Diminished counterregulatory responses to meal-induced hypoglycemia 4 years after RYGB

PURPOSE: Post-bariatric hypoglycemia is a complication of bariatric surgery, especially Roux-en-Y gastric bypass (RYGB). The counterregulatory hormonal and sympathetic neural responses were measured during a previously reported meal test in which 48% had an almost asymptomatic hypoglycemic event. MATERIALS AND METHODS: Forty-four randomly selected patients 4 years after RYGB. A liquid meal test (MMT) after overnight fasting. Based on the glucose nadir during the MMT, patients were divided in a hypo group (glucose < 3.3 mmol/L) and a non-hypo group (glucose ≥ 3.3 mmol/L). Cortisol, epinephrine, norepinephrine, blood pressure, and heart rate were measured up to 180 min after ingestion of the meal. Incremental areas under the curve (iAUC), peak, and delta hormone responses after the glucose nadir were calculated. Parameters were compared between the hypo and non-hypo groups. RESULTS: A total of 21/44 (48%) had an almost asymptomatic hypoglycemic event. Cortisol and epinephrine responses in the hypo group were not increased compared to the non-hypo group, and there were no signs of increased sympathetic nerve activity. Peak and delta cortisol were lower in the hypo compared to the non-hypo group. Norepinephrine was higher in the hypo group especially in the time frame 60-120 and 120-180 min after start of the meal. CONCLUSION: No increase in epinephrine and a lower cortisol response to hypoglycemia were observed compared to normoglycemia during a meal test in patients after RYGB. Norepinephrine levels were higher in the hypo group. These findings may suggest that possible recurrent hypoglycemia after RYGB results in blunting of counterregulatory responses indicative of hypoglycemia-induced autonomic failure. CLIN TRIAL REGISTER ID: ISRCTN 11738149

Altered bile acid kinetics contribute to postprandial hypoglycaemia after Roux-en-Y gastric bypass surgery

Background/objectives: Bile acids (BA) act as detergents in intestinal fat absorption and as modulators of metabolic processes via activation of receptors such as FXR and TGR5. Elevated plasma BA as well as increased intestinal BA signalling to promote GLP-1 release have been implicated in beneficial health effects of Roux-en-Y gastric bypass surgery (RYGB). Whether BA also contribute to the postprandial hypoglycaemia that is frequently observed post-RYGB is unknown. Methods: Plasma BA, fibroblast growth factor 19 (FGF19), 7α-hydroxy-4-cholesten-3-one (C4), GLP-1, insulin and glucose levels were determined during 3.5 h mixed-meal tolerance tests (MMTT) in subjects after RYGB, either with (RYGB, n = 11) or without a functioning gallbladder due to cholecystectomy (RYGB-CC, n = 11). Basal values were compared to those of age, BMI and sex-matched obese controls without RYGB (n = 22). Results: Fasting BA as well as FGF19 levels were elevated in RYGB and RYGB-CC subjects compared to non-bariatric controls, without significant differences between RYGB and RYGB-CC. Postprandial hypoglycaemia was observed in 8/11 RYGB-CC and only in 3/11 RYGB. Subjects who developed hypoglycaemia showed higher postprandial BA levels coinciding with augmented GLP-1 and insulin responses during the MMTT. The nadir of plasma glucose concentrations after meals showed a negative relationship with postprandial BA peaks. Plasma C4 was lower during MMTT in subjects experiencing hypoglycaemia, indicating lower hepatic BA synthesis. Computer simulations revealed that altered intestinal transit underlies the occurrence of exaggerated postprandial BA responses in hypoglycaemic subjects. Conclusion: Altered BA kinetics upon ingestion of a meal, as frequently observed in RYGB-CC subjects, appear to contribute to postprandial hypoglycaemia by stimulating intestinal GLP-1 release

Nutritional opportunities and challenges after bariatric surgery

Obesity is a serious health problem and currently bariatric surgery (weight loss surgery such as gastric bypass surgery) is the most effective long-term treatment. The general aim of the thesis is contribute to the optimization of the care after bariatric surgery and consists of two parts. In part I. Nutritional opportunities it is investigated how nutrition, in particular dietary protein and its building blocks the amino acids, could be useful to optimize the results of gastric bypass surgery. Among other things, the influence of amino acids in blood on the feeling of hunger/satiety and associated hormones is studied. Additionally, a meal test with two different proteins, varying in amino acid composition, is used to compare the effect of these proteins on hunger, satiety and associated hormones. Part II. Nutritional challenges investigates the occurrence and cause/contributing factors of postbariatric hypoglycemia, a complication after bariatric surgery in which patients have too low glucose concentrations 1-2 hours after a meal. In popular terms this is referred to as ‘hypo’, which in severe cases could lead to fainting or coma. These studies use a meal test, after which the blood glucose concentration and various hormones/bile acids are determined. It is also explored whether the test subjects have symptoms of this postbariatric hypoglycemia and whether the body can respond adequately to this with a stress response. An extra focus is placed on subjects with a cholecystectomy (gallbladder removal), to evaluate the influence this procedure on the ‘hypo’

