Copeptin, a surrogate marker for arginine vasopressin secretion, is positively associated with glucagon.

AIM: To explore the association of plasma copeptin, the C-terminal portion of provasopressin and a stable surrogate marker for arginine vasopressin secretion, with plasma glucagon in obese men and men of normal weight. METHODS: We measured fasting blood concentrations of copeptin and glucagon in 102 healthy obese men (mean ± sd age 49.4 ± 10.2 years) and a control group 27 healthy men of normal weight (mean ± sd age 51.5 ± 8.4 years). Differences between groups were evaluated using t-tests, and multiple linear regression analysis, adjusting for age and weight status (normal weight vs obese), was used to calculate unstandardized regression coefficients (ß) with 95% CIs between copeptin and glucagon. Copeptin was (natural) log-transformed. RESULTS: The obese men had higher [median (interquartile range)] plasma copeptin concentrations [6.6 (4.6-9.5) vs 4.9 (3.5-6.8) pmol/l; P = 0.040] and higher mean ± sd plasma glucagon concentrations (8.5 ± 3.8 vs 5.3 ± 1.4 pmol/l; P < 0.001) than the normal-weight men. Adjusted for age and weight status, copeptin was significantly associated with glucagon (ß = 1.35, 95% CI 0.13-2.57; P = 0.031). No significant interaction effect between copeptin and weight status on glucagon was found (P = 0.81). CONCLUSIONS: Obese men had higher concentrations of copeptin and glucagon than men of normal weight. Copeptin was positively associated with glucagon. Our data suggest that increased arginine vasopressin-stimulated glucagon secretion might contribute to higher glucagon concentrations; therefore, increased arginine vasopressin secretion, in addition to other factors, could further aggravate the hyperglucagonaemic state found in obese individuals.

Impact of weight loss achieved through a multidisciplinary intervention on appetite in patients with severe obesity.

The impact of lifestyle-induced weight loss (WL) on appetite in patients with obesity remains controversial. This study aimed to assess the short- and long-term impact of WL achieved by diet and exercise on appetite in patients with obesity. Thirty-five (22 females) adults with severe obesity (body mass index: 42.5 ± 5.0 kg/m2) underwent a 2-yr WL program focusing on diet and exercise. Body weight (BW), cardiovascular fitness (V̇o2max), appetite feelings, and plasma concentrations of insulin, active ghrelin (AG), glucagon-like peptide 1 (GLP-1), peptide YY (PYY), and cholecystokinin (CCK), in the fasting and postprandial states, were measured at baseline (B), week 4 (W4), and 1 and 2 yr (and average values for all fasting and postprandial time points computed). BW was significantly reduced and V̇o2max (ml·kg-1·min-1) increased at all time points compared with B (3.5, 8.1, and 8.4% WL and 7, 11, and 8% increase at W4 and 1 and 2 yr, respectively). Basal hunger and average hunger and desire to eat were significantly increased at 1 and 2 yr. Basal fullness was significantly increased at W4, and average ratings were reduced at 1 yr. Average AG and PYY were significantly increased, and insulin was reduced, at all time points compared with B. Average GLP-1 was reduced at W4, and CCK was increased at 2 yr. After lifestyle-induced WL, patients with severe obesity will, therefore, have to deal with increased hunger in the long term. In conclusion, sustained WL at 2 yr achieved with diet and exercise is associated with increased hunger feelings and ghrelin concentration but also increased postprandial concentrations of satiety hormones.

Morning and afternoon appetite and gut hormone responses to meal and stress challenges in obese individuals with and without binge eating disorder.

BACKGROUND: Eating late in the day is common, and stress can induce eating. Little is understood about how time of day and stress interact to affect appetite and thereby body weight. These may be particularly important influences in binge eaters, who tend to binge in the evening, and in response to stress. METHOD: Obese participants with (n=16) and without (n=16) binge eating disorder (BED) participated in two identical test protocols beginning either in the morning or the afternoon (AM condition/PM condition), each following an 8 h fast. For each protocol, they first received a standardized liquid meal (0900/1600 hours), then a stress test (Socially Evaluated Cold Pressor Test, 1110/1810 hours), and then a multi-item ad libitum buffet meal (1140/1840 hours) while rating appetite and stress and having blood drawn for hormone measures. RESULTS: Appetite at baseline was greater in the PM than in the AM condition (higher hunger, lower fullness). Following the liquid meal, area under the curve (AUC) values for hunger and ghrelin were greater and AUC values for peptide YY lower in the PM than in the AM condition. Only those with BED showed lower fullness AUC in the PM condition, as well as a pattern of higher initial PM and lower initial AM ghrelin. Following the stress test, cortisol and ghrelin increased in both the AM and PM conditions, but higher ghrelin AUC and lower cortisol AUC were observed in the PM condition. Again, only participants with BED showed lower fullness AUC in the PM condition. Buffet meal intake was similar across groups and conditions but those with BED reported greater loss of control and binge resemblance than those without. CONCLUSIONS: Afternoon/evening may be a high-risk period for overeating, particularly when paired with stress exposure, and for those with binge eating.

