Marked difference in liver fat measured by histology vs. magnetic resonance-proton density fat fraction: A meta-analysis

Background & Aims

Pathologists quantify liver steatosis as the fraction of lipid droplet-containing hepatocytes out of all hepatocytes, whereas the magnetic resonance-determined proton density fat fraction (PDFF) reflects the tissue triacylglycerol concentration. We investigated the linearity, agreement, and correspondence thresholds between histological steatosis and PDFF across the full clinical spectrum of liver fat content associated with non-alcoholic fatty liver disease.

Methods

Using individual patient-level measurements, we conducted a systematic review and meta-analysis of studies comparing histological steatosis with PDFF determined by magnetic resonance spectroscopy or imaging in adults with suspected non-alcoholic fatty liver disease. Linearity was assessed by meta-analysis of correlation coefficients and by linear mixed modelling of pooled data, agreement by Bland-Altman analysis, and thresholds by receiver operating characteristic analysis. To explain observed differences between the methods, we used RNA-seq to determine the fraction of hepatocytes in human liver biopsies.

Results

Eligible studies numbered 9 (N = 597). The relationship between PDFF and histology was predominantly linear (r = 0.85 [95% CI, 0.80-0.89]), and their values approximately coincided at 5% steatosis. Above 5% and towards higher levels of steatosis, absolute values of the methods diverged markedly, with histology exceeding PDFF by up to 3.4-fold. On average, 100% histological steatosis corresponded to a PDFF of 33.0% (29.5-36.7%). Targeting at a specificity of 90%, optimal PDFF thresholds to predict histological steatosis grades were ≥5.75% for ≥S1, ≥15.50% for ≥S2, and ≥21.35% for S3. Hepatocytes comprised 58 ± 5% of liver cells, which may partly explain the lower values of PDFF vs. histology.

Conclusions

Histological steatosis and PDFF have non-perfect linearity and fundamentally different scales of measurement. Liver fat values obtained using these methods may be rendered comparable by conversion equations or threshold values.

Impact and implications

Magnetic resonance-proton density fat fraction (PDFF) is increasingly being used to measure liver fat in place of the invasive liver biopsy. Understanding the relationship between PDFF and histological steatosis fraction is important for preventing misjudgement of clinical status or treatment effects in patient care. Our analysis revealed that histological steatosis fraction is often significantly higher than PDFF, and their association varies across the spectrum of fatty liver severity. These findings are particularly important for physicians and clinical researchers, who may use these data to interpret PDFF measurements in the context of histologically evaluated liver fat content.

Human visceral adipose tissue microvascular endothelial cell isolation and establishment of co-culture with white adipocytes to analyze cell-cell communication

Communication between adipocytes and endothelial cells (EC) is suggested to play an important role in the metabolic function of white adipose tissue. In order to generate tools to investigate in detail the physiology and communication of EC and adipocytes, a method for isolation of adipose microvascular EC from visceral adipose tissue (VAT) biopsies of subjects with obesity was developed. Moreover, mature white adipocytes were isolated from the VAT biopsies by a method adapted from a previously published Membrane aggregate adipocytes culture (MAAC) protocol. The identity and functionality of the cultivated and isolated adipose microvascular EC (AMvEC) was validated by imaging their morphology, analyses of mRNA expression, fluorescence activated cell sorting (FACS), immunostaining, low-density lipoprotein (LDL) uptake, and in vitro angiogenesis assays. Finally, we established a new trans filter co-culture system (membrane aggregate adipocyte and endothelial co-culture, MAAECC) for the analysis of communication between the two cell types. EC-adipocyte communication in this system was validated by omics analyses, revealing several altered proteins belonging to pathways such as metabolism, intracellular transport and signal transduction in adipocytes co-cultured with AMvEC. In reverse experiments, induction of several pathways including endothelial development and functions was found in AMvEC co-cultured with adipocytes. In conclusion, we developed a robust method to isolate EC from small quantities of human VAT. Furthermore, the MAAECC system established during the study enables one to study the communication between primary white adipocytes and EC or vice-versa and could also be employed for drug screening.

Roux-en-Y versus one-anastomosis gastric bypass (RYSA study): weight loss, metabolic improvements, and nutrition at 1 year after surgery, a multicenter randomized controlled trial

OBJECTIVE

Although it has been suggested that one-anastomosis gastric bypass (OAGB) is metabolically superior to the "gold standard," i.e., Roux-en-Y gastric bypass (RYGB), there is little robust evidence to prove it. Because this result may arise from the typically longer length of bypassed intestine in OAGB, here, the authors standardized the bypass length in RYGB and OAGB and compared weight loss and metabolic outcomes in a randomized controlled trial.

METHODS

The authors randomized 121 bariatric patients to RYGB (n = 61) or OAGB (n = 60) in two Finnish University Hospitals and measured weight; body composition; metabolic features (insulin sensitivity, lipids, inflammation, nutrition); and comorbidities before and 6 and 12 months after the operation.

RESULTS

Total weight loss was similar in RYGB and OAGB at 6 months (mean: 21.2% [95% CI: 19.4-23.0] vs. 22.8% [95% CI: 21.5-24.1], p = 0.136) and 12 months (25.4% [95% CI: 23.4-27.5] vs. 26.1% [95% CI: 24.2-28.9], p = 0.635). Insulin sensitivity, lipids, and inflammation improved similarly between the groups (p > 0.05). Remission of type 2 diabetes and hypercholesterolemia was marked and similar (p > 0.05) but the use of antihypertensive medications was lower (p = 0.037) and hypertension tended to improve more (p = 0.053) with RYGB versus OAGB at 12 months. Higher rates of vitamin D-25 deficiency (p < 0.05) and lower D-25 levels were observed with OAGB versus RYGB throughout the follow-up (p < 0.001). No differences in adverse effects were observed.

CONCLUSIONS

RYGB and OAGB were comparable in weight loss, metabolic improvement, remission of diabetes and hypercholesterolemia, and nutrition at 1-year follow-up. Vitamin D-25 deficiency was more prevalent with OAGB, whereas reduction in antihypertensive medications and hypertension was greater with RYGB. There is no need to change the current practices of RYGB in favor of OAGB.

Inhibition of HSD17B13 protects against liver fibrosis by inhibition of pyrimidine catabolism in nonalcoholic steatohepatitis

Nonalcoholic fatty liver disease (NAFLD) is the most common chronic liver disease, in which prognosis is determined by liver fibrosis. A common variant in hydroxysteroid 17-beta dehydrogenase 13 (HSD17B13, rs72613567-A) is associated with a reduced risk of fibrosis in NAFLD, but the underlying mechanism(s) remains unclear. We investigated the effects of this variant in the human liver and in Hsd17b13 knockdown in mice by using a state-of-the-art metabolomics approach. We demonstrate that protection against liver fibrosis conferred by the HSD17B13 rs72613567-A variant in humans and by the Hsd17b13 knockdown in mice is associated with decreased pyrimidine catabolism at the level of dihydropyrimidine dehydrogenase. Furthermore, we show that hepatic pyrimidines are depleted in two distinct mouse models of NAFLD and that inhibition of pyrimidine catabolism by gimeracil phenocopies the HSD17B13-induced protection against liver fibrosis. Our data suggest pyrimidine catabolism as a therapeutic target against the development of liver fibrosis in NAFLD.

Effectiveness of Fecal Microbiota Transplantation for Weight Loss in Patients With Obesity Undergoing Bariatric Surgery: A Randomized Clinical Trial

IMPORTANCE

Severe obesity is a major health concern. However, a few patients remain resistant to bariatric surgery and other treatments. Animal studies suggest that weight may be altered by fecal microbiota transplantation (FMT) from a lean donor.

OBJECTIVE

To determine whether FMT from a lean donor reduces body weight and further improves the results of bariatric surgery.

DESIGN, SETTING, AND PARTICIPANTS

This double-blinded, placebo-controlled, multicenter, randomized clinical trial was conducted in 2018 to 2021 among adult individuals with severe obesity treated at 2 bariatric surgery centers in Finland and included 18 months of follow-up. Patients eligible for bariatric surgery were recruited for the study. Data were analyzed from March 2021 to May 2022.

INTERVENTIONS

FMT from a lean donor or from the patient (autologous placebo) was administered by gastroscopy into the duodenum. Bariatric surgery was performed 6 months after the baseline intervention using laparoscopic Roux-en-Y gastric bypass (LRYGB) or laparoscopic sleeve gastrectomy (LSG).

MAIN OUTCOMES AND MEASURES

The main outcome was weight reduction measured as the percentage of total weight loss (TWL).

RESULTS

Forty-one patients were recruited to participate in the study and were included in the final analysis (29 women [71.1%]; mean [SD] age, 48.7 [8.7] years; mean [SD] body mass index, 42.5 [6.0]). A total of 21 patients received FMT from a lean donor, and 20 received an autologous placebo. Six months after FMT, 34 patients underwent LRYGB and 4 underwent LSG. Thirty-four patients (82.9%) attended the last visit 18 months after the baseline visit. The percentage of TWL at 6 months was 4.8% (95% CI, 2.7% to 7.0%; P < .001) in the FMT group and 4.6% (95% CI, 1.5% to 7.6%; P = .006) in the placebo group, but no difference was observed between the groups. At 18 months from the baseline (ie, 12 months after surgery), the percentage of TWL was 25.3% (95% CI, 19.5 to 31.1; P < .001) in the FMT group and 25.2% (95% CI, 20.2 to 30.3; P < .001) in the placebo group; however, no difference was observed between the groups.

CONCLUSIONS AND RELEVANCE

FMT did not affect presurgical and postsurgical weight loss. Further studies are needed to elucidate the possible role of FMT in obesity.

TRIAL REGISTRATION

ClinicalTrials.gov Identifier: NCT03391817.

The human liver lipidome is significantly related to the lipid composition and aggregation susceptibility of low-density lipoprotein (LDL) particles

BACKGROUND AND AIMS

The susceptibility of low-density lipoprotein (LDL) to aggregation predicts atherosclerotic cardiovascular disease. However, causes of interindividual variation in LDL lipid composition and aggregation susceptibility remain unclear. We examined whether the lipid composition and aggregation susceptibility of LDL reflect the lipid composition of the human liver.

METHODS

Liver biopsies and blood samples for isolation of LDL particles were obtained from 40 obese subjects (BMI 45.9 ± 6.1 kg/m², age 43 ± 8 years). LDL was isolated using sequential ultracentrifugation and lipidomic analyses of liver and LDL samples were determined using ultra-high performance liquid chromatography-mass spectrometry. LDL aggregation susceptibility ex vivo was analyzed by inducing aggregation by human recombinant secretory sphingomyelinase and following aggregate formation.

