Diabetes for Cardiologists: Practical Issues in Diagnosis and Management

2022 Canadian Cardiovascular Society Guideline for Use of GLP-1 Receptor Agonists and SGLT2 Inhibitors for Cardiorenal Risk Reduction in Adults

This guideline synthesizes clinical trial data supporting the role of glucagon-like peptide-1 receptor agonists and sodium-glucose co-transporter 2 inhibitors (SGLT2i) for treatment of heart failure (HF), chronic kidney disease, and for optimizing prevention of cardiorenal morbidity and mortality in patients with type 2 diabetes. It is on the basis of a companion systematic review and meta-analysis guided by a focused set of population, intervention, control, and outcomes (PICO) questions that address priority cardiorenal end points. The Grading of Recommendations, Assessment, Development, and Evaluation (GRADE) system and a modified Delphi process were used. We encourage comprehensive assessment of cardiovascular (CV) patients with routine measurement of estimated glomerular filtration rate, urinary albumin-creatinine ratio, glycosylated hemoglobin (A1c), and documentation of left ventricular ejection fraction (LVEF) when evaluating symptoms of HF. For patients with HF, we recommend integration of SGLT2i with other guideline-directed pharmacotherapy for the reduction of hospitalization for HF when LVEF is > 40% and for the reduction of all-cause and CV mortality, hospitalization for HF, and renal protection when LVEF is ≤ 40%. In patients with albuminuric chronic kidney disease, we recommend integration of SGLT2i with other guideline-directed pharmacotherapy to reduce all-cause and CV mortality, nonfatal myocardial infarction, and hospitalization for HF. We provide recommendations and algorithms for the selection of glucagon-like peptide-1 receptor agonists and SGLT2i for patients with type 2 diabetes and either established atherosclerotic CV disease or risk factors for atherosclerotic CV disease to reduce all-cause and CV mortality, nonfatal stroke, and for the prevention of hospitalization for HF and decline in renal function. We offer practical advice for safe use of these diabetes-associated agents with profound cardiorenal benefits.

Liraglutide Effect on Weight, Glycated Hemoglobin, and Blood Pressure: A Single-Center Experience in the Eastern Province of Saudi Arabia

Background

Liraglutide has pleiotropic effects beneficial to patients with cardiovascular and renal risks. These effects have been linked to weight and blood pressure reduction in type 2 diabetes (T2D) patients. However, whether this reduction is similar in all patients regardless of their ethnicity, baseline demographic, or clinical characteristics is unknown. This study aimed to identify the efficacy of liraglutide on weight, glycated hemoglobin (HbA1c), and blood pressure in Saudi patients with T2D who attended King Fahad Hospital of the University and received liraglutide as add-on therapy to other antihyperglycemic agents. The study also aimed to describe the pattern of change in these clinical parameters before and after the treatment and assess whether sex differences affect liraglutide's efficacy.

Methods

We conducted a retrospective longitudinal study reviewing medical records of 220 Saudi patients with T2D treated at King Fahad Hospital of the University (KFHU), in Al-Khobar city in the Eastern Province of Saudi Arabia, from December 2016 to November 2021. Patient cases were included if the patient was Saudi, aged 18 or older, and received liraglutide in a dose of at least 0.6 mg/day for at least three months in combination with other antihyperglycemic agents/diabetes medications. We recorded the effect on patient HbA1c, systolic blood pressure (SBP) and diastolic blood pressure (DBP), body mass index (BMI), and body weight at baseline, during, and after treatment. We used the paired t-test and repeated measure analysis of variance to compare the mean study parameters before and after treatment. Furthermore, an independent t-test was used to compare the mean study parameters among men and women.

