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Aims Body weight loss improves insulin resistance and growth hormone secretion in obesity, which may be regulated by leptin according to preclinical studies. How changes in leptin, lipids and insulin sensitivity after bariatric (metabolic) surgery affect the human growth hormone system is yet unclear. Participants and methods People with obesity (OBE, n = 79, BMI 50.8 ± 6.3 kg/m2) were studied before, 2, 12, 24 and 52 weeks after metabolic surgery and compared to lean healthy humans (control; CON, n = 24, BMI 24.3 ± 3.1 kg/m2). Tissue-specific insulin sensitivity was assessed by hyperinsulinemic-euglycemic clamps with D-[6,6-2H2]glucose. Fasting leptin, growth hormone (GH), insulin-like growth factor 1 (IGF-1) and IGF-binding proteins (IGFBP1, IGFBP3) were measured using ELISA. Results At baseline, OBE exhibited higher glycemia and leptinemia as well as pronounced peripheral, adipose tissue and hepatic insulin resistance compared to CON. GH and IGFBP1 were lower, while IGF1 was comparable between groups. At 52 weeks, OBE had lost 33% body weight and doubled their peripheral insulin sensitivity, which was paralleled by continuous increases in GH, IGF-1 and IGFBP1 as well as decrease in leptin. The rise in GH correlated with reductions in free fatty acids, adipose tissue insulin resistance and insulinemia, but not with changes in body weight, peripheral insulin sensitivity, glycemia or leptinemia. The rise in IGF-1 correlated with reduction in high-sensitive C-reactive protein. Conclusion Reversal of alterations of the GH-IGF-1 axis after surgically-induced weight loss is unlikely related to improved leptin secretion and/or insulin sensitivity, but is rather associated with restored adipose tissue function and reduced low-grade inflammation.

Adipose tissue dysfunction is involved in the development of insulin resistance and is responsible for excessive lipid delivery to other organs such as the liver. We tested the hypothesis that impaired mitochondrial function is a common feature of subcutaneous (SAT) and visceral adipose tissue (VAT), but may differently contribute to adipose tissue insulin resistance (IR) in obesity, non-alcoholic fatty liver (NAFL) and steatohepatitis (NASH).In this cross-sectional study, we analyzed tissue-specific insulin sensitivity using stable isotope dilution and hyperinsulinemic-normoglycemic clamp tests. We also assessed mitochondrial respiration, mRNA and protein expression, and tissue morphology in biopsies of SAT and VAT from obese humans without NAFL, with NAFL or with NASH (n = 22/group).Compared to individuals without liver disease, persons with NAFL and NASH had about 30% (p = 0.010) and 33% (p = 0.002) lower maximal mitochondrial respiration, respectively, in VAT, but not in SAT. The lower maximal mitochondrial respiration of VAT was associated with lower adipose tissue insulin sensitivity (β = 0.985, p = 0.041) and with increased VAT protein expression of tumor necrosis factor A across all groups (β = -0.085, p = 0.040). VAT from individuals with NASH was characterized by lower expression of oxidative phosphorylation complex IV (p = 0.042) and higher mRNA expression of the macrophage marker CD68 (p = 0.002) than VAT from participants without NAFL.Humans with non-alcoholic fatty liver disease have distinct abnormalities of VAT energy metabolism, which correlate with adipose tissue dysfunction and may favor progression of NAFL to NASH.Adipose tissue (commonly called body fat) can be found under the skin (subcutaneous) or around internal organs (visceral). Dysfunction of adipose tissue can cause insulin resistance and lead to excess delivery of fat to other organs such as the liver. Herein, we show that dysfunction specifically in visceral adipose tissue was associated with fatty liver disease.NCT01477957.