RESULTS

The composition (acyl carbon number and double bond count) of hepatic triglycerides, phosphatidylcholines, and sphingomyelins (SMs) was closely associated with that of LDL particles. Hepatic dihydroceramides and ceramides were positively correlated with concentrations of the corresponding SM species in LDL as well with LDL aggregation. These relationships remained statistically significant after adjustment for age, sex, and body mass index.

CONCLUSIONS

Lipid composition of LDL reflects that of the human liver in obese patients. Changes in hepatic sphingolipid metabolism may contribute to interindividual variation of LDL lipid composition and susceptibility to aggregation.

Women's Reasons to Seek Bariatric Surgery and Their Expectations on the Surgery Outcome - a Multicenter Study from Five European Countries

Purpose

Understanding patients’ reasons for having bariatric surgery and their expectation on surgery outcomes is important to provide the best clinical practice and reduce unrealistic expectations. It is unknown if reasons and expectations differ between countries. We aimed to investigate the reasons for seeking bariatric surgery and expectations of surgical outcomes among patients in five European countries.

Methods

In total, 250 women accepted for bariatric surgery were recruited: 50 women each from Finland, Germany, Norway, Sweden, and the Netherlands. Participants ranked 14 reasons for seeking surgery, and reported the three primary reasons. They also reported expectations on weight loss and impact of surgery vs. lifestyle on weight loss outcomes.

Results

Mean age and body mass index were 42.9 ± 11.5 years and 45.1 ± 6.2 kg/m², respectively. Weight loss and improved co-morbidity were ranked as the most important reasons. Participants expected to lose between 70.8 and 94.3% of their excessive weight. The expected impact of surgery as a driver of weight loss was higher in Germany and the Netherlands compared to in Finland, Norway, and Sweden where participants expected lifestyle changes to also have an impact.

Conclusion

Weight loss and improved co-morbidities were the main reasons for undergoing bariatric surgery. Expectations on weight loss were generally very high, but expectations of surgery vs. lifestyle as the main driver of weight loss differed between countries. While some patients understand the importance of lifestyle change and maintenance of a healthy lifestyle after surgery in order to obtain a successful weight loss, other may need additional counselling.

Graphical Abstract

Supplementary Information

The online version contains supplementary material available at 10.1007/s11695-022-06280-w.

Effect of Laparoscopic Sleeve Gastrectomy vs Roux-en-Y Gastric Bypass on Weight Loss, Comorbidities, and Reflux at 10 Years in Adult Patients With Obesity: The SLEEVEPASS Randomized Clinical Trial

Importance

Long-term results from randomized clinical trials comparing laparoscopic sleeve gastrectomy (LSG) with laparoscopic Roux-en-Y-gastric bypass (LRYGB) are limited.

Objective

To compare long-term outcomes of weight loss and remission of obesity-related comorbidities and the prevalence of gastroesophageal reflux symptoms (GERD), endoscopic esophagitis, and Barrett esophagus (BE) after LSG and LRYGB at 10 years.

Design, Setting, and Participants

This 10-year observational follow-up evaluated patients in the Sleeve vs Bypass (SLEEVEPASS) multicenter equivalence randomized clinical trial comparing LSG and LRYGB in the treatment of severe obesity in which 240 patients aged 18 to 60 years with median body mass index of 44.6 were randomized to LSG (n = 121) or LRYGB (n = 119). The initial trial was conducted from April 2008 to June 2010 in Finland, with last follow-up on January 27, 2021.

Interventions

LSG or LRYGB.

Main Outcomes and Measures

The primary end point was 5-year percentage excess weight loss (%EWL). This current analysis focused on 10-year outcomes with special reference to reflux and BE.

Results

At 10 years, of 240 randomized patients (121 randomized to LSG and 119 to LRYGB; 167 women [69.6%]; mean [SD] age, 48.4 [9.4] years; mean [SD] baseline BMI, 45.9 [6.0]), 2 never underwent surgery and there were 10 unrelated deaths; 193 of the remaining 228 patients (85%) completed follow-up on weight loss and comorbidities, and 176 of 228 (77%) underwent gastroscopy. Median (range) %EWL was 43.5% (2.1%-109.2%) after LSG and 50.7% (1.7%-111.7%) after LRYGB. Mean estimate %EWL was not equivalent between the procedures; %EWL was 8.4 (95% CI, 3.1-13.6) higher in LRYGB. After LSG and LRYGB, there was no statistically significant difference in type 2 diabetes remission (26% and 33%, respectively; P = .63), dyslipidemia (19% and 35%, respectively; P = .23), or obstructive sleep apnea (16% and 31%, respectively; P = .30). Hypertension remission was superior after LRYGB (8% vs 24%; P = .04). Esophagitis was more prevalent after LSG (31% vs 7%; P < .001) with no statistically significant difference in BE (4% vs 4%; P = .29). The overall reoperation rate was 15.7% for LSG and 18.5% for LRYGB (P = .57).

Conclusions and Relevance

At 10 years, %EWL was greater after LRYGB and the procedures were not equivalent for weight loss, but both LSG and LRYGB resulted in good and sustainable weight loss. Esophagitis was more prevalent after LSG, but the cumulative incidence of BE was markedly lower than in previous trials and similar after both procedures.

Trial Registration

ClinicalTrials.gov Identifier: NCT00793143.

Obesity Modifies the Performance of Fibrosis Biomarkers in Nonalcoholic Fatty Liver Disease

CONTEXT

Guidelines recommend blood-based fibrosis biomarkers to identify advanced nonalcoholic fatty liver disease (NAFLD), which is particularly prevalent in patients with obesity.

OBJECTIVE

To study whether the degree of obesity affects the performance of liver fibrosis biomarkers in NAFLD.

DESIGN

Cross-sectional cohort study comparing simple fibrosis scores [Fibrosis-4 Index (FIB-4); NAFLD Fibrosis Score (NFS); aspartate aminotransferase to platelet ratio index; BARD (body mass index, aspartate-to-alanine aminotransferase ratio, diabetes); Hepamet Fibrosis Score (HFS)] and newer scores incorporating neo-epitope biomarkers PRO-C3 (ADAPT, FIBC3) or cytokeratin 18 (MACK-3).

SETTING

Tertiary referral center.

PATIENTS

We recruited overweight/obese patients from endocrinology (n = 307) and hepatology (n = 71) clinics undergoing a liver biopsy [median body mass index (BMI) 40.3 (interquartile range 36.0-44.7) kg/m2]. Additionally, we studied 859 less obese patients with biopsy-proven NAFLD to derive BMI-adjusted cutoffs for NFS.

MAIN OUTCOME MEASURES

Biomarker area under the receiver operating characteristic (AUROC), sensitivity, specificity, and predictive values to identify histological stage ≥F3 fibrosis or nonalcoholic steatohepatitis with ≥F2 fibrosis [fibrotic nonalcoholic steatohepatitis (NASH)].

RESULTS

The scores with an AUROC ≥0.85 to identify ≥F3 fibrosis were ADAPT, FIB-4, FIBC3, and HFS. For fibrotic NASH, the best predictors were MACK-3 and ADAPT. The specificities of NFS, BARD, and FIBC3 deteriorated as a function of BMI. We derived and validated new cutoffs for NFS to rule in/out ≥F3 fibrosis in groups with BMIs <30.0, 30.0 to 39.9, and ≥40.0 kg/m2. This optimized its performance at all levels of BMI. Sequentially combining FIB-4 with ADAPT or FIBC3 increased specificity to diagnose ≥F3 fibrosis.

CONCLUSIONS

In obese patients, the best-performing fibrosis biomarkers are ADAPT and the inexpensive FIB-4, which are unaffected by BMI. The widely used NFS loses specificity in obese individuals, which may be corrected with BMI-adjusted cutoffs.

Distinct contributions of metabolic dysfunction and genetic risk factors in the pathogenesis of non-alcoholic fatty liver disease

BACKGROUND & AIMS

There is substantial inter-individual variability in the risk of non-alcoholic fatty liver disease (NAFLD). Part of which is explained by insulin resistance (IR) ('MetComp') and part by common modifiers of genetic risk ('GenComp'). We examined how IR on the one hand and genetic risk on the other contribute to the pathogenesis of NAFLD.

METHODS

We studied 846 individuals: 492 were obese patients with liver histology and 354 were individuals who underwent intrahepatic triglyceride measurement by proton magnetic resonance spectroscopy. A genetic risk score was calculated using the number of risk alleles in PNPLA3, TM6SF2, MBOAT7, HSD17B13 and MARC1. Substrate concentrations were assessed by serum NMR metabolomics. In subsets of participants, non-esterified fatty acids (NEFAs) and their flux were assessed by D5-glycerol and hyperinsulinemic-euglycemic clamp (n = 41), and hepatic de novo lipogenesis (DNL) was measured by D2O (n = 61).

RESULTS

We found that substrate surplus (increased concentrations of 28 serum metabolites including glucose, glycolytic intermediates, and amino acids; increased NEFAs and their flux; increased DNL) characterized the 'MetComp'. In contrast, the 'GenComp' was not accompanied by any substrate excess but was characterized by an increased hepatic mitochondrial redox state, as determined by serum β-hydroxybutyrate/acetoacetate ratio, and inhibition of hepatic pathways dependent on tricarboxylic acid cycle activity, such as DNL. Serum β-hydroxybutyrate/acetoacetate ratio correlated strongly with all histological features of NAFLD. IR and hepatic mitochondrial redox state conferred additive increases in histological features of NAFLD.

CONCLUSIONS

These data show that the mechanisms underlying 'Metabolic' and 'Genetic' components of NAFLD are fundamentally different. These findings may have implications with respect to the diagnosis and treatment of NAFLD.

LAY SUMMARY

The pathogenesis of non-alcoholic fatty liver disease can be explained in part by a metabolic component, including obesity, and in part by a genetic component. Herein, we demonstrate that the mechanisms underlying these components are fundamentally different: the metabolic component is characterized by hepatic oversupply of substrates, such as sugars, lipids and amino acids. In contrast, the genetic component is characterized by impaired hepatic mitochondrial function, making the liver less able to metabolize these substrates.

