Salt taste after bariatric surgery and weight loss in obese persons.

Background. Little is known about the perception of salty taste in obese patients, especially after bariatric surgery. Therefore, the aim of this study was to analyse possible differences in salt detection thresholds and preferences for foods differing in salt content in obese persons before and after bariatric surgery with weight loss compared to non-obese individuals. Methods. Sodium chloride detection thresholds and liking for cream soups with different salt concentrations were studied with established tests. Moreover, a brief salt food questionnaire was assessed to identify the usage and awareness of salt in food. Results. The results showed similar mean sodium chloride detection thresholds between non-obese and obese participants. After bariatric surgery a non-significant increase in the salt detection threshold was observed in the obese patients (mean ± SD: 0.44 ± 0.24 g NaCl/L before OP vs. 0.64 ± 0.47 g NaCl/L after OP, p = 0.069). Cream soup liking between controls and obese patients were not significantly different. However, significant sex specific differences were detected with the tested women not liking the soups (p < 0.001). Results from the food questionnaire were similar between the groups. Conclusion. No differences between non-obese persons and obese patients were shown regarding the salt detection threshold. However, due to highly significant differences in soup liking, sex should be taken into consideration when conducting similar sensory studies.

Surgical Elimination of the Gastric Digestion by Roux-en-Y Gastric Bypass Impacts on Food Sensitisation-a Pilot Study.

BACKGROUND: Impairment of gastric digestion due to pH elevation increases the risk for food allergy induction. As patients after Roux-en-Y gastric bypass (RYGB) surgery have lower gastric acidity and less gastric gland secretion, we aimed to analyse in a prospective study the effect of limiting gastric digestion capacity by surgical intervention on the immune response towards allergens. METHODS: Nine patients undergoing RYGB surgery for morbid obesity and one control patient having undergone surgery for treatment of an incisional hernia were enrolled in the study. Before and 1, 3, 6, 9 and 12 months after surgery, blood was collected for analysis of specific IgE antibodies, and patients were subjected to skin prick testing with 16 food and 18 aeroallergens. RESULTS: Skin prick test results revealed an increase of positive reactions indicating sensitisations towards the tested food and aeroallergens in 77.8 and 88.9 % of the patients, respectively, after surgical elimination of gastric digestion. These results were in line with elevated titers of food- and aeroallergen-specific IgE antibodies in 7 out of 9 (7/9) and 5/9 patients, respectively, after RYGB surgery. Serum cytokine levels revealed a mixed response for IFN-γ and were mostly beneath detection limit for IL-4. CONCLUSION: A change of IgE reactivity pattern occurred after impairment of gastric digestion due to surgical elimination underlining the important gastric gatekeeping function during oral sensitisation. Even though this study indicates an increased allergy risk for gastric bypass patients, further studies are needed to investigate in-depth the immunological changes associated with RYGB surgery.

Hypoglycemia after Roux-En-Y gastric bypass: detection rates of continuous glucose monitoring (CGM) versus mixed meal test.

BACKGROUND: Neuroglucopenic hypoglycemia might be an underestimated threat for roux-en-Y gastric bypass (RYGB) patients leading to fatigue, syncope, seizures or even accidental deaths. Different measurements can assess hypoglycemia such as a finger-stick glucometer, an Oral Glucose Tolerance Test, a Mixed Meal-Test (MMT) or, as introduced recently, continuous glucose monitoring (CGM). SETTING: University Hospital, Austria. METHODS: To assess the incidence of hypoglycemic episodes under real life conditions, 5-day CGM was performed in a series of 40 patients at a mean of 86 months after RYGB. The detection rates were compared to a mixed meal-test. RESULTS: CGM detected hypoglycemic episodes of <55 mg/dL or <3.05 mmol/L in 75% of the patients, while MMT indicated hypoglycemia in 29% of the patients. CGM also detected nocturnal hypoglycemic episodes in 15 (38%) of the patients. A mean of 3±1 hypoglycemic episodes per patient with a mean duration of 71±25 minutes were observed by CGM. CONCLUSIONS: Assessed under real life conditions by CGM, post-RYGB hypoglycemia was found more frequently than expected. CGM revealed hypoglycemic episodes in 75% of the patients while MMT had a lower detection rate. Thus, CGM may have a role for screening but also for the evaluation of dietary modifications, drug therapy or surgical intervention for hypoglycemia after RYGB.