De invloed van perineale bacteriële resistentie voor ciprofloxacine op de incidentie van infecties na transrectale echogeleide prostaatbiopsie onder profylactisch ciprofloxacine

Introduction: Transrectal ultrasound guided prostate biopsy (TRUSPB) is an essential procedure in the diagnosis of prostate cancer. Unfortunately, this procedure has risks, including infection. For this reason, a prophylaxis is recommended, such as ciprofloxacin. However, there is an increasing trend regarding ciprofloxacin resistance of E. coli. Recent literature suggests that this resistance is the most likely cause of infection after TRUSPB. The aim of this study is to demonstrate whether the occurrence of an infection after TRUSPB under prophylactic ciprofloxacin is due to the bacterial resistance to this antibiotic and that this resistance can be demonstrated by a perineum swab. Material and Method: From 1 October 2012 to 31 December 2012 all men in Ziekenhuisgroep Twente en Medisch Spectrum Twente, who underwent prostate biopsy and granted informed consent, were included. Exclusion criteria were immunological diseases and status after radical prostatectomy. A perineum swab was obtained prior to TRUSPB with ciprofloxacin as prophylaxis. This culture was assessed on gram-negative bacteria (GNB) and ciprofloxacin resistance. If a culture showed no GNB, ciprofloxacin resistance could not be tested and therefore these cultures could not be included to answer the research question. At least 31 days after the TRUSPB and the perineum swab, the electronic medical records of the enrolled patients were evaluated to inventory subjective and objective infectious symptoms. Hereafter, comparison was done on the incidence of infection between patients with ciprofloxacin-resistant GNB on the perineum and the patients without ciprofloxacin resistant GNB on the perineum. Results: Of the 144 executed swabs, 25 (17.4%) had control cultures positive for GNB. Only these 25 cases were included for the research question. In previous calculations of the sample size this failure was not calculated. Of the 25 patients enrolled, five (20%) ciprofloxacin-resistant gram-negative rods. In total, there were two infectious complications in the 25 patients. In both groups, there was one case. Both groups had a casus of prostatitis, which was not confirmed by the urologist. There was no significant difference between the two groups and the occurrence of infection (p = 0.367). In addition, the age found in the group without ciprofloxacin-resistant bacteria was average 68.5 years, in contrast to the group with ciprofloxacin-resistant bacteria with a mean age of 59.4 years (p = 0.024). Univariate logistic regression showed an odds ratio of 0.818 age in the presence of ciprofloxacin resistant GNB on the perineum (p = 0.036). Conclusion: It could not be proven that bacterial resistance to ciprofloxacin at the perineum had any influence on the development of infections after TRUSPB. Also a perineum swab showed to be no good measure instrument in this study. Prospective multicenter study with a larger sample size and another measure instrument is advised.

Prevalence and pathophysiology of early dumping in patients after primary Roux-en-Y gastric bypass during a mixed-meal tolerance test

BACKGROUND: Early dumping is a poorly defined and incompletely understood complication after Roux-en-Y gastric (RYGB). OBJECTIVE: We performed a mixed-meal tolerance test in patients after RYGB to address the prevalence of early dumping and to gain further insight into its pathophysiology. SETTING: The study was conducted in a regional hospital in the northern part of the Netherlands. METHODS: From a random sample of patients who underwent primary RYGB between 2008 and 2011, 46 patients completed the mixed-meal tolerance test. The dumping severity score for early dumping was assessed every 30 minutes. A sum score at 30 or 60 minutes of ≥5 and an incremental score of ≥3 points were defined as indicating a high suspicion of early dumping. Blood samples were collected at baseline, every 10 minutes during the first half hour, and at 60 minutes after the start. RESULTS: The prevalence of a high suspicion of early dumping was 26%. No differences were seen for absolute hematocrit value, inactive glucagon-like peptide-1, and vasoactive intestinal peptide between patients with or without early dumping. Patients at high suspicion of early dumping had higher levels of active glucagon-like peptide-1 and peptide YY. CONCLUSION: The prevalence of complaints at high suspicion of early dumping in a random population of patients after RYGB is 26% in response to a mixed-meal tolerance test. Postprandial increases in both glucagon-like peptide-1 and peptide YY are associated with symptoms of early dumping, suggesting gut L-cell overactivity in this syndrome

