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Background: Research implicates inflammation in the vicious cycle between depression and obesity, yet few longitudinal studies exist. The rapid weight loss induced by bariatric surgery is known to improve depressive symptoms dramatically, but preoperative depression diagnosis may also increase the risk for poor weight loss. Therefore, we investigated longitudinal associations between depression and inflammatory markers and their effect on weight loss and clinical outcomes in bariatric patients., Methods: This longitudinal observational study of 85 patients with obesity undergoing bariatric surgery included 41 cases with depression and 44 controls. Before and 6 months after surgery, we assessed depression by clinical interview and measured serum high-sensitivity C-reactive protein (hsCRP) and inflammatory cytokines, including interleukin (IL)-6 and IL-10., Results: Before surgery, depression diagnosis was associated with significantly higher serum hsCRP, IL-6, and IL-6/10 ratio levels after controlling for confounders. Six months after surgery, patients with pre-existing depression still had significantly higher inflammation despite demonstrating similar weight loss to controls. Hierarchical regression showed higher baseline hsCRP levels predicted poorer weight loss ( β = -0.28, p = 0.01) but had no effect on depression severity at follow-up ( β = -0.02, p = 0.9). Instead, more severe baseline depressive symptoms and childhood emotional abuse predicted greater depression severity after surgery ( β = 0.81, p < 0.001; and β = 0.31, p = 0.001, respectively)., Conclusions: Depression was significantly associated with higher inflammation beyond the effect of obesity and other confounders. Higher inflammation at baseline predicted poorer weight loss 6 months after surgery, regardless of depression diagnosis. Increased inflammation, rather than depression, may drive poor weight loss outcomes among bariatric patients.

The aim of this meta-analysis was to assess whether treatment with ursodeoxycholic acid (UDCA) in patients who have undergone bariatric surgery reduces gallstone formation. A systematic literature search was performed using electronic databases (MEDLINE, Embase, CENTRAL, Web of Science, PROSPERO, Google Scholar and the WHO International Clinical Trials Registry platform). RCTs without restrictions on study language, year, status of publication and patient's age were used. Pooled risk ratios were calculated using a random-effects model. Subgroup analyses for drug dose, duration and procedure types were performed. Sensitivity analyses and a summary of findings table were generated to assess the robustness and the level of evidence provided, respectively. Fourteen trials were included (3619 patients, 2292 in UDCA vs 1327 in control group). Procedures included SG, RYGB, OAGB, AGB and Gastroplasty. UDCA dose ranged from 300 to 1200 mg per day. Gallstone formation occurred in 19.3% (8.3% in UDCA vs 38.1% in the control group). UDCA significantly reduced the risk of gallstone formation (14 trials, 3619 patients; RR 0.27, 95% CI 0.18-0.41; P < 0.001). UDCA significantly reduced the risk of symptomatic gallstone disease (6 trials, 2458 patients; RR 0.30, 95% CI 0.21-0.43; P < 0.001). No subgroup difference was found for different doses, duration and type of procedure performed. Oral UDCA treatment significantly reduces the risks of developing gallstones in postoperative bariatric patients from 38 to 8%. The use of 500 to 600 mg UDCA for 6 months is effective and should be implemented in all patients post-bariatric surgery., (© 2023. The Author(s), under exclusive licence to Springer Science+Business Media, LLC, part of Springer Nature.)

