Rapid 'glycaemic swings' induce nitrosative stress, activate poly(ADP-ribose) polymerase and impair endothelial function in a rat model of diabetes mellitus

Current landscape and comprehensive management of glycemic variability in diabetic retinopathy

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

PAR level mediates the link between ROS and inflammatory response in patients with type 2 diabetes mellitus

BACKGROUND

Type 2 diabetes mellitus (T2DM) is characterized by disrupted glucose homeostasis and metabolic abnormalities, with oxidative stress and inflammation playing pivotal roles in its pathophysiology. Poly(ADP-ribosyl)ation (PARylation) is a post-translational process involving the addition of ADP-ribose polymers (PAR) to target proteins. While preclinical studies have implicated PARylation in the interplay between oxidative stress and inflammation in T2DM, direct clinical evidence in humans remains limited. This study investigates the relationship between oxidative stress, PARylation, and inflammatory response in T2DM patients.

METHODS

This cross-sectional investigation involved 61 T2DM patients and 48 controls. PAR levels were determined in peripheral blood cells (PBMC) by ELISA-based methodologies. Oxidative stress was assessed in plasma and PBMC. In plasma, we monitored reactive oxygen metabolites (d-ROMs) and ferric-reducing antioxidant power. In PBMC, we measured the expression of antioxidant enzymes SOD1, GPX1 and CAT by qPCR. Further, we evaluated the expression of inflammatory mediators such as IL6, TNF-α, CD68 and MCP1 by qPCR in PBMC.

RESULTS

T2DM patients exhibited elevated PAR levels in PBMC and increased d-ROMs in plasma. Positive associations were found between PAR levels and d-ROMs, suggesting a link between oxidative stress and altered PAR metabolism. Mediation analysis revealed that d-ROMs mediate the association between HbA1c levels and PAR, indicating oxidative stress as a potential driver of increased PARylation in T2DM. Furthermore, elevated PAR levels were found to be associated with increased expression of pro-inflammatory cytokines IL6 and TNF-α in the PBMC of T2DM patients.

CONCLUSIONS

This study highlights that hyperactivation of PARylation is associated with poor glycemic control and the resultant oxidative stress in T2DM. The increase of PAR levels is correlated with the upregulation of key mediators of the inflammatory response. Further research is warranted to validate these findings and explore their clinical implications.

The impact of the stress hyperglycemia ratio on the risk of contrast-associated acute kidney injury in patients undergoing coronary angiography: a large real-world cohort study

BACKGROUND

Contrast-associated acute kidney injury (CA-AKI) is an important complication in the perioperative period of coronary angiography (CAG). Dysglycemia is closely associated with the occurrence of CA-AKI. However, the association between stress hyperglycemia and CA-AKI in patients undergoing CAG remains unclear. The study aims to investigate the association of the stress hyperglycemia ratio (SHR) and CA-AKI under CAG in a large real-world cohort.

METHODS

This was a retrospective observational study, and patients undergoing CAG were enrolled. SHR is calculated by dividing the random blood glucose with the estimated average glucose derived from the glycosylated hemoglobin (HbA1c), and subjects were divided into five groups according to SHR. The outcome was CA-AKI defined as an increase in serum creatinine of ≥ 0.3 mg/dL (26.5 μmol/L) or 1.5-fold higher than normal levels in 48 h. The association was assessed with logistic regression and restricted cubic spline analysis.

RESULTS

In 19,965 participants (men: 73.3%, mean age: 63.1 ± 10.8 years) undergoing CAG, a total of 1,621 CA-AKI cases occurred. There were reverse J-shaped associations between the SHR and CA-AKI after adjustment for other confounding factors. Moreover, SHR improved the predictive effectiveness of the traditional Mehran score (AUC 0.65 vs 0.63, P < 0.001), a predictive model of CA-AKI in patients undergoing percutaneous coronary intervention.

CONCLUSIONS

There were reverse J-shaped associations of SHR with CA-AKI risk among patients undergoing CAG, and the assessment of SHR before CAG may assist clinicians in identifying patients at higher risk of CA-AKI.

Association between glycemia risk index and arterial stiffness in type 2 diabetes

AIM

This study aims to investigate the association of glycemia risk index (GRI), a novel composite metric derived from continuous glucose monitoring (CGM), with arterial stiffness in patients with type 2 diabetes.

MATERIALS AND METHODS

A total of 342 adults with type 2 diabetes were enrolled between April and June 2023 from 11 communities in Shanghai, China. Medical examinations, including measurements of anthropometric parameters, blood pressure, and venous blood samples were conducted. Brachial-ankle pulse wave velocity (baPWV) was examined to evaluate arterial stiffness. All the participants underwent a 14 day CGM recording and GRI was calculated from the CGM data.

RESULTS

The mean age was 70.3 ± 6.8 years, and 162 (47.4%) were male. Participants with a higher baPWV had significantly higher levels of GRI and hyperglycemia component (both P for trend < 0.05). Linear regression revealed the significant positive linear associations of the GRI with baPWV in unadjusted or adjusted models (All P < 0.05). In the multivariable logistic analysis, each increase in the GRI quartile was associated with a 1.30-fold (95% CI 1.01-1.68, P for trend < 0.05) higher prevalence of increased arterial stiffness after adjustment for age, sex, BMI, diabetes duration, current smoking status, blood pressure, and lipid profile. Subgroup analyses showed that the association between the GRI quartiles and increased arterial stiffness was stronger among participants with a diabetes duration ≥15 years (P for interaction = 0.014).

CONCLUSION

Glycemia risk index assessed by continuous glucose monitoring is associated with increased arterial stiffness in type 2 diabetes.

Short-term glucose variability as a determinant of the healing rate of diabetic foot ulcer: A retrospective study

BACKGROUND

The aim of this study was to describe the clinical characteristics of people with diabetic foot ulcer (DFU) according to glucose variability (GV) and to investigate the relationship between GV and DFU outcome in a population with type 2 diabetes (T2D) and DFU.

METHODS

This is a retrospective study of 300 individuals aged 64.3 years (181 males) treated for DFU in a tertiary-care center with a regular follow-up for 6 months. Laboratory measurements and clinical assessments were collected at baseline. According to the coefficient of variation (CV) cut-off (≥36%), people were divided into two groups (low and high GV).

RESULTS

Compared with low GV group (n = 245), high GV group (n = 55) had significant longer duration of diabetes [low vs high GV, mean ± Standard Deviation (SD), 17.8 ± 11.8 vs 22.4 ± 10.8, P = 0.012], higher levels of glycated haemoglobin [median (IQR), 7.4 (6.6, 8.8) vs 8.2 (7.0, 9.6), P = 0.010] and urinary albumin excretion [25.2 (11.9, 77.0) vs 48.0 (23.2, 106.0), P = 0.031]. Moreover, 10 days self-monitoring of blood glucose-derived glycemic metrics were significantly different between groups. No differences among clinical features were found. The multiple logistic regression analysis identified CV and SD as negative predictors of healing.

CONCLUSIONS

In a population of people with T2D and DFU treated in a tertiary-care center, individuals with high GV had a 3-fold higher risk of healing failure, as compared with those with low GV. CV and SD were related to poor healing within 6 months follow-up.

Glycated hemoglobin variability and the risk of cardiovascular events in patients with prediabetes and type 2 diabetes mellitus: A post-hoc analysis of a prospective and multicenter study

AIMS/INTRODUCTION

High glycated hemoglobin (HbA1c) variability has been reported to be linked with cardiovascular events in type 2 diabetes patients. Only a few studies have been carried out on Asian patients. This study aimed to investigate the association of prediabetes and type 2 diabetes in Asian patients by performing a post-hoc analysis of a multicenter, prospective, observational study.

MATERIALS AND METHODS

Data for prediabetes and type 2 diabetes patients were retrieved from a multicenter national registry entitled "CORE-Thailand study." The primary outcome was 4P-MACE (major adverse cardiovascular events, including non-fatal myocardial infarction, heart failure hospitalization, non-fatal stroke and all-cause death). Patients were stratified according to quartiles of HbA1c standard deviation. The Cox proportional hazards regression model was used to estimate the association of HbA1c variability with incident cardiovascular disease.

RESULTS

A total of 3,811 patients with prediabetes and type 2 diabetes were included. The median follow-up duration was 54 months. In the fully adjusted model, the highest quartile of HbA1c variability showed a statistically significant association with 4P-MACE (hazard ratio [HR] 2.77, 95% confidence interval [CI] 1.77-4.35), fatal and non-fatal myocardial infarction (HR 6.91, 95% CI 1.90-25.12), hospitalization for heart failure (HR 3.34, 95% CI 1.20-9.26) and all-cause death (HR 3.10, 95% CI 1.72-5.57). All these outcomes were statistically significantly different among four quartiles of HbA1c (log-rank P-value <0.05). Fatal and non-fatal stroke showed no statistically significant association with high HbA1c variability.

CONCLUSION

High HbA1c variability in the highest quartile showed a statistically significant association with multiple adverse cardiovascular events in an Asian population. Minimizing HbA1c fluctuation during long-term follow up should be another important objective for type 2 diabetes patients.

Association of cumulative blood glucose load with cardiovascular risk and all-cause mortality

BACKGROUND

Incorporation both the magnitude and duration of exposure to elevated fasting blood glucose (FBG) into a single risk parameter (cumulative FBG load) for future diseases is intuitively appealing, although a data-based demonstration of the utility of this metric is not available. This study aimed to investigate the associations with cumulative FBG load with the risk of cardiovascular diseases (CVD) and all-cause mortality in the general population.

METHODS

This prospective cohort study included 41,728 participants who were free of CVD and underwent four health examinations from 2006 to 2012. Cumulative FBG load during 2006-2012 was calculated as the area under curve for FBG values ≥ 5.6 mmol/L divided by the total area curve. We also compared the predicting value cumulative FBG load with other FBG metrics.

