Association between daily glucose fluctuation and coronary plaque properties in patients receiving adequate lipid-lowering therapy assessed by continuous glucose monitoring and optical coherence tomography

Continuous glucose monitoring-derived time in range and CV are associated with altered tissue characteristics of the carotid artery wall in people with type 2 diabetes

AIMS/HYPOTHESIS

Previous studies have suggested that glucose variability may accelerate atherosclerosis progression in people with type 2 diabetes. Current guidelines recommend assessing glycaemic control using continuous glucose monitoring (CGM), which provides a comprehensive glycaemic profile to supplement HbA1c measurement. However, the association between CGM-derived metrics and atherosclerosis progression is not entirely clear.

METHODS

This exploratory study used baseline data and data obtained after 104 weeks from an ongoing prospective, multicentre, observational study. Six hundred study participants with type 2 diabetes and no apparent history of symptomatic cardiovascular disease underwent CGM and ultrasonographic atherosclerosis measurements of the carotid arteries, including the intima-media thickness (IMT) and grey-scale median (GSM), at baseline and 104 weeks. Non-invasive ultrasonic tissue characterisation of the carotid artery wall or plaque using the GSM reflects vascular composition. Multivariate regression models were used to analyse the association between CGM-derived indices, mainly time in range (TIR) and CV, and changes in carotid atherosclerosis index values.

RESULTS

Over the 104-week study period, there were modest increases in mean IMT (from 0.759±0.153 to 0.773±0.152 mm, p<0.001) and thickened-lesion GSM (from 43.5±19.5 to 53.9±23.5 units, p<0.001), but no significant changes in common carotid artery maximum-IMT (from 1.109±0.442 to 1.116±0.469 mm, p=0.453) or mean GSM (from 48.7±19.3 to 49.8±20.8 units, p=0.092). In a linear regression model with adjustment for possible atherosclerotic risk factors, including HbA1c, TIR and CV at baseline were significantly associated with the annual change in mean GSM (regression coefficient per 10% increase in TIR 0.52; 95% CI 0.06, 0.98; Hochberg-adjusted p value 0.038; regression coefficient per 1% increase in CV -0.12; 95% CI -0.22, -0.02; Hochberg-adjusted p value 0.038). TIR and CV at baseline were also significantly associated with the annual change in thickened-lesion GSM (regression coefficient per 10% increase in TIR 0.95; 95% CI 0.12, 1.79; Hochberg-adjusted p value 0.038; regression coefficient per 1% increase in CV -0.19; 95% CI -0.36, -0.01; Hochberg-adjusted p value 0.038). Participants who achieved target CGM-derived metrics at baseline, as proposed by an international consensus, showed significant annual changes in mean GSM compared with those who did not (0.94±6.88 vs -0.21±6.19 units/year, p=0.007).

CONCLUSIONS/INTERPRETATION

TIR and CV were significantly associated with changes in the tissue characteristics of the carotid artery wall.

TRIAL REGISTRATION

University Hospital Medical Information Network Clinical Trials Registry, number UMIN000032325.

Glucose variability: a new risk factor for cardiovascular disease

AIMS AND DATA SYNTHESIS

Glucose variability (GV) is increasingly considered an additional index of glycemic control. Growing evidence indicates that GV is associated with diabetic vascular complications, thus being a relevant point to address in diabetes management. GV can be measured using various parameters, but to date, a gold standard has not been identified. This underscores the need for further studies in this field also to identify the optimal treatment.

CONCLUSIONS

We reviewed the definition of GV, the pathogenetic mechanisms of atherosclerosis, and its relationship with diabetic complications.

Short-term Glycemic Variability and Its Association With Macrovascular and Microvascular Complications in Patients With Diabetes

The introduction of continuous glucose monitoring inaugurated a new era in clinical practice by shifting the characterization of glycemic control from HbA1c to novel metrics. The one that gained widespread attention over the past decades was glycemic variability (GV), which typically refers to peaks and nadirs of blood glucose measured over a given time interval. GV can be dichotomized into two main categories: short-term and long-term. Short-term GV reflects within-day and between-day glycemic oscillations, and its contribution to diabetic complications remains an enigma. In this review, we summarize the available data about short-term GV and its possible association with both microvascular and macrovascular complications, evaluating different pathogenic mechanisms and demonstrating nonpharmaceutical, as well as pharmaceutical, therapeutic interventions.

Divergent effect of blood glucose dysregulation on long-term clinical outcome in acute decompensated heart failure: A reappraisal in contemporary practice

BACKGROUND

The prognostic implication of elevated or decreased blood glucose (BG) level in acute decompensated heart failure (ADHF) has been still controversial. Indices of stress hyperglycemia, expressed by the ratio of BG and chronic BG control, has been reported to be associated with poor outcome in different disease population. We sought to assess BG at admission and %ΔBG, an index of BG deviation from estimated average BG calculated from glycated hemoglobin (HbA1c), on the long-term outcome in ADHF patients.

METHODS AND RESULTS

The West Tokyo Heart Failure (WET-HF) Registry is a prospective multicenter registry enrolling consecutive hospitalized ADHF patients. Among the patients (N = 3078, 77 [67-84] years, male 59%), BG at admission discriminated the long-term (1000 days) incidence of ADHF rehospitalization, but not cardiac death. BG at admission showed a U-shape relationship with the long-term incidence of ADHF rehospitalization after adjustment for covariates. Especially, in patients with HbA1c ≥ 6.5%, the lowest quartile showed the highest risk of ADHF rehospitalization. On the contrary, %ΔBG showed U-shape relationship with the long-term incidence of cardiac death after discharge, rather than ADHF rehospitalization after adjustment for covariates. In addition, elevated %ΔBG was associated with the long-term risk of sudden cardiac death (SCD) even after adjustment for covariates.

CONCLUSIONS

For ADHF patients, BG at admission and %ΔBG might be a simple, useful tool for predicting and stratifying long-term risk of cardiac events. Especially, elevated %ΔBG might be an important in predicting hard events such as cardiac death or SCD.

Glycaemic Control in Patients Undergoing Percutaneous Coronary Intervention: What Is the Role for the Novel Antidiabetic Agents? A Comprehensive Review of Basic Science and Clinical Data

Coronary artery disease (CAD) remains one of the most important causes of morbidity and mortality worldwide, and revascularization through percutaneous coronary interventions (PCI) significantly improves survival. In this setting, poor glycaemic control, regardless of diabetes, has been associated with increased incidence of peri-procedural and long-term complications and worse prognosis. Novel antidiabetic agents have represented a paradigm shift in managing patients with diabetes and cardiovascular diseases. However, limited data are reported so far in patients undergoing coronary stenting. This review intends to provide an overview of the biological mechanisms underlying hyperglycaemia-induced vascular damage and the contrasting actions of new antidiabetic drugs. We summarize existing evidence on the effects of these drugs in the setting of PCI, addressing pre-clinical and clinical studies and drug-drug interactions with antiplatelet agents, thus highlighting new opportunities for optimal long-term management of these patients.

How use of continuous glucose monitoring can address therapeutic inertia in primary care

A significant proportion of individuals with diabetes have suboptimal glycemic management. Studies have shown that persistent hyperglycemia significantly increases the risks for both acute and long-term microvascular and macrovascular complications of diabetes. A key contributor to suboptimal glycemic management is therapeutic inertia in which clinicians delay intensifying therapy when patients are not meeting their glycemic goals. During the past five years, an increasing number of individuals with type 1 diabetes (T1D) and insulin-treated type 2 diabetes (T2D) have adopted use of continuous glucose monitoring (CGM) for daily measurement of glucose levels. As demonstrated in numerous clinical trials and real-world observational studies, use of CGM improves glycated hemoglobin (HbA1c) and reduces the occurrence and severity of hypoglycemia. However, for primary care clinicians who are unfamiliar with using CGM, integrating this technology into clinical practice can be daunting. In this article, we discuss the benefits and rationale for using CGM compared with traditional blood glucose monitoring (BGM), review the evidence supporting the clinical value of CGM in patients with T1D and T2D, and describe how use of CGM in primary care can facilitate appropriate and more timely therapy adjustments.