Exposure to environmental contaminants is associated with altered hepatic lipid metabolism in non-alcoholic fatty liver disease

BACKGROUND & AIMS

Recent experimental models and epidemiological studies suggest that specific environmental contaminants (ECs) contribute to the initiation and pathology of non-alcoholic fatty liver disease (NAFLD). However, the underlying mechanisms linking EC exposure with NAFLD remain poorly understood and there is no data on their impact on the human liver metabolome. Herein, we hypothesized that exposure to ECs, particularly perfluorinated alkyl substances (PFAS), impacts liver metabolism, specifically bile acid metabolism.

METHODS

In a well-characterized human NAFLD cohort of 105 individuals, we investigated the effects of EC exposure on liver metabolism. We characterized the liver (via biopsy) and circulating metabolomes using 4 mass spectrometry-based analytical platforms, and measured PFAS and other ECs in serum. We subsequently compared these results with an exposure study in a PPARa-humanized mouse model.

RESULTS

PFAS exposure appears associated with perturbation of key hepatic metabolic pathways previously found altered in NAFLD, particularly those related to bile acid and lipid metabolism. We identified stronger associations between the liver metabolome, chemical exposure and NAFLD-associated clinical variables (liver fat content, HOMA-IR), in females than males. Specifically, we observed PFAS-associated upregulation of bile acids, triacylglycerols and ceramides, and association between chemical exposure and dysregulated glucose metabolism in females. The murine exposure study further corroborated our findings, vis-à-vis a sex-specific association between PFAS exposure and NAFLD-associated lipid changes.

CONCLUSIONS

Females may be more sensitive to the harmful impacts of PFAS. Lipid-related changes subsequent to PFAS exposure may be secondary to the interplay between PFAS and bile acid metabolism.

LAY SUMMARY

There is increasing evidence that specific environmental contaminants, such as perfluorinated alkyl substances (PFAS), contribute to the progression of non-alcoholic fatty liver disease (NAFLD). However, it is poorly understood how these chemicals impact human liver metabolism. Here we show that human exposure to PFAS impacts metabolic processes associated with NAFLD, and that the effect is different in females and males.

Computational modelling of self-reported dietary carbohydrate intake on glucose concentrations in patients undergoing Roux-en-Y gastric bypass versus one-anastomosis gastric bypass

OBJECTIVES

Our aim was to investigate in a real-life setting the use of machine learning for modelling the postprandial glucose concentrations in morbidly obese patients undergoing Roux-en-Y gastric bypass (RYGB) or one-anastomosis gastric bypass (OAGB).

METHODS

As part of the prospective randomized open-label trial (RYSA), data from obese (BMI ≥35 kg/m2) non-diabetic adult participants were included. Glucose concentrations, measured with FreeStyle Libre, were recorded over 14 preoperative and 14 postoperative days. During these periods, 3-day food intake was self-reported. A machine learning model was applied to estimate glycaemic responses to the reported carbohydrate intakes before and after the bariatric surgeries.

RESULTS

Altogether, 10 participants underwent RYGB and 7 participants OAGB surgeries. The glucose concentrations and carbohydrate intakes were reduced postoperatively in both groups. The relative time spent in hypoglycaemia increased regardless of the operation (RYGB, from 9.2 to 28.2%; OAGB, from 1.8 to 37.7%). Postoperatively, we observed an increase in the height of the fitted response curve and a reduction in its width, suggesting that the same amount of carbohydrates caused a larger increase in the postprandial glucose response and that the clearance of the meal-derived blood glucose was faster, with no clinically meaningful differences between the surgeries.

CONCLUSIONS

A detailed analysis of the glycaemic responses using food diaries has previously been difficult because of the noisy meal data. The utilized machine learning model resolved this by modelling the uncertainty in meal times. Such an approach is likely also applicable in other applications involving dietary data. A marked reduction in overall glycaemia, increase in postprandial glucose response, and rapid glucose clearance from the circulation immediately after surgery are evident after both RYGB and OAGB. Whether nondiabetic individuals would benefit from monitoring the post-surgery hypoglycaemias and the potential to prevent them by dietary means should be investigated.KEY MESSAGESThe use of a novel machine learning model was applicable for combining patient-reported data and time-series data in this clinical study.Marked increase in postprandial glucose concentrations and rapid glucose clearance were observed after both Roux-en-Y gastric bypass and one-anastomosis gastric bypass surgeries.Whether nondiabetic individuals would benefit from monitoring the post-surgery hypoglycaemias and the potential to prevent them by dietary means should be investigated.

Defining Global Benchmarks in Elective Secondary Bariatric Surgery Comprising Conversional, Revisional, and Reversal Procedures

OBJECTIVE

To define "best possible" outcomes for secondary bariatric surgery (BS).

BACKGROUND

Management of poor response and of long-term complications after BS is complex and under-investigated. Indications and types of reoperations vary widely and postoperative complication rates are higher compared to primary BS.

METHODS

Out of 44,884 BS performed in 18 high-volume centers from 4 continents between 06/2013-05/2019, 5,349 (12%) secondary BS cases were identified. Twenty-one outcome benchmarks were established in low-risk patients, defined as the 75th percentile of the median outcome values of centers. Benchmark cases had no previous laparotomy, diabetes, sleep apnea, cardiopathy, renal insufficiency, inflammatory bowel disease, immunosuppression, thromboembolic events, BMI> 50 kg/m2 or age> 65 years.

RESULTS

The benchmark cohort included 3143 cases, mainly females (85%), aged 43.8 ± 10 years, 8.4 ± 5.3 years after primary BS, with a BMI 35.2 ± 7 kg/m2. Main indications were insufficient weight loss (43%) and gastro-esophageal reflux disease/dysphagia (25%). 90-days postoperatively, 14.6% of benchmark patients presented ≥1 complication, mortality was 0.06% (n = 2). Significantly higher morbidity was observed in non-benchmark cases (OR 1.37) and after conversional/reversal or revisional procedures with gastrointestinal suture/stapling (OR 1.84). Benchmark cutoffs for conversional BS were ≤4.5% re-intervention, ≤8.3% re-operation 90-days postoperatively. At 2-years (IQR 1-3) 15.6% of benchmark patients required a reoperation.

CONCLUSION

Secondary BS is safe, although postoperative morbidity exceeds the established benchmarks for primary BS. The excess morbidity is due to an increased risk of gastrointestinal leakage and higher need for intensive care. The considerable rate of tertiary BS warrants expertise and future research to optimize the management of non-success after BS.

Defining global benchmarks in elective secondary bariatric surgery comprising conversional, revisional and reversal procedures

Objective

Management of poor response and of long-term complications after bariatric surgery (BS) is complex and under-investigated. Indications and types of reoperations vary widely and postoperative complication rates are higher compared to primary BS. Benchmarking uses best performance in a given field as reference point for improvement. Our aim was to define ‘‘best possible’’ outcomes for elective secondary BS.

Methods

The establishment of benchmarks in secondary BS followed a standardized methodology, based on recommendations of a Delphi consensus panel of experts. This multicenter study analyzed patients undergoing elective secondary BS in 18 high-volume centers on 4 continents from 06/2013 to 05/2019. Twenty-one outcome benchmarks were established in low-risk patients, defined as the 75th percentile of the median outcome values of the centers. Benchmark cases had no: previous laparotomy, diabetes, sleep apnea, cardiopathy, renal insufficiency, inflammatory bowel disease, immunosuppression, history of thromboembolic events, BMI&gt;50kg/m2 or age&gt;65 years. Descriptive statistics, multivariate logistic regression and data visualization were performed using the R software.

Results

Out of 44’884 elective bariatric procedures performed in the participating centers, 5’328 secondary BS cases were identified. The benchmark cohort included 3143 cases, mainly females (85%), aged 43.8±10 years, 8.4±5.3 years after primary BS, with a body mass index 35.2±7kg/m2. Main indications were insufficient weight loss (43%) and gastro-esophageal reflux disease/dysphagia (25%). 90-days postoperatively, 14.57% of benchmark patients presented ≥1 complication, mortality was 0.06% (n = 2). Significantly higher morbidity was observed in non-benchmark cases (OR 1.36) and after conversional or revisional procedures with gastrointestinal suture/stapling (OR 1.7). Benchmark cutoffs at 90-days postoperatively were ≤5.8% re-intervention and ≤8.8% re-operation rate. At 2-years (IQR 1-3) 15.6% of benchmark patients required a reoperation.

Conclusion

Secondary BS is safe, although postoperative morbidity exceeds the established benchmarks for primary BS. The excess morbidity is due to an increased risk of gastrointestinal leakage and higher need for intensive care. The considerable rate of tertiary BS warrants expertise and future research to optimize the management of non-success after BS.

Laparoscopic Roux-en-Y gastric bypass versus laparoscopic sleeve gastrectomy: 5-year outcomes of merged data from two randomized clinical trials (SLEEVEPASS and SM-BOSS)

BACKGROUND

Laparoscopic sleeve gastrectomy (LSG) and Roux-en-Y gastric bypass (LRYGB) are both effective surgical procedures to achieve weight reduction in patients with obesity. The trial objective was to merge individual-patient data from two RCTs to compare outcomes after LSG and LRYGB.

METHODS

Five-year outcomes of the Finnish SLEEVEPASS and Swiss SM-BOSS RCTs comparing LSG with LRYGB were analysed. Both original trials were designed to evaluate weight loss. Additional patient-level data on type 2 diabetes (T2DM), obstructive sleep apnoea, and complications were retrieved. The primary outcome was percentage excess BMI loss (%EBMIL). Secondary predefined outcomes in both trials included total weight loss, remission of co-morbidities, improvement in quality of life (QoL), and overall morbidity.

RESULTS

At baseline, 228 LSG and 229 LRYGB procedures were performed. Five-year follow-up was available for 199 of 228 patients (87.3 per cent) after LSG and 199 of 229 (87.1 per cent) after LRYGB. Model-based mean estimate of %EBMIL was 7.0 (95 per cent c.i. 3.5 to 10.5) percentage points better after LRYGB than after LSG  (62.7 versus 55.5 per cent respectively; P < 0.001). There was no difference in remission of T2DM, obstructive sleep apnoea or QoL improvement; remission for hypertension was better after LRYGB compared with LSG (60.3 versus 44.9 per cent; P = 0.049). The complication rate was higher after LRYGB than LSG (37.2 versus 22.5 per cent; P = 0.001), but there was no difference in mean Comprehensive Complication Index value (30.6 versus 31.0 points; P = 0.859).

CONCLUSION

Although LRYGB induced greater weight loss and better amelioration of hypertension than LSG, there was no difference in remission of T2DM, obstructive sleep apnoea, or QoL at 5 years. There were more complications after LRYGB, but the individual burden for patients with complications was similar after both operations.

