Cardiovascular Implications of Hypoglycemia in Diabetes Mellitus

Accuracy of Continuous Glucose Monitoring in Hemodialysis Patients With Diabetes

OBJECTIVE

In the general population, continuous glucose monitoring (CGM) provides convenient and less-invasive glucose measurements than conventional self-monitored blood glucose and results in reduced hypoglycemia and hyperglycemia and increased time in target glucose range. However, accuracy of CGM versus blood glucose is not well established in hemodialysis patients.

RESEARCH DESIGN AND METHODS

Among 31 maintenance hemodialysis patients with diabetes hospitalized from October 2020 to May 2021, we conducted protocolized glucose measurements using Dexcom G6 CGM versus blood glucose, with the latter measured before each meal and at night, plus every 30-min during hemodialysis. We examined CGM-blood glucose correlations and agreement between CGM versus blood glucose using Bland-Altman plots, percentage of agreement, mean and median absolute relative differences (ARDs), and consensus error grids.

RESULTS

Pearson and Spearman correlations for averaged CGM versus blood glucose levels were 0.84 and 0.79, respectively; Bland-Altman showed the mean difference between CGM and blood glucose was ∼+15 mg/dL. Agreement rates using %20/20 criteria were 48.7%, 47.2%, and 50.2% during the overall, hemodialysis, and nonhemodialysis periods, respectively. Mean ARD (MARD) was ∼20% across all time periods; median ARD was 19.4% during the overall period and was slightly lower during nonhemodialysis (18.2%) versus hemodialysis periods (22.0%). Consensus error grids showed nearly all CGM values were in clinically acceptable zones A (no harm) and B (unlikely to cause significant harm).

CONCLUSIONS

In hemodialysis patients with diabetes, although MARD values were higher than traditional optimal analytic performance thresholds, error grids showed nearly all CGM values were in clinically acceptable zones. Further studies are needed to determine whether CGM improves outcomes in hemodialysis patients.

Association between fasting stress hyperglycemia ratio and contrast-induced acute kidney injury in coronary angiography patients: a cross-sectional study

Aims

Stress hyperglycemia ratio (SHR), an emerging indicator of critical illness, exhibits a significant association with adverse cardiovascular outcomes. The primary aim of this research endeavor is to evaluate the association between fasting SHR and contrast-induced acute kidney injury (CI-AKI).

Methods

This cross-sectional study comprised 3,137 patients who underwent coronary angiography (CAG) or percutaneous coronary intervention (PCI). The calculation of fasting SHR involved dividing the admission fasting blood glucose by the estimated mean glucose obtained from glycosylated hemoglobin. CI-AKI was assessed based on elevated serum creatinine (Scr) levels. To investigate the relationship between fasting SHR and the proportion of SCr elevation, piecewise linear regression analysis was conducted. Modified Poisson's regression analysis was implemented to evaluate the correlation between fasting SHR and CI-AKI. Subgroup analysis and sensitivity analysis were conducted to explore result stability.

Results

Among the total population, 482 (15.4%) patients experienced CI-AKI. Piecewise linear regression analysis revealed significant associations between the proportion of SCr elevation and fasting SHR on both sides (≤ 0.8 and > 0.8) [β = -12.651, 95% CI (-23.281 to -2.022), P = 0.020; β = 8.274, 95% CI (4.176 to 12.372), P < 0.001]. The Modified Poisson's regression analysis demonstrated a statistically significant correlation between both the lowest and highest levels of fasting SHR and an increased incidence of CI-AKI [(SHR < 0.7 vs. 0.7 ≤ SHR < 0.9) β = 1.828, 95% CI (1.345 to 2.486), P < 0.001; (SHR ≥ 1.3 vs. 0.7 ≤ SHR < 0.9) β = 2.896, 95% CI (2.087 to 4.019), P < 0.001], which was further validated through subgroup and sensitivity analyses.

Conclusion

In populations undergoing CAG or PCI, both lowest and highest levels of fasting SHR were significantly associated with an increased occurrence of CI-AKI.

Population Pharmacokinetic Model of N-Acetylcysteine During Periods of Recurrent Hypoglycemia in Healthy Volunteers

Recurrent hypoglycemia leads to impaired awareness of hypoglycemia where the blood glucose threshold that elicits the counterregulatory response is lowered. Hypoglycemia-induced oxidative stress is hypothesized to contribute to impaired awareness of hypoglycemia development and hypoglycemia-associated autonomic failure. Our group conducted a randomized, double-blinded, placebo-controlled, crossover study in healthy individuals undergoing experimentally induced recurrent hypoglycemia to evaluate the impact of intravenous N-acetylcysteine (NAC) during experimental hypoglycemia to preserve the counterregulatory response to subsequent hypoglycemia. The work presented herein aimed to characterize the NAC pharmacokinetics and its effects on oxidative stress. Whole blood and plasma samples were collected at specified time points during separate NAC and placebo infusions from 10 healthy volunteers. Samples were analyzed for NAC, cysteine, and glutathione (GSH) concentrations. A 2-compartment population NAC pharmacokinetic model was developed. Estimates for central compartment clearance and volume of distribution were 19.8 L/h, and 12.2 L, respectively, for a 70-kg person. Peripheral compartment clearance and volume of distribution estimates were 34.9 L/h and 13.1 L, respectively, for a 70-kg person. The PK parameters estimated here were different from those reported in the literature, suggesting a higher NAC clearance during hypoglycemic episodes. NAC leads to a significant increase in circulating cysteine concentration in a NAC concentration-dependent manner, suggesting rapid biotransformation. A transient decrease in plasma GSH was observed, supporting the hypothesis that NAC can act as a reducing agent displacing glutathione from the disulfide bond allowing for increased clearance and/or distribution of GSH.

