The Role of Inflammation in Diabetes: Current Concepts and Future Perspectives

Diabetes is a complex metabolic disorder affecting the glucose status of the human body. Chronic hyperglycaemia related to diabetes is associated with end organ failure. The clinical relationship between diabetes and atherosclerotic cardiovascular disease is well established. This makes therapeutic approaches that simultaneously target diabetes and atherosclerotic disease an attractive area for research. The majority of people with diabetes fall into two broad pathogenetic categories, type 1 or type 2 diabetes. The role of obesity, adipose tissue, gut microbiota and pancreatic beta cell function in diabetes are under intensive scrutiny with several clinical trials to have been completed while more are in development. The emerging role of inflammation in both type 1 and type 2 diabetes (T1D and T1D) pathophysiology and associated metabolic disorders, has generated increasing interest in targeting inflammation to improve prevention and control of the disease. After an extensive review of the possible mechanisms that drive the metabolic pattern in T1D and T2D and the inflammatory pathways that are involved, it becomes ever clearer that future research should focus on a model of combined suppression for various inflammatory response pathways

Development of a risk score for early saphenous vein graft failure: An individual patient data meta-analysis.

OBJECTIVES: Early saphenous vein graft (SVG) occlusion is typically attributed to technical factors. We aimed at exploring clinical, anatomical, and operative factors associated with the risk of early SVG occlusion (within 12 months postsurgery). METHODS: Published literature in MEDLINE was searched for studies reporting the incidence of early SVG occlusion. Individual patient data (IPD) on early SVG occlusion were used from the SAFINOUS-CABG Consortium. A derivation (n = 1492 patients) and validation (n = 372 patients) cohort were used for model training (with 10-fold cross-validation) and external validation respectively. RESULTS: In aggregate data meta-analysis (48 studies, 41,530 SVGs) the pooled estimate for early SVG occlusion was 11%. The developed IPD model for early SVG occlusion, which included clinical, anatomical, and operative characteristics (age, sex, dyslipidemia, diabetes mellitus, smoking, serum creatinine, endoscopic vein harvesting, use of complex grafts, grafted target vessel, and number of SVGs), had good performance in the derivation (c-index = 0.744; 95% confidence interval [CI], 0.701-0.774) and validation cohort (c-index = 0.734; 95% CI, 0.659-0.809). Based on this model. we constructed a simplified 12-variable risk score system (SAFINOUS score) with good performance for early SVG occlusion (c-index = 0.700, 95% CI, 0.684-0.716). CONCLUSIONS: From a large international IPD collaboration, we developed a novel risk score to assess the individualized risk for early SVG occlusion. The SAFINOUS risk score could be used to identify patients that are more likely to benefit from aggressive treatment strategies

A novel machine learning-derived radiotranscriptomic signature of perivascular fat improves cardiac risk prediction using coronary CT angiography

Background: Coronary inflammation induces dynamic changes in the balance between water and lipid content in perivascular adipose tissue (PVAT), as captured by perivascular Fat Attenuation Index (FAI) in standard coronary CT angiography (CCTA). However, inflammation is not the only process involved in atherogenesis and we hypothesized that additional radiomic signatures of adverse fibrotic and microvascular PVAT remodelling, may further improve cardiac risk prediction. Methods and results: We present a new artificial intelligence-powered method to predict cardiac risk by analysing the radiomic profile of coronary PVAT, developed and validated in patient cohorts acquired in three different studies. In Study 1, adipose tissue biopsies were obtained from 167 patients undergoing cardiac surgery, and the expression of genes representing inflammation, fibrosis and vascularity was linked with the radiomic features extracted from tissue CT images. Adipose tissue wavelet-transformed mean attenuation (captured by FAI) was the most sensitive radiomic feature in describing tissue inflammation (TNFA expression), while features of radiomic texture were related to adipose tissue fibrosis (COL1A1 expression) and vascularity (CD31 expression). In Study 2, we analysed 1391 coronary PVAT radiomic features in 101 patients who experienced major adverse cardiac events (MACE) within 5 years of having a CCTA and 101 matched controls, training and validating a machine learning (random forest) algorithm (fat radiomic profile, FRP) to discriminate cases from controls (C-statistic 0.77 [95%CI: 0.62–0.93] in the external validation set). The coronary FRP signature was then tested in 1575 consecutive eligible participants in the SCOT-HEART trial, where it significantly improved MACE prediction beyond traditional risk stratification that included risk factors, coronary calcium score, coronary stenosis, and high-risk plaque features on CCTA (Δ[C-statistic] = 0.126, P  Conclusion: The CCTA-based radiomic profiling of coronary artery PVAT detects perivascular structural remodelling associated with coronary artery disease, beyond inflammation. A new artificial intelligence (AI)-powered imaging biomarker (FRP) leads to a striking improvement of cardiac risk prediction over and above the current state-of-the-art. </p

