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Objective: Fatty acid (FA) composition affects obesity-associated low-grade inflammation. It has been shown that the fatty acid desaturase (FADS) 2 gene polymorphism associates with FA metabolism and adipose tissue (AT) inflammation. This study aimed to investigate the relationship between FA metabolism and inflammation in different tissues and the possible interorgan cross talk., Methods: Cross-sectional baseline data from 155 individuals with obesity (both male and female) participating in the Roux-en-Y gastric bypass operation in the ongoing Kuopio Obesity Surgery Study were used. Gas chromatograph for FA composition, liver histology, and targeted RNA expression for gene expression profile were performed., Results: It was demonstrated that the saturated fatty acid (SFA) proportion in AT correlated positively with inflammation in subcutaneous AT (SAT) and visceral AT (VAT) but not in the liver, while the monounsaturated fatty acid (MUFA) proportion in SAT and VAT correlated negatively with AT inflammation. Notably, there was a positive correlation between AT n-6 polyunsaturated fatty acids (PUFAs), but not AT SFAs or MUFAs, and liver inflammation. This correlation was modified by the FADS2 genotype., Conclusions: The AT FA profile relates with AT inflammation. Additionally, there seems to be a complex interaction, partly regulated by the FADS2 genotype, regulating the interaction between FAs in AT and liver inflammation., (© 2017 The Obesity Society.)

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±9.5years (mean±SD), BMI 44.2±6.2kg/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., (Copyright © 2016 Elsevier Inc. All rights reserved.)

Scope: Limited information exists on how the relationship between dietary intake of fat and fatty acids in erythrocytes and plasma is modulated by polymorphisms in the FADS gene cluster. We examined gene-diet interaction of total marine PUFA intake with a known gene encoding Δ-5 desaturase enzyme (FADS1) variant (rs174550) for fatty acids in erythrocyte membranes and plasma phospholipids (PL), cholesteryl esters (CE), and triglycerides (TG)., Methods and Results: In this cross-sectional study, fatty acid compositions were measured using GC, and total intake of polyunsaturated fat from fish and fish oil was estimated using a food frequency questionnaire in a subsample (n = 962) of the Metabolic Syndrome in Men Study. We found nominally significant gene-diet interactions for eicosapentaenoic acid (EPA, 20:5n-3) in erythrocytes (pinteraction = 0.032) and for EPA in plasma PL (pinteraction = 0.062), CE (pinteraction = 0.035), and TG (pinteraction = 0.035), as well as for docosapentaenoic acid (22:5n-3) in PL (pinteraction = 0.007). After excluding omega-3 supplement users, we found a significant gene-diet interaction for EPA in erythrocytes (pinteraction < 0.003). In a separate cohort of the Kuopio Obesity Surgery Study, the same locus was strongly associated with hepatic mRNA expression of FADS1 (p = 1.5 × 10(-10) )., Conclusion: FADS1 variants may modulate the relationship between marine fatty acid intake and circulating levels of long-chain omega-3 fatty acids., (© 2015 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.)

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.

Plasma fatty acid (FA) composition is known to be an indicator of dietary fat quality, but the associations of other dietary factors with plasma FA composition remain unknown in children. We investigated the cross-sectional associations of food consumption with the proportions of FA and estimated desaturase activities in plasma cholesteryl esters (CE) and phospholipids (PL) among children. The subjects were a population sample of 423 children aged 6–8 years examined at baseline of The Physical Activity and Nutrition in Children (PANIC) Study. We assessed food consumption by food records and plasma FA composition by gas chromatography. We used linear regression models adjusted for age, sex, physical activity and total energy intake to analyze the associations. A higher consumption of vegetable oil-based margarine (fat 60–80 %) was associated with a higher proportion of linoleic and α-linolenic acids in plasma CE and PL. A higher consumption of high-fiber grain products was related to a lower proportion of oleic acid in CE and PL. The consumption of candy was directly associated with the proportion of palmitoleic and oleic acid in plasma CE. The consumption of vegetable oil-based margarine was inversely associated with estimated stearoyl-CoA-desaturase activity in plasma CE and PL and the consumption of candy was directly related to it in plasma CE. The results of our study suggest that plasma FA composition is not only a biomarker for dietary fat quality but also reflects the consumption of high-fiber grain products and foods high in sugar among children.

Background: The significance of erythrocyte membrane fatty acids (EMFAs) and their ratios to predict hyperglycemia and incident type 2 diabetes is unclear., Objective: We investigated EMFAs as predictors of the worsening of hyperglycemia and incident type 2 diabetes in a 5-y follow-up of a population-based study., Design: We measured EMFAs in 1346 Finnish men aged 45-73 y at baseline [mean ± SD age: 55 ± 6 y; body mass index (in kg/m(2)): 26.5 ± 3.5]. Our prospective follow-up study included only men who were nondiabetic at baseline and who had data available at the 5-y follow-up visit (n = 735)., Results: Our study showed that, after adjustment for confounding factors, palmitoleic acid (16:1n-7; P = 2.8 × 10(-7)), dihomo-γ-linolenic acid (20:3n-6; P = 2.3 × 10(-4)), the ratio of 16:1n-7 to 16:0 (P = 1.6 × 10(-8)) as a marker of stearoyl coenzyme A desaturase 1 activity, and the ratio of 20:3n-6 to 18:2n-6 (P = 9.4 × 10(-7)) as a marker of Δ(6)-desaturase activity significantly predicted the worsening of hyperglycemia (glucose area under the curve in an oral-glucose-tolerance test). In contrast, linoleic acid (18:2n-6; P = 0.0015) and the ratio of 18:1n-7 to 16:1n-7 (P = 1.5 × 10(-9)) as a marker of elongase activity had opposite associations. Statistical significance persisted even after adjustment for baseline insulin sensitivity, insulin secretion, and glycemia. Palmitoleic acid (P = 0.010) and the ratio of 16:1n-7 to 16:0 (P = 0.004) nominally predicted incident type 2 diabetes, whereas linoleic acid had an opposite association (P = 0.004), and n-3 polyunsaturated fatty acids did not show any associations., Conclusion: EMFAs and their ratios are associated longitudinally with changes in glycemia and the risk type 2 diabetes.

