Cholesterol absorption decreases after Roux-en-Y gastric bypass but not after gastric banding

Short-term effects of gastric bypass versus sleeve gastrectomy on high LDL cholesterol: The BASALTO randomized clinical trial

BACKGROUND

There has been a substantial increase in the use of laparoscopic sleeve gastrectomy (SG) to treat morbid obesity despite observational evidence demonstrating the superiority of Roux-en-Y gastric bypass (RYGB) for reducing low-density lipoprotein (LDL) cholesterol. The main aim was to ascertain whether high LDL cholesterol levels should be considered when selecting the most appropriate surgical procedure for each patient (RYGB or SG).

METHODS

In this single-center, randomized clinical trial using intention-to-treat analysis, 38 patients with severe obesity and elevated levels of LDL cholesterol were randomly assigned to undergo RYGB or SG. The primary outcome was LDL cholesterol remission at 12 months, defined as LDL cholesterol < 3.36 nmol/l without lipid-lowering medications. Secondary outcomes included changes in weight, other comorbidities, qualitative lipoprotein traits, cholesterol esters, glycoproteins, cholesterol absorption and synthesis metabolites and complications.

RESULTS

Intention-to-treat analysis revealed that LDL cholesterol remission occurred in 66.6% of RYGB patients compared to 27.8% of SG patients (p = 0.019). Among patients completing follow-up, RYGB demonstrated superior remission (80.0% vs. 29.4%, p = 0.005). Exclusive benefits of RYGB included a reduction in large, medium, and small LDL particles. Cholesterol absorption markers showed differential behavior after both techniques: campesterol (Δ -15.2 µg/mg, 95% CI -30.2 to -0.1) decreased after RYGB, and sitosterol (Δ 21.1 µg/mg, 95% CI 0.9 to 41.2), cholestanol (Δ 30.6 µg/mg, 95% CI 14.8 to 57.9) and campesterol (Δ 18.4 µg/mg, 95% CI 4.4 to 32.3) increased after SG. No differences in weight loss, cholesterol esters, glycoproteins, cholesterol synthesis metabolites or postoperative complications were observed between techniques.

CONCLUSION

In conclusion, RYGB is superior to SG in terms of short-term of high LDL cholesterol remission. Furthermore, RYGB also led to a greater improvement in lipoprotein parameters that confer an atherogenic profile. Therefore, the presence of elevated levels of LDL cholesterol should be considered when determining the optimal bariatric surgery procedure for each patient.

TRIAL REGISTRATION

Clinicaltrials.gov number, NCT03975478).

Systematic Review and Meta-analysis of the Effects of Laparoscopic Roux-en-Y Gastric Bypass and Laparoscopic Sleeve Gastrectomy on Dyslipidemia

The aim of this meta-analysis was to compare the effects of LRYGB and LSG on dyslipidemia. Studies comparing the effects of LRYGB and LSG on dyslipidemia with follow-up of 12 months or more were included. Twenty-four studies comprising seven RCTs and 17 comparative observational studies were included. Meta-analysis of RCTs (n=487) showed that improvement/resolution of dyslipidemia was better after LRYGB (68.5%, n=161/235) compared to LSG (48.4%, n=122/252). Patients undergoing LRYGB were more than twice as likely to experience improvement/resolution in dyslipidemia compared to those undergoing LSG (OR 2.28, 95% CI 1.21-4.29, p=0.010). Both LRGYB and LSG appears effective in improving dyslipidemia at >12 months after surgery; however, this improvement is more than twice higher after LRYGB compared to LSG.

Single-anastomosis duodeno-ileal bypass with sleeve gastrectomy improves lipid and glucose homeostasis in ob/ob mice

OBJECTIVE

The objective of this study was to compare the general and metabolic impact of single-anastomosis duodeno-ileal bypass with sleeve gastrectomy (SADI-S) with Roux-en-Y gastric bypass (RYGB) in an obese (ob/ob) mouse model.

METHODS

10-week-old male ob/ob mice underwent either SADI-S, RYGB, or laparotomy surgery (Sham group). General and metabolic parameters were assessed during a 5-week period thereafter.

RESULTS

SADI-S induced a deeper weight loss ([mean ± SEM] -41.2% ± 3.3%) than RYGB (-5.6% ± 3.5%, p < 0.001) compared with the Sham group (+6.3% ± 1.0%, p < 0.05). A significant food restriction was observed after SADI-S only (-31%, 117.4 ± 10.3 g vs. 170.2 ± 5.2 g of food at day 35 in Sham group mice, p < 0.001). Random-fed glycemia and glucose tolerance were more improved after SADI-S than RYGB. SADI-S decreased plasma cholesterol concentration by 60% (0.49 ± 0.04 g/L vs. 1.40 ± 0.10 g/L in the Sham group at day 35, p < 0.01), significantly more than RYGB (1.04 ± 0.14 g/L, p = 0.018). Plasma sitosterol/cholesterol and campesterol/cholesterol ratios were decreased after SADI-S, suggesting a reduced intestinal cholesterol absorption. SADI-S increased exogenous plasma cholesterol-D7 clearance and fecal elimination, also indicating an increased plasma cholesterol excretion. Studying a pair-fed group demonstrated that calorie restriction alone did not explain the beneficial impact of SADI-S.

CONCLUSIONS

SADI-S is associated with a greater improvement in lipid and glucose homeostasis than RYGB in ob/ob mice.

Roux-en-Y gastric bypass induces hepatic transcriptomic signatures and plasma metabolite changes indicative of improved cholesterol homeostasis

BACKGROUND & AIMS

Roux-en-Y gastric bypass (RYGB), the most effective surgical procedure for weight loss, decreases obesity and ameliorates comorbidities, such as non-alcoholic fatty liver (NAFLD) and cardiovascular (CVD) diseases. Cholesterol is a major CVD risk factor and modulator of NAFLD development, and the liver tightly controls its metabolism. How RYGB surgery modulates systemic and hepatic cholesterol metabolism is still unclear.

METHODS

We studied the hepatic transcriptome of 26 patients with obesity but not diabetes before and 1 year after undergoing RYGB. In parallel, we measured quantitative changes in plasma cholesterol metabolites and bile acids (BAs).

RESULTS

RYGB surgery improved systemic cholesterol metabolism and increased plasma total and primary BA levels. Transcriptomic analysis revealed specific alterations in the liver after RYGB, with the downregulation of a module of genes implicated in inflammation and the upregulation of three modules, one associated with BA metabolism. A dedicated analysis of hepatic genes related to cholesterol homeostasis pointed towards increased biliary cholesterol elimination after RYGB, associated with enhancement of the alternate, but not the classical, BA synthesis pathway. In parallel, alterations in the expression of genes involved in cholesterol uptake and intracellular trafficking indicate improved hepatic free cholesterol handling. Finally, RYGB decreased plasma markers of cholesterol synthesis, which correlated with an improvement in liver disease status after surgery.

CONCLUSIONS

Our results identify specific regulatory effects of RYGB on inflammation and cholesterol metabolism. RYGB alters the hepatic transcriptome signature, likely improving liver cholesterol homeostasis. These gene regulatory effects are reflected by systemic post-surgery changes of cholesterol-related metabolites, corroborating the beneficial effects of RYGB on both hepatic and systemic cholesterol homeostasis.

IMPACT AND IMPLICATIONS

Roux-en-Y gastric bypass (RYGB) is a widely used bariatric surgery procedure with proven efficacy in body weight management, combatting cardiovascular disease (CVD) and non-alcoholic fatty liver disease (NAFLD). RYGB exerts many beneficial metabolic effects, by lowering plasma cholesterol and improving atherogenic dyslipidemia. Using a cohort of patients undergoing RYGB, studied before and 1 year after surgery, we analyzed how RYGB modulates hepatic and systemic cholesterol and bile acid metabolism. The results of our study provide important insights on the regulation of cholesterol homeostasis after RYGB and open avenues that could guide future monitoring and treatment strategies targeting CVD and NAFLD in obesity.

Impaired Plakophilin-2 in obesity breaks cell cycle dynamics to breed adipocyte senescence

Plakophilin-2 (PKP2) is a key component of desmosomes, which, when defective, is known to promote the fibro-fatty infiltration of heart muscle. Less attention has been given to its role in adipose tissue. We report here that levels of PKP2 steadily increase during fat cell differentiation, and are compromised if adipocytes are exposed to a pro-inflammatory milieu. Accordingly, expression of PKP2 in subcutaneous adipose tissue diminishes in patients with obesity, and normalizes upon mild-to-intense weight loss. We further show defective PKP2 in adipocytes to break cell cycle dynamics and yield premature senescence, a key rheostat for stress-induced adipose tissue dysfunction. Conversely, restoring PKP2 in inflamed adipocytes rewires E2F signaling towards the re-activation of cell cycle and decreased senescence. Our findings connect the expression of PKP2 in fat cells to the physiopathology of obesity, as well as uncover a previously unknown defect in cell cycle and adipocyte senescence due to impaired PKP2.

Cross-tissue omics analysis discovers ten adipose genes encoding secreted proteins in obesity-related non-alcoholic fatty liver disease

BACKGROUND

Non-alcoholic fatty liver disease (NAFLD) is a fast-growing, underdiagnosed, epidemic. We hypothesise that obesity-related inflammation compromises adipose tissue functions, preventing efficient fat storage, and thus driving ectopic fat accumulation into the liver.

METHODS

To identify adipose-based mechanisms and potential serum biomarker candidates (SBCs) for NAFLD, we utilise dual-tissue RNA-sequencing (RNA-seq) data in adipose tissue and liver, paired with histology-based NAFLD diagnosis, from the same individuals in a cohort of obese individuals. We first scan for genes that are differentially expressed (DE) for NAFLD in obese individuals' subcutaneous adipose tissue but not in their liver; encode proteins secreted to serum; and show preferential adipose expression. Then the identified genes are filtered to key adipose-origin NAFLD genes by best subset analysis, knockdown experiments during human preadipocyte differentiation, recombinant protein treatment experiments in human liver HepG2 cells, and genetic analysis.

