to stimulate ideas for the treatment of diabetic neuropathy.

Glucose variability predicts 6-month mortality in patients hospitalized with acute heart failure

In diabetes mellitus (DM), glycaemic fluctuations associate with higher oxidative stress than sustained chronic hyperglycaemia and glucose variability increases the risk of chronic diabetic complications. Our hypothesis was that higher glucose variability would associate with mortality after an acute heart failure (HF) episode. We retrospectively analysed patients with DM hospitalized with acute HF between 2009 and 2010. Patients with < 2 point-of-care glucose values/day were excluded. Glucose coefficient of variation (GCV) was defined as (glucose standard deviation/mean glucose) × 100. Patients were categorized according GCV ≤ 30.0 and > 30.0%. Follow-up: 6-months. Endpoint: all-cause mortality. A Cox-regression analysis was used to study the association of glucose variability with 6-month mortality. We studied 214 diabetic patients with acute HF, 49.1% male, mean age 76 years. Mean glycaemia during hospitalization was 187 ± 50 mg/dL, hypoglycaemia (< 70 mg/dL) was reported in 21 patients and mean GCV was 28.3 ± 7.6%. Patients with GCV > 30.0% had higher mean glycaemia, more hypoglycaemic episodes and higher HbA1c; they were also more often treated with insulin. Patients were similar concerning age, gender, comorbidities, left ventricular systolic dysfunction and ischemic heart disease. During the 6-month follow-up, 38 (17.8%) patients died. Patients with GCV > 30.0% had a HR of 6-month mortality of 2.21 (95% CI: 1.16-4.21), p = 0.02. This association with more than twofold higher short-term mortality was independent of main confounders. Elevated glycaemic variability in acute HF admissions of patients with DM predicts short-term mortality. Patients with GCV > 30.0% have an independent more than twofold higher risk of 6-month death after an acute HF hospitalization.

Development of application to automatically calculate mean amplitude of glycaemic excursions using intermittently scanned continuous glucose monitoring data

AIM

We aimed to develop an application to calculate mean amplitude of glycaemic excursions (MAGE) automatically and to evaluate its accuracy.

MATERIALS AND METHODS

We named the application intermittently scanned continuous glucose monitoring (isCGM) calculator KAMOGAWA (Kyoto Auto MAGE Of Glucose cAlcutator With isCGM Application). The isCGM data from 20 patients, 10 with and 10 without diabetes, were used to compare manually calculated MAGE values with those calculated using KAMOGAWA. The rate of agreement for the MAGE values was calculated.

RESULTS

Comparing the MAGE values calculated manually with those calculated using KAMOGAWA, the total mean rate of agreement was 81.6%. Nonmatching values were checked and it was found that the inconsistencies were all attributable to errors in manual calculations. After correcting errors in the manual calculation, the MAGE values matched to one decimal place for all data in the manual and KAMOGAWA calculations.

CONCLUSIONS

KAMOGAWA can help diabetologists use MAGE in clinical practice, which could contribute to improving glycaemic control in patients who use isCGM.

Impact of glycemic variability on coronary and peripheral endothelial dysfunction in patients with coronary artery disease

BACKGROUND

Previous studies have reported that glucose variability leads to endothelial dysfunction and progression of coronary atherosclerosis. However, few studies have directly evaluated the relation between glucose variability and coronary endothelial function in patients with coronary artery disease (CAD).

METHODS

A total of 38 patients with chronic CAD and a history of coronary drug-eluting stent implantation were enroled. Coronary endothelial function was evaluated by measuring the coronary vasoreactivity using quantitative coronary angiography in the segment distal to implanted stent in response to intracoronary acetylcholine (ACh) infusion (10-7 mol/l). Peripheral endothelial function was also assessed with reactive hyperemia index (RHI). The mean amplitude of glycemic excursion (MAGE) was calculated as a primary metric of glucose variability using a flash glucose monitoring system.

RESULTS

Of 38 patients, 17 (45%) had diabetes mellitus. The mean levels of glycated hemoglobin, MAGE, and RHI were 6.3 ± 0.8%, 71.4 ± 29.8 mg/dl, and 1.85 ± 0.63. In the distal segment to coronary stent, lumen diameter was constricted by 0.6 ± 7.3% in response to intracoronary ACh infusion compared to that at baseline. While peripheral endothelial function assessed with RHI was not significantly associated with MAGE (r = -0.16, p = 0.35), coronary endothelial function was correlated with MAGE (r = -0.38, p = 0.02).

CONCLUSION

Greater glucose variability was significantly associated with coronary rather than peripheral endothelial dysfunction in patients with CAD, suggesting an impact of glucose variability on coronary atherosclerosis.

