Cardiovascular disease and type 2 diabetes mellitus: a multifaceted symbiosis

The Impact of Selenium Deficiency on Cardiovascular Function

Selenium (Se) is an essential trace element that is necessary for various metabolic processes, including protection against oxidative stress, and proper cardiovascular function. The role of Se in cardiovascular health is generally agreed upon to be essential yet not much has been defined in terms of specific functions. Se deficiency was first associated with Keshan’s Disease, an endemic disease characterized by cardiomyopathy and heart failure. Since then, Se deficiency has been associated with multiple cardiovascular diseases, including myocardial infarction, heart failure, coronary heart disease, and atherosclerosis. Se, through its incorporation into selenoproteins, is vital to maintain optimal cardiovascular health, as selenoproteins are involved in numerous crucial processes, including oxidative stress, redox regulation, thyroid hormone metabolism, and calcium flux, and inadequate Se may disrupt these processes. The present review aims to highlight the importance of Se in cardiovascular health, provide updated information on specific selenoproteins that are prominent for proper cardiovascular function, including how these proteins interact with microRNAs, and discuss the possibility of Se as a potential complemental therapy for prevention or treatment of cardiovascular disease.

Greater macrovascular and microvascular morbidity from type 2 diabetes in northern compared with southern China: A cross-sectional study

AIMS/INTRODUCTION

There are substantial differences in genes, diet, culture and environment between the northern and southern Chinese populations, which might influence treatment strategy and screening policy. We studied the differences in type 2 diabetes and diabetic complications between northern and southern China.

MATERIALS AND METHODS

We carried out a cross-sectional survey using data from the China Cardiometabolic Registries on blood pressure, blood lipids and blood glucose in 25,398 Chinese type 2 diabetes patients. Macrovascular, microvascular and other complications were collected by self-report or medical records, and then divided into the northern and southern groups by the boundary of the Yangtze River.

RESULTS

Northern patients were younger, and had heavier weight, greater body mass index and waist circumference, higher blood pressure, higher total cholesterol, higher low-density lipoprotein cholesterol, and higher hemoglobin A1C. The prevalence of cardiovascular, cerebrovascular and macrovascular complications were 1.76-fold, 1.24-fold and 1.47-fold more in northern than that in southern Chinese patients. In addition, the prevalence of diabetic nephropathy, retinopathy, neuropathy and microvascular complications in northern Chinese patients also increased. When stratified by age, the difference in both cardiovascular disease and ischemic stroke morbidity became significant, even in the 35-44 years age group.

CONCLUSIONS

More macrovascular and microvascular complications were found in northern compared with southern patients, and the largest difference also appeared in the younger age groups <55 years, which might be meaningful to a screening and treatment strategy according to geographic differences.

Cardiovascular Effects of Sodium Glucose Co-transporter-2 Inhibitors in Patients with Type 2 Diabetes Mellitus

Type 2 diabetes mellitus (T2DM), the leading type of diabetes, has a typical association with coronary heart disease. In India, patients with diabetes are at an increased risk of developing coronary disease as compared to people without diabetes and this suggests the requirement of intensive treatment of cardiovascular (CV) risk factors. Consequently, there is a need for an intervention that could target CV risk factors in multiple paths beyond hyperglycemic control alone. Although metformin is the mainstay of treatment in most of the patients with T2DM, a second line of treatment with anti-hyperglycemic agent is warranted in patients with T2DM in the management of CV risk factors beyond glycemic control. Sodium glucose co-transporter-2 (SGLT-2) inhibitors, the oral hypoglycemic drug, that act independent of insulin secretion are associated with a reduced risk of hypoglycemia which is associated with the increased risk of CV events. Moreover, it has been observed that the use of SGLT-2 inhibitors in patients with T2DM is associated with reductions in blood pressure and body weight beyond improved glycemic control. In this article, the clinical efficacy, safety, and tolerability of SGLT-2 inhibitors on glycemic, nonglycemic parameters, and CV outcome including data from the EMPA-REG OUTCOME study are discussed. The EMPA-REG OUTCOME study is the first CV outcome study that demonstrated the association of a glucose lowering agent with the reduced CV mortality and all-cause mortality, and reduced hospitalization for heart failure in patients with T2DM at high risk of CV events. Although the mode of action associated with the CV benefits remains unknown, data from ongoing trials including DECLARE-TIMI (Dapagliflozin Effect on CV Events) and CANVAS (Canagliflozin CV Assessment Study) trials potentially can validate the class-effect for SGLT-2 inhibitors regarding the CV outcomes.