Results

Treatment with liraglutide from 0.6 mg/day to 3 mg/day for three to 18 months had optimal results across the outcomes measured in our cohort study. There was a significant reduction in weight from baseline to 18 months from a mean weight of 97.9±20 kg to 96.51±18.45 kg with (p<0.001). Mean HbA1c at baseline was 9.34%±1.95%, dropped to 7.67%±1.11% (p<0.001) at 18 months. Moreover, mean SBP also significantly decreased from 126.61±10.4 mmHg to 122.48±7.29 mmHg by the last follow-up (p<0.001). Mean DBP was 76.54±8.37 mmHg at baseline and decreased to 74.29±6.22 mmHg at last follow-up (p<0.001). Men treated with liraglutide had greater reductions in weight than women throughout the study (p<0.05), and while men had greater reductions in SBP and DBP than women early in treatment (p<0.05), by the end of treatment, there were no significant differences in blood pressure between men and women. Likewise, we saw no significant difference between HbA1c reductions in men and women treated with liraglutide.

Conclusion

Liraglutide effectively reduces HbA1c, weight, BMI, SBP, and DBP in T2D patients. These study results reflect real-world liraglutide clinical practices from KFHU and can be beneficial for physicians when considering using liraglutide as add-on therapy in this population.

Jiangtang Tongmai Prescription Reduced Diabetic Lung Injury Through SnoN and TGF-β1/Smads Signaling Pathway

By establishing a rat diabetes model in rats with intervening treatment by Jiangtang Tongmai Prescription (JTTMP), this study explored the restorative pairing effect of JTTMP on diabetic lung injury. The model of type II diabetes model was used to establish the rat diabetes model, using a high-fat diet and streptozotocin (STZ) induction. Different doses of JTTMP and metformin were administered as a therapeutic to intervene, and blood was collected to assess the blood glucose level of each group of rats. HE (Hematoxylin and eosin (H&E) staining was performed to detect the morphological changes in rat lung tissue and enzyme-linked immunoassay ELISA was used to detect and quantify the expression of interleukin (IL)-6, TNF tumor necrosis factor-ɑa, and IL-1β in serum and the lung tissue of each group of rats. The level expression of TGF-β1 [transforming growth factor (TGF)-β1), SnoN (transcriptional co-repressor Ski-N terminal (SnoN)], Smad2, Smad3, Smad7, and other signaling pathway proteins were assessed by Western blot. In comparison with the normal control (NC) group, rats in the diabetes model (DM) group lost weight and showed significantly increased blood sugar levels. The levels of TGF-β1 and Smad2/3 were increased in the DM group but Smad7 decreased. After 8 weeks of JTTMP intervention, the level of TGF-β1 and Smad2/3 decreased but Smad7 increased, blood sugar decreased significantly and the expression of inflammatory factors in lung tissue decreased. Therefore, JTTMP may activate SnoN and the downstream TGF-β1/Smads signaling pathway to repair diabetic lung injury, which suggests its application has potential for future clinical treatment of diabetes with lung injury.

The Goto Kakizaki rat: Impact of age upon changes in cardiac and renal structure, function

BACKGROUND

Patients with diabetes are at a high risk for developing cardiac dysfunction in the absence of coronary artery disease or hypertension, a condition known as diabetic cardiomyopathy. Contributing to heart failure is the presence of diabetic kidney disease. The Goto-Kakizaki (GK) rat is a non-obese, non-hypertensive model of type 2 diabetes that, like humans, shares a susceptibility locus on chromosome 10. Herein, we perform a detailed analysis of cardio-renal remodeling and response to renin angiotensin system blockade in GK rats to ascertain the validity of this model for further insights into disease pathogenesis.

METHODS

Study 1: Male GK rats along with age matched Wistar control animals underwent longitudinal assessment of cardiac and renal function for 32 weeks (total age 48 weeks). Animals underwent regular echocardiography every 4 weeks and at sacrifice, early (~24 weeks) and late (~48 weeks) timepoints, along with pressure volume loop analysis. Histological and molecular characteristics were determined using standard techniques. Study 2: the effect of renin angiotensin system (RAS) blockade upon cardiac and renal function was assessed in GK rats. Finally, proteomic studies were conducted in vivo and in vitro to identify novel pathways involved in remodeling responses.

