A systems biology approach to understand gut microbiota and host metabolism in morbid obesity: design of the BARIA Longitudinal Cohort Study.

INTRODUCTION: Prevalence of obesity and associated diseases, including type 2 diabetes mellitus, dyslipidaemia and non-alcoholic fatty liver disease (NAFLD), are increasing. Underlying mechanisms, especially in humans, are unclear. Bariatric surgery provides the unique opportunity to obtain biopsies and portal vein blood-samples. METHODS: The BARIA Study aims to assess how microbiota and their metabolites affect transcription in key tissues and clinical outcome in obese subjects and how baseline anthropometric and metabolic characteristics determine weight loss and glucose homeostasis after bariatric surgery. We phenotype patients undergoing bariatric surgery (predominantly laparoscopic Roux-en-Y gastric bypass), before weight loss, with biometrics, dietary and psychological questionnaires, mixed meal test (MMT) and collect fecal-samples and intra-operative biopsies from liver, adipose tissues and jejunum. We aim to include 1500 patients. A subset (approximately 25%) will undergo intra-operative portal vein blood-sampling. Fecal-samples are analyzed with shotgun metagenomics and targeted metabolomics, fasted and postprandial plasma-samples are subjected to metabolomics, and RNA is extracted from the tissues for RNAseq-analyses. Data will be integrated using state-of-the-art neuronal networks and metabolic modeling. Patient follow-up will be ten years. RESULTS: Preoperative MMT of 170 patients were analysed and clear differences were observed in glucose homeostasis between individuals. Repeated MMT in 10 patients showed satisfactory intra-individual reproducibility, with differences in plasma glucose, insulin and triglycerides within 20% of the mean difference. CONCLUSION: The BARIA study can add more understanding in how gut-microbiota affect metabolism, especially with regard to obesity, glucose metabolism and NAFLD. Identification of key factors may provide diagnostic and therapeutic leads to control the obesity-associated disease epidemic.

Gastrointestinal symptoms and food intolerance 2 years after laparoscopic Roux-en-Y gastric bypass for morbid obesity.

BACKGROUND: Laparoscopic Roux-en-Y gastric bypass (LRYGB) is an effective treatment for morbid obesity, but might aggravate gastrointestinal complaints and food intolerance. The long-term prevalence of these symptoms has not been well studied. METHODS: In a cross-sectional study, all patients who underwent primary LRYGB from May to October 2012 were approached 2 years after surgery to complete a general health questionnaire, the Gastrointestinal Symptom Rating Scale (GSRS), and a food intolerance questionnaire. The results were compared with those for a control group of morbidly obese patients. RESULTS: A total of 249 patients were included for analysis, representing a response rate of 93·9 per cent. Mean(s.d.) total weight loss was 30·8(8·7) per cent. The total mean GSRS score was higher in patients who had LRYGB (median 2·19 versus 1·75 in unoperated patients; P < 0·001); the difference in symptoms of indigestion was most notable (P < 0·001). Food intolerance for specific products was reported by 70·7 (95 per cent c.i. 64·8 to 76·0) per cent of the postoperative patients, for a median of 4 foods. There was a positive correlation between food intolerance and score on the GSRS. There was no correlation between either food intolerance or the total mean GSRS score and weight loss, but there was a correlation between weight loss and abdominal pain. CONCLUSION: At 2 years after surgery, patients undergoing LRYGB for morbid obesity have more gastrointestinal complaints than obese controls. Food intolerance is a common side-effect of LRYGB independent of degree of weight loss or the presence of other abdominal symptoms.

Tissue-specific inflammation and insulin sensitivity in subjects with obesity.

Obesity is associated with low-grade inflammation and insulin resistance (IR). The contribution of adipose tissue (AT) and hepatic inflammation to IR remains unclear. We conducted a study across three cohorts to investigate this relationship. The first cohort consists of six women with normal weight and twenty with obesity. In women with obesity, we found an upregulation of inflammatory markers in subcutaneous and visceral adipose tissue, isolated AT macrophages, and the liver, but no linear correlation with tissue-specific insulin sensitivity. In the second cohort, we studied 24 women with obesity in the upper vs lower insulin sensitivity quartile. We demonstrated that several omental and mesenteric AT inflammatory genes and T cell-related pathways are upregulated in IR, independent of BMI. The third cohort consists of 23 women and 18 men with obesity, studied before and one year after bariatric surgery. Weight loss following surgery was associated with downregulation of multiple immune pathways in subcutaneous AT and skeletal muscle, alongside notable metabolic improvements. Our results show that obesity is characterised by systemic and tissue-specific inflammation. Subjects with obesity and IR show a more pronounced inflammation phenotype, independent of BMI. Bariatric surgery-induced weight loss is associated with reduced inflammation and improved metabolic health.