Changes in glycemic variability, gastric emptying and vascular endothelial function after switching from twice-daily to once-weekly exenatide in patients with type 2 diabetes: a subpopulation analysis of the twin-exenatide study

BACKGROUND

We investigated the changes in blood glucose fluctuation, gastric emptying, and vascular endothelial function by switching from an exenatide twice-daily formulation (BID) to a once-weekly formulation (QW) since the evaluation of postprandial glucose excursion and glycemic variability (GV) by continuous glucose monitoring (CGM) after switching was lacking.

METHODS

Twenty-nine patients with type 2 diabetes treated with exenatide BID were included in this study and switched to exenatide QW for 24 weeks. GV assessed by CGM, gastric emptying (by ¹³ C-acetate breath test) and vascular endothelial function (by reactive hyperemia - peripheral arterial tonometry) were evaluated at baseline and 24 weeks after switching.

RESULTS

HbA1c decreased significantly from the baseline to week 24, while postprandial glucose levels after breakfast and dinner significantly increased (both P <0.05). However, the increases in GV indices were modest and not statistically significant at week 24. Vascular endothelial function was also not significantly changed after switching (P >0.05). Gastric emptying was significantly accelerated at week 24 (T_max 83.4 ± 12.1 min vs. 58.2 ± 16.4 min) (P <0.001) and correlated with increased postprandial glucose levels after breakfast and dinner (both P <0.05).

CONCLUSIONS

Despite the increase in postprandial glucose associated with accelerated gastric emptying after switching from exenatide BID to QW, change in GV was modest and no significant deterioration in vascular endothelial function was observed after switching. These results support the superiority of treatment with exenatide QW over exenatide BID in clinical practice; however, attention should be paid to the monitoring and management of postprandial glucose levels when selecting exenatide QW.

TRIAL REGISTRATION

Clinical trial registry number; UMIN000016390 and jRCTs031180320 . Approval date of Registry and the Registration: December 12, 2014.

Relationship between hemoglobin A1C and characteristics of plaque vulnerability in stable coronary disease: an optical coherence tomography study

Patients with diabetes mellitus are at increased risk of cardiovascular events. We aimed to analyze the impact of serum HbA1c levels on coronary plaque characteristics in stable coronary disease. Two hundred sixty-one patients who underwent optical coherence tomography (OCT) examination before elective percutaneous coronary intervention for a de novo obstructive lesions were included in this single-center retrospective analysis. Patients were divided into tertiles according to HbA1c level (tertile 1: HbA1c < 6.3%, tertile 2: 6.3 ≤ HbA1c < 7.8%, tertile 3: HbA1c ≥ 7.8%) and OCT findings were compared. Fibrous cap thickness (FCT) was significantly thinner in tertile 3 compared to tertile 1 and tertile 2 (103.9 ± 48.2 µm [tertile 1] vs. 107.5 ± 60.6 µm [tertile 2] vs. 86.2 ± 35.8 µm [tertile 3], p = 0.03). Higher prevalence of thin-cap fibroatheroma (TCFA) was observed in tertile 3 vs tertile 1 and tertile 2 (19.5% [tertile 1] vs. 19.5% [tertile 2] vs. 33.3% [tertile 3], p = 0.04). HbA1c inversely correlated with FCT (beta coefficient - 4.89, 95% confidence interval - 8.40 to - 1.39, p < 0.01). The logistic regression model revealed that the probability of having TCFA was positively associated with HbA1c with a small change in the range of low and medium HbA1c and a big change in the range of high HbA1c. Furthermore, minimal lumen area and reference lumen area were smaller in tertile 3. In patients with stable coronary disease, high serum HbA1c levels are associated with higher plaque burden and thinner FCT on OCT, while low and medium HbA1c levels result in similar plaque vulnerability.

Nonlinear association of 1,5-anhydroglucitol with the prevalence and severity of coronary artery disease in chinese patients undergoing coronary angiography

BACKGROUND

Postprandial hyperglycemia plays an important role in the pathogenesis of coronary artery disease (CAD). The aim of this study is to determine the associations of 1,5-Anhydroglucitol (1,5-AG), which reflects circulating glucose fluctuations, with the prevalence of CAD and CAD severity in coronary angiography defined Chinese patients.

METHODS

2970 Chinese patients undergoing coronary angiography were enrolled. Baseline demographics and medical history data was recorded. Serum 1,5-AG levels and biochemical parameters were measured. Baseline characteristics were compared across 1,5-AG categories in diabetes (DM) and non-DM groups. Logistic regression analysis was performed to evaluate the associations of 1,5-AG with the prevalence and severity of CAD.

RESULTS

Lower 1,5-AG was significantly associated with higher Gensini scores in both DM and non-DM groups. Logistic regression analysis demonstrated that the associations of low 1,5-AG with the prevalence of CAD, elevated Gensini score and severe CAD robustly dose-response increased from undiagnosed DM with 1,5-AG ≥ 14µg/mL to DM with 1,5-AG < 14µg/mL even after adjusting for fasting blood glucose (FBG) or Hemoglobin A1c (HbA_1c). The associations were more significant in persons with DM. Significant modification effect of DM on the relationship of 1,5-AG with elevated Gensini score was found. In addition, nonlinear relationship and threshold effects of 1,5-AG with CAD and severity were observed.

CONCLUSION

Low 1,5-AG is significantly and independently associated with CAD and CAD severity in Chinese patients undergoing coronary angiography. Measurement of 1,5-AG is useful to differentiate subjects with extensive glucose fluctuations and high CAD risks, especially in DM patients.

CLINICAL TRIAL REGISTRATION

ClinicalTrials.gov, identifier NCT03072797.

Association of visit-to-visit glycemic variability with risk of cardiovascular diseases in high-risk Japanese patients with type 2 diabetes: A subanalysis of the EMPATHY trial

AIMS/INTRODUCTION

Long-term glycemic variability is important for predicting diabetic complications, but evaluation in a Japanese population is lacking. The aim of this study was to explore the relationship between visit-to-visit glycemic variability (VVV) and cardiovascular diseases (CV) in Japanese patients with type 2 diabetes, using the prospective cohort of the EMPATHY trial.

MATERIALS AND METHODS

Among 4532 participants with at least three HbA1c measurements, VVV was defined using the coefficient of variation (CV-HbA1c). The outcomes were the composite cardiovascular endpoints, including cardiac, cerebral, renal, and vascular events. The odds ratios (ORs) for the development of outcomes were estimated by using logistic regression models.

RESULTS

During a median follow-up of 38 months, 190 subjects developed CV events. The risk of developing CV events increased significantly with increasing quintile of CV-HbA1c, after multivariable adjustment including the mean-HbA1c (OR for the fifth vs first quintile, 1.73; 95%CI, 1.03-2.91; P for trend test = 0.003). There was a stronger association between CV-HbA1c and CV events in patients with a mean-HbA1c of <7% compared with those with a mean-HbA1c of ≥7% (OR per 1 standard deviation, 1.51; 95%CI, 1.23-1.85 and 1.13; 95%CI, 0.98-1.29, respectively; P for interaction = 0.02).

CONCLUSIONS

Increases of VVV were associated with the risk of CV events in Japanese patients with type 2 diabetes independent of the mean-HbA1c. The long-term variability of HbA1c as well as the mean HbA1c might be an important glycemic indicator in the management of patients with type 2 diabetes, especially in those with a mean-HbA1c of <7%.

Risk stratification of cardiac arrhythmias and sudden cardiac death in type 2 diabetes mellitus patients receiving insulin therapy: A population-based cohort study

INTRODUCTION

Metabolic abnormalities may exacerbate the risk of adverse outcomes in patients with type 2 diabetes mellitus. The present study aims to assess the predictive value of HbA1c and lipid variability on the risks of sudden cardiac death (SCD) and incident atrial fibrillation (AF).

METHODS

The retrospective observational study consists of type 2 diabetic patients prescribed with insulin, who went to publicly funded clinics and hospitals in Hong Kong between January 1, 2009 and December 31, 2009. Variability in total cholesterol, low-density lipoprotein-cholesterol (LDL-C), high-density lipoprotein-cholesterol (HDL-C), triglyceride, and HbA1c were assessed through their SD and coefficient of variation. The primary outcomes were incident (1) ventricular tachycardia/ventricular fibrillation, actual or aborted SCD and (2) AF.