Cholecystectomy increases the risk of dumping syndrome and postbariatric hypoglycemia after bariatric surgery

Background: Dumping syndrome (DS) and postbariatric hypoglycemia (PBH) are frequent complications of bariatric surgery. Bile acids (BA) have been implicated in their pathogenesis because both bariatric surgery and cholecystectomy (CCx) are known to modulate human BA metabolism. Objectives: Our investigation aimed to compare the prevalence of self-reported complaints of DS and PBH in postbariatric patients with and without CCx. Setting: A large peripheral hospital in the Netherlands. Methods: All patients who underwent bariatric surgery in 2008-2011 received standardized questionnaires on DS/PBH complaints. The relative risk (RR) of CCx was calculated as the risk of perceived DS and PBH in patients with and without CCx. Results: Of 590 participants, 146 (25%) had CCx before assessment of DS/PBH complaints. Participants were mostly female (82%) with median age of 46 years (interquartile range, 39-53). The RR for DS after CCx was higher in patients with body mass index = 70% (RR, 2.73; 95% CI, 1.57-4.77; P = .0004) with greater risk of DS. The RR for PBH was higher after CCx in sleeve gastrectomy patients (RR, 4.5; 95% CI, 1.00-20.3; P = .036). Conclusion: High suspicion of DS and PBH after CCx is increased after bariatric surgery in certain subgroups, suggesting involvement of altered BA metabolism in their pathophysiology. (C) 2020 American Society for Bariatric Surgery. Published by Elsevier Inc

Waterbird seed-dispersal networks are similarly nested but less modular than those of frugivorous birds, and not driven by functional traits

Frugivory is widely recognized as vital for the dispersal of many plants. Moreover, plant species and their frugivorous dispersers form seed‐dispersal assemblages whose structure has important implications for the persistence and stability of the community. However, dispersal interactions between plants and non‐frugivorous animal groups such as waterbirds remain largely understudied. We aimed to characterize the structure of waterbird seed‐dispersal networks, assess if this structure is similar to that of networks formed between frugivorous birds and fleshy‐fruited plants, and identify bird or plant functional traits important for the maintenance of network structure. We used network analyses and data from four community‐level studies on waterbird gut contents, including 12 bird and 88 plant species. We compared the network structure of waterbirds to those from previous studies of frugivorous birds. We also related the contribution of each species to the network structure with functional traits (e.g. size, habitat requirements, diet). Waterbird seed‐dispersal networks are similarly nested (i.e. specialists interact with a subset of those species that interact with generalists) but less modular (i.e. fewer semi‐independent groups of highly interacting species) than those of frugivores. Dabbling ducks, diving ducks and rallids did not separate into modules. The contribution of bird or plant species to network structure was not related to any functional trait. Seed‐dispersal networks of waterbirds share some organizational patterns with those of frugivores, but the underlying processes are not related to functional traits. This is probably related to fundamental differences between waterbirds and frugivores in how seeds are ingested. Differences in the functional role of waterbirds for seed dispersal are likely driven by other processes such as differences in population size, movement, ecology or gut processing of seeds.Peer reviewe

Waterbird seed‐dispersal networks are similarly nested but less modular than those of frugivorous birds, and not driven by functional traits

Frugivory is widely recognized as vital for the dispersal of many plants. Moreover, plant species and their frugivorous dispersers form seed‐dispersal assemblages whose structure has important implications for the persistence and stability of the community. However, dispersal interactions between plants and non‐frugivorous animal groups such as waterbirds remain largely understudied. We aimed to characterize the structure of waterbird seed‐dispersal networks, assess if this structure is similar to that of networks formed between frugivorous birds and fleshy‐fruited plants, and identify bird or plant functional traits important for the maintenance of network structure. We used network analyses and data from four community‐level studies on waterbird gut contents, including 12 bird and 88 plant species. We compared the network structure of waterbirds to those from previous studies of frugivorous birds. We also related the contribution of each species to the network structure with functional traits (e.g. size, habitat requirements, diet). Waterbird seed‐dispersal networks are similarly nested (i.e. specialists interact with a subset of those species that interact with generalists) but less modular (i.e. fewer semi‐independent groups of highly interacting species) than those of frugivores. Dabbling ducks, diving ducks and rallids did not separate into modules. The contribution of bird or plant species to network structure was not related to any functional trait. Seed‐dispersal networks of waterbirds share some organizational patterns with those of frugivores, but the underlying processes are not related to functional traits. This is probably related to fundamental differences between waterbirds and frugivores in how seeds are ingested. Differences in the functional role of waterbirds for seed dispersal are likely driven by other processes such as differences in population size, movement, ecology or gut processing of seeds