Introduction: Ten percent of cirrhotic patients are known to have a high risk of postoperative complications. Ninety percent of bariatric patients suffer from non-alcoholic fatty liver disease (NAFLD), and 50% of them may develop non-alcoholic steatohepatitis (NASH) which can progress to cirrhosis. The aim of this study was to assess whether the presence of cirrhosis at the time of bariatric surgery is associated with an increased rate and severity of short- and long-term cirrhotic complications., Methods: A cohort of 110 bariatric patients, between May 2003 and February 2018, who had undergone liver biopsy at the time of bariatric surgery were reassessed for histological outcome and divided into two groups based on the presence (C, n = 26) or absence (NC, n = 84) of cirrhosis. The NC group consisted of NASH (n = 49), NAFLD (n = 24) and non-NAFLD (n = 11) liver histology. Medical notes were retrospectively assessed for patient characteristics, development of 30-day postoperative complications, severity of complications (Clavien-Dindo (CD) classification) and length of stay. The C group was further assessed for long-term cirrhosis-related outcomes., Results: The C group was older (52 years vs 43 years) and had lower BMI (46 kg/m 2 vs 52 kg/m 2 ) and weight (126 kg vs 145 kg) compared to the NC group (p < 0.05). The C group had significantly higher overall complication rate (10/26 vs 14/84, p < 0.05) and severity of complications (CD class ≥ III, 12% vs 7%, p < 0.05) when compared to the NC group. The length of stay was similar between the two groups (5 days vs 4 days). The C group had significant improvement in model end-stage liver disease scores (7 vs 6, p < 0.01) with median follow-up of 4.5 years (range 2-11 years). There were no long-term cirrhosis-related complications or mortality in our studied cohort (0/26)., Conclusion: Bariatric surgery in cirrhotic patients has a higher risk of immediate postoperative complications. Long-term cirrhosis-related complications or mortality was not increased in this small cohort. Preoperative identification of liver cirrhosis may be useful for risk stratification, optimisation and informed consent. Bariatric surgery in well-compensated cirrhotic patients may be used as an aid to improve long-term outcome.

Background: In bariatric surgery, preoperative very low-calorie diets (VLCD) may better meet the technical demands of surgery by shrinking the liver. However, diets may affect tissue healing and influence bowel anastomosis in an as-yet-undefined manner., Objective: This randomized controlled trial aimed to examine the effect on collagen deposition in wounds in patients on a 4-week VLCD before laparoscopic gastric bypass., Setting: University hospital., Methods: The trial was undertaken in patients undergoing laparoscopic Roux-en-Y gastric bypass, with a control group (n = 10) on normal diet and an intervention group (n = 10) on VLCD (800 kcal) for 4 weeks. The primary outcome measured was expression of collagen I and III in skin wounds, with biopsies taken before and after the diet and 7 days postoperatively as a surrogate of anastomotic healing. Secondary outcome measures included liver volume and fibrosis score, body composition, operating time, blood loss, hospital stay, and complications., Results: Patients in both groups were similar in age, sex, body mass index (53.4 versus 52.8 kg/m 2 ), co-morbidities, liver volume, and body composition. Expression of mature collagen type I was significantly decreased in diet patients compared with controls after 4 weeks of diet and 7 days after surgery. This was significant decrease in liver volume (23% versus 2%, P = .03) but no difference in operating times (129 versus 139 min, P = .16), blood loss, length of stay, or incidence of complications., Conclusions: Preoperative diets shrink liver volume and decrease expression of mature collagen in wounds after surgery. Whether the latter has a detrimental effect on clinical outcomes requires further evaluation., (Crown Copyright © 2018. Published by Elsevier Inc. All rights reserved.)

Background: Obesity surgery mortality risk scoring system (OS-MRS) classifies patients into high, intermediate and low risk, based on age, body mass index, sex and other comorbidities such as hypertension and history of pulmonary embolism. High-risk patients not only have a higher mortality but are more likely to develop post-operative complications necessitating intervention or prolonged hospital stay following bariatric surgery. Endoscopically placed duodenal-jejunal bypass sleeve (Endobarrier) has been designed to achieve weight loss and improve glycaemic control in morbidly obese patients with clinically proven effectiveness. The aim of this study was to assess if pre-operative insertion of endobarrier in high-risk patients can decrease morbidity and length of stay after bariatric surgery., Materials and Methods: Between 2012 and 2014, a cohort of 11 high-risk patients had an Endobarrier inserted (E&BS group) for 1 year prior to definitive bariatric surgery. These patients were compared against a similar group undergoing primary bariatric surgery (PBS group) during same duration. The two groups were matched for age, gender, body mass index, comorbidities, surgical procedure and OS-MRS using propensity score matching. Outcome measures included operative time, morbidity, length of stay, intensive therapy unit (ITU) stay, readmission rate, percentage excess weight loss (%EWL) and percentage total weight loss (%TWL)., Results: Patient characteristics and OS-MRS were similar in both groups (match tolerance 0.1). There was no significant difference in total length of stay, readmission rate, %EWL and %TWL. Operative time, ITU stay, post-operative complications and severity of complications were significantly less in the E&BS group (p < 0.05) with significant likelihood of planned ITU admissions in the PBS group (p < 0.05)., Conclusion: Endobarrier could be considered as a pre bariatric surgical intervention in high-risk patients. It may result in improved post-operative outcomes in high-risk bariatric patients.

