Oral health profile of postbariatric surgery individuals: A case series.

OBJECTIVES: To describe the oral health profile of individuals who had undergone gastric bypass surgery (GBP) or sleeve gastrectomy (SG) to generate hypotheses for further studies. MATERIAL AND METHODS: Fourteen individuals treated with GBP or SG surgery ≥ 2 years ago and with observed and/or perceived oral problems were recruited to a case series. The documentation included clinical and radiographic examinations, biomedical sampling, and self-reported diet and questionnaires. The results are presented descriptively. RESULTS: The age range was 31 to 66 years and all had a BMI > 25 (range 25.4-44.7). Only four participants were fully dentate. Eleven out of 14 individuals exhibited severe decay. A majority had poor oral hygiene and high bacterial counts. The flow rates of unstimulated saliva were extremely low and hyposalivation was present in ten of the fourteen cases. Most perceived several oral health problems, such as chewing difficulty and tooth hypersensitivity. CONCLUSIONS: Individuals who had undergone GBP or SG surgery had poor clinically diagnosed oral health and perceived oral health problems. Longitudinal studies are needed to monitor the patients' oral health, from before bariatric surgery to long-term postoperatively.

Sleeve gastrectomy and Roux-en-Y gastric bypass in the treatment of type 2 diabetes. Two-year results from a Swedish multicenter randomized controlled trial.

BACKGROUND: Obesity is a world-wide epidemic and it is a risk factor for type 2 diabetes (T2D). Few randomized controlled studies have compared the 2 most common surgical procedures, Roux-en-Y gastric bypass (RYGB) and sleeve gastrectomy (SG) in the treatment of obese patients with T2D. OBJECTIVES: To compare diabetes remission rates (glycosylated hemoglobin ≤6.0%, without diabetes medications) in obese T2D patients (body mass index, 35-50) undergoing RYGB or SG. SETTING: Three University Hospital clinics and 1 Regional Hospital in Sweden. METHODS: Forty-nine patients with T2D were included. Twenty-five were randomized to RYGB and 24 to SG. There was no difference between groups regarding patient characteristics, duration of T2D, overall usage of antidiabetic medications, or glycosylated hemoglobin levels. All patients (100%) completed 1-year follow-up and 47 (95.9%) 2-year follow-up. RESULTS: Remission of T2D was not significantly different between the RYGB and SG, reaching 44% and 46% (n = 25 and n = 24, respectively, P = .897, power = .80) at 1 year, and 48% and 55% (n = 25 and n = 22, respectively, P = .654) at 2 years of follow-up. Similarly, mean glycosylated hemoglobin was improved in both groups at 1 and 2 years, with no significant differences between the groups (RYGB baseline versus 1 yr; mean ± standard deviation: 7.9 ± 1.5 versus 5.8 ± .6%, P < .0001; versus 2 yr: 5.9 ± .7%, P < .0001; SG baseline versus 1 yr: 8.2 ± 1.9 versus 5.9 ± .7%, P < .0001; versus 2 yr: 5.9 ± 1.1%, P < .0001). Total weight loss was not different but percentage excess weight loss was higher after RYGB compared with SG both at 1 and 2 years; mean ± standard deviation: 78 ± 22 versus 60 ± 22%, and 76 ± 24 versus 54 ± 21%, respectively (P < .01 for both). Waist circumference also decreased significantly more in the RYGB group. CONCLUSIONS: Despite superior excess weight loss after RYGB, T2D remission rates did not differ significantly between RYGB and SG after 2 years. Long-term follow-up data are needed to define the role of SG in the treatment of patients with obesity and T2D.

Design and baseline data in the BAriatic surgery SUbstitution and Nutrition study (BASUN): a 10-year prospective cohort study.