Adaptive changes in pancreas post Roux-en-Y gastric bypass induced weight loss.

BACKGROUND: Obesity has been shown to trigger adaptive increases in pancreas parenchymal and fat volume. Consecutively, pancreatic steatosis may lead to beta-cell dysfunction. However, it is not known whether the pancreatic tissue components decrease with weight loss and pancreatic steatosis is reversible following Roux-en-Y gastric bypass (RYGB). Therefore, the objective of the study was to investigate the effects of RYGB-induced weight loss on pancreatic volume and glucose homeostasis. METHODS: Eleven patients were recruited in the Obesity Centre of the University Medical Centre Hamburg-Eppendorf. Before and 6 months after RYGB, total GLP-1 levels were measured during oral glucose tolerance test. To assess changes in visceral adipose tissue and pancreatic volume, MRI was performed. Measures of glucose homeostasis and insulin indices were assessed. Fractional beta-cell area was estimated by correlation with the C-peptide-to-glucose ratio; beta-cell mass was calculated by the product of beta-cell area and pancreas parenchymal weight. RESULTS: Pancreas volume decreased from 83.8 (75.7-92.0) to 70.5 (58.8-82.3) cm3 (mean [95% CI], P = .001). The decrease in total volume was associated with a significant decrease in fat volume. Fasting insulin and C-peptide were lower post RYGB. HOMA-IR levels decreased, whereas insulin sensitivity increased (P = .03). This was consistent with a reduction in the estimated beta-cell area and mass. CONCLUSIONS: Following RYGB, pancreatic volume and steatosis adaptively decreased to "normal" levels with accompanying improvement in glucose homeostasis. Moreover, obesity-driven beta-cell expansion seems to be reversible; however, future studies must define a method to more accurately estimate functional beta-cell mass to increase our understanding of glucose homeostasis after RYGB.

Increased glucose-stimulated FGF21 response to oral glucose in obese nondiabetic subjects after Roux-en-Y gastric bypass.

OBJECTIVE: The positive metabolic outcome of Roux-en-Y gastric bypass (RYGB) surgery may involve fibroblast growth factor 21 (FGF21), in both the fasting state and postprandially. We measured the fasting levels of FGF21 before and after bariatric surgery as well as the postprandial FGF21 responses after a glucose load and after a mixed meal. DESIGN: Observational intervention trial. PATIENTS AND MEASUREMENTS: Eight obese, nondiabetic patients underwent RYGB. Plasma FGF21 was measured both before and after surgery on three different days during oral glucose loads (25 g or 50 g glucose) or a mixed meal. Blood samples were taken right before the meal and at 15-min intervals until 90 min and at 150 min and 210 min relative to the start of the meal. RESULTS: Overall, fasting plasma FGF21 did not change significantly before and after surgery (262 ± 71 vs 411 ± 119 pg/ml), but for three subjects, fasting plasma FGF21 increased significantly after surgery. Furthermore, FGF21 levels increased significantly at t = 90 and t = 150 min in response to 50 g glucose, but not after a mixed meal. CONCLUSIONS: In conclusion, the observed increase in postprandial plasma FGF21 in response to glucose and the lack of FGF21 response to a mixed meal may have important implications for the physiologic role of FGF21. The increase in postprandial FGF21 in response to glucose in the early postoperative period may contribute to the metabolic improvements observed after gastric bypass.

Nutrient re-routing and altered gut-islet cell crosstalk may explain early relief of severe postprandial hypoglycaemia after reversal of Roux-en-Y gastric bypass.