Efficacy and safety of canagliflozin in patients with type 2 diabetes based on history of cardiovascular disease or cardiovascular risk factors: a post hoc analysis of pooled data

Background

Treatment of patients with type 2 diabetes mellitus (T2DM) and a history of cardiovascular (CV) disease or CV risk factors may present clinical challenges due to the presence of comorbid conditions and the use of concomitant medications. The sodium glucose co-transporter 2 inhibitor, canagliflozin, has been shown to improve glycaemic control and reduce body weight and blood pressure (BP) with a favourable tolerability profile in a broad range of patients with T2DM. This post hoc analysis assessed the efficacy and safety of canagliflozin in patients with T2DM based on CV disease history or CV risk factors.

Methods

Analyses were based on pooled data from four 26-week, placebo-controlled, Phase 3 studies that evaluated canagliflozin 100 and 300 mg in patients with T2DM (N = 2313; mean HbA1c, 8.0%; body weight, 89 kg; systolic BP, 128 mmHg). Changes from baseline to week 26 in HbA1c, body weight, and systolic BP were assessed based on history of CV disease, history of hypertension, baseline statin use, and number of CV risk factors. Safety was assessed based on adverse event (AE) reports.

Results

At week 26, both canagliflozin doses lowered HbA1c, body weight, and systolic BP compared with placebo in patients with and without CV disease history or risk factors. Placebo-subtracted HbA1c reductions with canagliflozin 100 and 300 mg were similar in patients with a history of CV disease (−0.95 and −1.07%) versus no history of CV disease (−0.71 and −0.90%), history of hypertension (−0.72 and −0.89%) versus no history of hypertension (−0.73 and −0.95%), baseline statin use (−0.77 and −0.99%) versus no statin use (−0.69 and −0.85%), and 0–1 CV risk factor (−0.72 and −0.87%) versus ≥2 CV risk factors (−0.74 and −1.02%). Similar body weight and systolic BP reductions were seen with canagliflozin versus placebo across subgroups. The incidence of AEs, AEs leading to discontinuation, and serious AEs was similar across subgroups.

Conclusions

The efficacy and safety of canagliflozin were generally consistent across subgroups of patients with T2DM and varying degrees of CV disease history or risk factors.

Trial registration numbers and dates ClinicalTrials.gov: NCT01081834, 4 March 2010; NCT01106625, 1 April 2010; NCT01106677, 1 April 2010; NCT01106690, 1 April 2010

Electronic supplementary material

The online version of this article (doi:10.1186/s12933-017-0517-7) contains supplementary material, which is available to authorized users.

Interpretation of cardiovascular outcome trials in type 2 diabetes needs a multiaxial approach

In cardiovascular (CV) diabetology a "one-size fits-all" approach needs caution as vasculopathy and CV manifestations in patients with type 2 diabetes (T2D) with short disease duration are different as compared to those with longer duration. This is of relevance when interpreting results of CV outcome trials as responses to any intervention aimed to reduce CV risk might be different in patients with established vasculopathy as compared to those without, where also the duration of the intervention may play a role. Additionally, the mode-of-action of the intervention and its assumed time to peak CV risk modulation need to be taken into account: an intervention with possibly immediate effects, like on blood pressure or other direct functional dynamic parameters such as endothelial function or renal hemodynamics, could likely provide a meaningful impact on CV outcomes over a shorter time span than interventions that primarily target pathways that work on atherosclerotic processes, organ-remodelling, or vessel integrity. We are now faced with CV outcome results to interpret from a plethora of outcomes trials in T2D, some of which are testing the CV risk modulation predominantly beyond glucose lowering, e.g., as is the case for several trials testing the newer therapy classes di-peptidyl peptidase-4 inhibitors, glucagon-like protein-1 receptor analogues and sodium glucose co-transporter-2 inhibitors, and this paper reviews the data that support a call for a multiaxial approach to interpret these results.

