| 1. |
- Bjermo, Helena, et al.
(författare)
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Effects of n-6 PUFAs compared with SFAs on liver fat, lipoproteins, and inflammation in abdominal obesity : a randomized controlled trial
- 2012
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Ingår i: American Journal of Clinical Nutrition. - : Elsevier BV. - 0002-9165 .- 1938-3207. ; 95:5, s. 1003-1012
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Tidskriftsartikel (refereegranskat)abstract
- BACKGROUND: Replacing SFAs with vegetable PUFAs has cardiometabolic benefits, but the effects on liver fat are unknown. Increased dietary n-6 PUFAs have, however, also been proposed to promote inflammation-a yet unproven theory. OBJECTIVE: We investigated the effects of PUFAs on liver fat, systemic inflammation, and metabolic disorders. DESIGN: We randomly assigned 67 abdominally obese subjects (15% had type 2 diabetes) to a 10-wk isocaloric diet high in vegetable n-6 PUFA (PUFA diet) or SFA mainly from butter (SFA diet), without altering the macronutrient intake. Liver fat was assessed by MRI and magnetic resonance proton (1H) spectroscopy (MRS). Proprotein convertase subtilisin/kexin type-9 (PCSK9, a hepatic LDL-receptor regulator), inflammation, and adipose tissue expression of inflammatory and lipogenic genes were determined. RESULTS: A total of 61 subjects completed the study. Body weight modestly increased but was not different between groups. Liver fat was lower during the PUFA diet than during the SFA diet [between-group difference in relative change from baseline; 16% (MRI; P < 0.001), 34% (MRS; P = 0.02)]. PCSK9 (P = 0.001), TNF receptor-2 (P < 0.01), and IL-1 receptor antagonist (P = 0.02) concentrations were lower during the PUFA diet, whereas insulin (P = 0.06) tended to be higher during the SFA diet. In compliant subjects (defined as change in serum linoleic acid), insulin, total/HDL-cholesterol ratio, LDL cholesterol, and triglycerides were lower during the PUFA diet than during the SFA diet (P < 0.05). Adipose tissue gene expression was unchanged. CONCLUSIONS: Compared with SFA intake, n-6 PUFAs reduce liver fat and modestly improve metabolic status, without weight loss. A high n-6 PUFA intake does not cause any signs of inflammation or oxidative stress. Downregulation of PCSK9 could be a novel mechanism behind the cholesterol-lowering effects of PUFAs.
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| 2. |
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| 3. |
- Iggman, David, et al.
(författare)
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Adipose tissue fatty acids and insulin sensitivity in elderly men.
- 2010
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Ingår i: Diabetologia. - : Springer Science and Business Media LLC. - 0012-186X .- 1432-0428. ; 53:5, s. 850-857
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Tidskriftsartikel (refereegranskat)abstract
- AIMS/HYPOTHESIS Dietary fatty acids may affect insulin sensitivity. Adipose tissue fatty acid composition partly reflects long-term dietary intake, but data from large studies regarding relationships with insulin sensitivity are lacking. We aimed to determine the association between adipose tissue fatty acids and insulin sensitivity in elderly Swedish men. METHODS In a cross-sectional analysis of the community-based Uppsala Longitudinal Study of Adult Men (n = 795, mean age 71 years), adipose tissue biopsies were obtained and fatty acid composition was determined by gas-liquid chromatography. Insulin sensitivity was measured directly by a euglycaemic clamp. RESULTS Palmitic acid (16:0), the major saturated fatty acid (SFA) in the diet and in adipose tissue, was negatively correlated with insulin sensitivity (r = -0.14), as were 16:1 n-7 (r = -0.15), 20:3 n-6 (r = -0.31), 20:4 n-6 (r = -0.38), 22:4 n-6 (r = -0.37) and 22:5 n-3 (r = -0.24; p < 0.001 for all). Some minor SFAs were positively correlated; 12:0 (r = 0.46), 14:0 (r = 0.32), 17:0 (r = 0.21) and 18:0 (r = 0.41; p < 0.001 for all), as were essential polyunsaturated fatty acids (PUFAs) 18:2 n-6 (r = 0.10, p < 0.01) and 18:3 n-3 (r = 0.16, p < 0.001). Docosahexaenoic acid (22:6 n-3) was negatively correlated (r = -0.11, p < 0.01), whereas eicosapentaenoic acid (20:5 n-3) was not (r = -0.02, NS). Most associations diminished or disappeared in lean individuals, indicating an effect of obesity. CONCLUSIONS/INTERPRETATION Adipose tissue enriched with palmitic acid and depleted of essential PUFAs is associated with insulin resistance. The positive association between minor SFAs and insulin sensitivity merits further investigation.