BACKGROUND: Roux-en-Y gastric bypass is associated with an increased risk of postprandial hyperinsulinaemic hypoglycaemia, but the underlying pathophysiology remains poorly understood. We therefore examined the effect of re-routing of nutrient delivery on gut-islet cell crosstalk in a person with severe postprandial hypoglycaemia after Roux-en-Y gastric bypass. CASE REPORT: A person with severe postprandial hypoglycaemia, who underwent surgical reversal of Roux-en-Y gastric bypass, was studied before reversal and at 2 weeks and 3 months after reversal surgery using liquid mixed meal tests and hyperinsulinaemic-euglycaemic clamps. The nadir of postprandial plasma glucose rose from 2.8 mmol/l to 4.1 mmol/l at 2 weeks and to 4.4 mmol/l at 3 months after reversal. Concomitant insulin- and glucagon-like peptide-1 secretion (peak concentrations and area under the curve) clearly decreased after reversal, while concentrations of glucose-dependent insulinotropic polypeptide and ghrelin increased. Insulin clearance declined after reversal, whereas clamp-estimated peripheral insulin sensitivity was unchanged. The person remained without symptoms of hypoglycaemia, but had experienced significant weight gain at 15-month follow-up. DISCUSSION: Accelerated nutrient absorption may be a driving force behind postprandial hyperinsulinaemic hypoglycaemia after Roux-en-Y gastric bypass. Re-routing of nutrients by reversal of the Roux-en-Y gastric bypass diminished postprandial plasma glucose excursions, alleviated postprandial insulin and glucagon-like peptide-1 hypersecretion and eliminated postprandial hypoglycaemia, which emphasizes the importance of altered gut-islet cell crosstalk for glucose metabolism after Roux-en-Y gastric bypass.

Near-normalization of glycaemic control with glucagon-like peptide-1 receptor agonist treatment combined with exercise in patients with type 2 diabetes.

AIMS: To investigate the effects of exercise in combination with a glucagon-like peptide-1 receptor agonist (GLP-1RA), liraglutide, or placebo for the treatment of type 2 diabetes. METHODS: Thirty-three overweight, dysregulated and sedentary patients with type 2 diabetes were randomly allocated to 16 weeks of either exercise and liraglutide or exercise and placebo. Both groups had three supervised 60-minute training sessions per week including spinning and resistance training. RESULTS: Glycated haemoglobin (HbA1c) levels dropped by a mean ± standard deviation of 2.0% ± 1.2% (from 8.2% ± 1.4%) in the exercise plus liraglutide group vs 0.3% ± 0.9% (from 8.0% ± 1.2%) in the exercise plus placebo group ( P < .001), and body weight was reduced more with liraglutide (-3.4 ± 2.9 kg vs -1.6 ± 2.3 kg; P < .001). Compared with baseline, similar reductions were seen in body fat (exercise plus liraglutide: -2.5% ± 1.4% [ P < .001]; exercise plus placebo: -2.2% ± 1.9% [ P < .001]) and similar increases were observed in maximum oxygen uptake (exercise plus liraglutide: 0.5 ± 0.5 L O2 /min [ P < .001]; exercise plus placebo: 0.4 ± 0.4 L O2 /min [ P = .002]). Greater reductions in fasting plasma glucose (-3.4 ± 2.3 mM vs -0.3 ± 2.6 mM, P < .001) and systolic blood pressure (-5.4 ± 7.4 mm Hg vs -0.6 ± 11.1 mm Hg, P < .01) were seen with exercise plus liraglutide vs exercise plus placebo. The two groups experienced similar increases in quality of life during the intervention. CONCLUSIONS: In obese patients with type 2 diabetes, exercise combined with GLP-1RA treatment near-normalized HbA1c levels and caused a robust weight loss when compared with placebo. These results suggest that a combination of exercise and GLP-1RA treatment is effective in type 2 diabetes.

The Long-term Durability of Intra-operatively Placed Palmaz Stents for the Treatment of Type Ia Endoleaks After EVAR of Abdominal Aortic Aneurysm.

OBJECTIVE/BACKGROUND: The objective was to analyze the long-term durability of intra-operatively placed Palmaz stents for type Ia endoleaks, and the evolution of aneurysm neck morphology. METHODS: This was a retrospective cohort study conducted at a tertiary referral centre. Patients treated between 1998 and 2012 were reviewed with regard to pre-, intra-, and post-operative data. Crude and relative survival estimates were calculated, with the latter referring only to patients with ≥ 3 months' follow-up. RESULTS: In total, 125 patients were included (83 elective, 22 ruptures, 20 symptomatic). Nine patients died perioperatively (two elective, seven acute). Median follow-up was 43 months (range 15-72). Seven patients had late abdominal aortic aneurysm related deaths. There were 51 re-interventions (seven type Ia endoleak related). Five year crude primary, primary assisted, and secondary success rates were 55 ± 5%, 66 ± 5%, and 70 ± 5%, respectively. These crude rates were superior for elective patients (p = .008, p = .031, and p = .037, respectively), but the relative rates were not (p = .187, p = .640, p = .558, respectively). Primary and assisted freedom from type Ia endoleak 5 years post-operatively were 84 ± 4% and 89 ± 3%, respectively. These rates were superior in elective patients (p = .066 and p = .145, respectively), especially when relative rates were analysed (p = .025 and p = .063, respectively). The visceral aortic diameter increased significantly between the first and the last post-operative imaging in 15/91 (16%), 12/91 (13%), 34/91 (37%), and 30/91 (33%) patients at the levels of coeliac trunk, superior mesenteric artery, lowest renal artery, and 9 mm distal to lowest renal artery, respectively. CONCLUSION: Intra-operatively placed Palmaz stents confer high long-term freedom from type Ia endoleak. Palmaz stents are an acceptable intra-operative bailout tool in the acute setting, but should not be used to extend elective infrarenal endovascular aneurysm repair to more demanding anatomies.

