Impact of Dietary Polyphenols on Carbohydrate Metabolism

Polyphenols, including flavonoids, phenolic acids, proanthocyanidins and resveratrol, are a large and heterogeneous group of phytochemicals in plant-based foods, such as tea, coffee, wine, cocoa, cereal grains, soy, fruits and berries. Growing evidence indicates that various dietary polyphenols may influence carbohydrate metabolism at many levels. In animal models and a limited number of human studies carried out so far, polyphenols and foods or beverages rich in polyphenols have attenuated postprandial glycemic responses and fasting hyperglycemia, and improved acute insulin secretion and insulin sensitivity. The possible mechanisms include inhibition of carbohydrate digestion and glucose absorption in the intestine, stimulation of insulin secretion from the pancreatic β–cells, modulation of glucose release from the liver, activation of insulin receptors and glucose uptake in the insulin-sensitive tissues, and modulation of intracellular signalling pathways and gene expression. The positive effects of polyphenols on glucose homeostasis observed in a large number of in vitro and animal models are supported by epidemiological evidence on polyphenol-rich diets. To confirm the implications of polyphenol consumption for prevention of insulin resistance, metabolic syndrome and eventually type 2 diabetes, human trials with well-defined diets, controlled study designs and clinically relevant end-points together with holistic approaches e.g., systems biology profiling technologies are needed

Lipidome as a predictive tool in progression to type 2 diabetes in Finnish men

Background. There is a need for early markers to track and predict the development of type 2 diabetes mellitus (T2DM) from the state of normal glucose tolerance through prediabetes. In this study we tested whether the plasma molecular lipidome has biomarker potential to predicting the onset of T2DM. Methods. We applied global lipidomic profiling on plasma samples from well-phenotyped men (107 cases, 216 controls) participating in the longitudinal METSIM study at baseline and at five-year follow-up. To validate the lipid markers, an additional study with a representative sample of adult male population (n = 631) was also conducted. A total of 277 plasma lipids were analyzed using the lipidomics platform based on ultra performance liquid chromatography coupled to time-of-flight mass spectrometry. Lipids with the highest predictive power for the development of T2DM were computationally selected, validated and compared to standard risk models without lipids. Results. A persistent lipid signature with higher levels of triacylglycerols and diacyl-phospholipids as well as lowerlevels of alkylacyl phosphatidylcholines was observed in progressors to T2DM. Lysophosphatidylcholine acyl C18:2 (LysoPC(18:2)), phosphatidylcholines PC(32:1), PC(34:2e) and PC(36:1), and triacylglycerol TG(17:1/18:1/18:2) were selected to the full model that included metabolic risk factors and FINDRISC variables. When further adjusting for BM and age, these lipids had respective odds ratios of 0.32, 2.4, 0.50, 2.2 and 0.31 (all p 0; p <0.05). Notably, the lipid models remained predictive of the development of T2DM in the fasting plasma glucose-matched subset of the validation study. Conclusion. This study indicates that a lipid signature characteristic of T2DM is present years before the diagnosis and improves prediction of progression to T2DM. Molecular lipid biomarkers were shown to have predictive power also in a high-risk group, where standard risk factors are not helpful at distinguishing progressors from non-progressors. (C) 2017 The Authors. Published by Elsevier Inc.Peer reviewe

Lipidome as a predictive tool in progression to type 2 diabetes in Finnish men

Background. There is a need for early markers to track and predict the development of type 2 diabetes mellitus (T2DM) from the state of normal glucose tolerance through prediabetes. In this study we tested whether the plasma molecular lipidome has biomarker potential to predicting the onset of T2DM.Methods. We applied global lipidomic profiling on plasma samples from well-phenotyped men (107 cases, 216 controls) participating in the longitudinal METSIM study at baseline and at five-year follow-up. To validate the lipid markers, an additional study with a representative sample of adult male population (n = 631) was also conducted. A total of 277 plasma lipids were analyzed using the lipidomics platform based on ultra performance liquid chromatography coupled to time-of-flight mass spectrometry. Lipids with the highest predictive power for the development of T2DM were computationally selected, validated and compared to standard risk models without lipids.Results. A persistent lipid signature with higher levels of triacylglycerols and diacyl-phospholipids as well as lowerlevels of alkylacyl phosphatidylcholines was observed in progressors to T2DM. Lysophosphatidylcholine acyl C18:2 (LysoPC(18:2)), phosphatidylcholines PC(32:1), PC(34:2e) and PC(36:1), and triacylglycerol TG(17:1/18:1/18:2) were selected to the full model that included metabolic risk factors and FINDRISC variables. When further adjusting for BM and age, these lipids had respective odds ratios of 0.32, 2.4, 0.50, 2.2 and 0.31 (all p 0; p < 0.05). Notably, the lipid models remained predictive of the development of T2DM in the fasting plasma glucose-matched subset of the validation study.Conclusion. This study indicates that a lipid signature characteristic of T2DM is present years before the diagnosis and improves prediction of progression to T2DM. Molecular lipid biomarkers were shown to have predictive power also in a high-risk group, where standard risk factors are not helpful at distinguishing progressors from non-progressors