Background: Evidence on the effects of lifestyle interventions on plasma fatty acid composition in children is limited. Objective: We investigated the effects of a dietary and physical activity intervention on plasma fatty acid composition of cholesteryl esters (CEs) and phospholipids and estimated desaturase and elongase activities in children. Design: We conducted a 2-y controlled dietary and physical activity intervention based on Finnish nutrition and physical activity recommendations in a population sample of 506 children aged 6-8 y. We assessed plasma fatty acid composition by gas chromatography and estimated desaturase and elongase activities as the ratio of product fatty acids to precursor fatty acids. We analyzed data by using linear mixed models adjusted for age and sex. Results: The proportion of total polyunsaturated fatty acids (PUFAs) in CEs tended to increase in the intervention group compared with the control group (P = 0.007 for group × time interaction). The proportion of total PUFAs in phospholipids (P = 0.019 for group × time interaction) and the proportion of linoleic acid in CEs (P = 0.038 for group × time interaction) decreased in the control group. The proportion of a-linolenic acid in CEs (P < 0.001 for group × time interaction) increased and in phospholipids (P = 0.015 for group × time interaction) tended to increase in the intervention group. The proportion of stearic acid in CEs decreased in the intervention group (P = 0.001 for group × time interaction). The proportion of oleic acid in CEs (P = 0.002 for group × time interaction) increased and in phospholipids (P = 0.023 for group × time interaction) tended to increase in the control group. Estimated elongase activity in CEs decreased in the control group (P = 0.050 for group × time interaction). Intervention had no effect on estimated desaturase activities. Conclusions: Dietary and physical activity intervention had a beneficial effect on plasma fatty acid composition in children by preventing the decrease in the proportion of total PUFAs and linoleic acid and by increasing the proportion of α-linolenic acid. [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]

Dietary adherence to four different fat-modified diets was examined in 160 subjects by determining the fatty acid composition of serum cholesterol esters (CEs) and erythrocyte (ER) and platelet (PT) membranes in addition to food records. Subjects were randomly assigned to one of the following diet groups: 1) high-sat-35/14:10:4 (% of energy from total/ saturated:monounsaturated:polyunsaturated fatty acids in the actual diet) 2) AHA (American Heart Association) type-32/ 10:8:8 3) monoene-enriched-34/11:11:5, or 4) low-fat-30/ 12:8:3 for 6 mo. Decreases in the proportions of palmitic acid in CEs were found in the AHA-type and monoene-enriched-diet groups. An increased proportion of linoleic acid in CEs was found in the AHA-type group. The differences in the proportions of palmitic acid in CEs and linoleic and palmitoleic acids in PTs were significant in the AHA-type and monoene-enriched-diet groups compared with the high-sat group. An increase in α-linolenic acid in CEs was an indicator of the use of low erucic acid rapeseed oil, which was the main source of monoenes in the monoene-enriched-diet group. [ABSTRACT FROM AUTHOR]

This study describes the evolution of tissue composition and serum metabolites of common dentex (Dentex dentex) in different maturity stages. During maturation, diet and perivisceral fat provide the materials needed for the development of gonads. Female and male fish had higher total proteins, total fat, triglycerides (TG) and cholesterol in their serum, at spawning and spermiation, respectively. The examination of dentex tissues (muscle, liver and gonad) revealed no statistically significant differences (P<0.05) in energy density and lipid content during different maturity stages and there was no conclusive evidence that energy density and lipid content differ between sexes. In muscle, liver and gonad triglycerides fraction, the proportion of saturated fatty acids (FA) was greater than the proportion of polyunsaturated fatty acids (PUFA), whereas the reverse observation was made (with the exception of liver) in the polar lipid (PL) fraction of the above tissues. In muscle and liver, the main polyunsaturated fatty acids (n-3 PUFA) were docosahexaenoic (DHA, 22:6n-3) and eicosapentaenoic (EPA, 20:5n-3) acids. The main n-6 polyunsaturated fatty acids were linoleic (18:2n-6) and arachidonic (20:4n-6) acids. Palmitic (16:0) and oleic (18:1n-9) acids were the main saturated fatty acids and monoenes, respectively. The relative concentration of the major fatty acids varied seasonally and a pattern can be seen in both mature and immature dentex. In the PL fraction of muscle, higher values of total saturated and n-3 fatty acids, palmitic acid and DHA were obtained during summer in comparison to winter samplings; this trend was also shown by the total saturated fatty acids in the TG fraction. [Copyright &y& Elsevier]