RESULTS

A total of 23 329 patients (mean ± SD age: 64 ± 14 years old; 51% male; mean HbA1c 8.6 ± 1.3%) were included. On multivariable analysis, HbA1c, total cholesterol, LDL-C and triglyceride variability were found to be predictors of SCD (p < .05).

CONCLUSION

HbA1c and lipid variability were predictive of SCD. Therefore, poor glucose control and variability in lipid parameters in diabetic patients are associated with aborted or actual SCD. These observations suggest the need to re-evaluate the extent of glycemic control required for outcome optimization.

The Role of Glycemic Variability in Cardiovascular Disorders

Diabetes mellitus (DM) is one of the most common and costly disorders that affect humans around the world. Recently, clinicians and scientists have focused their studies on the effects of glycemic variability (GV), which is especially associated with cardiovascular diseases. In healthy subjects, glycemia is a very stable parameter, while in poorly controlled DM patients, it oscillates greatly throughout the day and between days. Clinically, GV could be measured by different parameters, but there are no guidelines on standardized assessment. Nonetheless, DM patients with high GV experience worse cardiovascular disease outcomes. In vitro and in vivo studies showed that high GV causes several detrimental effects, such as increased oxidative stress, inflammation, and apoptosis linked to endothelial dysfunction. However, the evidence that treating GV is beneficial is still scanty. Clinical trials aiming to improve the diagnostic and prognostic accuracy of GV measurements correlated with cardiovascular outcomes are needed. The present review aims to evaluate the clinical link between high GV and cardiovascular diseases, taking into account the underlined biological mechanisms. A clear view of this challenge may be useful to standardize the clinical evaluation and to better identify treatments and strategies to counteract this DM aspect.

Impact of daily glucose fluctuations on cardiovascular outcomes after percutaneous coronary intervention for patients with stable coronary artery disease undergoing lipid-lowering therapy

AIMS/INTRODUCTION

Glucose fluctuation (GF) is a residual risk factor for coronary artery disease (CAD). We investigated whether GF influenced clinical outcomes and progression of coronary stenosis in stable CAD patients.

MATERIALS AND METHODS

In this prospective study, 101 consecutive lipid-controlled stable CAD patients underwent percutaneous coronary intervention were enrolled, and GF was expressed as the mean amplitude of glycemic excursion (MAGE) obtained by continuous glucose monitoring before the procedure was evaluated. At 9 months after enrollment, culprit and non-culprit (mild-to-moderate stenosis without ischemia) lesions were serially assessed by angiography. Cardiovascular events (CVE) consisting of cardiovascular death, non-fatal myocardial infarction or ischemia-driven revascularization during 2-year follow up, rapid progression in non-culprit lesions (defined as ≥10% luminal narrowing progression in lesions with stenosis ≥50%, ≥30% luminal narrowing progression in non-culprit lesions with stenosis <50% or normal segment, or progression to total occlusion) were evaluated.

RESULTS

CVE occurred in 25 patients, and MAGE was significantly higher in the CVE group (76.1 ± 24.8 mg/dL vs 59.3 ± 23.7 mg/dL; P = 0.003). Multivariate analysis showed that MAGE was an independent predictor of CVE (odds ratio 1.027, 95% confidence interval 1.008-1.047; P = 0.005). The optimal MAGE value to predict CVE was 70.7 mg/dL (area under the curve 0.687, 95% confidence interval 0.572-0.802; P = 0.005). Furthermore, MAGE was independently associated with rapid progression, and with the luminal narrowing progression in all non-culprit lesions (r = 0.400, P < 0.05).

CONCLUSIONS

Daily GF might influence future CVE in lipid-controlled stable CAD patients.

The impact of vildagliptin on the daily glucose profile and coronary plaque stability in impaired glucose tolerance patients with coronary artery disease: VOGUE-A multicenter randomized controlled trial

Background

The impact of reduction in glycemic excursion on coronary plaques remains unknown. This study aimed to elucidate whether a dipeptidyl peptidase 4 inhibitor could reduce the glycemic excursion and stabilize the coronary plaques compared with conventional management in coronary artery disease (CAD) patients with impaired glucose tolerance (IGT).

Methods

This was a multicenter, randomized controlled trial including CAD patients with IGT under lipid-lowering therapy receiving either vildagliptin (50 mg once a day) or no medication (control group) regarding glycemic treatment. The primary endpoint was changes in the minimum fibrous cap thickness and lipid arc in non-significant native coronary plaques detected by optical coherence tomography at 6 months after intervention. Glycemic variability expressed as the mean amplitude of glycemic excursion (MAGE) measured with a continuous glucose monitoring system was evaluated before and 6 months after intervention.

Results

A total of 20 participants with 47 lesions were allocated to either the vildagliptin group (10 participants, 22 lesions) or the control group (10 participants, 25 lesions). The adjusted difference of mean changes between the groups was − 18.8 mg/dl (95% confidence interval, − 30.8 to − 6.8) (p = 0.0064) for the MAGE (vildagliptin, − 20.1 ± 18.0 mg/dl vs. control, 2.6 ± 12.7 mg/dl), − 22.8° (− 40.6° to − 5.1°) (p = 0.0012) for the mean lipid arc (vildagliptin, − 9.0° ± 25.5° vs. control, 15.8° ± 16.8°), and 42.7 μm (15.3 to 70.1 μm) (p = 0.0022) for the minimum fibrous cap thickness (vildagliptin, 35.7 ± 50.8 μm vs. control, − 15.1 ± 25.2 μm).

Conclusions

Vildagliptin could reduce the MAGE at 6 months and may be associated with the decreased lipid arc and increased minimum FCT of the coronary plaques in CAD patients with IGT as compared with the control group. These findings may represent its potential stabilization effect on coronary plaques, which are characteristic in this patient subset.

Trial registration Registered in the UMIN clinical trial registry (UMIN000008620), Name of the registry: VOGUE trial, Date of registration: Aug 6, 2012, URL: https://upload.umin.ac.jp/cgi-open-bin/ctr/ctr_view.cgi?recptno=R000010058

Small Dense Low-Density Lipoprotein Cholesterol: A Residual Risk for Rapid Progression of Non-Culprit Coronary Lesion in Patients with Acute Coronary Syndrome

Aim: This study investigated whether the small dense low-density lipoprotein cholesterol (sd-LDL-c) level is associated with the rapid progression (RP) of non-culprit coronary artery lesions and cardiovascular events (CE) after acute coronary syndrome (ACS).

Methods: In 142 consecutive patients with ACS who underwent primary percutaneous coronary intervention for the culprit lesion, the sd-LDL-c level was measured using a direct homogeneous assay on admission for ACS and at the 10-month follow-up coronary angiography. RP was defined as a progression of any pre-existing coronary stenosis and/or stenosis development in the initially normal coronary artery. CEs were defined as cardiac death, myocardial infarction, stroke, or coronary revascularization.

Results: Patients were divided into two groups based on the presence ( n =29) or absence ( n =113) of RP after 10 months. The LDL-c and sd-LDL-c levels at baseline were equivalent in both the groups. However, the sd-LDL-c, triglyceride, remnant lipoprotein cholesterol (RL-c), and apoC3 levels at follow-up were significantly higher in the RP group than in the non-RP group. The optimal threshold values of sd-LDL-c, triglyceride, RL-c, and apoC3 for predicting RP according to receiver operating characteristics analysis were 20.9, 113, 5.5, and 9.7 mg/dL, respectively. Only the sd-LDL-c level (≥ 20.9 mg/dL) was significantly associated with incident CEs at 31±17 months (log-rank: 4.123, p =0.043).

Conclusions: The sd-LDL-c level on treatment was significantly associated with RP of non-culprit lesions, resulting in CEs in ACS patients. On-treatment sd-LDL-c is a residual risk and aggressive reduction of sd-LDL-c might be needed to prevent CEs.

High cardiovascular risk of patients with type 2 diabetes is only partially attributed to angiographic burden of atherosclerosis

BACKGROUND

Patients with type 2 diabetes (T2DM) are at high risk for cardiovascular events and present more severe coronary artery disease (CAD). The Gensini and COURAGE scores are established angiographic instruments to assess CAD severity, which may also predict future cardiovascular risk. However, it is unclear if these scores are able to depict the increased risk of patients with T2DM and stable CAD (T2DM-SAP).