Role of continuous glucose monitoring in diabetic patients at high cardiovascular risk: an expert-based multidisciplinary Delphi consensus

Background

Continuous glucose monitoring (CGM) shows in more detail the glycaemic pattern of diabetic subjects and provides several new parameters (“glucometrics”) to assess patients’ glycaemia and consensually guide treatment. A better control of glucose levels might result in improvement of clinical outcome and reduce disease complications. This study aimed to gather an expert consensus on the clinical and prognostic use of CGM in diabetic patients at high cardiovascular risk or with heart disease.

Methods

A list of 22 statements concerning type of patients who can benefit from CGM, prognostic impact of CGM in diabetic patients with heart disease, CGM use during acute cardiovascular events and educational issues of CGM were developed. Using a two-round Delphi methodology, the survey was distributed online to 42 Italian experts (21 diabetologists and 21 cardiologists) who rated their level of agreement with each statement on a 5-point Likert scale. Consensus was predefined as more than 66% of the panel agreeing/disagreeing with any given statement.

Results

Forty experts (95%) answered the survey. Every statement achieved a positive consensus. In particular, the panel expressed the feeling that CGM can be prognostically relevant for every diabetic patient (70%) and that is clinically useful also in the management of those with type 2 diabetes not treated with insulin (87.5%). The assessment of time in range (TIR), glycaemic variability (GV) and hypoglycaemic/hyperglycaemic episodes were considered relevant in the management of diabetic patients with heart disease (92.5% for TIR, 95% for GV, 97.5% for time spent in hypoglycaemia) and can improve the prognosis of those with ischaemic heart disease (100% for hypoglycaemia, 90% for hyperglycaemia) or with heart failure (87.5% for hypoglycaemia, 85% for TIR, 87.5% for GV). The experts retained that CGM can be used and can impact the short- and long-term prognosis during an acute cardiovascular event. Lastly, CGM has a recognized educational role for diabetic subjects.

Conclusions

According to this Delphi consensus, the clinical and prognostic use of CGM in diabetic patients at high cardiovascular risk is promising and deserves dedicated studies to confirm the experts’ feelings.

Antidiabetic Activity of Xoconostle Fruit from Opuntia matudae Scheivar in Mice

In Mexico, Cactaceae plants are widely used in folk medicine for the treatment of diabetes. The genus Opuntia spp. Opuntia matudae Sheinvar prickly pears are known as xoconostle and are used in Mexican cuisine for their acidic flavor. Currently there are few reports of pharmacological properties of this plant, which include antioxidant and antimicrobial activities. This study focuses on the chemical characterization of the methanolic (OmMe) and aqueous (OmAq) extracts and the evaluation of the antidiabetic activity of O. matudae fruits in two biological models. For the in vivo model, streptozotocin (STZ)-induced diabetic mice were used, and for the in vitro model, liver sections isolated from healthy mice were used. The OmAq (100 mg/kg, oral pathway [p.o.]) extract decreased postprandial glucose peak at 0.5 h after glucose uptake by 43.1%, similarly, OmMe (100 mg/kg, p.o.) extract reduced postprandial glucose peak at 0.5 h by 34.1% in healthy mice. The effect of the two extracts and the fraction of the mixture of unidentified betalains (OmB) of O. matudae evaluated in the isolated mouse liver slice model showed a concentration-dependent decrease in hepatic glucose output (HGO) with and without insulin administration with the OmMe extract. The OmAq extract, however, showed concentration-dependent increases of HGO with and without insulin, and the OmB fraction generally exhibited an insulin mimetic effect. Moreover, both OmAq and OmMe extracts were tested in mice with STZ-induced diabetes (160 mg/kg, intraperitoneal route), using a semichronic daily administration (2-28 days after diabetes onset) of OmAq extract was able to reduce blood glucose by 34.3%, meanwhile OmMe extract reduced blood glucose by 22.9%, 28 days after diabetes onset. We identified five compounds (1-5) in the two extracts, consisting of two phenolic acids (1, 2), three flavanols (3-5), as well as two unidentified betalains. Therefore, we conclude that the aqueous extract of the xoconostle fruit where betalains are present may be useful for the treatment of diabetes mellitus.

Metformin-Insulin versus Metformin-Sulfonylurea Combination Therapies in Type 2 Diabetes: A Comparative Study of Glycemic Control and Risk of Cardiovascular Diseases in Addis Ababa, Ethiopia

OBJECTIVE

This study aimed to compare glycemic control and risk of cardiovascular outcomes of metformin-insulin versus metformin-sulfonylurea combination therapies in type 2 diabetes mellitus.

METHODS

We conducted a comparative cross-sectional study in five tertiary level hospitals in Addis Ababa, Ethiopia. We enrolled 321 patients with type 2 diabetes mellitus who were on continuous treatment follow-up on either metformin-insulin or metformin-sulfonylurea combination therapy. We interviewed the participants and reviewed their medical records to investigate medication efficacy, safety, and adherence. The primary outcome measure was glycemic control and the secondary outcome measures were composite cardiovascular outcomes.

RESULTS

Of the total participants enrolled, 50.5% (n = 162) were those who received metformin-insulin and 49.5% (n = 159) metformin-sulfonylurea combination therapies for a median of 48 months follow-up. The reduction of Hb1Ac levels was comparable between the metformin-insulin (-1.04 ± 0.96%) and metformin-sulfonylurea (-1.02 ± 1.03%), p = 0.912. Patients who received metformin-sulfonylurea had 4.3 times more likely to have achieved target HbA1c level compared to those who received metformin-insulin, p < 0.001, adjusted odds ratio (AOR) with 95% CI = 4.31[1.79-10.32]. Risk of composite cardiovascular outcomes was higher in metformin-insulin group (40.5% versus 34.0%), p = 0.021. Co-morbidities, body mass index, systolic blood pressure, and HbA1c had a significant association with composite cardiovascular outcomes. Reductions of bodyweight, HDL-C, LDL-C, triglycerides levels, and microvascular complications were different between the two groups, p < 0.05.