The effects of laparoscopic Roux-en-Y gastric bypass and one-anastomosis gastric bypass on glycemic control and remission of type 2 diabetes mellitus: study protocol for a multi-center randomized controlled trial (the DIABAR-trial).

BACKGROUND: Metabolic surgery induces rapid remission of type 2 diabetes mellitus (T2DM). There is a paucity of high level evidence comparing the efficacy of the laparoscopic Roux-en-Y gastric bypass (RYGB) and the laparoscopic one-anastomosis gastric bypass (OAGB) in glycemic control. Also, the mechanisms that drive the conversion of T2DM in severe obese subjects to euglycemia are poorly understood. METHODS: The DIABAR-trial is an open, multi-center, randomized controlled clinical trial with 10 years follow-up which will be performed in 220 severely obese patients, diagnosed with T2DM and treated with glucose-lowering agents. Patients will be randomized in a 1:1 ratio to undergo RYGB or OAGB. The primary outcome is glycemic control at 12 months follow-up. Secondary outcome measures are diverse and include weight loss, surgical complications, psychologic status and quality of life, dietary behavior, gastrointestinal symptoms, repetitive bloodwork to identify changes over time, glucose tolerance and insulin sensitivity as measured by mixed meal tests, remission of T2DM, presence of non-alcoholic fatty liver disease/non-alcoholic steatohepatitis in liver biopsy, oral and fecal microbiome, cardiovascular performance, composition of bile acids, and the tendency to develop gallstones. DISCUSSION: The DIABAR-trial is one of the few randomized controlled trials primarily aimed to evaluate the glycemic response after the RYGB and OAGB in severe obese patients diagnosed with T2DM. Secondary aims of the trial are to contribute to a deeper understanding of the mechanisms that drive the remission of T2DM in severe obese patients by identification of microbial, immunological, and metabolic markers for metabolic response and to compare complications and side effects of RYGB and OAGB. TRIAL REGISTRATION: ClinicalTrials.gov NCT03330756 ; date first registered: October 13, 2017.

Long-term Emergency Department Visits and Readmissions After Laparoscopic Roux-en-Y Gastric Bypass: a Systematic Review.

PURPOSE: There is considerable evidence on short-term outcomes after laparoscopic Roux-en-Y gastric bypass (LRYGB), but data on long-term outcome is scarce, especially on postoperative emergency department (ED) visits and readmissions. We aim to systematically review evidence on the incidence, indications, and risk factors of ED visits and readmissions beyond 30 days after LRYGB. MATERIALS AND METHODS: A systematic search in PubMed, Scopus, Embase.com , Cochrane Library, and PsycINFO was performed. All studies reporting ED visits and readmissions > 30 days after LRYGB, with ≥ 50 patients, were included. PRISMA statement was used and the Newcastle-Ottawa Scale for quality assessment. RESULTS: Twenty articles were included. Six studies reported on ED visits (n = 2818) and 19 on readmissions (n = 276,543). The rate of patients with an ED visit within 90 days after surgery ranged from 3.9 to 32.6%. ED visits at 1, 2, and 3 years occurred in 25.6%, 30.0%, and 31.1% of patients. Readmissions within 90 days and at 1-year follow-up ranged from 4.1 to 20.5% and 4.75 to 16.6%, respectively. Readmission was 29% at 2 years and 23.9% at 4.2 years of follow-up. The most common reason for ED visits and readmissions was abdominal pain. CONCLUSION: Emergency department visits and readmissions have been reported in up to almost one in three patients on the long-term after LRYGB. Both are mainly indicated for abdominal pain. The report on indications and risk factors is very concise. A better understanding of ED visits and readmissions after LRYGB is warranted to improve long-term care, in particular for patients with abdominal pains.

Randomized clinical trial of an enhanced recovery after surgery programme versus conventional care in laparoscopic Roux-en-Y gastric bypass surgery.