RESULTS

During a median follow-up of 6.75 years, we identified 2323 cases of CVD and 1724 cases of all-cause mortality. Per 1-standard deviation increase in cumulative FBG load was associated with a 16 % higher risk of CVD (hazard ratio [HR]: 1.16; 95 % confidence interval [CI], 1.13-1.20) and 20 % higher risk of all-cause mortality (HR, 1.20; 95 % CI, 1.16-1.25). For the prediction of cardiovascular outcomes and all-cause mortality, cumulative FBG load outperformed FBG time-in-target, visit-to-visit FBG variability, and mean FBG in terms of C-statistics and reclassification indexes.

CONCLUSIONS

Cumulative FBG load may provide a better prediction of cardiovascular outcomes compared with other FBG metrics in the general population. These findings emphasized the important role of cumulative FBG load in assessing cardiovascular and mortality risk.

Serum 25-hydroxyvitamin D level is associated with short-term glycemic variability metrics derived from continuous glucose monitoring in T2DM

This study aims to investigate the association between 25-hydroxyvitamin D (25OHD) and continuous glucose monitoring-assessed short-term glycemic variability (GV) and HbA1c among patients with type 2 diabetes mellitus (T2DM). We conducted a cross-sectional study recruiting 325 patients. The association between 25OHD and GV metrics (mean amplitude of glycemic excursions [MAGE], coefficient of variation [CV], standard deviation of sensor glucose [SD], and TIR) and HbA1c were analyzed using multivariable linear and logistic regression analyses. The 25OHD level and GV metrics showed significant differences among HbA1c groups (P < 0.01). CV, MAGE, SD and HbA1c decreased, and TIR increased with ascending 25OHD tertiles (P < 0.05). Serum 25OHD was inversely associated with CV (β = - 0.211 [- 0.350 to - 0.071], P < 0.01) and HbA1c (β = - 0.061 [- 0.114 to - 0.031], P < 0.01), and further multivariable analyses confirmed these results (P < 0.05). However, no association of HbA1c and 25OHD was found with the highest tertile of CV. These findings revealed that increased GV and HbA1c were both associated with lower 25OHD, and the relationship between HbA1c and 25OHD was attenuated with higher glucose CV in T2DM. Taken together, the analyses suggest that increasing vitamin D status has effects on improvements in long-term glycemic control and low glycemic variability.

Visit-to-Visit Variability in Fasting Blood Glucose Predicts the New-Onset Heart Failure: Results From Two Large Chinese Cohorts

Previous studies have hypothesized an association between higher fasting blood glucose (FBG) and heart failure (HF). However, FBG values fluctuate continuously over time, the association between FBG variability and the risk of HF is uncertain. We investigated the relationship between visit-to-visit variability in FBG and the risk of new-onset HF. This cohort study used data from a prospective Kailuan cohort (recruited during 2006-2007) and a retrospective cohort of family medicine patients from Hong Kong (recruited during 2000-2003) were followed up until December 31st, 2016, and December 31st, 2019, respectively, for the outcome of incident HF. Four indexes of variability were used, including standard deviation (SD), coefficient of variation (CV), variability independent of the mean (VIM), and average real variability (ARV). Cox regression was used to identify HF. In total, 98,554 and 22,217 subjects without preexisting HF from the Kailuan and Hong Kong cohorts were analyzed, respectively, with 1218 cases of incident HF in the former and 4,041 in the latter. Subjects in the highest quartile of FBG-CV had the highest risk of incident HF in both cohorts (Kailuan: HR 1.245, 95% CI 1.055-1.470); Hong Kong: HR 1.362, 95%CI 1.145-1.620; compared with the lowest quartile). Similar results were observed when using FBG-ARV, FBG-VIM, and FBG-SD. Meta-analysis showed similar results (highest versus lowest quartile: HR 1.30, 95%CI 1.15-1.47, P < 0.0001). As observed from 2 large, geographically distinct Chinese cohorts, a higher FBG variability was independently associated with higher risk of incident HF.

Association of fasting blood glucose variability with all-cause mortality in heart transplant recipients

BACKGROUND

Fasting blood glucose (FBG) variability, an emerging marker of glycemic control, has been shown to be related to the risk of cardiovascular events and all-cause mortality in subjects with or without diabetes. However, whether FBG variability is independently associated with a higher all-cause mortality in heart transplant recipients remains unknown.

METHODS

We performed a retrospective cohort study including 373 adult recipients who survived for at least 1 year after heart transplantation with a functioning graft and measured FBG more than three times within first year after transplantation. Multivariable adjusted Cox regression analyses were performed to assess the association between FBG variability and all-cause mortality.

RESULTS

Patients were categorized into three groups according to the coefficient of variation of FBG level: ≤7.0%, 7.0%-13.5%, and >13.5%. During a median follow-up of 44.4 months (interquartile range [IQR], 22.6-63.3 months), 31 (8.3%) participants died. In univariate analyses, FBG variability was associated with an increased all-cause mortality (hazard ratio [HR]: 3.00, 95% confidence interval [CI]: 1.67, 5.38; p < .001). This association remained materially unchanged in the multivariable model adjusted for components of demographics, cardiovascular history and lifestyle, hospital information, immunosuppressive therapy, and post-transplant renal function (HR: 2.75, 95% CI: 1.43, 5.28; p = .004).

CONCLUSIONS

After heart transplantation, high FBG variability is strongly and independently associated with an increased risk of all-cause mortality. Our findings suggest that FBG variability is a novel risk factor and prognostic marker for heart transplantation recipients in outpatient clinic.

Relationship between Diabetic Nephropathy and Development of Diabetic Macular Edema in Addition to Diabetic Retinopathy

This study aimed to examine the relationship between diabetic retinopathy (DR) and systemic factors. We evaluated 261 patients (143 men, 118 women, aged 70.1 ± 10.1 years) with type 2 diabetes. All participants underwent a fundus examination, fundus photography using spectral domain optical coherence tomography (SD-OCT), and blood tests. For glycated hemoglobin (HbA1c) levels, the average and highest values in the past were used. We observed DR in 127 (70 men and 57 women) of 261 patients. Logistic regression analyses revealed a significant correlation between DR development and the duration of diabetes (OR = 2.40; 95% CI: 1.50), average HbA1c level (OR = 5.57; 95% CI: 1.27, 24.4), highest HbA1c level (OR = 2.46; 95% CI: 1.12, 5.38), and grade of diabetic nephropathy (DN) (OR = 6.23; 95% CI: 2.70, 14.4). Regression analyses revealed a significant correlation between the severity of DR and duration of diabetes (t = -6.66; 95% CI: 0.21, 0.39), average HbA1c level (t = 2.59; 95% CI: 0.14, 1.02), and severity of DN (t = 6.10; 95% CI: 0.49, 0.97). Logistic regression analyses revealed a significant correlation between diabetic macular edema (DME) development and DN grade (OR = 2.22; 95% CI: 1.33, 3.69). DN grade correlates with the development of DR and DME, and decreased renal function predicts the onset of DR.

Long-Term Visit-to-Visit Glycemic Variability as a Predictor of Major Adverse Limb and Cardiovascular Events in Patients With Diabetes

Background Peripheral arterial disease (PAD) is a severe complication in patients with type 2 diabetes. Glycemic variability (GV) is associated with increased risks of developing microvascular and macrovascular diseases. However, few studies have focused on the association between GV and PAD. Methods and Results This cohort study used a database maintained by the National Taiwan University Hospital, a tertiary medical center in Taiwan. For each individual, GV parameters were calculated, including fasting glucose coefficient of variability (FGCV) and hemoglobin A1c variability score (HVS). Multivariate Cox regression models were constructed to estimate the relationships between GV parameters and composite scores for major adverse limb events (MALEs) and major adverse cardiovascular events (MACEs). Between 2014 and 2019, a total of 45 436 adult patients with prevalent type 2 diabetes were enrolled for analysis, and GV was assessed during a median follow-up of 64.4 months. The average number of visits and time periods were 13.38 and 157.87 days for the HVS group and 14.27 and 146.59 days for the FGCV group, respectively. The incidence rates for cardiac mortality, PAD, and critical limb ischemia (CLI) were 5.38, 20.11, and 2.41 per 1000 person-years in the FGCV group and 5.35, 20.32, and 2.50 per 1000 person-years in HVS group, respectively. In the Cox regression model with full adjustment, the highest FGCV quartile was associated with significantly increased risks of MALEs (hazard ratio [HR], 1.57 [95% CI, 1.40-1.76]; P<0.001) and MACEs (HR, 1.40 [95% CI, 1.25-1.56]; P<0.001). Similarly, the highest HVS quartile was associated with significantly increased risks of MALEs (HR, 1.44 [95% CI, 1.28-1.62]; P<0.001) and MACEs (HR, 1.28 [95% CI, 1.14-1.43]; P<0.001). The highest FGCV and HVS quartiles were both associated with the development of PAD and CLI (FGCV: PAD [HR, 1.57; P<0.001], CLI [HR, 2.19; P<0.001]; HVS: PAD [HR, 1.44; P<0.001], CLI [HR, 1.67; P=0.003]). The Kaplan-Meier analysis showed significantly higher risks of MALEs and MACEs with increasing GV magnitude (log-rank P<0.001). Conclusions Among individuals with diabetes, increased GV is independently associated with the development of MALEs, including PAD and CLI, and MACEs. The benefit of maintaining stable glycemic levels for improving clinical outcomes warrants further studies.

Elevation of hemoglobin A1c increases the risk of decline in left ventricular systolic function among patients with coronary artery disease

AIMS

The aim of this study was to investigate the association of HbA1c and left ventricular (LV) systolic function among patients with coronary artery disease (CAD).