METHODS

We performed quantitative coronary angiography and assessed the Gensini and COURAGE scores in 124 patients with T2DM-SAP. Angiographic data were compared to patients with stable angina without T2DM (Non-DM-SAP, n = 74), and to patients with acute coronary syndrome and T2DM (T2DM-ACS, n = 53).

RESULTS

T2DM-SAP patients had similar Gensini and COURAGE-scores compared to Non-DM-SAP-patients (Gensini: 14.44 ± 27.34 vs 11.49 ± 26.99, p = 0.465; COURAGE: 3.48 ± 4.49 vs 3.60 ± 4.72, p = 0.854). In contrast, T2DM-SAP patients had significantly lower Gensini (14.44 ± 27.34 vs 30.94 ± 48.74, p = 0.003) and lower COURAGE (3.48 ± 4.49 vs 5.30 ± 4.63, p = 0.016) scores compared to T2DM-ACS-patients.

CONCLUSION

Both the Gensini and the COURAGE score fail to predict the high cardiovascular risk of patients with T2DM-SAP. Therefore, these scores should be used with caution in the assessment of future risk of patients with T2DM. However, among T2DM-ACS patients, both scores are increased, reflecting the high cardiovascular risk in this patient population.

Relationship between daily and visit-to-visit glycemic variability in patients with type 2 diabetes

The aim of the study was to explore the relationship between daily glycemic variability (GV) and visit-to-visit glycemic variability (VVV) in patients with type 2 diabetes (T2DM). A total of 156 outpatients with T2DM who had undergone continuous glucose monitoring (CGM) for 5 days were included in this study. Indices of GV, i.e., standard deviation and coefficient of variation (CV) of glucose, mean amplitude of glycemic excursion (MAGE) and mean of the daily differences (MODD) were calculated from the CGM data. VVV was calculated as CV of HbA1c or glycated albumin (GA) from HbA1c or GA measured for 3 years. Relationships among clinical parameters, GV and VVV were evaluated. Age was positively, and BMI and C-peptide index were inversely correlated with GV such as CV glucose and MAGE, while BMI was positively correlated with VVV. Mean glucose rather than GV was correlated with VVV. In contrast, time in range (TIR, 70-180 mg/dL) was correlated with both mean HbA1c or GA and VVV. In conclusion, GV and VVV were differently correlated with clinical parameters and were hardly correlated with each other. TIR was correlated with both mean HbA1c and VVV, suggesting that efforts to achieve optimal TIR are practical strategies to reduce VVV in patients with T2DM.

Quantification of atherosclerotic plaque volume in coronary arteries by computed tomographic angiography in subjects with and without diabetes

Background

Diabetes mellitus (DM) is considered a cardiovascular risk factor. The aim of this study was to analyze the prevalence and volume of coronary artery plaque in patients with diabetes mellitus (DM) vs. those without DM.

Methods

This study recruited consecutive patients who underwent coronary computed tomography (CT) angiography (CCTA) between October 2016 and November 2017. Personal information including conventional cardiovascular risk factors was collected. Plaque phenotypes were automatically calculated for volume of different component. The volume of different plaque was compared between DM patients and those without DM.

Results

Among 6381 patients, 931 (14.59%) were diagnosed with DM. The prevalence of plaque in DM subjects was higher compared with nondiabetic group significantly (48.34% vs. 33.01%, χ² = 81.84, P < 0.001). DM was a significant risk factor for the prevalence of plaque in a multivariate model (odds ratio [OR] = 1.465, 95% CI: 1.258–1.706, P < 0.001). The volume of total plaque and any plaque subtypes in the DM subjects was greater than those in nondiabetic patients significantly (P < 0.001).

Conclusion

The coronary artery atherosclerotic plaques were significantly higher in diabetic patients than those in non-diabetic patients.

Efficacy of Zotarolimus-Eluting Stents in Treating Diabetic Coronary Lesions: An Optical Coherence Tomography Study

BACKGROUND

Diabetes mellitus (DM) plays an important role in restenosis and late in-stent thrombosis (ST). The current study using optical coherence tomography (OCT) aims to compare target lesion neointima in patients with or without diabetes after zotarolimus-eluting stent (ZES) treatment.

METHODS

OCT images of 90,212 struts and quantitative coronary angiography (QCA) in 62 patients (32 with DM and 30 without DM) with 69 de novo coronary lesions (34 DM and 35 non-DM) both after ZES implantation and 12 ± 1 month angiographic follow-up were recorded. Patient characteristics, lesion characteristics, clinical outcomes, and OCT findings including neointimal thickness, coverage, malapposition, and intimal morphology were analyzed.

RESULTS

Baseline patient characteristics and lesion characteristics data were similar between the two groups. Higher neointimal thickness (0.14 ± 0.09 mm vs. 0.09 ± 0.04 mm, p = 0.021), more neovascularization (3.03 ± 6.24 vs. 0.52 ± 1.87, p = 0.017) and higher incidence of layered signal pattern (12.19 ± 19.91% vs. 4.28 ± 9.02%, p = 0.049) were observed in diabetic lesions comparing with non-diabetic lesions. No differences were found in malapposition, uncovered percentage, and thrombus between the two groups (all p > 0.05). Occurrence of clinical adverse events was also similar during the follow-up period (p > 0.05).

CONCLUSION

Although more neointimal proliferation and more neovascularization were found in diabetic coronary lesions when compared with non-diabetic lesions, treatment with ZES showed similar stent malapposition rate at 1-year follow-up. The data indicated that ZES treatment could possibly be effective in treating diabetic coronary lesions.

TRIAL REGISTRATION

ClinicalTrials.gov identifier, NCT01747356.

Effects of Glucose Fluctuation Targeted Intervention on the Prognosis of Patients with Type 2 Diabetes following the First Episode of Cerebral Infarction

OBJECTIVE

The purpose of this study was to assess the effects of glucose fluctuation targeted intervention on neurologic function, independent living skills, and quality of life in type 2 diabetes patients following the first episode of cerebral infarction (CI).

METHODS

This was a randomized control trial. Following confirmed cerebral infarction, 75 patients with type 2 diabetes were randomized into 2 groups: control group (n = 37) with usual care, focused on hemoglobin A1c (HbA1c) control, targeting A1c < 7%, and intervention group (n = 37) with usual care, focused on hemoglobin A1c (HbA1c) control, targeting A1c < 7%, and intervention group (.

RESULTS

After 6 months, data from 63 patients were analyzed (30 in the control group, 33 in the intervention group). There was no difference (P > 0.05) in the reduction of A1c between the 2 groups, but the reductions of LAGE (P > 0.05) in the reduction of A1c between the 2 groups, but the reductions of LAGE (P > 0.05) in the reduction of A1c between the 2 groups, but the reductions of LAGE (P > 0.05) in the reduction of A1c between the 2 groups, but the reductions of LAGE (P > 0.05) in the reduction of A1c between the 2 groups, but the reductions of LAGE (P > 0.05) in the reduction of A1c between the 2 groups, but the reductions of LAGE (P > 0.05) in the reduction of A1c between the 2 groups, but the reductions of LAGE (P > 0.05) in the reduction of A1c between the 2 groups, but the reductions of LAGE (P > 0.05) in the reduction of A1c between the 2 groups, but the reductions of LAGE (.

CONCLUSION

Glucose fluctuation targeted intervention can improve nerve function for patients with T2DM following the first CI episode. This trial is registered with NCT03932084.

Association between Admission Hyperglycemia and Culprit Lesion Characteristics in Nondiabetic Patients with Acute Myocardial Infarction: An Intravascular Optical Coherence Tomography Study

BACKGROUND

Hyperglycemia is frequently observed in acute myocardial infarction (AMI). Diabetes mellitus (DM) patients and non-DM patients have different culprit lesion phenotypes and few data are available on non-DM patients with admission hyperglycemia. Therefore, we aimed to investigate the association between admission hyperglycemia and culprit lesion characteristics using optical coherence tomography (OCT) in AMI patients.