Bile Reflux is a Common Finding in the Gastric Pouch After One Anastomosis Gastric Bypass

INTRODUCTION

Data on postoperative bile reflux after one anastomosis gastric bypass (OAGB) is lacking. Bile reflux scintigraphy (BRS) has been shown to be a reliable non-invasive tool to assess bile reflux after OAGB. We set out to study bile reflux after OAGB with BRS and endoscopy in a prospective series (RYSA Trial).

METHODS

Forty patients (29 women) underwent OAGB between November 2016 and December 2018. Symptoms were reported and upper gastrointestinal endoscopy (UGE) was done preoperatively. Six months after OAGB, bile reflux was assessed in UGE findings and as tracer activity found in gastric tube and esophagus in BRS (follow-up rate 95%).

RESULTS

Twenty-six patients (68.4%) had no bile reflux in BRS. Twelve patients (31.6%) had bile reflux in the gastric pouch in BRS and one of them (2.6%) had bile reflux also in the esophagus 6 months postoperatively. Mean bile reflux activity in the gastric pouch was 5.2% (1-21%) of total activity. De novo findings suggestive of bile reflux (esophagitis, stomal ulcer, foveolar inflammation of gastric pouch) were found for 15 patients (39.5%) in postoperative UGE. BRS and UGE findings were significantly associated (P = 0.022). Eight patients experienced de novo reflux symptoms at 6 months, that were significantly associated with BRS and de novo UGE findings postoperatively (P = 0.033 and 0.0005, respectively).

CONCLUSION

Postoperative bile reflux in the gastric pouch after OAGB is a common finding in scintigraphy and endoscopy. The long-term effects of bile exposure will be analyzed in future reports after a longer follow-up.

TRIAL REGISTRATION

Clinical Trials Identifier NCT02882685.

Effect of Laparoscopic Sleeve Gastrectomy vs Roux-en-Y Gastric Bypass on Weight Loss and Quality of Life at 7 Years in Patients With Morbid Obesity: The SLEEVEPASS Randomized Clinical Trial

Importance

Laparoscopic sleeve gastrectomy (LSG) is currently the predominant bariatric procedure, although long-term weight loss and quality-of-life (QoL) outcomes compared with laparoscopic Roux-en-Y gastric bypass (LRYGB) are lacking.

Objective

To determine weight loss equivalence of LSG and LRYGB at 7 years in patients with morbid obesity, with special reference to long-term QoL.

Design, Setting, and Participants

The SLEEVE vs byPASS (SLEEVEPASS) multicenter, multisurgeon, open-label, randomized clinical equivalence trial was conducted between March 10, 2008, and June 2, 2010, in Finland. The trial enrolled 240 patients with morbid obesity aged 18 to 60 years who were randomized to undergo either LSG or LRYGB with a 7-year follow-up (last follow-up, September 26, 2017). Analysis was conducted on an intention-to-treat basis. Statistical analysis was performed from June 4, 2018, to November 8, 2019.

Interventions

Laparoscopic sleeve gastrectomy (n = 121) or LRYGB (n = 119).

Main Outcomes and Measures

The primary end point was percentage excess weight loss (%EWL) at 5 years. Secondary predefined follow-up time points were 7, 10, 15, and 20 years, with included 7-year secondary end points of QoL and morbidity. Disease-specific QoL (DSQoL; Moorehead-Ardelt Quality of Life questionnaire [range of scores, -3 to 3 points, where a higher score indicates better QoL]) and general health-related QoL (HRQoL; 15D questionnaire [0-1 scale for all 15 dimensions, with 1 indicating full health and 0 indicating death]) were measured preoperatively and at 1, 3, 5, and 7 years postoperatively concurrently with weight loss.

Results

Of 240 patients (167 women [69.6%]; mean [SD] age, 48.4 [9.4] years; mean [SD] baseline body mass index, 45.9 [6.0]), 182 (75.8%) completed the 7-year follow-up. The mean %EWL was 47% (95% CI, 43%-50%) after LSG and 55% (95% CI, 52%-59%) after LRYGB (difference, 8.7 percentage units [95% CI, 3.5-13.9 percentage units]). The mean (SD) DSQoL total score at 7 years was 0.50 (1.14) after LSG and 0.49 (1.06) after LRYGB (P = .63), and the median HRQoL total score was 0.88 (interquartile range [IQR], 0.78-0.95) after LSG and 0.87 (IQR, 0.78-0.95) after LRYGB (P = .37). Greater weight loss was associated with better DSQoL (r = 0.26; P < .001). At 7 years, mean (SD) DSQoL scores improved significantly compared with baseline (LSG, 0.50 [1.14] vs 0.10 [0.94]; and LRYGB, 0.49 [1.06] vs 0.12 [1.12]; P < .001), unlike median HRQoL scores (LSG, 0.88 [IQR, 0.78-0.95] vs 0.87 [IQR, 0.78-0.90]; and LRYGB, 0.87 [IQR, 0.78-0.92] vs 0.85 [IQR, 0.77-0.91]; P = .07). The overall morbidity rate was 24.0% (29 of 121) for LSG and 28.6% (34 of 119) for LRYGB (P = .42).

Conclusions and Relevance

This study found that LSG and LRYGB were not equivalent in %EWL at 7 years. Laparoscopic Roux-en-Y gastric bypass resulted in greater weight loss than LSG, but the difference was not clinically relevant based on the prespecified equivalence margins. There was no difference in long-term QoL between the procedures. Bariatric surgery was associated with significant long-term DSQoL improvement, and greater weight loss was associated with better DSQoL.

Trial Registration

ClinicalTrials.gov Identifier: NCT00793143.

Assessment of Lifestyle Factors Helps to Identify Liver Fibrosis Due to Non-Alcoholic Fatty Liver Disease in Obesity

Only some individuals with obesity develop liver fibrosis due to non-alcoholic fatty liver disease (NAFLD-fibrosis). We determined whether detailed assessment of lifestyle factors in addition to physical, biochemical and genetic factors helps in identification of these patients. A total of 100 patients with obesity (mean BMI 40.0 ± 0.6 kg/m²) referred for bariatric surgery at the Helsinki University Hospital underwent a liver biopsy to evaluate liver histology. Physical activity was determined by accelerometer recordings and by the Modifiable Activity Questionnaire, diet by the FINRISK Food Frequency Questionnaire, and other lifestyle factors, such as sleep patterns and smoking, by face-to-face interviews. Physical and biochemical parameters and genetic risk score (GRS based on variants in PNPLA3, TM6SF2, MBOAT7 and HSD17B13) were measured. Of all participants 49% had NAFLD-fibrosis. Independent predictors of NAFLD-fibrosis were low moderate-to-vigorous physical activity, high red meat intake, low carbohydrate intake, smoking, HbA_1c, triglycerides and GRS. A model including these factors (areas under the receiver operating characteristics curve (AUROC) 0.90 (95% CI 0.84–0.96)) identified NAFLD-fibrosis significantly more accurately than a model including all but lifestyle factors (AUROC 0.82 (95% CI 0.73–0.91)) or models including lifestyle, physical and biochemical, or genetic factors alone. Assessment of lifestyle parameters in addition to physical, biochemical and genetic factors helps to identify obese patients with NAFLD-fibrosis.

Errors-in-Variables Modeling of Personalized Treatment-Response Trajectories

Estimating the impact of a treatment on a given response is needed in many biomedical applications. However, methodology is lacking for the case when the response is a continuous temporal curve, treatment covariates suffer extensively from measurement error, and even the exact timing of the treatments is unknown. We introduce a novel method for this challenging scenario. We model personalized treatment-response curves as a combination of parametric response functions, hierarchically sharing information across individuals, and a sparse Gaussian process for the baseline trend. Importantly, our model accounts for errors not only in treatment covariates, but also in treatment timings, a problem arising in practice for example when data on treatments are based on user self-reporting. We validate our model with simulated and real patient data, and show that in a challenging application of estimating the impact of diet on continuous blood glucose measurements, accounting for measurement error significantly improves estimation and prediction accuracy.

The PNPLA3-I148M Variant Confers an Antiatherogenic Lipid Profile in Insulin-resistant Patients

CONTEXT

The I148M (rs738409-G) variant in PNPLA3 increases liver fat content but may be protective against cardiovascular disease. Insulin resistance (IR) amplifies the effect of PNPLA3-I148M on liver fat.

OBJECTIVE

To study whether PNPLA3-I148M confers an antihyperlipidemic effect in insulin-resistant patients.

DESIGN

Cross-sectional study comparing the impact of PNPLA3-I148M on plasma lipids and lipoproteins in 2 cohorts, both divided into groups based on rs738409-G allele carrier status and median HOMA-IR.

SETTING

Tertiary referral center.

PATIENTS

A total of 298 obese patients who underwent a liver biopsy during bariatric surgery (bariatric cohort: age 49 ± 9 years, body mass index [BMI] 43.2 ± 6.8 kg/m2), and 345 less obese volunteers in whom liver fat was measured by proton magnetic resonance spectroscopy (nonbariatric cohort: age 45 ± 14 years, BMI 29.7 ± 5.7 kg/m2).

MAIN OUTCOME MEASURES

Nuclear magnetic resonance profiling of plasma lipids, lipoprotein particle subclasses and their composition.

RESULTS

In both cohorts, individuals carrying the PNPLA3-I148M variant had significantly higher liver fat content than noncarriers. In insulin-resistant and homozygous carriers, PNPLA3-I148M exerted a distinct antihyperlipidemic effect with decreased very-low-density lipoprotein (VLDL) and low-density lipoprotein (LDL) particles and their constituents, and increased high-density lipoprotein particles and their constituents, compared with noncarriers. VLDL particles were smaller and LDL particles larger in PNPLA3-I148M carriers. These changes were geometrically opposite to those due to IR. PNPLA3-I148M did not have a measurable effect in patients with lower IR, and its effect was smaller albeit still significant in the less obese than in the obese cohort.

CONCLUSIONS

PNPLA3-I148M confers an antiatherogenic plasma lipid profile particularly in insulin-resistant individuals.

The PNPLA3-I148M variant increases polyunsaturated triglycerides in human adipose tissue

BACKGROUND & AIMS

The I148M variant in PNPLA3 is the major genetic risk factor for non-alcoholic fatty liver disease (NAFLD). The liver is enriched with polyunsaturated triglycerides (PUFA-TGs) in PNPLA3-I148M carriers. Gene expression data indicate that PNPLA3 is liver-specific in humans, but whether it functions in adipose tissue (AT) is unknown. We investigated whether PNPLA3-I148M modifies AT metabolism in human NAFLD.