METHODS

CAD patients from the Cardiorenal ImprovemeNt II (CIN-II, NCT05050877) registry were included in the study. They were separated into four groups based on HbA1c levels (Q1: HbA1c<5.7%; Q2: 5.7% ≤ HbA1c < 6.1%; Q3: 6.1% ≤ HbA1c < 6.9%; Q4: HbA1c ≥ 6.9%). The endpoint was decline in LV systolic function, defined as an absolute decrease in LV ejection fraction (LVEF) ≥10% from baseline to follow-up with 3-12 months. The association of HbA1c and LVEF was assessed by logistics regression models.

RESULTS

CAD patients (n = 3,994) (age 62.9 ± 10.6 years; 22.2% female) were included in the final analysis. A decline in LV systolic function was recorded in 429 (11%) patients during follow-up. After fully adjusting for confounders, HbA1c was significantly associated with the high risk of decline in LV systolic function (OR 1.12 [95%CI 1.05-1.20] P = 0.001). By stratifying HbA1c as four groups, there is a significantly increased risk of decline in LV systolic function when HbA1c ≥6.1% (Q2, Q3 and Q4 vs Q1, with OR 1.22 [0.88-1.68] P = 0.235; OR 1.48 [1.07-2.05] P = 0.019; OR 1.60 [1.160-2.22] P = 0.004, respectively). Meanwhile, patients with decline in LV systolic function had a higher risk of cardiovascular death.

CONCLUSIONS

Elevated HbA1c is a predictor of decline in LV systolic function in CAD patients. Clinicians should be aware of the risk of decline in LV systolic function in CAD patients with elevated HbA1c, and take measures as soon as possible.

Effect of repeated bolus and continuous glucose infusion on a panel of circulating biomarkers in healthy volunteers

HYPOTHESIS

Glycaemic variability (GV) refers to fluctuations in the blood glucose level and may contribute to complications in patients suffering from Diabetes. Several studies show negative effects of GV on the cardiovascular system, however there is still a lack of conclusive evidence. Using an explorative cardiovascular panel, it is possible to simultaneously measure the effects on proteins relevant for cardiovascular processes. The aim of this study was to investigate the effects of rapid glucose excursions on cardiovascular and metabolic parameters in healthy individuals.

METHODS

An explorative single-blinded cross-over study was performed in ten healthy men. Subjects received 3 times 20 grams of glucose i.v. over 5 minutes or 60 grams of glucose continuously over 3 hours. Blood was taken for repeated measurements of the cardiovascular panel over the following 6 hours and again after 24 and 48 hours.

RESULTS

We observed a significant elevation of 7 cardiovascular biomarkers (BMP6, SLAMF7, LOX-1, ADAMTS13, IL-1RA, IL-4RA, PTX3) at t = 360min after rapid glucose infusion compared to a continuous glucose infusion.

CONCLUSIONS

Intraday GV seems to have acute effects on cardiovascular proteins in healthy test persons. Rapid glucose administration compared to continuous administration showed significant changes in BMP6, SLAMF7, ADAMTS13, IL1RA, PTX3, IL-4RA and LOX-1.

CLINICAL TRIAL REGISTRATION

NCT04488848.

Visit-to-visit variability in triglyceride-glucose index and diabetes: A 9-year prospective study in the Kailuan Study

INSTRUCTION/AIMS

It is unknown whether variability in the triglyceride-glucose index (TyG-index) is associated with the risk of diabetes. Here, we sought to characterize the relationship between TyG-index variability and incident diabetes.

METHODS

We performed a prospective study of 48,013 participants in the Kailuan Study who did not have diabetes. The TyG-index was calculated as ln [triglyceride (TG, mg/dL) concentration × fasting blood glucose concentration (FBG, mg/dL)/2]. The TyG-index variability was assessed using the standard deviation (SD) of three TyG-index values that were calculated during 2006/07, 2008/09, and 2010/11. We used the Cox proportional hazard models to analyze the effect of TyG-index variability on incident diabetes.

RESULTS

A total of 4,055 participants were newly diagnosed with diabetes during the study period of 8.95 years (95% confidence interval (CI) 8.48-9.29 years). After adjustment for confounding factors, participants in the highest and second-highest quartiles had significantly higher risks of new-onset diabetes versus the lowest quartile, with hazard ratios (95% CIs) of 1.18 (1.08-1.29) and 1.13 (1.03-1.24), respectively (P trend< 0.05). These higher risks remained after further adjustment for the baseline TyG-index.

CONCLUSIONS

A substantial fluctuation in TyG-index is associated with a higher risk of diabetes in the Chinese population, implying that it is important to maintain a normal and consistent TyG-index.

Long-term fasting glucose variability and risk of cancer in patients with type 2 diabetes mellitus: A retrospective population-based cohort study in Shanghai

BACKGROUNDS

Fasting blood glucose (FBG) variability may make an impact on adverse events in patients with diabetes mellitus. However, the association between long-term changes in FBG and cancer remains unclear. We aimed to investigate this association in a large-scale longitudinal study.

METHODS

Data were collected from 46 761 patients with type 2 diabetes mellitus aged 20-80 years who participated in the Diabetes Standardized Management Program in Shanghai, China. We adopted four indicators, including standard deviation (SD), coefficient of variation (CV), variation independent of the mean (VIM), and average real variability (ARV) to describe FBG variability. Adjusted multivariable Cox regression analyses and restricted cubic splines were used to investigate the association between long-term FBG variability and cancer risk. We also determined the interactive effect of FBG variability with hypertension and FBG-mean with hypertension on cancer risk, respectively.

RESULTS

In this study, we confirmed 2218 cancer cases (51.1% male) over a median follow-up of 2.86 years. In the multivariable-adjusted models, participants in the highest quartile of FBG variability had an increased risk of cancer compared with those in the lowest quartile. The nonlinear association was found when using FBG-VIM, FBG-ARV, and FBG-SD in restricted cubic spline plots. There was a significant interaction effect of FBG variability with hypertension on cancer, whereas the effect of FBG-mean with hypertension did not attain significance.

CONCLUSIONS

Our retrospective cohort study demonstrated a positive association between the long-term changes in FBG and cancer risk in patients with type 2 diabetes mellitus. FBG variability may independently predict cancer incidence.

A Tryptophan Metabolite of the Microbiota Improves Neovascularization in Diabetic Limb Ischemia

Diabetes mellitus (DM) is accompanied by a series of macrovascular and microvascular injuries. Critical limb ischemia is the most severe manifestation of peripheral artery disease (PAD) caused by DM and is almost incurable. Therapeutic modulation of angiogenesis holds promise for the prevention of limb ischemia in diabetic patients with PAD. However, no small-molecule drugs are capable of promoting diabetic angiogenesis. An endogenous tryptophan metabolite, indole-3-aldehyde (3-IAld), has been found to have proangiogenic activity in endothelial cells. Nevertheless, the role of 3-IAld in diabetic angiogenesis remains unknown. Here, we found that 3-IAld ameliorated high glucose-induced mitochondrial dysfunction, decreasing oxidative stress and apoptosis and thus improving neovascularization.

Time in range, as measured by continuous glucose monitor, as a predictor of microvascular complications in type 2 diabetes: a systematic review

Continuous glucose monitoring (CGM)-derived time in range (TIR) correlates with hemoglobin A1c (A1c) among patients with type 2 diabetes mellitus (T2DM); however, there is a paucity of data evaluating its association with microvascular complications. We conducted this systematic review to examine the association between TIR and microvascular complications of diabetic retinopathy (DR), diabetic nephropathy (DN), and diabetic peripheral neuropathy (DPN). We conducted a comprehensive literature search on PubMed, Scopus, and Web of Science online databases following the Preferred Reporting Items for Systematic Reviews and Meta-Analyses guidelines. Full-text original articles that evaluated the association between CGM-derived TIR and risk of microvascular complications and were published between 2010 and June 2021 were included in our systematic review. The quality of the included studies was evaluated using the National Heart, Lung, and Blood Institute Quality Assessment Tool for Observational Cohort and Cross-Sectional Studies. Data were analyzed using qualitative synthesis. Eleven studies on a total of 13 987 patients were included in the systematic review. The median sample size, baseline A1c, and diabetes duration were 466 patients (range: 105-5901), 8.2% (SD 0.5%), and 11.3 years (1.0), respectively. Majority of the studies were conducted in Asia (10 out of 11). Four studies evaluated the relationship between CGM-derived TIR and DR and CGM-derived TIR and DN, while seven studies evaluated the relationship between CGM-derived TIR and DPN. A 10% increase in TIR was associated with a reduction in albuminuria, severity of DR, and prevalence of DPN and cardiac autonomic neuropathy. In addition, an association was observed between urinary albumin to creatinine ratio but not with estimated glomerular filtration rate. This review summarizes recent evidence supporting an association between CGM-derived TIR and microvascular complications among patients with T2DM. A larger-scale multicenter investigation that includes more diverse participants is warranted to further validate the utility of TIR as a predictor of diabetic microvascular complications.

Association between visit-to-visit variability of glycemic indices and lipid profile and the incidence of coronary heart disease in adults with type 2 diabetes

Coronary heart disease (CHD) is one of the major causes of mortality and morbidity in patients with type 2 diabetes mellitus. In this study, we aimed to assess the association between visit-to-visit variability of fasting blood sugar (FBS), HbA1c, blood sugar 2 h post-prandial (BS2hpp), lipid indices, creatinine, systolic and diastolic blood pressure (SBP, DBP) and incident CHD in patients with type 2 diabetes during a median follow-up of ten years. The current case-cohort study consisted of 1500 individuals with type 2 diabetes, followed up for the occurrence of CHD from 2002 to 2019. The patients had at least four annual follow-ups during which glycemic and lipid profile were measured. Co-efficient of variance (CV) for each parameter was calculated by 10-21 measurements. Cox regression analysis was performed to assess the association between CV of glycemic indices, lipid profile, blood pressure, creatinine, weight and incident CHD during the follow-up period. Hazard ratios (HR) were adjusted for the confounding variables. Glycemic indices variability (i.e., CV-HbA1c, CV-FBS, and CV-BS2hpp), were significantly higher in the group with incident CHD (P=0.034, P=0.042, and P=0.044, respectively). Hazard ratios were 1.42 (95 % CI=1.13-2.09) for CV-HbA1c, 1.37 (95 % CI=1.02-2.10) for CV-FBS, and 1.16 (95 % CI=1.01-1.63) for CV-BS2hpp (P=0.012, P=0.046, P=0.038, respectively). Creatinine was significantly higher in the group with incident CHD (P=0.036) and it was significantly associated with higher incidence of CHD (HR=1.14, 95 % CI=1.02-2.17, P=0.048). Visit to visit variability of glycemic indices of the patients with type 2 diabetes is associated with incident CHD independent of their baseline and mean values.