CONCLUSION

High proportion of patients who received metformin-sulfonylurea achieved target HbA1c level and had less composite cardiovascular outcomes compared to those who received metformin-insulin. However, these findings have to be confirmed with randomized control trials to determine risks associated with insulin use, while efficacy is maintained as second-line treatment in patients with type 2 diabetes mellitus.

The Protective Effect of Tetrahydroxystilbene Glucoside on High Glucose-Induced Injury in Human Umbilical Vein Endothelial Cells through the PI3K/Akt/eNOS Pathway and Regulation of Bcl-2/Bax

Endothelial dysfunction plays a central role in the patho-genesis of diabetic vascular complications. 2,3,5,4'-tetra-hydroxystilbene-2-O-β-D-glucoside (TSG), an active component extracted from the roots of Polygonum multiflorum Thunb, has been shown to have strong antioxidant and antiapoptotic activities. In the present study, we investigated the protective effect of TSG on apoptosis induced by high glucose in human umbilical vein endothelial cells (HUVECs) and the possible mechanisms. Our data demonstrated that TSG significantly reversed the high glucose-induced decrease in cell viability, suppressed high glucose-induced generation of intracellular reactive oxygen species (ROS), the activity of caspase-3, and decreased the percentage of apoptotic cells in a dose-dependent manner. In addition, we found that TSG not only increased the expression of Bcl-2, while decreasing Bax expression, but also activated phosphorylation of Akt and endothelial nitric oxide synthase (eNOS) with subsequent nitric oxide production and ultimately reduced high glucose-induced apoptosis. However, the antiapoptotic effects of TSG were abrogated by pretreatment of the cells with PI3K inhibitor (LY294002) or eNOS inhibitor NG-L-nitro-arginine methyl ester, respectively. These results suggest that TSG inhibits high glucose-induced apoptosis in HUVECs through inhibition of ROS production, activation of the PI3K/Akt/eNOS pathway, and upregulation of the Bcl-2/Bax ratio, and thus may demonstrate significant potential for preventing diabetic cardiovascular complications.

Effects of SGLT2 Inhibitors on Kidney and Cardiovascular Function

SGLT2 inhibitors are antihyperglycemic drugs that protect kidneys and the heart of patients with or without type 2 diabetes and preserved or reduced kidney function from failing. The involved protective mechanisms include blood glucose-dependent and -independent mechanisms: SGLT2 inhibitors prevent both hyper- and hypoglycemia, with expectedly little net effect on HbA1C. Metabolic adaptations to induced urinary glucose loss include reduced fat mass and more ketone bodies as additional fuel. SGLT2 inhibitors lower glomerular capillary hypertension and hyperfiltration, thereby reducing the physical stress on the filtration barrier, albuminuria, and the oxygen demand for tubular reabsorption. This improves cortical oxygenation, which, together with lesser tubular gluco-toxicity, may preserve tubular function and glomerular filtration rate in the long term. SGLT2 inhibitors may mimic systemic hypoxia and stimulate erythropoiesis, which improves organ oxygen delivery. SGLT2 inhibitors are proximal tubule and osmotic diuretics that reduce volume retention and blood pressure and preserve heart function, potentially in part by overcoming the resistance to diuretics and atrial-natriuretic-peptide and inhibiting Na-H exchangers and sympathetic tone.

Glucose variability and diabetes complications: Risk factor or biomarker? Can we disentangle the "Gordian Knot"?

« Variability in glucose homoeostasis » is a better description than « glycaemic variability » as it encompasses two categories of dysglycaemic disorders: i) the short-term daily glucose fluctuations and ii) long-term weekly, monthly or quarterly changes in either HbA1c, fasting or postprandial plasma glucose. Presently, the relationship between the "variability in glucose homoeostasis" and diabetes complications has never been fully clarified because studies are either observational or limited to retrospective analysis of trials not primarily designed to address this issue. Despite the absence of definitive evidence from randomized controlled trials (RCTs), it is most likely that acute and long-term glucose homoeostasis "cycling", akin to weight and blood pressure "cycling" in obese and hypertensive individuals, are additional risk factors for diabetes complications in the presence of sustained ambient hyperglycaemia. As hypoglycaemic events are strongly associated with short- and long-term glucose variability, two relevant messages can be formulated. Firstly, due consideration should be given to avoid within-day glucose fluctuations in excess of 36% (coefficient of variation) at least for minimizing the inconvenience and dangers associated with hypoglycaemia. Secondly, it seems appropriate to consider that variability in glucose homoeostasis is not only associated with cardiovascular events but is also a causative risk factor via hypoglycaemic episodes as intermediary step. Untangling the" Gordian Knot", to provide confirmation about the impact of variability in glucose homoeostasis and diabetes complications remains a daunting prospect.

Sodium-glucose cotransporter 2 inhibitors and type 2 diabetes: clinical pearls for in-hospital initiation, in-hospital management, and postdischarge

PURPOSE OF REVIEW

The aim of this article is to provide practical recommendations on safe initiation of sodium-glucose cotransporter 2 (SGLT2) inhibitors to in-patients as well as management of those who are already on SGLT2 inhibitors.