Impaired adipose tissue (AT) function closely associates with obesity, type 2 diabetes and nonalcoholic fatty liver disease (NAFLD) . Mitochondrial oxidative phosphorylation (OXPHOS) capacity of AT improves after weight loss surgery. However, it is not clear if the improvement is affected by the presence of NAFLD before surgery. We examined 52 severely obese people exhibiting no histological liver disease (OBE_CON) , simple steatosis (OBE_NAFL) or steatohepatitis (OBE_NASH) before (0 weeks) , 12 and 52 weeks after bariatric surgery. Whole-body insulin sensitivity was measured by hyperinsulinemic euglycemic clamps. OXPHOS capacity of subcutaneous AT was assessed by high-resolution respirometry. Transcript levels of TNFα in AT were quantified by RT-PCR. Before surgery, OBE_NASH presented with lower insulin sensitivity and higher HbA1c compared to OBE_CON and OBE_NAFL (all p In conclusion, in severe obesity, weight loss-related improvements in AT OXPHOS capacity may be mediated to a great extent by reduced AT inflammation in people without liver disease; however, with pre-surgery manifestation of NASH and worsening of metabolic control, residual systemic subclinical inflammation may attenuate the improvement of AT OXPHOS capacity after bariatric surgery. Disclosure S.Kahl: None. G.Heilmann: None. I.Esposito: None. M.Schlensak: None. M.Roden: Advisory Panel; Eli Lilly and Company, Research Support; Boehringer Ingelheim International GmbH, Nutricia, Speaker's Bureau; Novo Nordisk. K.Strassburger: None. S.Gancheva: None. N.Saatmann: None. C.Granata: None. C.Herder: Research Support; Sanofi. K.Pafili: None. J.Puetzer-furmanczak: None. T.Sarabhai: None. Funding German Federal Ministry of Health; Ministry of Culture and Science of the State North Rhine-Westphalia;German Federal Ministry of Education and Research;European Funds for Regional Development (EFRE-0400191) ;EUREKA Eurostars-2 (E!113230DIA-PEP) ;German Science Foundation (CRC/SFB1116/2 B12; RTG/GRK 2576 vivid, Project 3) ;Schmutzler Stiftung

The mechanisms underlying improved insulin sensitivity after surgically-induced weight loss are still unclear. We monitored skeletal muscle metabolism in obese individuals before and over 52 weeks after metabolic surgery. Initial weight loss occurs in parallel with a decrease in muscle oxidative capacity and respiratory control ratio. Persistent elevation of intramyocellular lipid intermediates, likely resulting from unrestrained adipose tissue lipolysis, accompanies the lack of rapid changes in insulin sensitivity. Simultaneously, alterations in skeletal muscle expression of genes involved in calcium/lipid metabolism and mitochondrial function associate with subsequent distinct DNA methylation patterns at 52 weeks after surgery. Thus, initial unfavorable metabolic changes including insulin resistance of adipose tissue and skeletal muscle precede epigenetic modifications of genes involved in muscle energy metabolism and the long-term improvement of insulin sensitivity., Surgical weight-loss interventions improve insulin sensitivity via incompletely understood mechanisms. Here the authors assess skeletal muscle epigenetic changes in individuals with obesity following metabolic surgery and compare them with data from individuals without obesity.

OBJECTIVE Individuals with type 2 diabetes are at higher risk of progression of nonalcoholic fatty liver (steatosis) to steatohepatitis (NASH), fibrosis, and cirrhosis. The hepatic metabolism of obese individuals adapts by upregulation of mitochondrial capacity, which may be lost during the progression of steatosis. However, the role of type 2 diabetes with regard to hepatic mitochondrial function in NASH remains unclear. RESEARCH DESIGN AND METHODS We therefore examined obese individuals with histologically proven NASH without (OBE) (n = 30; BMI 52 ± 9 kg/m2) or with type 2 diabetes (T2D) (n = 15; 51 ± 7 kg/m2) as well as healthy individuals without liver disease (CON) (n = 14; 25 ± 2 kg/m2). Insulin sensitivity was measured by hyperinsulinemic-euglycemic clamps with d-[6,6-2H2]glucose. Liver biopsies were used for assessing mitochondrial capacity by high-resolution respirometry and protein expression. RESULTS T2D and OBE had comparable hepatic fat content, lobular inflammation, and fibrosis. Oxidative capacity in liver tissue normalized for citrate synthase activity was 59% greater in OBE than in CON, whereas T2D presented with 33% lower complex II–linked oxidative capacity than OBE and higher H2O2 production than CON. Interestingly, those with NASH and hepatic fibrosis score ≥1 had lower oxidative capacity and antioxidant defense than those without fibrosis. CONCLUSIONS Loss of hepatic mitochondrial adaptation characterizes NASH and type 2 diabetes or hepatic fibrosis and may thereby favor accelerated disease progression.