RESULTS

GK rats developed hyperglycaemia by 12 weeks of age (p<0.01 c/w Wistar controls). Echocardiographic assessment of cardiac function demonstrated preserved systolic function by 48 weeks of age. Invasive studies demonstrated left ventricular hypertrophy, pulmonary congestion and impaired diastolic function. Renal function was preserved with evidence of hyperfiltration. Cardiac histological analysis demonstrated myocyte hypertrophy (p<0.05) with evidence of significant interstitial fibrosis (p<0.05). RT qPCR demonstrated activation of the fetal gene program, consistent with cellular hypertrophy. RAS blockade resulted in a reduction blood pressure(P<0.05) cardiac interstitial fibrosis (p<0.05) and activation of fetal gene program. No significant change on either systolic or diastolic function was observed, along with minimal impact upon renal structure or function. Proteomic studies demonstrated significant changes in proteins involved in oxidative phosp4horylation, mitochondrial dysfunction, beta-oxidation, and PI3K/Akt signalling (all p<0.05). Further, similar changes were observed in both LV samples from GK rats and H9C2 cells incubated in high glucose media.

CONCLUSION

By 48 weeks of age, the diabetic GK rat demonstrates evidence of preserved systolic function and impaired relaxation, along with cardiac hypertrophy, in the presence of hyperfiltration and elevated protein excretion. These findings suggest the GK rat demonstrates some, but not all features of diabetes induced "cardiorenal" syndrome. This has implications for the use of this model to assess preclinical strategies to treat cardiorenal disease.

Expression of transient receptor potential vanilloid genes and proteins in diabetic rat heart

Cardiac complications are leading causes of death in diabetic patients. Imbalance of Ca²⁺ homeostasis is a hallmark of cardiac dysfunction in diabetes, while TRPV channels are non-selective for cations and are permeable to Ca²⁺. Our aim was to evaluate the expression levels of TRPV1, TRPV2, TRPV3, TRPV4, TRPV5, and TRPV6 genes and proteins in cardiac tissue at 3 days and 4, 8, and 12 weeks after induction of diabetes. Sprague-Dawley rats were assigned to control and DM groups. DM was induced by intraperitoneal injection of streptozotocin (60 mg/kg). The expression levels of TRPV genes were analyzed by the quantitative reverse transcription polymerase chain reaction, and TRPV proteins were determined by western blotting. Compared to controls, the expression levels of TRPV2, TRPV3, and TRPV6 in diabetic myocardium did not change, while TRPV1 decreased at 4, 8, and 12 weeks, TRPV4 was upregulated at 3 days and 4, 8, and 12 weeks, TRPV5 mRNA increased at 8 and 12 weeks, and TRPV5 protein increased at 4, 8, and 12 weeks. Our findings showed that TRPV1, TRPV4, and TRPV5 are associated with the diabetic heart.

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.

Chicoric acid attenuates hyperglycemia-induced endothelial dysfunction through AMPK-dependent inhibition of oxidative/nitrative stresses

BACKGROUND

Endothelial dysfunction is a driving force during the development and progression of cardiovascular complications in diabetes. Targeting endothelial injury may be an attractive avenue for the management of diabetic vascular disorders. Chicoric acid is reported to confer antioxidant and anti-inflammatory properties in various diseases including diabetes. However, the role and mechanism of chicoric acid in hyperglycemia-induced endothelial damage are not well understood.

METHODS

In the present study, human umbilical vein endothelial cells (HUVECs) were incubated with high glucose/high fat (HG + HF) to induce endothelial cell injury.

RESULTS

We found that exposure of HUVECs to HG + HF medium promoted the release of cytochrome c (cytc) from mitochondrion into the cytoplasm, stimulated the cleavage of caspase-3 and poly ADP-ribose-polymerase (PARP), then inducing cell apoptosis, the effects that were prevented by administration of chicoric acid. Besides, we found that chicoric acid diminished HG + HF-induced phosphorylation and degradation of IκBα, and subsequent p65 NFκB nuclear translocation, thereby contributing to its anti-inflammatory effects in HUVECs. We also confirmed that chicoric acid mitigated oxidative/nitrative stresses under HG + HF conditions. Studies aimed at exploring the underlying mechanisms found that chicoric acid activated the AMP-activated protein kinase (AMPK) signaling pathway to attenuate HG + HF-triggered injury in HUVECs as AMPK inhibitor Compound C or silencing of AMPKα1 abolished the beneficial effects of chicoric acid in HUVECs.