Association of HbA1c With All-cause Mortality Across Varying Degrees of Glycemic Variability in Type 2 Diabetes

CONTEXT

The interaction of glycated hemoglobin A1c (HbA1c) and glycemic variability in relation to diabetes-related outcomes remains unknown.

OBJECTIVE

To evaluate the relationship between HbA1c and all-cause mortality across varying degrees of glycemic variability in patients with type 2 diabetes.

DESIGN, SETTING, AND PATIENTS

This was a prospective study conducted in a single referral center. Data of 6090 hospitalized patients with type 2 diabetes was analyzed. Glucose coefficient of variation [coefficient of variation (CV)] was obtained as the measure of glycemic variability by using continuous glucose monitoring for 3 days. Cox proportional hazards regression models were used to estimate hazard ratios and 95% CIs for all-cause mortality.

RESULTS

During a median follow-up of 6.8 years, 815 patients died. In patients with the lowest and middle tertiles of glucose CV, HbA1c ≥ 8.0% was associated with 136% (95% CI 1.46-3.81) and 92% (95% CI 1.22-3.03) higher risks of all-cause mortality, respectively, as compared with HbA1c 6.0%-6.9%, after adjusting for confounders. However, a null association of HbA1c with mortality was found in patients with the highest tertile of glucose CV.

CONCLUSIONS

HbA1c may not be a robust marker of all-cause mortality in patients with high degree of glycemic variability. New metrics of glycemic control may be needed in these individuals to achieve better diabetes management.

Visit-to-visit fasting blood glucose variability and lifetime risk of cardiovascular disease: a prospective study

Aims

Previous studies suggested an adverse association between higher fasting blood glucose (FBG) variability and cardiovascular disease (CVD). Lifetime risk provides an absolute risk assessment during the remainder of an individual’s life. However, the association between FBG variability and the lifetime risk of CVD is uncertain.

Objective

We aimed to investigate the effect of the visit-to-visit FBG variability on the lifetime risk of CVD.

Methods

This study included participants from the Kailuan Study who did not have CVD at index ages 35, 45, and 55 years. The FBG variability was defined as the coefficient of variation (CV) of three FBG values that were measured during the examination periods of 2006–2007, 2008–2009, and 2010–2011. We used a modified Kaplan-Merrier method to estimate lifetime risk of CVD according to tertiles of FBG variability.

Results

At index age 35 years, the study sample comprised 46,018 participants. During a median follow-up of 7.0 years, 1889 participants developed CVD events. For index age 35 years, participants with high FBG variability had higher lifetime risk of CVD (32.5%; 95% confidence interval [CI]: 28.9–36.1%), compared with intermediate (28.3%; 95% CI: 25.5 –31.1%) and low (26.3%; 95% CI: 23.0–29.5%) FBG variability. We found that higher FBG variability was associated with increased lifetime risk of CVD in men but not women. Similar patterns were observed at index ages 45 and 55 years.

Conclusions

Higher FBG variability was associated with increased lifetime risk of CVD at each index age. Focusing on the FBG variability may provide an insight to the clinical utility for reducing the lifetime risk of CVD.

Supplementary Information

The online version contains supplementary material available at 10.1186/s12933-021-01397-1.

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.

Glucose Variability: How Does It Work?

A growing body of evidence points to the role of glucose variability (GV) in the development of the microvascular and macrovascular complications of diabetes. In this review, we summarize data on GV-induced biochemical, cellular and molecular events involved in the pathogenesis of diabetic complications. Current data indicate that the deteriorating effect of GV on target organs can be realized through oxidative stress, glycation, chronic low-grade inflammation, endothelial dysfunction, platelet activation, impaired angiogenesis and renal fibrosis. The effects of GV on oxidative stress, inflammation, endothelial dysfunction and hypercoagulability could be aggravated by hypoglycemia, associated with high GV. Oscillating hyperglycemia contributes to beta cell dysfunction, which leads to a further increase in GV and completes the vicious circle. In cells, the GV-induced cytotoxic effect includes mitochondrial dysfunction, endoplasmic reticulum stress and disturbances in autophagic flux, which are accompanied by reduced viability, activation of apoptosis and abnormalities in cell proliferation. These effects are realized through the up- and down-regulation of a large number of genes and the activity of signaling pathways such as PI3K/Akt, NF-κB, MAPK (ERK), JNK and TGF-β/Smad. Epigenetic modifications mediate the postponed effects of glucose fluctuations. The multiple deteriorative effects of GV provide further support for considering it as a therapeutic target in diabetes.

Glycemic variability and the risk of nonalcoholic fatty liver disease : A nationwide population-based cohort study

AIM

Although few recent studies have reported the association between the glycemic variability and the development of type 2 diabetes mellitus and cardiovascular disease in individuals without diabetes mellitus, the impact of the long-term variability in fasting plasma glucose (FPG) levels on the incident nonalcoholic fatty liver disease (NAFLD) has not been evaluated.

METHODS

The study included 57,636 Korean men and women without NAFLD and diabetes mellitus from the Korean National Health Insurance System cohort. FPG variability was calculated using the coefficient of variation (FPG-CV), standard deviation (FPG-SD), variability independent of the mean (FPG-VIM), and average successive variability (FPG-ASV).

RESULTS

The cumulative incidence of NAFLD demonstrated progressively increasing trends according to the higher quartiles of FPG variability in Kaplan-Meier curves. A multivariable Cox proportional hazard analysis revealed that the hazard ratio for incident NAFLD was 1.15 (95% confidence interval, 1.06-1.24) in the highest quartile of FPG-CV compared with the lowest quartile of FPG-CV after adjusting for various confounding factors, including mean FPG levels. When using FPG-SD, FPG-VIM, and FPG-ASV, the results were similar. The 10-unit increase in FPG variability was associated with a 14% increased risk of NAFLD in the fully adjusted model. Moreover, this effect remained consistent in the subgroup and sensitivity analyses.

CONCLUSION

Increased long-term FPG variability is associated with the development of NAFLD, independent of confounding risk variables including mean FPG levels.

Increased PARylation impacts the DNA methylation process in type 2 diabetes mellitus

Background

Epigenetic modifications, such as DNA methylation, can influence the genetic susceptibility to type 2 diabetes mellitus (T2DM) and the progression of the disease. Our previous studies demonstrated that the regulation of the DNA methylation pattern involves the poly(ADP-ribosyl)ation (PARylation) process, a post-translational modification of proteins catalysed by the poly(ADP-ribose) polymerase (PARP) enzymes. Experimental data showed that the hyperactivation of PARylation is associated with impaired glucose metabolism and the development of T2DM. Aims of this case–control study were to investigate the association between PARylation and global and site-specific DNA methylation in T2DM and to evaluate metabolic correlates.

Results

Data were collected from 61 subjects affected by T2DM and 48 healthy individuals, recruited as controls. Global levels of poly(ADP-ribose) (PAR, a surrogate of PARP activity), cytosine methylation (5-methylcytosine, 5mC) and de-methylation intermediates 5-hydroxymethylcytosine (5hmC) and 5-formylcytosine (5fC) were determined in peripheral blood cells by ELISA-based methodologies. Site-specific DNA methylation profiling of SOCS3, SREBF1 and TXNIP candidate genes was performed by mass spectrometry-based bisulfite sequencing, methyl-sensitive endonucleases digestion and by DNA immuno-precipitation. T2DM subjects presented higher PAR levels than controls. In T2DM individuals, increased PAR levels were significantly associated with higher HbA1c levels and the accumulation of the de-methylation intermediates 5hmC and 5fC in the genome. In addition, T2DM patients with higher PAR levels showed reduced methylation with increased 5hmC and 5fC levels in specific SOCS3 sites, up-regulated SOCS3 expression compared to both T2DM subjects with low PAR levels and controls.

Conclusions

This study demonstrates the activation of PARylation processes in patients with T2DM, particularly in those with poor glycaemic control. PARylation is linked to dysregulation of DNA methylation pattern via activation of the DNA de-methylation cascade and may be at the basis of the differential gene expression observed in presence of diabetes.

Supplementary Information

The online version contains supplementary material available at 10.1186/s13148-021-01099-1.

Stress hyperglycemia may have higher risk of stroke recurrence than previously diagnosed diabetes mellitus

We aim to evaluate the risk of stroke recurrence among non-diabetes mellitus (non-DM), previously diagnosed diabetes mellitus (PDDM), newly diagnosed diabetes mellitus-related hyperglycemia (NDDM-RH) and stress hyperglycemia after minor stroke or TIA. Totally, 3026 patients with baseline fasting glucose and glycated albumin from the CHANCE trial (Clopidogrel in High-Risk Patients with Acute Nondisabling Cerebrovascular Events) were included. Patients were classified as non-DM, PDDM, NDDM-RH and stress hyperglycemia according to the status of glucose metabolism. The primary outcome was stroke recurrence during 90-day follow up. Cox regression was performed to estimate the relationship between the status of glucose metabolism and risk of 90-day stroke recurrence. Compared with PDDM, NDDM-RH had a similar risk of 90-day stroke recurrence (hazard ratios [HR]1.39, 95% confidence intervals [CI] 0.94-2.04), while stress hyperglycemia had approximately a 5.3-fold increased risk of 90-day stroke recurrence after adjusted for confounding covariates (HR 5.32, 95% CI 3.43-8.26). Parallel results were found for 90-day recurrent ischemic stroke and composite events. Compared with PDDM in minor stroke or TIA, a parallel risk of 90-day stroke recurrence were observed for NDDM-RH, while stress hyperglycemia might relate to higher risk of 90-day stroke recurrence.