METHODS AND RESULTS

We consecutively enrolled 434 patients with AMI, and 277 patients were included in analysis: 65.7% (n = 182) non-DM patients and 34.3% (n = 95) DM patients. We measured acute blood glucose (ABG) and hemoglobin A_1c to calculate the acute-to-chronic glycemic ratio (A/C). Then, we grouped non-DM patients into tertiles of A/C. OCT-based culprit lesion characteristics were compared across A/C tertiles in non-DM patients and between DM and non-DM patients. Non-DM patients had fewer lipid-rich plaques (52.7% versus 68.4%, p = 0.012) and thin-cap fibroatheroma (TCFA) (19.8% versus 34.7%, p = 0.006) than DM patients but similar prevalence of plaque rupture (47.3% versus 56.8%, p = 0.130). Non-DM patients with the highest A/C tertile had the highest prevalence of plaque rupture (p _for trend = 0.002), lipid-rich plaque (p _for trend = 0.001), and TCFA (p _for trend = 0.003). A/C > 1.22 but not ABG > 140 mg/dl predicted a high prevalence of plaque rupture, lipid-rich plaque, and TCFA in non-DM patients.

CONCLUSIONS

In AMI patients without DM, admission hyperglycemia is associated with vulnerable culprit lesion characteristics, and A/C is a better predictor for vulnerable culprit plaque characteristics than ABG. These results call for a tailored evaluation and management of glucose metabolism in nondiabetic AMI patients. This trial is registered with NCT03593928.

Cardiovascular disease and 1,5-anhydro-d-glucitol

The serum 1,5-anhydro-d-glucitol (1,5-AG) level rapidly decreases concomitantly with urinary glucose excretion in hyperglycemia. 1,5-AG is a sensitive clinical marker of short-term glycemic control, postprandial hyperglycemia and glucose fluctuation. Increasing evidence about the relationship between cardiovascular disease (CVD) and glucose fluctuations have been published. In this review, we summarize the possibilities and limitations of 1,5-AG as a marker of CVD. Research showed that 1,5-AG level is associated with prevalence of CVD and is also a predictive value for cardiovascular (CV) events. Especially in a high risk population, the predictive value of 1,5-AG for CV events becomes more effective. Besides, 1,5-AG is an effective glycometabolic marker that complements HbA1c in terms of glucose fluctuation. Appropriate use of 1,5-AG might lead to improved prognosis for patients or decrease medical financial burden of the population through early detection of glucose disorder and quality glucose control.

The correlation between glucose fluctuation from self-monitored blood glucose and the major adverse cardiac events in diabetic patients with acute coronary syndrome during a 6-month follow-up by WeChat application

Background This study aimed to investigate the correlation between glucose fluctuation from self-monitored blood glucose (SMBG) and the major adverse cardiac events (MACE) in diabetic patients with acute coronary syndrome (ACS) during a 6-month follow-up period using the WeChat application. Methods From November 2016 to June 2017, 262 patients with ACS were discharged in a stable condition and completed a 6-month follow-up period. SMBG was recorded using the WeChat application. The patients were divided to a high glucose fluctuation group (H group; n=92) and a low glucose fluctuation group (L group; n=170). The 6-month incidence of MACE, lost-to-follow-up rate and satisfaction rate were measured through the WeChat follow-up. Results MACE occurred in 17.4% of patients in the H group and in 8.2% of patients in the L group (p=0.04). Multivariable analysis suggested that high glucose fluctuation conferred an 87% risk increment of MACE in the 6-month follow-up period (odds ratio: 2.1, 95% confidence interval 1.95-4.85; p=0.03). The lost-to-follow-up rate was lower and the satisfaction rate was higher in the patients using the WeChat application during follow-up than those of the regular outpatient follow-up during the same period (p<0.05). Conclusions The trial demonstrates that higher glucose fluctuation from SMBG after discharge was correlated with a higher incidence of MACE in diabetic patients with ACS. WeChat follow-up might have the potential to promote a good physician-patient relationship.

The fluctuation in sympathetic nerve activity around wake-up time was positively associated with not only morning but also daily glycemic variability in subjects with type 2 diabetes

AIMS

It is known that autonomic nerve activity (ANA) affects glucose metabolism by regulating the secretion of insulin and glucagon. Sympathetic nerve stimulation results in increased blood glucose levels. ANA also showed a circadian variation, and sympathetic nerve activity was minimal at night and began to rise at arousal. Therefore, a drastic alteration in ANA around wake-up would be associated with glycemic variability (GV) known risk factor for cardiovascular disease. We investigated the relation between ANA around wake-up and either morning or daily GV.

METHODS

We simultaneously performed Holter ECG and continuous glucose monitoring system in 41 patients with type 2 diabetes (T2D). ANA was assessed by heart rate variability (HRV) analysis. Delta (Δ) wake-up was defined as the difference between the maximum and minimum value during 1 h before and after wake-up time, before breakfast.

RESULTS

Δ of low frequency/high frequency (LF/HF) around wake-up time (Δ LF/HF _wake-up) was positively associated with Δ glucose _wake-up, standard deviation (SD) glucose _wake-up, the mean amplitude of glucose excursions (MAGE_24h), and SD glucose_24h after adjustment for age, sex, BMI, the duration of diabetes, and the prevalence of diabetic polyneuropathy (β = 0.47, p = 0.011, β = 0.48, p = 0.009, β = 0.54, p = 0.002 and β = 0.41, p = 0.0025, respectively). No association was found between Δ LF/HF_wake-up and either mean blood glucose for 24 h, or HbA1c as parameters of chronic hyperglycemia.

CONCLUSIONS

In T2D, the fluctuation in fasting sympathetic nerve activity around wake-up was positively associated with not only morning but also daily GV.

Glucose Variability and Coronary Artery Disease

Fasting blood glucose, postprandial blood glucose and glycated haemoglobin are considered three important indicators for diabetes treatment. There is increasing evidence that glucose variability has more detrimental effects on the coronary arteries than does chronic sustained hyperglycaemia. This overview summarises recent findings in the field of glucose variability and its possible relationship with coronary artery disease. Glucose variability may be a marker of increased progression of coronary disease and plaque vulnerability. It might be a potential new therapeutic target for secondary prevention of coronary artery disease. Future studies will focus on the early detection and control of glucose variability to improve the clinical outcomes in patients with coronary artery disease.

Visit-to-visit HbA1c variability is inversely related to baroreflex sensitivity independently of HbA1c value in type 2 diabetes

BACKGROUND

The relationship between long-term glycemic variability (GV) represented by visit-to-visit HbA1c variability and baroreflex sensitivity (BRS) in type 2 diabetes mellitus (T2DM) has not been clarified by previous literature. The present study is the first to examine the relationships between visit-to-visit HbA1c variability and BRS.

METHODS

This retrospective study initially analyzed data on 94 patients with T2DM. Visit-to-visit HbA1c variability was evaluated using the intrapersonal coefficient of variation (CV), standard deviation (SD), and adjusted SD of 8 or more serial measurements of HbA1c during a 2-year period. The BRS was analyzed using the sequence method. Short-term GV was assessed by measuring the glucose CV during 24-h continuous glucose monitoring (CGM). The primary objective was to determine if there was a relationship between visit-to-visit HbA1c variability (HbA1c CV) and BRS. Secondary objectives were to examine the relationship between other variables and BRS and the respective and combined effects of long-term GV (HbA1c CV) and short-term GV (CGM CV) on BRS.

RESULTS

A total of 57 patients (mean age 67.2 ± 7.7 years, mean HbA1c 7.3 ± 1.0%) who met this study's inclusion criteria were finally analyzed. In the univariate analysis, HbA1c CV (r = - 0.354, p = 0.007), HbA1c SD (r = - 0.384, p = 0.003), and adjusted HbA1c SD (r = - 0.391, p = 0.003) were significantly related to low levels of BRS. Multiple regression analysis showed that HbA1c CV, HbA1c SD, and adjusted HbA1c SD were inversely related to BRS. Furthermore, although the increase in either long-term GV (HbA1c CV) or short-term GV (CGM CV) as determined by 24-h CGM was inversely correlated with BRS, additional reductions in BRS were not shown in participants with both HbA1c CV and CGM CV values above the median.

CONCLUSIONS

Visit-to-visit HbA1c variability was inversely related to BRS independently of the mean HbA1c in patients with T2DM. Therefore, visit-to-visit HbA1c variability might be a marker of reduced BRS in T2DM.