Background: Staple line bleeding (SLB) is a common intraoperative complication following resection in laparoscopic sleeve gastrectomy (SG). Opinion is divided on the best measure to deal with SLB which includes expensive reinforcement strategies, suturing the staple line or diathermy. Tranexemic acid is a relatively inexpensive drug known to reduce bleeding in trauma and surgery. The aim of this study was to evaluate whether intraoperative tranexemic acid reduces staple line bleeding., Methods: In this prospective matched comparative study of SG, one cohort of patients was administered tranexemic acid (1 g) after induction and compared to a control group. The primary outcome compared the number of staple line bleeding points requiring intervention intra-operatively. Secondary outcomes included estimated blood loss and operating time. The anaesthetic and thromboprophylaxis protocols were uniform. Operative technique and stapling equipment were identical in all patients., Results: Twenty-five patients were allocated to both the control and treatment arms. Patient characteristics in both groups were similar in age (median 34 vs 43 years), body mass index (median 54.7 vs 52 kg/m(2)), gender distribution (female:male = 20:5) and co-morbidities. The treatment group receiving tranexemic acid, required significantly less number of haemostatic stitches for staple line bleeding (19 vs 46, p < 0.05), incurred less intraoperative blood loss (p < 0.01) and had quicker operating times (median 66 vs 80 min, p < 0.05). There was no difference in morbidity or mortality in both groups., Conclusion: Intraoperative prophylactic tranexemic acid use is a simple and economical option for effectively reducing staple line bleeds leading to significant decrease in operating times.

Background: Bile acids (BA) modulate lipid and glucose metabolism in a feedback loop through production of fibroblast growth factor (FGF) 19 in the terminal ileum. Changes in BA after bariatric surgery may lead to improvements in the metabolic syndrome, including fatty liver disease. This study investigated the relationship between BA and metabolic and inflammatory profiles after laparoscopic sleeve gastrectomy (LSG)., Methods: Patients undergoing LSG had fasting blood samples taken pre-operatively and 6 months post-surgery. Liver injury was measured using cytokeratin (CK) 18 fragments. BA were measured using liquid chromatography tandem-mass spectrometry. FGF-19 was measured using enzyme-linked immunosorbent assay., Results: The study included 18 patients (12 females), with mean age 46.3 years (SEM ± 2.9) and BMI 60.1 kg/m(2) (±2.6). After 6 months, patients lost 39.8 kg (±3.1; p < 0.001). Fourteen patients (78 %) had steatosis. FGF-19 increased from median 128.1 (IQR 89.4-210.1) to 177.1 (121.8-288.9, p = 0.045) at 6 months. Although total BA did not change, primary glycine- and taurine-conjugated BA, cholic acid decreased, and secondary BA, glycine-conjugated urodeoxycholic acid increased over the study period. These changes are associated with reduction in insulin resistance, pro-inflammatory cytokines and CK-18 levels., Conclusions: The profile of individual BA is altered after LSG. These changes occur in the presence of reductions in inflammatory cytokines and markers of liver injury. This study supports evidence from recent animal models that LSG may have an effect on fatty liver through changes in BA metabolism.