Effects of salubrinal on ER stress in an experimental model of polycystic ovary syndrome

This study aimed to investigate the role of endoplasmic reticulum (ER) stress in polycystic ovary syndrome (PCOS) and the effect of salubrinal (SAL) on this role. Animals were divided into four groups as control, PCOS, PCOS+SAL and SAL. Weights and serum testosterone levels were increased in the PCOS group while serum LH and ATF4 expressions were decreased. Morphometrically, number of follicles with a diameter between 150 and 300 µm were declined and number of follicles larger than 300 µm as well as the percentage of cystic follicles (CFs) were increased. Immunoreactivities of GRP78 and p-eIF2α were decreased, whereas oxidative stress (OS) dependent PAR expression was increased. Ultrastructurally, the PCOS group had no ER enlargement which was observed in the control group, while there were mitochondrial damage in granulosa cells (GCs). Elevated OS levels did not induce but rather decreased ER stress in GCs, and SAL injection in the PCOS model was ineffective on searched parameters. Since ER stress plays roles in certain physiological processes, we suggest that inhibitors of ER stress may not be always useful for reproductive tissues.

Knockdown of SGLT1 prevents the apoptosis of cardiomyocytes induced by glucose fluctuation via relieving oxidative stress and mitochondrial dysfunction

Fluctuations in the concentration of glucose in the blood is more detrimental than a constantly high level of glucose with respect to the development of cardiovascular complications associated with diabetes mellitus (DM). Sodium glucose cotransporter 2 (SGLT2) inhibitors have been developed as antidiabetic drugs with cardiovascular benefits; however, whether inhibition of SGLT1 protects the diabetic heart remains to be determined. This study investigated the role of SGLT1 in rat H9c2 cardiomyocytes subjected to fluctuating levels of glucose and the underlying mechanisms. The results indicated that knockdown of SGLT1 restored cell proliferation and suppressed the cytotoxicity associated with fluctuating glucose levels. Oxidative stress was induced in H9c2 cells subjected to fluctuating glucose levels, but these changes were effectively reversed by knockdown of SGLT1, as manifested by reductions in the level of intracellular reactive oxygen species and increased antioxidant activity. Further study demonstrated that knockdown of SGLT1 attenuated the mitochondrial dysfunction in H9c2 cells exposed to fluctuating glucose levels, by restoring mitochondrial membrane potential and promoting mitochondrial fusion. In addition, knockdown of SGLT1 downregulated the expression of Bax, upregulated the expression of Bcl-2, and reduced the activation of caspase-3 in H9c2 cells subjected to fluctuating levels of glucose. Collectively, our results show that knockdown of SGLT1 ameliorates the apoptosis of cardiomyocyte caused by fluctuating glucose levels via regulating oxidative stress and combatting mitochondrial dysfunction.

Visit-to-visit fasting plasma glucose variability is associated with left ventricular adverse remodeling in diabetic patients with STEMI

Background

Patients with type 2 diabetes mellitus (T2DM) are predisposed to poor cardiovascular outcomes after ST-segment elevation myocardial infarction (STEMI). Left ventricular adverse remodeling (LVAR) triggered upon myocardial infarction is recognized as the predominant pathological process in the development of heart failure. In the present study, we sought to investigate whether visit-to-visit fasting plasma glucose (FPG) variability is a potential predictor of LVAR in T2DM patients after STEMI.

Methods

From January 2014 to December 2018 in Ruijin Hospital, T2DM patients with STEMI who underwent primary percutaneous coronary intervention were consecutively enrolled and followed up for ~ 12 months. The changes in left ventricular geometric and functional parameters between baseline and 12-month follow-up were assessed by echocardiography. The incidence of LVAR, defined as 20% increase in indexed left ventricular end-diastolic volume (LVEDV), and its relationship with visit-to-visit FPG variability were analyzed. Multivariate regression models were constructed to test the predictive value of FPG variability for post-infarction LVAR.

Results

A total of 437 patients with type 2 diabetes and STEMI were included in the final analysis. During a mean follow-up of 12.4 ± 1.1 months, the incidence of LVAR was 20.6% and mean enlargement of indexed LVEDV was 3.31 ± 14.4 mL/m², which was significantly increased in patients with higher coefficient variance (CV) of FPG (P = 0.002) irrespective of baseline glycemic levels. In multivariate analysis, FPG variability was independently associated with incidence of post-infarction LVAR after adjustment for traditional risk factors, baseline HbA1c as well as mean FPG during follow-up (OR: 3.021 [95% CI 1.081–8.764] for highest vs. lowest tertile of CV of FPG). Assessing FPG variability by other two measures, including standard deviation (SD) and variability independent of the mean (VIM), yielded similar findings.

Conclusions

This study suggests that visit-to-visit FPG variability is an independent predictor of incidence of LVAR in T2DM patients with STEMI.

Trial registration Trials number, NCT02089360; registered on March 17,2014.

Long-term tracking of fasting blood glucose variability and peripheral artery disease in people without diabetes

INTRODUCTION

Long-term changes of fasting blood glucose (FBG) in relation to lower-extremity peripheral artery disease (lower-extremity PAD) in people without diabetes has barely been reported. Our study aimed to investigate the association between FBG variability and the incidence of lower-extremity PAD in people without diabetes.

RESEARCH DESIGN AND METHODS

We included 7699 participants without prior lower-extremity PAD and diabetes from the Atherosclerosis Risk in Communities study in the final analysis. At least two measurements of FBG were required during follow-up. Variability of FBG was identified using SD, coefficient of variation (CV), variability independent of the mean (VIM) and average real variability. Lower-extremity PAD was defined as an ankle brachial index <0.9, or hospitalization with a lower-extremity PAD diagnosis. Cox regression model was used to calculate HR for incidence of lower-extremity PAD and FBG variability.

RESULTS

During a median follow-up of 19.5 years, 504 (6.5 %) lower-extremity PAD events were observed, 54.4% (n=274) were male, and 17.5% (n=88) were African-American. FBG variability was positively associated with incident lower-extremity PAD, with a linear relationship. HRs for CV and VIM were 1.015 (95% CI: 1.001 to 1.03; p=0.023), and 1.032 (95% CI: 1.004 to 1.06; p=0.022) for lower-extremity PAD, respectively. Participants in the lowest quartile of CV were at lower lower-extremity PAD risk compared with the highest ones (HR: 1.499, 95% CI: 1.16 to 1.938; p=0.002).

CONCLUSIONS

Higher FBG variability was independently associated with increased prevalence of lower-extremity PAD in people without diabetes.

TRIAL REGISTRATION NUMBER

NCT00005131.

The relationship between glycaemic variability and cardiovascular autonomic dysfunction in patients with type 1 diabetes: A systematic review

Rigorous glycaemic control-reflected by low HbA1c goals-is of the utmost importance in the prevention and management of complications in patients with type 1 diabetes mellitus (T1DM). However, previous studies suggested that short-term glycaemic variability (GV) is also important to consider as excessive glucose fluctuations may have an additional impact on the development of diabetic complications. The potential relationship between GV and the risk of cardiovascular autonomic neuropathy (CAN), a clinical expression of cardiovascular autonomic dysfunction, is of increasing interest. This systematic review aimed to summarize existing evidence concerning the relationship between GV and cardiovascular autonomic dysfunction in T1DM. An electronic database search of Medline (PubMed), Web of Science and Embase was performed up to October 2019. There were no limits concerning year of publication. Methodological quality was evaluated using the Newcastle Ottawa Scale for observational studies. Six studies (four cross-sectional and two prospective cohorts) were included. Methodological quality of the studies varied from level C to A2. Two studies examined the association between GV and heart rate variability (HRV), and both found significant negative correlations. Regarding cardiovascular autonomic reflex tests (CARTs), two studies did not, while two other studies did find significant associations between GV parameters and CART scores. However, associations were attenuated after adjusting for covariates such as HbA1c, age and disease duration. In conclusion, this systematic review found some preliminary evidence supporting an association between GV and cardiovascular autonomic dysfunction in T1DM. Hence, uncertainty remains whether high GV can independently contribute to the onset or progression of CAN. The heterogeneity in the methodological approach made it difficult to compare different studies. Future studies should therefore use uniformly evaluated continuous glucose monitoring-derived parameters of GV, while standardized assessment of HRV, CARTs and other potential cardiac autonomic function parameters is needed for an unambiguous definition of CAN.

Cardiovascular autonomic neuropathy: A silent killer with long reach

Cardiovascular autonomic neuropathy (CAN) is a common and deadly complication of diabetes mellitus, which is frequently overlooked in clinical practice due to its characteristic subtle presentation earlier in disease. Yet, timely detection of CAN may help implementation of tailored interventions to prevent its progression and mitigate the risk of associated complications, including cardiovascular disease (CVD), cardiac arrhythmias, myocardial dysfunction leading to congestive heart failure and all-cause mortality. This review highlights current CAN epidemiology trends, novel mechanisms linking CAN with other diabetes complications and current recommendations for diagnosis and management of the disease in the clinical setting.

