| 1. |
- Burén, Jonas, et al.
(författare)
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In vitro reversal of hyperglycemia normalizes insulin action in fat cells from type 2 diabetes patients : is cellular insulin resistance caused by glucotoxicity in vivo?
- 2003
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Ingår i: Metabolism. - : Elsevier BV. - 0026-0495 .- 1532-8600. ; 52:2, s. 239-45
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Tidskriftsartikel (refereegranskat)abstract
- Chronic hyperglycemia promotes the development of insulin resistance. The aim of this study was to investigate whether cellular insulin resistance is secondary to the diabetic state in human type 2 diabetes. Subcutaneous fat biopsies were taken from 3 age-, sex-, and body mass index (BMI)-matched groups with 10 subjects in each group: type 2 diabetes patients with either good (hemoglobin A(1c) [HbA(1c)] < 7%, G) or poor (HbA(1c) > 7.5%, P) metabolic control and healthy control subjects (C). Insulin action in vitro was studied by measurements of glucose uptake both directly after cell isolation and following a 24-hour incubation at a physiological glucose level (6 mmol/L). The relationship with insulin action in vivo was addressed by employing the euglycemic clamp technique. Freshly isolated fat cells from type 2 diabetes patients with poor metabolic control had approximately 55% lower maximal insulin response (1,000 microU/mL) on glucose uptake (P <.05) compared to C. Cells from P were more insulin-resistant (P <.05) than cells from G at a low (5 microU/mL) but not at a high (1,000 microU/mL) insulin concentration, suggesting insulin insensitivity. However, following 24 hours of incubation at physiological glucose levels, insulin resistance was completely reversed in the diabetes cells and no differences in insulin-stimulated glucose uptake were found among the 3 groups. Insulin sensitivity in vivo assessed with hyperinsulinemic, euglycemic clamp (M-value) was significantly associated with insulin action on glucose uptake in fresh adipocytes in vitro (r = 0.50, P <.01). Fasting blood glucose at the time of biopsy and HbA(1c), but not serum insulin, were negatively correlated to insulin's effect to stimulate glucose uptake in vitro (r = -0.36, P =.064 and r = - 0.41, P <.05, respectively) in all groups taken together. In the in vivo situation, fasting blood glucose, HbA(1c), and serum insulin were all negatively correlated to insulin sensitivity (M-value; r = -0.62, P<.001, r= -0.61, P<.001, and r = -0.56, p <.01, respectively). Cell size, waist-to-hip ration (WHR), and BMI correlated negatively with insulin's effect to stimulate glucose uptake both in vitro (r = -0.55, P <.01, r = -0.54, P <.01, and r = -0.43, P <.05, respectively) and in vivo (r = -0.43, P <.05, r = -0.50, P <.01, and r = -0.36, P <.05, respectively). Multiple regression analyses revealed that adipocyte cell size and WHR independently predicted insulin resistance in vitro. Furthermore, insulin sensitivity in vivo could be predicted by fasting blood glucose and serum insulin levels. We conclude that insulin resistance in fat cells from type 2 diabetes patients is fully reversible following incubation at physiological glucose concentrations. Thus, cellular insulin resistance may be mainly secondary to the hyperglycemic state in vivo.
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| 2. |
- Chorell, Elin, et al.
(författare)
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Pregnancy to postpartum transition of serum metabolites in women with gestational diabetes
- 2017
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Ingår i: Metabolism-Clinical and Experimental. - : Elsevier BV. - 0026-0495 .- 1532-8600. ; 72, s. 27-36
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Tidskriftsartikel (refereegranskat)abstract
- Context. Gestational diabetes is commonly linked to development of type 2 diabetes mellitus (T2DM). There is a need to characterize metabolic changes associated with gestational diabetes in order to find novel biomarkers for T2DM. Objective. To find potential pathophysiological mechanisms and markers for progression from gestational diabetes mellitus to T2DM by studying the metabolic transition from pregnancy to postpartum. Design. The metabolic transition profile from pregnancy to postpartum was characterized in 56 women by mass spectrometry-based metabolomics; 11 women had gestational diabetes mellitus, 24 had normal glucose tolerance, and 21 were normoglycaemic but at increased risk for gestational diabetes mellitus. Fasting serum samples collected during trimester 3 (gestational week 32 +/- 0.6) and postpartum (10.5 +/- 0.4 months) were compared in diagnosis-specific multivariate models (orthogonal partial least squares analysis). Clinical measurements (e.g., insulin, glucose, lipid levels) were compared and models of insulin sensitivity and resistance were calculated for the same time period. Results. Women with gestational diabetes had significantly increased postpartum levels of the branched-chain amino acids (BCAAs) leucine, isoleucine, and valine, and their circulating lipids did not return to normal levels after pregnancy. The increase in BCAAs occurred postpartum since the BCAAs did not differ during pregnancy, as compared to normoglycemic women. Conclusions. Postpartum levels of specific BCAAs, notably valine, are related to gestational diabetes during pregnancy. (C) 2017 Elsevier Inc. All rights reserved.