RECENT FINDINGS

Robust data from stable outpatient cohorts indicate that the SGLT2 inhibitors are associated with clinically meaningful reductions in major adverse cardiovascular events, lower rates of hospitalization for heart failure, and a reduction in major kidney outcomes There is however a lack of information on how to initiate and manage SGLT2 inhibitors in an acute in-patient setting.

SUMMARY

SGLT2 inhibitors may be cautiously appropriate for in-patients if all the criteria for safe use are met but good clinical judgment must prevail. Temporary withholding of SGLT2 inhibitors is appropriate in hospitalized patients during a period of stress and/or insulinopenia.

Network Pharmacology-Based Identification of the Mechanisms of Shen-Qi Compound Formula in Treating Diabetes Mellitus

Aim

The purpose of this research is to identify the mechanisms of Shen-Qi compound formula (SQC), a traditional Chinese medicine (TCM), for treating diabetes mellitus (DM) using system pharmacology.

Methods

The active components and therapeutic targets were identified, and these targets were analyzed using gene ontology (GO) enrichment analysis, Kyoto Encyclopedia of Genes and Genomes (KEGG) enrichment analysis, and protein-protein interaction (PPI) analysis. Finally, an integrated pathway was constructed to show the mechanisms of SQC.

Results

A total of 282 active components and 195 targets were identified through a database search. The component-target network was constructed, and the key components were screened out according to their degree. Through the GO, PPI, and KEGG analyses, the mechanism network of SQC treating DM was constructed.

Conclusions

This study shows that the mechanisms of SQC treating DM are related to various pathways and targets. This study provides a good foundation and basis for further in-depth verification and clinical application.

Hypoglycemia in Older Patients

Hypoglycemia is a serious problem in older patients with diabetes mellitus. This chapter discusses risk factors associated with hypoglycemia and approaches to mitigation of the risk for hypoglycemia. Specific considerations include selection of glucose lowering agents, comorbid conditions and the implications of declining cognitive dysfunction.

Confirming the Bidirectional Nature of the Association Between Severe Hypoglycemic and Cardiovascular Events in Type 2 Diabetes: Insights From EXSCEL

OBJECTIVE

We sought to confirm a bidirectional association between severe hypoglycemic events (SHEs) and cardiovascular (CV) event risk and to characterize individuals at dual risk.

RESEARCH DESIGN AND METHODS

In a post hoc analysis of 14,752 Exenatide Study of Cardiovascular Event Lowering (EXSCEL) participants, we examined time-dependent associations between SHEs and subsequent major adverse cardiac events (CV death, nonfatal myocardial infarction [MI] or stroke), fatal/nonfatal MI, fatal/nonfatal stroke, hospitalization for acute coronary syndrome (hACS), hospitalization for heart failure (hHF), and all-cause mortality (ACM), as well as time-dependent associations between nonfatal CV events and subsequent SHEs.

RESULTS

SHEs were uncommon and not associated with once-weekly exenatide therapy (hazard ratio 1.13 [95% CI 0.94-1.36], P = 0.179). In fully adjusted models, SHEs were associated with an increased risk of subsequent ACM (1.83 [1.38-2.42], P < 0.001), CV death (1.60 [1.11-2.30], P = 0.012), and hHF (2.09 [1.37-3.17], P = 0.001), while nonfatal MI (2.02 [1.35-3.01], P = 0.001), nonfatal stroke (2.30 [1.25-4.23], P = 0.007), hACS (2.00 [1.39-2.90], P < 0.001), and hHF (3.24 [1.98-5.30], P < 0.001) were all associated with a subsequent increased risk of SHEs. The elevated bidirectional time-dependent hazards linking SHEs and a composite of all CV events were approximately constant over time, with those individuals at dual risk showing higher comorbidity scores compared with those without.

CONCLUSIONS

These findings, showing greater risk of SHEs after CV events as well as greater risk of CV events after SHEs, validate a bidirectional relationship between CV events and SHEs in patients with high comorbidity scores.

Hypoglycaemic episodes increase the risk of ventricular arrhythmia and sudden cardiac arrest in patients with type 2 diabetes-A nationwide cohort study

BACKGROUND

The impact of hypoglycaemic episode (HE) on the risk of ventricular arrhythmia (VA) and sudden cardiac arrest (SCA) remains unclear. We hypothesized that HE increases the risk of both VA and SCA and that glucose-lowering agents causing HE also increase the risk of VA/SCA in patients with type 2 diabetes (T2D).

METHODS

Patients aged 20 years or older with newly diagnosed T2D were identified using the Taiwan National Health Insurance Database. HE was defined as the presentation of hypoglycaemic coma or specified/unspecified hypoglycaemia. The control group consisted of T2D patients without HE. The primary outcome was the occurrence of VA (including ventricular tachycardia and fibrillation) and SCA during the defined follow-up periods. A multivariate Cox hazards regression model was used to evaluate the hazard ratio (HR) for VA or SCA.

RESULTS

A total of 54 303 patients were screened, with 1037 patients with HE assigned to the HE group and 4148 frequency-matched patients without HE constituting the control group. During a mean follow-up period of 3.3 ± 2.5 years, 29 VA/SCA events occurred. Compared with the control group, HE group had a higher incidence of VA/SCA (adjusted HR: 2.42, P = .04). Patients who had used insulin for glycaemic control showed an increased risk of VA/SCA compared with patients who did not receive insulin (adjusted HR: 3.05, P = .01).

CONCLUSIONS

The HEs in patients with T2D increased the risk of VA/SCA, compared with those who did not experience HEs. Use of insulin also independently increased the risk of VA/SCA.