Adipose dysfunction may drive the development of insulin resistance, type 2 diabetes (T2D) and nonalcoholic (NA) fatty liver disease (NAFLD), comprising NA fatty liver and steatohepatitis (NAFL and NASH). Possible underlying mechanism comprise impaired lipid storage or mitochondrial oxidation favoring increased fatty acid flux to other tissues. Thus, we examined subcutaneous (SAT) and visceral adipose tissue (VAT) mitochondrial capacity in humans with different degrees of insulin resistance and histologically proven NAFLD. Obese people without NAFL (OBE-CON, n=20, 38±8 years, body mass index 53±6 kg/m2, 10% T2D), with NAFL (OBE-NAFL, n=20, 40±8 years, 51±5 kg/m2, 25% T2D) or NASH (OBE-NASH, n=20, 42±10 years, 51±6 kg/m2, 40% T2D) underwent metabolic phenotyping and tissue biopsies. O2 flux rates from different substrates were measured with high resolution respirometry in SAT and VAT. In VAT, maximal uncoupled respiration was lower in OBE-NAFL (least square means (LSM): 0.46 pmol*mg wet weight–1*s–1 [95% confidence interval 0.21;0.71], p In conclusion, oxidative capacity is downregulated in VAT, but not in SAT of obese humans with NAFLD, which may be related to the degree of insulin resistance. Disclosure K. Pafili: None. M. Schlensak: None. M. Roden: Advisory Panel; Self; Allergan plc, Bristol-Myers Squibb Company, Novo Nordisk A/S, Research Support; Self; Boehringer Ingelheim International GmbH, Danone Nutricia, Sanofi-Aventis Deutschland GmbH. S. Kahl: None. D. Pesta: None. K. Strassburger: None. L. Mastrototaro: None. J. Puetzer-furmanczak: None. B. Dewidar: None. T. Sarabhai: None. I. Esposito: None.

IntroductionSphingolipid accumulation has been linked to obesity, type 2 diabetes and non-alcoholic fatty liver disease (NAFLD). A recent study showed that depletion of dihydroceramide desaturase-1 (DES-1) in adipose and/or liver tissue decreases ceramide-to-dihydroceramide ratios (ceramide/dihydroceramide) in several tissues and improves the metabolic profile in mice. We tested the hypothesis that ceramide/dihydroceramide would also be elevated and relate positively to liver fat content and insulin resistance in humans.Research design and methodsThus, we assessed total and specific ceramide/dihydroceramide in various biosamples of 7 lean and 21 obese volunteers without or with different NAFLD stages, who were eligible for abdominal or bariatric surgery, respectively. Biosamples were obtained from serum, liver, rectus abdominis muscle as well as subcutaneous abdominal and visceral adipose tissue during surgery.ResultsSurprisingly, certain serum and liver ceramide/dihydroceramide ratios were reduced in both obesity and non-alcoholic steatohepatitis (NASH) and related inversely to liver fat content. Specifically, hepatic ceramide/dihydroceramide (species 16:0) related negatively to hepatic mitochondrial capacity and lipid peroxidation. In visceral adipose tissue, ceramide/dihydroceramide (species 16:0) associated positively with markers of inflammation.ConclusionThese results failed to confirm the relationships of ceramide/dihydroceramide in humans with different degree of insulin resistance. However, the low hepatic ceramide/dihydroceramide favor a role for dihydroceramide accumulation in NASH, while a specific ceramide/dihydroceramide ratio in visceral adipose tissue suggests a role of ceramides in obesity-associated low-grade inflammation.