BACKGROUND: There is still a lack of knowledge on long-term effects of surgical and non-surgical weight-lowering treatments. BASUN is a prospective study with 10 years of follow-up that will observe the effects and consequences of surgical and medical treatment of obesity. The aims are to cover areas where data on long-term outcomes are lacking, e.g., nutritional deficiencies, substance abuse, psychiatric health, as well as patient-reported outcomes. METHODS: BASUN is a cohort study that recruited study persons with obesity (BMI ≥ 35 kg/m2) referred to the Regional Obesity Centre of Region Västra Götaland. The interventions were Roux-en-Y gastric bypass (RYGB) or Sleeve gastrectomy (SG), or 12 months of structured, multi-professional medical treatment (MT), including very low energy diet, followed by diet and pharmaceutical treatment. The study is not randomized, but based on patients preferences and multidisciplinary assessments. The study persons are examined at baseline, 2, 5, and 10 years with blood tests, measurements and questionnaires. The recruitment period lasted from May 2015 to November 2017. RESULTS: One thousand one hundred twenty-seven patients were included (74% female). Three hundred eighty-two patients were accepted for medical treatment, 589 for surgical treatment (388 RYGB and 201 SG) and 156 patients left the study without treatment, leaving a final study population of 971 patients. There were slight differences between the treatment groups with regards to age and BMI. Pharmaceutical treatments, level of education, smoking and marital status were not significantly different between the groups. CONCLUSION: This study will follow 971 obese subjects in clinical practice treated with the best surgical or medical methods currently available. It has the potential to evaluate outcomes usually not reported in short-term studies, and to assist in identifying factors that are of importance for the choices of treatment. The main limitations are non-randomization and differences in baseline characteristics. The large number of participants and the length of the prospective follow-up are major strengths of the study. BASUN is designed to identify both early and late benefits and adverse events of treatment of obesity. TRIAL REGISTRATION: This trial was prospectively registered on March 03, 2015; NCT03152617.

Oral Health-Related Quality of Life After Gastric Bypass Surgery.

OBJECTIVE: The aim was to examine how individuals treated for obesity with gastric bypass (GBP) surgery perceived their oral health and oral health-related quality of life (OHRQoL). METHOD: All individuals in one Swedish region who had undergone GBP surgery (n = 1182) were sent a postal questionnaire 2 years after surgery. The questionnaire comprised items on sociodemographics, oral symptoms and the Oral Health Impact Profile-49 to assess the OHRQoL. RESULTS: The mean age was 47.6 years with 75% females, response rate 55.3%. The self-perceived oral health was rated low by 45% of the respondents. Gender differences were seen, for instance, regarding hypersensitive teeth (men 18.8%, women 30.8%, p = 0.003). Nine out of ten reported at least one oral impact experienced sometimes, fairly or very often, according to the Oral Health Impact Profile-49 (OHIP-49). The mean additive OHIP-49 score was 30.3 (SD 36.1). The associations between self-reported oral health and OHRQoL were consistent throughout. Tooth hypersensitivity generated an OR of 2.28 (95% CI 2.28-8.46) of having ≥ 2 impacts on OHRQoL. CONCLUSION: A large proportion of individuals having undergone GBP surgery reported problems with their oral health and impacts on their OHRQoL, indicating a need for medical and dental staff-surgeons and general practitioners as well as other health professionals-to offer oral health promotion and prevention measures.

Fracture Risk After Gastric Bypass Surgery: A Retrospective Cohort Study.

Gastric bypass surgery constitutes the most common and effective bariatric surgery to treat obesity. Gastric bypass leads to bone loss, but fracture risk following surgery has been insufficiently studied. Furthermore, the association between gastric bypass and fracture risk has not been studied in patients with diabetes, which is a risk factor for fracture and affected by surgery. In this retrospective cohort study using Swedish national databases, 38,971 obese patients undergoing gastric bypass were identified, 7758 with diabetes and 31,213 without. An equal amount of well-balanced controls were identified through multivariable 1:1 propensity score matching. The risk of fracture and fall injury was investigated using Cox proportional hazards and flexible parameter models. Fracture risk according to weight loss and degree of calcium and vitamin D supplementation 1-year postsurgery was investigated. During a median follow-up time of 3.1 (interquartile range [IQR], 1.7 to 4.6) years, gastric bypass was associated with increased risk of any fracture, in patients with and without diabetes using a multivariable Cox model (hazard ratio [HR] 1.26; 95% CI, 1.05 to 1.53; and HR 1.32; 95% CI, 1.18 to 1.47; respectively). Using flexible parameter models, the fracture risk appeared to increase with time. The risk of fall injury without fracture was also increased after gastric bypass. Larger weight loss or poor calcium and vitamin D supplementation after surgery were not associated with increased fracture risk. In conclusion, gastric bypass surgery is associated with an increased fracture risk, which appears to be increasing with time and not associated with degree of weight loss or calcium and vitamin D supplementation following surgery. An increased risk of fall injury was seen after surgery, which could contribute to the increased fracture risk. © 2018 American Society for Bone and Mineral Research.