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| 4. |
- Iggman, David, et al.
(författare)
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Replacing dairy fat with rapeseed oil causes rapid improvement of hyperlipidaemia : a randomized controlled study
- 2011
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Ingår i: Journal of Internal Medicine. - : Wiley. - 0954-6820 .- 1365-2796. ; 270:4, s. 356-364
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Tidskriftsartikel (refereegranskat)abstract
- Background. Rapeseed oil (RO), also known as canola oil, principally contains the unsaturated fatty acids 18:1n-9, 18:2n-6 and 18:3n-3 and may promote cardiometabolic health. Objective. To investigate the effects on lipoprotein profile, factors of coagulation and insulin sensitivity of replacing a diet rich in saturated fat from dairy foods (DF diet) with a diet including RO-based fat (RO diet). Design. During a 2 x 3-week randomized, controlled, cross-over trial, 20 free-living hyperlipidaemic subjects were provided with isocaloric test diets that differed in fat composition alone. Blood lipoprotein profile, coagulation and fibrinolytic factors and insulin sensitivity (euglycaemic clamp) were determined before and after the dietary intervention. Results. All subjects completed the study, and compliance was high according to changes in serum fatty acids. The RO diet, but not the DF diet, reduced the levels of serum cholesterol (-17%), triglycerides (-20%) and low-density lipoprotein cholesterol (-17%), cholesterol/high-density lipoprotein (HDL) cholesterol ratio (-21%), apolipoprotein (apo) B/apo A-I ratio (-4%) and factor VII coagulant activity (FVIIc) (-5%) from baseline. These changes were significantly different between the diets (P = 0.05 to P < 0.0001), except for FVIIc (P = 0.1). The RO diet, but not the DF diet, modestly increased serum lipoprotein( a) (+6%) and tended to increase the glucose disappearance rate (K-value, +33%). HDL cholesterol, insulin sensitivity, fibrinogen and tissue plasminogen activator inhibitor-1 levels did not change from baseline or differ between the two diets. Conclusions. In a diet moderately high in total fat, replacing dairy fat with RO causes a rapid and clinically relevant improvement in serum lipoprotein profile including lowering of triglycerides in hyperlipidaemic individuals.
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| 5. |
- Iggman, David, et al.