OBJECTIVE Insulin resistance and nonalcoholic fatty liver disease have been linked to several lipid metabolites in animals, but their role in humans remains unclear. This study examined the relationship of sphingolipids with hepatic and peripheral metabolism in 21 insulin-resistant obese patients without (NAFL−) or with (NAFL+) nonalcoholic fatty liver and nonalcoholic steatohepatitis (NASH) and 7 healthy lean individuals undergoing tissue biopsies during bariatric or elective abdominal surgery. RESEARCH DESIGN AND METHODS Hyperinsulinemic-euglycemic clamps with d-[6,6-2H2]glucose were performed to quantify tissue-specific insulin sensitivity. Hepatic oxidative capacity, lipid peroxidation, and the phosphorylated-to-total c-Jun N-terminal kinase (pJNK-to-tJNK) ratio were measured to assess mitochondrial function, oxidative stress, and inflammatory activity. RESULTS Hepatic total ceramides were higher by 50% and 33% in NASH compared with NAFL+ and NAFL−, respectively. Only in NASH were hepatic dihydroceramides (16:0, 22:0, and 24:1) and lactosylceramides increased. Serum total ceramides and dihydroceramides (hepatic dihydroceramides 22:0 and 24:1) correlated negatively with whole-body but not with hepatic insulin sensitivity. Hepatic maximal respiration related positively to serum lactosylceramide subspecies, hepatic sphinganine, and lactosylceramide 14:0. Liver lipid peroxides (total ceramides, sphingomyelin 22:0) and the pJNK-to-tJNK ratio (ceramide 24:0; hexosylceramides 22:0, 24:0, and 24:1) all positively correlated with the respective hepatic sphingolipids. CONCLUSIONS Sphingolipid species are not only increased in insulin-resistant humans with NASH but also correlate with hepatic oxidative stress and inflammation, suggesting that these lipids may play a role during progression of simple steatosis to NASH in humans.

Weight loss-induced improvement in insulin sensitivity (IS) has been related to enhanced muscle energy metabolism. Thus, we hypothesized that weight loss due to bariatric surgery may induce epigenomic changes, which in turn modify mitochondrial function and intracellular lipids. We previously reported that IS fails to improve at 2 weeks (2 w), but then continuously increases until 52 weeks (52 w) after surgery. Now, we monitored muscle mitochondrial function and lipid intermediates in 49 obese humans (OBE; 40±10 years, BMI 51±7 kg/m2) before and for 52 w after bariatric surgery. Genome-wide gene expression and DNA methylation were analyzed in a subgroup of 16 OBE. Initial weight loss increases muscle oxidative capacity by 11% at 2 w, but transient elevation of certain muscle diacylglycerols resulting from unrestrained adipose lipolysis prevents from rapid improvement in IS. At 52 w, both mitochondrial function and intracellular lipids are comparable to lean humans. Acute alterations in expression of 1287 genes involved primarily in mitochondrial function, transcriptional regulation, protein transport, fatty acid metabolism and inflammatory processes, but not changes in DNA methylation, underlie the transient upregulation of mitochondrial function and lipolysis. At 52 w, 1091CpGs are differentially methylated, which relates to improved IS. Specifically, epigenetic alterations at 52 w in FTO gene, encoding an α-ketoglutarate dependent dioxygenase, and TOMM7 gene, encoding a translocase of the outer mitochondrial membrane, contribute to reprogramming transient changes in mRNA expression at 2 w. In conclusion, initial metabolic changes after weight loss induce epigenetic modification of genes involved in muscle energy metabolism, which in turn leads to long-term beneficial changes in gene expression. Disclosure S. Gancheva: None. M. Ouni: None. C. Koliaki: None. T. Jelenik: None. D.F. Markgraf: None. J. Szendroedi: None. M. Schlensak: None. A. Schuermann: None. M. Roden: Speaker's Bureau; Self; Boehringer Ingelheim GmbH. Research Support; Self; Boehringer Ingelheim GmbH. Consultant; Self; Poxel SA. Research Support; Self; Danone Nutricia Early Life Nutrition, GlaxoSmithKline plc., Nutricia Advanced Medical Nutrition, Sanofi.

