Fibrinogen and future cardiovascular disease in people with diabetes: aetiological associations and risk prediction using individual participant data from nine community-based prospective cohort studies

Selective estrogen receptor α and β antagonist aggravate cardiovascular dysfunction in type 2 diabetic ovariectomized female rats

OBJECTIVES

Type 2 diabetes (T2D) is a major risk factor for cardiovascular disorders (CVD), characterized by pathological diastolic as well as systolic dysfunction, ventricular dilation, and cardiomyocyte hypertrophy. CVD is the main cause of death in postmenopausal women. Estradiol (E2) has protective effects on cardiovascular function. The biological effects of E2 are mainly mediated by classical estrogen receptors (ERs). The present study aimed to investigate the cardioprotective effects of classical ERs in ovariectomized (OVX) diabetic female rats.

METHODS

T2D was induced in female rats by high-fat diet feeding along with a low dose of streptozotocin. Then diabetic animals were divided into eight groups: Sham-control, OVX, OVX + Vehicle (Veh), OVX + E2, OVX + E2 + MPP (ERα antagonist), OVX + E2 + PHTPP (ERβ antagonist), OVX + E2 + Veh, OVX + E2 + MPP + PHTPP. Animals received E2, MPP, and PHTPP every four days for 28 days. At the end blood was collected, serum separated, and used for biochemical parameters. Heart tissue was used for cardiac angiotensin II and cytokines measurement.

RESULTS

E2 treatment improved the metabolic disorders caused by T2D, and its receptor antagonists intensified the effects of T2D on the metabolic status. Also, E2 therapy decreased cardiac inflammatory cytokines, and MPP and PHTPP increased cardiac inflammation by increasing TNF-α and IL-6 and decreasing IL-10.

CONCLUSIONS

Classical ERs have protective effects on diabetic hearts by improving the metabolic status and inflammatory balance.

Consumption of Plant Foods and Its Association with Cardiovascular Disease Risk Profile in South Africans at High-Risk of Type 2 Diabetes Mellitus

We assessed the distribution and association of cardiovascular disease (CVD) risk factors by plant foods consumption in individuals at high-risk for type 2 diabetes mellitus. This cross-sectional study utilized baseline data of 693 participants in the South African Diabetes Prevention Programme. Participants underwent a physical examination, biochemical analysis, and dietary assessment using a single non-quantified 24-h recall. Group comparisons were conducted to explore the distribution and associations of common CVD risk factors by plant foods consumption. The mean age of the participants was 51 years, with 81% being females. Consumers of yellow-coloured vitamin A-rich vegetables and tubers and maize had significantly lower systolic blood pressure, fasting insulin, low-density lipoprotein cholesterol, triglycerides, and fibrinogen levels. Cereals consumption increased the likelihood of obesity (OR = 1.72 95% CI [1.09, 2.70] p = 0.019) while the consumption of white roots and tubers decreased the likelihood of obesity (AOR = 0.64 95% CI [0.41, 1.00] p = 0.048). This study reported the consumption of some healthy plant foods with lower levels of, and decreased risk for, some CVD risk factors. A further in-depth investigation is needed to understand these associations.

Hypofibrinolysis in type 2 diabetes and its clinical implications: from mechanisms to pharmacological modulation

A prothrombotic state is a typical feature of type 2 diabetes mellitus (T2DM). Apart from increased platelet reactivity, endothelial dysfunction, hyperfibrinogenemia, and hypofibrinolysis are observed in T2DM. A variety of poorly elucidated mechanisms behind impaired fibrinolysis in this disease have been reported, indicating complex associations between platelet activation, fibrin formation and clot structure, and fibrinolysis inhibitors, in particular, elevated plasminogen antigen inhibitor-1 levels which are closely associated with obesity. Abnormal fibrin clot structure is of paramount importance for relative resistance to plasmin-mediated lysis in T2DM. Enhanced thrombin generation, a proinflammatory state, increased release of neutrophil extracellular traps, elevated complement C3, along with posttranslational modifications of fibrinogen and plasminogen have been regarded to contribute to altered clot structure and impaired fibrinolysis in T2DM. Antidiabetic agents such as metformin and insulin, as well as antithrombotic agents, including anticoagulants, have been reported to improve fibrin properties and accelerate fibrinolysis in T2DM. Notably, recent evidence shows that hypofibrinolysis, assessed in plasma-based assays, has a predictive value in terms of cardiovascular events and cardiovascular mortality in T2DM patients. This review presents the current data on the mechanisms underlying arterial and venous thrombotic complications in T2DM patients, with an emphasis on hypofibrinolysis and its impact on clinical outcomes. We also discuss potential modulators of fibrinolysis in the search for optimal therapy in diabetic patients.