Postprandial differences in the plasma metabolome of healthy Finnish subjects after intake of a sourdough fermented endosperm rye bread versus white wheat bread

<p>Abstract</p> <p>Background</p> <p>The mechanism behind the lowered postprandial insulin demand observed after rye bread intake compared to wheat bread is unknown. The aim of this study was to use the metabolomics approach to identify potential metabolites related to amino acid metabolism involved in this mechanism.</p> <p>Methods</p> <p>A sourdough fermented endosperm rye bread (RB) and a standard white wheat bread (WB) as a reference were served in random order to 16 healthy subjects. Test bread portions contained 50 g available carbohydrate. <it>In vitro </it>hydrolysis of starch and protein were performed for both test breads. Blood samples for measuring glucose and insulin concentrations were drawn over 4 h and gastric emptying rate (GER) was measured. Changes in the plasma metabolome were investigated by applying a comprehensive two-dimensional gas chromatography coupled to time-of-flight mass spectrometry metabolomics platform (GC×GC-TOF-MS).</p> <p>Results</p> <p>Plasma insulin response to RB was lower than to WB at 30 min (P = 0.004), 45 min (P = 0.002) and 60 min (P < 0.001) after bread intake, and plasma glucose response was significantly higher at time point 90 min after RB than WB intake (P = 0.045). The starch hydrolysis rate was higher for RB than WB, contrary to the <it>in vitro </it>protein digestibility. There were no differences in GER between breads. From 255 metabolites identified by the metabolomics platform, 26 showed significant postprandial relative changes after 30 minutes of bread intake (p and q values < 0.05). Among them, there were changes in essential amino acids (phenylalanine, methionine, tyrosine and glutamic acid), metabolites involved in the tricarboxylic acid cycle (alpha-ketoglutaric, pyruvic acid and citric acid) and several organic acids. Interestingly, the levels of two compounds involved in the tryptophan metabolism (picolinic acid, ribitol) significantly changed depending on the different bread intake.</p> <p>Conclusions</p> <p>A single meal of a low fibre sourdough rye bread producing low postprandial insulin response brings in several changes in plasma amino acids and their metabolites and some of these might have properties beneficial for health.</p

Prolonged sleep restriction induces changes in pathways involved in cholesterol metabolism and inflammatory responses

Sleep loss and insufficient sleep are risk factors for cardiometabolic diseases, but data on how insufficient sleep contributes to these diseases are scarce. These questions were addressed using two approaches: an experimental, partial sleep restriction study (14 cases and 7 control subjects) with objective verification of sleep amount, and two independent epidemiological cohorts (altogether 2739 individuals) with questions of sleep insufficiency. In both approaches, blood transcriptome and serum metabolome were analysed. Sleep loss decreased the expression of genes encoding cholesterol transporters and increased expression in pathways involved in inflammatory responses in both paradigms. Metabolomic analyses revealed lower circulating large HDL in the population cohorts among subjects reporting insufficient sleep, while circulating LDL decreased in the experimental sleep restriction study. These findings suggest that prolonged sleep deprivation modifies inflammatory and cholesterol pathways at the level of gene expression and serum lipoproteins, inducing changes toward potentially higher risk for cardiometabolic diseases.Peer reviewe

Estudio del perfil de ácidos grasos en la evaluación de la Dieta Mediterránea como patrón de dieta saludable en poblaciones europeas