Effects of sodium-glucose cotransporter-2 inhibitors on the cardiovascular and renal complications of type 2 diabetes

Sodium-glucose cotransporter-2 inhibitors (SGLT-2is) have been shown to mitigate the risks of cardiovascular (CV) and renal complications in patients with type 2 diabetes (T2D) and CV risk factors or CV disease (CVD). In CV outcomes trials (CVOTs) of patients with T2D and established CVD or multiple CV risk factors, empagliflozin and canagliflozin were associated with significant reductions in the risks of major adverse CV events (MACE), hospitalization for heart failure (HF) and kidney disease progression. In the DECLARE-TIMI 58 study, in which the majority of patients did not have established CVD, dapagliflozin was associated with significant reductions in the composite end point of CV death or hospitalization for HF and was noninferior to placebo with regard to MACE; although patients had relatively good renal function, dapagliflozin also showed renal benefits similar to those seen with empagliflozin and canagliflozin. This article reviews the increased risk of CVD and renal disease in patients with T2D and discusses the potential mechanisms of the cardioprotective and renoprotective effects of SGLT-2i therapy. The observed improvements in CV and renal outcomes with SGLT-2is in CVOTs suggest a class effect in this patient population and have influenced treatment guidelines for the way add-on therapy to metformin is initiated in patients with T2D and high CV risk. The overall cardioprotective and renoprotective effects of SGLT-2is in patients with T2D and high CV risk are most likely attributable to multiple mechanisms, including cardiac, haemodynamic, metabolic, anti-inflammatory and renal effects.

Severe hypoglycemia and the risk of cardiovascular disease and mortality in type 2 diabetes: a nationwide population-based cohort study

BACKGROUND

We investigated the association regarding severe hypoglycemia episodes with cardiovascular disease risk and all-cause mortality in patients with type 2 diabetes.

METHODS

Baseline and follow-up data (n = 1,568,097) from patients with type 2 diabetes were retrieved from the National Health Insurance System database (covering the entire Korean population). Type 2 diabetes, severe hypoglycemia, and major comorbidities were identified using International Classification of Diseases 10 codes and medication information. Individuals who were classified as type 2 diabetes in the year of 2009 were screened, and we counted severe hypoglycemia episodes from 2007 to 2009. The primary outcome was newly developed myocardial infarction (MI), stroke, heart failure, or all-cause mortality. Participants were followed from the baseline index date to the date of death or until December 31, 2015.

RESULTS

In total, 19,660 (1.2%) patients developed at least one severe hypoglycemia event during the period from 2007 to 2009. Mean follow-up was 5.7 years. After adjustment for confounding factors, the hazard ratio (HR) of MI significantly and sequentially increased: 0 vs. 1 episode, HR 1.56, 95% CI 1.46-1.64; 0 vs. 2 episodes, HR 1.86, 95% CI 1.61-2.15; 0 vs. 3 or more episodes, HR 1.86, 95% CI 1.48-2.35, P for trend < 0.001. Similar findings were noted regarding the relationship of severe hypoglycemia episodes with stroke, heart failure, and all-cause mortality. Risks for all outcomes were highest within 1 year from the index date and showed decreasing trends with follow-up. Sensitivity analyses of the data from the subgroup population and 797,544 subjects who received a national health examination did not change the significance of the main findings.

CONCLUSION

Among adult Korean patients with type 2 diabetes, a severe hypoglycemia episode is associated with increased risk for cardiovascular outcomes and all-cause mortality. Significant results from dose-response, temporal, and sensitivity analyses may suggest the possibility of direct causality between severe hypoglycemia and cardiovascular outcomes and mortality.

Efficacy and short-term side effects of sitagliptin, vildagliptin and saxagliptin in Chinese diabetes: a randomized clinical trial

AIMS

To investigate the difference in the efficacy among dipeptidyl peptidase-4 (DPP-4) inhibitors in Chinese adults with newly diagnosed diabetes.

MATERIALS AND METHODS

In a multicenter, randomized study, we enrolled adults who were either treatment naive or off prior anti-hyperglycemic therapy for at least 3 months. Eligible patients had hemoglobin A1c (HbA1c) concentrations of 6.5-9.5%. Three hundred patients had been randomly allocated to sitagliptin 100 mg, once daily; vildagliptin 50 mg, twice daily and saxagliptin 5 mg, once daily for 12 weeks. Patients and investigators were masked to treatment assignment. The primary endpoint was change from baseline in HbA1c at week 12. This study was completed and registered with ClinicalTrials.gov, number NCT01703637.

RESULTS

Totally 277 patients were enrolled in the final analysis, and 93 patients received sitagliptin, 94 received vildagliptin and 90 received saxagliptin. Compared with baseline, adjusted mean differences in change from baseline HbA1c at week 12 were -0.50% (95% CI: -0.20 to -0.90), -0.65% (95% CI: -0.40 to -1.40), -0.70 (95% CI: -0.50 to -1.00) for sitagliptin, vildagliptin and saxagliptin group, respectively. The overall HbA1c-lowering effect was similar for all three selected DPP-4 inhibitors after adjustment for age and baseline HbA1c. Notably, in secondary outcome analysis, patients in vildagliptin group showed a significant decrease in total cholesterol levels, compared with participants in sitagliptin and saxagliptin groups. No significant between-group difference was shown in adverse events (AE).

CONCLUSIONS

The overall HbA1c-lowering effect and incidence of AE were similar for sitagliptin, vildagliptin and saxagliptin in Chinese adults with newly diagnosed diabetes.

Glucose Lowering Strategies for Cardiac Benefits: Pathophysiological Mechanisms

Recent trials in Type 2 diabetes (T2D) have shown cardiovascular benefits with specific GLP-1 receptor agonists and SGLT2 inhibitors. We discuss the landscape of outcome trials in T2D from a pathophysiology viewpoint, review current knowledge gaps in underlying mechanisms, propose a caloric fuel routing hypothesis, and highlight areas of future research.