Non-culprit plaque characteristics in acute coronary syndrome patients with raised hemoglobinA1c: an intravascular optical coherence tomography study

Background

Raised hemoglobinA1c (HbA1c) is an indicator of pre-diabetes, which is associated with increased risk of coronary artery disease. However, the detailed morphological characteristics of non-culprit plaques in acute coronary syndrome (ACS) patients remain largely unknown.

Methods

A total of 305 non-culprit plaques from 216 ACS patients were analyzed by intravascular optical coherence tomography. These patients were divided into three groups according to the serum glycosylated hemoglobin level: normal HbA1c (< 5.7%), pre-diabetes with raised HbA1c (5.7–6.4%) and diabetes mellitus (DM).

Results

Plaques in patients with raised HbA1c had a longer lipid length (17.0 ± 8.3 mm vs. 13.9 ± 7.2 mm, P = 0.004) and greater lipid index (2775.0 ± 1694.0 mm° vs. 1592.1 ± 981.2 mm°, P = 0.001) than those with normal HbA1c but were similar to DM. The prevalence of calcification in patients with raised HbA1c was significantly higher (38.7% vs. 26.3%, P = 0.048) than normal HbA1c but was similar to DM. The percentage of macrophage infiltration in the DM group was higher than that in the normal HbA1c group (20.5% vs. 7.4%, P = 0.005).

Conclusions

Compared to patients with normal HbA1c, the non-culprit plaques in ACS patients with raised HbA1c had more typical vulnerable features but were similar to DM.

Glycemic variability in continuous glucose monitoring is inversely associated with baroreflex sensitivity in type 2 diabetes: a preliminary report

Background

It is presently unclear whether glycemic variability (GV) is associated with baroreflex sensitivity (BRS), which is an early indicator of cardiovascular autonomic neuropathy. The present study is the first to examine the relationships between BRS and GV measured using continuous glucose monitoring (CGM).

Methods

This was a multicenter, prospective, open-label clinical trial. A total of 102 patients with type 2 diabetes were consecutively recruited for this study. GV was assessed by measuring the standard deviation (SD), glucose coefficient of variation (CV), and the mean amplitude of glycemic excursions (MAGE) during CGM. The BRS was analyzed from electrocardiogram and blood pressure recordings using the sequence method on the first day of hospitalization.

Results

A total of 94 patients (mean diabetes duration 9.7 ± 9.6 years, mean HbA1c 61.0 ± 16.8 mmol/mol [7.7 ± 1.5%]) were analyzed. In the univariate analysis, CGM-SD (r = − 0.375, p = 0.000), CGM-CV (r = − 0.386, p = 0.000), and MAGE (r = − 0.395, p = 0.000) were inversely related to BRS. In addition to GV, the level of BRS correlated with the coefficient of variation in the R–R intervals (CVR-R) (r = 0.520, p = 0.000), heart rate (HR) (r = − 0.310, p = 0.002), cardio-ankle vascular index (CAVI) (r = − 0.326, p = 0.001), age (r = − 0.519, p = 0.000), and estimated glomerular filtration rate (eGFR) (r = 0.276, p = 0.007). Multiple regression analysis showed that CGM-CV and MAGE were significantly related to a decrease in BRS. These findings remained after adjusting the BRS for age, sex, hypertension, dyslipidemia, HR, eGFR, CAVI, and CGM-mean glucose. Additionally, BRS was divided according to quartiles of the duration of diabetes (Q1–4). BRS decreased after a 2-year duration of diabetes independently of age and sex.

Conclusions

GV was inversely related to BRS independently of blood glucose levels in type 2 diabetic patients. Measurement of BRS may have the potential to predict CV events in consideration of GV.

Trial registration UMIN Clinical Trials Registry UMIN000025964, 28/02/2017

Electronic supplementary material

The online version of this article (10.1186/s12933-018-0683-2) contains supplementary material, which is available to authorized users.

Impact of CD14++CD16+ monocytes on coronary plaque vulnerability assessed by optical coherence tomography in coronary artery disease patients

BACKGROUND AND AIMS

This study examined the impact of CD14⁺⁺CD16⁺ monocytes on coronary plaque vulnerability, as assessed by optical coherence tomography (OCT), and investigated their association with daily glucose fluctuation. Although increased CD14⁺⁺CD16⁺ monocyte levels have been reported to increase cardiovascular events, their impact on coronary plaque vulnerability in coronary artery disease (CAD) patients with or without diabetes mellitus (DM) remains unclear.

METHODS

This prospective observational study included 50 consecutive patients with CAD, receiving lipid-lowering therapy and undergoing coronary angiography and OCT. Patients were divided into 3 tertiles according to the CD14⁺⁺CD16⁺ monocyte percentages assessed by flow cytometry. Standard OCT parameters were assessed for 97 angiographically intermediate lesions (diameter stenosis: 30-70%). Daily glucose fluctuation was analyzed by measuring the mean amplitude of glycemic excursion (MAGE).

RESULTS

CD14⁺⁺CD16⁺ monocytes negatively correlated with fibrous cap thickness (r = -0.508, p < 0.01). The presence of thin-cap fibroatheroma (TCFA) was increased stepwise according to the tertile of CD14⁺⁺CD16⁺ monocytes (0 [tertile 1] vs. 5 [tertile 2] vs. 10 [tertile 3], p < 0.01). CD14⁺⁺CD16⁺ monocytes were a significant determinant of TCFA (OR 1.279, p = 0.001). In non-DM patients, a significant relationship was found between CD14⁺⁺CD16⁺ monocytes and MAGE (r = 0.477, p = 0.018).

CONCLUSIONS

CD14⁺⁺CD16⁺ monocytes were associated with coronary plaque vulnerability in CAD patients with well-regulated lipid levels both in DM and non-DM patients. Cross-talk between glucose fluctuation and CD14⁺⁺CD16⁺ monocytes may enhance plaque vulnerability, particularly in non-DM patients. CD14⁺⁺CD16⁺ monocytes could be a possible therapeutic target for coronary plaque stabilization.

Type 2 diabetes mellitus is associated with a lower fibrous cap thickness but has no impact on calcification morphology: an intracoronary optical coherence tomography study

Background

Patients with type 2 diabetes (T2DM) are at high risk for cardiovascular events, which usually arise from the rupture of a vulnerable coronary plaque. The minimal fibrous cap thickness (FCT) overlying a necrotic lipid core is an established predictor for plaque rupture. Recently, coronary calcification has emerged as a relevant feature of plaque vulnerability. However, the impact of T2DM on these morphological plaque parameters is largely unexplored. Therefore, this study aimed to compare differences of coronary plaque morphology in patients with and without T2DM with a particular focus on coronary calcification.

Methods

In 91 patients (T2DM = 56, non-T2DM = 35) with 105 coronary de novo lesions (T2DM = 56, non-T2DM = 49) plaque morphology and calcification were analyzed using optical coherence tomography (OCT) prior to coronary intervention.

Results

Patients with T2DM had a lower minimal FCT (80.4 ± 27.0 µm vs. 106.8 ± 27.8 µm, p < 0.001) and a higher percent area stenosis (77.9 ± 8.1% vs. 71.7 ± 11.2%, p = 0.001) compared to non-diabetic subjects. However, patients with and without T2DM had a similar total number of calcifications (4.0 ± 2.6 vs. 4.2 ± 3.1, p = ns) and no significant difference was detected in the number of micro- (0.34 ± 0.79 vs. 0.31 ± 0.71), spotty (2.11 ± 1.77 vs. 2.37 ± 1.89) or macro-calcifications (1.55 ± 1.13 vs. 1.53 ± 0.71, all p = ns). The mean calcium arc (82.3 ± 44.8° vs. 73.7 ± 31.6), the mean thickness of calcification (0.54 ± 0.13 mm vs. 0.51 ± 0.15 mm), the mean calcified area (0.99 ± 0.72 mm² vs. 0.78 ± 0.49 mm²), the mean depth of calcification (172 ± 192 μm vs. 160 ± 76 μm) and the cap thickness overlying the calcification (50 ± 71 μm vs. 62 ± 61 μm) did not differ between the diabetic and non-diabetic groups (all p = ns).

Conclusion

T2DM has an impact on the minimal FCT of the coronary target lesion, but not on localization, size, shape or extent of calcification. Thus, the minimal FCT overlying the necrotic lipid core but not calcification is likely to contribute to the increased plaque vulnerability observed in patients with T2DM.