Biliopancreatic Diversion is associated with greater increases in energy expenditure than Roux-en-Y Gastric Bypass.

OBJECTIVE: The greater weight loss achieved following Biliopancreatic Diversion with Duodenal Switch (BPDS) versus Roux-en-Y Gastric Bypass (RYGB) has been attributed to the malabsorptive effects of BPDS. Increased weight loss after BPDS could also be underpinned by larger increases in energy expenditure. Hypothetically, the more radical reconfiguration of the small intestine in BPDS could result in an accentuated increase in meal associated thermogenesis (MAT). DESIGN: Female subjects (baseline mean age 40 years, mean BMI-55kg/m2) were assessed four years after randomization to BPDS (n = 6) or RYGB (n = 6). Energy expenditure (EE) and respiratory quotient (RQ) were measured by indirect calorimetry over 24 hours. A detailed protocol allowed for discrimination of basal metabolic rate (BMR), fasting EE and MAT as components of total energy expenditure (TEE) normalised for total and lean tissue by dual-energy x-ray absorptiometry. RESULTS: Median weight loss at follow-up was 1.5-fold higher following BPDS relative to RYGB, resulting in respective median BMIs of 29.5 kg/m2 (21.7 to 36.7) after BPDS and 37.8 kg/m2 (34.1 to 45.7) after RYGB (p = 0.015). The BPDS group had a lower fat:lean ratio compared to the RYGB group (p = 0.009). Overall 24-hour TEE adjusted for total tissue was higher in the BPDS group, as were BMR, fasting EE and MAT (all p<0.05). Differences between RYGB and BPDS in BMR and TEE were nullified when normalised for lean mass. Postprandial RQ increased significantly but to a similar extent in both groups. CONCLUSION: Enhanced and prolonged MAT and lower fat:lean mass ratios after BPDS may explain relative increases in total energy expenditure as compared to RYGB.

Urinary sodium excretion after gastric bypass surgery.

BACKGROUND: Gut-kidney signaling is implicated in sodium homeostasis and thus blood pressure regulation. Roux-en-Y gastric bypass (RYGB) surgery for morbid obesity confers a pronounced and long-lasting blood pressure lowering effect in addition to significant weight loss. OBJECTIVES: We set out to establish whether RYGB is associated with an intrinsic change in urinary sodium excretion that may contribute to the reported blood pressure lowering effects of the procedure. SETTING: University hospital METHODS: Five female patients (age range: 28-50 yr) without metabolic or hypertensive co-morbidities were included in a study involving four 24-hour residential visits: once before surgery and 10 days, 3 months, and 20 months after surgery. Creatinine and sodium were measured in fasting plasma samples and 24-hour urine samples and creatinine clearance, estimated glomerular filtration rate, and indices of urinary sodium excretion were calculated. Fasting and 60-minute postprandial blood samples from each study day were assayed for pro-B-type natriuretic peptide (NT-proBNP). RESULTS: Increases in weight-normalized urinary sodium excretion of up to 2.3-fold in magnitude occurred at 20 months after surgery. Median fractional excretion of sodium at 20 months was double that seen before surgery. Fasting NT-proBNP levels were stable or increased (1.5- to 5-fold). Moreover, a small postprandial increase in NT-proBNP was observed after surgery. CONCLUSIONS: Renal fractional excretion of sodium is increased after RYGB. A shift toward increased postoperative basal and meal associated levels of NT-proBNP coincides with increased urinary sodium excretion. The data support a working hypothesis that an enhanced natriuretic gut-kidney signal after RYGB may be of mechanistic importance in the blood pressure lowering effects of this procedure.