Metformin improves glycemic variability in adults with type 1 diabetes mellitus: an open-label randomized control trial

INTRODUCTION

Metformin has been demonstrated to enhance cardioprotective benefits in type 1 diabetes (T1DM). Although glycemic variability (GV) is associated with increased risk of CVD in diabetes, there is a scarcity of research evaluating the effect of metformin on GV in T1DM.

OBJECTIVES

In the present study, the effects of adjuvant metformin therapy on GV and metabolic control in T1DM were explored.

PATIENTS AND METHODS

A total of 65 adults with T1DM were enrolled and subjected to physical examination, fasting laboratory tests, and continuous glucose monitoring, and subsequently randomized 1:1 to 3 months of 1000-2000 mg metformin daily add-on insulin (MET group, n = 34) or insulin (non-MET group, n = 31). After, baseline measurements were repeated.

RESULTS

The mean amplitude of glycemic excursions was substantially reduced in MET group, compared with non-MET group (-1.58 (-3.35, 0.31) mmol/L vs 1.36 (-1.12, 2.24) mmol/L, P = 0.004). In parallel, the largest amplitude of glycemic excursions (-2.83 (-5.47, -0.06) mmol/L vs 0.45 (-1.29, 4.48) mmol/L, P = 0.004), the s.d. of blood glucose (-0.85 (-1.51, 0.01) mmol/L vs -0.14 (-0.68, 1.21) mmol/L, P = 0.015), and the coefficient of variation (-6.66 (-15.00, 1.50)% vs -1.60 (-6.28, 11.71)%, P = 0.012) all demonstrated improvement in the MET group, compared with the non-MET group. Significant reduction in insulin dose, BMI, and body weight was observed in patients in MET, not those in non-MET group.

CONCLUSION

Additional metformin therapy improved GV in adults with T1DM, as well as improving body composition and reducing insulin requirement. Hence, metformin as an adjunctive therapy has potential prospects in reducing the CVD risk in patients with T1DM in the long term.

Higher long-term visit-to-visit glycemic variability predicts new-onset atrial fibrillation in patients with diabetes mellitus

Background

Atrial fibrillation (AF) is prevalent in patients with type 2 diabetes mellitus (T2DM). Glycemic variability (GV) is associated with risk of micro- and macrovascular diseases. However, whether the GV can increase the risk of AF remains unknown.

Methods

The cohort study used a database from National Taiwan University Hospital, a tertiary medical center in Taiwan. Between 2014 and 2019, a total of 27,246 adult patients with T2DM were enrolled for analysis. Each individual was assessed to determine the coefficients of variability of fasting glucose (FGCV) and HbA1c variability score (HVS). The GV parameters were categorized into quartiles. Multivariate Cox regression models were employed to estimate the relationship between the GV parameters and the risk of AF, transient ischemic accident (TIA)/ischemic stroke and mortality in patients with T2DM.

Results

The incidence rates of AF and TIA/ischemic stroke were 21.31 and 13.71 per 1000 person-year respectively. The medium follow-up period was 70.7 months. In Cox regression model with full adjustment, the highest quartile of FGCV was not associated with increased risk of AF [Hazard ratio (HR): 1.12, 95% confidence interval (CI) 0.96–1.29, p = 0.148] or TIA/ischemic stroke (HR: 1.04, 95% CI 0.83–1.31, p = 0.736), but was associated with increased risk of total mortality (HR: 1.33, 95% CI 1.12–1.58, p < 0.001) and non-cardiac mortality (HR: 1.41, 95% CI 1.15–1.71, p < 0.001). The highest HVS was significantly associated with increased risk of AF (HR: 1.29, 95% CI 1.12–1.50, p < 0.001), total mortality (HR: 2.43, 95% CI 2.03–2.90, p < 0.001), cardiac mortality (HR: 1.50, 95% CI 1.06–2.14, p = 0.024) and non-cardiac mortality (HR: 2.80, 95% CI 2.28–3.44, p < 0.001) but was not associated with TIA/ischemic stroke (HR: 0.98, 95% CI 0.78–1.23, p = 0.846). The Kaplan–Meier analysis showed significantly higher risk of AF, cardiac and non-cardiac mortality according to the magnitude of GV (log-rank test, p < 0.001).

Conclusions

Our data demonstrate that high GV is independently associated with the development of new-onset AF in patients with T2DM. The benefit of maintaining stable glycemic levels to improve clinical outcomes warrants further studies.

Supplementary Information

The online version contains supplementary material available at 10.1186/s12933-021-01341-3.