Impact of CD14++CD16+ monocytes on plaque vulnerability in diabetic and non-diabetic patients with asymptomatic coronary artery disease: a cross-sectional study

Background

Previously, we have reported that daily glucose fluctuations could affect coronary plaque vulnerability, but the underlying mechanisms remained unclear. This study sought to investigate the impact of CD14⁺⁺CD16⁺ monocytes on plaque vulnerability, as assessed by virtual histology intravascular ultrasound (VH-IVUS), as well as their relationship to fluctuating glucose levels in patients with asymptomatic coronary artery disease (CAD).

Methods

Fifty-one patients with asymptomatic CAD, who were undergoing lipid-lowering therapy and underwent VH-IVUS evaluation for angiographically mild to moderate lesions, were enrolled in the study. Standard VH-IVUS parameters, including the percentage volume of the necrotic core (%NC) within the plaque and the presence of a virtual histology thin-cap fibroatheroma (VH-TCFA), were then evaluated. Additionally, monocyte subsets were assessed by flow cytometry, and daily glucose fluctuations were analyzed by measuring the mean amplitude of glycemic excursion (MAGE).

Results

Among 82 plaques from 22 diabetes mellitus (DM) patients and 29 non-DM patients, 15 VH-TCFAs were identified. CD14⁺⁺CD16⁺ monocyte counts significantly correlated with both  %NC and the presence of VH-TCFA (%NC: r = 0.339, p = 0.002; VH-TCFA: p = 0.003). Multivariate logistic regression analysis revealed that CD14⁺⁺CD16⁺ monocyte counts were independently associated with VH-TCFA (odds ratio = 1.029, p = 0.004). Furthermore, CD14⁺⁺CD16⁺ monocyte counts were significantly correlated with the MAGE score in the non-DM patients (r = 0.544, p = 0.005).

Conclusions

CD14⁺⁺CD16⁺ monocyte levels are associated with coronary plaque vulnerability and can serve as a biomarker for VH-TCFA in patients with CAD undergoing lipid-lowering therapy. In patients without DM, glucose fluctuations may alter the balance of monocyte subsets.

Trial registration UMIN Registry number: UMIN000021228

Electronic supplementary material

The online version of this article (doi:10.1186/s12933-017-0577-8) contains supplementary material, which is available to authorized users.

Plaque Characteristics in Coronary Artery Disease Patients with Impaired Glucose Tolerance

BACKGROUND

Impaired glucose tolerance (IGT) patients are known to have a high risk of cardiovascular events and their prognosis has been reported to be poor. The present study aimed to compare coronary plaque characteristics among coronary artery disease (CAD) patients with normal glucose tolerance (NGT), those with IGT, and those with diabetes mellitus (DM) by using optical coherence tomography (OCT).

METHODS

The present study included 101 coronary artery disease patients (mean age, 67.9 ± 10.4 years; 82.4% male). OCT was performed for target and non-target vessels during percutaneous coronary intervention. The patients were divided into the following 3 groups: the NGT, IGT, and DM groups.

RESULTS

A total of 136 non-target residual plaques were found in 101 patients (27, 30, and 44 in the NGT, IGT, and DM groups, respectively). The size of the lipid core expressed as the mean angle of the lipid arc was significantly greater in the IGT and DM groups than in the NGT group (163.0 ± 58.7°, 170.1 ± 59.3°, and 130.9 ± 37.7°, respectively, P < 0.05). The fibrous cap covering the lipid core was significantly thinner in the IGT group than in the NGT group (77.0 ± 23.4 μm vs. 105.6 ± 47.0 μm, P = 0.040).

CONCLUSION

The coronary plaques in CAD patients are more vulnerable when having IGT compared to those with NGT, and similar to those with DM. This finding may explain the high risk of cardiovascular events in CAD patients with IGT.

Impact of serum 1,5-anhydro-d-glucitol level on prediction of major adverse cardiac and cerebrovascular events in non-diabetic patients without coronary artery disease

BACKGROUND AND AIMS

Increasing evidence has demonstrated that postprandial hyperglycemia and fluctuation of glucose level affect cardiovascular events. The serum 1,5-anhydro-d-glucitol (1,5-AG) level rapidly decreases concomitantly with urinary glucose excretion in hyperglycemia and is a useful clinical marker of short-term glycemic status. However, there is few established evidence regarding the predictive value of 1,5-AG for cardiovascular events in individuals without diabetes mellitus (DM). The aim of this study is 1) to prove predictive value of 1,5-AG for cardiovascular events in high risk population, and 2) the predictive value is true of even in non-diabetic population.

METHODS

Serum 1,5-AG values and coronary angiograms of 889 patients were evaluated. The study patients were divided into two groups (1,5-AG<10.0 μg/ml-group and 1,5-AG≥10.0 μg/ml-group) by their measured 1,5-AG values. They were followed-up and information regarding major adverse cardiac and cerebrovascular events (MACCE) was collected. MACCE consists of all causes of death, stroke, non-fatal myocardial infarction and cardiovascular hospitalization.

RESULTS

During the follow-up period (757 ± 357days), 216 patients presented with MACCE. In all patients, the 1,5-AG <10.0 μg/ml -group demonstrated significantly higher risk of MACCE (adjusted hazard ratio 1.63). Even in non-DM patients without coronary artery disease, the 1,5-AG <10.0 μg/m-group showed significantly higher risk of MACCE (adjusted hazard ratio 2.34). Similar results were found even if the events were limited to: all cause death, non-fatal myocardial infarction and stroke (adjusted hazard ratio 4.07) or all cause death (adjusted hazard ratio 3.54).

CONCLUSIONS

Serum 1,5-AG value predicts MACCE even in non-DM patients without coronary artery disease.

Stabilization of high-risk plaques

The prevalence of atherosclerotic cardiovascular diseases (ASCVDs) is increasing globally and they have become the leading cause of death in most countries. Numerous experimental and clinical studies have been conducted to identify major risk factors and effective control strategies for ASCVDs. The development of imaging modalities with the ability to determine the plaque composition enables us to further identify high-risk plaque and evaluate the effectiveness of different treatment strategies. While intensive lipid-lowering by statins can stabilize or even regress plaque by various mechanisms, such as the reduction of lipid accumulation in a necrotic lipid core, the reduction of inflammation, and improvement of endothelial function, there are still considerable residual risks that need to be understood. We reviewed important findings regarding plaque vulnerability and some encouraging emerging approaches for plaque stabilization.

Acute blood glucose fluctuation enhances rat aorta endothelial cell apoptosis, oxidative stress and pro-inflammatory cytokine expression in vivo

Background

Complications of diabetes mellitus (DM) are related not only to elevated plasma glucose, but also plasma glucose fluctuations. However, the specific mechanism underlying the role of plasma glucose fluctuation in the pathogenesis of DM complications remains poorly understood. In the present study, the influence of acute fluctuant hyperglycemia and persistent hyperglycemia on vascular endothelial cell apoptosis, function, oxidative stress and inflammation was examined in vivo.

Methods

Rats were assigned to three different groups (n = 10/group) that received 48-h infusions of saline (SAL group), continuous 50 % glucose (constant high glucose group [CHG]), or intermittent 50 % glucose (acute blood glucose fluctuation group [AFG]). Plasma 8-isoprostaglandin, interleukin-6 (IL-6), tumor necrosis factor-α (TNF-α) and intercellular adhesion molecule-1 (ICAM-1) levels were quantified by using enzyme-linked immunosorbent assay (ELISA) commercial kits. Plasma insulin levels were measured by radioimmunoassays (RIAs) using kits. The aortic segment was collected. The levels of malondialdehyde (MDA) and activity of glutathione peroxidase (GSH-PX) were measured in endothelial homogenates prepared from endothelial cells harvested from the aorta using colorimetric kits. Apoptosis of vascular endothelial cells was determined with terminal deoxynucleotidyl transferase dUTP nick end labeling (TUNEL). Endothelial dysfunction was assessed by isometric tension recording to evaluate the endothelial function. The expression of B cell lymphoma-2 (Bcl-2), Bcl-2 Associated X protein (Bax), pro caspase-3, caspase-3 p17, 3-nitrotyrosine (3-NT) and p47phox protein in rat aortic endothelial cells were tested with Western blot analysis. Endothelial cells reactive oxygen species (ROS) formation was determined using dihydroethidium-dependent fluorescence microtopography in aortic cryo-sections. Expression of IL-6, TNF-α and ICAM-1 mRNAs in vascular endothelial cells were determined by real-time quantitative PCR.