CONCLUSION

Collectively, chicoric acid is likely protected against diabetes-induced endothelial dysfunction by activation of the AMPK signaling pathway. Chicoric acid could be a novel candidate for the treatment of the diabetes-associated vascular endothelial injury.

Association between vitamin D and prediabetes: A PRISMA-compliant meta-analysis

BACKGROUND

Previous studies showed conflicting results for associations between vitamin D and prediabetes. The study aimed to make a systematic review and meta-analysis for the association between vitamin D and prediabetes.

METHODS

We searched for articles identifying associations between vitamin D and prediabetes published in English until July 2019 in following databases (PubMed, Web of Science, EMBASE, Medline, Google Scholar, and Cochrane databases). Finally, we conducted these analyses (heterogeneities examination, meta-regression analyses, sensitivity analysis, and publication bias examination) using STATA 12.0 software (Stata Corporation, College Station, TX, USA). Q test and I were applied to examine heterogeneities between studies.

RESULTS

Twelve studies were finally included in the present study. The study included 4 studies to explore the association between serum levels of 25-hydroxy (OH) vitamin D and risks of prediabetes (including 3094 participants). Additionally, the present study included 8 studies (including 865 individuals with prediabetes treated with vitamin D supplementation and 715 patients treated with placebo) to assess differences in therapeutic effects between individuals with prediabetes treated with vitamin D supplementation and those treated with placebo. The present study showed no significant associations between low serum levels of 25(OH) vitamin D and high risk of prediabetes. Additionally, the study showed no significant differences in changes of hemoglobin A1c (HbA1c), fasting plasma glucose (FPG), and homeostatic model assessment of insulin resistance (HOMA-IR) between individuals with prediabetes treated with vitamin D and those patients given placebo, whereas meta-analysis showed significantly greater changes in 2-hour oral glucose tolerance test (2HPG) in individuals with prediabetes treated with vitamin D, compared with individuals with prediabetes treated with placebo.

CONCLUSION

The study supported that low serum levels of 25(OH) vitamin D increased the risk of prediabetes. In addition, vitamin D supplementation improves impaired glucose tolerance in prediabetes. However, more large-scale clinical trials are essential to explore the association between vitamin D and prediabetes.

Direct Effects of Empagliflozin on Extracellular Matrix Remodelling in Human Cardiac Myofibroblasts: Novel Translational Clues to Explain EMPA-REG OUTCOME Results

BACKGROUND

Empagliflozin, an SGLT2 inhibitor, has shown remarkable reductions in cardiovascular mortality and heart failure admissions (EMPA-REG OUTCOME). However, the mechanism underlying the heart failure protective effects of empagliflozin remains largely unknown. Cardiac fibroblasts play an integral role in the progression of structural cardiac remodelling and heart failure, in part, by regulating extracellular matrix (ECM) homeostasis. The objective of this study was to determine if empagliflozin has a direct effect on human cardiac myofibroblast-mediated ECM remodelling.

METHODS

Cardiac fibroblasts were isolated via explant culture from human atrial tissue obtained at open heart surgery. Collagen gel contraction assay was used to assess myofibroblast activity. Cell morphology and cell-mediated ECM remodelling was examined with the use of confocal microscopy. Gene expression of profibrotic markers was assessed with the use of reverse-transcription quantitative polymerase chain reaction.

RESULTS

Empagliflozin significantly attenuated transforming growth factor β1-induced fibroblast activation via collagen gel contraction after 72-hour exposure, with escalating concentrations (0.5 μmol/L, 1 μmol/L, and 5 μmol/L) resulting in greater attenuation. Morphologic assessment showed that myofibroblasts exposed to empagliflozin were smaller in size with shorter and fewer number of extensions, indicative of a more quiescent phenotype. Moreover, empagliflozin significantly attenuated cell-mediated ECM remodelling as measured by collagen fibre alignment index. Gene expression profiling revealed significant suppression of critical profibrotic markers by empagliflozin, including COL1A1, ACTA2, CTGF, FN1, and MMP-2.

CONCLUSIONS

We provide novel data showing a direct effect of empagliflozin on human cardiac myofibroblast phenotype and function by attenuation of myofibroblast activity and cell-mediated collagen remodelling. These data provide critical insights into the profound effects of empagliflozin as noted in the EMPA-REG OUTCOME study.

