The MEDGICarb-Study: Design of a multi-center randomized controlled trial to determine the differential health-promoting effects of low- and high-glycemic index Mediterranean-style eating patterns

Adults with central adiposity and other features of the metabolic syndrome have a markedly elevated risk of developing type 2 diabetes (T2D) and cardiovascular disease (CVD). A Mediterranean-style healthy eating pattern (MED-HEP) and consumption of foods with a lower glycemic index (GI) are potential dietary approaches to curb the T2D and CVD epidemic. However, experimental evidence of the effectiveness of MED-HEP and of the contribution of GI towards improving indices of glucose homeostasis, especially among non-diabetic people, are lacking. Therefore, we developed the MedGI-Carb trial, a multi-center (Italy, Sweden, and United States) intervention in adults with at least two components of the metabolic syndrome (elevated waist circumference + one other component) that aims to improve markers of glucose homeostasis through dietary modification. All participants were randomized to consume an isocaloric high- or low-GI MED-HEP for 12 weeks. We hypothesized that indexes of insulinemia (primary outcome: postprandial insulin and glucose after standardized breakfast and lunch; secondary outcomes: fasting plasma glucose and insulin, HbA1c, 24-h continuous glucose monitoring) would be improved more with the low-GI versus the high-GI MED-HEP. Additionally, we hypothesized that consumption of a MED-HEP would improve other markers of cardiometabolic health and well-being (fasting blood pressure, fasting lipid profile, sleep quality, satiety, global metabolic alterations in the plasma metabolome, changes in the gut microbiota, subjective health and well-being), with no difference between groups. Collectively, the design of MEDGI-Carb allows several different research questions to be explored. TRIAL REGISTRATION: ClinicalTrials.gov identifier: NCT03410719

Bilberry Supplementation after Myocardial Infarction Decreases Microvesicles in Blood and Affects Endothelial Vesiculation

Scope: Diet rich in bilberries is considered cardioprotective, but the mechanisms of action are poorly understood. Cardiovascular disease is characterized by increased proatherogenic status and high levels of circulating microvesicles (MVs). In an open-label study patients with myocardial infarction receive an 8 week dietary supplementation with bilberry extract (BE). The effect of BE on patient MV levels and its influence on endothelial vesiculation in vitro is investigated. Methods and results: MVs are captured with acoustic trapping and platelet-derived MVs (PMVs), as well as endothelial-derived MVs (EMVs) are quantified with flow cytometry. The in vitro effect of BE on endothelial extracellular vesicle (EV) release is examined using endothelial cells and calcein staining. The mechanisms of BE influence on vesiculation pathways are studied by Western blot and qRT-PCR. Supplementation with BE decreased both PMVs and EMVs. Furthermore, BE reduced endothelial EV release, Akt phosphorylation, and vesiculation-related gene transcription. It also protects the cells from P2X7-induced EV release and increase in vesiculation-related gene expression. Conclusion: BE supplementation improves the MV profile in patient blood and reduces endothelial vesiculation through several molecular mechanisms related to the P2X7 receptor. The findings provide new insight into the cardioprotective effects of bilberries

Indolepropionic acid and novel lipid metabolites are associated with a lower risk of type 2 diabetes in the Finnish Diabetes Prevention Study

Wide-scale profiling technologies including metabolomics broaden the possibility of novel discoveries related to the pathogenesis of type 2 diabetes (T2D). By applying non-targeted metabolomics approach, we investigated here whether serum metabolite profile predicts T2D in a well-characterized study population with impaired glucose tolerance by examining two groups of individuals who took part in the Finnish Diabetes Prevention Study (DPS); those who either early developed T2D (n = 96) or did not convert to T2D within the 15-year follow-up (n = 104). Several novel metabolites were associated with lower likelihood of developing T2D, including indole and lipid related metabolites. Higher indolepropionic acid was associated with reduced likelihood of T2D in the DPS. Interestingly, in those who remained free of T2D, indolepropionic acid and various lipid species were associated with better insulin secretion and sensitivity, respectively. Furthermore, these metabolites were negatively correlated with low-grade inflammation. We replicated the association between indolepropionic acid and T2D risk in one Finnish and one Swedish population. We suggest that indolepropionic acid, a gut microbiota-produced metabolite, is a potential biomarker for the development of T2D that may mediate its protective effect by preservation of alpha-cell function. Novel lipid metabolites associated with T2D may exert their effects partly through enhancing insulin sensitivity.Peer reviewe