Results

Endothelial cells apoptosis and dysfunction were observed significantly in the aortas of the AFG group (P < 0.05). The AFG had reduced Bcl-2 and pro caspase-3 levels and enhanced Bax mitochondrial translocation and caspase-3 p17 protein levels in comparison with the CHG group (P < 0.05). Both AFG and CHG induced β-cell dysfunction and insulin resistance (P < 0.05). AFG increased MDA and 8-isoprostaglandin levels in plasma, oxidative stress in vascular endothelial cells, and inflammatory cytokines in plasma and vascular endothelial cells (P < 0.05).

Conclusion

Acute glucose fluctuation may cause significant oxidative stress and inflammation in endothelial cells, increase the adhesion of monocytes to endothelial cells, and elevate endothelial cell apoptosis, resulting in severe cardiovascular injury.

Effects of daily glucose fluctuations on the healing response to everolimus-eluting stent implantation as assessed using continuous glucose monitoring and optical coherence tomography

Background

Several studies have revealed that glucose fluctuations provoke oxidative stress that leads to endothelial cell dysfunction, progression of coronary atherosclerosis, and plaque vulnerability. However, little is known regarding their effect on neointimal growth after stenting in patients with coronary artery disease (CAD). We aimed to investigate the effects of glucose fluctuations on neointimal growth after everolimus-eluting stent (EES) implantation.

Methods

This study examined 50 patients who underwent a 9-month follow-up using optical coherence tomography (OCT) after EES implantation. Glucose fluctuation was expressed as the mean amplitude of glycemic excursion (MAGE), and was determined via continuous glucose monitoring before stenting. At the OCT follow-up, we evaluated the percentage of uncovered struts and three-dimensional uniformity of neointimal distribution by calculating the mean neointimal thickness (NIT) within 360 equally-spaced radial sectors for every 1-mm cross-sectional OCT analysis, and assessed the incidence of major adverse cardiovascular events (MACE).

Results

We evaluated 60 lesions in 50 patients. Linear mixed effect models were used to explore the influence of different variables on variability in NIT and the percentage of uncovered struts and to adjust for covariates. Univariate analysis showed that MAGE was most strongly correlated with the previously mentioned OCT measurements (coefficient β ± standard error = 0.267 ± 0.073 and 0.016 ± 0.003, t = 3.668 and 6.092, both P < 0.001, respectively). In multivariate analysis, MAGE had the strongest effect on variability in NIT (coefficient β ± standard error = 0.239 ± 0.093, P = 0.014) and the percentage of uncovered struts (coefficient β ± standard error = 0.019 ± 0.004, P < 0.001). Five lesions in four patients required target lesion revascularization (10.0 %) at a mean duration of 9 months after EES implantation. Compared to non-MACE cases, cases of MACE exhibited a significantly higher MAGE (99 vs. 68; P = 0.004), maximum NIT (580 vs. 330 µm; P = 0.002), and variability in NIT (100 vs. 65; P = 0.007), although there was no significant difference in these groups’ HbA1c levels.

Conclusions

Glucose fluctuation may affect vessel healing after EES implantation in patients with CAD who are receiving lipid-lowering therapy. Therefore, glucose fluctuations may be an important target for secondary prevention after coronary stenting, which is independent of dyslipidemia control.

Oscillating glucose induces microRNA-185 and impairs an efficient antioxidant response in human endothelial cells

BACKGROUND

Intracellular antioxidant response to high glucose is mediated by Cu/Mn-superoxide dismutases (SOD-1/SOD-2), catalase (CAT) and glutathione peroxidases (GPx), particularly glutathione peroxidase-1 (GPx-1). Although oscillating glucose can induce a more deleterious effect than high glucose on endothelial cells, the mechanism by which oscillating glucose exerts its dangerous effects is incompletely understood; however, the involvement of oxidative damage has been generally accepted. In this study we sought to determine whether oscillating glucose differentially modulates antioxidant response, and to elucidate the potential regulatory mechanisms exerted by the microRNA-185 (miR-185).

METHODS

Human endothelial cells were exposed for 1 week to constant and oscillating high glucose. SOD-1, SOD-2, CAT and GPx-1, as well as two markers of oxidative stress [8-hydroxy-2'-deoxyguanosine (8-OHdG) and the phosphorylated form of H2AX (γ-H2AX)] were measured at the end of the experiment. Intracellular miR-185 was measured and loss-of function assays were performed in HUVEC. Bioinformatic tool was used to predict the link between miR-185 on 3'UTR of GPx-1 gene. Luciferase assay was performed to confirm the binding on HUVEC.

RESULTS

After exposure to constant high glucose SOD-1 and GPx-1 increased, while in oscillating glucose SOD-1 increased and GPx-1 did not. SOD-2 and CAT remained unchanged under both conditions. A critical involvement of oscillating glucose-induced miR-185 in the dysregulation of endogenous GPx-1 was found. Computational analyses predict GPx-1 as miR-185's target. HUVEC cultures were used to confirm glucose's causal role on the expression of miR-185, its target mRNA and protein and finally the activation of antioxidant response. In vitro luciferase assays confirmed computational predictions targeting of miR-185 on 3'-UTR of GPx-1 mRNA. Knockdown of miR-185, using anti-miR-185 inhibitor, was accompanied by a significant upregulation of GPx-1 in oscillating glucose. 8-OHdG and γ-H2AX increased more in oscillating glucose than in constant high glucose.

CONCLUSIONS

Glucose oscillations may exert more deleterious effects on the endothelium than high glucose, likely due to an impaired response of GPx-1, coupled by the upregulation of miR-185.

Effects of analogue insulin in multiple daily injection therapy of type 2 diabetes on postprandial glucose control and cardiac function compared to human insulin: a randomized controlled long-term study

Background

The prevention of cardiovascular disease, including diastolic cardiac dysfunction with its high prevalence and ominous prognosis, is a therapeutic challenge for patients with type 2 diabetes. Both short and long-acting insulin analogues (AI) have been shown to reduce glucose variability and provide potential benefit for cardiovascular disease although the effects on cardiac function have not yet been evaluated. This long-term, prospective, randomized controlled trial in patients with type 2 diabetes (T2D) tested the hypothesis that a multiple daily injection regimen (MDI) with AI improves postmeal glucose excursions in comparison to human insulin (HI) and that the effects of AI improve diastolic cardiac function.

Methods

For 36 months, MDI treatment in 109 T2D patients was adapted every 3 months (targets: fasting glucose ≤ 110 mg/dl, postmeal glucose ≤ 150 mg/dl) in both groups: AI (insulin detemir and insulin aspart, n = 61) and HI (NPH-insulin and regular HI, n = 48). Diastolic cardiac function (myocardial velocity E’ using tissue Doppler imaging and the mitral inflow ratio E/A) and vascular function were assessed before and 2 h after a standardized breakfast (48 g carbohydrates). At baseline, both groups were comparable with regards to demographic, cardiac and metabolic data. Analysis of data included traditional statistics as well as the use of a multiple imputation technique shown in brackets [ ].

Results

At 36 months, the primary endpoint, postmeal glucose, decreased by 20 ± 62 mg/dl, p = 0.038 [p = 0.021] with AI and increased insignificantly with HI (inter-group p = 0.032 [p = 0.047]) to postmeal glucose levels of 161 ± 39 with AI vs. 195 ± 54 mg/dl with HI (inter-group p = 0.002 [p = 0.010]) whereas the levels of fasting glucose and HbA1c were comparable. With AI, postmeal E’ improved by 0.6 ± 1.4 cm/s, p = 0.009 [p = 0.002] and fasting E’ by 0.4 ± 1.4 cm/s, p = 0.069 [p = 0.013], however, E’ remained unchanged with HI. These changes were consistent with those of the traditional parameter E/A.

Conclusions

MDI with AI results in better postmeal glucose control compared to HI. The treatment with AI is associated with improved diastolic cardiac function.

ClinicalTrials.gov (NTC00747409)