[Energy restriction and adherence required for weight loss without surgery]. / Viktminskning utan kirurgi kräver energirestriktion och följsamhet - Ger minskat nyinsjuknande i diabetes och förbättrade kardiovaskulära riskfaktorer, visar litteraturgenomgång.

Energy restriction and adherence required for weight loss without surgery Non-surgical weight loss treatment has not been shown to reduce mortality or cardiovascular morbidity, but can prevent diabetes mellitus and improves cardiovascular risk factors. For weight loss, energy restriction is fundamental and can lead to an average 2 to 20 kg loss over 6 to 12 months. Pharmacological treatment, behaviour therapy, physical activity and weight loss advice through web sites and smartphone applications and combinations in addition to energy restriction can contribute to further, but relatively limited weight loss up to 30 months. Adherence to the treatment is necessary for both weight loss and long-term weight loss maintenance.

Dumping symptoms is triggered by fat as well as carbohydrates in patients operated with Roux-en-Y gastric bypass.

BACKGROUND: Dumping syndrome after Roux-en-Y gastric bypass (RYGB) is traditionally associated with the consumption of refined carbohydrates, but the role of dietary fat is unclear. OBJECTIVES: This study compares symptoms after consumption of a carbohydrate-rich or fat-rich beverage to determine perceived symptoms, glycemic control, and pulse rate. SETTING: University hospital. METHODS: We assessed perceived symptoms (Sigstad's Dumping Index) and glycemic control (P-glucose and S-insulin) as well as autonomic nervous system activity (reflected by arterial pulse rate) after a standardized liquid meal test (440 kcal/300 mL carbohydrates [CARB] or fat [FAT]) in a randomized crossover blinded setting. Blood samples were drawn before and 1, 15, 30, and 60 minutes after finishing each meal and the area under the curve (AUC) was calculated. RESULTS: Twelve patients 42±10 months after undergoing RYGB were studied. AUC differed between drinks for glucose (P = .003) and insulin (P = .005). Pulse rate increased more after CARB than after FAT (P = .01). AUC for perceived symptoms in the Sigstad's Dumping Index were similar after meals (P = .79), yet the pattern of type of symptoms differed. CONCLUSION: In patients with RYGB, a meal with predominant fat content resulted in as much perceived dumping symptoms as a carbohydrate-profiled meal. As expected, an increase in glucose and insulin levels were found only after carbohydrate intake and the pulse rise was more pronounced for carbohydrates than fat. Dietary counseling in patients undergoing RYGB should address dietary fat as well as traditional information about carbohydrates to avoid dumping symptoms.

Elevated fasting and postprandial C-terminal telopeptide after Roux-en-Y gastric bypass.

Background Roux-en-Y gastric bypass increases circulating bile acid concentrations, known mediators of postprandial suppression of markers of bone resorption. Long-term data, however, indicate that Roux-en-Y gastric bypass confers an increased risk of bone loss on recipients. Methods Thirty-six obese individuals, median age 44 (26-64) with median body mass index at baseline of 42.5 (40.4-46) were studied before and 15 months after Roux-en-Y gastric bypass. After an overnight fast, patients received a 400 kcal mixed meal. Blood samples were collected premeal then at 30-min periods for 120 min. Pre and postmeal samples were analysed for total bile acids, parathyroid hormone and C-terminal telopeptide. Results Body weight loss post Roux-en-Y gastric bypass was associated with a median 4.9-fold increase in peak postprandial total bile acid concentration, and a median 2.4-fold increase in cumulative food evoked bile acid response. Median fasting parathyroid hormone, postprandial reduction in parathyroid hormone and total parathyroid hormone release over 120 min remained unchanged after surgery. After surgery, median fasting C-terminal telopeptide increased 2.3-fold, peak postprandial concentrations increased 3.8-fold and total release was increased 1.9-fold. Conclusions Fasting and postprandial total bile acids and C-terminal telopeptide are increased above reference range after Roux-en-Y gastric bypass. These changes occur in spite of improved vitamin D status with supplementation. These results suggest that post-Roux-en-Y gastric bypass increases in total bile acids do not effectively oppose an ongoing resorptive signal operative along the gut-bone axis. Serial measurement of C-terminal telopeptide may be of value as a risk marker for long-term skeletal pathology in patients post Roux-en-Y gastric bypass.