1α,25-Dihydroxyvitamin D3 prevents renal oxidative damage via the PARP1/SIRT1/NOX4 pathway in Zucker diabetic fatty rats

Diabetic nephropathy (DN) is one of the most important renal complications associated with diabetes, and the mechanisms are yet to be fully understood. To date, few studies have shown the antioxidant effects of 1α,25-dihydroxyvitamin-D₃ [1,25(OH)₂D₃] on hyperglycemia-induced renal injury. The aim of the present study was to explore the potential mechanism by which 1,25(OH)₂D₃ reduced oxidative stress in diabetic rat kidneys. In this study, we established a vitamin D-deficient spontaneous diabetes model: 5-6 wk of age Zucker diabetic fatty (ZDF) rats were treated with or without 1,25(OH)₂D₃ for 7 wk, age-matched Zucker lean rats served as control. Results showed that ZDF rats treated with 1,25(OH)₂D₃ had decreased body mass, food intake, water intake, and urine volume. 1,25(OH)₂D₃ ameliorated urine glucose, blood glucose and abnormal glucose tolerance. Additionally, 1,25(OH)₂D₃ significantly lowered microalbuminuria, decreased the glomerular basement membrane thickness, and in some degree inhibited glomerular hypertrophy, mesangial expansion, and tubular dilatation. Furthermore, 1,25(OH)₂D₃ attenuated renal oxidative damage, as reflected by the levels of malondialdehyde, reduced glutathione, 4-hydroxynonenal, 8-hydroxy-2'-deoxyguanosine, and reactive oxygen species production, and notably inhibited poly(ADP-ribose) polymerase-1 (PARP1), activated sirtuin 1 (SIRT1), and decreased the expression of NADPH oxidase 4 (NOX4). Of interest, the abovementioned proteins could be involved in the antioxidant mechanism of 1,25(OH)₂D₃ in diabetic rat kidneys. Our study showed that oxidative stress might be a major contributor to DN pathogenesis and uncovered the antioxidant role of 1,25(OH)₂D₃ in diabetic nephropathy that was associated with the PARP1/SIRT1/ NOX4 pathway.

Schwann cells apoptosis is induced by high glucose in diabetic peripheral neuropathy

Diabetic peripheral neuropathy (DPN) is a common complication of diabetes mellitus that affects approximately half of patients with diabetes. Current treatment regimens cannot treat DPN effectively. Schwann cells (SCs) are very sensitive to glucose concentration and insulin, and closely associated with the occurrence and development of type 1 diabetic mellitus (T1DM) and DPN. Apoptosis of SCs is induced by hyperglycemia and is involved in the pathogenesis of DPN. This review considers the pathological processes of SCs apoptosis under high glucose, which include the following: oxidative stress, inflammatory reactions, endoplasmic reticulum stress, autophagy, nitrification and signaling pathways (PI3K/AKT, ERK, PERK/Nrf2, and Wnt/β-catenin). The clarification of mechanisms underlying SCs apoptosis induced by high glucose will help us to understand and identify more effective strategies for the treatment of T1DM DPN.

Time in Range, as a Novel Metric of Glycemic Control, Is Reversely Associated with Presence of Diabetic Cardiovascular Autonomic Neuropathy Independent of HbA1c in Chinese Type 2 Diabetes

OBJECTIVE

The objective of this study is to investigate the relationship between time in range (TIR), a new metric of continuous glucose monitoring (CGM) and cardiovascular autonomic neuropathy (CAN) in individuals with type 2 diabetes mellitus (T2DM).

METHODS

A total of 349 individuals with T2DM were enrolled in this study. Evaluating by the standard cardiac autonomic reflex tests (CARTs), there were 228 diabetic individuals without cardiovascular autonomic neuropathy (without confirmed CAN) including absent CAN (n = 83 cases) and early CAN (n = 83 cases) and early CAN (n = 83 cases) and early CAN (n = 83 cases) and early CAN (.

RESULTS

The total presence of CAN was 34.67% (definite CAN 31.23% and severe CAN 3.44%). Patients with more severe CAN had lower TIR (P < 0.001). With increasing quartiles of TIR, the presence of CAN by severity declined (P < 0.001). With increasing quartiles of TIR, the presence of CAN by severity declined (P < 0.001). With increasing quartiles of TIR, the presence of CAN by severity declined (P < 0.001). With increasing quartiles of TIR, the presence of CAN by severity declined (.

CONCLUSION

TIR is associated with the presence of CAN independent of HbA1c and GV metrics in Chinese type 2 diabetes.

Association of Glycemic Indices (Hyperglycemia, Glucose Variability, and Hypoglycemia) with Oxidative Stress and Diabetic Complications

Oxidative stress (OS) is defined as a disturbance in the prooxidant-antioxidant balance of the cell, in favor of the former, which results in the antioxidant capacity of the cell to be overpowered. Excess reactive oxygen species (ROS) production is very harmful to cell constituents, especially proteins, lipids, and DNA, thus causing damage to the cell. Oxidative stress has been associated with a variety of pathologic conditions, including diabetes mellitus (DM), cancer, atherosclerosis, neurodegenerative diseases, rheumatoid arthritis, ischemia/reperfusion injury, obstructive sleep apnea, and accelerated aging. Regarding DM specifically, previous experimental and clinical studies have pointed to the fact that oxidative stress probably plays a major role in the pathogenesis and development of diabetic complications. It is postulated that hyperglycemia induces free radicals and impairs endogenous antioxidant defense systems through several different mechanisms. In particular, hyperglycemia promotes the creation of advanced glycation end-products (AGEs), the activation of protein kinase C (PKC), and the hyperactivity of hexosamine and sorbitol pathways, leading to the development of insulin resistance, impaired insulin secretion, and endothelial dysfunction, by inducing excessive ROS production and OS. Furthermore, glucose variability has been associated with OS as well, and recent evidence suggests that also hypoglycemia may be playing an important role in favoring diabetic vascular complications through OS, inflammation, prothrombotic events, and endothelial dysfunction. The association of these diabetic parameters (i.e., hyperglycemia, glucose variability, and hypoglycemia) with oxidative stress will be reviewed here.

Metabolic Profiling in Human Fibroblasts Enables Subtype Clustering in Glycogen Storage Disease

Glycogen storage disease subtypes I and III (GSD I and GSD III) are monogenic inherited disorders of metabolism that disrupt glycogen metabolism. Unavailability of glucose in GSD I and induction of gluconeogenesis in GSD III modify energy sources and possibly, mitochondrial function. Abnormal mitochondrial structure and function were described in mice with GSD Ia, yet significantly less research is available in human cells and ketotic forms of the disease. We hypothesized that impaired glycogen storage results in distinct metabolic phenotypes in the extra- and intracellular compartments that may contribute to pathogenesis. Herein, we examined mitochondrial organization in live cells by spinning-disk confocal microscopy and profiled extra- and intracellular metabolites by targeted LC-MS/MS in cultured fibroblasts from healthy controls and from patients with GSD Ia, GSD Ib, and GSD III. Results from live imaging revealed that mitochondrial content and network morphology of GSD cells are comparable to that of healthy controls. Likewise, healthy controls and GSD cells exhibited comparable basal oxygen consumption rates. Targeted metabolomics followed by principal component analysis (PCA) and hierarchical clustering (HC) uncovered metabolically distinct poises of healthy controls and GSD subtypes. Assessment of individual metabolites recapitulated dysfunctional energy production (glycolysis, Krebs cycle, succinate), reduced creatinine export in GSD Ia and GSD III, and reduced antioxidant defense of the cysteine and glutathione systems. Our study serves as proof-of-concept that extra- and intracellular metabolite profiles distinguish glycogen storage disease subtypes from healthy controls. We posit that metabolite profiles provide hints to disease mechanisms as well as to nutritional and pharmacological elements that may optimize current treatment strategies.

Switch-over Study with Fast-acting Insulin Aspart Showing Lower Glycemic Variability in Type 2 Diabetics with Stage 4 Chronic Kidney Disease: A Case Series

Background Despite conventional insulin treatment being considered an effective approach for glycemic regulation during renal dysfunction, there is still a major clinical need for better insulin therapy to stabilize fluctuations in glucose levels. Aim The aim of this study was to assess the impact of mealtime fast-acting insulin aspart therapy on glycemic variability as compared to regular human insulin therapy in advanced chronic kidney disease (CKD) patients with type 2 diabetes (T2D). Methods Data from eight patients were retrospectively collected after analyzing 57 patients' data between July 2019 and October 2019. All T2D patients with stage 4 CKD were switched to mealtime fast-acting insulin aspart on account of recurrent hypoglycemic events. The continuous glucose monitoring data of the first four days were analyzed to calculate the mean amplitude of glucose excursions (MAGE) as well as five other glycemic variability indices, namely, standard deviation, mean, continuous overall net glycemic action, average daily risk range, and J index. Results The primary endpoint of 24-h MAGE significantly decreased from 7.01 ± 2.59 to 4.19 ± 1.06 mg/dL (p = 0.012) when short-acting regular human insulin (RHI) therapy was replaced with mealtime fast-acting insulin aspart therapy. However, no significant change was observed in 24-h mean glucose levels and other indices of glucose variability. Significant reduction in 24-h and night-time hypoglycemic events was reported in patients after therapy switch during the four-day follow-up period. Conclusions The present study demonstrated an improvement in glycemic variability with the administration of fast-acting insulin aspart as compared to RHI, suggesting that modern bolus insulin replacement might prove to be a useful therapeutic strategy in type 2 diabetes patients with advanced CKD. Further clinical studies will be required to confirm the benefits of this therapeutic approach. Relevance for patients The safety and effectiveness of fast-acting insulin aspart in CKD patients have not yet been established. The clinical effectiveness and better safety profile of newer mealtime insulin therapy may prompt a reconsideration of its use in patients with an advanced stage of renal dysfunction, leading to better adherence and improved quality of life.

The relationship between glucose variability and insulin sensitivity and oxidative stress in subjects with prediabetes

AIM

The present study assessed the relationship between glucose variability (GV) and insulin levels, insulin resistance and oxidative stress at early stages of glucose intolerance.