FINDINGS

We discover a set of genes, including 10 SBCs, that may modulate NAFLD pathogenesis by impacting adipose tissue function. Based on best subset analysis, we further follow-up on two SBCs CCDC80 and SOD3 by knockdown in human preadipocytes and subsequent differentiation experiments, which show that they modulate crucial adipogenesis genes, LPL, SREBPF1, and LEP. We also show that treatment of the liver HepG2 cells with the CCDC80 and SOD3 recombinant proteins impacts genes related to steatosis and lipid processing, including PPARA, NFE2L2, and RNF128. Finally, utilizing the adipose NAFLD DE gene cis-regulatory variants associated with serum triglycerides (TGs) in extensive genome-wide association studies (GWASs), we demonstrate a unidirectional effect of serum TGs on NAFLD with Mendelian Randomization (MR) analysis. We also demonstrate that a single SNP regulating one of the SBC genes, rs2845885, produces a significant MR result by itself. This supports the conclusion that genetically regulated adipose expression of the NAFLD DE genes may contribute to NAFLD through changes in serum TG levels.

INTERPRETATION

Our results from the dual-tissue transcriptomics screening improve the understanding of obesity-related NAFLD by providing a targeted set of 10 adipose tissue-active genes as new serum biomarker candidates for the currently grossly underdiagnosed fatty liver disease.

FUNDING

The work was supported by NIH grants R01HG010505 and R01DK132775. The Genotype-Tissue Expression (GTEx) Project was supported by the Common Fund of the Office of the Director of the National Institutes of Health, and by NCI, NHGRI, NHLBI, NIDA, NIMH, and NINDS. The KOBS study (J. P.) was supported by the Finnish Diabetes Research Foundation, Kuopio University Hospital Project grant (EVO/VTR grants 2005-2019), and the Academy of Finland grant (Contract no. 138006). This study was funded by the European Research Council under the European Union's Horizon 2020 research and innovation program (Grant No. 802825 to M. U. K.). K. H. P. was funded by the Academy of Finland (grant numbers 272376, 266286, 314383, and 335443), the Finnish Medical Foundation, Gyllenberg Foundation, Novo Nordisk Foundation (grant numbers NNF10OC1013354, NNF17OC0027232, and NNF20OC0060547), Finnish Diabetes Research Foundation, Finnish Foundation for Cardiovascular Research, University of Helsinki, and Helsinki University Hospital and Government Research Funds. I. S. was funded by the Instrumentarium Science Foundation. Personal grants to U. T. A. were received from the Matti and Vappu Maukonen Foundation, Ella och Georg Ehrnrooths Stiftelse and the Finnish Foundation for Cardiovascular Research.

Indole-3-Propionic Acid, a Gut-Derived Tryptophan Metabolite, Associates with Hepatic Fibrosis

Background and Aims: Gut microbiota-derived metabolites play a vital role in maintenance of human health and progression of disorders, including obesity and type 2 diabetes (T2D). Indole-3-propionic acid (IPA), a gut-derived tryptophan metabolite, has been recently shown to be lower in individuals with obesity and T2D. IPA’s beneficial effect on liver health has been also explored in rodent and cell models. In this study, we investigated the association of IPA with human liver histology and transcriptomics, and the potential of IPA to reduce hepatic stellate cell activation in vitro. Methods: A total of 233 subjects (72% women; age 48.3 ± 9.3 years; BMI 43.1 ± 5.4 kg/m²) undergoing bariatric surgery with detailed liver histology were included. Circulating IPA levels were measured using LC-MS and liver transcriptomics with total RNA-sequencing. LX-2 cells were used to study hepatoprotective effect of IPA in cells activated by TGF-β1. Results: Circulating IPA levels were found to be lower in individuals with liver fibrosis compared to those without fibrosis (p = 0.039 for all participants; p = 0.013 for 153 individuals without T2D). Accordingly, levels of circulating IPA associated with expression of 278 liver transcripts (p < 0.01) that were enriched for the genes regulating hepatic stellate cells (HSCs) activation and hepatic fibrosis signaling. Our results suggest that IPA may have hepatoprotective potential because it is able to reduce cell adhesion, cell migration and mRNA gene expression of classical markers of HSCs activation in LX-2 cells (all p < 0.05). Conclusion: The association of circulating IPA with liver fibrosis and the ability of IPA to reduce activation of LX-2 cells suggests that IPA may have a therapeutic potential. Further molecular studies are needed to investigate the mechanisms how IPA can ameliorate hepatic fibrosis.

Improvement of Lipid Profile after One-Anastomosis Gastric Bypass Compared to Sleeve Gastrectomy

Fewer studies compared the improvement of plasma lipid levels after different types of surgery, in particular compared to one-anastomosis gastric bypass (OAGB). The aim of our study was to investigate how laparoscopic sleeve gastrectomy (LSG) and OAGB impact on weight loss and lipid profile 18 months after surgery, in patients with severe obesity. Forty-six patients treated with OAGB were matched to eighty-eight patients submitted to LSG. Weight loss after OAGB (33.2%) was more evident than after LSG (29.6%) (p = 0.024). The difference in the prevalence of dyslipidemia showed a statistically significant reduction only after OAGB (61% versus 22%, p < 0.001). After adjustment for delta body mass index (BMI), age and sex, we demonstrated a statistically significant decrease of the differences between the changes before and after (delta Δ) the two surgery procedures: Δ total cholesterol values (p < 0.001), Δ low density lipoprotein-cholesterol values (p < 0.001) and Δ triglycerides values (p = 0.007). Patients with severe obesity undergoing to OAGB presented a better improvement of lipid plasma values than LSG patients. The reduction of lipid plasma levels was independent of the significant decrease of BMI after surgery, of age and of sex.

Identification of TBX15 as an adipose master trans regulator of abdominal obesity genes

Background

Obesity predisposes individuals to multiple cardiometabolic disorders, including type 2 diabetes (T2D). As body mass index (BMI) cannot reliably differentiate fat from lean mass, the metabolically detrimental abdominal obesity has been estimated using waist-hip ratio (WHR). Waist-hip ratio adjusted for body mass index (WHRadjBMI) in turn is a well-established sex-specific marker for abdominal fat and adiposity, and a predictor of adverse metabolic outcomes, such as T2D. However, the underlying genes and regulatory mechanisms orchestrating the sex differences in obesity and body fat distribution in humans are not well understood.

Methods

We searched for genetic master regulators of WHRadjBMI by employing integrative genomics approaches on human subcutaneous adipose RNA sequencing (RNA-seq) data (n ~ 1400) and WHRadjBMI GWAS data (n ~ 700,000) from the WHRadjBMI GWAS cohorts and the UK Biobank (UKB), using co-expression network, transcriptome-wide association study (TWAS), and polygenic risk score (PRS) approaches. Finally, we functionally verified our genomic results using gene knockdown experiments in a human primary cell type that is critical for adipose tissue function.

Results

Here, we identified an adipose gene co-expression network that contains 35 obesity GWAS genes and explains a significant amount of polygenic risk for abdominal obesity and T2D in the UKB (n = 392,551) in a sex-dependent way. We showed that this network is preserved in the adipose tissue data from the Finnish Kuopio Obesity Study and Mexican Obesity Study. The network is controlled by a novel adipose master transcription factor (TF), TBX15, a WHRadjBMI GWAS gene that regulates the network in trans. Knockdown of TBX15 in human primary preadipocytes resulted in changes in expression of 130 network genes, including the key adipose TFs, PPARG and KLF15, which were significantly impacted (FDR < 0.05), thus functionally verifying the trans regulatory effect of TBX15 on the WHRadjBMI co-expression network.

Conclusions

Our study discovers a novel key function for the TBX15 TF in trans regulating an adipose co-expression network of 347 adipose, mitochondrial, and metabolically important genes, including PPARG, KLF15, PPARA, ADIPOQ, and 35 obesity GWAS genes. Thus, based on our converging genomic, transcriptional, and functional evidence, we interpret the role of TBX15 to be a main transcriptional regulator in the adipose tissue and discover its importance in human abdominal obesity.

Supplementary Information

The online version contains supplementary material available at 10.1186/s13073-021-00939-2.

The Effect of Laparoscopic Sleeve Gastrectomy and Gastric Bypass Surgery on Non-Alcoholic Steatohepatitis in Iranian Patients with Obesity

BACKGROUND Non-alcoholic steatohepatitis (NASH) is a serious comorbidity in patients with obesity and because of the high risk of cirrhosis and the extreme mortality rate of NASH, approaching effective treatment methods, and improvements are crucial. Following few studies comparing the impact of laparoscopic gastric bypass (LGB) and laparoscopic sleeve gastrectomy (LSG) surgery on NASH, our study was conducted to assess the effect of these two surgical methods separately in patients with NASH through ultrasonography, and concurrently, on other factors such as lipid profiles and blood pressure to reduce the complications of complex obesity surgeries on patients and also provide a solution to prevent NASH-related cirrhosis. METHODS This study was performed at Imam Khomeini Hospital Complex; Vali-e-Asr Hospital affiliated to Tehran University of Medical Sciences.All patients with obesity who had undergone bariatric surgery at Vali-e-Asr Hospital during 2017 and 2018 were included in this prospective cohort study. Weight, body mass index (BMI), blood pressure, Alanine transaminase(ALT), Aspartate transaminase(AST),lipid profile and Fasting blood sugar(FBS)were evaluated before and one year after surgery. The patients underwent an ultrasound examination before surgery to determine the fatty liver grade. The type of operation (sleeve or bypass) was governed by the patient him/herself after receiving thorough clarifications about the available methods, their complications, and expected outcomes. In addition, by the separation of fatty liver grading with ultrasound modality, the correlation between ultrasound grading, laboratory results, and the rate of weight loss in patients who undergone both sleeve and bypass surgeries were evaluated and compared during a one-year follow-up. RESULTS In this study, 44 patients were included. 22 patients underwent laparoscopic sleeve gastrectomy (LSG), and 22 patients underwent laparoscopic gastric bypass (LGB) surgery. The mean age of the patients was 40.45 ± 12.01 years. 35 patients (79.5%) were women, and 9 patients (20.5%) were men. Most patients (81.8%) had grade I and II in terms of preoperative liver ultrasonography results. Bariatric surgery (LSG and LGB) greatly enhanced NASH's hepatic status in liver ultrasonography. Since the liver status of patients with preoperative ultrasonography was not significantly different between the two groups, there was no substantial distinction among the two groups in this regard, postoperatively. Weight and BMI, lipid profile, liver enzymes, FBS, and mean arterial blood pressure (MAP) were significantly reduced individually in both groups and all patients one year after surgery. None of the postoperative variables and their modifications had a prominent difference between the two groups except for High-density lipoprotein(HDL)level after surgery. The postoperative HDL was considerably higher in the LGB group (p = 0.014). However, the changes in HDL were not statistically different between both groups. The levels of AST, ALT, total cholesterol, LDL, and FBS were associated with the NASH grade. CONCLUSION Both types of LSG and LGB bariatric surgeries have been shown to significantly reduce BMI and improve lipid profiles, liver enzymes, and blood glucose levels in patients one year after surgery. The NASH status was also ameliorated considerably. The two types of surgery were not remarkably different in these modifications. Besides, there was a significant correlation between AST, ALT, total cholesterol, LDL, and FBS levels with the NASH grade.