Roux-en-Y Gastric Bypass and Vertical Banded Gastroplasty Induce Long-Term Changes on the Human Gut Microbiome Contributing to Fat Mass Regulation.

Bariatric surgery is currently the most effective procedure for the treatment of obesity. Given the role of the gut microbiota in regulating host metabolism and adiposity, we investigated the long-term effects of bariatric surgery on the microbiome of patients randomized to Roux-en-Y gastric bypass or vertical banded gastroplasty and matched for weight and fat mass loss. The two surgical procedures induced similar and durable changes on the gut microbiome that were not dependent on body mass index and resulted in altered levels of fecal and circulating metabolites compared with obese controls. By colonizing germ-free mice with stools from the patients, we demonstrated that the surgically altered microbiota promoted reduced fat deposition in recipient mice. These mice also had a lower respiratory quotient, indicating decreased utilization of carbohydrates as fuel. Our results suggest that the gut microbiota may play a direct role in the reduction of adiposity observed after bariatric surgery.

Roux-en-Y Gastric Bypass Surgery Increases Respiratory Quotient and Energy Expenditure during Food Intake.

OBJECTIVE: The mechanisms determining long-term weight maintenance after Roux-en-Y gastric bypass (RYGB) remain unclear. Cross sectional studies have suggested that enhanced energy expenditure (EE) may play a significant role and the aim of this study was to reveal the impact of RYGB on each major component constituting total EE. DESIGN: Six obese female subjects, without other co-morbidities, were assessed before and at 10 days, 3 and 20 months after RYGB. Indirect calorimetry in a metabolic chamber was used to assess 24 h EE at each study visit. Other measurements included body composition by DEXA, gut hormone profiles and physical activity (PA) using high sensitivity accelerometers. RESULTS: Median Body Mass Index decreased from 41.1 (range 39.1-44.8) at baseline to 28 kg/m2 (range 22.3-30.3) after 20 months (p<0.05). Lean tissue decreased from 55.9 (range 47.5-59.3) to 49.5 (range 41.1-54.9) kg and adipose tissue from 61 (range 56-64.6) to 27 (range 12-34.3) kg (both p<0.05). PA over 24 h did not change after surgery whereas 24 h EE and basal metabolic rate (BMR) decreased. EE after a standard meal increased after surgery when adjusted for total tissue (p<0.05). After an initial drop, RQ (respiratory quotient) had increased at 20 months, both as measured during 24 h and after food intake (p<0.05). CONCLUSION: RYGB surgery up-regulates RQ and EE after food intake resulting in an increased contribution to total EE over 24 h when corrected for total tissue.

Preoperative assessment of gut hormones does not correlate to weight loss after Roux-en-Y gastric bypass surgery.

