52 resultados para Vascular Stiffness
Resumo:
Cardiovascular disease (CVD) prevalence at a global level is predicted to increase substantially over the next decade due to the increasing ageing population and incidence of obesity. Hence, there is an urgent requirement to focus on modifiable contributors to CVD risk, including a high dietary intake of saturated fatty acids (SFA). As an important source of SFA in the UK diet, milk and dairy products are often targeted for SFA reduction. The current paper acknowledges that milk is a complex food and that simply focusing on the link between SFA and CVD risk overlooks the other beneficial nutrients of dairy foods. The body of existing prospective evidence exploring the impact of milk and dairy consumption on risk factors for CVD is reviewed. The current paper highlights that high milk consumption may be beneficial to cardiovascular health, while illustrating that the evidence is less clear for cheese and butter intake. The option of manipulating the fatty acid profile of ruminant milk is discussed as a potential dietary strategy for lowering SFA intake at a population level. The review highlights that there is a necessity to perform more well-controlled human intervention-based research that provides a more holistic evaluation of fat-reduced and fat-modified dairy consumption on CVD risk factors including vascular function, arterial stiffness, postprandial lipaemia and markers of inflammation. Additionally, further research is required to investigate the impact of different dairy products and the effect of the specific food matrix on CVD development.
Resumo:
Abstract BACKGROUND: Cinnamon has been shown to delay gastric emptying of a high-carbohydrate meal and reduce postprandial glycemia in healthy adults. However, it is dietary fat which is implicated in the etiology and is associated with obesity, type 2 diabetes and cardiovascular disease. We aimed to determine the effect of 3 g cinnamon (Cinnamomum zeylanicum) on GE, postprandial lipemic and glycemic responses, oxidative stress, arterial stiffness, as well as appetite sensations and subsequent food intake following a high-fat meal. METHODS: A single-blind randomized crossover study assessed nine healthy, young subjects. GE rate of a high-fat meal supplemented with 3 g cinnamon or placebo was determined using the 13C octanoic acid breath test. Breath, blood samples and subjective appetite ratings were collected in the fasted and during the 360 min postprandial period, followed by an ad libitum buffet meal. Gastric emptying and 1-day fatty acid intake relationships were also examined. RESULTS: Cinnamon did not change gastric emptying parameters, postprandial triacylglycerol or glucose concentrations, oxidative stress, arterial function or appetite (p < 0.05). Strong relationships were evident (p < 0.05) between GE Thalf and 1-day palmitoleic acid (r = -0.78), eiconsenoic acid (r = -0.84) and total omega-3 intake (r = -0.72). The ingestion of 3 g cinnamon had no effect on GE, arterial stiffness and oxidative stress following a HF meal. CONCLUSIONS: 3 g cinnamon did not alter the postprandial response to a high-fat test meal. We find no evidence to support the use of 3 g cinnamon supplementation for the prevention or treatment of metabolic disease. Dietary fatty acid intake requires consideration in future gastrointestinal studies.
Resumo:
The glycoprotein VI (GPVI)-FcR gamma-chain complex initiates powerful activation of platelets by the subendothelial matrix proteins collagen and laminin through an immunoreceptor tyrosine-based activation motif (ITAM)-regulated signaling pathway. ITAMs are characterized by two YxxL sequences separated by 6-12 amino acids and are found associated with several classes of immunoglobulin (Ig) and C-type lectin receptors in hematopoietic cells, including Fc receptors. Cross-linking of the Ig GPVI leads to phosphorylation of two conserved tyrosines in the FcR gamma-chain ITAM by Src family tyrosine kinases, followed by binding and activation of the tandem SH2 domain-containing Syk tyrosine kinase and stimulation of a downstream signaling cascade that culminates in activation of phospholipase Cgamma2 (PLCgamma2). In contrast, the C-type lectin receptor CLEC-2 mediates powerful platelet activation through Src and Syk kinases, but regulates Syk through a novel dimerization mechanism via a single YxxL motif known as a hemITAM. CLEC-2 is a receptor for podoplanin, which is expressed at high levels in several tissues, including type 1 lung alveolar cells, lymphatic endothelial cells, kidney podocytes and some tumors, but is absent from vascular endothelial cells and platelets. In this article, we compare the mechanism of platelet activation by GPVI and CLEC-2 and consider their functional roles in hemostasis and other vascular processes, including maintenance of vascular integrity, angiogenesis and lymphogenesis.
