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Background: Knowledge on the association of plasma fatty acid (FA) composition in triacylglycerol (TG) and phospholipid (PL) fractions with cardiometabolic risk in population-based samples of children is lacking., Objective: We investigated the associations of proportions of FA in plasma TG and PL fractions as well as estimated desaturase and elongase activities with cardiometabolic risk in a population sample of 384 children aged 6-8 years., Methods: Plasma FA composition was analyzed by gas chromatography. Desaturase and elongase activities were estimated as product-to-precursor FA ratios. Cardiometabolic risk was assessed using a continuous cardiometabolic risk score (CRS) variable., Results: Higher proportions of myristic and palmitoleic acids in plasma TG and PL were associated with a higher CRS. A lower proportion of linoleic acid in plasma TG was related to a higher CRS. Estimated stearoyl-CoA-desaturase and Δ6-desaturase activities in plasma TG and PL were directly associated with CRS, whereas estimated elongase activity in plasma TG and PL was inversely related to CRS., Conclusions: Greater proportions of myristic and palmitoleic acids and a smaller proportion of linoleic acid in plasma, as well as higher estimated stearoyl-CoA-desaturase and Δ6-desaturase activities and a lower estimated elongase activity, are associated with cardiometabolic risk factors among children. These findings reinforce the evidence that FA metabolism is closely associated with cardiometabolic risk, starting already from childhood., (Copyright © 2016 National Lipid Association. Published by Elsevier Inc. All rights reserved.)

Aims/hypothesis: Our aim was to investigate the fasting proportions of fatty acids and estimated desaturase and elongase activities in three different lipid fractions in plasma, phospholipids (PLs), cholesteryl esters (CEs) and triacylglycerols (TGs), as predictors for the worsening of glycaemia (area under the glucose curve in an OGTT [glucose AUC]) and incident type 2 diabetes in a 5.9 year follow-up of the Metabolic Syndrome in Men population-based cohort., Methods: Fatty acid proportions were measured in plasma PL, CE and TG fractions in 1,364 Finnish men aged 45-68 years at baseline. The prospective follow-up study included only men who were non-diabetic at baseline and had data available at follow-up (n = 1,302). A total of 71 participants developed new type 2 diabetes during follow-up., Results: After adjusting for confounding factors, total saturated fatty acids, palmitoleic acid (16:1n-7), dihomo-γ-linolenic acid (20:3n-6) and estimated stearoyl-CoA desaturase 1 and Δ(6)-desaturase (D6D) enzyme activities significantly predicted the worsening of glycaemia whereas total polyunsaturated fatty acid, linoleic acid (18:2n-6) and elongase activity predicted a decrease in the glucose AUC. Estimated D6D activity and dihomo-γ-linolenic acid (20:3n-6) were associated with an increased risk of incident type 2 diabetes. Results were consistent across the three different lipid fractions. However, fatty acid proportions in the PL and CE fractions were stronger predictors for glycaemia and incident type 2 diabetes compared with fatty acid proportions in the TG fraction., Conclusions/interpretation: Selected fatty acid proportions of plasma lipid fractions and their ratios, which reflect desaturase and elongase enzyme activities, may be good biomarkers for the worsening of glycaemia and incident type 2 diabetes.

Purpose: Fatty acid desaturase (FADS) variants associate with fatty acid (FA) and adipose tissue (AT) metabolism and inflammation. Thus, the role of FADS1 variants in the regulation of dietary linoleic acid (LA)-induced effects on AT inflammation was investigated. Methods: Subjects homozygotes for the TT and CC genotypes of the FADS1-rs174550 (TT, n = 25 and CC, n = 28) or -rs174547 (TT, n = 42 and CC, n = 28), were either recruited from the METabolic Syndrome In Men cohort to participate in an intervention with LA-enriched diet (FADSDIET) or from the Kuopio Obesity Surgery (KOBS) study. GC and LC–MS for plasma FA proportions and eicosanoid concentrations and AT gene expression for AT inflammatory score (AT-InSc) was determined. Results: We observed a diet-genotype interaction between LA-enriched diet and AT-InSc in the FADSDIET. In the KOBS study, interleukin (IL)1 beta mRNA expression in AT was increased in subjects with the TT genotype and highest LA proportion. In the FADSDIET, n-6/LA proportions correlated positively with AT-InSc in those with the TT genotype but not with the CC genotype after LA-enriched diet. Specifically, LA- and AA-derived pro-inflammatory eicosanoids related to CYP450/sEH-pathways correlated positively with AT-InSc in those with the TT genotype, whereas in those with the CC genotype, the negative correlations between pro-inflammatory eicosanoids and AT-InSc related to COX/LOX-pathways. Conclusions: LA-enriched diet increases inflammatory AT gene expression in subjects with the TT genotype, while CC genotype could play a protective role against LA-induced AT inflammation. Overall, the FADS1 variant could modify the dietary LA-induced effects on AT inflammation through the differential biosynthesis of AA-derived eicosanoids. [ABSTRACT FROM AUTHOR]