Background: The combination of pneumoperitoneum and intraoperative retraction of the left lobe of the liver leads to hepatocellular injury during laparoscopic gastric surgery. Fatty livers are more susceptible to ischaemic insults. This trial investigated whether the antioxidant N-acetylcysteine (NAC) reduced liver injury during laparoscopic sleeve gastrectomy (LSG)., Methods: Patients undergoing LSG were randomised (single blinded) to receive intraoperative NAC infusion or standard anaesthetic treatment. Blood samples were taken before and after surgery (days 0 to 4). Primary endpoints included serum aminotransferases. Secondary measures were C-reactive protein, weight cell count (WCC), cytokines (interleukin 6 and 10) and cytokeratin-18 as markers of apoptosis. Intraoperative liver biopsy samples were assessed using a locally developed injury score., Results: Twenty patients (14 females, mean age 44.5 (SEM ± 2.9) years, mean BMI 60.8 (SEM ± 2.4) kg/m(2)) were recruited (NAC n = 10, control n = 10). The trial was stopped early after a planned interim analysis. Baseline liver function was similar. The peak rise in liver enzymes was on day 1, but levels were not significantly different between the groups. Rates of complications and length of stay were not significantly different. Secondary outcome measures, including white cell count (WCC), cytokines and cytokeratin (CK)-18 fragments, were not different between groups. Liver injury scores did not differ significantly., Conclusions: NAC did not reduce intraoperative liver injury in this small number of patients. The heterogenous nature of the study population, with differences in co-morbidities, body mass index and intraabdominal anatomy, leads to a varied post-operative inflammatory response. Significant hepatocyte injury occurs through both necrosis and apoptosis.

Background: Obesity-related dyslipidaemia comprises hypercholesterolaemia, hypertriglyceridaemia, low HDL-cholesterol and normal to raised LDL-cholesterol levels. 40% of morbidly obese surgical patients have dyslipidaemia. Roux-en-Y gastric bypass (RYGB) surgery has many beneficial metabolic effects, but the full impact on plasma lipids has not been clearly defined., Methods: A systematic review of electronic databases (Ovid; Medline; PubMed; Embase) between 1960 and March 2012 was performed using search terms including the following: obesity surgery, bariatric surgery, gastric bypass, cholesterol, lipids, triglycerides and non-esterified fatty acids. A total of 2442 manuscripts were screened. Papers with paired plasma lipid levels around RYGB surgery were included. Exclusions included the following: editorials, dual publications, n < 10, resulting in 75 papers of relevance. A meta-analysis was performed of the effect of RYGB surgery upon plasma lipids at different time points up to 4 years following surgery, using a random effects model., Results: Paired data were available for 7815 subjects around RYGB surgery for morbid obesity with a baseline BMI 48 kg/m(2) (n = 2331). There was a reduction in plasma total cholesterol and LDL-C from 1 month up to 4 years post-RYGB (p < 0.00001, p < 0.00001). Following RYGB, HDL-C increased from 1 year onwards (p < 0.00001), and triglyceride levels were reduced postoperatively from 3 months up to 4 years (p < 0.00001). NEFA levels were increased at 1 month postoperatively (p = 0.003), but from 3 months onwards did not differ from preoperative levels (p = 0.07)., Conclusions: RYGB surgery reverses the dyslipidaemia of obesity. These findings support the use of RYGB in the management of high cardiovascular risk lipid profiles in morbid obesity.

Single-incision surgery in the morbidly obese patient has not been widely adopted, but remains a popular choice amongst patients. In the bariatric patient, it presents its own surgical challenges with hepatomegaly and increased abdominal adiposity. Here, we present our experience of 275 single-incision laparoscopic gastric bands.Between June 2009 and April 2013, 275 obese patients underwent single-incision laparoscopic adjustable gastric banding through a single incision using a multichannel single port and via a pars flaccida approach. Prospective data collection was undertaken including operating time, additional ports and additional procedures undertaken.In this series, median operative time was 60 (range 34-170) min. An additional port was placed in 15 patients (5%), including two conversions to four-port technique (0.7%). Of these patients (n = 15), the majority were male (p < 0.0001). Reasons for additional port placement included bleeding and anatomical abnormalities. Additional port placement occurred more often within the first 50 cases (5/50, 10% vs 10/225, 4%). An umbilical incision resulted in more wound-related complications than a transverse incision in the upper abdomen (p < 0.001). There were no 30-day mortality and minimal morbidity with two wound infections resulting in band removal.Single-incision laparoscopic adjustable gastric banding can be performed safely with minimal morbidity in the morbidly obese patient, and our technique has a high rate of success for all BMIs. Following 275 single-incision band insertions additional port placements were more commonly required in male patients, BMI >45 and earlier in the learning curve.