(författare)
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Role of dietary fats in modulating cardiometabolic risk during moderate weight gain : a randomized double-blind overfeeding trial (LIPOGAIN study)
- 2014
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Ingår i: Journal of the American Heart Association. - 2047-9980 .- 2047-9980. ; 3:5
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Tidskriftsartikel (refereegranskat)abstract
- BACKGROUND: Whether the type of dietary fat could alter cardiometabolic responses to a hypercaloric diet is unknown. In addition, subclinical cardiometabolic consequences of moderate weight gain require further study.METHODS AND RESULTS: In a 7-week, double-blind, parallel-group, randomized controlled trial, 39 healthy, lean individuals (mean age of 27±4) consumed muffins (51% of energy [%E] from fat and 44%E refined carbohydrates) providing 750 kcal/day added to their habitual diets. All muffins had identical contents, except for type of fat; sunflower oil rich in polyunsaturated fatty acids (PUFA diet) or palm oil rich in saturated fatty acids (SFA diet). Despite comparable weight gain in the 2 groups, total: high-density lipoprotein (HDL) cholesterol, low-density lipoprotein:HDL cholesterol, and apolipoprotein B:AI ratios decreased during the PUFA versus the SFA diet (-0.37±0.59 versus +0.07±0.29, -0.31±0.49 versus +0.05±0.28, and -0.07±0.11 versus +0.01±0.07, P=0.003, P=0.007, and P=0.01 for between-group differences), whereas no significant differences were observed for other cardiometabolic risk markers. In the whole group (ie, independently of fat type), body weight increased (+2.2%, P<0.001) together with increased plasma proinsulin (+21%, P=0.007), insulin (+17%, P=0.003), proprotein convertase subtilisin/kexin type 9, (+9%, P=0.008) fibroblast growth factor-21 (+31%, P=0.04), endothelial markers vascular cell adhesion molecule-1, intercellular adhesion molecule-1, and E-selectin (+9, +5, and +10%, respectively, P<0.01 for all), whereas nonesterified fatty acids decreased (-28%, P=0.001).CONCLUSIONS: Excess energy from PUFA versus SFA reduces atherogenic lipoproteins. Modest weight gain in young individuals induces hyperproinsulinemia and increases biomarkers of endothelial dysfunction, effects that may be partly outweighed by the lipid-lowering effects of PUFA.CLINICAL TRIAL REGISTRATION URL: http://ClinicalTrials.gov. Unique identifier: NCT01427140.
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| 6. |
- Iggman, David, et al.
(författare)
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Role of different dietary saturated fatty acids for cardiometabolic risk
- 2011
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Ingår i: Journal of Clinical Lipidology. - 1933-2874 .- 1876-4789. ; 6:2, s. 209-223
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Forskningsöversikt (refereegranskat)abstract
- There is clinical and observational evidence to suggest that saturated fatty acids (SFA) increase cardiovascular disease risk compared with polyunsaturated fatty acids from vegetable oils. Replacing SFA intake has thus been a public health target, but the role of individual SFA in metabolic disease is still incompletely understood. Observational data Indicate that all SFA may not necessarily be detrimental. The cholesterol-raising effect of SFA differs among individual SFA and possibly also with regard to cardiovascular and metabolic risk factors. The impact of dietary SFA on cardiovascular disease remains somewhat controversial, possibly due to such individual differences. In this article, we will also separately discuss the effects of dairy SFA, including biomarkers, as a means to elucidate these relationships between fatty acids, foodstuffs and cardiometabolic disease.
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| 7. |
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| 8. |
- Jobs, Elisabeth, et al.
(författare)
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Serum cathepsin S is associated with decreased insulin sensitivity and the development of diabetes type 2 in a community-based cohort of elderly men
- 2012
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Ingår i: Diabetes Care. - : American diabetes association. - 0149-5992 .- 1935-5548. ; 36:1, s. 163-165
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Tidskriftsartikel (refereegranskat)abstract
- OBJECTIVE. To investigate associations between serum cathepsin S, impaired insulin sensitivity, defective insulin secretion, and diabetes risk in a community-based sample of elderly men without diabetes.RESEARCH DESIGN AND METHODS. Serum cathepsin S, insulin sensitivity (euglycaemic-hyperinsulinaemic clamp), and insulin secretion (early insulin response during an oral glucose tolerance test) were measured in 905 participants of the Uppsala Longitudinal Study of Adult Men (mean age, 71 years). Thirty participants developed diabetes during 6 years of follow-up.RESULTS. After adjustment for age, anthropometric variables, and inflammatory markers, higher cathepsin S was associated with decreased insulin sensitivity (regression coefficient per SD increase -0.09 [95% CI -0.14 to -0.04], P = 0.001), but no association with early insulin response was found. Moreover, higher cathepsin S was associated with a higher risk for developing diabetes (odds ratio per SD increase 1.48 [1.08-2.01], P = 0.01).CONCLUSIONS. Cathepsin S activity appears to be involved in the early dysregulation of glucose and insulin metabolism.