Background Non-alcoholic steatohepatitis (NASH) is associated with changes in fatty acid (FA) metabolism. However, specific changes in metabolism and hepatic mRNA expression related to NASH independent of simple steatosis, obesity and diet are unknown. Methods Liver histology, serum and liver FA composition and estimated enzyme activities based on the FA ratios in cholesteryl esters and triglycerides were assessed in 92 obese participants of the Kuopio Obesity Surgery Study (KOBS) divided to those with normal liver, steatosis or NASH (30 men and 62 women, age 46.8 ± 9.5 years (mean ± SD), BMI 44.2 ± 6.2 kg/m 2 ). Plasma FA composition was also investigated in the Metabolic Syndrome in Men (METSIM) Study (n = 769), in which serum alanine aminotransferase (ALT) was used as a marker of liver disease. Results Obese individuals with NASH had higher activity of estimated activities of delta-6 desaturase (D6D, p < 0.002) and stearoyl-CoA desaturase 1 (SCD1, p < 0.002) and lower activity of delta-5 desaturase (D5D, p < 0.002) when compared to individuals with normal liver. Estimated activities of D5D, D6D and SCD1 correlated positively between liver and serum indicating that serum estimates reflected liver metabolism. Accordingly, NASH was associated with higher hepatic mRNA expression of corresponding genes FADS1 , FADS2 and SCD . Finally, differences in FA metabolism that associated with NASH in obese individuals were also associated with high ALT in the METSIM Study. Conclusions We demonstrated alterations in FA metabolism and endogenous desaturase activities that associate with NASH, independent of obesity and diet. This suggests that changes in endogenous FA metabolism are related to NASH and that they may contribute to the progression of the disease. [ABSTRACT FROM AUTHOR]

Background: The effect of weight loss on different plasma lipid subclasses at the molecular level is unknown. The aim of this study was to examine whether a diet-induced weight reduction result in changes in the extended plasma lipid profiles (lipidome) in subjects with features of metabolic syndrome in a 33-week intervention. Methodology/Principal Findings: Plasma samples of 9 subjects in the weight reduction group and 10 subjects in the control group were analyzed using mass spectrometry based lipidomic and fatty acid analyses. Body weight decreased in the weight reduction group by 7.8±2.9% (p,0.01). Most of the serum triacylglycerols and phosphatidylcholines were reduced. The decrease in triacylglycerols affected predominantly the saturated short chain fatty acids. This decrease of saturated short chain fatty acid containing triacylglycerols correlated with the increase of insulin sensitivity. However, levels of several longer chain fatty acids, including arachidonic and docosahexanoic acid, were not affected by weight loss. Levels of other lipids known to be associated with obesity such as sphingolipids and lysophosphatidylcholines were not altered by weight reduction. Conclusions/Significance: Diet-induced weight loss caused significant changes in global lipid profiles in subjects with abnormal glucose metabolism. The observed changes may affect insulin sensitivity and glucose metabolism in these subjects. [ABSTRACT FROM AUTHOR]

Background: Carbohydrate modification based on rye bread and pasta enhances early insulin secretion in subjects with the metabolic syndrome. Objective: Because the actions of insulin and cholesterol metabolism are interrelated, the question is raised of whether it is possible to alter cholesterol metabolism by means of dietary carbohydrate modification. Design: We investigated the 12-wk effects of dietary carbohydrate modification on cholesterol synthesis and absorption by measuring the ratios of surrogate markers of precursor (cholestenol, desmosterol, and lathosterol) and absorption (cholestanol and plant sterols) sterols to cholesterol and their association to glucose metabolism in 74 subjects with the metabolic syndrome. The subjects were randomly assigned to diets with rye bread and pasta (RPa) or oat, wheat bread, and potato(OWPo)as the main carbohydrate source (34% and 37% of energy intake, respectively). Results: During the study, serum cholesterol concentrations remained unchanged. Cholesterol synthesis was lower (6-10% for cholestenol and lathosterol; P < 0.05) and absorption higher (9%; P<0.05 for sitosterol) with the OWPo diet than at baseline. With the RPa diet, cholesterol absorption was lower and synthesis higher than with the OWPo diet. The increment in the glucose area under the curve with the RPa diet was positively related to baseline cholesterol synthesis (eg, lathosterol; r = 0.480, P < 0.05) and negatively to absorption (for cholestanol; r=-0.520, P<0.05). In the combined group, the changes in the cholestanol ratio and the insulinogenic index were interrelated (r=-0.464, P < 0.001). Conclusions: Carbohydrate modifications had dissimilar effects on cholesterol metabolism. Consumption of RPa, as compared with OWPo, may be clinically more favorable because it seems to inhibit the absorption of cholesterol, a factor crucial in the development of arterial atherosclerosis. [ABSTRACT FROM AUTHOR]