METHODS

Profiling of the AT lipidome and fasting serum non-esterified fatty acid (NEFA) composition was conducted in 125 volunteers (PNPLA3^148MM/MI , n = 63; PNPLA3^148II , n = 62). AT fatty acid composition was determined in 50 volunteers homozygous for the variant (PNPLA3^148MM , n = 25) or lacking the variant (PNPLA3^148II , n = 25). Whole-body insulin sensitivity of lipolysis was determined using [² H₅ ]glycerol, and PNPLA3 mRNA and protein levels were measured in subcutaneous AT and liver biopsies in a subset of the volunteers.

RESULTS

PUFA-TGs were significantly increased in AT in carriers versus non-carriers of PNPLA3-I148M. The variant did not alter the rate of lipolysis or the composition of fasting serum NEFAs. PNPLA3 mRNA was 33-fold higher in the liver than in AT (P < .0001). In contrast, PNPLA3 protein levels per tissue protein were three-fold higher in AT than the liver (P < .0001) and nine-fold higher when related to whole-body AT and liver tissue masses (P < .0001).

CONCLUSIONS

Contrary to previous assumptions, PNPLA3 is highly abundant in AT. PNPLA3-I148M locally remodels AT TGs to become polyunsaturated as it does in the liver, without affecting lipolysis or composition of serum NEFAs. Changes in AT metabolism do not contribute to NAFLD in PNPLA3-I148M carriers.

Hydroxysteroid 17-β dehydrogenase 13 variant increases phospholipids and protects against fibrosis in nonalcoholic fatty liver disease

Carriers of the hydroxysteroid 17-β dehydrogenase 13 (HSD17B13) gene variant (rs72613567:TA) have a reduced risk of NASH and cirrhosis but not steatosis. We determined its effect on liver histology, lipidome, and transcriptome using ultra performance liquid chromatography-mass spectrometry and RNA-seq. In carriers and noncarriers of the gene variant, we also measured pathways of hepatic fatty acids (de novo lipogenesis [DNL] and adipose tissue lipolysis [ATL] using 2H2O and 2H-glycerol) and insulin sensitivity using 3H-glucose and euglycemic-hyperinsulinemic clamp) and plasma cytokines. Carriers and noncarriers had similar age, sex and BMI. Fibrosis was significantly less frequent while phospholipids, but not other lipids, were enriched in the liver in carriers compared with noncarriers. Expression of 274 genes was altered in carriers compared with noncarriers, consisting predominantly of downregulated inflammation-related gene sets. Plasma IL-6 concentrations were lower, but DNL, ATL and hepatic insulin sensitivity were similar between the groups. In conclusion, carriers of the HSD17B13 variant have decreased fibrosis and expression of inflammation-related genes but increased phospholipids in the liver. These changes are not secondary to steatosis, DNL, ATL, or hepatic insulin sensitivity. The increase in phospholipids and decrease in fibrosis are opposite to features of choline-deficient models of liver disease and suggest HSD17B13 as an attractive therapeutic target.

Prospective randomized controlled trial comparing the efficacy and safety of Roux-en-Y gastric bypass and one-anastomosis gastric bypass (the RYSA trial): trial protocol and interim analysis

INTRODUCTION

There is a lack of prospective studies comparing Roux-en-Y gastric bypass (RYGB) and one-anastomosis gastric bypass (OAGB). Also, the effects of bariatric surgery and weight loss need a deeper understanding through metabolic studies. We describe the trial protocol and interim analysis of a prospective randomized controlled study comparing RYGB and OAGB: the RYSA trial.

MATERIALS AND METHODS

In total, 120 bariatric patients will be randomized between RYGB and OAGB in two academic centers. All patients will be followed up for 10 years with analysis and measurements of weight, comorbidities, blood tests, body composition and questionnaires. Extensive metabolic analyses (mixed meal tests, energy expenditure, biopsies of muscle and subcutaneous fat, urine, saliva and fecal samples) will be carried out in the Obesity Research Unit, University of Helsinki, for all patients treated at the Helsinki University Hospital (80 patients) at baseline, 6 months and 12 months. Bile reflux will be studied for the OAGB group at the Helsinki University Hospital at 6 months with gastroscopy and scintigraphy.

RESULTS

At an interim analysis at 3 months (half-way) through recruitment (30 RYGB and 30 OAGB patients) there have been no deaths and no intensive care unit admittances. One patient in both groups required additional gastroscopy, with anastomosis dilatation in the RYGB group but with no additional intervention in the OAGB group.

CONCLUSION

The trial can be safely carried out. Recruitment is estimated to be complete by the end of 2019.

TRIAL REGISTRATION

Clinical Trials Identifier NCT02882685. Registered on August 30th 2016.

Notum produced by Paneth cells attenuates regeneration of aged intestinal epithelium

A decline in stem cell function impairs tissue regeneration during ageing, but the role of the stem-cell-supporting niche in ageing is not well understood. The small intestine is maintained by actively cycling intestinal stem cells that are regulated by the Paneth cell niche^1,2. Here we show that the regenerative potential of human and mouse intestinal epithelium diminishes with age owing to defects in both stem cells and their niche. The functional decline was caused by a decrease in stemness-maintaining Wnt signalling due to production of Notum, an extracellular Wnt inhibitor, in aged Paneth cells. Mechanistically, high activity of mammalian target of rapamycin complex 1 (mTORC1) in aged Paneth cells inhibits activity of peroxisome proliferator activated receptor α (PPAR-α)³, and lowered PPAR-α activity increased Notum expression. Genetic targeting of Notum or Wnt supplementation restored function of aged intestinal organoids. Moreover, pharmacological inhibition of Notum in mice enhanced the regenerative capacity of aged stem cells and promoted recovery from chemotherapy-induced damage. Our results reveal a role of the stem cell niche in ageing and demonstrate that targeting of Notum can promote regeneration of aged tissues.

Is preoperative gastroscopy necessary before sleeve gastrectomy and Roux-en-Y gastric bypass?

BACKGROUND

Consensus on the necessity of esophagogastroduodenoscopy (EGD) before bariatric surgery is lacking. Recommendations and practices vary by country and unit. Several reports have expressed concerns on gastroesophageal reflux disease (GERD) and its consequences after sleeve gastrectomy (SG) and the risk of leaving a premalignant lesion in the excluded stomach after Roux-en-Y gastric bypass (RYGB).

OBJECTIVES

We explored the number and types of clinically significant findings in preoperative EGDs and how they associate with preexisting GERD-symptoms (SG) and premalignant lesions (RYGB). We also studied how many reoperations were performed due to postoperative GERD in SG-patients.

SETTING

University hospital.

METHODS

We investigated preoperative EGD-findings and gastrointestinal symptoms before bariatric surgery in all patients with a primary bariatric operation in our unit between December 2007 and May 2016.

RESULTS

We performed 1474 operations: 1047 (71.0%) RYGB, 407 (27.6%) SG, and 20 (1.4%) others. One thousand two hundred seventy-five (86.5%) preoperative EGD reports were analyzed: 647 (50.7%) EGDs were completely normal. Altogether, 294 patients (23.0% of total) had a clinically significant finding that was relevant for SG (hiatal hernia, esophagitis, Barrett's esophagus, esophageal dysplasia), 144 (49.0%) of whom reported gastrointestinal symptoms. Twenty patients (1.6%) had a significant finding relevant for RYGB (peptic ulcer, atrophic gastritis, gastrointestinal stromal tumor), and 6 (30%) reported gastrointestinal symptoms. Thirteen (3.2%) SGs were converted into RYGB due to GERD.

CONCLUSIONS

Preoperative EGD is indicated before SG but not before RYGB for asymptomatic patients without a risk for gastric pathology.

Effect of Laparoscopic Sleeve Gastrectomy vs Laparoscopic Roux-en-Y Gastric Bypass on Weight Loss at 5 Years Among Patients With Morbid Obesity: The SLEEVEPASS Randomized Clinical Trial

Importance

Laparoscopic sleeve gastrectomy for treatment of morbid obesity has increased substantially despite the lack of long-term results compared with laparoscopic Roux-en-Y gastric bypass.

Objective

To determine whether laparoscopic sleeve gastrectomy and laparoscopic Roux-en-Y gastric bypass are equivalent for weight loss at 5 years in patients with morbid obesity.

Design, Setting, and Participants

The Sleeve vs Bypass (SLEEVEPASS) multicenter, multisurgeon, open-label, randomized clinical equivalence trial was conducted from March 2008 until June 2010 in Finland. The trial enrolled 240 morbidly obese patients aged 18 to 60 years, who were randomly assigned to sleeve gastrectomy or gastric bypass with a 5-year follow-up period (last follow-up, October 14, 2015).

Interventions

Laparoscopic sleeve gastrectomy (n = 121) or laparoscopic Roux-en-Y gastric bypass (n = 119).

Main Outcomes and Measures

The primary end point was weight loss evaluated by percentage excess weight loss. Prespecified equivalence margins for the clinical significance of weight loss differences between gastric bypass and sleeve gastrectomy were -9% to +9% excess weight loss. Secondary end points included resolution of comorbidities, improvement of quality of life (QOL), all adverse events (overall morbidity), and mortality.

Results

Among 240 patients randomized (mean age, 48 [SD, 9] years; mean baseline body mass index, 45.9, [SD, 6.0]; 69.6% women), 80.4% completed the 5-year follow-up. At baseline, 42.1% had type 2 diabetes, 34.6% dyslipidemia, and 70.8% hypertension. The estimated mean percentage excess weight loss at 5 years was 49% (95% CI, 45%-52%) after sleeve gastrectomy and 57% (95% CI, 53%-61%) after gastric bypass (difference, 8.2 percentage units [95% CI, 3.2%-13.2%], higher in the gastric bypass group) and did not meet criteria for equivalence. Complete or partial remission of type 2 diabetes was seen in 37% (n = 15/41) after sleeve gastrectomy and in 45% (n = 18/40) after gastric bypass (P > .99). Medication for dyslipidemia was discontinued in 47% (n = 14/30) after sleeve gastrectomy and 60% (n = 24/40) after gastric bypass (P = .15) and for hypertension in 29% (n = 20/68) and 51% (n = 37/73) (P = .02), respectively. There was no statistically significant difference in QOL between groups (P = .85) and no treatment-related mortality. At 5 years the overall morbidity rate was 19% (n = 23) for sleeve gastrectomy and 26% (n = 31) for gastric bypass (P = .19).