Glycaemic control and mortality in older people with type 2 diabetes: The Fremantle Diabetes Study Phase II

AIM

To investigate whether tight glycaemic control achieved with metformin, insulin or sulphonylurea-based pharmacotherapy increases all-cause mortality in older people with type 2 diabetes.

MATERIALS AND METHODS

We conducted a prospective cohort study of individuals with known diabetes recruited between 2008 and 2011 and followed until 2016. The impact of baseline glycated haemoglobin (HbA1c) on mortality hazards was investigated in participants aged ≥75 years. Proportional hazards models for time to death were constructed from the baseline clinical assessment, then the variables of interest (HbA1c, treatment category and their interactions) were entered.

RESULTS

There were 367 participants (mean age 80.1 ± 3.9 years, median [interquartile range] HbA1c 50 [45-56] mmol/mol or 6.7 [6.3-7.3]%) who were followed for a median (interquartile range) 6.7 (4.5-7.7) years, during which 40.9% of the participants died. At baseline, 60.4% were on metformin-based treatment, 35.3% on sulphonylurea-based treatment and 23.2% on treatment including insulin. Baseline HbA1c was significantly associated with mortality in a model that included interactions between HbA1c and the three treatment-based groups compared with non-pharmacological treatment. The metformin treatment group had higher mortality when HbA1c levels were <48 mmol/mol (<6.5%) and the sulphonylurea and insulin treatment groups had higher mortality when HbA1c levels were <52 mmol/mol (<7.0%), with hazard ratios of 2.63 (95% confidence interval [CI] 1.39-4.97), 2.49 (95% CI 1.14-5.44) and 2.22 (95% CI 1.12-4.43), respectively.

CONCLUSIONS

Tight glycaemic control may be hazardous in older people with type 2 diabetes when achieved with pharmacotherapy with metformin, and especially with insulin or sulphonylureas. These data confirm that overtreatment is likely to be an important clinical problem in this vulnerable population.

Hypoglycaemia in hospitalized patients with or without heart failure

Hospitalized patients with heart failure (HF) undergoing bedside glucose monitoring with subcutaneous insulin orders were retrospectively identified over 2 years. Hypoglycaemia was defined as any glucose value <3.9 mmol/L (70 mg/dL) within 24 hours of admission (Hypo_1day ) or throughout the hospitalization (Hypo_T ) or any glucose value <2.2 mmol/L (40 mg/dL) throughout the hospitalization (Hypo_Severe ). A total of 13 424 patients were included, of whom 2484 had HF. Patients with HF were more likely to have Hypo_1day (9.1% vs 7.0%, P = .0003), Hypo_T (28% vs 18.5%, P < .0001), or Hypo _Severe (3.4% vs 2.1%, P = .0001). After controlling for other variables, the odds of Hypo_1day were similar between the HF and non-HF groups (odds ratio [OR] 1.14, 95% CI 0.94-1.39, P = .18, fully adjusted model), slightly lower for Hypo_T (OR 0.85, 95% CI 0.73-0.99, P = .03, fully adjusted model), and similar for Hypo_Severe (OR 1.25, 95% CI 0.91-1.70, P = .17). Hypo_1day , Hypo_T and Hypo_Severe were all associated with increased mortality; there was no evidence of an interaction by HF status. Hypoglycaemia occurred at a similar or lower frequency in hospitalized patients with HF compared to those without HF. Hypoglycaemia was associated with increased hospital mortality, regardless of HF status.

Antihyperglycemic agents and cardiovascular outcomes: recent insights

PURPOSE OF REVIEW

To summarize cardiovascular outcome trials (CVOTs) with antihyperglycemic agents conducted since 2008 US Food and Drug Administration guidance.

RECENT FINDINGS

A series of large CVOTs since 2008 have included patients with type 2 diabetes (T2D), who are otherwise treated according to standard of care. After the initial trials with incretin agents demonstrated cardiovascular safety, two recent CVOTs with currently available antihyperglycemic agents - EMPA-REG OUTCOME with empagliflozin and LEADER with liraglutide - show a significant reduction of the primary composite outcome, including a significant difference in the cardiovascular death end-point in both trials [EMPA-REG OUTCOME: hazard ratio = 0.62, confidence interval (CI) = 0.49-0.77, P < 0.001 and LEADER: hazard ratio = 0.78, CI = 0.66-0.93, P = 0.007]. Number needed to treat to prevent one cardiovascular death of 46 and 77 for empagliflozin and liraglutide, respectively, over 3 years is comparable with other currently employed evidence-based cardioprotective strategies. In addition, EMPA-REG OUTCOME trial had a robust reduction in hospitalization for heart failure (hazard ratio = 0.65, CI = 0.50-0.85, P = 0.002).

SUMMARY

New-generation CVOTs are shifting the focus in the treatment of T2D to the prevention of cardiovascular morbidity and mortality.

Levels of serum uric acid at admission for hypoglycaemia predict 1-year mortality

AIMS

Hypoglycaemia represents a critical burden with clinical and social consequences in the management of diabetes. Serum uric acid (SUA) has been associated with cardiovascular diseases (CVD), but no conclusive findings are available nowadays in patients suffering from hypoglycaemia. We investigated whether SUA levels at the time of hypoglycaemia could predict all-cause mortality after 1-year follow-up.

METHODS

In total, 219 patients admitted to the Emergency Department (ED) of Ospedale Policlinico S. Martino of Genoa (Italy) have been enrolled between January 2011 and December 2014. The primary endpoint of the study consisted in determining whether SUA levels at the time of ED admission could predict the occurrence of death after 1 year.

