| 1. |
- Edholm, David, et al.
(författare)
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Preoperative 4-week low-calorie diet reduces liver volume and intrahepatic fat, and facilitates laparoscopic gastric bypass in morbidly obese
- 2011
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Ingår i: Obesity Surgery. - : Springer Science and Business Media LLC. - 0960-8923 .- 1708-0428. ; 21:3, s. 345-350
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Tidskriftsartikel (refereegranskat)abstract
- BACKGROUND: The aim of this study was to explore changes in liver volume and intrahepatic fat in morbidly obese patients during 4 weeks of low-calorie diet (LCD) before surgery and to investigate if these changes would facilitate the following laparoscopic gastric bypass.METHODS: Fifteen female patients (121.3 kg, BMI 42.9) were treated preoperatively in an open study with LCD (800-1,100 kcal/day) during 4 weeks. Liver volume and fat content were assessed by magnetic resonance imaging and spectroscopy before and after the LCD treatment.RESULTS: Liver appearance and the complexity of the surgery were scored at the operation. Eighteen control patients (114.4 kg, BMI 40.8), without LCD were scored similarly. Average weight loss in the LCD group was 7.5 kg, giving a mean weight of 113.9 kg at surgery. Liver volume decreased by 12% (p < 0.001) and intrahepatic fat by 40% (p < 0.001). According to the preoperative scoring, the size of the left liver lobe, sharpness of the liver edge, and exposure of the hiatal region were improved in the LCD group compared to the controls (all p < 0.05).CONCLUSIONS: The overall complexity of the surgery was perceived lower in the LCD group (p < 0.05), due to improved exposure and reduced psychological stress (both p < 0.05). Four weeks of preoperative LCD resulted in a significant decrease in liver volume and intrahepatic fat content, and facilitated the subsequent laparoscopic gastric bypass as scored by the surgeon
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| 2. |
- Kullberg, Joel, et al.
(författare)
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Gastric bypass promotes more lipid mobilization than a similar weight loss induced by low-calorie diet
- 2011
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Ingår i: Journal of Obesity. - : Hindawi Limited. - 2090-0708 .- 2090-0716. ; 2011, s. 959601-
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Tidskriftsartikel (refereegranskat)abstract
- Background.Recently, we found large reductions in visceral and subcutaneous fat one month after gastric bypass (GBP), without any change in liver fat content.Purpose.Firstly to characterize weight loss-induced lipid mobilization after one month with preoperative low-calorie diet (LCD) and a subsequent month following GBP, and secondly, to discuss the observations with reference to our previous published findings after GBP intervention alone.Methods.15 morbidly obese women were studied prior to LCD, at GBP, and one month after GBP. Effects on metabolism were measured by magnetic resonance techniques and blood tests.Results.Body weight was similarly reduced after both months (mean: -8.0 kg, n = 13). Relative body fat changes were smaller after LCD than after GBP (-7.1 ± 3.6% versus -10 ± 3.2%, P = .029, n = 13). Liver fat fell during the LCD month (-41%, P = .001, n = 13) but was unaltered one month after GBP (+12%).Conclusion.Gastric bypass seems to cause a greater lipid mobilization than a comparable LCD-induced weight loss. One may speculate that GBP-altered gastrointestinal signalling sensitizes adipose tissue to lipolysis, promoting the changes observed.
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| 3. |
- Edholm, David, et al.
(författare)
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Changes in liver volume and body composition during 4 weeks of low calorie diet before laparoscopic gastric bypass
- 2015
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Ingår i: Surgery for Obesity and Related Diseases. - : Elsevier BV. - 1550-7289 .- 1878-7533. ; 11:3, s. 602-606
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Tidskriftsartikel (refereegranskat)abstract
- BACKGROUND:Weight loss before laparoscopic Roux-en-Y gastric bypass (LRYGB) is desirable, because it can reduce liver volume and thereby facilitate the procedure. The optimal duration of a low-calorie diet (LCD) has not been established. The objective of this study was to assess changes in liver volume and body composition during 4 weeks of LCD.METHODS:Ten women (aged 43±8.9 years, 114±12.1 kg, and body mass index 42±2.6 kg/m2) were examined on days 0, 3, 7, 14, and 28 after commencing the LCD. At each evaluation, body composition was assessed through bioelectric impedance analysis, and liver volume and intrahepatic fat content were assessed by magnetic resonance imaging. Serum and urine samples were obtained. Questionnaires regarding quality of life and LCD-related symptoms were administered.RESULTS:In total, mean weight decreased by 7.4±1.2 kg (range 5.7-9.1 kg), and 71% of the weight loss consisted of fat mass according to bioelectric impedance analysis. From day 0 to day 3, the weight loss (2.0 kg) consisted mainly of water. Liver volume decreased by 18%±6.2%, from 2.1 to 1.7 liters (P<.01), during the first 2 weeks with no further change thereafter. A continuous 51%±16% decrease was seen in intrahepatic fat content. Systolic blood pressure, insulin, and lipids improved, while liver enzymes, glucose levels, and quality of life were unaffected.CONCLUSION:A significant decrease in liver volume (18%) occurred during the first 2 weeks of LCD treatment, and intrahepatic fat gradually decreased throughout the study period. A preoperative 2-week LCD treatment seems sufficient in similar patients.