MATERIAL AND METHODS

A total of 50 subjects - 12 males and 38 females, mean age 55.6 ± 9.7 years, mean BMI 28.4 ± 6.4 kg/m², divided into 2 groups according to glucose tolerance: 32 with prediabetes and 18 with normal glucose tolerance were included. Glucose tolerance was assessed by OGTT according to WHO 2006 criteria. Plasma glucose and serum insulin were measured at fasting, 120-minute and 180-minute during the test; and oxLDL and 3-Nitrotyrosine - at fasting and 120-minute. HOMA-IR and OGIS indexes were calculated. HbA1c and lipid levels was assessed. Continuous glucose monitoring was performed with a blind sensor (FreeStyle Libre Pro) for a mean period of 13.6 ± 2.3 days.

RESULTS

Our results demonstrate significantly increased insulin resistance in subjects with prediabetes, whereas there is no difference in oxidative stress markers between the two groups. OxLDL and 3-NT correlate positively with insulin levels and HOMA-IR and negatively with OGIS in both groups. There is a positive association between oxidative stress markers and 120-minute glucose in the prediabetes group. Insulin levels and HOMA-IR are positively related to plasma glucose and reciprocally to CV and M-Value in prediabetes, since the latter association is with borderline significance after adjustment for hypertension and smoking.

CONCLUSIONS

Our results demonstrate a significant correlation between oxidative stress and insulin resistance at early stages of glucose intolerance. Both chronic hyperglycemia and GV seem to be related to insulin levels and insulin resistance, and just postload glycaemia to oxidative stress in prediabetes.

Glycemic variability assessed by continuous glucose monitoring and the risk of diabetic retinopathy in latent autoimmune diabetes of the adult and type 2 diabetes

AIMS/INTRODUCTION

The relationship between glycemic variability (GV) and diabetic complications has gained much interest and remains under debate. Furthermore, the association of GV with diabetic complications has not been examined in latent autoimmune diabetes of the adult (LADA). Therefore, we evaluated the relationships among several metrics of GV with diabetic retinopathy (DR) in patients with LADA and type 2 diabetes mellitus.

MATERIALS AND METHODS

A total of 192 patients with LADA and 2,927 patients with type 2 diabetes mellitus were enrolled. After continuous glucose monitoring for 72 h, three metrics of GV including standard deviation, coefficient of variation and mean amplitude of glycemic excursions were calculated. DR was assessed by fundus photography performed with a digital non-mydriatic camera.

RESULTS

The prevalence of DR was 20.3 and 26.4% in LADA and type 2 diabetes mellitus patients (P < 0.001), respectively. Generally, LADA patients had fewer cardiometabolic risk factors than type 2 diabetes mellitus patients, and all GV metrics were significantly higher in LADA than in type 2 diabetes mellitus. In the multivariate logistic regression analysis, no metrics for GV were identified as independent risk factors of DR (standard deviation: P = 0.175; coefficient of variation: P = 0.769; mean amplitude of glycemic excursions: P = 0.388) in LADA. However, the standard deviation was significantly associated with DR (OR 1.15, P = 0.017) in patients with type 2 diabetes mellitus after adjusting for confounders. The independent relationships of coefficient of variation and mean amplitude of glycemic excursions with DR (P = 0.194 and P = 0.251, respectively) did not reach statistical significance in type 2 diabetes mellitus.

CONCLUSIONS

GV is more strongly associated with DR in type 2 diabetes than in LADA, suggesting that different glucose-lowering strategies should be used for these two types of diabetes.

Breakfast replacement with a liquid formula improves glycaemic variability in patients with type 2 diabetes: a randomised clinical trial

There is emerging evidence that glycaemic variability (GV) plays an important role in the development of diabetic complications. The current study aimed to compare the effects of lifestyle intervention (LI) with and without partial meal replacement (MR) on GV. A total of 123 patients with newly diagnosed and untreated type 2 diabetes (T2D) were randomised to receive either LI together with breakfast replacement with a liquid formula (LI+MR) (n 62) or LI alone (n 61) for 4 weeks and completed the study. Each participant was instructed to have three main meals per d and underwent 72-h continuous glucose monitoring (CGM) both before and after intervention. Measures of GV assessed by CGM included the incremental AUC of postprandial blood glucose (AUCpp), standard deviation of blood glucose (SDBG), glucose CV and mean amplitude of glycaemic excursions (MAGE). After a 4-week intervention, the improvements in systolic blood pressure (P=0·046) and time in range (P=0·033) were more pronounced in the LI+MR group than in the LI group. Furthermore, LI+MR caused significantly greater improvements in all GV metrics including SDBG (P=0·005), CV (P=0·002), MAGE (P=0·016) and AUCpp (P<0·001) than did LI. LI+MR (v. LI) was independently associated with improvements in GV after adjustment of covariates (all P<0·05). Our study showed that LI+MR led to significantly greater improvements in GV compared with LI, suggesting that LI+MR could be an effective treatment to alleviate glucose excursions.

Visit-to-Visit Variability of Hemoglobin A1c in People Without Diabetes and Risk of Major Adverse Cardiovascular Events and All-Cause Mortality

OBJECTIVE

We aimed to study whether visit-to-visit variability of glycated hemoglobin A_1c (HbA_1c) is associated with incident major adverse cardiovascular events (MACE), all-cause mortality, and type 2 diabetes in people without diabetes.

RESEARCH DESIGN AND METHODS

We included primary care patients with no history of diabetes or cardiovascular disease and with three annual HbA_1c measurements within normal range (<6.5% [48 mmol/mol]). For each individual, we measured the HbA_1c variability as the SD of the residuals obtained from a linear regression on the three HbA_1c measurements. From the linear regression, we also obtained the estimated index HbA_1c (intercept) and the trend over time (slope). Follow-up began at the date of the third measurement. Associations between HbA_1c variability and outcome were analyzed using Cox regression, adjusted for traditional risk factors, intercept, and trend and reported as hazard ratio per SD increase in variability (HR_SD).

RESULTS

In total, 6,756 individuals were included. During a median follow-up time of 6.3 years, 996 developed MACE, 856 died, and 1,267 developed type 2 diabetes. We found a significant association between increasing HbA_1c variability and incident MACE (HR_SD 1.09 [95% CI 1.03-1.15]) and all-cause mortality (HR_SD 1.13 [95% CI 1.07-1.20]), whereas there were no associations with type 2 diabetes (HR_SD 1.00 [95% CI 0.95-1.05]). We calculated 5-year absolute risks of MACE and all-cause mortality and found clinically relevant differences across several age, sex, comorbidity, and HbA_1c variability-defined subgroups.

CONCLUSIONS

In a primary care population free of diabetes and cardiovascular disease, high HbA_1c variability was associated with increased risks of MACE and all-cause mortality.

Normal High HbA1c a Risk Factor for Abnormal Pain Threshold in the Japanese Population

Purpose: Small fiber dysfunction is common in subjects with diabetic polyneuropathy (DPN). It is unsettled, however, whether marginal glucose intolerance is implicated in the onset and progression of small fiber dysfunction. Herein, we explored the relationship between glycated hemoglobin levels (HbA1c) and pain sensation in the Japanese population. Methods: A population-based study of 894 individuals (352 men, 542 women; average age 53.8 ± 0.5 years) and 55 subjects with impaired fasting glucose (IFG) in the 2017 Iwaki project were enrolled in this study. Individuals with diabetes were excluded. Relationships between pain threshold for intraepidermal electrical stimulation (P-IES) and parameters associated with metabolic syndrome were examined. Results: P-IES was elevated with increasing of age in women but not in men. Average P-IES (mA) was increased in IFG subjects (n = 55, 0.20 ± 0.03) compared with normoglycemic/non-IFG individuals (n = 894, 0.15 ± 0.11) (p < 0.01). It was comparable between IFG and a group of normal high HbA1c (5.9-6.4%). Univariate linear regression analyses showed no influence of sex, triglyceride, or cholesterol on the value of P-IES. In contrast, there were significant correlations between P-IES and serum HbA1c level (ß = 0.120, p < 0.001) Adjustments for the multiple clinical measurements confirmed positive correlation of P-IES with HbA1c (ß = 0.077, p = 0.046). Conclusion: Individuals with normal high HbA1c exhibited an elevated P-IES in a healthy Japanese population which may be useful for the screening of subclinical DPN.

Recurrent short-term hypoglycemia and hyperglycemia induce apoptosis and oxidative stress via the ER stress response in immortalized adult mouse Schwann (IMS32) cells

Hypoglycemia and fluctuating high or low glucose conditions are under-appreciated sources of oxidative stress contributing to diabetic neuropathy. We investigated the effects of recurrent short-term hypoglycemia and hyperglycemia, on apoptosis and oxidative stress in Schwann cells. Immortalized adult mouse Schwann (IMS32) cells were exposed to five different glucose treatments over 3 days: 1) normal glucose (NG), 2) constant low glucose (LG), 3) constant high glucose (HG), 4) intermittent low glucose (ILG; 1 h three times per day), 5) intermittent high glucose (IHG; 1 h three times per day). Cell viability was decreased by all treatment variants, in comparison to NG. Thiobarbituric acid reactive substance (TBARS) levels were increased by HG, LG, IHG, and ILG. High glucose (HG and IHG) and low glucose (LG and ILG) increased the expression of cleaved caspase-3 and reduced that of Bcl-2. In addition, endoplasmic reticulum (ER) stress-responsive transcription factor C/EBP homologous protein (CHOP) expression was increased under low and high glucose conditions. Cell death and oxidative stress induced by HG, LG, IHG, and ILG were significantly reduced by 4-phenyl butyric acid (4-PBA), an ER stress inhibitor. These findings indicate that recurrent short-term hypoglycemia and hyperglycemia induce apoptosis and oxidative stress via the ER stress response in Schwann cells.