BACKGROUND: Roux-en-Y gastric bypass (RYGB) surgery is an effective and frequently used surgical treatment for severe obesity. Postoperative weight loss varies markedly, but biomarkers to predict weight loss outcomes remain elusive. Levels of the satiety gut hormones glucagon like peptide-1 (GLP-1) and peptide YY (PYY) are attenuated in obese patients but elevated after RYGB surgery. We aimed to evaluate the preoperative responses of GLP-1 and PYY to a standard meal as a predictor of weight loss after RYGB surgery. We hypothesized that weak satiety gut hormone responses preoperatively, would predict poor weight loss after RYGB surgery. METHODS: Preoperatively 43 patients (F = 25/M = 18) had GLP-1 and PYY measured in the fasting state and at 30-minute intervals over 180 minutes after a standard 400 kcal mixed meal. Weight loss was assessed at weight stability after surgery (mean 16.2 mo [CI 15.516.9]). RESULTS: Body mass index decreased from 44.0 kg/m(2) (CI 42.2-45.7) before surgery to 30.3 kg/m(2) (CI 28.4-32.2) after surgery (P<.001). Preoperative GLP-1 and PYY responses to food intake; as delta value between fasting and maximum as well as total responses during 180 minutes did not correlate to total weight loss (GLP-1; rho = .060 and rho = -.089, PYY; rho = -.03 and rho = -.022, respectively) or to excess weight loss % (GLP-1; rho = .051 and rho = -.064, PYY; rho = -.1 and rho = -.088, respectively). CONCLUSION: Preoperative responses of GLP-1 and PYY to a 400 kcal mixed meal do not correlate to postoperative weight loss after RYGB surgery for morbid obesity.

More symptoms but similar blood glucose curve after oral carbohydrate provocation in patients with a history of hypoglycemia-like symptoms compared to asymptomatic patients after Roux-en-Y gastric bypass.

BACKGROUND: Laparoscopic Roux-en-Y gastric bypass (LRYGB) is an effective treatment for obesity through altering several physiologic mechanisms. Some patients experience symptoms suggestive of hypglycemia after LRYGB, but whether these symptoms always are associated with low blood glucose are unclear. The objective of this study was to investigate the correlation between symptoms suggestive of hypglycemia, plasma glucose levels and gut hormones involved in glycemic control. METHODS: Eight LRYGB patients with hypglycemia-like symptoms (SY) and 8 patients with no hypglycemia-like symptoms (ASY) ingested a liquid carbohydrate meal. Insulin, plasma-glucose, glucagon-like peptide 1 (GLP-1) and glucagon were measured intermittently 180 minutes postprandially. In addition, pulse rate, blood pressure and symptoms were assessed. RESULTS: Plasma glucose at 120 min was lower in the ASY mean (95% CI) 2.4 (1.6,3.3) mmol/L (43.2 mg/dL) compared to the SY group 3.0 (3.1,4.6) mmol/L (54.6 mg/dL), (P = .050). The ASY group had larger reduction in plasma glucose than the SY group from pre- to 120 min postmeal -2.2 (-2.8,-1.7) mmol/L (-39.6 mg/dL) versus -1.1 (-1.7,-0.4) mmol/L (-19.8 mg/dL), (P = .011). The concentrations of insulin, GLP-1 and glucagon did not differ significantly between groups. Blood pressure was similar between groups, but the AUC for pulse rate was higher in the SY than ASY group 13009 (11148,14870) versus 11569 (10837,12300) beats/180 minutes, (P = .038). The SY group reported more symptoms than the ASY group, AUC for Sigstad scale 60 to 180 minutes was 970 (-274,1667) for SY versus 170 for ASY (-39,379), (P = .028). CONCLUSION: Patients with a history of symptoms suggestive of hypglycemia after LRYGB neither demonstrated lower plasma glucose nor greater insulin response compared to asymptomatic patients in response to a liquid carbohydrate meal, but perceived more symptoms.

Enhanced fasting and post-prandial plasma bile acid responses after Roux-en-Y gastric bypass surgery.