Pregnancy and lactation after Roux-en-Y gastric bypass worsen nonalcoholic fatty liver disease in obese rats and lead to differential programming of hepatic de novo lipogenesis in offspring

Maternal obesity increases the risk of nonalcoholic fatty liver disease (NAFLD) in offspring. The Roux-en-Y gastric bypass (RYBG) is effective for achieving weight loss and ameliorates NAFLD. To determine whether these benefits are maintained after pregnancy and/or lactation, and whether they modulate hepatic morphofunction in the next generation, we evaluated hepatic lipid metabolism in Western diet (WD)-obese female rats that underwent RYGB and in their F1 offspring at adulthood. Female Wistar rats consumed a WD from 21 to 130 days of age, before being submitted to RYGB (WD-RYGB-F0) or SHAM (WD-SHAM-F0) operations. After 5 weeks, these females were mated with control male breeders, and the male and female F1 offspring were identified as WD-RYGB-F1 and WD-SHAM-F1. WD-RYGB-F0 dams exhibited lower serum lipids levels, but severe hepatic steatosis and pathological features of advanced liver injury. The hepatic proteins involved in lipogenesis were reduced in WD-RYGB-F0, as were the genes related to β-oxidation and bile acids (BAs). Although the female and male WD-RYGB-F1 groups did not exhibit hepatic steatosis, the livers of female WD-RYGB-F1 demonstrated higher amounts of lipogenic genes and proteins, while male WD-RYGB-F1 presented a similar downregulation of lipogenic factors to that seen in WD-RYGB-F0 dams. In contrast, maternal and offspring groups of both sexes displayed reductions in the expressions of genes involved in BAs physiology and gluconeogenesis. As such, RYGB aggravates NAFLD after pregnancy and lactation and induces a gender-dependent differential expression of the hepatic lipogenesis pathway in offspring, indicating that female WD-RYGB-F1 may be an increased risk of developing NAFLD.

Differential Mitochondrial Gene Expression in Adipose Tissue Following Weight Loss Induced by Diet or Bariatric Surgery

CONTEXT

Mitochondria are essential for cellular energy homeostasis, yet their role in subcutaneous adipose tissue (SAT) during different types of weight-loss interventions remains unknown.

OBJECTIVE

To investigate how SAT mitochondria change following diet-induced and bariatric surgery-induced weight-loss interventions in 4 independent weight-loss studies.

METHODS

The DiOGenes study is a European multicenter dietary intervention with an 8-week low caloric diet (LCD; 800 kcal/d; n = 261) and 6-month weight-maintenance (n = 121) period. The Kuopio Obesity Surgery study (KOBS) is a Roux-en-Y gastric bypass (RYGB) surgery study (n = 172) with a 1-year follow-up. We associated weight-loss percentage with global and 2210 mitochondria-related RNA transcripts in linear regression analysis adjusted for age and sex. We repeated these analyses in 2 studies. The Finnish CRYO study has a 6-week LCD (800-1000 kcal/d; n = 19) and a 10.5-month follow-up. The Swedish DEOSH study is a RYGB surgery study with a 2-year (n = 49) and 5-year (n = 37) follow-up.

RESULTS

Diet-induced weight loss led to a significant transcriptional downregulation of oxidative phosphorylation (DiOGenes; ingenuity pathway analysis [IPA] z-scores: -8.7 following LCD, -4.4 following weight maintenance; CRYO: IPA z-score: -5.6, all P < 0.001), while upregulation followed surgery-induced weight loss (KOBS: IPA z-score: 1.8, P < 0.001; in DEOSH: IPA z-scores: 4.0 following 2 years, 0.0 following 5 years). We confirmed an upregulated oxidative phosphorylation at the proteomics level following surgery (IPA z-score: 3.2, P < 0.001).

CONCLUSIONS

Differentially regulated SAT mitochondria-related gene expressions suggest qualitative alterations between weight-loss interventions, providing insights into the potential molecular mechanistic targets for weight-loss success.

Serum aromatic and branched-chain amino acids associated with NASH demonstrate divergent associations with serum lipids

BACKGROUND & AIMS

Non-alcoholic fatty liver disease (NAFLD) has been associated with multiple metabolic abnormalities. By applying a non-targeted metabolomics approach, we aimed at investigating whether serum metabolite profile that associates with NAFLD would differ in its association with NAFLD-related metabolic risk factors.

METHODS & RESULTS

A total of 233 subjects (mean ± SD: 48.3 ± 9.3 years old; BMI: 43.1 ± 5.4 kg/m² ; 64 male) undergoing bariatric surgery were studied. Of these participants, 164 with liver histology could be classified as normal liver (n = 79), simple steatosis (SS, n = 40) or non-alcoholic steatohepatitis (NASH, n = 45). Among the identified fasting serum metabolites with higher levels in those with NASH when compared to those with normal phenotype were the aromatic amino acids (AAAs: tryptophan, tyrosine and phenylalanine), the branched-chain amino acids (BCAAs: leucine and isoleucine), a phosphatidylcholine (PC(16:0/16:1)) and uridine (all FDRp < 0.05). Only tryptophan was significantly higher in those with NASH compared to those with SS (FDRp < 0.05). Only the AAAs tryptophan and tyrosine correlated positively with serum total and LDL cholesterol (FDRp < 0.1), and accordingly, with liver LDLR at mRNA expression level. In addition, tryptophan was the single AA associated with liver DNA methylation of CpG sites known to be differentially methylated in those with NASH.

CONCLUSIONS

We found that serum levels of the NASH-related AAAs and BCAAs demonstrate divergent associations with serum lipids. The specific correlation of tryptophan with LDL-c may result from the molecular events affecting LDLR mRNA expression and NASH-associated methylation of genes in the liver.

Visual Analysis of Biomarkers Reveals Differences in Lipid Profiles and Liver Enzymes before and after Gastric Sleeve and Bypass

INTRODUCTION

Bariatric surgery results in both intentional and unintentional metabolic changes. In a high-volume bariatric center, extensive laboratory panels are used to monitor these changes pre- and postoperatively. Consecutive measurements of relevant biochemical markers allow exploration of the health state of bariatric patients and comparison of different patient groups.

OBJECTIVE

The objective of this study is to compare biomarker distributions over time between 2 common bariatric procedures, i.e., sleeve gastrectomy (SG) and gastric bypass (RYGB), using visual analytics.

METHODS

Both pre- and postsurgical (6, 12, and 24 months) data of all patients who underwent primary bariatric surgery were collected retrospectively. The distribution and evolution of different biochemical markers were compared before and after surgery using asymmetric beanplots in order to evaluate the effect of primary SG and RYGB. A beanplot is an alternative to the boxplot that allows an easy and thorough visual comparison of univariate data.

RESULTS

In total, 1,237 patients (659 SG and 578 RYGB) were included. The sleeve and bypass groups were comparable in terms of age and the prevalence of comorbidities. The mean presurgical BMI and the percentage of males were higher in the sleeve group. The effect of surgery on lowering of glycated hemoglobin was similar for both surgery types. After RYGB surgery, the decrease in the cholesterol concentration was larger than after SG. The enzymatic activity of aspartate aminotransferase, alanine aminotransferase, and alkaline phosphate in sleeve patients was higher presurgically but lower postsurgically compared to bypass values.

CONCLUSIONS

Beanplots allow intuitive visualization of population distributions. Analysis of this large population-based data set using beanplots suggests comparable efficacies of both types of surgery in reducing diabetes. RYGB surgery reduced dyslipidemia more effectively than SG. The trend toward a larger decrease in liver enzyme activities following SG is a subject for further investigation.

Protein Phosphatase 1 Regulatory Subunit 3B Genotype at rs4240624 Has a Major Effect on Gallbladder Bile Composition

The protein phosphatase 1 regulatory subunit 3B (PPP1R3B) gene is a target of farnesoid X receptor (FXR), which is a major regulator of bile acid metabolism. Both PPP1R3B and FXR have been suggested to take part in glycogen metabolism, which may explain the association of PPP1R3B gene variants with altered hepatic computed tomography attenuation. We analyzed the effect of PPP1R3B rs4240624 variant on bile acid composition in individuals with obesity. The study cohort consisted of 242 individuals from the Kuopio Obesity Surgery Study (73 men, 169 women, age 47.6 ± 9.0 years, body mass index 43.2 ± 5.4 kg/m²) with PPP1R3B genotype and liver RNA sequencing (RNA-seq) data available. Fasting plasma and gallbladder bile samples were collected from 50 individuals. Bile acids in plasma did not differ based on the PPP1R3B rs4240624 genotype. However, the concentration of total bile acids (109 ± 55 vs. 35 ± 19 mM; P = 1.0 × 10^-5) and all individual bile acids (also 7α-hydroxy-4-cholesten-3-one [C4]) measured from bile were significantly lower in those with the AG genotype compared to those with the AA genotype. In addition, total cholesterol (P = 0.011) and phospholipid (P = 0.001) levels were lower in individuals with the AG genotype, but cholesterol saturation index did not differ, indicating that the decrease in cholesterol and phospholipid levels was secondary to the change in bile acids. Liver RNA-seq data demonstrated that expression of PPP1R3B, tankyrase (TNKS), Homo sapiens chromosome 8 clone RP11-10A14.5 (AC022784.1 [LOC157273]), Homo sapiens chromosome 8 clone RP11-375N15.1 (AC021242.1), and Homo sapiens chromosome 8, clone RP11-10A14 (AC022784.6) associated with the PPP1R3B genotype. In addition, genes enriched in transmembrane transport and phospholipid binding pathways were associated with the genotype. Conclusion: The rs4240624 variant in PPP1R3B has a major effect on the composition of gallbladder bile. Other transcripts in the same loci may be important mediators of the variant effect.