Adipose tissue-derived WNT5A regulates vascular redox signaling in obesity via USP17//RAC1-mediated activation of NADPH oxidases

Obesity is associated with changes in the secretome of adipose tissue (AT), which affects the vasculature through endocrine and paracrine mechanisms. Wingless-related integration site 5A (WNT5A) and secreted frizzled-related protein 5 (SFRP5), adipokines that regulate noncanonical Wnt signaling, are dysregulated in obesity. We hypothesized that WNT5A released from AT exerts endocrine and paracrine effects on the arterial wall through noncanonical RAC1-mediated Wnt signaling. In a cohort of 1004 humans with atherosclerosis, obesity was associated with increased WNT5A bioavailability in the circulation and the AT, higher expression of WNT5A receptors Frizzled 2 and Frizzled 5 in the human arterial wall, and increased vascular oxidative stress due to activation of NADPH oxidases. Plasma concentration of WNT5A was elevated in patients with coronary artery disease compared to matched controls and was independently associated with calcified coronary plaque progression. We further demonstrated that WNT5A induces arterial oxidative stress and redox-sensitive migration of vascular smooth muscle cells via Frizzled 2–mediated activation of a previously uncharacterized pathway involving the deubiquitinating enzyme ubiquitin-specific protease 17 (USP17) and the GTPase RAC1. Our study identifies WNT5A and its downstream vascular signaling as a link between obesity and vascular disease pathogenesis, with translational implications in humans

Mechanisms of testosterone deficiency-related endothelial dysfunction

Evidence from clinical studies suggests that patients with low testosterone levels are at increased cardiovascular disease risk. Even though the exact mechanisms remain poorly understood, a low plasma testosterone level is associated with a pro-atherogenic lipid profile, insulin resistance and increased levels of pro-inflammatory mediators and vascular dysfunction, which is typically observed in patients with hypogonadism. Furthermore, recent evidence suggests that testosterone deficiency has also direct adverse effects on the endothelium and nitric oxide (NO) bioavailability. Observations from studies in patients with hypogonadal hypogonadism imply that the mechanisms of endothelial dysfunction related to testosterone deficiency may involve changes in asymmetric dimethylarginine (ADMA) levels, a known endogenous inhibitor of NO synthase. Evidence suggests that testosterone replacement therapy is not only a safe but also an effective means to reduce atherosclerotic risk and reverse endothelial dysfunction in patients with hypogonadal hypogonadism. Further research in the field is expected to clarify whether changes in ADMA metabolism constitute the central mechanism through which a low testosterone level leads to endothelial dysfunction. Keywords: Testosterone, Asymmetric dimethylarginine, Endothelial dysfunction, Nitric oxide, Hypogonadis

The molecular mechanisms of obesity paradox

Clinical observations suggest a complex relationship between human obesity and cardiovascular disease. Whilst abdominal (visceral) adiposity leads to deleterious metabolic disturbances, subcutaneous fat accumulation has a benign effect on cardiometabolic risk. Notably, an accumulating body of evidence paradoxically links increased body mass index with a better prognosis in patients with established cardiovascular disease, a finding that has been termed the `obesity paradox&apos;. Whilst this is now acknowledged to be an epidemiological finding, a metabolically healthy obese group associated with low cardiovascular risk has also been identified. The current concept of adipose tissue (AT) biology suggests that AT expansion is feasible without accompanying adipocyte dysfunction. A metabolically healthy obese phenotype can be promoted by exercise, but is also linked with intrinsic AT molecular characteristics such as efficient fat storage and lipid droplet formation, high adipogenesis capacity, low extracellular matrix fibrosis, angiogenesis potential, adipocyte browning and low macrophages infiltration/activation. Such features are associated with a secretomic profile of human AT which is protective for the cardiovascular system. In the present review, we summarize the existing knowledge on the molecular mechanisms underlying the `obesity paradox&apos; and whether fatness can be healthy too

Unravelling the “adipokine paradox”: When the classic proatherogenic adipokine leptin is deemed the beneficial one

Adipokines released by adipose tissue have been recognised as important players in the development of cardiovascular disease. Leptin is a well-studied adipokine with an important role in body metabolism and energy expenditure and leptin-deficiency or deficient leptin signalling results in excessive obesity and type 2 diabetes. Studies in cells and animal models support that leptin has a pro-atherogenic potential and exerts pro-hypertrophic effects on the heart. However, recent basic and clinical evidence suggests that leptin may also have a beneficial role in cardiovascular physiology. Notably, clinical studies have failed to convincingly link leptin with increased cardiovascular disease risk. We herein summarise the role of leptin in cardiovascular disease as another example of the `adipokine paradox&apos; and discuss the complexity in using serum adipokine levels as biomarkers in cardiovascular disease. (C) 2015 Elsevier Ireland Ltd. All rights reserved