OBJECTIVE: Exogenous bile acid (BA) administration is associated with beneficial metabolic effects very similar to those seen after Roux-en-Y gastric bypass (RYGB) surgery. Re-routing of bile into a biliopancreatic limb with simultaneous exclusion of food occurs after RYGB, with subsequent increased fasting plasma BAs. The study assessed fasting and post-prandial plasma BA response before and 15 months after RYGB. MATERIAL AND METHODS: The prospective study recruited 63 obese individuals (43 females), aged 43 (36-56) [median (IQR)] years. Blood samples were collected before and every 30 min for 120 min after a standard 400 kcal meal. Fasting and post-prandial plasma BAs, glucagons like peptide-1 (GLP-1), -tyrosine (PYY), fasting C-reactive protein (CRP), glucose and insulin were measured and homeostasis model assessment-insulin resistance (HOMA-IR) was calculated. RESULTS: Following RYGB, body mass index, CRP, fasting glucose and HOMA-IR decreased; 43.7 (39.3-49.2) kg/m(2) to 29.2 (25.1-35.0) kg/m(2), 7.9 (4.1-11.9) mg/L to 0.4 (0.2-1.0) mg/L, 5.5 (5.0-6.0) mmol/L to 4.6 (4.3-4.9) mmol/L and 5.9 (3.5-9.2) to 1.7 (1.1-2.2), respectively, all P < 0.001. Fasting total BAs, GLP-1 and PYY increased after RYGB; 1.69 (0.70-2.56) µmol/L to 2.43 (1.23-3.82) µmol/L (P = 0.02), 6.8 (1.5-15.3) pmol/L to 17.1 (12.6-23.9) pmol/L (P < 0.001) and 4.0 (1.0-7.1) pmol/L to 15.2 (10.0-28.3) pmol/L (P < 0.001), respectively. The area under the curve for post-prandial total BAs, total glycine-conjugated BAs, GLP-1 and PYY were greater after RYGB; 486 (312-732) µmol/L/min versus 1012 (684-1921) µmol/L/min, 315 (221-466) µmol/L/min versus 686 (424-877) µmol/L/min, 3679 (3162-4537) pmol/L/min versus 5347 (4727-5781) pmol/L/min and 1887 (1423-2092) pmol/L/min versus 3296 (2534-3834) pmol/L/min, respectively, all P < 0.0001. CONCLUSION: Weight loss following RYGB is associated with an increase in post-prandial plasma BA response due to larger amounts of glycine-conjugated BAs. This suggests up regulation of BA production and conjugation after RYGB.

Higher circulating bile acid concentrations in obese patients with type 2 diabetes.

BACKGROUND: Bile acids (BAs) play an important role in releasing incretin hormones via the enteroendocrine L-cell surface TGR5 receptors. The aim of this study was to investigate the difference in BA concentration at baseline and in response to a meal stimulus between type 2 diabetes mellitus (T2DM) and a matched normoglycaemic group. MATERIALS AND METHODS: A cross-sectional study of 12 patients with known T2DM and 12 matched normoglycaemic controls compared BA fractions after an overnight fast and following a standard meal. RESULTS: The T2DM group had higher baseline glucose (P < 0.001), but baseline total BA, total glycine conjugated BAs (GCBA) and total taurine conjugated BA (TCBA) were similar between both groups. The T2DM group compared to the normoglycaemic group had a higher post-prandial peak change in total BAs 4.28 (3.51-5.38) µmol/L vs. 0.88 (0.60-1.57) µmol/L (P < 0.001) and peak total GCBA 2.77 (1.07-4.19) µmol/L vs. 0.94 (0.34-1.15) µmol/L (P < 0.0001), but similar peak total TCBA 0.36 (0.02-0.76) µmol/L vs. 0.08 (0.04-0.22) µmol/L (P=0.91). CONCLUSION: The post-prandial bile acid response is elevated in obese patients with T2DM compared to matched normoglycaemic individuals.

Increased postprandial energy expenditure may explain superior long term weight loss after Roux-en-Y gastric bypass compared to vertical banded gastroplasty.