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| 3. |
- Goedecke, Julia H, et al.
(författare)
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Ethnic differences in serum lipoproteins and their determinants in South African women
- 2010
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Ingår i: Metabolism. - : Elsevier BV. - 0026-0495 .- 1532-8600. ; 59:9, s. 1341-1350
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Tidskriftsartikel (refereegranskat)abstract
- The objective of the study was to characterize ethnic differences in lipid levels and low-density lipoprotein (LDL) particle size and subclasses in black and white South African women and to explore the associations with insulin sensitivity (S(I)), body composition, and lifestyle factors. Fasting serum lipids and LDL size and subclasses, body composition (dual-energy x-ray absorptiometry), and S(I) (frequently sampled intravenous glucose tolerance test) were measured in normal-weight (body mass index <25 kg/m(2)) black (n = 15) and white (n = 15), and obese (body mass index >30 kg/m(2)) black (n = 13) and white (n = 13) women. Normal-weight and obese black women had lower triglycerides (0.59 +/- 0.09 and 0.77 +/- 0.10 vs 0.89 +/- 0.09 and 0.93 +/- 0.10 mmol/L, P < .05) and high-density lipoprotein cholesterol (1.2 +/- 0.1 and 1.1 +/- 0.1 vs 1.7 +/- 0.1 and 1.6 +/- 0.3 mmol/L, P < .01) than white women. The LDL particle size was not different, but obese black women had more LDL subclass IV (17.3% +/- 1.0% vs 12.5% +/- 1.0%, P < .01). In white women, triglycerides and LDL particle size correlated with S(I) (P < .01), whereas cholesterol levels correlated with body fat (P < .05). Low socioeconomic status, low dietary protein intake, and injectable contraceptive use were the major determinants of unfavorable lipid profiles in black women. Black women had lower triglyceride and high-density lipoprotein cholesterol levels and more small dense LDL particles than white women. The major determinants of serum lipids in black women were socioeconomic status and lifestyle factors, whereas in white women, S(I) and body composition most closely correlated with serum lipids.
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| 4. |
- Lindgärde, F, et al.
(författare)
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Overweight is associated with lower serum leptin in Peruvian Indian than in Caucasian women : A dissociation contributing to low blood pressure?
- 2001
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Ingår i: Metabolism. - : Elsevier BV. - 0026-0495 .- 1532-8600. ; 50:3, s. 325-329
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Tidskriftsartikel (refereegranskat)abstract
- We tested whether plasma levels of leptin and insulin are associated with the lower blood pressure in women of Peruvian Indian heritage compared with Caucasian women. A total of 181 women from Peru and 85 from Sweden, aged 20 to 60 years, with normal plasma glucose levels participated in the study. Measurements of anthropometry, blood pressure, and blood tests were performed after overnight fasting. Compared with women from Umeå in Sweden, women from Lima, Peru had higher body mass index (BMI) (26.2 +/- 4.9 v 24.4 +/- 3.8 kg/m(2)), waist circumference (85 +/- 11 v 79 +/- 10 cm), lower systolic blood pressure (99 +/- 15 v 114 +/- 14 mm; P <.001) and diastolic blood pressure (67 +/- 7 v 74 +/- 10 mm; P <.001). In addition, they had a reduction of the ratio of plasma leptin to BMI (0.52 +/- 0.22 v 0.61 +/- 0.36; P <.001), greater plasma insulin (80 +/- 42 v 41 +/- 21 pmol/L), but lower plasma glucose (4.2 +/- 0.5 v 5.1 +/- 0.5 mmol/L; P <.001). Furthermore, the 181 women from Lima had higher plasma triglyceride levels (1.5 +/- 0.8 v 1.3 +/- 0.7; P =.039), but lower plasma high-density lipoprotein (HDL)-cholesterol (1.0 +/- 0.2 v 1.5 +/- 0.4 mmol/L; P <.001) and total plasma cholesterol (5.0 +/- 1.1 v 5.9 +/- 1.3 mmol/L; P <.001) levels. Plasma leptin correlated with blood pressure and BMI in both populations (P <.001). In multiple regression analysis, BMI, but not log leptin, emerged as the determinant for systolic blood pressure. We concluded that women living in Lima have significant lower blood pressure levels in association with elevated plasma insulin concentrations, but lower plasma leptin values adjusted for BMI in comparison with women from northern Sweden. This may suggest that the concept of metabolic syndrome is different among women with Peruvian Indian heritage in comparison to a Caucasian population.