Impaired beta cell sensitivity to incretins in type 2 diabetes is insufficiently compensated by higher incretin response.

BACKGROUND AND AIMS: The incretin effect is impaired in type 2 diabetes (T2D), but the underlying mechanisms are only partially understood. We investigated the relationships between the time course of the incretin effect and that of glucose-dependent insulinotropic polypeptide (GIP) and glucagon-like peptide-1 (GLP-1) during oral glucose tolerance tests (OGTTs), thereby estimating incretin sensitivity of the beta cell, and its associated factors. METHODS AND RESULTS: Eight patients with T2D and eight matched subjects with normal glucose tolerance (NGT) received 25, 75, and 125 g OGTTs and corresponding isoglycemic glucose infusions (IIGI). The time course of the incretin effect, representing potentiation of insulin secretion by incretins (PINCR), was determined by mathematical modelling as the time-dependent fold increase in insulin secretion during OGTT compared to IIGI. The time course of PINCR was correlated with that of both GIP and GLP-1 in each subject (median r = 0.67 in NGT and 0.45 in T2D). We calculated an individual beta cell sensitivity to incretins (SINCR) using a weighted average of GIP and GLP-1 (pooled incretin concentration, PIC), as the slope of the relationship between PINCR and PIC. SINCR was reduced in T2D (p < 0.01). In the whole group, mean PIC, GIP and GLP-1 concentrations during the OGTT were inversely correlated with SINCR, but T2D had lower PIC, GIP and GLP-1 levels at the same SINCR (p < 0.05). CONCLUSION: Relative incretin insensitivity is partly compensated for by higher incretin secretory responses. However, T2D shows both impairment in incretin sensitivity and abnormal compensation by incretin secretion.

Fructose intervention for 12 weeks does not impair glycemic control or incretin hormone responses during oral glucose or mixed meal tests in obese men.

BACKGROUND AND AIMS: Incretin hormones glucagon-like peptide (GLP)-1 and glucose-dependent insulinotropic polypeptide (GIP) are affected early on in the pathogenesis of metabolic syndrome and type 2 diabetes. Epidemiologic studies consistently link high fructose consumption to insulin resistance but whether fructose consumption impairs the incretin response remains unknown. METHODS AND RESULTS: As many as 66 obese (BMI 26-40 kg/m2) male subjects consumed fructose-sweetened beverages containing 75 g fructose/day for 12 weeks while continuing their usual lifestyle. Glucose, insulin, GLP-1 and GIP were measured during oral glucose tolerance test (OGTT) and triglycerides (TG), GLP-1, GIP and PYY during a mixed meal test before and after fructose intervention. Fructose intervention did not worsen glucose and insulin responses during OGTT, and GLP-1 and GIP responses during OGTT and fat-rich meal were unchanged. Postprandial TG response increased significantly, p = 0.004, and we observed small but significant increases in weight and liver fat content, but not in visceral or subcutaneous fat depots. However, even the subgroups who gained weight or liver fat during fructose intervention did not worsen their glucose, insulin, GLP-1 or PYY responses. A minor increase in GIP response during OGTT occurred in subjects who gained liver fat (p = 0.049). CONCLUSION: In obese males with features of metabolic syndrome, 12 weeks fructose intervention 75 g/day did not change glucose, insulin, GLP-1 or GIP responses during OGTT or GLP-1, GIP or PYY responses during a mixed meal. Therefore, fructose intake, even accompanied with mild weight gain, increases in liver fat and worsening of postprandial TG profile, does not impair glucose tolerance or gut incretin response to oral glucose or mixed meal challenge.