Additional Metabolic Effects of Bariatric Surgery in Patients with a Poor Mid-Term Weight Loss Response: A 5-Year Follow-Up Study

To ascertain the 5-year metabolic effects of bariatric surgery in poor weight loss (WL) responders and establish associated factors. Methods: Retrospective analysis of a non-randomised prospective cohort of bariatric surgery patients completing a 5-year follow-up. Mid-term poor WL was considered when 5-year excess weight loss was <50%. Results: Forty-three (20.3%) of the 212 included patients were mid-term poor WL responders. They showed an improvement in all metabolic markers at 2 years, except for total cholesterol. This improvement with respect to baseline was maintained at 5 years for plasma glucose, HbA1c, HOMA, HDL and diastolic blood pressure; however, LDL cholesterol, triglycerides and systolic blood pressure were similar to presurgical values. Comorbidity remission rates were comparable to those obtained in the good WL group except for hypercholesterolaemia (45.8% vs. poor WL, p = 0.005). On multivariate analysis, lower baseline HDL cholesterol levels, advanced age and lower preoperative weight loss were independently associated with poor mid-term WL. Conclusions: Although that 1 in 5 patients presented suboptimal WL 5 years after bariatric surgery, other important metabolic benefits were maintained.

Bariatric surgery and LDL cholesterol (BASALTO) trial study protocol: randomised controlled study evaluating the effect of gastric bypass versus sleeve gastrectomy on high LDL cholesterol

INTRODUCTION

Observational studies have shown gastric bypass to be superior to sleeve gastrectomy in terms of low-density lipoprotein (LDL) cholesterol improvement. If these results are confirmed in randomised controlled trials, presurgical LDL cholesterol status could be a relevant factor in surgical procedure election. Furthermore, it is also necessary to establish the mechanisms by which LDL cholesterol improves after surgery and whether qualitative and quantitative changes occur in the different lipoprotein subclasses. The first objective is to ascertain whether high LDL cholesterol levels before surgery can be considered an additional factor when selecting the most appropriate surgical procedure for each patient (gastric bypass or sleeve gastrectomy). Hence, the 1-year remission rates of high LDL cholesterol after gastric bypass and sleeve gastrectomy in patients with morbid obesity will be compared. Secondary objectives were (1) to compare changes in other lipoproteins and LDL composition and (2) to study the pathophysiologic mechanisms related to LDL cholesterol remission.

METHODS AND ANALYSIS

A randomised clinical trial, with intention-to-treat analysis, will be conducted to compare LDL cholesterol remission between gastric bypass and sleeve gastrectomy, with a 12-month follow-up. Inclusion criteria will be patients between 18 and 60 years of age with body mass index ≥40 kg/m² or ≥35 kg/m² with significant obesity-related comorbidity and high LDL cholesterol levels. Patients will be evaluated preoperatively and at 3, 6 and 12 months after bariatric surgery. Examinations will include routine blood chemistry, anthropometric measurements, food intake recall, physical activity questionnaires and serum samples for lipidomic and lipoprotein characterisation.

ETHICS AND DISSEMINATION

Ethics approval has been granted by the Parc de Salut Mar Ethics Committee (2019/8471/I). The study and its conclusions regarding the primary and secondary objectives will be presented as manuscripts submitted for peer-reviewed journal publication.

TRIAL REGISTRATION NUMBER

NCT03975478.

Disease, Drugs and Dysbiosis: Understanding Microbial Signatures in Metabolic Disease and Medical Interventions

Since the discovery of the potential role for the gut microbiota in health and disease, many studies have gone on to report its impact in various pathologies. These studies have fuelled interest in the microbiome as a potential new target for treating disease Here, we reviewed the key metabolic diseases, obesity, type 2 diabetes and atherosclerosis and the role of the microbiome in their pathogenesis. In particular, we will discuss disease associated microbial dysbiosis; the shift in the microbiome caused by medical interventions and the altered metabolite levels between diseases and interventions. The microbial dysbiosis seen was compared between diseases including Crohn’s disease and ulcerative colitis, non-alcoholic fatty liver disease, liver cirrhosis and neurodegenerative diseases, Alzheimer’s and Parkinson’s. This review highlights the commonalities and differences in dysbiosis of the gut between diseases, along with metabolite levels in metabolic disease vs. the levels reported after an intervention. We identify the need for further analysis using systems biology approaches and discuss the potential need for treatments to consider their impact on the microbiome.

Impact of Metabolic Surgery on Type 2 Diabetes Mellitus, Cardiovascular Risk Factors, and Mortality: A Review

BACKGROUND

The association between obesity and a reduction in life expectancy is well established, and cardiovascular disease is a leading cause of mortality. Bariatric surgery has long been established as the most effective and durable intervention for obesity, and is the only intervention for obesity that consistently improves multiple comorbidities, reduces cardiovascular disease and long-term mortality. The purpose of this review is to describe the impact of metabolic/bariatric surgery on type 2 diabetes mellitus and cardiometabolic parameters, including cardiovascular mortality.

METHODS

A systematic literature search of Pubmed, MEDLINE, and Cochrane Central Register was performed. We included randomized controlled trials, meta-analysis, case-control trials, and cohort studies that contain data on reductions in cardiovascular risk factors and cardiovascular mortality in subjects who underwent metabolic/bariatric surgery from January 1, 2005 to June 1, 2020.

CONCLUSION

There is sufficient evidence from randomized controlled trials that metabolic/bariatric surgery is associated with a significant improvement of all cardiovascular risk factors. Although studies are showing a reduction of macrovascular events and cardiovascular mortality, these findings come from observational studies and should be confirmed in randomized clinical trials.

Metabolic and cardiovascular outcomes of bariatric surgery

PURPOSE OF REVIEW

Bariatric surgery is an effective therapy for morbid obesity that also improves weight-related metabolic parameters and reduces morbidity and mortality. The purpose of this review is to consolidate our current understanding of metabolic, macrovascular and microvascular benefits of bariatric surgery and to provide an update.

RECENT FINDINGS

Early resolution of insulin resistance and type 2 diabetes mellitus (T2DM) varies by type of bariatric surgery and appears to be mediated by changes in secretion of gut hormones, metabolism of bile acids, expression of glucose transporters and the gut microbiome. Dyslipidaemia, atherosclerosis, microvascular complications of obesity and diabetes, systemic and tissue-level inflammation show evidence of regression and hypertension improves significantly after bariatric surgery.

SUMMARY

Bariatric surgery leads to improvements in obesity-related metabolic comorbidities such as dyslipidaemia, HDL functionality, hypertension, T2DM, insulin resistance and inflammation. It slows the atherosclerotic process and reduces cardiovascular and all-cause mortality. Recent data have demonstrated regression of the microvascular complications of obesity and diabetes including the regeneration of small nerve fibres. The magnitude of change in short-term metabolic effects depends on the surgical procedure whilst longer term effects are related to the amount of sustained excess weight loss.

Roux-en-Y Gastric Bypass Is More Effective than Sleeve Gastrectomy in Improving Postprandial Glycaemia and Lipaemia in Non-diabetic Morbidly Obese Patients: a Short-term Follow-up Analysis

PURPOSE

We aimed to compare the effects of Roux-en-Y gastric bypass (RYGB) and sleeve gastrectomy (SG) on postprandial glucose and lipid metabolism in addition to weight loss and fasting metabolic profile, in non-diabetic patients undergoing bariatric surgery.

METHODS

Seventy-one patients were consecutively recruited and studied preoperatively, 3 and 6 months after surgery. Of these, 28 underwent RYGB (7 males, age 38 ± 9 years, BMI 46.9 ± 5.0 kg/m²), and 43 SG (9 males, age 38 ± 9 years, BMI 50.2 ± 7.0 kg/m²). A semi-liquid mixed meal was consumed, and blood samples were taken before, and every 30 min after meal ingestion up to 180 min postprandially, for measurement of glucose, insulin, and lipids. The overall postprandial response was assessed as area under the concentration-time curve (AUC).

RESULTS

Baseline metabolic parameters were similar between RYGB and SG. Both groups experienced comparable weight loss, and a similar improvement in fasting glucose, insulin, and insulin resistance. Total and LDL cholesterol levels were lower at 6 months after RYGB compared to SG, while there was no difference in HDL cholesterol or triglycerides. Glucose AUC was lower after RYGB compared to SG at both 3 (p = 0.008) and 6 months (p = 0.016), without any difference in postprandial insulin response. Triglyceride AUC was also lower in RYGB vs. SG at 3 and 6 months (p ≤ 0.001).

CONCLUSIONS

RYGB is superior to SG in improving postprandial glycaemia and lipaemia and cholesterol profile 6 months postoperatively in non-diabetic, severely obese patients. These findings imply procedure-specific effects, such as the malabsorptive nature of RYGB, and less likely a different incretin postoperative response.

Total liver phosphatidylcholine content associates with non-alcoholic steatohepatitis and glycine N-methyltransferase expression

BACKGROUND & AIMS

Alterations in liver phosphatidylcholine (PC) metabolism have been implicated in the pathogenesis of non-alcoholic fatty liver disease (NAFLD). Although genetic variation in the phosphatidylethanolamine N-methyltransferase (PEMT) enzyme synthesizing PC has been associated with disease, the functional mechanism linking PC metabolism to the pathogenesis of non-alcoholic steatohepatitis (NASH) remains unclear.

METHODS

Serum PC levels and liver PC contents were measured using proton nuclear magnetic resonance (NMR) spectroscopy in 169 obese individuals [age 46.6 ± 10 (mean ± SD) years, BMI 43.3 ± 6 kg/m² , 53 men and 116 women] with histological assessment of NAFLD; 106 of these had a distinct liver phenotype. All subjects were genotyped for PEMT rs7946 and liver mRNA expression of PEMT and glycine N-methyltransferase (GNMT) was analysed.