GlycA for long-term outcome in T2DM secondary prevention

AIMS

Glycosylated acetyls (GlycA), a systemic marker of inflammation, were associated both with incident type 2 diabetes mellitus (T2DM) and incident cardiovascular (CV) disease. This study evaluates the predictive value of GlycA for long-term survival in patients with T2DM and peripheral artery disease (PAD).

METHODS

GlycA (mmol/l) levels were measured by nuclear magnetic resonance spectroscopy in a cross-sectional cohort of patients with PAD (n = 319). Both all-cause and CV mortality were evaluated after a follow-up of 9.0 (IQR 6.5-9.5) years. During the follow-up 117 patients died, of those 64 events were of CV origin (PAD-T2DM subgroup: all-cause mortality n = 60, CV-mortality n = 32).

RESULTS

PAD-T2DM showed a tendency towards a worse CV risk factor profile and a higher percentage of known coronary artery disease (24.9% vs 43.5%, p < 0.001). GlycA levels were higher in PAD-T2DM (1.6 ± 0.2 vs. 1.53 ± 0.18, p = 0.002). GlycA predicted all-cause mortality after multivariable adjustment for traditional CV risk factors (HR for 1 SD increase 1.51, 95% confidence interval 1.03-2.19) in PAD-T2DM, while no association could be seen with CV-mortality (1.22, 0.73-2.06).

CONCLUSIONS

GlycA was capable of predicting long-term outcome in PAD patients with T2DM. Thus, GlycA might reflect the added inflammatory burden of T2DM in systemic atherosclerosis.

Biomarkers of cardiovascular disease: contributions to risk prediction in individuals with diabetes

Cardiovascular disease is a leading cause of death, especially in individuals with diabetes mellitus, whose risk of morbidity and mortality due to cardiovascular disease is markedly increased compared with the general population. There has been growing interest in the identification of biomarkers of cardiovascular disease in people with diabetes. The present review focuses on the current and potential contributions of these biomarkers to predicting cardiovascular risk in individuals with diabetes. At present, certain biomarkers and biomarker combinations can lead to modest improvements in the prediction of cardiovascular disease in diabetes beyond traditional cardiovascular risk factors. Emerging technologies may enable the discovery of novel biomarkers and generate new information about known biomarkers (such as new combinations of biomarkers), which could lead to significant improvements in cardiovascular disease risk prediction. A critical question, however, is whether improvements in risk prediction will affect processes of care and decision making in clinical practice, as this will be required to achieve the ultimate goal of improving clinical outcomes in diabetes.

Comparison of non-traditional biomarkers, and combinations of biomarkers, for vascular risk prediction in people with type 2 diabetes: The Edinburgh Type 2 Diabetes Study

BACKGROUND AND AIMS

We aimed at comparing the impact of multiple non-traditional biomarkers (ankle brachial pressure index (ABI), N-terminal pro-brain natriuretic peptide (NT-proBNP), high sensitivity cardiac troponin (hs-cTnT), gamma-glutamyl transpeptidase (GGT) and four markers of systemic inflammation), both individually and in combination, on cardiovascular risk prediction, over and above traditional risk factors incorporated in the QRISK2 score, in older people with type 2 diabetes.

METHODS

We conducted a prospective study of 1066 men and women aged 60-75 years with type 2 diabetes mellitus, living in Lothian, Scotland.

RESULTS

After 8 years, 205 cardiovascular events occurred. Higher levels of hs-cTNT and NT-proBNP and lower ABI at baseline were associated with increased risk of CV events, independently of traditional risk factors (basic model). The C statistic of 0.722 (95% CI 0.681, 0.763) for the basic model increased on addition of individual biomarkers, most markedly for hs-cTnT (0.732; 0.690, 0.774)). Models including different combinations of biomarkers had even greater C statistics, with the highest for ABI, hs-cTnT and GGT combined (0.740; 0.699, 0.781).

CONCLUSIONS

Individually, hs-cTnT appeared to be the most promising biomarker in terms of improving vascular risk prediction in people with type 2 diabetes, over and above traditional risk factors incorporated in the QRISK2 score. Combining several non-traditional biomarkers added further predictive value, and this approach merits further investigation when developing cost effective risk prediction tools for use in clinical practice.