SGLT-2 inhibitors and cardiovascular risk: proposed pathways and review of ongoing outcome trials

Given the multi-faceted pathogenesis of atherosclerosis in type 2 diabetes mellitus (T2DM), it is likely that interventions to mitigate this risk must address cardiovascular (CV) risk factors beyond glucose itself. Sodium glucose cotransporter-2 (SGLT-2) inhibitors are newer antihyperglycaemic agents with apparent multiple effects. Inherent in their mode of action to decrease glucose reabsorption by the kidneys by increasing urinary glucose excretion, these agents improve glycaemic control independent of insulin secretion with a low risk of hypoglycaemia. In this review, we outline those CV risk factors that this class appears to influence and provide the design features and trial characteristics of six ongoing outcome trials involving more than 41,000 individuals with T2DM. Those risk factors beyond glucose that can potentially be modulated positively with SGLT-2 inhibitors include blood pressure, weight, visceral adiposity, hyperinsulinaemia, arterial stiffness, albuminuria, circulating uric acid levels and oxidative stress. On the other hand, small increases in low-density lipoprotein (LDL)-cholesterol levels have also been observed for the class, which theoretically might offset some of these benefits. The potential translational impact of these effects is being tested with outcome trials, also reviewed in this article, powered to assess both macrovascular as well as certain microvascular outcomes in T2DM. These are expected to begin to report in late 2015.

Metabolic Syndrome and its Profound Effect on Prevalence of Ischemic Stroke

Ischemic stroke represents a leading cause of death worldwide and the leading cause of disability in the United States. Greater than 8% of all deaths are attributed to ischemic stroke. This rate is consistent with the heightened burden of cardiovascular disease deaths. Treatments for acute ischemic stroke remain limited to tissue plasminogen activator and mechanical thrombolysis, both of which require significant medical expertise and can only be applied to a select number of patients based on time of presentation, imaging, and absence of contraindications. Over 1,000 compounds that were successful in treating ischemic stroke in animal models have failed to correlate to success in clinical trials. The search for alternative treatments is ongoing, drawing greater attention to the importance of preclinical models that more accurately represent the clinical population through incorporation of common risk factors. This work reviews the contribution of these commonly observed risk factors in the clinical population highlighting both the pathophysiology as well as current clinical diagnosis and treatment standards. We also highlight future potential therapeutic targets, areas requiring further investigation, and recent changes in best-practice clinical care.

NF-kappaB binding activity and pro-inflammatory cytokines expression correlate with body mass index but not glycosylated hemoglobin in Chinese population

AIMS

Chronic inflammation is linked to type 2 diabetes (T2DM), so we investigated correlations between obesity, blood glucose levels, and inflammation in T2DM patients.

METHODS

Peripheral blood mononuclear cells (PBMCs) were collected from 40 T2DM patients (27 men, 13 women; mean age 49.63 years), and 10 non-diabetic controls (all men; mean age 38.60 years). Inflammation was measured as DNA-binding activity of nuclear factor kappaB (NF-kappaB), a key transcription factor in inflammation. Protein levels of NF-kappaB subunit p65, and NF-kappaB inhibitor IkappaBalpha were assessed by Western blot. Transcript levels for p65, IkappaBalpha, and the NF-kappaB target genes TNF-alpha, MMP-9, IL-6, IL-8, and IL-18 were measured by real-time PCR. Body mass index (BMI) and glycohemoglobin were measured for all the subjects.

RESULTS

NF-kappaB DNA-binding activity, p65 and IkappaBalpha protein levels, and expression of IL-6, TNFalpha and MMP-9 were significantly higher in PBMCs from T2DM patients, than from non-diabetic controls. NF-kappaB binding was significantly positively associated with both BMI and homeostasis model assessment of insulin resistance (HOMA-IR).

CONCLUSIONS

Inflammation was observed in PBMCs in T2DM patients in a Chinese population, and correlated independently with obesity and blood glucose levels. Lack of correlation with glycohemoglobin suggested that moderate-term blood glucose control did not mitigate inflammation.