Background: Bariatric surgical procedures are classified by their presumed mechanisms of action: restrictive, malabsorptive or a combination of both. However, this dogma is questionable and remains unproven. We investigated post-operative changes in nutrient absorption and transit time following bariatric surgery., Methods: Participants were recruited into four groups: obese controls (body mass index (BMI) >30 kg/m2, n = 7), adjustable gastric banding (n = 6), Roux-en-Y gastric bypass (RYGB, n = 7) and biliopancreatic diversion with duodenal switch (DS, n = 5). Participants underwent sulphasalazine/sulphapyridine tests (oro-caecal transit time); fasting plasma citrulline (functional enterocyte mass); 3 days faecal collection for faecal elastase 1 (FE-1); calprotectin (FCp); faecal fatty acids (pancreatic exocrine function, gut inflammation and fat excretion, respectively); and 5 h D-xylose, L-rhamnose and lactulose test (intestinal absorption and permeability)., Results: Age and gender were not different but BMI differed between groups (p = 0.001). No difference in oro-caecal transit time (p = 0.935) or functional enterocyte mass (p = 0.819) was detected. FCp was elevated post-RYGB vs. obese (p = 0.016) and FE-1 was reduced post-RYGB vs. obese (p = 0.002). Faecal fat concentrations were increased post-DS vs. obese (p = 0.038) and RYGB (p = 0.024) and were also higher post-RYGB vs. obese (p = 0.033). Urinary excretion of D-xylose and L-rhamnose was not different between the groups; however, lactulose/rhamnose ratio was elevated post-DS vs. other groups (all p < 0.02), suggesting increased intestinal permeability., Conclusions: Following RYGB, there are surprisingly few abnormalities or indications of severe malabsorption of fats or sugars. Small bowel adaptation after bariatric surgery may be key to understanding the mechanisms responsible for the beneficial metabolic effects of these operations.

Background: Rhabdomyolysis (RML) is a rare complication of bariatric surgery. A systematic review was performed to identify risk factors and patient outcomes in morbidly obese patients undergoing bariatric surgery who develop RML., Methods: A comprehensive search was performed between January 1990 and March 2012 using relevant MeSH terms. Studies were chosen based on predefined inclusion criteria. RML was defined as a creatine kinase of more than 1,000 IU/L. The parameters assessed included patient characteristics of the RML population, type of bariatric surgery performed, operating time, complications, presentation and diagnosis of RML., Results: Twenty-two studies were analysed which included 11 case reports, two case series, six prospective and three retrospective comparative studies. Overall 145 patients with RML were reported following bariatric surgery. Acute renal failure was found in 20 patients (14 %) and was significantly more likely to occur in patients with postoperative muscle pain (p < 0.05). The mortality rate after renal failure was 25 % (n = 5). In the comparative studies, 87 RML patients were compared with 325 non-RML patients. The RML patients were more likely to be male, had a greater mean body mass index (BMI) (52 vs 48 kg/m(2), p < 0.01) and underwent a longer operation (255 vs 207 min, p < 0.01) compared to non-RML patients., Conclusions: Risk factors of developing RML following bariatric surgery include male gender, elevated BMI and prolonged operating time. Patients with a biochemical diagnosis of RML and postoperative myalgia after bariatric surgery are at increased risk of developing acute renal failure and mortality. These patients must be identified and treated promptly.