RESULTS

Liver PC content was lower in those with NASH (P = 1.8 x 10^-6 ) while serum PC levels did not differ between individuals with NASH and normal liver (P = 0.591). Interestingly, serum and liver PC did not correlate (r_s  = -0.047, P = 0.557). Serum PC and serum cholesterol levels correlated strongly (r_s  = 0.866, P = 7.1 x 10^-49 ), while liver PC content did not correlate with serum cholesterol (r_s  = 0.065, P = 0.413). Neither PEMT V175M genotype nor PEMT expression explained the association between liver PC content and NASH. Instead, liver GNMT mRNA expression was decreased in those with NASH (P = 3.8 x 10^-4 ) and correlated with liver PC content (r_s  = 0.265, P = 0.001).

CONCLUSIONS

Decreased liver PC content in individuals with the NASH is independent of PEMT V175M genotype and could be partly linked to decreased GNMT expression.

The Effects of Bariatric Surgery on Islet Function, Insulin Secretion, and Glucose Control

Although bariatric surgery was developed primarily to treat morbid obesity, evidence from the earliest clinical observations to the most recent clinical trials consistently demonstrates that these procedures have substantial effects on glucose metabolism. A large base of research indicates that bariatric surgeries such as Roux-en-Y gastric bypass (RYGB), vertical sleeve gastrectomy (VSG), and biliopancreatic diversion (BPD) improve diabetes in most patients, with effects frequently evident prior to substantial weight reduction. There is now unequivocal evidence from randomized controlled trials that the efficacy of surgery is superior to intensive life-style/medical management. Despite advances in the clinical understanding and application of bariatric surgery, there remains only limited knowledge of the mechanisms by which these procedures confer such large changes to metabolic physiology. The improvement of insulin sensitivity that occurs with weight loss (e.g., the result of diet, illness, physical training) also accompanies bariatric surgery. However, there is evidence to support specific effects of surgery on insulin clearance, hepatic glucose production, and islet function. Understanding the mechanisms by which surgery affects these parameters of glucose regulation has the potential to identify new targets for therapeutic discovery. Studies to distinguish among bariatric surgeries on key parameters of glucose metabolism are limited but would be of considerable value to assist clinicians in selecting specific procedures and investigators in delineating the resulting physiology. This review is based on literature related to factors governing glucose metabolism and insulin secretion after the commonly used RYGB and VSG, and the less frequently used BPD and adjustable gastric banding.

Body weight-dependent and independent improvement in lipid metabolism after Roux-en-Y gastric bypass in ApoE*3Leiden.CETP mice

BACKGROUND/OBJECTIVES

The incidence of obesity and metabolic syndrome (MetS) has rapidly increased worldwide. Roux-en-Y gastric bypass (RYGB) achieves long-term weight loss and improves MetS-associated comorbidities. Using a mouse model with a humanized lipoprotein metabolism, we elucidated whether improvements in lipid and glucose metabolism after RYGB surgery are body weight loss-dependent or not.

SUBJECTS/METHODS

Male ApoE*3Leiden.CETP (ApoE3L.CETP) mice fed Western type diet for 6 weeks underwent RYGB or Sham surgery. Sham groups were either fed ad libitum or were body weight-matched (BWm) to the RYGB mice to discriminate surgical effects from body weight loss-associated effects. Before and after surgery, plasma was collected to assess the metabolic profile, and glucose tolerance and insulin sensitivity were tested. Twenty days after surgery, mice were sacrificed, and liver was collected to assess metabolic, histological and global gene expression changes after surgery.

RESULTS

RYGB induced a marked reduction in body weight, which was also achieved by severe food restriction in BWm mice, and total fat mass compared to Sham ad libitum mice (Sham AL). Total cholesterol, non-high-density lipoprotein cholesterol (non-HDL-C) and ceramide were strongly reduced 20 days after surgery in RYGB compared to BWm mice. Glucose tolerance and insulin sensitivity improved 13 days after surgery similarly in RYGB and BWm mice. Liver histology confirmed lipid reduction in RYGB and BWm mice while the transcriptomics data indicated altered genes expression in lipid metabolism.

CONCLUSIONS

RYGB surgery improves glucose metabolism and greatly ameliorates lipid metabolism in part in a body weight-dependent manner. Given that ApoE3L.CETP mice were extensively studied to describe the MetS, and given that RYGB improved ceramide after surgery, our data confirmed the usefulness of ApoE3L.CETP mice after RYGB in deciphering the metabolic improvements to treat the MetS.

Lipid profile change after bariatric surgeries: laparoscopic gastric plication versus mini gastric bypass

INTRODUCTION

Bariatric surgeries are known to have profound effects on lipid profile. Laparoscopic gastric plication (LGP) has been shown to have a comparable effect on weight loss rather than Roux-en-Y gastric bypass (RYGB) and mini gastric bypass (MGB). But the post-operative effect on lipid profile is not well-compared. We aimed to compare post-operative lipid profile change after LGP and MGB.

METHODS

In a retrospective analysis, we reviewed 91 patients for at least 12 months. Patients were assigned to undergo either LGP (71 patients) or MGB (20 patients). Preoperative and postoperative visits were accomplished and weight, BMI, fasting blood glucose (FBG) and lipid profile including triglyceride (TG), and total cholesterol (TC) levels were repeatedly measured. Follow up rate for the first year was 100%.

RESULTS

LGP significantly decreased both TG and TC levels in each follow up (all p values < .05). The same trends were observed in BMI reduction, total body weight loss percentage, and FBG. When comparing either TC or TG level between LGP and MGB, there was just one statistically significant result in TG reduction at 6 months (p value = .042) while MGB showed more reduction. All other variables in different follow up visits were not significantly different between two techniques.

CONCLUSIONS

LGP would result in lipid profile improvement lasting at least for one year. Lipid-lowering effect seems to be similar between LGP and MGB. This lipid-lowering property and weight reduction might be indicative that LGP is an alternative for RYGB and MGB in selective patients.

Laparoscopic Roux-en-Y gastric bypass surgery influenced pharmacokinetics of several drugs given as a cocktail with the highest impact observed for CYP1A2, CYP2C8 and CYP2E1 substrates

There is a lack of information about the changes in drug pharmacokinetics and cytochrome P450 (CYP) metabolism after bariatric surgery. Here, we investigated the effects of laparoscopic Roux-en-Y gastric bypass (LRYGB) surgery on pharmacokinetics of nine drugs given simultaneously which may reveal changes in the activities of the main CYPs. Eight obese subjects undergoing LRYGB received an oral cocktail containing nine drugs, substrates of various CYPs: melatonin (CYP1A2), nicotine (CYP2A6), bupropion (CYP2B6), repaglinide (CYP2C8), losartan (CYP2C9), omeprazole (CYP2C19/CYP3A4), dextromethorphan (CYP2D6), chlorzoxazone (CYP2E1) and midazolam (CYP3A). The 6-hours pharmacokinetic profiles in serum and urine of each drug or corresponding metabolite as well as their metabolic ratios were compared before surgery with those at a median 1 year later. LRYGB exerted variable effects on the pharmacokinetics of these drugs. The geometric mean AUC_0-6 (90% confidence interval) of melatonin, bupropion, repaglinide, chlorzoxazone and midazolam after LRYGB was 27 (19%-41%), 54 (43%-67%), 44 (29%-66%), 160 (129%-197%) and 74 (62%-90%) of the pre-surgery values, respectively. The pharmacokinetics of losartan, omeprazole and dextromethorphan did not change in response to surgery. Nicotine was not detected in serum, while geometric mean of AUC_0-6 of its metabolite, cotinine, increased by 1.7 times after surgery. There were 3.6- and 1.3-fold increases in the AUC ratios of 6-hydroxymelatonin/melatonin and hydroxybupropion/bupropion, respectively. The cocktail revealed multiple pharmacokinetic changes occurring after LRYGB with the greatest effects observed for CYP1A2, CYP2C8 and CYP2E1 substrates. Future studies should be focused on CYP1A2, CYP2A6, CYP2C8 and CYP2B6 to clarify the changes in activities of these enzymes after LRYGB.

Intestine-Specific Overexpression of LDLR Enhances Cholesterol Excretion and Induces Metabolic Changes in Male Mice

Roux-en-Y gastric bypass (RYGB) surgery is one of the most effective treatment options for severe obesity and related comorbidities, including hyperlipidemia, a well-established risk factor of cardiovascular diseases. Elucidating the molecular mechanisms underlying the beneficial effects of RYGB may facilitate development of equally effective, but less invasive, treatments. Recent studies have revealed that RYGB increases low-density lipoprotein receptor (LDLR) expression in the intestine of rodents. Therefore, in this study we first examined the effects of RYGB on intestinal cholesterol metabolism in human patients, and we show that they also exhibit profound changes and increased LDLR expression. We then hypothesized that the upregulation of intestinal LDLR may be sufficient to decrease circulating cholesterol levels. To this end, we generated and studied mice that overexpress human LDLR specifically in the intestine. This perturbation significantly affected intestinal metabolism, augmented fecal cholesterol excretion, and induced a reciprocal suppression of the machinery related to luminal cholesterol absorption and bile acid synthesis. Circulating cholesterol levels were significantly decreased and, remarkably, several other metabolic effects were similar to those observed in RYGB-treated rodents and patients, including improved glucose metabolism. These data highlight the importance of intestinal cholesterol metabolism for the beneficial metabolic effects of RYGB and for the treatment of hyperlipidemia.