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| 5. |
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| 6. |
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| 7. |
- Ruge, Toralph, et al.
(författare)
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Acute hyperinsulinemia raises plasma interleukin-6 in both nondiabetic and type 2 diabetes mellitus subjects, and this effect is inversely associated with body mass index
- 2009
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Ingår i: Metabolism. - : Elsevier BV. - 0026-0495 .- 1532-8600. ; 58:6, s. 860-866
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Tidskriftsartikel (refereegranskat)abstract
- Hyperinsulinemia is a characteristic of type 2 diabetes mellitus (T2DM) and is believed to play a role in the low-grade inflammation seen in T2DM. The main aim was to study the effect of hyperinsulinemia on adipokines in individuals with different levels of insulin resistance, glycemia, and obesity. Three groups of sex-matched subjects were studied: young healthy subjects (YS; n = 10; mean age, 26 years; body mass index [BMI], 22 kg/m2), patients with T2DM (DS; n = 10; 61 years; BMI, 27 kg/m2), and age- and BMI-matched controls to DS (CS; n = 10; 60 years; BMI, 27 kg/m2). Plasma concentrations of adipokines were measured during a hyperinsulinemic euglycemic clamp lasting 4 hours. Moreover, insulin-stimulated glucose uptake in isolated adipocytes was analyzed to address adipose tissue insulin sensitivity. Plasma interleukin (IL)-6 increased significantly (P ≤ .01) in all 3 groups during hyperinsulinemia. However, the increase was smaller in both DS (P = .06) and CS (P < .05) compared with YS (∼2.5-fold vs ∼4-fold). A significant increase of plasma tumor necrosis factor (TNF) α was observed only in YS. There were only minor or inconsistent effects on adiponectin, leptin, and high-sensitivity C-reactive protein levels during hyperinsulinemia. Insulin-induced rise in IL-6 correlated negatively to BMI (P = .001), waist to hip ratio (P = .05), and baseline (fasting) insulin (P = .03) and IL-6 (P = .02) levels and positively to insulin-stimulated glucose uptake in isolated adipocytes (P = .07). There was no association with age or insulin sensitivity. In a multivariate analysis, also including T2DM/no T2DM, an independent correlation (inverse) was found only between BMI and fold change of IL-6 (r2 = 0.41 for model, P < .005). Hyperinsulinemia per se can produce an increase in plasma IL-6 and TNFα, and this can potentially contribute to the low-grade inflammation seen in obesity and T2DM. However, obesity seems to attenuate the ability of an acute increase in insulin to further raise circulating levels of IL-6 and possibly TNFα.
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| 8. |
- Ruge, Toralph, et al.
(författare)
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Effects of hyperinsulinemia on lipoprotein lipase, angiopoietin-like protein 4, and glycosylphosphatidylinositol-anchored high-density lipoprotein binding protein 1 in subjects with and without type 2 diabetes mellitus
- 2012
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Ingår i: Metabolism. - : Elsevier BV. - 0026-0495 .- 1532-8600. ; 61:5, s. 652-660
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Tidskriftsartikel (refereegranskat)abstract
- Our aims were to compare the systemic effects of insulin on lipoprotein lipase (LPL) in tissues from subjects with different degrees of insulin sensitivity. The effects of insulin on LPL during a 4-hour hyperinsulinemic, euglycemic clamp were studied in skeletal muscle, adipose tissue, and postheparin plasma from young healthy subjects (YS), older subjects with type 2 diabetes mellitus (DS), and older control subjects (CS). In addition, we studied the effects of insulin on the expression of 2 recently recognized candidate genes for control of LPL activity: angiopoietin-like protein 4 (ANGPTL4) and glycosylphosphatidylinositol-anchored high-density lipoprotein binding protein 1. As an effect of insulin, LPL activity decreased by 20% to 25% in postheparin plasma and increased by 20% to 30% in adipose tissue in all groups. In YS, the levels of ANGPTL4 messenger RNA in adipose tissue decreased 3-fold during the clamp. In contrast, there was no significant change in DS or CS. Regression analysis showed that the ability of insulin to reduce the expression of ANGPTL4 was positively correlated with M-values and inversely correlated with factors linked to the metabolic syndrome. Expression of glycosylphosphatidylinositol-anchored high-density lipoprotein binding protein 1 tended to be higher in YS than in DS or CS, but the expression was not affected by insulin in any of the groups. Our data imply that the insulin-mediated regulation of LPL is not directly linked to the control of glucose turnover by insulin or to ANGPTL4 expression in adipose tissue or plasma. Interestingly, the response of ANGPTL4 expression in adipose tissue to insulin was severely blunted in both DS and CS.