Background: As single incision surgery increases in popularity, the feasibility of offering this approach in bariatric surgery is further progression of this surgical technique. With the technical challenges that both operating on the morbidly obese patient and single incision surgery present, we describe our initial experience undertaking 111 single-incision gastric band insertions., Methods: From June 2009 to October 2010, 111 obese patients underwent single-incision laparoscopic adjustable gastric banding through a single transverse incision using a multichannel single port and a pars flaccida technique. Prospective data collection was undertaken, including visual analog scores., Results: In this initial series, the median operative time was 65 minutes (range 34-165). There was 1 conversion to a 5-port laparoscopic technique (.9%), and an additional port was placed in 7 patients (6%). Male patients were more likely to require an additional port (P < .05). The single-incision size ranged from 26 to 45 mm (median 35). At 23 hours postoperatively, the median pain score was 2.5 on a 0-10 visual analog score. On multivariate analysis, pain was found to increase with operation time (P < .001). The median length of stay was 24 hours (range 5.5-48). There was no mortality and minimal morbidity, with 1 wound infection necessitating band removal., Conclusions: Single-incision laparoscopic adjustable gastric banding can be performed safely with minimal morbidity and mortality in the morbidly obese patient, and our technique has a high rate of success. The benefits compared with the traditional laparoscopic approach and long-term outcomes are yet to be established. However, if the intra-abdominal operative time is >60 minutes, one should consider the placement of an additional port, especially in male patients., (Copyright © 2012 American Society for Metabolic and Bariatric Surgery. Published by Elsevier Inc. All rights reserved.)

Background: Single incision laparoscopic bariatric surgery has developed over the last few years, with single incision laparoscopic adjustable gastric banding (SILS-AGB) being performed most commonly. However, there are no randomised controlled trials and few matched studies comparing SILS-AGB to conventional laparoscopic multi-port multiport adjustable gastric banding (LAGB). Our aim was to study any differences in outcome and analgesic requirements between two matched groups of gastric band patients (SILS-AGB and LAGB)., Methods: Between June 2009 and September 2010, 111 patients underwent SILS-AGB and 99 patients underwent LAGB performed by a single surgeon (AGP). Patients were matched for age, sex, weight, BMI and co-morbidities. Forty six SILS-AGB and LAGB patients were included for analysis. Their outcomes were compared for operating times, conversions, analgesia requirements, morbidity and mortality., Results: Patients characteristics between the SILS-AGB and LAGB groups were similar with no differences in their median age (44 vs 47 years), sex (m:f; 7:39 vs 4:42), body mass index (43.1 vs 44.4 kg/m(2)) or co morbidities respectively. In the SILS-AGB group the median operating time (70 min) was not significantly longer than in LAGB group (61.5 min, p = 0.07). However, SILS-AGB patients used less opiates (p < 0.01) than the LAGB patients. There was no difference in morbidity, mortality or readmission rates., Conclusion: SILS-AGB is a safe and feasible option and is comparable with LAGB. Post operative demand for analgesia was significantly less in the SILS-AGB group. Further comparisons of post operative pain and long term outcomes are required; however preliminary results are promising.

Obesity increases the risk of progression of chronic kidney disease (CKD) towards kidney failure and may preclude access to kidney transplantation. Weight loss surgery remains relatively novel in obese patients with CKD, with several studies reporting results using Roux-en-Y bypass and adjustable gastric banding. However, in obese patients with CKD, kidney failure after bypass surgery and gastric band erosion after kidney transplantation have been reported. We present the first report of laparoscopic sleeve gastrectomy (LSG) performed for the treatment of obesity in patients with CKD. Weight loss, blood pressure and lipids, estimated kidney function, surgical complications and adverse events were studied. Nine obese patients with CKD (five of whom were undergoing haemodialysis treatment) underwent LSG, with median body mass index decrease of 8.4 kg/m(2) and excess weight loss of 43.0% after 6 months. Four of the five patients on haemodialysis were added to the kidney transplantation waiting list as a result of weight loss achieved with LSG. Adverse events occurred in three patients: myocardial infarction (one patient), acute kidney injury secondary to dehydration (one patient) and compromised dialysis access (one patient). There was one complication-a gastric leak, detected 7 months after LSG, requiring further surgical intervention and nasojejunal feeding, and no mortality. Our preliminary evidence suggests that LSG is an effective treatment for obesity in patients with CKD. However, there may be additional risk associated with the procedure in patients with CKD, requiring further study.

