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- 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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| 2. |
- 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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