Resumo:
PURPOSE: Consumption of sugar-reformulated products (commercially available foods and beverages that have been reduced in sugar content through reformulation) is a potential strategy for lowering sugar intake at a population level. The impact of sugar-reformulated products on body weight, energy balance (EB) dynamics and cardiovascular disease risk indicators has yet to be established. The REFORMulated foods (REFORM) study examined the impact of an 8-week sugar-reformulated product exchange on body weight, EB dynamics, blood pressure, arterial stiffness, glycemia and lipemia. METHODS: A randomized, controlled, double-blind, crossover dietary intervention study was performed with fifty healthy normal to overweight men and women (age 32.0 ± 9.8 year, BMI 23.5 ± 3.0 kg/m2) who were randomly assigned to consume either regular sugar or sugar-reduced foods and beverages for 8 weeks, separated by 4-week washout period. Body weight, energy intake (EI), energy expenditure and vascular markers were assessed at baseline and after both interventions. RESULTS: We found that carbohydrate (P < 0.001), total sugars (P < 0.001) and non-milk extrinsic sugars (P < 0.001) (% EI) were lower, whereas fat (P = 0.001) and protein (P = 0.038) intakes (% EI) were higher on the sugar-reduced than the regular diet. No effects on body weight, blood pressure, arterial stiffness, fasting glycemia or lipemia were observed. CONCLUSIONS: Consumption of sugar-reduced products, as part of a blinded dietary exchange for an 8-week period, resulted in a significant reduction in sugar intake. Body weight did not change significantly, which we propose was due to energy compensation.
Resumo:
Background: The beneficial cardiovascular effects of vegetables may be underpinned by their high inorganic nitrate content. Objective: We sought to examine the effects of a 6-wk once-daily intake of dietary nitrate (nitrate-rich beetroot juice) compared with placebo intake (nitrate-depleted beetroot juice) on vascular and platelet function in untreated hypercholesterolemics. Design: A total of 69 subjects were recruited in this randomized, double-blind, placebo-controlled parallel study. The primary endpoint was the change in vascular function determined with the use of ultrasound flow-mediated dilatation (FMD). Results: Baseline characteristics were similar between the groups, with primary outcome data available for 67 patients. Dietary nitrate resulted in an absolute increase in the FMD response of 1.1% (an ∼24% improvement from baseline) with a worsening of 0.3% in the placebo group (P < 0.001). A small improvement in the aortic pulse wave velocity (i.e., a decrease of 0.22 m/s; 95% CI: −0.4, −0.3 m/s) was evident in the nitrate group, showing a trend (P = 0.06) to improvement in comparison with the placebo group. Dietary nitrate also caused a small but significant reduction (7.6%) in platelet-monocyte aggregates compared with an increase of 10.1% in the placebo group (P = 0.004), with statistically significant reductions in stimulated (ex vivo) P-selectin expression compared with the placebo group (P < 0.05) but no significant changes in unstimulated expression. No adverse effects of dietary nitrate were detected. The composition of the salivary microbiome was altered after the nitrate treatment but not after the placebo treatment (P < 0.01). The proportions of 78 bacterial taxa were different after the nitrate treatment; of those taxa present, 2 taxa were responsible for >1% of this change, with the proportions of Rothia mucilaginosa trending to increase and Neisseria flavescens (P < 0.01) increased after nitrate treatment relative to after placebo treatment. Conclusions: Sustained dietary nitrate ingestion improves vascular function in hypercholesterolemic patients. These changes are associated with alterations in the oral microbiome and, in particular, nitrate-reducing genera. Our findings provide additional support for the assessment of the potential of dietary nitrate as a preventative strategy against atherogenesis in larger cohorts. This trial was registered at clinicaltrials.gov as NCT01493752.
Resumo:
The failing heart is characterized by complex tissue remodelling involving increased cardiomyocyte death, and impairment of sarcomere function, metabolic activity, endothelial and vascular function, together with increased inflammation and interstitial fibrosis. For years, therapeutic approaches for heart failure (HF) relied on vasodilators and diuretics which relieve cardiac workload and HF symptoms. The introduction in the clinic of drugs interfering with beta-adrenergic and angiotensin signalling have ameliorated survival by interfering with the intimate mechanism of cardiac compensation. Current therapy, though, still has a limited capacity to restore muscle function fully, and the development of novel therapeutic targets is still an important medical need. Recent progress in understanding the molecular basis of myocardial dysfunction in HF is paving the way for development of new treatments capable of restoring muscle function and targeting specific pathological subsets of LV dysfunction. These include potentiating cardiomyocyte contractility, increasing cardiomyocyte survival and adaptive hypertrophy, increasing oxygen and nutrition supply by sustaining vessel formation, and reducing ventricular stiffness by favourable extracellular matrix remodelling. Here, we consider drugs such as omecamtiv mecarbil, nitroxyl donors, cyclosporin A, SERCA2a (sarcoplasmic/endoplasmic Ca(2 +) ATPase 2a), neuregulin, and bromocriptine, all of which are currently in clinical trials as potential HF therapies, and discuss novel molecular targets with potential therapeutic impact that are in the pre-clinical phases of investigation. Finally, we consider conceptual changes in basic science approaches to improve their translation into successful clinical applications.
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Synthetic tripeptide based noncytotoxic hydrogelators have been discovered for releasing an anticancer drug at physiological pH and temparature. Interestingly, gel stiffness, drug release capacity and proteolytic stability of these hydrogels have been successfully modulated by incorporating D-amino acid residues, indicating their potential use for drug delivery in the future.