Decreased plasma levels of perfluoroalkylated substances one year after bariatric surgery

Per- and polyfluoroalkylated substances (PFASs) are classified as persistent organic pollutants (POPs), and known to be protein bound. The aim of the present study was to determine the levels of 17 different PFASs before and one year after bariatric surgery, and to assess whether weight loss and changed serum protein concentrations could be influencing factors. Plasma samples from 63 patients were analyzed for nine perfluoroalkyl carboxylic acids (PFCAs), three perfluoroalkane sulfonic acids (PFSAs), and five perfluoroalkyl sulfonamide based substances (PASF) before and after surgery. Protein determination was performed in the corresponding serum samples. Mean weight loss one year after surgery was 32.1 kg. The plasma levels of all PFASs decreased with 4-34% compared to preoperative values, and included perfluorononanoic acid (PFNA), perfluorodecanoic acid (PFDA), perfluoroundecanoic acid (PFUnDA), and perfluorobutane sulfonate (PFBS), which have been identified with increasing levels in the general population during recent years. Serum protein concentrations also decreased with 7-8%. Although protein levels were positively correlated with PFOA, PFBS, PFHxS and PFOS, regression analysis revealed that neither weight loss nor reductions in concentrations of serum protein could explain the decreased PFAS levels. The type of surgical procedure did not influence the changes of PFAS levels between the two sample points. A reduced food intake and alterations in absorptions of nutrients after bariatric surgery may have influenced the observed decreasing plasma levels of PFASs.

Liver DNA methylation of FADS2 associates with FADS2 genotype

BACKGROUND

Non-alcoholic fatty liver disease has been associated with increased mRNA expression of FADS2 in the liver and estimated activity of delta-6 desaturase in serum, encoded by the FADS2 gene. Since DNA methylation in the FADS1/2/3 gene cluster has been previously linked with genetic variants and desaturase activities, we now aimed to discover factors regulating DNA methylation of the CpG sites annotated to FADS1/2 genes.

METHODS

DNA methylation levels in the CpG sites annotated to FADS2 and FADS1 were analyzed from liver samples of 95 obese participants of the Kuopio Obesity Surgery Study (34 men and 61 women, age 49.5 ± 7.7 years, BMI 43.0 ± 5.7 kg/m²) using the Infinium HumanMethylation450 BeadChip (Illumina). Associations between DNA methylation levels and estimated delta-6 and delta-5 desaturase enzyme activities, liver histology, hepatic mRNA expression, FADS1/2 genotypes, and erythrocyte folate levels were analyzed.

RESULTS

We found a negative correlation between DNA methylation levels of cg06781209 and cg07999042 and hepatic FADS2 mRNA expression (both p < 0.05), and with estimated delta-6 desaturase activity based on both liver and serum fatty acids (all p < 0.05). Interestingly, the methylation level of cg07999042 (p = 0.001) but not of cg06781209 (p = 0.874) was associated with FADS2 variant rs174616.

CONCLUSIONS

Genetic variants of FADS2 may contribute to the pathogenesis of non-alcoholic fatty liver disease by modifying DNA methylation.

Non-Cholesterol Sterol Concentrations as Biomarkers for Cholesterol Absorption and Synthesis in Different Metabolic Disorders: A Systematic Review

Non-cholesterol sterols are validated biomarkers for intestinal cholesterol absorption and endogenous cholesterol synthesis. However, their use in metabolic disturbances has not been systematically explored. Therefore, we conducted a systematic review to provide an overview of non-cholesterol sterols as markers for cholesterol metabolism in different metabolic disorders. Potentially relevant studies were retrieved by a systematic search of three databases in July 2018 and ninety-four human studies were included. Cholesterol-standardized levels of campesterol, sitosterol and cholestanol were collected to reflect cholesterol absorption and those of lathosterol and desmosterol to reflect cholesterol synthesis. Their use as biomarkers was examined in the following metabolic disorders: overweight/obesity (n = 16), diabetes mellitus (n = 15), metabolic syndrome (n = 5), hyperlipidemia (n = 11), cardiovascular disease (n = 17), and diseases related to intestine (n = 16), liver (n = 22) or kidney (n = 2). In general, markers for cholesterol absorption and synthesis displayed reciprocal patterns, showing that cholesterol metabolism is tightly regulated by the interplay of intestinal absorption and endogenous synthesis. Distinctive patterns for cholesterol absorption or cholesterol synthesis could be identified, suggesting that metabolic disorders can be classified as 'cholesterol absorbers or cholesterol synthesizers'. Future studies should be performed to confirm or refute these findings and to examine whether this information can be used for targeted (dietary) interventions.

Análise do perfil lipídico de pacientes submetidos à gastrectomia vertical e à derivação gástrica em Y de Roux

RESUMO Objetivo: comparar as melhorias no perfil lipídico de pacientes submetidos à gastrectomia vertical (GV) e à derivação gástrica em Y de Roux (DGYR). Metódos: estudo de coorte misto, em que foram avaliados 334 pacientes submetidos à GV e 178 pacientes submetidos à DGYR no Hospital das Clínicas da Universidade Federal de Pernambuco e no Real Hospital Português de Beneficência, Recife, PE, Brasil. Foram realizadas dosagens séricas de colesterol total, LDL, HDL e triglicerídeos no pré-operatório e com três, seis, 12 e 24 meses de seguimento. Resultados: o grupo submetido à GV foi composto por 58 homens e 276 mulheres. No grupo submetido à DGYR, foram analisados 64 homens e 114 mulheres. A média de idade foi de 37,2±20,5 anos no grupo da GV e de 41,9±11,1 anos no grupo da DGYR. O IMC médio pré-operatório foi de 39,4±2,6kg/m2 e 42,7±5,8kg/m2, para o grupo da GV e da DGYR, respectivamente. No pré-operatório, 80% dos pacientes tinha, no mínimo, uma anormalidade no perfil lipídico. Dois anos após a cirurgia houve melhora do colesterol total, LDL, HDL e triglicerídeos no grupo submetido à DGYR. No grupo submetido à GV, após dois anos houve melhora dos níveis de colesterol total, HDL e triglicerídeos, apenas. Conclusão: ambas as técnicas resultaram em melhorias no perfil lipídico, porém a DGYR foi mais efetiva.

Serum, liver and bile sitosterol and sitostanol in obese patients with and without NAFLD

Background and aims: Non-alcoholic fatty liver disease (NAFLD) associates with low levels of serum plant sterols in cross-sectional studies. In addition, it has been suggested that the hepatic sterol transport mechanisms are altered in NAFLD. Therefore, we investigated the association between serum, liver and bile plant sterols and sitostanol with NAFLD.

Methods: Out of the 138 individuals (age: 46.3 ± 8.9, body mass index: 43.3 ± 6.9 kg/m², 28% men and 72% women), 44 could be histologically categorized to have normal liver, and 94 to have NAFLD. Within the NAFLD group, 28 had simple steatosis and 27 had non-alcoholic steatohepatitis. Plant sterols and sitostanol were measured from serum (n=138), liver (n=38), and bile (n=41). The mRNA expression of genes regulating liver sterol metabolism and inflammation was measured (n=102).

Results: Liver and bile sitostanol ratios to cholesterol were higher in those with NAFLD compared to those with histologically normal liver (all P<0.022). Furthermore, liver sitostanol to cholesterol ratio correlated positively with histological steatosis and lobular inflammation (r_s > 0.407, P<0.01 for both). In contrast, liver sitosterol to cholesterol ratio correlated negatively with steatosis (r_s = −0.392, P=0.015) and lobular inflammation (r_s = −0.395, P=0.014). Transcriptomics analysis revealed suggestive correlations between serum plant sterol levels and mRNA expression.

Conclusion: Our study showed that liver and bile sitostanol ratios to cholesterol associated positively and liver sitosterol ratio to cholesterol associated negatively with liver steatosis and inflammation in obese individuals with NAFLD..

Effects of Sleeve Gastrectomy and Gastric Bypass on Postprandial Lipid Profile in Obese Type 2 Diabetic Patients: a 2-Year Follow-up

BACKGROUND

Bariatric surgery (BS) is known to favorably impact fasting lipid profile. Fasting and postprandial lipids were evaluated before and 2 years after BS in obese type 2 diabetic (T2DM) patients.

METHODS

A prospective study was conducted in 19 obese T2DM patients: ten undergoing sleeve gastrectomy (SG) and nine undergoing Roux-en-Y gastric bypass (RYGB). Before and 2 years after BS, clinical parameters and the response of lipid and incretin hormones to a mixed meal (MM) were assessed.

RESULTS

The two groups had similar characteristics at baseline. After BS, weight loss was similar in the two groups (p ≤ 0.01). Fasting glucose, insulin, and triglycerides decreased while HDL cholesterol increased in a similar way (p < 0.05); in contrast, fasting LDL cholesterol decreased only after RYGB (p < 0.05). Post-meal glucose concentrations decreased while early insulin response significantly improved after both procedures (p < 0.001 for both). Postprandial triglycerides decreased after both procedures (p < 0.05) while postprandial LDL cholesterol decreased only after RYGB (p < 0.05). Meal-GLP-1 increased postoperatively in both groups although to a greater extent after RYGB (p < 0.001 vs. SG). GIP decreased after both procedures, especially after RYGB (p = 0.003). At multivariate analysis, GLP-1 peak was the best predictor of LDL reduction (β = -0.552, p = 0.039) while the improvement of HOMA-IR (β = 0.574, p = 0.014) and weight loss (β = 0.418, p = 0.036) predicted triglycerides reduction.

CONCLUSIONS

Both surgical procedures markedly reduce fasting and postprandial triglycerides and increase HDL cholesterol levels. LDL cholesterol decreases only after RYGB through a mechanism likely mediated by the restoration of GLP-1.

Regulation of Energy Homeostasis After Gastric Bypass Surgery

The obesity epidemic continues to escalate each year in the United States more than anywhere else in the world. The existing pharmaceutical and other nonsurgical treatments for morbid obesity produce suboptimal physiologic outcomes compared with those of Roux-en-Y gastric bypass (RYGB) surgery. RYGB has been the gold standard of bariatric surgery because the beneficial long-term outcomes, which include sustainable weight loss and type 2 diabetes mellitus (T2DM) resolution, are far superior to those obtained with other bariatric surgeries. However, the current understanding of RYGB's mechanisms of actions remains limited and incomplete. There is an urgent need to understand these mechanisms as gaining this knowledge may lead to the development of innovative and less invasive procedures and/or medical devices, which can mirror the favorable outcomes of RYGB surgery. In this review, we highlight current observations of the metabolic and physiologic events following RYGB, with a particular focus on the role of the anatomical reconfiguration of the gastrointestinal tract after RYGB.

