| 1. |
- Johansson, Hans-Erik, 1960-, et al.
(författare)
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Energy restriction in obese women suggest linear reduction of hepatic fat content and time-dependent metabolic improvements
- 2019
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Ingår i: Nutrition & Diabetes. - : Springer Science and Business Media LLC. - 2044-4052. ; 9:1
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Tidskriftsartikel (refereegranskat)abstract
- Energy restriction reduces liver fat, improves hepatic insulin resistance and lipid metabolism. However, temporal data in which these metabolic improvements occur and their interplay is incomplete. By performing repeated MRI scans and blood analysis at day 0, 3, 7, 14 and 28 the temporal changes in liver fat and related metabolic factors were assessed at five times during a low-calorie diet (LCD, 800-1100 kcal/day) in ten obese non-diabetic women (BMI 41.7 ± 2.6 kg/m2) whereof 6 had NAFLD. Mean weight loss was 7.4 ± 1.2 kg (0.7 kg/day) and liver fat decreased by 51 ± 16%, resulting in only three subjects having NAFLD at day 28. Marked alteration of insulin, NEFA, ALT and 3-hydroxybuturate was evident 3 days after commencing LCD, whereas liver fat showed a moderate but a linear reduction across the 28 days. Other circulating-liver fat markers (e.g. triglycerides, adiponectin, stearoyl-CoA desaturase-1 index, fibroblast growth factor 21) demonstrated modest and variable changes. Marked elevations of NEFA, 3-hydroxybuturate and ALT concentrations occurred until day 14, likely reflecting increased tissue lipolysis, fat oxidation and upregulated hepatic fatty acid oxidation. In summary, these results suggest linear reduction in liver fat, time-specific changes in metabolic markers and insulin resistance in response to energy restriction.
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| 2. |
- Petrus, P, et al.
(författare)
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Depot-specific differences in fatty acid composition and distinct associations with lipogenic gene expression in abdominal adipose tissue of obese women
- 2017
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Ingår i: International Journal of Obesity. - : Springer Science and Business Media LLC. - 0307-0565 .- 1476-5497. ; 41:8, s. 1295-1298
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Tidskriftsartikel (refereegranskat)abstract
- Cardiometabolic diseases are primarily linked to enlarged visceral adipose tissue (VAT). However, some data suggest heterogeneity within the subcutaneous adipose tissue (SAT) depot with potential metabolic differences between the superficial SAT (sSAT) and deep SAT (dSAT) compartments. We aimed to investigate the heterogeneity of these three depots with regard to fatty acid (FA) composition and gene expression. Adipose tissue biopsies were collected from 75 obese women undergoing laparoscopic gastric bypass surgery. FA composition and gene expression were determined with gas chromatography and quantitative real-time-PCR, respectively. Stearoyl CoA desaturase-1 (SCD-1) activity was estimated by product-to-precursor FA ratios. All polyunsaturated FAs (PUFA) with 20 carbons were consistently lower in VAT than either SAT depots, whereas essential PUFA (linoleic acid, 18:2n-6 and α-linolenic acid, 18:3n-3) were similar between all three depots. Lauric and palmitic acid were higher and lower in VAT, respectively. The SCD-1 product palmitoleic acid as well as estimated SCD-1 activity was higher in VAT than SAT. Overall, there was a distinct association pattern between lipid metabolizing genes and individual FAs in VAT. In conclusion, SAT and VAT are two distinct depots with regard to FA composition and expression of key lipogenic genes. However, the small differences between sSAT and dSAT suggest that FA metabolism of SAT is rather homogenous.
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| 3. |
- Petrus, Paul, et al.
(författare)
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Saturated fatty acids in human visceral adipose tissue are associated with increased 11-beta-hydroxysteroid-dehydrogenase type 1 expression
- 2015
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Ingår i: Lipids in Health and Disease. - : Springer Science and Business Media LLC. - 1476-511X. ; 14
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Tidskriftsartikel (refereegranskat)abstract
- Background: Visceral fat accumulation is associated with metabolic disease. It is therefore relevant to study factors that regulate adipose tissue distribution. Recent data shows that overeating saturated fatty acids promotes greater visceral fat storage than overeating unsaturated fatty acids. Visceral adiposity is observed in states of hypercortisolism, and the enzyme 11-beta-hydroxysteroid-dehydrogenase type 1 (11 beta-hsd1) is a major regulator of cortisol activity by converting inactive cortisone to cortisol in adipose tissue. We hypothesized that tissue fatty acid composition regulates body fat distribution through local effects on the expression of 11 beta-hsd1 and its corresponding gene (HSD11B1) resulting in altered cortisol activity. Findings: Visceral- and subcutaneous adipose tissue biopsies were collected during Roux-en-Y gastric bypass surgery from 45 obese women (BMI; 41 +/- 4 kg/m(2)). The fatty acid composition of each biopsy was measured and correlated to the mRNA levels of HSD11B1. 11 beta-hsd1 protein levels were determined in a subgroup (n = 12) by western blot analysis. Our main finding was that tissue saturated fatty acids (e.g. palmitate) were associated with increased 11 beta-hsd1 gene- and protein-expression in visceral but not subcutaneous adipose tissue. Conclusions: The present study proposes a link between HSD11B1 and saturated fatty acids in visceral, but not subcutaneous adipose tissue. Nutritional regulation of visceral fat mass through HSD11B1 is of interest for the modulation of metabolic risk and warrants further investigation.