Background: Enhanced recovery after surgery (ERAS) programmes have led to a decreased duration of hospital stay in several surgical fields, but have not been fully tested in patients undergoing laparoscopic Roux-en-Y gastric bypass (LRYGB) for obesity. This study aimed to investigate an ERAS programme versus standard care in these patients. Methods: Between January 2013 and July 2014, patients undergoing LRYGB were randomized to ERAS or conventional care. The primary outcome was functional hospital stay, defined as the time between end of surgery and when predefined discharge criteria (pain adequately controlled, fever and postoperative nausea and vomiting (PONV) absent, full liquid diet tolerated, mobilized and feeling fit for discharge) were met. Secondary outcomes were total length of hospital stay, 30-day complication and mortality rates, duration of surgery, time spent on the recovery ward and health-related quality of life. Results: A total 220 patients were randomized to ERAS (110 patients) or conventional (110) care. Patients in the ERAS group had shorter functional hospital stay (17·4 versus 20·5 h; P < 0·001), quicker pain control, tolerated liquid diet earlier, had earlier control of PONV, mobilized sooner and were comfortable with discharge sooner than those receiving conventional care. Total length of hospital stay, duration of surgery, time spent on the recovery ward, health-related quality of life, complication and readmission rates did not differ between the study groups. There were no deaths. Conclusion: Patients under ERAS care recovered faster after LRYGB surgery than those receiving conventional care, with no increase in readmission and postoperative morbidity rates. Registration number: NTR3853 (http://www.trialregister.nl/).

Acquired mutations in the MXR/BCRP/ABCP gene alter substrate specificity in MXR/BCRP/ABCP-overexpressing cells.

A disparity was noted in the transport of rhodamine 123 among nine MXR/BCRP/ABCP-overexpressing cells studied; all demonstrated mitoxantrone transport, whereas only two effluxed rhodamine 123. When the MXR/BCRP/ABCP gene was sequenced in the cell lines studied, differences were noted at amino acid 482, predicted to be at the start of the third transmembrane domain. Sequencing genomic DNA revealed wild-type MXR/BCRP/ABCP to have an arginine at position 482. Cells having a threonine or glycine at position 482 were able to efflux rhodamine 123, whereas cells having an arginine were not. A vaccinia virus expression system confirmed that rhodamine as well as doxorubicin efflux is observed with R482T or R482G but not with the wild-type R482; all three MXR/BCRP/ABCP forms transported mitoxantrone. Cross-resistance studies suggest that, compared with wild-type MXR/BCRP/ABCP, cells having an R482T mutation have higher anthracycline resistance, whereas an R482G mutation seems to confer relatively less resistance to SN-38 and topotecan. These results suggest that amino acid 482 has a crucial role in MXR/BCRP/ABCP function and that mutation of a single amino acid residue significantly changes substrate specificity, thus altering the drug resistance phenotype.

Relationships between type 2 diabetes remission after gastric bypass and different weight loss metrics: arguments against excess weight loss in metabolic surgery.

BACKGROUND: Percentage excess weight loss (%EWL) outcome of bariatric surgery is distorted by deviations in baseline body mass index (BMI). It has been reported that this can lead to false conclusions, most likely because bariatric weight loss in fact is baseline-BMI independent. OBJECTIVES: If the metabolic effect of bariatric surgery is baseline-BMI independent as well, could %EWL also lead to false conclusions on metabolic surgery? SETTING: Bariatric Center of Excellence, general hospital, Netherlands. METHODS: Retrospective analysis of 1-year outcome of all consecutive primary gastric bypass patients with type 2 diabetes (T2DM). Metabolic outcome (glycated hemoglobin [HbA1c], T2DM medication) was compared with bariatric outcome (weight loss) using 3 different metrics: %EWL, the most popular weight loss metric among bariatric surgeons; percentage (total) weight loss (%WL), most commonly used by nonsurgical professionals; and percentage alterable weight loss (%AWL), the only metric rendering weight loss outcome independent of baseline BMI. Metabolic success (HbA1c≤6.0%, T2DM remission) was compared with different definitions of bariatric success (≥50 %EWL, BMI<35 kg/m(2), %AWL percentiles; Mann-Whitney test; P< .05). RESULTS: Until May 2014, 2001 patients underwent primary laparoscopic Roux-en-Y gastric bypass (LRYGB), of whom 449 had T2DM with baseline BMI 43.3 kg/m(2), mean 1.6 number of T2DM medication and HbA1c 7.5%. At 1 year 95% follow-up, with BMI 30.5 kg/m(2), 52.1% T2DM remission, 86.9% HbA1c<7.0%, and 63.6% without T2DM medication. No significant differences in T2DM outcome and weight loss were found with different baseline BMI, except for %EWL (P<.001). Weight loss was significantly better with better T2DM outcome, but for %EWL contradictory relationships were found in baseline-BMI subgroups. T2DM outcome was not less successful for patients with<50 %EWL. CONCLUSION: In T2DM patients, weight loss after gastric bypass does not depend on BMI, HbA1c, or T2DM medication at baseline. The popular %EWL metric and the 50 %EWL success criterion are problematic in comparing bariatric and metabolic outcome of gastric bypass surgery. They should be abandoned. The %WL metric is the best and most commonly used alternative, whereas %AWL is ideal for selected logistics in bariatric research. Weight loss percentiles are best suited for defining bariatric success in metabolic surgery.