Metformin Modulates High Glucose-Incubated Human Umbilical Vein Endothelial Cells Proliferation and Apoptosis Through AMPK/CREB/BDNF Pathway

Cardiovascular disease (CVD) is a leading cause of mortality and morbidity among patients with diabetes. Endothelial dysfunction is an early physiological event in CVD. Metformin, a common oral antihyperglycemic agent, has been demonstrated to directly affect endothelial cell function. Brain-derived neurotrophic factor (BDNF), originally discovered in the brain as a neurotrophin, has also been reported to play a protective role in the cardiovascular system. In our study, we demonstrated that high glucose (HG) reduced cell proliferation and induced cell apoptosis via changes in BDNF expression and that metformin reversed the effects of HG injury by upregulating BDNF expression. Furthermore, we found that cyclic AMP response element binding (CREB) phosphorylation was reduced in HG-treated human umbilical vein endothelial cells (HUVECs), and this effect was reversed by the metformin treatment. However, the metformin effect on BDNF levels in HG-incubated HUVECs was blocked by a CREB inhibitor, which indicated that BDNF expression is regulated by metformin through CREB activation. In addition, we found that adenosine monophosphate-activated protein kinase (AMPK) activation is involved in CREB/BDNF regulation in HG-incubated HUVECs treated with metformin and that an AMPK inhibitor impaired the protective effects of metformin on HG-treated HUVECs. In conclusion, this study demonstrated that metformin affects cell proliferation and apoptosis via the AMPK/CREB/BDNF pathway in HG-incubated HUVECs.

Curcumin, Cardiometabolic Health and Dementia

Current research indicates curcumin [diferuloylmethane; a polyphenolic compound isolated from the rhizomes of the dietary spice turmeric (Curcuma longa)] exerts a beneficial effect on health which may be partly attributable to its anti-oxidative and anti-inflammatory properties. The aim of this review is to examine potential mechanisms of the actions of curcumin in both animal and human studies. Curcumin modulates relevant molecular target pathways to improve glucose and lipid metabolism, suppress inflammation, stimulate antioxidant enzymes, facilitate insulin signalling and reduce gut permeability. Curcumin also inhibits Aβ and tau accumulation in animal models and enhances mitochondria and synaptic function. In conclusion, in high-dose animal studies and in vitro, curcumin exerts a potential beneficial effect on cardiometabolic disease. However, human studies are relatively unconvincing. More intervention studies should be conducted with the new curcumin formulation with improved oral bioavailability.

Activating transcription factor 3 in cardiovascular diseases: a potential therapeutic target

Cardiovascular diseases (CVDs) are the primary causes of death worldwide. Among the numerous signaling molecules involved in CVDs, transcriptional factors directly influence gene expression and play a critical role in regulating cell function and the development of diseases. Activating transcription factor (ATF) 3 is an adaptive-response gene in the ATF/cAMP responsive element-binding (CREB) protein family of transcription factors that acts as either a repressor or an activator of transcription via the formation of homodimers or heterodimers with other ATF/CREB members. A appropriate ATF3 expression is important for the normal physiology of cells, and dysfunction of ATF3 is associated with various pathophysiological responses such as inflammation, apoptosis, oxidative stress and endoplasmic reticulum stress, and diseases, including CVDs. This review focuses on the role of ATF3 in cardiac hypertrophy, heart failure, atherosclerosis, ischemic heart diseases, hypertension and diabetes mellitus to provide a novel therapeutic target for CVDs.