AIMS The duodenal-jejunal bypass liner (DJBL) is an endoscopic device mimicking surgical duodenal-jejunal bypass, and is indicated for the treatment of obesity-associated type 2 diabetes mellitus. This analysis was conducted to evaluate the efficacy and safety of the DJBL in comparison to lifestyle changes and antidiabetic drugs. MATERIALS AND METHODS To determine the efficacy and long-term safety of the DJBL, data concerning 235 obese patients with type 2 diabetes mellitus from the German DJBL registry were analysed. For comparison with standard treatment, propensity-score-matching with patients from the German DPV registry, including the matching parameters sex, age, diabetes duration, baseline BMI and baseline HbA1c, was applied. The final matched cohort consisted of 111 patients in the DJBL group and 222 matched control DPV patients. RESULTS Mean treatment time with the DJBL was 47.5 ± 12.2 weeks, mean BMI reduction was 5.0 kg/m2 (P

A novel-approach for treatment of obesity and diabetes mellitus type 2 (T2DM) is represented by the endoscopic duodenal-jejunal bypass liner (DJBL). Recent data from the German DJBL registry provide evidence for substantial efficacy of the DJBL during the implantation period in obese patients with T2DM. However, little is known about the trends of glycemic control, BMI, and comorbidities after explantation of the DJBL, which have been investigated in the registry in this report. Patients were selected from the registry if they had a dataset at implantation, explantation, and at least one time point after explantation of the DJBL (n = 77). We also investigated a subgroup of patients with available data at least 1 year (–2 weeks) after explantation of the DJBL (n = 32). For a mean BMI at implantation and a mean follow-up period, an increase of BMI of 2.1 kg/m2 (CI 0.8–3.2; p = 0.013) had to be expected (for HbA1c 0.3% (CI − 0.0–0.7; p = n.s.), respectively). In the subgroup analysis, HbA1c and BMI increased after explantation of the DJBL but stayed significantly below baseline levels. Meanwhile, the mean number of antidiabetic drugs slightly increased. There was deterioration seen for blood pressure and LDL cholesterol over the postexplantation period to approximately baseline levels (or higher). With this data, we show that improvement of HbA1c and BMI can be partly maintained over a time of nearly 1-year postexplantation of the DJBL. However, for HbA1c, this may be biased by intensified medical treatment and effects deteriorated with time after explantation. These results suggest that implantation of the DJBL needs to be integrated in a long-term weight management program as most of other interventions in obese patients with T2DM. ClinicalTrials.gov Identifier: NCT02731859

Summary The association of hepatic mitochondrial function with insulin resistance and non-alcoholic fatty liver (NAFL) or steatohepatitis (NASH) remains unclear. This study applied high-resolution respirometry to directly quantify mitochondrial respiration in liver biopsies of obese insulin-resistant humans without (n = 18) or with (n = 16) histologically proven NAFL or with NASH (n = 7) compared to lean individuals (n = 12). Despite similar mitochondrial content, obese humans with or without NAFL had 4.3- to 5.0-fold higher maximal respiration rates in isolated mitochondria than lean persons. NASH patients featured higher mitochondrial mass, but 31%–40% lower maximal respiration, which associated with greater hepatic insulin resistance, mitochondrial uncoupling, and leaking activity. In NASH, augmented hepatic oxidative stress (H 2 O 2 , lipid peroxides) and oxidative DNA damage (8-OH-deoxyguanosine) was paralleled by reduced anti-oxidant defense capacity and increased inflammatory response. These data suggest adaptation of the liver ("hepatic mitochondrial flexibility") at early stages of obesity-related insulin resistance, which is subsequently lost in NASH.

BACKGROUND: Most studies on bariatric surgery outcomes are performed as clinical trials or reflect the clinical experience in single centers. The status of bariatric surgery in Germany has been examined with the cooperation of clinics and hospitals at the Institute of Quality Assurance in Surgery at the Otto-von-Guericke University of Magdeburg (Germany) since January 1, 2005. METHODS: In this prospective multicenter observational study, the data obtained for all primary bariatric procedures, including all repeated operations, performed on consecutive patients with morbid obesity at participating hospitals from 2005 to 2007 were prospectively collected using an internet online data registry. Perioperative characteristics such as the spectrum of diagnostic measurements, type of surgical procedures, and short-and long-term out comes were investigated. RESULTS: During the study period 3,123 surgical procedures were performed. In 2005 and 2006, gastric banding (GB) was the operation performed most frequently, followed by the Roux-en-Y gastric bypass (RYGBP). In 2007, a RYGBP was carried out in 42.1% of all bariatric procedures. Among all patients, 74.4% were female. The mean BMI ranged from 48.5 kg/m(2) in 2005 to 48.0 kg/m(2) in 2007. Follow-up data after 12 months were available for 63.8% of the patients operated in 2005 and 2006. The mortality was 0.1% (30 days) and 0.16% (overall). CONCLUSION: As indicated by the worldwide trend, there is an ongoing change from GB to sleeve gastrectomy (SG) and malabsorptive procedures. The BMI of German bariatric surgical patients is substantially higher than that of patients from most other countries. There were no differences in overall outcomes during follow-up as compared to published studies.