Stress Induced Hyperglycemia in the Context of Acute Coronary Syndrome: Definitions, Interventions, and Underlying Mechanisms

Elevation of glucose level in response to acute coronary syndrome (ACS) has been recognized as stress induced hyperglycemia (SIH). Plenty of clinical studies have documented that SIH occurs very common in patients hospitalized with ACS, even in those without previously known diabetes mellitus. The association between elevated blood glucose levels with adverse outcome in the ACS setting is well-established. Yet, the precise definition of SIH in the context of ACS remains controversial, bringing confusions about clinical management strategy. Several randomized trials aimed to evaluate the effect of insulin-based therapy on outcomes of ACS patients failed to demonstrate a consistent benefit of intensive glucose control. Mechanisms underlying detrimental effects of SIH on patients with ACS are undetermined, oxidative stress might play an important role in the upstream pathways leading to subsequent harmful effects on cardiovascular system. This review aims to discuss various definitions of SIH and their values in predicting adverse outcome in the context of ACS, as well as the effect of intensive glucose control on clinical outcome. Finally, a glimpse of the underlying mechanisms is briefly discussed.

Elevated Glycated Albumin in Serum Is Associated with Adverse Cardiac Outcomes in Patients with Acute Coronary Syndrome Who Underwent Revascularization Therapy

Aims: The associations between increased glycated albumin (GA) in the serum and diabetic complications and mortality have been revealed in the general population. However, less is known regarding the prognostic value of GA in patients diagnosed with acute coronary syndrome (ACS).

Methods: In this study, all patients admitted for ACS who underwent a successful percutaneous coronary intervention (PCI) at our center from January 2018 to February 2019 were retrospectively examined. Clinical characteristics, laboratory results (e.g., serum GA levels), and procedural details were collected. The primary outcome included a composite of major adverse cardio-cerebral events (MACCE), such as death, myocardial infarction, stroke, and unplanned revascularization. The association between serum GA levels and clinical outcomes was tested in three multivariable models using Cox proportional hazard analysis. Subgroup analysis was performed in patients who were diagnosed with diabetes versus patients without diabetes.

Results: A total of 1,806 ACS patients (mean age of 59.4 years; 77.8% were men; 44.9% were diagnosed with diabetes) were enrolled in this study, where the majority exhibited unstable angina (81.6%) and showed preserved left ventricular systolic function. Patients in the high GA level group were commonly female and were more likely to have metabolic disorders and to exhibit severe CAD (all p ＜0.05). MACCE occurred in 126 patients (7.0%) during a mean follow-up time of 17.2 months. The cumulative risk of MACCE at the 18-month follow-up visit significantly increased in a stepwise fashion along with increased GA levels (log-rank p =0.018) in the serum. The association between serum GA levels and MACCE was further determined after adjusting traditional risk factors and hemoglobin A1c (HbA1c) (GA, per 1% increase: hazard ratio [HR] 1.09, 95% confidence interval [CI] 1.06–1.13; GA, higher vs. lower tertial: HR 1.92, 95% CI 1.01–3.67). In a subgroup analysis, the prognostic role of serum GA only existed in diabetic patients, even when adjusting for traditional risk factors and HbA1c levels.

Conclusions: Elevated GA levels in the serum were associated with poor intermediate-term outcomes in low-risk ACS patients who underwent PCI, especially in patients with preexisting diabetes.

Comprehensive elaboration of glycemic variability in diabetic macrovascular and microvascular complications

Diabetes mellitus is the major risk factor for the development of macrovascular and microvascular complications. It is increasingly recognized that glycemic variability (GV), referring to oscillations in blood glucose levels and representing either short-term or long-term GV, is involved in the pathogenesis of diabetic complications and has emerged as a possible independent risk factor for them. In this review, we summarize the metrics and measurement of GV in clinical practice, as well as comprehensively elaborate the role and related mechanisms of GV in diabetic macrovascular and microvascular complications, aiming to provide the mechanism-based therapeutic strategies for clinicians to manage diabetes mellitus.

Single prognostic cut-off value for admission glycemia in acute myocardial infarction has been used although high-risk stems from hyperglycemia as well as from hypoglycemia (a narrative review)

All original articles and meta-analysis use the single cut-off value to distinguish high-risk hyperglycemic from other acute myocardial infarction (AMI) patients. The mortality rate is 3.9 times higher in non-diabetic AMI patients with admission glycemia ≥6.1mmol compared to normoglycemic non-diabetic AMI patients. On the other hand, admission hypoglycemia in AMI is an important predictor of mortality. Because both admission hypo- and hyperglycemia correspond to higher in-hospital mortality, this graph is recognized as "J or U shaped curve". The review suggests two cut-off values for admission glycemia for risk assessment in AMI instead of single one because hypoglycemia as well as hyperglycemia represents a high-risk factor.