BACKGROUND AND AIMS: Gastric bypass results in greater weight loss than Vertical banded gastroplasty (VBG), but the underlying mechanisms remain unclear. In addition to effects on energy intake the two bariatric techniques may differentially influence energy expenditure (EE). Gastric bypass in rats increases postprandial EE enough to result in elevated EE over 24 hours. This study aimed to investigate alterations in postprandial EE after gastric bypass and VBG in humans. METHODS: Fourteen women from a randomized clinical trial between gastric bypass (n = 7) and VBG (n = 7) were included. Nine years postoperatively and at weight stability patients were assessed for body composition and calorie intake. EE was measured using indirect calorimetry in a respiratory chamber over 24 hours and focused on the periods surrounding meals and sleep. Blood samples were analysed for postprandial gut hormone responses. RESULTS: Groups did not differ regarding body composition or food intake either preoperatively or at study visit. Gastric bypass patients had higher EE postprandially (p = 0.018) and over 24 hours (p = 0.048) compared to VBG patients. Postprandial peptide YY (PYY) and glucagon like peptide 1 (GLP-1) levels were higher after gastric bypass (both p<0.001). CONCLUSIONS: Gastric bypass patients have greater meal induced EE and total 24 hours EE compared to VBG patients when assessed 9 years postoperatively. Postprandial satiety gut hormone responses were exaggerated after gastric bypass compared to VBG. Long-term weight loss maintenance may require significant changes in several physiological mechanisms which will be important to understand if non-surgical approaches are to mimic the effects of bariatric surgery.

Gastric bypass reduces fat intake and preference.

Roux-en-Y gastric bypass is the most effective therapy for morbid obesity. This study investigated how gastric bypass affects intake of and preference for high-fat food in an experimental (rat) study and within a trial setting (human). Proportion of dietary fat in gastric bypass patients was significantly lower 6 yr after surgery compared with patients after vertical-banded gastroplasty (P = 0.046). Gastric bypass reduced total fat and caloric intake (P < 0.001) and increased standard low-fat chow consumption compared with sham controls (P < 0.001) in rats. Compared with sham-operated rats, gastric bypass rats displayed much lower preferences for Intralipid concentrations > 0.5% in an ascending concentration series (0.005%, 0.01%, 0.05%, 0.1%, 0.5%, 1%, 5%) of two-bottle preference tests (P = 0.005). This effect was demonstrated 10 and 200 days after surgery. However, there was no difference in appetitive or consummatory behavior in the brief access test between the two groups (P = 0.71) using similar Intralipid concentrations (0.005% through 5%). Levels of glucagon-like peptide-1 (GLP-1) were increased after gastric bypass as expected. An oral gavage of 1 ml corn oil after saccharin ingestion in gastric bypass rats induced a conditioned taste aversion. These findings suggest that changes in fat preference may contribute to long-term maintained weight loss after gastric bypass. Postingestive effects of high-fat nutrients resulting in conditioned taste aversion may partially explain this observation; the role of GLP-1 in mediating postprandial responses after gastric bypass requires further investigation.

Gut hormones as mediators of appetite and weight loss after Roux-en-Y gastric bypass.

OBJECTIVE: To evaluate the physiologic importance of the satiety gut hormones. BACKGROUND: Controversy surrounds the physiologic role of gut hormones in the control of appetite. Bariatric surgery remains the most effective treatment option for obesity, and gut hormones are implicated in the reduction of appetite and weight after Roux-en-Y gastric bypass. METHODS: We correlated peptide YY (PYY) and glucagon-like peptide 1 (GLP-1) changes within the first week after gastric bypass with changes in appetite. We also evaluated the gut hormone responses of patients with good or poor weight loss after gastric bypass. Finally, we inhibited the gut hormone responses in gastric bypass patients and then evaluated appetite and food intake. RESULTS: Postprandial PYY and GLP-1 profiles start rising as early as 2 days after gastric bypass (P < 0.05). Changes in appetite are evident within days after gastric bypass surgery (P < 0.05), and unlike other operations, the reduced appetite continues. However, in patients with poor weight loss after gastric bypass associated with increased appetite, the postprandial PYY and GLP-1 responses are attenuated compared with patients with good weight loss (P < 0.05). Inhibiting gut hormone responses, including PYY and GLP-1 after gastric bypass, results in return of appetite and increased food intake (P < 0.05). CONCLUSION: The attenuated appetite after gastric bypass is associated with elevated PYY and GLP-1 concentrations, and appetite returns when the release of gut hormones is inhibited. The results suggest a role for gut hormones in the mechanism of weight loss after gastric bypass and may have implications for the treatment of obesity.