Conclusions and Relevance

Among patients with morbid obesity, use of laparoscopic sleeve gastrectomy compared with use of laparoscopic Roux-en-Y gastric bypass did not meet criteria for equivalence in terms of percentage excess weight loss at 5 years. Although gastric bypass compared with sleeve gastrectomy was associated with greater percentage excess weight loss at 5 years, the difference was not statistically significant, based on the prespecified equivalence margins.

Trial Registration

clinicaltrials.gov Identifier: NCT00793143.

Long-Term Effect of Gastric Bypass and Sleeve Gastrectomy on Severe Obesity: Do Preoperative Weight Loss and Binge Eating Behavior Predict the Outcome of Bariatric Surgery?

BACKGROUND

Few studies have examined weight loss sustainability after sleeve gastrectomy (SG). The purpose of this study was to determine long-term outcome after SG and gastric bypass (GBP) and learn whether preoperative weight loss and binge eating behavior can be used to predict outcome.

MATERIALS AND METHODS

Together, 257 patients (64 % women) were operated, 163 by GBP and 94 by SG. Binge eating was assessed by binge eating scale (BES) and preoperative weight loss was advised to all, including very low-calorie diet for 5 weeks. Postoperative visits took place at 1 and 2 years, and long-term outcome was at median 5 years (range 2.29-6.85). Multivariate linear regression analysis was used to predict outcome at 2-year and long-term control.

RESULTS

Median age was 48 years, weight 141.1 kg, and BMI 48.2 kg/m(2). Preoperative weight loss was median 4.9 % before GBP and 3.8 % before SG, P = 0.04. Total weight loss at year one was 24.1 % in GBP and 23.7 % in SG (P = 0.40), at year two 24.4 and 23.4 % (P = 0.26), and at long-term control 23.0 and 20.2 % (P = 0.006), respectively. Weight was analyzed in 93, 88, and 89 % of those alive, respectively. BES did not predict weight outcome, but larger preoperative weight loss predicted less postoperative weight loss at 2 years.

CONCLUSION

On long term, weight loss was better maintained after GBP compared with SG. Binge eating behavior was not a significant predictor, but larger preoperative weight loss predicted less postoperative weight loss for the next 2 years.

Obesity/insulin resistance rather than liver fat increases coagulation factor activities and expression in humans

Increased liver fat may be caused by insulin resistance and adipose tissue inflammation or by the common I148M variant in PNPLA3 at rs738409, which lacks both of these features. We hypothesised that obesity/insulin resistance rather than liver fat increases circulating coagulation factor activities. We measured plasma prothrombin time (PT, Owren method), activated partial thromboplastin time (APTT), activities of several coagulation factors, VWF:RCo and fibrinogen, and D-dimer concentration in 92 subjects divided into groups based on insulin sensitivity [insulin-resistant (‘IR’) versus insulin-sensitive (‘IS’)] and PNPLA3 genotype (PNPLA3148MM/MI vs PNPLA3148II). Liver fat content (1H-MRS) was similarly increased in ‘IR’ (13 ± 1 %) and PNPLA3148MM/MI (12 ± 2 %) as compared to ‘IS’ (6 ± 1 %, p < 0.05) and PNPLA3148II (8 ± 1 %, p < 0.05), respectively. FVIII, FIX, FXIII, fibrinogen and VWF:RCo activities were increased, and PT and APTT shortened in ‘IR’ versus ‘IS’, in contrast to these factors being similar between PNPLA3148MM/MI and PNPLA3148II groups. In subjects undergoing a liver biopsy and entirely lacking the I148M variant, insulin-resistant subjects had higher hepatic expression of F8, F9 and FGG than equally obese insulin-sensitive subjects. Expression of pro-inflammatory genes in adipose tissue correlated positively with PT (% of normal), circulating FVIII, FIX, FXI, VWR:RCo and fibrinogen, and expression of anti-inflammatory genes negatively with PT (%), FIX and fibrinogen. We conclude that obesity/insulin resistance rather than an increase in liver fat is associated with a procoagulant plasma profile. This reflects adipose tissue inflammation and increased hepatic production of coagulation factors and their susceptibility for activation.

Supplementary Material to this article is available online at www.thrombosis-online.com.

Impaired hepatic lipid synthesis from polyunsaturated fatty acids in TM6SF2 E167K variant carriers with NAFLD

BACKGROUND

Carriers of the transmembrane 6 superfamily member 2 E167K gene variant (TM6SF2^EK/KK) have decreased expression of the TM6SF2 gene and increased risk of NAFLD and NASH. Unlike common 'obese/metabolic' NAFLD, these subjects lack hypertriglyceridemia and have lower risk of cardiovascular disease. In animals, phosphatidylcholine (PC) deficiency results in a similar phenotype. PCs surround the core of VLDL consisting of triglycerides (TGs) and cholesteryl-esters (CEs). We determined the effect of the TM6SF2 E167K on these lipids in the human liver and serum and on hepatic gene expression and studied the effect of TM6SF2 knockdown on hepatocyte handling of these lipids.

METHODS

Liver biopsies were taken from subjects characterized with respect to the TM6SF2 genotype, serum and liver lipidome, gene expression and histology. In vitro, after TM6SF2 knockdown in HuH-7 cells, we compared incorporation of different fatty acids into TGs, CEs, and PCs.

RESULTS

The TM6SF2^EK/KK and TM6SF2^EE groups had similar age, gender, BMI and HOMA-IR. Liver TGs and CEs were higher and liver PCs lower in the TM6SF2^EK/KK than the TM6SF2^EE group (p<0.05). Polyunsaturated fatty acids (PUFA) were deficient in liver and serum TGs and liver PCs but hepatic free fatty acids were relatively enriched in PUFA (p<0.05). Incorporation of PUFA into TGs and PCs in TM6SF2 knockdown hepatocytes was decreased (p<0.05). Hepatic expression of TM6SF2 was decreased in variant carriers, and was co-expressed with genes regulated by PUFAs.

CONCLUSIONS

Hepatic lipid synthesis from PUFAs is impaired and could contribute to deficiency in PCs and increased intrahepatic TG in TM6SF2 E167K variant carriers.

PROX1 and β-catenin are prognostic markers in pancreatic ductal adenocarcinoma

Background

The Wnt/β-catenin pathway has a key role in regulating cellular processes and its aberrant signaling can lead to cancer development. The role of β-catenin expression in pancreatic ductal adenocarcinoma is somewhat controversial. Transcription factor PROX1 is a target of Wnt/β-catenin signaling and it is involved in carcinogenesis through alterations in its expression. The actions can be either oncogenic or tumor suppressive depending on the tissue. The aim of this study was to investigate PROX1 and β-catenin expression in pancreatic ductal adenocarcinoma (PDAC).

Methods

Expression of PROX1 and β-catenin were evaluated in 156 patients by immunohistochemistry of tissue microarrays. Associations between tumor marker expression and clinicopathological parameters were assessed by the Fischer’s exact-test or the linear-by-linear association test. The Kaplan-Meier method and log-rank test were used for survival analysis. Uni- and multivariate survival analyses were carried out by the Cox regression proportional hazard model.

Results

High PROX1 expression was seen in 74 (48 %) tumors, and high β-catenin expression in 100 (65 %). High β-catenin expression was associated with lower tumor grade (p = 0.025). High PROX1 and β-catenin expression associated significantly with lower risk of death from PDAC in multivariate analysis (HR = 0.63; 95 % CI 0.42–0.95, p = 0.026; and HR = 0.54; 95 % CI 0.35–0.82, p = 0.004; respectively). The combined high expression of PROX1 and β-catenin also predicted lower risk of death from PDAC (HR = 0.46; 95 % CI 0.28–0.76, p = 0.002).

Conclusion

In conclusion, high PROX1 and β-catenin expression were independent factors for better prognosis in pancreatic ductal adenocarcinoma.

Electronic supplementary material

The online version of this article (doi:10.1186/s12885-016-2497-5) contains supplementary material, which is available to authorized users.

The Results of Pancreatic Resections and Long-Term Survival for Pancreatic Ductal Adenocarcinoma: A Single-Institution Experience

OBJECTIVES

Since the early 1990s, low long-term survival rates following pancreatic surgery for pancreatic ductal adenocarcinoma have challenged us to improve treatment. In this series, we aim to show improved survival from pancreatic ductal adenocarcinoma during the era of centralized pancreatic surgery.

METHODS

Analysis of all pancreatic resections performed at Helsinki University Hospital and survival of pancreatic ductal adenocarcinoma patients during 2000-2013 were included. Post-operative complications such as fistulas, reoperations, and mortality rates were recorded. Patient and tumor characteristics were compared with survival data.

RESULTS

Of the 853 patients undergoing pancreatic surgery, 581 (68%) were pancreaticoduodenectomies, 195 (21%) distal resections, 28 (3%) total pancreatectomies, and 49 (6%) other procedures. Mortality after pancreaticoduodenectomy was 2.1%. The clinically relevant B/C fistula rate was 7% after pancreaticoduodenectomy and 13% after distal resection, and the re-operation rate was 5%. The 5- and 10-year survival rates for pancreatic ductal adenocarcinoma were 22% and 14%; for T1-2, N0 and R0 tumors, the corresponding survival rates were 49% and 31%. Carbohydrate antigen 19-9 >75 kU/L, carcinoembryonic antigen >5 µg/L, N1, lymph-node ratio >20%, R1, and lack of adjuvant therapy were independent risk factors for decreased survival.

CONCLUSION

After centralization of pancreatic surgery in southern Finland, we have managed to enable pancreatic ductal adenocarcinoma patients to survive markedly longer than in the early 1990s. Based on a 1.7-million population in our clinic, mortality rates are equal to those of other high-volume centers and long-term survival rates for pancreatic ductal adenocarcinoma have now risen to some of the highest reported.

Podocalyxin Is a Marker of Poor Prognosis in Pancreatic Ductal Adenocarcinoma

Aim of the Study

Podocalyxin-like 1 is a transmembrane glyco-protein whose overexpression associates in many cancers with poor prognosis and unfavorable clinicopathological characteristics. Until now, its prognostic value has never been studied in pancreatic ductal adenocarcinoma (PDAC). The aim of this study was to investigate podocalyxin expression in PDAC by a novel monoclonal antibody and a commercially available polyclonal antibody.

Patients and Materials

With tissue microarrays and immuno-histochemistry, podocalyxin expression evaluation involved 168 PDAC patients. The associa-tions of the podocalyxin tumor expression with clinicopathological variables were explored by Fisher’s exact test and the linear-by-linear test. Survival analyses were by Kaplan-Meier anal-ysis and the Cox proportional hazard model.