A functional assay for detection of the mitoxantrone resistance protein, MXR (ABCG2).

The fluorescent compounds rhodamine 123, LysoTracker Green DMD-26, mitoxantrone, and BODIPY-prazosin were used with the antagonist fumitremorgin C (FTC) in order to develop functional assays for the half-transporter, MXR/BCRP/ABCP1. A measure of FTC-inhibitable efflux was generated for each compound in a series of MXR-overexpressing drug-selected cell lines and in ten unselected cell lines which were used to determine if the four fluorescent compounds were sensitive enough to detect the low MXR levels found in drug-sensitive cell lines. FTC-inhibitable efflux of mitoxantrone and prazosin was found in four of the ten cell lines, SF295, KM12, NCI-H460, and A549, and low but detectable levels of MXR mRNA were also observed by Northern analysis in these cells. FTC-inhibitable mitoxantrone and prazosin efflux in both selected and unselected cell lines was found to correlate well with MXR levels as determined by Northern blotting, r(2)=0.89 and r(2)=0.70 respectively. In contrast, rhodamine and LysoTracker were not able to reliably detect MXR. Cytotoxicity assays performed on two of the four unselected cell lines confirmed increased sensitivity to mitoxantrone in the presence of FTC. FTC was found to be a specific inhibitor of MXR, with half-maximal inhibition of MXR-associated ATPase activity at 1 microM FTC. Short term selections of the SF295, KM12, NCI-H460 and A549 cell lines in mitoxantrone resulted in a small but measurable increase in MXR by both Northern blot and functional assay. These studies show that flow cytometric measurement of FTC-inhibitable mitoxantrone or prazosin efflux is a sensitive and specific method for measuring the function of the MXR half-transporter in both selected and unselected cell lines.

Copper analysis of nail clippings. An attempt to differentiate between normal children and patients suffering from cystic fibrosis.

From 39 normal children and 36 patients, suffering from cystic fibrosis (C/F), the copper content of finger nail clippings and toe nail clippings were determined. From this study it can be concluded that, although the patients with cystic fibrosis (C/F) have a higher copper content, the determination of copper in nail samples cannot be used in order to differentiate between normal children and patients. Also higher mean copper concentrations were found in finger nail clippings in comparison with toe nails. This difference was significant for patients with cystic fibrosis.

Transient cerebellar mutism after posterior fossa surgery in children.

Cerebellar mutism has been reported after surgery for posterior fossa tumors in children and, rarely, in adults. The pathogenesis of this syndrome remains unclear, and controversy exists regarding whether it is a purely psychogenic disorder or an organic syndrome. The anatomical substrate for the mutism also remains unknown. We encountered five cases of postoperative transient cerebellar mutism in a consecutive series of 63 children with posterior fossa tumors. These cases were analyzed and compared with the patients without mutism to find predictive factors for the occurrence of mutism, with the hope of elucidating further the pathophysiological mechanism. The most significant finding was the presence in all cases of a period of cerebellar dysarthria after resolution of the muteness. We, therefore, believe that cerebellar mutism is an extreme form of dysarthria, rather than a real cognitive deficit or a psychological disturbance.

Validating the alterable weight loss (AWL) metric with 2-year weight loss outcome of 500 patients after gastric bypass.