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| 9. |
- Magnusdottir, O. K., et al.
(författare)
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Plasma alkylresorcinols C17:0/C21:0 ratio, a biomarker of relative whole-grain rye intake, is associated to insulin sensitivity : a randomized study
- 2014
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Ingår i: European Journal of Clinical Nutrition. - : Springer Science and Business Media LLC. - 0954-3007 .- 1476-5640. ; 68:4, s. 453-458
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Tidskriftsartikel (refereegranskat)abstract
- BACKGROUND/OBJECTIVES: Few studies have used biomarkers of whole-grain intake to study its relation to glucose metabolism. We aimed to investigate the association between plasma alkylresorcinols (AR), a biomarker of whole-grain rye and wheat intake, and glucose metabolism in individuals with metabolic syndrome (MetS). SUBJECTS/METHODS: Participants were 30-65 years of age, with body mass index 27-40 kg/m(2) and had MetS without diabetes. Individuals were recruited through six centers in the Nordic countries and randomized to a healthy Nordic diet (ND, n=96), rich in whole-grain rye and wheat, or a control diet (n=70), for 18-24 weeks. In addition, associations between total plasma AR concentration and C17:0/C21:0 homolog ratio as an indication of the relative whole-grain rye intake, and glucose metabolism measures from oral glucose tolerance tests were investigated in pooled (ND + control) regression analyses at 18/24 weeks. RESULTS: ND did not improve glucose metabolism compared with control diet, but the AR C17:0/C21:0 ratio was inversely associated with fasting insulin concentrations (P=0.002) and positively associated with the insulin sensitivity indices Matsuda ISI (P=0.026) and disposition index (P=0.022) in pooled analyses at 18/24 weeks, even after adjustment for confounders. The AR C17:0/C21:0 ratio was not significantly associated with insulin secretion indices. Total plasma AR concentration was not related to fasting plasma glucose or fasting insulin at 18/24 weeks. CONCLUSIONS: The AR C17:0/C21:0 ratio, an indicator of relative whole-grain rye intake, is associated with increased insulin sensitivity in a population with MetS.
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| 10. |
- Rosqvist, Fredrik, et al.
(författare)
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Overfeeding Polyunsaturated and Saturated Fat Causes Distinct Effects on Liver and Visceral Fat Accumulation in Humans
- 2014
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Ingår i: Diabetes. - : American Diabetes Association. - 0012-1797 .- 1939-327X. ; 63:7, s. 2356-2368
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Tidskriftsartikel (refereegranskat)abstract
- Excess ectopic fat storage is linked to type 2 diabetes. The importance of dietary fat composition for ectopic fat storage in humans is unknown. We investigated liver fat accumulation and body composition during overfeeding saturated (SFA) or polyunsaturated (PUFA) fat. LIPOGAIN was a double-blind, parallel-group, randomized trial. Thirty-nine young and normal-weight individuals were overfed muffins high in SFA (palm oil) or n-6 PUFA (sunflower oil) for 7 weeks. Liver fat, visceral (VAT), subcutaneous abdominal (SAT), and total adipose tissue (TAT), pancreatic fat, and lean tissue was assessed by MRI. Transcriptomics were performed in SAT. Both groups gained similar weight. SFA however markedly increased liver fat compared with PUFA and caused 2-fold larger increase in VAT than PUFA. Conversely, PUFA caused a nearly 3-fold larger increase in lean tissue than SFA. Increase in liver fat directly correlated with changes in plasma SFA and inversely with PUFA. Genes involved in regulating energy dissipation, insulin resistance, body composition and fat cell differentiation in SAT were differentially regulated between diets, and associated with increased PUFA in SAT. In conclusion, overeating SFA promotes hepatic and visceral fat storage whereas excess energy from PUFA may instead promote lean tissue in healthy humans.
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