Results

The polyclonal antibody revealed membranous podocalyxin expression in 73 (44.0%) specimens and the monoclonal antibody was highly expressed in 36 (21.8%) cases. Membranous expression by the polyclonal antibody was associated with T classification (p=0.045) and perineural invasion (p=0.005), and high expression by the mono-clonal antibody with poor differentiation (p=0.033). High podocalyxin expression associated significantly with higher risk of death from PDAC by both the polyclonal antibody (hazard ratio (HR) = 1.62; 95% confidence interval (CI) 1.12-2.33; p=0.01) and the monoclonal antibody (HR = 2.10, 95% CI 1.38-3.20; p<0.001). The results remained significant in multivariate analysis, adjusted for age, gender, stage, lymph node ratio (≥/< 20%), and perivascular invasion (respectively as HR = 2.03; 95% CI 1.32-3.13, p=0.001; and as HR = 2.36; 95% CI 1.47-3.80, p<0.001).

Conclusion

We found podocalyxin to be an independent factor for poor prognosis in PDAC. To our knowledge, this is the first such report of its prognostic value.

Preoperative biliary decompression preceding pancreaticoduodenectomy with plastic or self-expandable metallic stent

BACKGROUND AND AIMS

The rainage (PBD) prior to pancreaticoduodenectomy (PD) is controversial. If PBD is required, large bore self-expandable metallic stents (SEMS) are thought to maintain better drainage and have fewer postoperative complications than plastic stents. The confirming evidence is scarce. The aim of the study was to compare outcomes of surgery in patients who underwent PBD with SEMS or plastic stents deployed at endoscopic retrograde cholangiopancreatography (ERCP).

MATERIAL AND METHODS

This is a retrospective study of 366 patients having had PD during 2000-2009. Preceding endoscopic PBD was performed in 191 patients and nine had had percutaneous transhepatic drainage (PTD). At the time of operation, 163 patients had a plastic stent and 28 had SEMS. Due to stent exchanges, 176 plastic stents and 29 SEMS were placed in all.

RESULTS AND CONCLUSIONS

The stent failure rate was 7.4% for plastic stents and 3.4% for SEMS (p = 0.697). A bilirubin level under 50 µmol/L was reached by 80% of the patients with plastic stents and by 61% of the patients with SEMS (p = 0.058). A postoperative infection complication and/or a pancreatic fistula was found in 26% while using plastic stents and in 25% using SEMS (p = 1.000). In unstented patients with biliary obstruction, the bile juice was sterile significantly more often than in endoscopically stented patients (100% vs 1%, p < 0.001). When the stented and unstented patients were compared regarding postoperative infection complications, there was no significant difference between the groups (p = 0.365). Plastic stents did not differ from SEMS regarding the stent failure rate, bilirubin level decrease, amount of bacteria in the bile juice, or postoperative complications when used for PBD. The significantly higher price of SEMS suggests their use in selected cases only.

Comparison of short-term outcome of laparoscopic sleeve gastrectomy and gastric bypass in the treatment of morbid obesity: A prospective randomized controlled multicenter SLEEVEPASS study with 6-month follow-up

BACKGROUND AND AIMS

The long-term efficacy of laparoscopic Roux-en-Y gastric bypass in the treatment of morbid obesity has already been demonstrated. Laparoscopic sleeve gastrectomy has shown promising short-term results, but the long-term efficacy is still unclear. The aim of this prospective randomized multicenter study is to compare the results of Roux-en-Y gastric bypass and sleeve gastrectomy.

MATERIAL AND METHODS

A total of 240 morbidly obese patients were randomized to undergo either Roux-en-Y gastric bypass or sleeve gastrectomy. The primary end point of study was weight loss, and the secondary end points were resolution of comorbidities and morbidity. The short-term results at 6 months were analyzed.

RESULTS

The mean excess weight loss at 6 months was 49.2% in the sleeve gastrectomy group and 52.9% in the Roux-en-Y gastric bypass group (p = 0.086). Type 2 diabetes was resolved or improved in 84.3% of patients in the sleeve gastrectomy group and 93.3% in the Roux-en-Y gastric bypass group (p = 0.585). The corresponding results for arterial hypertension were 76.8% and 81.9% (p = 0.707) and for hypercholesterolemia 64.1% and 69.0% (p = 0.485). There was no mortality at 6 months. There was one major complication following sleeve gastrectomy and two after Roux-en-Y gastric bypass (p = 0.531). Eight sleeve gastrectomy patients and 11 Roux-en-Y gastric bypass patients had minor complications (p = 0.403).

CONCLUSION

The short-term results of sleeve gastrectomy and Roux-en-Y gastric bypass regarding weight loss, resolution of obesity-related comorbidities and complications were not different at 6 months.

Circulating triacylglycerol signatures in nonalcoholic fatty liver disease associated with the I148M variant in PNPLA3 and with obesity

We examined whether relative concentrations of circulating triacylglycerols (TAGs) between carriers compared with noncarriers of PNPLA3(I148M) gene variant display deficiency of TAGs, which accumulate in the liver because of defective lipase activity. We also analyzed the effects of obesity-associated nonalcoholic fatty liver disease (NAFLD) independent of genotype, and of NAFLD due to either PNPLA3(I148M) gene variant or obesity on circulating TAGs. A total of 372 subjects were divided into groups based on PNPLA3 genotype or obesity. Absolute and relative deficiency of distinct circulating TAGs was observed in the PNPLA3(148MM/148MI) compared with the PNPLA3(148II) group. Obese and 'nonobese' groups had similar PNPLA3 genotypes, but the obese subjects were insulin-resistant. Liver fat was similarly increased in obese and PNPLA3(148MM/148MI) groups. Relative concentrations of TAGs in the obese subjects versus nonobese displayed multiple changes. These closely resembled those between obese subjects with NAFLD but without PNPLA3(I148M) versus those with the I148M variant and NAFLD. The etiology of NAFLD influences circulating TAG profiles. 'PNPLA3 NAFLD' is associated with a relative deficiency of TAGs, supporting the idea that the I148M variant impedes intrahepatocellular lipolysis rather than stimulates TAG synthesis. 'Obese NAFLD' is associated with multiple changes in TAGs, which can be attributed to obesity/insulin resistance rather than increased liver fat content per se.

Prediction of non-alcoholic fatty-liver disease and liver fat content by serum molecular lipids

AIMS/HYPOTHESIS

We examined whether analysis of lipids by ultra-performance liquid chromatography (UPLC) coupled to MS allows the development of a laboratory test for non-alcoholic fatty-liver disease (NAFLD), and how a lipid-profile biomarker compares with the prediction of NAFLD and liver-fat content based on routinely available clinical and laboratory data.

METHODS

We analysed the concentrations of molecular lipids by UPLC-MS in blood samples of 679 well-characterised individuals in whom liver-fat content was measured using proton magnetic resonance spectroscopy ((1)H-MRS) or liver biopsy. The participants were divided into biomarker-discovery (n = 287) and validation (n = 392) groups to build and validate the diagnostic models, respectively.

RESULTS

Individuals with NAFLD had increased triacylglycerols with low carbon number and double-bond content while lysophosphatidylcholines and ether phospholipids were diminished in those with NAFLD. A serum-lipid signature comprising three molecular lipids ('lipid triplet') was developed to estimate the percentage of liver fat. It had a sensitivity of 69.1% and specificity of 73.8% when applied for diagnosis of NAFLD in the validation series. The usefulness of the lipid triplet was demonstrated in a weight-loss intervention study.

CONCLUSIONS/INTERPRETATION

The liver-fat-biomarker signature based on molecular lipids may provide a non-invasive tool to diagnose NAFLD, in addition to highlighting lipid molecular pathways involved in the disease.

[The effect of gastric sleeve and bypass surgery on the use and costs of medications for type 2 diabetes]

The study group consisted of 96 patients who had used a medication for type 2 diabetes; of them, 33 had undergone gastric sleeve surgery and 63 bypass surgery. Both surgical methods resulted in a similar weight loss among the patients. In follow-up 39 out of 88 patients were able to manage without antidiabetic drugs two years after surgery. The costs of antidiabetic drugs two years after surgery were 79% lower than before the operation. Weight reduction surgery decreases the need for antidiabetic drugs. The greatest cost-efficiency is achieved by targeting weight-loss operations to patients using insulin therapy.

OSBP-related proteins (ORPs) in human adipose depots and cultured adipocytes: evidence for impacts on the adipocyte phenotype

Oxysterol-binding protein (OSBP) homologues, ORPs, are implicated in lipid homeostatic control, vesicle transport, and cell signaling. We analyzed here the quantity of ORP mRNAs in human subcutaneous (s.c.) and visceral adipose depots, as well as in the Simpson-Golabi-Behmel syndrome (SGBS) adipocyte cell model. All of the ORP mRNAs were present in the s.c and visceral adipose tissues, and the two depots shared an almost identical ORP mRNA expression pattern. SGBS adipocytes displayed a similar pattern, suggesting that the adipose tissue ORP expression pattern mainly derives from adipocytes. During SGBS cell adipogenic differentiation, ORP2, ORP3, ORP4, ORP7, and ORP8 mRNAs were down-regulated, while ORP11 was induced. To assess the impacts of ORPs on adipocyte differentiation, ORP3 and ORP8, proteins down-regulated during adipogenesis, were overexpressed in differentiating SGBS adipocytes, while ORP11, a protein induced during adipogenesis, was silenced. ORP8 overexpression resulted in reduced expression of the aP2 mRNA, while down-regulation of adiponectin and aP2 was observed in ORP11 silenced cells. Furthermore, ORP8 overexpression or silencing of ORP11 markedly decreased cellular triglyceride storage. These data identify the patterns of ORP expression in human adipose depots and SGBS adipocytes, and provide the first evidence for a functional impact of ORPs on the adipocyte phenotype.

SLEEVEPASS: a randomized prospective multicenter study comparing laparoscopic sleeve gastrectomy and gastric bypass in the treatment of morbid obesity: preliminary results

BACKGROUND

The long-term efficacy of laparoscopic Roux-en-Y gastric bypass (RYGB) in the treatment of morbid obesity has been demonstrated. Laparoscopic sleeve gastrectomy (SG) as a single procedure has shown promising short-term results, but the long-term efficacy of SG has not yet been demonstrated. The aim of this study was to determine the preliminary 30-day morbidity and mortality of RYGB and SG in a prospective multicenter randomized setting.