Background and Aims: Patients with non-alcoholic steatohepatitis (NASH) have increased intestinal permeability and small intestine bacterial overgrowth. We aimed to test the hypothesis that endotoxaemia is associated with fatty liver in the general population and to study dietary factors associated with endotoxaemia. Methods: Community adult subjects were randomly selected from the Hong Kong Government’s census database and underwent proton-magnetic resonance spectroscopy and transient elastography to assess hepatic steatosis and fibrosis, respectively. Intrahepatic triglyceride content (IHTG) of 5% was the cutoff to define fatty liver. Endotoxaemia was assessed using the Limulus Amebocyte Lysate, lipopolysaccharide-binding protein (LBP) and EndoCab immunoglobulin G (IgG) assays. Dietary pattern was recorded by a 7-day food-frequency questionnaire. Results: 920 subjects were included (42% male, age 48±11, 23% body mass index ≥25kg/m and 5% diabetes). 263 (29%) had fatty liver; 60 (7%) had raised serum cytokeratin-18 fragment level (CK-18) suggestive of NASH; 27 of 887 (3%) subjects with reliable liver stiffness measurement had advanced fibrosis or cirrhosis. Compared with those without fatty liver, subjects with fatty liver had higher LBP (13.4±3.2mg/ml vs 11.4±2.7mg/ml; P < 0.001) and EndoCab IgG (228±247 GMU/ml vs 188±137 GMU/ml; P = 0.013) levels. Endotoxin markers also correlated positively with aminotransferases, IHTG, CK-18, insulin resistance and dyslipidaemia. Endotoxaemia was not associated with increased liver stiffness. Fetuin-A, the ligand linking fatty acid and Toll-like receptor 4, correlated with IHTG, insulin resistance and dyslipidaemia but did not have consistent association with endotoxaemia markers. Although total energy consumption and individual macronutrients were not associated with endotoxaemia, current drinkers (median alcohol consumption 20g/week [interquartile range 10–70 g]) had lower endotoxin, EndoCab IgG and fetuin-A levels than non-drinkers. Conclusions: Endotoxaemia is associated with fatty liver and possibly NASH in the general population. People with modest alcohol consumption have lower serum endotoxin. This may partly explain the lower risk of fatty liver and NASH in modest drinkers in previous observational studies. This study was supported by a grant from the Health and Medical Research Fund sponsored by the Hong Kong SAR Government [Ref CUHK-11120621]. P0981 ADAPTATION OF HEPATIC MITOCHONDRIAL FUNCTION IN OBESE HUMANS WITH OR WITHOUT NON-ALCOHOLIC STEATOHEPATITIS C. Koliaki, J. Szendroedi, K. Kaul, T. Jelenik, P. Nowotny, F. Jankowiak, C. Herder, M. Carstensen, M. Krausch, W. Trudo Knoefel, M. Schlensak, M. Roden. Institute for Clinical Diabetology, German Diabetes Center, Leibniz Center for Diabetes Research, Heinrich Heine University, Dusseldorf, Germany; German Center for Diabetes Research (DZD e.V.), Dusseldorf, Germany; Department of Endocrinology and Diabetology, Heinrich Heine University, Dusseldorf, Germany; Institute of Pathology, Heinrich Heine University, Dusseldorf, Germany; Department of General, Visceral and Pediatric Surgery, Heinrich Heine University, Dusseldorf, Germany; General Surgery Department, St. Martinus Hospital, Dusseldorf, Germany, Dusseldorf, Germany E-mail: ckoliaki@yahoo.com