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| 4. |
- Skogar, Martin, et al.
(författare)
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Preserved Fat-Free Mass after Gastric Bypass and Duodenal Switch
- 2017
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Ingår i: Obesity Surgery. - : Springer Science and Business Media LLC. - 0960-8923 .- 1708-0428. ; 27:7, s. 1735-1740
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Tidskriftsartikel (refereegranskat)abstract
- BACKGROUND: Concerns for the possibility of an excessive loss of fat-free mass (FFM) and resting metabolic rate (RMR) after bariatric surgery, such as Roux-en-Y gastric bypass (RYGB) and duodenal switch (BPD/DS), have been raised.OBJECTIVES: This study aims to examine body composition and RMR in patients after RYGB and BPD/DS and in non-operated controls.METHODS: Body composition and RMR were studied with Bod Pod and indirect calorimetry in weight-stable RYGB (n = 15) and BPD/DS patients (n = 12) and compared with non-operated controls (n = 17). All patients were 30-55 years old and weight stable with BMI 28-35 kg/m(2).RESULTS: FFM% was 58% (RYGB), 61% (BPD/DS), and 58% (controls). Body composition did not differ after RYGB and BPD/DS compared to controls, despite 27 and 40% total body weight loss, respectively. No difference in RMR or RMR/FFM was observed (1539, 1617, and 1490 kcal/24 h; and 28.9, 28.4, and 28.8 kcal/24 h/kg).CONCLUSION: Weight-stable patients with BMI 28-35 kg/m(2) after RYGB and BPD/DS have a body composition and RMR similar to that of non-operated individuals within the same BMI interval.
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| 5. |
- Straniero, S., et al.
(författare)
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Acute caloric restriction counteracts hepatic bile acid and cholesterol deficiency in morbid obesity
- 2017
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Ingår i: Journal of Internal Medicine. - : Wiley. - 0954-6820 .- 1365-2796. ; 281:5, s. 507-517
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Tidskriftsartikel (refereegranskat)abstract
- BackgroundBile acid (BA) synthesis is regulated by BA signalling in the liver and by fibroblast growth factor 19 (FGF19), synthesized and released from the intestine. In morbid obesity, faecal excretion and hepatic synthesis of BAs and cholesterol are strongly induced and caloric restriction reduces their faecal excretion considerably. We hypothesized that the high intestinal food mass in morbidly obese subjects promotes faecal excretion of BAs and cholesterol, thereby creating a shortage of both BAs and cholesterol in the liver.MethodsTen morbidly obese women (BMI 42 ± 2.6 kg m−2) were monitored on days 0, 3, 7, 14 and 28 after beginning a low‐calorie diet (800–1100 kcal day−1). Serum was collected and liver size and fat content determined. Synthesis of BAs and cholesterol was evaluated from serum markers, and the serum levels of lipoproteins, BAs, proprotein convertase subtilisin/kexin type 9 (PCSK9), insulin, glucose and FGF19 were monitored. Fifty‐four nonobese women (BMI <25 kg m−2) served as controls.ResultsAt baseline, synthesis of both BAs and cholesterol and serum levels of BAs and PCSK9 were elevated in the obese group compared to controls. Already after 3 days on a low‐calorie diet, BA and cholesterol synthesis and serum BA and PCSK9 levels normalized, whereas LDL cholesterol increased. FGF19 and triglyceride levels were unchanged, and liver volume was reduced by 10%.ConclusionsThe results suggest that hepatic BAs and cholesterol are deficient in morbid obesity. Caloric restriction rapidly counteracts these deficiencies, normalizing BA and cholesterol synthesis and circulating PCSK9 levels, indicating that overproduction of cholesterol in enlarged peripheral tissues cannot explain this phenotype. We propose that excessive food intake promotes faecal loss of BAs and cholesterol contributing to their hepatic deficiencies.
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