BACKGROUND: Percentage alterable weight loss (AWL) is the only known weight loss metric independent of the initial body mass index (BMI), a unique feature ideal for use in weight loss research. AWL was not yet validated. The aim of the study is to validate the AWL metric and to confirm advantages over the excess weight loss (EWL) metric. METHODS: AWL is tested with 2-year weight loss results of all primary laparoscopic Roux-en-Y gastric bypass patients operated in our hospital. Nadir results of patients with higher and lower initial BMI are compared (Mann-Whitney; p < 0.05) using outcome metrics BMI, percentage weight loss (WL), EWL, and AWL, for the whole group, for each gender, and for <40 and ≥40 years separately. RESULTS: Five-hundred patients (401 female) out of 508 (98.4 %) had 2-year follow-up. Of all four metrics, only AWL rendered results not significantly influenced by initial BMI. The AWL outcome is initial BMI independent for both genders and age-groups. Results also confirm that women and younger patients had significantly higher AWL outcome. CONCLUSION: The recently developed AWL metric, defined as 100% × (initialBMI - BMI) / (initialBMI - 13), is now validated. In contrast to the well-known outcome metrics BMI, EWL, and WL, the AWL metric is independent of the initial BMI. It should replace the misleading EWL metric for comparing weight loss results in bariatric research and for expressing the effectiveness of bariatric procedures. This effectiveness does not act on the total body mass, or on the excess part, but on the alterable part, defined as BMI minus 13 kg/m(2) for all adult patients, female, male, young, and old.

The impact of surgical complications as a main risk factor for venous thromboembolism: a multicenter study.

BACKGROUND: Studies suggest that postoperative complications are a risk factor for venous thromboembolism (VTE) after bariatric surgery. Knowledge of factors associated with a higher risk of VTE after bariatric surgery may be essential to select patients who may benefit from either prolonged or intensified thrombosis prophylaxis. The aim of this study is to determine the relationship between postoperative complications and VTE after bariatric surgery and other classical risk factors. METHODS: A retrospective multicenter case-control study was performed in patients who had bariatric surgery between January 2008 and September 2011. VTE until 6 months after surgery was registered, and patients were contacted to ascertain the results. For every case of VTE after surgery, 6 control patients were selected who were matched for gender, age, participating center and type of surgery. Risk factors for VTE before and after surgery and postoperative complications were registered. RESULTS: A total of 2,064 surgeries were included. In 12 patients, VTE occurred within 6 months after bariatric surgery (incidence 0.58 %, 95 % confidence interval (CI) = 0.25-0.93). There was a strong association of complications after surgery (cases 91.7 %, controls 15.3 %, odds ratio (OR) 61.0; 95 % CI = 7.1-521.3) or intensive care admission (cases 50.0 %, controls 11.1 %, OR = 8.0; 95 % CI = 2.1-30.8) with VTE. The majority of postoperative complications were anastomotic leak, abdominal abscess, and infection. We could not detect an association between classical thrombosis risk factors and postoperative VTE. CONCLUSIONS: The incidence of VTE is low after bariatric surgery using thrombosis prophylaxis. However, there is a strong association between postoperative complications and VTE. These patients may benefit from more intensive thrombosis prophylaxis.

Hepatic and peripheral insulin sensitivity do not improve 2 weeks after bariatric surgery.

OBJECTIVE: Bariatric surgery has rapid metabolic effects on glucose metabolism before the occurrence of clinically significant weight loss. This suggests an acute effect of the surgery itself, e.g., resulting from bypassing the nutrient flow from the proximal gastrointestinal tract. Rapid effects of Roux-en-Y gastric bypass surgery (RYGB) on glucose metabolism were defined. DESIGN AND METHODS: Glucose metabolism and total triglyceride hydrolysis in the basal state and during a hyperinsulinemic euglycemic clamp using stable isotopes 2 weeks were studied before and after RYGB. RESULTS: Eighteen pre-menopausal women scheduled for RYGB were included. 2 weeks after RYGB median weight loss was 7.8 kg. Basal insulin and glucose levels decreased after surgery. Endogenous glucose production (EGP) was lower after surgery. In addition, insulin levels were lower during the clamp after surgery, suggesting enhanced clearance. Hepatic and peripheral insulin sensitivity did not change. Free fatty acid (FFA) levels increased after surgery both in the basal state and during the first step of the clamp. Total triglyceride hydrolysis did not change in the basal state and tended to be higher during hyperinsulinemia. CONCLUSIONS: Within 2 weeks, RYGB reduces basal EGP as well as insulin and glucose levels without an acute beneficial effect on hepatic or peripheral insulin sensitivity. The latter may be explained by higher rates of lipolysis and exposure to FFA induced by the hypocaloric state.