Short communication: Promotion of glucagon-like peptide-2 secretion in dairy calves with a bioactive extract from Olea europaea.

Diarrhea episodes in dairy calves involve profound alterations in the mechanism controlling gut barrier function that ultimately compromise intestinal permeability to macromolecules, including pathogenic bacteria. Intestinal dysfunction models suggest that a key element of intestinal adaptation during the neonatal phase is the nutrient-induced secretion of glucagon-like peptide (GLP)-2 and associated effects on mucosal cell proliferation, barrier function, and inflammatory response. Bioactive molecules found in Olea europaea have been shown to induce the release of regulatory peptides from model enteroendocrine cells. The ability to enhance GLP-2 secretion via the feeding of putative GLP-2 secretagogues is untested in newborn calves. The objectives of this study were to determine whether feeding a bioactive extract from Olea europaea (OBE) mixed in the milk replacer (1) can stimulate GLP-2 secretion beyond the response elicited by enteral nutrients and, thereby, (2) improve intestinal permeability and animal growth as well as (3) reduce the incidence of diarrhea in preweaning dairy calves. Holstein heifer calves (n = 60) were purchased, transported to the research facility, and blocked by body weight and total serum protein and assigned to 1 of 3 treatments. Treatments were control (CON), standard milk replacer (MR) and ad libitum starter; CON plus OBE added into MR at 30 mg/kg of body weight (OBE30); and CON plus OBE added into MR at 60 mg/kg of body weight (OBE60). The concentration of GLP-2 was measured at the end of wk 2. Intestinal permeability was measured at the onset of the study and the end of wk 2 and 6, with lactulose and d-mannitol as markers. Treatments did not affect calf growth and starter intake. Compared with CON, administration of OBE60 increased the nutrient-induced response in GLP-2 by about 1 fold and reduced MR intake during the second week of study. Throughout the study, however, all calves had compromised intestinal permeability and a high incidence of diarrhea. The GLP-2 response elicited by OBE60 did not improve intestinal permeability (lactulose-to-d-mannitol ratio) and incidence of diarrhea over the course of the preweaning period. The response in GLP-2 secretion to the administration of OBE reported herein warrants further research efforts to investigate the possibility of improving intestinal integrity through GLP-2 secretion in newborn calves.

Central 5-HT neurotransmission modulates weight loss following gastric bypass surgery in obese individuals.

The cerebral serotonin (5-HT) system shows distinct differences in obesity compared with the lean state. Here, it was investigated whether serotonergic neurotransmission in obesity is a stable trait or changes in association with weight loss induced by Roux-in-Y gastric bypass (RYGB) surgery. In vivo cerebral 5-HT2A receptor and 5-HT transporter binding was determined by positron emission tomography in 21 obese [four men; body mass index (BMI), 40.1 ± 4.1 kg/m(2)] and 10 lean (three men; BMI, 24.6 ± 1.5 kg/m(2)) individuals. Fourteen obese individuals were re-examined after RYGB surgery. First, it was confirmed that obese individuals have higher cerebral 5-HT2A receptor binding than lean individuals. Importantly, we found that higher presurgical 5-HT2A receptor binding predicted greater weight loss after RYGB and that the change in 5-HT2A receptor and 5-HT transporter binding correlated with weight loss after RYGB. The changes in the 5-HT neurotransmission before and after RYGB are in accordance with a model wherein the cerebral extracellular 5-HT level modulates the regulation of body weight. Our findings support that the cerebral 5-HT system contributes both to establish the obese condition and to regulate the body weight in response to RYGB.

Diabetic and nondiabetic patients with nonalcoholic fatty liver disease have an impaired incretin effect and fasting hyperglucagonaemia.