Iatrogenic nerve injuries have been rarely reported following laparoscopic abdominal surgeries. These can be serious complications with the potential for long-term disability. We present a rare case of bilateral sciatic nerve palsy following laparoscopic sleeve gastrectomy on a super-super-obese male with BMI 78.04 kg/m2. The procedure was completed laparoscopically in 7 hours duration, and in spite of adequate precautions, he developed bilateral sciatic nerve palsy. Nerve conduction studies showed denervation of L5/S1 confirming the diagnosis. The patient showed gradual recovery with physiotherapy, and at 18 months follow-up he was mobilizing without any walking aids, with BMI 47.34 kg/m2. Compressive nerve injuries following prolonged laparoscopic operations should be included in the list of procedural complications, especially in morbidly obese patients where the risk is significantly higher.

Background: Obesity is a major risk factor for the development of endothelial dysfunction. We explored the effect of different degrees of body mass on endothelial function, lipids, systemic inflammation and glucose homeostasis and the effect of surgically-induced weight loss on endothelial function in severely obese humans., Methods: A cross-sectional study of healthy subjects across a wide range of body fatness was performed to characterize the effect of obesity on flow-mediated dilatation (FMD), systemic inflammation, blood pressure and insulin sensitivity. A longitudinal study was performed to assess the effect of bariatric surgery induced weight loss on these parameters. 73 healthy subjects across a wide range of body mass were recruited; of these, 8 underwent bariatric surgery (median BMI 52.2 kg/m2, interquartile range 50.355.9). Endothelial dependent vasodilatation was measured using the brachial artery vasodilatory response to forearm hyperemia assessed using highresolution ultrasonography., Results: Obese subjects were characterised by a complex collection of abnormalities, with hypertension, impaired glucose homeostasis, systemic inflammation and reduced FMD. BMI < or =25 kg/m2 (median FMD 9.7%, interquartile range 6.8-12.2), BMI >30 kg/m2 (median FMD 6.7% 4.8-7.5), P=0.01 comparing FMD in lean and obese subjects. A mean reduction in weight of 23.4 (4.6) kg produced an improvement in FMD from 5.3% (3.87.0) to 10.2% (7.6-13.3), P=0.01., Conclusions: Even moderate obesity leads to endothelial dysfunction. In severely obese subjects, FMD is normalized by weight loss. This improvement in FMD is associated with a decline in inflammatory markers, blood pressure and insulin. The improvement in FMD occurred despite patients remaining significantly obese. These results suggest that an integrated approach to improving endothelial function in obese humans may be necessary.

Background: Obesity surgery has been shown to result not only in sustained weight loss, but also in improvements in psychological morbidity and quality of life. The present study aimed to explore the mechanisms behind the success of surgery and to examine how it might bring about such changes in patients' health status., Methods: Both quantitative and qualitative methods were used. A questionnaire was completed by patients who had undergone bariatric surgery in the past 4 years (n=22) and a matched-group of waiting list controls (n=39). In depth interviews were then carried out with 15 surgical patients., Results: The quantitative study showed that the surgical group weighed less, had more negative experiences of eating and yet reported improved subjective health status using a range of validated tools. The qualitative study provided some insights into this improved health status, with the surgical patients reporting improved energy and self-esteem. The patients also reported a fundamental shift in their relationship with food. In particular, they described changes in their eating behavior and stated that they had a new experience of fullness and a reduction in their hunger. Furthermore, they described how food now had a reduced role in their lives and that the operation had made them feel more in control of their food intake., Conclusion: Post-surgical improvements in health status may not only be a result of the non-specific consequences of surgery brought about by weight loss, but also a result of the specific impact of the surgical procedure itself. By enforcing a reduction in the amount of food that can be eaten, restrictive surgery seems to generate changes in the individuals' relationship to food and may help to re-establish a perception of control over eating behavior.