Roux-en-Y gastric bypass reduces plasma cholesterol in diet-induced obese mice by affecting trans-intestinal cholesterol excretion and intestinal cholesterol absorption

OBJECTIVE

Bariatric surgery appears as the most efficient therapeutic alternative in morbidly obese patients. In addition to its efficiency to decrease body weight, it also improves metabolic complications associated to morbid obesity, including dyslipidemia. Although the cholesterol-lowering effect varies with the bariatric procedures, the underlying molecular mechanisms remain poorly defined. This study aims to assess the consequence of both restrictive (sleeve gastrectomy; SG) and malabsorptive (Roux-en-Y gastric bypass; RYGB) procedures on cholesterol metabolism in mice.

SUBJECTS

Ten-week-old C57BL6/J males were fed with a high-fat diet for 8-14 weeks before sleeve or RYGB surgery.

RESULTS

SG has a modest and transient effect on plasma cholesterol levels, linked to a reduction in food intake. In contrast, modified RYGB led to a sustained ≈35% reduction in plasma cholesterol concentrations with a drastic increase in fecal cholesterol output. Mechanistically, RYGB exerts a synergystic effect on cholesterol metabolism by inducing the trans-intestinal cholesterol efflux and reducing the intestinal cholesterol absorption.

CONCLUSIONS

In mice, RYGB, but not sleeve, strongly favors plasma cholesterol elimination by concomitantly increasing trans-intestinal cholesterol excretion and by decreasing intestinal cholesterol absorption. Our models open new perspective for deciphering the hypocholesterolemic effects of bariatric procedures.

Impact of Roux-en-Y gastric bypass on lipid and inflammatory profiles

OBJECTIVE

To evaluate the behavior of acute phase proteins and lipid profile in patients undergoing Roux-en-Y gastric bypass.

METHODS

We conducted a prospective study, consisting of three moments: M1 - preoperative (24 hours before surgery); M2 - 30 days after surgery; and M3 - 180 days after surgery. We carried measured height and BMI, as well as determined the concentrations of acute phase proteins (C-reactive protein (CRP), albumin and Alpha-1-acid glycoprotein) and total cholesterol, LDL-c, HDL-c and triacylglycerol.

RESULTS

participants comprised 25 individuals, with a mean age of 39.28 ± 8.07, 72% female. At all times of the study there was statistically significant difference as for weight loss and BMI. We found a significant decrease in CRP concentrations between the moments M1 and M3 (p = 0.041) and between M2 and M3 (p = 0.018). There was decrease in Alpha-1-GA concentrations between M1 and M2 (p = 0.023) and between M1 and M3 (p = 0.028). The albumin values increased, but did not differ between times. Total cholesterol and triacylglycerol decreased significantly ay all times. LDL-c concentrations decreased and differed between M1 and M2 (p = 0.001) and between M1 and M3 (p = 0.001). HDL-c values increased, however only differing between M1 and M2 (p = 0.050).

CONCLUSION

Roux-en-Y gastric bypass promoted a decrease in plasma concentrations of CRP and Alpha-1-acid glycoprotein, improving lipid and inflammatory profiles.

Alterations in fatty acid metabolism in response to obesity surgery combined with dietary counseling

Background:

The effects of obesity surgery on serum and adipose tissue fatty acid (FA) profile and FA metabolism may modify the risk of obesity-related diseases.

Methods:

We measured serum (n=122) and adipose tissue (n=24) FA composition and adipose tissue mRNA expression of genes regulating FA metabolism (n=100) in participants of the Kuopio Obesity Surgery Study (KOBS, age 47.2±8.7 years, BMI 44.6±6.0, 40 men, 82 women) before and one year after obesity surgery. As part of the surgery protocol, all the subjects were instructed to add sources of unsaturated fatty acids, such as rapeseed oil and fatty fish, into their diet. The results were compared with changes in serum FA composition in 122 subjects from the Finnish Diabetes Prevention study (DPS) (age 54.3±7.1 years, BMI 32.2±4.6, 28 men, 94 women).

Results:

The proportion of saturated FAs decreased and the proportion of n-3 and n-6 FAs increased in serum triglycerides after obesity surgery (all P<0.002). Weight loss predicted changes in quantitative amounts of saturated FAs, monounsaturated FAs, n-3 and n-6 FAs in triglycerides (P<0.002 for all). Moreover, the changes in adipose tissue FAs reflected the changes in serum FAs, and some of the changes were associated with mRNA expression of elongases and desaturases in adipose tissue (all P<0.05). In line with this the estimated activity of elongase (18:1 n-7/16:1 n-7) increased significantly after obesity surgery in all lipid fractions (all P<4 × 10⁻⁷) and the increase in the estimated activity of D5D in triglycerides was associated with higher weight loss (r=0.415, P<2 × 10⁻⁶). Changes in serum FA profile were similar after obesity surgery and lifestyle intervention, except for the change in the absolute amounts of n-3 FAs between the two studies (P=0.044).

Conclusions:

Beneficial changes in serum and adipose tissue FAs after obesity surgery could be associated with changes in endogenous metabolism and diet.

Different effects of bariatric surgical procedures on dyslipidemia: a registry-based analysis

BACKGROUND

The scale and variables linked to bariatric surgery's effect on dyslipidemia have not been conclusive.

OBJECTIVE

To compare the effect of Roux-en-Y gastric bypass (RYGB), sleeve gastrectomy (SG), and adjustable gastric banding (LAGB) on dyslipidemia SETTING: National bariatric surgery registry.

METHODS

Plasma lipids and associated variables were compared at baseline and 1 year (12±4 mo) after surgery for registry patients with dyslipidemia enrolled from June 2013 to August 2014.

RESULTS

The greatest mean total-cholesterol (TC) reduction was observed post-RYGB, 226.7±26.4 to 181.3±30.9 mg/dL (19.9%, n = 208), followed by post-SG, 227.9±24.4 to 206.7±34.2 mg/dL (8.9%, n = 1515; P<.001). Normal TC levels of below 200 mg/dL were achieved by 76% post-RYGB patients compared with 43.5% post-SG patients (odds ratio [OR] = 6.24, 95% confidence interval [CI]: 3.69-10.53) and 25.6% post-LABG patients (OR = 9.66, 95% CI: 4.11-22.67; P<.01). Although equivalent patterns were observed for low-density-lipoprotein cholesterol (LDL), the levels of high-density-lipoprotein cholesterol (HDL) were most improved post-SG, reaching normal levels in 58.1% of SG male patients versus 39.5% of RYGB male patients (OR = 1.56, 95% CI: 1.04-2.35), (P = .02). The lowering of triglyceride levels by approximately 75% was comparable after SG and RYGB procedures. The type of surgery was the strongest independent predictor for all lipid level improvements or remissions. Male sex was an independent predictor for LDL normalization only (OR = 1.88, 95% CI: 1.24-2.85). Excess weight loss offered no meaningful prediction for lipid improvement (OR = 1.01-1.03).

CONCLUSION

Particular types of bariatric surgeries had different effects on dyslipidemia, independent of weight loss. Overall, the RYGB achieved the biggest reduction in plasma lipids (TC and LDL), although SG did affect HDL. Our results could aid in the decision-making process regarding the most appropriate procedure for patients with dyslipidemia.

The impact of Roux-en-Y gastric bypass surgery on normal metabolism in a porcine model

BACKGROUND

A growing body of literature on Roux-en-Y gastric bypass surgery (RYGB) has generated inconclusive results on the mechanism underlying the beneficial effects on weight loss and glycaemia, partially due to the problems of designing clinical studies with the appropriate controls. Moreover, RYGB is only performed in obese individuals, in whom metabolism is perturbed and not completely understood.

METHODS

In an attempt to isolate the effects of RYGB and its effects on normal metabolism, we investigated the effect of RYGB in lean pigs, using sham-operated pair-fed pigs as controls. Two weeks post-surgery, pigs were subjected to an intravenous glucose tolerance test (IVGTT) and circulating metabolites, hormones and lipids measured. Bile acid composition was profiled after extraction from blood, faeces and the gallbladder.

RESULTS

A similar weight development in both groups of pigs validated our experimental model. Despite similar changes in fasting insulin, RYGB-pigs had lower fasting glucose levels. During an IVGTT RYGB-pigs had higher insulin and lower glucose levels. VLDL and IDL were lower in RYGB- than in sham-pigs. RYGB-pigs had increased levels of most amino acids, including branched-chain amino acids, but these were more efficiently suppressed by glucose. Levels of bile acids in the gallbladder were higher, whereas plasma and faecal bile acid levels were lower in RYGB- than in sham-pigs.

CONCLUSION

In a lean model RYGB caused lower plasma lipid and bile acid levels, which were compensated for by increased plasma amino acids, suggesting a switch from lipid to protein metabolism during fasting in the immediate postoperative period.

Laparoscopic sleeve gastrectomy modifies cholesterol synthesis but not cholesterol absorption

BACKGROUND AND AIMS

Each bariatric surgery procedure impacts differently on cholesterol synthesis and absorption. Although a restrictive procedure, sleeve gastrectomy resolves diabetes mellitus and, like mixed-type procedures, induces early changes in gastrointestinal hormones. To our knowledge the present study is the first to assess the effects of sleeve gastrectomy on cholesterol synthesis and absorption.

METHODS AND RESULTS

42 consecutive subjects with obesity and sleeve gastrectomy candidates were included in the study together with a control group of 20 subjects without obesity. Before sleeve gastrectomy and 10 months afterwards, all subjects underwent a clinical examination, blood tests, ultrasound visceral fat area estimation and determination of plasma lathosterol, campesterol and sitosterol concentrations. After sleeve gastrectomy, significant decreases were observed in BMI, waist circumference, visceral and subcutaneous fat, blood pressure, triglycerides, insulin and glucose levels, lathosterol and HOMA-IR. HDL-C and apolipoprotein AI levels increased significantly. No significant differences emerged in LDL-C, apolipoprotein B levels or cholesterol absorption markers. Lathosterol levels correlated significantly with BMI, visceral fat area and HOMA-IR. Differences in cholesterol intake after surgery were not significantly associated with differences in lathosterol, campesterol and sitosterol concentrations.