OBJECTIVE: We evaluated whether patients with histologically verified nonalcoholic fatty liver disease (NAFLD) have an impaired incretin effect and hyperglucagonaemia. METHODS: Four groups matched for age, sex and body mass index were studied: (i) 10 patients with normal glucose tolerance and NAFLD; (ii) 10 patients with type 2 diabetes and NAFLD; (iii) eight patients with type 2 diabetes and no liver disease; and (iv) 10 controls. All participants underwent a 50-g oral glucose tolerance test (OGTT) and an isoglycaemic intravenous glucose infusion (IIGI). We determined the incretin effect by relating the beta cell secretory responses during the OGTT and IIGI. Data are presented as medians (interquartile range), and the groups were compared by using the Kruskal-Wallis test. RESULTS: Controls exhibited a higher incretin effect [55% (43-73%)] compared with the remaining three groups (P < 0.001): 39% (44-71%) in the nondiabetic NAFLD patients, 20% (-5-50%) in NAFLD patients with type 2 diabetes, and 2% (-8-6%) in patients with type 2 diabetes and no liver disease. We found fasting hyperglucagonaemia in NAFLD patients with [7.5 pmol L(-1) (6.8-15 pmol L(-1))] and without diabetes [7.5 pmol L(-1) (5.0-8.0 pmol L(-1))]. Fasting glucagon levels were lower but similar in patients with type 2 diabetes and no liver disease [4.5 pmol L(-1) (3.0-6.0 pmol L(-1))] and controls [3.4 pmol L(-1) (1.8-6.0 pmol L(-1) )]. All groups had similar glucagon-like peptide-1 and glucose-dependent insulinotropic polypeptide responses. CONCLUSIONS: Patients with NAFLD have a reduced incretin effect and fasting hyperglucagonaemia, with the latter occurring independently of glucose (in)tolerance.

Peptide YY and glucagon-like peptide-1 contribute to decreased food intake after Roux-en-Y gastric bypass surgery.

BACKGROUND/OBJECTIVES: Exaggerated postprandial secretion of glucagon-like peptide-1 (GLP-1) and peptide YY (PYY) may explain appetite reduction and weight loss after Roux-en-Y gastric bypass (RYGB), but causality has not been established. We hypothesized that food intake decreases after surgery through combined actions from GLP-1 and PYY. GLP-1 actions can be blocked using the GLP-1 receptor antagonist Exendin 9-39 (Ex-9), whereas PYY actions can be inhibited by the administration of a dipeptidyl peptidase-4 (DPP-4) inhibitor preventing the formation of PYY3-36. SUBJECTS/METHODS: Appetite-regulating gut hormones and appetite ratings during a standard mixed-meal test and effects on subsequent ad libitum food intake were evaluated in two studies: in study 1, nine patients with type 2 diabetes were examined prospectively before and 3 months after RYGB with and without Ex-9. In study 2, 12 RYGB-operated patients were examined in a randomized, placebo-controlled, crossover design on four experimental days with: (1) placebo, (2) Ex-9, (3) the DPP-4 inhibitor, sitagliptin, to reduce formation of PYY3-36 and (4) Ex-9/sitagliptin combined. RESULTS: In study 1, food intake decreased by 35% following RYGB compared with before surgery. Before surgery, GLP-1 receptor blockage increased food intake but no effect was seen postoperatively, whereas PYY secretion was markedly increased. In study 2, combined GLP-1 receptor blockage and DPP-4 inhibitor mediated lowering of PYY3-36 increased food intake by ~20% in RYGB patients, whereas neither GLP-1 receptor blockage nor DPP-4 inhibition alone affected food intake, perhaps because of concomitant marked increases in the unblocked hormone. CONCLUSIONS: Blockade of actions from only one of the two L-cell hormones, GLP-1 and PYY3-36, resulted in concomitant increased secretion of the other, probably explaining the absent effect on food intake on these experimental days. Combined blockade of GLP-1 and PYY actions increased food intake after RYGB, supporting that these hormones have a role in decreased food intake postoperatively.

Effects of RYGB on energy expenditure, appetite and glycaemic control: a randomized controlled clinical trial.

OBJECTIVES: Increased energy expenditure (EE) has been proposed as an important mechanism for weight loss following Roux-en-Y gastric bypass (RYGB). However, this has never been investigated in a controlled setting independent of changes in energy balance. Similarly, only few studies have investigated the effect of RYGB on glycaemic control per se. Here, we investigated the effect of RYGB on EE, appetite, glycaemic control and specific signalling molecules compared with a control group in comparable negative energy balance. SUBJECTS/METHODS: Obese normal glucose-tolerant participants were randomized to receive RYGB after 8 (n=14) or 12 weeks (n=14). The protocol included a visit at week 0 and three visits (weeks 7, 11 and 78) where 24-h EE, appetite and blood parameters were assessed. Participants followed a low-calorie diet from weeks 0-11, with those operated at week 12 serving as a control group for those operated at week 8. RESULTS: Compared with controls, RYGB-operated participants had lower body composition-adjusted 24-h EE and basal EE 3 weeks postoperatively (both P<0.05) but EE parameters at week 78 were not different from preoperative values (week 7). Surgery changed the postprandial response of glucagon-like peptide-1 (GLP-1), peptide YY3-36 (PYY), ghrelin, cholecystokinin, fibroblast growth factor-19 and bile acids (all P<0.05). Particularly, increases in GLP-1, PYY and decreases in ghrelin were associated with decreased appetite. None of HOMA-IR (homeostasis model assessment-estimated insulin resistance), Matsuda index, the insulinogenic index, the disposition index and fasting hepatic insulin clearance were different between the groups, but RYGB operated had lower fasting glucose (P<0.05) and the postprandial glucose profile was shifted to the left (P<0.01). CONCLUSIONS: Our data do not support that EE is increased after RYGB. More likely, RYGB promotes weight loss by reducing appetite, partly mediated by changes in gastrointestinal hormone secretion. Furthermore, we found that the early changes in glycaemic control after RYGB is to a large extent mediated by caloric restriction.