[spa] La composición lipídica del organismo humano refleja la formación endógena de lípidos así como la ingesta procedente de la dieta. Un exceso calórico no sólo de lípidos, sino también de los otros macronutrientes, puede conducir a un aumento de los factores de riesgo de enfermedad cardiovascular, que es en la actualidad la principal causa de mortalidad en las sociedades industrializadas. La creciente evidencia científica sugiere que ciertos patrones alimentarios pueden influir de forma favorable en los factores de riesgo cardiovascular. Uno de estos patrones de dieta saludable es la denominada "Dieta Mediterránea Tradicional", caracterizada por un consumo de aceite de oliva como fuente principal de lípidos. La incidencia durante los últimos años en las poblaciones europeas de la enfermedad cardiovascular y patologías relacionadas como la obesidad, sugiere una desviación de los "patrones alimentarios prudentes" a los denominados "patrones occidentales", caracterizados por elevadas ingesta de grasas, carne y cereales refinados. Este hecho plantea la necesidad de preservar y promover la dieta mediterránea tradicional en la población europea, sin excepción de los países mediterráneos que le han dado origen. Por ello, en esta tesis se evaluó el estado nutricional, así como el grado de cumplimiento de los actuales objetivos nutricionales nacionales y europeos, y del patrón alimentario mediterráneo en la población catalana actual. Como biomarcadores biológicos específicos del perfil lípidico, se estudió la composición de ácidos grasos plasmáticos, totales y de fosfolípidos de una muestra representativa de la población catalana. La técnica analítica utilizada fue la cromatografía de gases rápida, campo en el que se pusieron a punto tres novedosos métodos análiticos. Esta tesis permitió identificar los alimentos que contribuyen en mayor medida al porcentaje de energía procedente de los lípidos en la población catalana actual. El aceite destacó con un 7% de energía relativo a los lípidos totales, y el queso en cuanto a la grasa saturada, a diferencia de los productos lácteos, que eran los mayores contribuyentes de grasa saturada en la pasada década en esta población. La evaluación del índice de calidad de la dieta mediterránea mediante un enfoque metodológico a priori concluyó que un 64% de la población catalana se halla en el rango de cumplimiento de las características principales de la dieta mediterránea, presentando tan sólo un 5% de la población una baja adhesión a este patrón alimentario. En cuanto al grado de cumplimiento con los objetivos nutricionales, conviene destacar el elevado porcentaje de cumplimiento en relación a las frutas y verduras, superior al 75%, y el bajo porcentaje en cuanto a hidratos de carbono, inferior al 3% en cuanto a las recomendaciones europeas de aportar un 55% de la energía diaria. También se concluyó que las mujeres presentaban mayor grado de cumplimiento en relación a los ácidos grasos monoinsaturados y poliinsaturados, atribuible a su mayor consumo de aceite de oliva y de pescado respectivamente. Según los resultados obtenidos, la ingesta media de pescado en la población catalana es del orden de 80 g/dia, siendo tan sólo un 25% debido a pescado azul, que es el más rico en ácidos grasos poliinsaturados de cadena larga. La relación entre el contenido plasmático de EPA y DHA y los factores de riesgo cardiovascular clásicos mostró una relación inversa significativa entre el EPA y los niveles de colesterol total, trigliceridos e insulina, pero ninguna relación con los niveles de DHA. Paralelamente se estudió el efecto de un consumo moderado de aceite de oliva, principal componente de la dieta mediterránea, en individuos de cinco poblaciones europeas con diferentes hábitos alimentarios, concluyéndose que 25 ml/día de aceite de oliva pueden ser una herramienta útil para disminuir la presión sistólica en hombres europeos.[eng] The lipid composition of the human body reflects the endogenous lipid formation as well as the dietary lipid intake. An excess of energy, not only from lipids but also from the other macronutrients can lead to an increase in the cardiovascular disease risks.The increasing scientific evidence suggests that some dietary patterns can positively influence CVD risk factors. Among the healthy dietary patterns the Traditional Mediterranean Diet is highlighted. There is a need to maintain and promote this diet in the European population, without exception of the Mediterranean countries where it originated. This thesis focused on the evaluation of the nutritional status, compliance with the current European and national nutritional objectives, and adherence to the Mediterranean Diet by the current Catalan population. As specific biomarkers of the lipid profile, the fatty acid profile in total and phospholipids was evaluated in plasma. The analytic technique in use was fast gas chromatography, having developed three new analytic methods in this research field. The thesis allowed the identification of those foods which contribute most to the lipid profile in the current Catalan diet. Oil was the major contributor with 7% of relative energy from total lipids. Cheese is the food that contributes to the current Catalan diet with a higher percentage of saturated fat energy. The evaluation of the Mediterranean Quality Dietary Index in the representative Catalan sample suggested an appropriate adherence of the Catalan population to the Mediterranean dietary pattern. Furthermore, the current Catalan population follows most of the Spanish and European nutritional objectives. An increase of the carbohydrate intake should be recommended due to the fact that less than 3% accomplish the European nutritional objectives for this macronutrient. Nevertheless, a high compliance of fruit and vegetable intake was highlighted. According to our results, blue fish intake was estimated in only one portion per week, implying a future need to promote an increase in its consumption. In addition, the multicentric randomized cross-over study in 5 European populations, concluded that a moderate olive oil administration of 25 ml/day could be a useful tool to reduce the blood pressure in healthy men from European populations