Post-Bariatric Body-Contouring Surgery: Fewer Procedures, Less Demand, and Lower Costs.

BACKGROUND: Paralleling the growth of bariatric surgery, the demand for post-bariatric body-contouring surgery is increasing and placing additional burdens on already strained health care systems. In Austria, medically necessary body contouring is covered by public health care. In a sample of 622 women, we assessed the proportion of patients that underwent post-bariatric surgery at least 2 years after gastric bypass. METHODS: Former bariatric patients were asked whether they had undergone post-bariatric surgery or were planning to do so by structured telephone interviews. For patients who had undergone body contouring, the degree of satisfaction with the results was inquired. Costs for bariatric and post-bariatric procedures were assessed. RESULTS: Of 622 patients, 93 (14.9 %) had undergone body contouring and 68 (10.9 %) considered a procedure, while 454 (73 %) definitely stated that they did not want plastic surgery. Cost coverage was declined in 7 patients (1.1 %). Plastic procedures (n = 101) included 65 abdominoplasties, 25 lower body lifts without thigh lifts, 7 brachioplasties, and 4 minor procedures. Forty-nine patients were very satisfied with the results, 28 were fairly satisfied, and 16 were not satisfied. Body contouring added about 6 % to the costs of surgical treatment for morbid obesity. CONCLUSIONS: Fewer patients than in other studies expressed a desire for post-bariatric surgery, 15 % actually proceeded to this step. The low demand was neither due to denied coverage nor to unfavourable results of plastic surgery. Additional costs for body contouring were less than expected.

Effects of gastric bypass surgery on insulin resistance and insulin secretion in nondiabetic obese patients.

Roux-en-Y-Gastric-Bypass (RYGB) reduces overall and diabetes-specific mortality by 40% and over 90%. This study aims to gain insight into the underlying mechanisms of this effect. We evaluated time-courses of glucose, insulin, C-peptide, and the incretin glucagon like peptide-1 (GLP-1) following an oral glucose load. Insulin-sensitivity was measured by a hyperinsulinemic-isoglycemic-clamp-test; glucose-turnover was determined using D-[6,6-(2)H(2)] glucose. Examinations were performed in six nondiabetic patients with excess weight before (PRE: BMI: 49.3 ± 3.2 kg/m(2)) and 7 months after RYGB (POST: BMI: 36.7 ± 2.9 kg/m(2)), in a lean (CON: BMI: 22.6 ± 0.6 kg/m(2)) and an obese control group (CONob) without history of gastrointestinal surgery (BMI: 34.7 ± 1.2 kg/m(2)). RYGB reduced fasting plasma concentrations of insulin and C-peptide (P < 0.01, respectively) whereas fasting glucose concentrations remained unchanged. After RYGB increase of C-peptide concentration following glucose ingestion was significantly higher compared to all other groups (dynamic-area under the curve (Dyn-AUC): 0-90 min: POST: 984 ± 115 ng·min/ml, PRE: 590 ± 67 ng·min/ml, CONob: 440 ± 44 ng·min/ml, CON: 279 ± 22 ng·min/ml, P < 0.01 respectively). Early postprandial increase of glucose concentration was however not affected. GLP-1 concentrations following glucose ingestion were sixfold higher after RYBG than before (P = 0.01). Insulin-stimulated glucose uptake tended to increase postoperatively (M-value: PRE: 1.8 ± 0.5, POST: 3.0 ± 0.3, not significant (n.s.)). Endogenous glucose production (EGP) was unaffected by RYGB. Hepatic insulin resistance index improved after RYGB and was then comparable to both control groups (PRE: 29.2 ± 4.3, POST: 12.6 ± 1.1, P < 0.01). RYGB results in hyper-secretion of insulin and C-peptide, whereas improvements of insulin resistance are minor and seem to occur rather in the liver and the adipose tissue than in the skeletal muscle.

Conversion from sleeve gastrectomy to Roux-en-Y gastric bypass--indications and outcome.