RESULTS

The majority of patients were diabetic, especially type 2. CVD and chronic kidney disease were prevalent comorbidities. By a cut-off value obtained by the receiver operating characteristic curve analysis, a Kaplan-Meier analysis demonstrated that patients with SUA levels > 5.43 mg/dL were more prone to death after 1 year compared to those with lower SUA levels. The risk of death increased with high SUA levels both in the univariate and the multivariate models including estimated glomerular filtration rate, C-reactive protein, type of diabetes, and age-adjusted Charlson comorbidity index.

CONCLUSIONS

SUA could be useful as a predictor of 1-year mortality in hypoglycaemic patients, irrespective of severe comorbidities notably increasing the risk of death in these frail patients.

Increased Risk of Severe Hypoglycemic Events Before and After Cardiovascular Outcomes in TECOS Suggests an At-Risk Type 2 Diabetes Frail Patient Phenotype

OBJECTIVE

Severe hypoglycemic events (SHEs) in type 2 diabetes are associated with subsequent cardiovascular (CV) event risk. We examined whether CV events were associated with subsequent SHE risk.

RESEARCH DESIGN AND METHODS

Time-dependent associations between SHEs and a composite CV end point (fatal/nonfatal myocardial infarction or stroke, hospitalization for unstable angina, hospitalization for heart failure [hHF]) were examined post hoc in 14,671 TECOS (Trial Evaluating Cardiovascular Outcomes With Sitagliptin) participants with type 2 diabetes and CV disease followed for a median of 3.0 years.

RESULTS

SHEs were uncommon and unassociated with sitagliptin therapy (N = 160 [2.2%], 0.78/100 patient-years vs. N = 143 [1.9%], 0.70/100 patient-years for placebo; hazard ratio [HR] 1.12 [95% CI 0.89, 1.40], P = 0.33). Patients with (versus without) SHEs were older with longer diabetes duration, lower body weight, and lower estimated glomerular filtration rate; were more frequently women, nonwhite, and insulin treated; and more often had microalbuminuria or macroalbuminuria. Analyses adjusted for clinical factors showed SHEs were associated with increased risk of the primary composite CV end point (1.55 [1.06, 2.28], P = 0.025), all-cause death (1.83 [1.22, 2.75], P = 0.004), and CV death (1.72 [1.02, 2.87], P = 0.040). Conversely, nonfatal myocardial infarction (3.02 [1.83, 4.96], P < 0.001), nonfatal stroke (2.77 [1.36, 5.63], P = 0.005), and hHF (3.68 [2.13, 6.36], P < 0.001) were associated with increased risk of SHEs. Fully adjusted models showed no association between SHEs and subsequent CV or hHF events, but the association between CV events and subsequent SHEs remained robust.

CONCLUSIONS

These findings, showing greater risk of SHEs after CV events and greater risk of CV events after SHEs, suggest a common at-risk type 2 diabetes frail patient phenotype.

Cardiovascular Safety of Antidiabetic Drugs in the Hospital Setting

PURPOSE OF REVIEW

Patients with diabetes and/or stress hyperglycemia requires good glycemic control in the hospital setting, often requiring the use of glucose-lowering therapy. Standard-of-care dictates that non-insulin therapy be discontinued, with insulin therapy initiated using a basal-bolus approach. However, insulin is associated with a high risk for hypoglycemia and medical errors. Alternatives to insulin are needed in the inpatient setting, but the cardiovascular (CV) safety of non-insulin therapy is a concern.

RECENT FINDINGS

Most studies of antidiabetic drugs have been performed in the outpatient setting, and except for insulin therapy, trials in the inpatient setting have been insufficient to establish CV safety. Randomized controlled trials support the safety of insulin with more moderate glycemic control in the hospital, when hypoglycemia is minimized. Two recent multicenter randomized controlled clinical trials support the safety of sitagliptin, a dipeptidylpeptidase-4 inhibitor (DPP4i), in hospitalized patients, although the sample sizes were likely too small to detect CV events. Small trials suggest a possible CV benefit of glucagon-like peptide-1 receptor agonist therapy. A paucity of evidence and presence of side effects and cautions with insulin secretagogues, sodium glucose-co-transporter-2 inhibitors, and metformin preclude their routine use in the hospital setting. Available evidence is inadequate to evaluate the CV safety of most antidiabetic drug classes in the hospital setting. However, preliminary data from randomized clinical trials suggest the potential safety of the DPP4i sitagliptin.

Hypoglycaemia manifestations and recurrent events: Lessons from the SAVOR-TIMI 53 outcome study

Hypoglycaemia is a well-known risk associated with the use of sulphonylureas and insulin, often limiting achievement of glycaemic goals. Recognizing the precipitants and recurrence patterns of hypoglycaemic events, particularly major events, is therefore clinically important. The SAVOR-TIMI-53 trial was a cardiovascular outcome study of 16 492 patients allocated to saxagliptin vs placebo added to conventional care for a median of 2.1 years. Hypoglycaemic events were a prespecified outcome in the study and were defined as a symptomatic episode that recovered with carbohydrates or any recorded blood glucose <3.0 mmol/l (<54 mg/dL). A major event was defined as one that required third-party assistance. Analysis of the features of the first hypoglycaemic event for each patient showed that a precipitant for the event was recognized by fewer than half of the patients, with the precipitant most often being a missed meal. In 40% of patients reporting major hypoglycaemic events, no precipitating factor was recognized, and in >60%, no previous hypoglycaemic event was reported during the timespan of the study, underscoring the lack of predictability of such an event.