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| 4. |
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| 5. |
- 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 .- 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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| 6. |
- Johansson, Lars, et al.
(författare)
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Lipid Mobilization Following Roux-en-Y Gastric Bypass Examined by Magnetic Resonance Imaging and Spectroscopy
- 2008
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Ingår i: Obesity Surgery. - : Springer Science and Business Media LLC. - 0960-8923 .- 1708-0428. ; 18:10, s. 1297-1304
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Tidskriftsartikel (refereegranskat)abstract
- BACKGROUND: Recent developments of magnetic resonance imaging (MRI) and spectroscopy have made it possible to quantify lipid deposited in different tissues. To what extent an improvement of glucose tolerance shortly after Roux-en-Y gastric bypass surgery (RYGBP) is reflected in lipid levels in liver and skeletal muscle, markers of insulin resistance, has not been clarified. METHODS: Whole-body MRI and MR spectroscopy (MRS) of liver and muscle and measurements of biochemical markers of glucose and lipid metabolism were performed at baseline and 1, 6, and 12 months following surgery in seven morbidly obese women. Volumes of adipose tissue depots and liver and muscle lipids were assessed from the MRI/MRS data. RESULTS: At 1 month postoperatively, body mass index and visceral and subcutaneous adipose tissues were reduced by 9%, 26%, and 10%, respectively, whereas no reductions in intrahepatocellular or skeletal intramyocellular lipid concentrations were found. Free fatty acid and beta-hydroxybutyrate levels were elevated two- and sixfold, respectively; glucose and insulin levels were lowered, indicating increased insulin sensitivity. Further weight loss up to 1 year was associated with reductions in all investigated lipid depots investigated, with the exception of the intramyocellular compartment. CONCLUSION: RYGBP causes rapid lipid mobilization from visceral and subcutaneous adipose depots and enhanced free fatty acid flux to the liver. An exceptional disconnection between liver fat and insulin sensitivity occurs in the early dynamic phase after surgery. However, in the late phase, the energy restriction imposed by the surgical procedure also reduces the liver lipids, but not the intramyocellular lipids.
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| 7. |
- Strand, Robin, 1978-, et al.
(författare)
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A concept for holistic whole body MRI data analysis, Imiomics
- 2017
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Ingår i: PLOS ONE. - : Public Library of Science (PLoS). - 1932-6203. ; 12:2
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Tidskriftsartikel (refereegranskat)abstract
- Purpose: To present and evaluate a whole-body image analysis concept, Imiomics (imaging omics) and an image registration method that enables Imiomics analyses by deforming all image data to a common coordinate system, so that the information in each voxel can be compared between persons or within a person over time and integrated with non-imaging data.Methods: The presented image registration method utilizes relative elasticity constraints of different tissue obtained from whole-body water-fat MRI. The registration method is evaluated by inverse consistency and Dice coefficients and the Imiomics concept is evaluated by example analyses of importance for metabolic research using non-imaging parameters where we know what to expect. The example analyses include whole body imaging atlas creation, anomaly detection, and cross-sectional and longitudinal analysis.Results: The image registration method evaluation on 128 subjects shows low inverse consistency errors and high Dice coefficients. Also, the statistical atlas with fat content intensity values shows low standard deviation values, indicating successful deformations to the common coordinate system. The example analyses show expected associations and correlations which agree with explicit measurements, and thereby illustrate the usefulness of the proposed Imiomics concept.Conclusions: The registration method is well-suited for Imiomics analyses, which enable analyses of relationships to non-imaging data, e.g. clinical data, in new types of holistic targeted and untargeted big-data analysis.
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| 8. |
- Strand, Robin, 1978-, et al.
(författare)
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Holistic whole-body MRI image analysis
- 2016
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Ingår i: Symposium of the Swedish Society for Automated Image Analysis, Uppsala, Sweden, (SSBA).
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Konferensbidrag (övrigt vetenskapligt/konstnärligt)
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| 9. |
- 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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