Association of Time in Range, as Assessed by Continuous Glucose Monitoring, With Diabetic Retinopathy in Type 2 Diabetes

OBJECTIVE

Continuous glucose monitoring (CGM) has provided new measures of glycemic control that link to diabetes complications. This study investigated the association between the time in range (TIR) assessed by CGM and diabetic retinopathy (DR).

RESEARCH DESIGN AND METHODS

A total of 3,262 patients with type 2 diabetes were recruited. TIR was defined as the percentage of time spent within the glucose range of 3.9-10.0 mmol/L during a 24-h period. Measures of glycemic variability (GV) were assessed as well. DR was determined by using fundus photography and graded as 1) non-DR; 2) mild nonproliferative DR (NPDR); 3) moderate NPDR; or 4) vision-threatening DR (VTDR).

RESULTS

The overall prevalence of DR was 23.9% (mild NPDR 10.9%, moderate NPDR 6.1%, VTDR 6.9%). Patients with more advanced DR had significantly less TIR and higher measures of GV (all P for trend <0.01). The prevalence of DR on the basis of severity decreased with ascending TIR quartiles (all P for trend <0.001), and the severity of DR was inversely correlated with TIR quartiles (r = -0.147; P < 0.001). Multinomial logistic regression revealed significant associations between TIR and all stages of DR (mild NPDR, P = 0.018; moderate NPDR, P = 0.014; VTDR, P = 0.019) after controlling for age, sex, BMI, diabetes duration, blood pressure, lipid profile, and HbA_1c. Further adjustment of GV metrics partially attenuated these associations, although the link between TIR and the presence of any DR remained significant.

CONCLUSIONS

TIR assessed by CGM is associated with DR in type 2 diabetes.

A pyridoindole antioxidant SMe1EC2 regulates contractility, relaxation ability, cation channel activity, and protein-carbonyl modifications in the aorta of young and old rats with or without diabetes mellitus

We studied the effects of treatment with SMe1EC, a hexahydropyridoindole antioxidant, on vascular reactivity, endothelial function, and oxidonitrosative stress level of thoracic aorta in young and old rats with or without diabetes mellitus. The rats were grouped as young control (YC 3 months old), old control (OC 15 months old), young diabetic (YD), old diabetic (OD), young control treated (YCT), old control treated (OCT), young diabetic treated (YDT), and old diabetic treated (ODT). Diabetes was induced by streptozotocin injection and subsequently SMe1EC2 (10 mg/kg/day, p.o.) was administered to YCT, OCT, YDT, and ODT rats for 5 months. In young and old rats, diabetes resulted in hypertension, weight loss, hyperglycemia, and hypertriglyceridemia, which were partially prevented by SMe1EC2. SMe1EC2 also inhibited the diabetes-induced increase in aorta levels of AGEs (advanced glycosylation end-protein adducts), 4-HNE (4-hydroxy-nonenal-histidine), 3-NT (3-nitrotyrosine), and RAGEs (receptors for AGEs). The contractions of the aorta rings to phenylephrine (Phe) and KCL did not significantly change, but acetylcholine (ACh) and salbutamol relaxations were reduced in OC compared to YC rats. Diabetes induction increased Phe contractions in YC and OC rats, KCL contractions in YC rats, and did not cause further inhibition in already inhibited ACh and salbutamol relaxations in OC rats. We have achieved the lowest levels of ACh relaxation in YD rats compared to other groups. SMe1EC2 did not change the response of aorta to ACh, salbutamol and Phe in YC rats, and ameliorated ACh relaxations in OC and YD but not in OD rats. In YDT and ODT rats, increased Phe and KCL contractions, high blood pressure, and impaired salbutamol relaxations were amended by SMe1EC2. Phe contractions observed in YD and OD rats as well as KCl contractions observed in OC rats were the lowest levels when the rats were treated with SMe1EC2. When the bath solution was shifted to cyclopiazonic acid (CYP) or CYP plus Ca²⁺-free medium, the contraction induced by a single dose of Phe (3 × 10^-6 M) was more inhibited in YD and OD than in YC but not in OC rats. In SMe1EC2-treated rats, neither the presence of CFM nor CFM plus CYP exhibited a significant change in response of aorta to a single dose of Phe. These findings suggest that α1-adrenergic receptor signaling is activated in both age groups of diabetic rats, diabetes activates K⁺-depolarization and calcium mobilization via Ca_V especially in the aorta of young rats, and sensitizes the aorta of old rats to the regulating effect of SMe1EC2. ACh relaxations were inhibited in YC rats, increased in OC rats and unchanged in YD and OD rats when aortic rings pretreated with TEA, an inhibitor of calcium-activated K⁺ channels (K_Ca), or 4-aminopyridine (4-AP), an inhibitor of voltage-sensitive K⁺ channels (K_V). ACh relaxations were inhibited in YCT, OCT, and YDT rats in the presence of 4-AP or TEA. In ODT rats, 4-AP did not change ACh relaxation but TEA inhibited. These findings suggest that the contribution of K_v and K_Ca to ACh relaxation is likely upregulated by SMe1EC2 when the relaxations were inhibited by aging or diabetes. We conclude that SMe1EC2 might be a promising agent for aging and diabetes related vascular disorders.

Nonfasting Glucose and Incident Stroke and Its Types - The Circulatory Risk in Communities Study (CIRCS)

BACKGROUND

The effect of postprandial glucose on the risk of cardiovascular disease has been emphasized, but it is controversial whether nonfasting glucose is related to incident stroke and its types.Methods and Results:We investigated the associations of nonfasting glucose with incident stroke and its types among 7,198 participants aged 40-74 years from the Circulatory Risk in Communities Study, enrolled in 1995-2000. We estimated multivariable hazard ratios (HR) using Cox proportional hazard models. Over a median follow-up of 14.1 years, 291 cases of total stroke (ischemic strokes: 191 including 109 lacunar infarctions) were identified. Nonfasting glucose concentration was associated with greater risk of incident total stroke, ischemic stroke and lacunar infarction when modeled categorically (for prediabetic type: 7.8-11.0 mmol/L vs. normal type: <7.8 mmol/L among all subjects, HR for lacunar infarction was 2.02, 95% confidence interval (CI): 1.19, 3.43) or continuously (per one standard deviation increment among all subjects, HR for lacunar infarction was 1.29, 95% CI: 1.15, 1.45). Diabetic type showed similar results. Population attributable fractions of nonfasting hyperglycemia were 13.2% for ischemic stroke and 17.4% for lacunar infarction.

CONCLUSIONS

Nonfasting glucose concentration, either as a diagnosis of prediabetic and diabetic types or as a continuous variable, proved to be an independent predictor significantly attributed to incident total stroke, especially ischemic stroke and lacunar infarction, in the general population.

Integration of Routine Parameters of Glycemic Variability in a Simple Screening Method for Partial Remission in Children with Type 1 Diabetes

Although different criteria were used to define partial remission in type 1 diabetes, the IDAA1C formula has prevailed as it correlates with stimulated C-peptide levels. Our retrospective study evaluated clinical variables associated with the occurrence of IDAA1C-defined partial remission in a series of 239 pediatric patients. Diabetic ketoacidosis and age at diagnosis, but no other clinical feature, influenced the occurrence of remission. We then evaluated whether parameters of glycemic variability used in clinical routine may reliably define partial remission, as these would alleviate confounding factors related to insulin treatment. Using multiple linear regression, we observed that HbA_1C levels and percentage of normoglycemia were efficient and sufficient to predict partial remission. These parameters were entered into a formula, called glycemic target-adjusted HbA_1C (GTAA_1C), that corresponded to HbA_1C(%) - (3 × % of normoglycemic values_{(70-180 mg/dL)}). With a threshold of 4.5, this alternative formula predicted partial remission with a sensitivity and a specificity of 72.3% and 92%, respectively, and yielded strong correlation with IDAA1C levels and BETA-2 score, which is a correlate of β-cell function after islet transplantation. We propose GTAA_1C, based on routine and objective markers of glycemic variability, as a valid alternative for definition of partial remission in type 1 diabetes.

Visit-to-Visit Variability of Fasting Plasma Glucose and the Risk of Cardiovascular Disease and All-Cause Mortality in the General Population

Background

The association of short‐term variability of fasting plasma glucose (FPG) and mortality has been well investigated. However, the relationships between visit‐to‐visit variability of FPG over longer periods of follow‐up and cardiovascular disease (CVD) and all‐cause mortality are unclear. This study aimed to investigate these relationships.

Methods and Results

The current analysis included 53 607 Chinese participants (mean age, 49.10 years) who were free of CVD in the Kailuan study. Participants were divided into 4 categories by quartiles of visit‐to‐visit variability of FPG. Visit‐to‐visit variability of FPG was defined as the coefficient of variation of 3 values of FPG that were measured from the examination periods of 2006 to 2007, 2008 to 2009, and 2010 to 2011. Cox proportional hazards models were used to calculate hazard ratios and 95% confidence intervals for CVD and all‐cause mortality. After a mean follow‐up of 4.93 years, 4261 individuals developed CVD and 1545 individuals died. The incidence of CVD and all‐cause mortality was 5.04 and 5.85 per 1000 person‐years, respectively. After adjusting for mean FPG and other potential confounders, individuals in the highest quartile of variability of FPG compared with participants in the lowest quartile showed a 26% greater risk of developing CVD (hazard ratio, 1.26; 95% confidence interval, 1.08–1.47) and a 46% greater risk for all‐cause mortality (hazard ratio, 1.46; 95% confidence interval, 1.25–1.70).

Conclusions

Independent of mean FPG and other baseline parameters, elevated visit‐to‐visit variability of FPG significantly increases the risk of CVD and all‐cause mortality in the general population. Measuring long‐term visit‐to‐visit variability of FPG is helpful for predicting the risk for CVD and all‐cause mortality.