BACKGROUND: Due to excellent weight loss success in the short-time follow-up, sleeve gastrectomy (SG) has gained popularity as sole and definitive bariatric procedure. In the long-term follow-up, weight loss failure and intractable severe reflux can necessitate further surgical intervention. METHODS: A retrospective analysis of laparoscopic conversions from SG to Roux-en-Y gastric bypass (RYGB) was performed to assess the efficacy for reflux relief and weight loss success. RESULTS: A total of eight out of 73 patients (11%) underwent conversion to RYGB for severe reflux (n=3) or weight regain (n=5) after a median interval of 33 months following laparoscopic sleeve gastrectomy. In one of the patients, a banded gastric bypass was performed. In both groups, conversion to RYGB was successful, as proton pump inhibitor medication could be discontinued in all patients presenting with severe reflux, and a significant weight loss could be achieved in the patients with weight regain within a median follow-up of 33 months. Postoperative complications were observed in only one patient as leakage at the gastrojejunostomy was successfully treated by temporary stent placement. CONCLUSION: Conversion to RYGB is an effective treatment for weight regain or intractable reflux symptoms following SG. Thus, SG can be performed, intended as sole and definitive bariatric intervention, with conversion from SG to RYGB as an exit strategy for these complications.

Sleeve gastrectomy as sole and definitive bariatric procedure: 5-year results for weight loss and ghrelin.

BACKGROUND: Due to excellent efficacy for weight loss in the short-term follow-up, sleeve gastrectomy (SG) has gained enormous popularity as bariatric procedure, not only as first step in high-risk or super-obese patients but mainly as a sole and definitive operation in morbidly obese. In contrast to a large number of short and intermediate-term results, no series of SG with a follow-up of 5 years or more has been published so far. METHODS: We report on the weight loss results of our first consecutive 26 patients with a complete follow-up of 5 years. Furthermore in a subgroup of 12 patients, plasma ghrelin levels were measured preoperatively, and up to 5 years following SG. RESULTS: Weight loss defined as mean percent excess weight loss (%EWL) was found as 57.5 +/- 4.5, 60.3 +/- 5.0, 60.0 +/- 5.7, 58.4 +/- 5.4, and 55.0 +/- 6.8 (not converted, n = 21) for the first 5 years. Weight regain of more than 10 kg from nadir was observed in five (19.2%) of the 26 patients. Four of the patients (15.4%) were converted to gastric bypass due to severe reflux (n = 1, 3.8%) and weight loss failure (n = 3, 11.5%). A total of eight patients (30.8%) were at chronic need for proton pump inhibitor medication due to severe reflux. Plasma ghrelin levels were reduced from 593 +/- 52 to 219 +/- 23 pg/ml 12 months postoperatively, with a slightly, non-significant increase toward the 5-years values of mean 257 +/- 23 pg/ml. CONCLUSIONS: At 5-year follow-up, a mean EWL of 55.0 +/- 6.8% was achieved, indicating that SG leads to stable weight loss. Beside significant weight regain, severe reflux might necessitate conversion to gastric bypass or duodenal switch. After an immediate reduction postoperatively, plasma ghrelin levels remained low for the first 5 years postoperatively.

Circular- vs. linear-stapled gastrojejunostomy in laparoscopic Roux-en-Y gastric bypass.

BACKGROUND: Different surgical techniques have been developed for the gastrojejunostomy (GJS) in laparoscopic Roux-en-Y gastric bypass (LRYGBP) with the anastomosis performed in a circular-stapled, linear-stapled, or totally hand-sewn way. No technique seems superior to the other as no consistent data on weight loss or complication rates were described. METHODS: A matched-pair study was conducted including a total of 150 patients, who underwent primary antegastric, antecolic LRYGBP between August 2003 and February 2007. Early weight loss and the incidence of GJS strictures or leaks and wound infections were compared between circular-stapled anastomosis (CSA) and linear-stapled anastomosis (LSA). Both groups were matched for age, sex, and body mass index. RESULTS: Excess weight loss at 3 months was slightly better with the CSA (p = 0.002) and comparable thereafter. Percentage of excess weight loss at 6, 12, and 24 months was 55.9 +/- 17.5% vs. 51.2 +/- 14.5%, 69.5 +/- 20.9% vs. 71.4 +/- 22.6%, and 70.8 +/- 22.4% vs. 73.2 +/- 23.4%, respectively (CSA vs. LSA). Strictures at the GJS were found only in the CSA group (n = 4), and leaks were found in one patient of the CSA group. More wound infections were observed in patients of the CSA group (ten vs. one). CONCLUSIONS: CSA and LSA lead to comparable early weight loss in LRYGB. Thus, the technique is the surgeon's choice. In CSA, a higher incidence of GJS strictures and wound infections was observed. As weight regain following LRYGBP is commonly observed after at least 3 years, a longer follow-up is needed to compare the incidence of weight regain in circular- vs. linear-stapled GJS.