The effects of glycaemic variability on intimal hyperplasia and plaque stability after stenting via autophagy-mediated G3BP1/NLRP3 inflammasome

Background

The objective of this study was to investigate the effects of glycaemic variability (GV) on intimal hyperplasia and plaque stability after coronary stenting via autophagy-mediated G3BP1/NLRP3 inflammasome signalling.

Methods

In the clinical study, between July 2017 and December 2017, 95 patients with acute myocardial infarction (AMI) and diabetes mellitus (DM) comorbidity received stent implantation. The patients were followed up for 2 years after discharge. The patients were divided into a low-GV (n=61) and high-GV (n=34) group, and the incidence of recurrent AMI was measured. In the animal study, thirteen pigs were divided into a sham (n=3), low-GV DM (n=5) and high-GV DM group (n=5). Intima samples were analysed by optical coherence tomography 22 weeks after coronary stenting. Becn1, LC3B, p62, G3BP1 and NLRP3 protein levels in the intima were examined by western blot. In vitro experiments with THP-1 cells were also conducted.

Results

In the high-GV group, patients exhibited a higher recurrent AMI, greater neointimal thickness, increased p62 and NLRP3 expression, and decreased Becn1, LC3B and G3BP1 expression compared with the low-GV group (P<0.05). The effects of high GV could be abolished by rapamycin but were aggravated by 3-methyladenine.

Conclusions

GV might impact the intimal hyperplasia and plaque stability via autophagy-mediated G3BP1/NLRP3 inflammasome signalling. GV and the autophagy-mediated G3BP1/NLRP3 inflammasome may be promising targets for the treatment of coronary heart disease.

Visit-to-visit HbA1c variability is associated with in-stent restenosis in patients with type 2 diabetes after percutaneous coronary intervention

Background

Patients with type 2 diabetes are under substantially higher risk of in-stent restenosis (ISR) after coronary stent implantation. We sought to investigate whether visit-to-visit HbA_1c variability is a potential predictor of ISR in diabetic patients after stent implantation.

Methods

We consecutively enrolled type 2 diabetic patients who underwent successful elective percutaneous coronary intervention and performed follow-up coronary angiography after around 12 months. The incidence of ISR and its relationship with visit-to-visit HbA_1c variability, expressed as coefficient of variation (CV), standard deviation (SD) and variability independent of the mean (VIM), were studied. Multivariable Cox proportional hazards models were constructed to analyze the predictive value of HbA_1c variability for ISR.

Results

From September 2014 to July 2018 in Ruijin Hospital, a total of 420 diabetic patients (688 lesions) after stent implantation were included in the final analysis. During a mean follow-up of 12.8 ± 1.3 months, the incidence of ISR was 8.6%, which was significantly increased in patients with higher CV of HbA_1c (P = 0.001). The mean diameter stenosis (DS), net luminal loss and net luminal gain were 22.9 ± 16.8%, 0.42 ± 0.88 mm and 1.66 ± 0.83 mm, respectively. Greater DS was observed in subjects with higher tertiles of CV of HbA_1c (P < 0.001), and this trend was more prominent in patients with optimal glycemic control (HbA_1c ≤ 7%) in the baseline. In multivariate analysis, HbA_1c variability was independently associated with incidence of ISR after adjustment for traditional risk factors and mean HbA_1c (HR: 3.00 [95% CI 1.14–7.92] for highest vs. lowest tertile). Inclusion of CV of HbA_1c led to a better risk stratification accuracy. Assessing HbA_1c variability by SD or VIM yielded similar findings.

Conclusions

This study suggests that visit-to-visit HbA_1c variability is an independent predictor of incidence of ISR in patients with type 2 diabetes after stent implantation.

Trial registration NCT02089360: NCT

Glycemic variability: adverse clinical outcomes and how to improve it?

Glycemic variability (GV), defined as an integral component of glucose homoeostasis, is emerging as an important metric to consider when assessing glycemic control in clinical practice. Although it remains yet no consensus, accumulating evidence has suggested that GV, representing either short-term (with-day and between-day variability) or long-term GV, was associated with an increased risk of diabetic macrovascular and microvascular complications, hypoglycemia, mortality rates and other adverse clinical outcomes. In this review, we summarize the adverse clinical outcomes of GV and discuss the beneficial measures, including continuous glucose monitoring, drugs, dietary interventions and exercise training, to improve it, aiming at better addressing the challenging aspect of blood glucose management.