Effects of subcutaneous, low-dose glucagon on insulin-induced mild hypoglycaemia in patients with insulin pump treated type 1 diabetes.

AIM: To investigate the dose-response relationship of subcutaneous (s.c.) glucagon administration on plasma glucose and on counter-regulatory hormone responses during s.c. insulin-induced mild hypoglycaemia in patients with type 1 diabetes treated with insulin pumps. METHODS: Eight insulin pump-treated patients completed a blinded, randomized, placebo-controlled study. Hypoglycaemia was induced in the fasting state by an s.c. insulin bolus and, when plasma glucose reached 3.4 mmol/l [95% confidence interval (CI) 3.2-3.5], an s.c. bolus of either 100, 200, 300 µg glucagon or saline was administered. Plasma glucose, counter-regulatory hormones, haemodynamic variables and side effects were measured throughout each study day. Peak plasma glucose level was the primary endpoint. RESULTS: Plasma glucose level increased significantly by a mean (95% CI) of 2.3 (1.7-3.0), 4.2 (3.5-4.8) and 5.0 (4.3-5.6) mmol/l to 6.1 (4.9-7.4), 7.9 (6.4-9.3) and 8.7 (7.8-9.5) vs 3.6 (3.4-3.9) mmol/l (p < 0.001) after the three different glucagon doses as compared with saline, and the increase was neither correlated with weight nor insulin levels. Area under the plasma glucose curve, peak plasma glucose, time to peak plasma glucose and duration of plasma glucose level above baseline were significantly enhanced with increasing glucagon doses; however, these were not significantly different between 200 and 300 µg glucagon. Free fatty acids and heart rates were significantly lower initially after glucagon than after saline injection. Other haemodynamic variables, counter-regulatory hormones and side effects did not differ between interventions. CONCLUSIONS: An s.c. low-dose glucagon bolus effectively restores plasma glucose after insulin overdosing. Further research is needed to investigate whether low-dose glucagon may be an alternative treatment to oral carbohydrate intake for mild hypoglycaemia in patients with type 1 diabetes.

Short-term effects of liraglutide on kidney function and vasoactive hormones in type 2 diabetes: a randomized clinical trial.

AIMS: To investigate the effects of a single dose of 1.2 mg liraglutide, a once-daily glucagon-like peptide-1 (GLP-1) receptor agonist, on key renal variables in patients with type 2 diabetes. METHODS: The study was a placebo-controlled, double-blind, crossover trial in 11 male patients with type 2 diabetes. Measurements included (51) Cr-EDTA plasma clearance estimated glomerular filtration rate (GFR) and MRI-based renal blood flow (RBF), tissue perfusion and oxygenation. RESULTS: Liraglutide had no effect on GFR [95% confidence interval (CI) -6.8 to 3.6 ml/min/1.73 m(2) ] or on RBF (95% CI -39 to 30 ml/min) and did not change local renal blood perfusion or oxygenation. The fractional excretion of lithium increased by 14% (p = 0.01) and sodium clearance tended to increase (p = 0.06). Liraglutide increased diastolic and systolic blood pressure (3 and 6 mm Hg) and heart rate (2 beats per min; all p < 0.05). Angiotensin II (ANG II) concentration decreased by 21% (p = 0.02), but there were no effects on other renin-angiotensin system components, atrial natriuretic peptides (ANPs), methanephrines or excretion of catecholamines. CONCLUSIONS: Short-term liraglutide treatment did not affect renal haemodynamics but decreased the proximal tubular sodium reabsorption. Blood pressure increased with short-term as opposed to long-term treatment. Catecholamine levels were unchanged and the results did not support a GLP-1-ANP axis. ANG II levels decreased, which may contribute to renal protection by GLP-1 receptor agonists.

Effect of chenodeoxycholic acid and the bile acid sequestrant colesevelam on glucagon-like peptide-1 secretion.