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| 9. |
- Thrybom, T, et al.
(författare)
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Effect of serotonin reuptake inhibitor on syndrome development in obese hyperglycemic mice (Umeå ob/ob).
- 2001
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Ingår i: Metabolism. - : Elsevier BV. - 0026-0495 .- 1532-8600. ; 50:2, s. 144-50
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Tidskriftsartikel (refereegranskat)abstract
- These experiments tested the effect of 10 to 30 mg, citalopram/kg body weight on food intake, weight increase, and blood glucose levels in young obese hyperglycemic mice (Umeå ob/ob). A leptin defect in ob/ob mice results in hyperphagia, hyperglycemia, and increased body weight compared with normal mice. Citalopram had no effect on weight increase in ob/ob mice aged 3 to 10 weeks, when the weight increase is most rapid. Citalopram reduced the weight increase at the age 10 to 19 weeks. Food intake reaches a maximum at age 7 to 10 weeks and then decreases. The reduction was more rapid in citalopram-treated mice. The weight of feces paralleled the food intake. Citalopram treatment had no effect on serum insulin levels in 15-week-old mice. Blood sugar values in fed mice reached a peak at age 7 weeks (21.7 +/- 1.7 mmol/L in controls and 22.3 +/- 1 mmol/L in citalopram-treated mice). After that, blood sugar values decreased. The decrease was more pronounced in citalopram-treated mice (P < .01 compared with controls). Blood glucose levels were lower at ages 12 to 15 weeks in female ob/ob control mice (13.6 +/- 2.5 mmol/L v 19.0 +/- 0.6 mmol/L in male control mice; P < .05). The effect of citalopram was the same in male and female mice. There was a close correlation between accumulated food intake and blood glucose values in individual animals. At age 3 to 10 weeks, ob/ob mice have a high beta-cell proliferation rate, and they have large islets of Langerhans. This was not affected by citalopram treatment. Our findings show that the serotonergic system plays a role as a regulator of food intake over shorter periods, and this is also true in the absence of leptin.
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| 10. |
- Zemankova, Katerina, et al.
(författare)
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Acute alcohol consumption downregulates lipoprotein lipase activity in vivo
- 2015
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Ingår i: Metabolism. - : Elsevier. - 0026-0495 .- 1532-8600. ; 64:11, s. 1592-1596
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Tidskriftsartikel (refereegranskat)abstract
- Objective. Acute alcohol consumption can induce hypertriglyceridemia. Such an effect could be explained in part by the influence of alcohol on lipoprotein lipase (LPL) - the key enzyme responsible for triglyceride hydrolysis in circulation. Therefore, we have studied the effects of acute moderate alcohol consumption on LPL activity and on the concentrations of angiopoietin-like proteins 3 and 4 (ANGPTL3 and ANGPTL4), which are known to inhibit LPL. Methods. Two experiments were carried out in 8 healthy volunteers. They received 25 g of alcohol (vodka) in one experiment and water in the other (control). The in vivo function of LPL was estimated using intravenous fat tolerance tests (IVFTT) carried out before, 2 and 4 hours after alcohol administration. At the end of each experiment, LPL activity and mass were measured in post-heparin plasma (PHP). The concentrations of ANGPTL3 and ANGPTL4 in blood were measured before alcohol consumption and at the end of the experiments. Results. LPL activity, as estimated using the IVFTT, was reduced by 25% and 24% two and four hours after the administration of alcohol, respectively, and was not affected in the control experiment. At the end of the experiment, LPL activity in PHP was 23% lower after alcohol consumption than in the controls. The concentrations of ANGPTL3 and ANGPTL4 had dropped to 67% and 86% of baseline values, respectively, at 280 min after alcohol consumption. These levels were not affected in the control experiment. The levels of ANGPTL4 but not those of ANGPTL3 were increased in PHP compared to both baseline values and values at 280 min. Conclusion. The capacity for triglyceride clearance seemed to be acutely reduced by alcohol consumption and the effect persisted for several hours. The levels of LPL activity in PHP were reduced to a similar extent. This reduction in LPL activity could not be explained by the changes in the levels of ANGPTL3 or ANGPTL4, which both decreased. (C) 2015 Elsevier Inc. All rights reserved.
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