Vitamin D Supplementation, Glycemic Control, and Insulin Resistance in Prediabetics: A Meta-Analysis

Diabetes prevention is a public health priority. Vitamin D supplementation may help prevent the development of diabetes in persons at increased risk. We performed a meta-analysis of controlled clinical trials that assessed glycemic outcome measures among adults at risk for type 2 diabetes, including prediabetes, overweight, or obesity. We searched PUBMED/ MEDLINE, CINAHL, and Google Scholar databases for trials published prior to April 2017. Placebo-controlled clinical trials with random allocation to vitamin D with or without calcium supplementation were selected. Data collection included country, study design, inclusion criteria, sample size, form, and dose of vitamin D, supplementation interval, control group, duration, participant characteristics, comorbidities, baseline and follow-up serum 25-hydroxyvitamin D [25(OH)D] concentration, and available outcome measures [glycosylated hemoglobin (HbA1c), fasting plasma glucose, plasma glucose after 2-hour oral glucose tolerance test, and homeostatic model assessment of insulin resistance (HOMA-IR)]. Data synthesis was conducted using random-effect models (PROSPERO registration no. CRD42017055326). Twenty-eight trials, representing 3848 participants, met the eligibility criteria. Compared with the control group, vitamin D supplementation significantly reduced HbA1c level by -0.48% (95% CI, -0.79 to -0.18), fasting plasma glucose level by -0.46 mmol/L (95% CI, -0.74 to -0.19), and HOMA-IR level by -0.39 (95% CI, -0.68 to -0.11). Subgroup analysis revealed that the effects of vitamin D supplementation on different glycemic measures were influenced by age, calcium coadministration, vitamin D deficiency, serum 25(OH)D level after supplementation, and duration of supplementation. Vitamin D supplementation and improved vitamin D status improved glycemic measures and insulin sensitivity and may be useful as part of a preventive strategy for type 2 diabetes.

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.

Revascularization for patients with diabetes mellitus and stable ischemic heart disease: an update

PURPOSE OF REVIEW

To provide an update on the management of patients with diabetes mellitus and requiring coronary revascularization.

RECENT FINDINGS

Evidence continues to show that patients with diabetes mellitus and ischemic heart disease represent a very high-risk group of patients. Choice of stent appears important for minimizing target lesion and target vessel adverse events with everolimus eluting stents having the best performance, particularly in patients being treated with insulin. The higher risk of adverse angioplasty results in patients with diabetes appears most related to the disease state per se and not necessarily to anatomical complexities. Interestingly, physiologic documentation of nonischemia producing lesions with use of fractional flow reserve appears less reassuring in this setting of aggressive and rapid atherosclerosis progression, particularly if myocardial infarction has occurred previously, than in patients without diabetes. Coronary artery bypass surgery in patients with appropriate anatomy and diabetes continues to emerge in many analyzes as the optimal, long-term therapy.

IMPLICATIONS

The treatment of diabetes per se, advances in stent technology and optimization of coronary artery bypass techniques are all occurring in parallel making it very critical for the design of modern era trials that keep pace with these advances. Currently, in patients with appropriate anatomy who are willing candidates, bypass surgery remains the optimal, long-term therapeutic option.

MiR-31 regulates the function of diabetic endothelial progenitor cells by targeting Satb2

Endothelial malfunctions in patients with diabetes are known to result in vascular diseases, and endothelial progenitor cells (EPCs) are indispensable for the functional preservation of the vascular endothelium. MicroRNA-31 (miR-31) has been found to be able to modulate the differentiation of stem cells. However, it is still unclear how miR-31 functions in diabetic EPCs. The aim of this study was to investigate how miR-31 regulates diabetic EPC function. In the current study, miR-31 expression was compared between normal and diabetic EPCs. Satb2 was recognized as a functionally related target of miR-31 in EPCs according to computational prediction. We also explored the role of miR-31 in terms of its anti-apoptotic effects. A remarkable elevation in miR-31 expression was found in diabetic EPCs, and this elevated expression resulted in suppressed cell proliferation under high glucose. It was also found that miR-31 targets Satb2, leading to the anti-apoptotic effect and maintenance of the functions of EPCs. Furthermore, knockdown of Satb2 exhibited an inhibitory effect on proliferation and migration of EPCs in both healthy and diabetic subjects, which showed the same trend as miR-31 overexpression. Conversely, overexpression of Satb2 showed the opposite effect. Moreover, overexpression of Satb2 attenuated the miR-31-induced migration and colony-forming ability reduction and apoptosis induction of EPCs in both healthy and diabetic subjects. In diabetic EPCs, elevated glucose level was found to up-regulate miR-31 expression, which in turn enhanced the malfunction and death of EPCs. In conclusion, our results indicate that up-regulation of miR-31 may underlie endothelial dysfunction in diabetes by targeting Satb2.