AIM: To evaluate the effects of the primary human bile acid, chenodeoxycholic acid (CDCA), and the bile acid sequestrant (BAS) colesevelam, instilled into the stomach, on plasma levels of glucagon-like peptide-1 (GLP-1), glucose-dependent insulinotropic polypeptide, glucose, insulin, C-peptide, glucagon, cholecystokinin and gastrin, as well as on gastric emptying, gallbladder volume, appetite and food intake. METHODS: On four separate days, nine patients with type 2 diabetes, and 10 matched healthy control subjects received bolus instillations of (i) CDCA, (ii) colesevelam, (iii) CDCA + colesevelam or (iv) placebo. At baseline and for 180 min after instillation, blood was sampled. RESULTS: In both the type 2 diabetes group and the healthy control group, CDCA elicited an increase in GLP-1 levels compared with colesevelam, CDCA + colesevelam and placebo, respectively (p < 0.05). The interventions did not affect plasma glucose, insulin or C-peptide concentrations in any of the groups. CDCA elicited a small increase in plasma insulin : glucose ratio compared with colesevelam, CDCA + colesevelam and placebo in both groups. Compared with colesevelam, CDCA + colesevelam and placebo, respectively, CDCA increased glucagon and delayed gastric emptying in both groups. CONCLUSIONS: CDCA increased GLP-1 and glucagon secretion, and delayed gastric emptying. We speculate that bile acid-induced activation of TGR5 on L cells increases GLP-1 secretion, which, in turn, may result in amplification of glucose-stimulated insulin secretion. Furthermore our data suggest that colesevelam does not have an acute effect on GLP-1 secretion in humans.

Cost-effectiveness of Screening for Abdominal Aortic Aneurysm in Combination with Medical Intervention in Patients with Small Aneurysms.

OBJECTIVES: Screening for abdominal aortic aneurysm (AAA) among 65 year old men has been proven cost-effective, but nowadays is conducted partly under new conditions. The prevalence of AAA has decreased, and endovascular aneurysm repair (EVAR) has become the predominant surgical method for AAA repair in many centers. At the Malmö Vascular Center pharmacological secondary prevention with statins, antiplatelet therapy, and blood pressure reduction is initiated and given to all patients with AAA. This study evaluates the cost-effectiveness of AAA screening under the above mentioned conditions. METHODS: This was a Markov cohort simulation. A total of 4,300 65 year old men were invited to annual AAA screening; the attendance rate was 78.3% and AAA prevalence was 1.8%. A Markov model with 11 health states was used to evaluate cost-effectiveness of AAA screening. Background data on rupture risks, costs, and effectiveness of surgical interventions were obtained from the participating unit, the national Swedvasc Registry, and from the scientific literature. RESULTS: The additional costs of the screening strategy compared with no screening were €169 per person and year. The incremental health gain per subject in the screened cohort was 0.011 additional quality adjusted life years (QALYs), corresponding to an incremental cost-effectiveness ratio (ICER) of €15710 per QALY. Assuming a 10% reduction of all cause mortality, the incremental cost of screening was €175 per person and year. The gain per subject in the screened cohort was 0.013 additional QALYs, corresponding to an ICER of €13922 per QALY CONCLUSIONS: AAA screening remains cost-effective according to both the Swedish recommendations and the UK National Institute for Health and Care Excellence recommendations in the new era of lower AAA prevalence, EVAR as the predominant surgical method, and secondary prevention for all AAA patients.

Laser Generated In situ Fenestrations in Dacron Stent Grafts.

OBJECTIVE/BACKGROUND: To evaluate if the creation of laser generated in situ fenestrations in polyester/Dacron stent grafts causes embolization. METHODS: In seven pigs, Dacron stent grafts were implanted from the infrarenal aorta to the right iliac artery. Prior to placing the stent graft, a carotid artery protection filter, with a pore size of 70-200 µm, was placed in the proximal left common iliac artery. An excimer laser catheter was then advanced antegradely through the stent graft and positioned at the level of origin of the left iliac artery. A fenestration was then created with the laser probe. The carotid filter was retrieved and inspected macroscopically with magnifying glasses, for emboli and clot. RESULTS: Seven pigs with a median weight of 90 kg (range 78-98 kg) were tested. The median operating time was 170 minutes. All laser fenestrations were successfully completed. No emboli or clot could be detected in the protection filters. CONCLUSION: Creation of laser generated, in situ fenestrations do not produce macroscopically visible emboli/clot. This might indicate safe usage of laser created fenestrations for endovascular arch repair and left subclavian artery revascularization.