[Sudden cardiac death in diabetes mellitus]

Sudden cardiac death (SCD) represents one of the most frequent causes of death in patients with diabetes. In contrast to patients without diabetes it has not been significantly reduced despite improvements in the treatment of acute myocardial infarction and long-term treatment of cardiovascular diseases as well as diabetes mellitus. Several mechanisms can be responsible for the high incidence of SCD in diabetics: 1. arrhythmogenic effects mediated via cardiac autonomic neuropathy, repolarization disturbances or sympathetic tone activation (hypoglycemia), 2. myocardial ischemia due to atherosclerosis, endothelial dysfunction, platelet aggregation or thrombophilic effects, 3. myocardial disease due to inflammation, fibrosis, associated hypertension or uremia and 4. potassium imbalance due to diabetic nephropathy or hypoglycemia. This review introduces concepts of mechanisms that are responsible for SCD in patients with diabetes. Treatment of patients with diabetes should primarily consider a systematic assessment of any deterioration of this chronic disease and of complications at an early stage. Cardiovascular drug treatment corresponds to that of non-diabetics. In antidiabetic treatment drugs with a low risk of hypoglycemia should be preferred. Treatment with implantable cardioverter defibrillators (ICD) also combined with cardiac resynchronization therapy () demonstrated a high life-saving potential particularly in patients with diabetes.

Dipeptidyl peptidase-4 inhibitors and the risk of heart failure: a systematic review and meta-analysis

BACKGROUND

Given recent discrepant results from randomized controlled trials (RCTs), we examined the totality of RCT evidence assessing the association between dipeptidyl peptidase-4 (DPP-4) inhibitors and heart failure.

METHODS

MEDLINE, Embase and ClinicalTrials.gov were searched without language restrictions to August 2016 for RCTs comparing DPP-4 inhibitors to placebo or no therapy for a period of 24 weeks or more. We included all heart failure outcomes when listed either as a serious adverse event or adverse event. Pooled analyses used random-effects.

RESULTS

We identified 100 RCTs (n = 79 867) - 3 large cardiovascular-safety RCTs (SAVOR-TIMI 53[saxagliptin]/n = 16 492, EXAMINE[alogliptin]/n = 5380, and TECOS[sitagliptin]/n = 14 735), and 97 smaller RCTs with a primary outcome that was usually change in glycated hemoglobin. Virtually all RCTs were high-quality, multicentre, placebo-controlled trials. A total of 96% (1192/1244) of heart failure events were prespecified, blindly adjudicated and required hospital admission. Pooled results suggested a 13% increase in heart failure (relative risk [RR] 1.13, 95% confidence interval [CI] 1.01-1.26, I2 = 0%; 32 RCTs, n = 54 640, 1244 events). When including only the 3 large RCTs, the increase was similar, but not significant (RR 1.14, 95% CI 0.97-1.32; 3 RCTs, n = 36 543, 1169 adjudicated events; number needed to harm 246) owing to heterogeneity (I2 = 42%), which lead to wider CIs, because SAVOR-TIMI 53 showed increased heart failure (RR 1.26, 95% CI 1.06-1.49) and TECOS showed no effect (RR 1.00, 95% CI 0.83-1.19).

INTERPRETATION

Despite pooled data from 79 867 patients, whether DPP-4 inhibitors increase heart failure overall or exhibit within-class differences remains unresolved. Our results highlight the importance of ongoing trials that are comparing DPP-4 inhibitors to placebo, although no large cardiovascular-safety RCTs are comparing different DPP-4 inhibitors to each other; consequently, these will address the overall but not class-difference question.

Predisposing Factors for Any and Major Hypoglycemia With Saxagliptin Versus Placebo and Overall: Analysis From the SAVOR-TIMI 53 Trial

OBJECTIVE

To analyze the impact of adding saxagliptin versus placebo on the risk for hypoglycemia and to identify predictors of any and major hypoglycemia in patients with type 2 diabetes included in the Saxagliptin Assessment of Vascular Outcomes Recorded in Patients with Diabetes Mellitus-Thrombolysis in Myocardial Infarction 53 (SAVOR-TIMI 53) study.

RESEARCH DESIGN AND METHODS

Patients with type 2 diabetes (n = 16,492) were randomized to saxagliptin or placebo and followed for a median of 2.1 years. Associations between any hypoglycemia (symptomatic or glucose measurement <54 mg/dL) or major hypoglycemia (requiring extended assistance) and patient characteristics overall and by treatment allocation were studied.

RESULTS

At least one hypoglycemic event was reported in 16.6% of patients, and 1.9% reported at least one major event. Patients allocated to saxagliptin versus placebo experienced higher rates of any (hazard ratio [HR] 1.16 [95% CI 1.08, 1.25]; P < 0.001) or major (HR 1.26 [1.01, 1.58]; P = 0.038) hypoglycemia. Hypoglycemia rates (any or major) were increased with saxagliptin in patients taking sulfonylureas (SURs) but not in those taking insulin. Rates were increased with saxagliptin in those with baseline HbA1c ≤7.0% and not in those with baseline HbA1c >7.0%. Multivariate analysis of the overall population revealed that independent predictors of any hypoglycemia were as follows: allocation to saxagliptin, long duration of diabetes, increased updated HbA1c, macroalbuminuria, moderate renal failure, SUR use, and insulin use. Predictors of major hypoglycemia were allocation to saxagliptin, advanced age, black race, reduced BMI, long duration of diabetes, declining renal function, microalbuminuria, and use of short-acting insulin. Among SURs, glibenclamide was associated with increased risk of major but not any hypoglycemia.

CONCLUSIONS

The identification of patients at risk for hypoglycemia can guide physicians to better tailor antidiabetic therapy.