Preanesthetic evaluation of the patient with end-stage heart failure

Heart failure (HF) currently affects more than 5 million patients in the United States [1]. Advanced HF is associated with high mortality and poor quality of life. It is estimated that between 5% and 10% of all patients with HF have an advanced form of the disease [1]. Orthotopic heart transplantation (OHT) is an accepted therapy for stage D HF [3] (Fig. 1). Unfortunately, the number of patients with the disease exceeds the number of available organs. This makes appropriate patient selection vital in the field of heart transplantation. Anesthetic evaluation of the patient presenting for OHT or mechanical circulatory support (MCS) implantation is a vital component of the patient's perioperative course. Patients often have had extensive diagnostic testing and assessment prior to being listed for OHT or considered for MCS implantation. Because of the often urgent nature of these procedures, the cardiac anesthesiologist must conduct a focused review of the relevant information and perform a focused patient interview and physical exam.

Impact of continuation of metformin prior to elective coronary angiography on acute contrast nephropathy in patients with normal or mildly impaired renal functions

Objective:

Discontinuation of metformin treatment in patients scheduled for elective coronary angiography (CAG) is controversial because of post-procedural risks including acute contrast-induced nephropathy (CIN) and lactic acidosis (LA). This study aims to discuss the safety of continuing metformin treatment in patients undergoing elective CAG with normal or mildly impaired renal functions.

Methods:

Our study was designed as a single-centered, randomized, and observational study including 268 patients undergoing elective CAG with an estimated glomerular filtration rate of >60 mL/min/1.73 m². Of these patients, 134 continued metformin treatment during angiography, whereas 134 discontinued it 24 h before the procedure. CIN was defined as either a 25% relative increase in serum creatinine levels from the baseline or a 0.5 mg/dL increase in the absolute value that measured 48 h after CAG. Logistic regression analysis was performed to identify independent predictors of CIN and LA after CAG.

Results:

Both groups were comparable in terms of demographics and laboratory values. CIN at 48 h was 8% (11/134) in the metformin continued group and 6% (8/134) in the metformin discontinued group (p=0.265). Patients in neither of the groups developed metformin-induced LA. Based on multiple regression analysis, the ejection fraction [p=0.029, OR: 0.760; 95% CI (0.590–0.970)] and contrast volume [p=0.016, OR: 0.022 95% CI (0.010–0.490)] were independent predictors of CIN.

Conclusion:

Patients scheduled for elective CAG with normal or mildly impaired renal functions and preserved left ventricular ejection fraction (>40%) may safely continue metformin treatment.

Novel Biomarkers for Predicting Cardiovascular Disease in Patients With Diabetes

It is generally acknowledged that patients with diabetes comprise a high-risk population for the development of cardiovascular disease. However, it is perhaps less well recognized that there actually exists considerable heterogeneity in vascular risk within this patient population, with a sizable subset of individuals seemingly at low risk for major cardiovascular events despite the presence of diabetes. Because traditional clinical risk calculators have shown wide variability in their performance in the setting of diabetes, there exists a need for additional risk predictors in this patient population. In this context, there has been considerable interest in the potential utility of circulating biomarkers as clinical tools that might facilitate risk stratification and thereby guide therapeutic and preventative decision-making. Coupled with the current era of dedicated cardiovascular outcome trials in type 2 diabetes, this interest has spawned a growing literature of recent studies that evaluated potential biomarkers. To date, these studies have identified N-terminal pro-B-type natriuretic peptide, high-sensitivity cardiac troponins, and growth differentiation factor-15 as cardiovascular biomarkers of particular potential in patients with diabetes. Furthermore, recognizing the potential benefit of collective consideration of different biomarkers reflecting distinct pathophysiologic processes that might contribute to the development of cardiovascular disease, there is emerging emphasis on the evaluation of combinations of biomarkers for optimal risk prediction. Although not currently ready for clinical practice, this rapidly-growing topic of biomarker research might ultimately facilitate the goal of individualized risk stratification and thereby enable truly personalized management of diabetes.