METHODS

A total of 240 morbidly obese (BMI = 35-66 kg/m²) patients evaluated by a multidisciplinary team were randomized to undergo either RYGB or SG. There were 117 patients in the RYGB group and 121 in the SG group; two patients had to be excluded after randomization. Both study groups were comparable regarding age, gender, BMI, and comorbidities.

RESULTS

There was no 30-day mortality. The median operating time was significantly shorter in the SG group (66 min vs. 94 min, p < 0.001). All complications were recorded thoroughly. There were 7 (5.8 %) major complications following SG and 11 (9.4 %) after RYGB (p = 0.292). Nine (7.4 %) SG patients and 20 (17.1 %) RYGB patients had minor complications (p = 0.023). The overall morbidity was 13.2 % after SG and 26.5 % after RYGB (p = 0.010). There were three (2.5 %) early reoperations after SG and four (3.3 %) after RYGB (p = 0.719).

CONCLUSIONS

At 30-day analysis SG is associated with a shorter operating time and fewer early minor complications compared to RYGB. There were no significant differences in major complications or early reoperations. Long-term follow-up is required to determine the effect on weight loss, resolution of obesity-related comorbidities, and improvement of quality of life.

[Bariatric surgery and reproductive health]

Obesity is associated with metabolic complications such as insulin-resistance, type 2 diabetes, dyslipidemia, hypertension and polycystic ovary syndrome. Obesity adversely impacts fecundability and IVF outcomes through a variety of mechanisms, however even modest weight loss can improve situation. Pregnancy may be a significant health risk for morbidly obese women (BMI over 40 kg/m2) and fertility treatments are not recommended before weight loss. The fertile age of women is limited, therefore an efficient treatment of obesity should be chosen. For morbid obesity bariatric surgery combined with lifestyle changes is more efficient treatment than conservative treatment alone. Weight loss is associated with significant improvement in many parameters of reproductive function, chance to get pregnant improves and gestational risks decrease.

Epithelial MMP-2 Expression Correlates with Worse Prognosis in Pancreatic Cancer

OBJECTIVE

Matrix metalloproteinases (MMPs) degrade extracellular matrix and are involved in tumor invasion and metastasis in various cancers. In pancreatic cancer, MMP-2 expression is upregulated and correlates with tumor recurrence. The aim of this study was to evaluate the prognostic significance of MMP-2 in pancreatic ductal adenocarcinoma.

METHODS

MMP-2 expression was assessed by immunohistochemistry in 127 patients operated on at Helsinki University Hospital from 1974 to 1998, with expression interpreted separately in epithelial and stromal samples.

RESULTS

Epithelial MMP-2 expression was strong in 5%, moderate in 20%, weak in 25% and negative in 50% of the tumors, with high epithelial MMP-2 expression significantly associated in univariate survival analysis with advanced stage, poor grade and poor survival. Stromal MMP-2 expression was strong in 0%, moderate in 14%, weak in 70% and negative in 16% of the cases, and did not significantly correlate with patient survival.

CONCLUSION

Epithelial MMP-2 correlates with advanced tumor stage and grade, but is not an independent predictor of survival.

Cyclooxygenase-2 expression correlates with poor prognosis in pancreatic cancer

BACKGROUND

Cyclooxygenase-2 (COX-2) overexpression is related to poor outcome in several cancers. COX-2 is upregulated in 42-90% of pancreatic ductal adenocarcinomas and is a potential target for chemotherapy. Earlier studies have not shown the expression of COX-2 to be a prognostic factor in pancreatic cancer.

OBJECTIVE

To evaluate the prognostic value of COX-2 in a series of patients with pancreatic adenocarcinoma.

METHODS

128 patients operated on for pancreatic adenocarcinoma at Helsinki University Central Hospital between 1974 and 1998 provided sections from primary tumours which were immunohistochemically stained with a COX-2-antihuman monoclonal antibody.

RESULTS

Cytoplasmic COX-2 reactivity (>5%) occurred in 46 specimens (36%), correlating neither with age, sex, stage, size, tumour stage, nodal metastases, nor grade. Lack of COX-2 expression correlated with distant metastases (p = 0.026). In univariate survival analysis, COX-2 expression (p = 0.0114), stage (p = 0.0002), grade (p = 0.0001), and age (p = 0.042) had prognostic significance. One, two, and five year survival rates were 51%, 32%, and 8% in the COX-2 negative groups compared with 34%, 5%, and 5% in the COX-2 positive groups (p = 0.011). Prognostic significance was especially high for patients operated on with curative intent (p = 0.004). In multivariate analysis, COX-2 was an independent prognostic factor (hazard ratio = 1.6 (95% confidence interval, 1.1 to 2.3)).

CONCLUSIONS

Expression of COX-2 was associated with poor outcome from pancreatic ductal adenocarcinoma and was independent of tumour stage, grade, or age in multivariate analysis.

Syndecan-1 expression--a novel prognostic marker in pancreatic cancer

OBJECTIVE

Syndecan-1 is a transmembrane receptor that participates in cell-cell and cell-matrix interactions, cell proliferation and cell migration. Expression of syndecan-1 is downregulated in many cancers, but in pancreatic ductal adenocarcinoma it is upregulated.

METHOD

We studied the immunohistochemical expression of syndecan-1 in 144 pancreatic adenocarcinomas and evaluated the prognostic value of syndecan-1 expression. Formalin-fixed, paraffin-embedded specimens were stained with mouse monoclonal antibody B-B4 against human syndecan-1. The epithelial and stromal staining was separately evaluated and compared with patient survival, clinical stage and histological grade.

RESULT

Epithelial immunoreactivity was observed in most of the pancreatic carcinoma samples: in 70 (49%) of the samples the epithelial staining was weak, in 48 (33%) moderate, in 18 (12%) strong and in only 8 (6%) of the samples the epithelial staining was negative. Stromal staining was weak in 24 (17%), moderate in 31 (22%), strong in 11 (8%) and negative in 78 (54%) of the pancreatic carcinoma samples. Lack of stromal expression predicted a better prognosis (p = 0.002; HR 1.7) and it was independent of stage (p = 0.01; HR = 1.5) and grade (p = 0.0004; HR 2.1) in multivariate analysis. Epithelial expression predicted better prognosis for patients that underwent surgery for cure (n = 94, p = 0.03).

CONCLUSION

Stromal syndecan-1 expression is an independent prognostic marker in pancreatic cancer, whereas epithelial syndecan-1 expression predicts better prognosis only in resectable disease.

Tenascin C expression is upregulated in pancreatic cancer and correlates with differentiation

BACKGROUND

Tenascin C is a large, hexameric, extracellular matrix protein that is present during embryonic development but essentially absent in adult tissues. It is involved in remodelling processes, such as wound healing and tumour development. Tissue expression of tenascin C correlates with prognosis in colorectal, cervical, and breast cancer and in carcinoma of the papilla of Vater.

AIM

To study the expression of tenascin C in pancreatic cancer and to compare the staining results with the patients' clinicopathological data.

MATERIAL AND METHODS

Formalin fixed, paraffin wax embedded specimens from 146 patients with pancreatic adenocarcinoma were stained with an anti-tenascin C monoclonal antibody.

RESULTS

Tenascin C immunoreactivity was seen in most samples of pancreatic carcinoma: staining was weak in 72 (49%), moderate in 52 (36%), strong in 10 (7%), and negative in 12 (8%) samples. Tenascin C expression correlated with age (< or = 66 v >66 years) and poor differentiation (grades 1-2 v 3). There was no correlation between tenascin C expression and survival, clinical stage, tumour size, nodal status, distant metastasis, tumour location, or sex.

CONCLUSION

Tenascin C expression was increased in most pancreatic carcinomas, but contrary to the results in other cancers, it is not a prognostic factor in pancreatic cancer.

Loss of p27 Expression Is Associated with Poor Prognosis in Stage I–II Pancreatic Cancer

OBJECTIVE

p27 is a cyclin-dependent kinase inhibitor that prevents progression of the cell cycle from G1 phase. Postranscriptional loss of p27 correlates with poor prognosis in various solid tumors. In pancreatic cancer, the loss of p27 expression has been correlated with high tumor grade and advanced clinical stage, but data on its prognostic value are lacking.

METHOD

In this retrospective study, the association between immunohistochemical p27 expression and prognosis was evaluated in 147 patients with pancreatic cancer using a commercial anti-Kip1/p27 monoclonal antibody.

RESULT

p27 expression was generally low; in 103 of the 147 pancreatic cancer tumors examined, no nuclear staining was observed and in only 5 specimens did more than 50% of the nuclei stain, probably reflecting the aggressive nature of the disease. Loss of p27 expression was associated with poor prognosis in stage I-II pancreatic adenocarcinoma; the 5-year survival for p27 negative patients was 3.6% compared with 20% for p27-positive patients (p = 0.03). In a multivariate survival analysis in patients with stage I-II disease, p27 (HR 1.8) was a significant prognostic factor, independent of grade (RR 2.9). There was no association between p27 and other clinical variables. In conclusion, tissue expression of p27 is a significant predictor of 5-year survival in stage I-II pancreatic adenocarcinoma.

Hypothyroidism among infertile women in Finland

The main aim of this retrospective study was to evaluate the occurrence of hypothyroidism among Finnish women with infertility. For this purpose, the records of 335 women presenting for the first time with infertility at the outpatient clinic of reproductive endocrinology at Turku University Central Hospital during a 3-year period (January 1992 to December 1994) were reviewed. Due to missing data, 36 women were excluded from the analysis. Thyroid function was screened by measuring serum thyroid stimulating hormone (TSH) levels in conjunction with serum prolactin using immunoradiometric assays. Prior to enrolment in the infertility examinations, ten out of 299 women had used thyroxine substitution for primary hypothyroidism. In the TSH screening test, 12 women (4%) exhibited elevated serum TSH levels ranging from 5.7 to 32 mU/l. Three of these cases were previously diagnosed with hypothyroidism and were using an inadequate dose of thyroxine. The prevalence of abnormal TSH levels was highest in the ovulatory dysfunction (6.3%) and unknown infertility (4.8%) groups and lowest in the tubal infertility (2.6%) and male infertility (1.5%) groups, although no statistically significant differences between the groups were observed. Oligo/amenorrhea was present in 101 (34%) women in the whole study population and in eight (67%, p < 0.5) women with elevated serum TSH at screening. The relatively high occurrence of abnormal TSH levels in infertile women with ovulatory dysfunctions or unknown infertility, as well as with oligo/amenorrhea, emphasizes the importance of TSH screening in these patient groups.