Genetic Modifiers of the p53 Pathway

The tumor suppressor gene TP53 is the most frequently mutated gene in human cancer; this gene is subject to inactivation by mutation or deletion in >50% of sporadic cancers. Genes that encode proteins that regulate p53 function, such as MDM2, MDM4, and CDKN2A (p14(ARF)) are also frequently altered in tumors, and it is generally believed that the p53 pathway is likely to be inactivated by mutation in close to 100% of human tumors. Unlike most other cancer-relevant signaling pathways, some of the genes in the p53 pathway contain functionally significant single nucleotide polymorphisms (SNPs) that alter the amplitude of signaling by this protein. These variants, thus, have the potential to impact cancer risk, progression, and the efficacy of radiation and chemotherapy. In addition, the p53 pathway plays a role in other biological processes, including metabolism and reproductive fitness, so these variants have the potential to modify other diseases as well. Here we have chosen five polymorphisms in three genes in the p53 pathway for review, two in TP53, two in MDM2, and one in MDM4. These five variants were selected based on the quality and reproducibility of functional data associated with them, as well as the convincingness of epidemiological data in support of their association with disease. We also highlight two other polymorphisms that may affect p53 signaling, but for which functional or association data are still forthcoming (KITLG and ANRIL). Finally, we touch on three questions regarding genetic modifiers of the p53 pathway: Why did these variants arise? Were they under selection pressure? And, is there compelling evidence to support genotyping these variants to better predict disease risk and prognosis?

Cardiovascular risk profiles in Type 2 diabetes and the impact of geographical setting

Cardiovascular (CV) disease is a leading morbidity and mortality in Type 2 diabetes (T2DM). Previous studies have shown geographic differences in the prevalence of CV and renal diseases. A literature review of longitudinal (≥5 years) studies including ≥1000 T2DM patients and reporting CV endpoints was performed to compare risk profiles. Key differences between geographies included a relatively higher prevalence of microalbuminuria in East Asian relative to North American and European patients, which in turn is an important CV risk factor. Patients from East Asia also have a relatively higher incidence of stroke and lower incidence of coronary heart disease. Overall, there are differences in CV risk in T2DM patients between different regions and that long-term studies from Africa, the Middle East and Latin America are lacking.

Circulating inflammatory markers and the risk of vascular complications and mortality in people with type 2 diabetes and cardiovascular disease or risk factors: the ADVANCE study

C-reactive protein (CRP), fibrinogen, and interleukin-6 (IL-6) are associated with cardiovascular disease (CVD) and death in general populations. However, studies of these factors in type 2 diabetes are limited. We studied their associations with the risk of major macrovascular events, microvascular complications, and mortality in patients with type 2 diabetes who participated in the Action in Diabetes and Vascular Disease: Preterax and Diamicron Modified Release Controlled Evaluation (ADVANCE) Study. Plasma CRP, fibrinogen, and IL-6 levels were determined in a case-cohort study (n = 3,865) nested within the 11,140 men and women with type 2 diabetes and baseline CVD or risk factors in the ADVANCE Study. All three biomarkers of inflammation were associated with an increased risk of macrovascular events and death in analyses adjusted for age, sex, and treatment groups. After further adjustment, only IL-6 was an independent predictor of macrovascular events (hazard ratio per SD increase 1.37 [95% CI 1.24-1.51]) and death (1.35 [1.23-1.49]). IL-6 significantly improved the prediction of macrovascular events and death. After adjustment, none of the markers predicted microvascular complications. We conclude that IL-6 levels, but not CRP or fibrinogen levels, add significantly to the prediction of macrovascular events and mortality in individuals with type 2 diabetes who have baseline CVD or risk factors.

Diabetes mellitus and inflammation

Type 2 diabetes mellitus (T2DM) is increasingly common worldwide. Related complications account for increased morbidity and mortality, and enormous healthcare spending. Knowledge of the pathophysiological derangements involved in the occurrence of diabetes and related complications is critical for successful prevention and control solutions. Epidemiologic studies have established an association between inflammatory biomarkers and the occurrence of T2DM and complications. Adipose tissue appears to be a major site of production of those inflammatory biomarkers, as a result of the cross-talk between adipose cells, macrophages, and other immune cells that infiltrate the expanding adipose tissue. The triggering mechanisms of the inflammation in T2DM are still ill-understood. Inflammatory response likely contributes to T2DM occurrence by causing insulin resistance, and is in turn intensified in the presence of hyperglycemia to promote long-term complications of diabetes. Targeting inflammatory pathways could possibly be a component of the strategies to prevent and control diabetes and related complications.