CONCLUSIONS

Sleeve gastrectomy reduced the markers of cholesterol synthesis but did not modify cholesterol absorption. Changes in cholesterol synthesis and absorption were independent of variations in cholesterol intake, suggesting a specific sleeve gastrectomy-related effect.

Practical Recommendations of the Obesity Management Task Force of the European Association for the Study of Obesity for the Post-Bariatric Surgery Medical Management

Bariatric surgery is today the most effective long-term therapy for the management of patients with severe obesity, and its use is recommended by the relevant guidelines of the management of obesity in adults. Bariatric surgery is in general safe and effective, but it can cause new clinical problems and is associated with specific diagnostic, preventive and therapeutic needs. For clinicians, the acquisition of special knowledge and skills is required in order to deliver appropriate and effective care to the post-bariatric patient. In the present recommendations, the basic notions needed to provide first-level adequate medical care to post-bariatric patients are summarised. Basic information about nutrition, management of co-morbidities, pregnancy, psychological issues as well as weight regain prevention and management is derived from current evidences and existing guidelines. A short list of clinical practical recommendations is included for each item. It remains clear that referral to a bariatric multidisciplinary centre, preferably the one performing the original procedure, should be considered in case of more complex clinical situations.

The Effect of Bariatric Surgery Type on Lipid Profile: An Age, Sex, Body Mass Index and Excess Weight Loss Matched Study

BACKGROUND

Bariatric surgery improves lipid profile. A still unanswered question is whether this improvement is merely weight-dependent or also results from factors inherent to specificities of the bariatric procedure. We aimed to study lipid profile 1 year after bariatric surgery and compare its changes between the different procedures in patients matched for initial weight and weight loss.

METHODS

We retrospectively analysed patients submitted to Roux-en-Y gastric bypass (RYGB), adjustable gastric banding (AGB) or sleeve gastrectomy (SG) between 2010 and 2013. Patients were matched for age (±5 years), sex, pre-surgery body mass index (BMI) (±2 Kg/m(2)) and excess weight loss (EWL) (±5%). Baseline and 1-year lipid profile, its variation and percentage of variation was compared between surgeries.

RESULTS

We analysed 229 patients: 72 pairs RYGB-AGB, 47 pairs RYGB-SG and 33 pairs AGB-SG. The median age was 41 (35-52) years and 11.8% were male. Pre-operative BMI was 44.0 ± 4.6 and 32.1 ± 4.4 Kg/m(2) at 1 year. EWL at 1 year was 64.2 ± 18.9%. There were no differences in baseline lipid profile between patients submitted to different types of bariatric surgery. At 1 year, high-density lipoprotein cholesterol (HDL) and triglycerides (TG) improved similarly with all surgeries. Total cholesterol (TC) and low-density lipoprotein cholesterol (LDL) at 1 year decreased significantly more in patients submitted to RYGB than in weight-matched patients undergoing AGB or SG.

CONCLUSIONS

RYGB is the only bariatric surgery that reduces TC and LDL in age-, sex-, BMI- and EWL-matched patients. All three procedures improved TG and HDL similarly when the confounding effect of weight loss is eliminated.

A Systematic Review and Meta-analysis of the Effect of Gastric Bypass Surgery on Plasma Lipid Levels

BACKGROUND

Obesity-related dyslipidaemia comprises hypercholesterolaemia, hypertriglyceridaemia, low HDL-cholesterol and normal to raised LDL-cholesterol levels. 40% of morbidly obese surgical patients have dyslipidaemia. Roux-en-Y gastric bypass (RYGB) surgery has many beneficial metabolic effects, but the full impact on plasma lipids has not been clearly defined.

METHODS

A systematic review of electronic databases (Ovid; Medline; PubMed; Embase) between 1960 and March 2012 was performed using search terms including the following: obesity surgery, bariatric surgery, gastric bypass, cholesterol, lipids, triglycerides and non-esterified fatty acids. A total of 2442 manuscripts were screened. Papers with paired plasma lipid levels around RYGB surgery were included. Exclusions included the following: editorials, dual publications, n < 10, resulting in 75 papers of relevance. A meta-analysis was performed of the effect of RYGB surgery upon plasma lipids at different time points up to 4 years following surgery, using a random effects model.

RESULTS

Paired data were available for 7815 subjects around RYGB surgery for morbid obesity with a baseline BMI 48 kg/m(2) (n = 2331). There was a reduction in plasma total cholesterol and LDL-C from 1 month up to 4 years post-RYGB (p < 0.00001, p < 0.00001). Following RYGB, HDL-C increased from 1 year onwards (p < 0.00001), and triglyceride levels were reduced postoperatively from 3 months up to 4 years (p < 0.00001). NEFA levels were increased at 1 month postoperatively (p = 0.003), but from 3 months onwards did not differ from preoperative levels (p = 0.07).

CONCLUSIONS

RYGB surgery reverses the dyslipidaemia of obesity. These findings support the use of RYGB in the management of high cardiovascular risk lipid profiles in morbid obesity.

Plasma cathepsin D correlates with histological classifications of fatty liver disease in adults and responds to intervention

Non-alcoholic steatohepatitis (NASH) is characterized by liver lipid accumulation and inflammation. The mechanisms that trigger hepatic inflammation are poorly understood and subsequently, no specific non-invasive markers exist. We previously demonstrated a reduction in the plasma lysosomal enzyme, cathepsin D (CatD), in children with NASH compared to children without NASH. Recent studies have raised the concept that non-alcoholic fatty liver disease (NAFLD) in adults is distinct from children due to a different histological pattern in the liver. Yet, the link between plasma CatD to adult NASH was not examined. In the current manuscript, we investigated whether plasma CatD in adults correlates with NASH development and regression. Biopsies were histologically evaluated for inflammation and NAFLD in three complementary cohorts of adults (total n = 248). CatD and alanine aminotransferase (ALT) were measured in plasma. Opposite to our previous observations with childhood NASH, we observed increased levels of plasma CatD in patients with NASH compared to adults without hepatic inflammation. Furthermore, after surgical intervention, we found a reduction of plasma CatD compared to baseline. Our observations highlight a distinct pathophysiology between NASH in children and adults. The observation that plasma CatD correlated with NASH development and regression is promising for NASH diagnosis.

Changes in Lipid Profile of Obese Patients Following Contemporary Bariatric Surgery: A Meta-Analysis

BACKGROUND

Although metabolic surgery was originally performed to treat hypercholesterolemia, the effects of contemporary bariatric surgery on serum lipids have not been systematically characterized.

METHODS

MEDLINE, EMBASE, and Cochrane databases were searched for studies with ≥ 20 obese adults undergoing bariatric surgery (Roux-en-Y gastric bypass [RYGBP], adjustable gastric banding, biliopancreatic diversion [BPD], or sleeve gastrectomy). The primary outcome was change in lipids from baseline to 1 year after surgery. The search yielded 178 studies with 25,189 subjects (preoperative body mass index 45.5 ± 4.8 kg/m(2)) and 47,779 patient-years of follow-up.

RESULTS

In patients undergoing any bariatric surgery, compared with baseline, there were significant reductions in total cholesterol (TC; -28.5mg/dL), low-density lipoprotein cholesterol (LDL-C; -22.0 mg/dL), triglycerides (-61.6 mg/dL), and a significant increase in high-density lipoprotein cholesterol (6.9 mg/dL) at 1 year (P < .00001 for all). The magnitude of this change was significantly greater than that seen in nonsurgical control patients (eg LDL-C; -22.0 mg/dL vs -4.3 mg/dL). When assessed separately, the magnitude of changes varied greatly by surgical type (Pinteraction < .00001; eg, LDL-C: BPD -42.5 mg/dL, RYGBP -24.7 mg/dL, adjustable gastric banding -8.8 mg/dL, sleeve gastrectomy -7.9 mg/dL). In the cases of adjustable gastric banding (TC and LDL-C) and sleeve gastrectomy (LDL-C), the response at 1 year following surgery was not significantly different from nonsurgical control patients.

CONCLUSIONS

Contemporary bariatric surgical techniques produce significant improvements in serum lipids, but changes vary widely, likely due to anatomic alterations unique to each procedure. These differences may be relevant in deciding the most appropriate technique for a given patient.

Weight loss and improvement of lipid profiles in morbidly obese patients after laparoscopic one-anastomosis gastric bypass: 2-year follow-up

BACKGROUND

Obesity is the most frequent chronic metabolic disease globally. There is a direct correlation between increasing body mass index (BMI) and elevated total cholesterol (TC), low-density lipoprotein cholesterol (LDL), and triglycerides (Tg), and an inverse correlation with high-density lipoprotein cholesterol (HDL); all these lipid derangements are associated with an increased risk of cardiovascular disease. Our aim was to evaluate lipid profiles in morbidly obese patients before and after one-anastomosis gastric bypass (OAGB) performed at a single-center during a 2-year follow-up.

PATIENTS AND METHODS

A prospective, observational and descriptive study was carried out, including morbidly obese patients with at least one lipid abnormality, who underwent laparoscopic OAGB. Lipid profiles were evaluated preoperatively and at different intervals during a 2-year follow-up.

RESULTS

A total of 150 patients were included (73 % females and 27 % males). Mean age was 45.83 ± 10.65 years, mean BMI was 42.82 kg/m² ± 6.43, and mean weight was 116.23 kg ± 22.70; 2 years after surgery, the latter two decreased to 24.73 ± 4.43 (p < 0.001) and 67.34 ± 13.35 (p < 0.001), respectively, thus leading to a mean weight loss (WL) of 48.85 kg ± 15.64 and mean %excess WL of 71.87 ± 13.41. Tg, TC and LDL levels significantly decreased: 123.60 ± 56.34 versus 84.79 ± 33.67, 194.33 ± 43.90 versus 173.65 ± 34.84, and 124.47 ± 36.07 versus 97.36 ± 25.05, respectively (p < 0.001); HDL levels significantly increased: 43.61 ± 9.85 versus 61.56 ± 12.63 (p < 0.001).

CONCLUSION

OAGB leads to substantial and durable WL in morbidly obese patients after a 2-year follow-up. Postoperative lipid profiles significantly improved; these changes translate into theoretical relevant cardiovascular risk benefits.