Bariatric surgery as treatment of type 2 diabetes – clinical and mechanistic aspects

Bariatric surgery can rapidly improve glycemic control and cardiovascular risk factors in patients with T2D and obesity. These improvements appear to be partly independent of weight loss, however, the underlying mechanisms remain incompletely understood. A randomized controlled trial was designed where 19 patients with obesity and T2D were either operated with a  Roux-en-Y gastric bypass (RYGB) operation or continued with standard-of-care treatment and followed up for 2 years, providing the data for Paper I-III. In paper I, we focused on changes in whole-body glucose metabolism in relation to changes in adipose tissue metabolism and morphology. We observed an early adipose tissue remodeling and a reduction in adipocyte size that however, did not correlate to the early improvements in metabolic control. In paper II, we analyzed the neuroendocrine changes after RYGB. We observed changes within 4 weeks with signs of enhanced parasympathetic outlow, reduced morning cortisol, and enhanced incretin and glucagon responses to glucose, suggesting that neurohormonal mechanisms can contribute to the rapid improvement of insulin resistance and glycemia following RYGB in T2D. In paper III the patients from the RYGB group were interviewed 2 years after surgery to examine the effects of surgery on health-related quality of life (HRQoL). We found that the improved HRQoL after RYGB was not explained specifically by the magnitude of weight loss, but rather by the participants achieving a state of union between body and consciousness. In paper IV, we compared changes in circulating cytokine and adipokine levels in obese patients with- and without T2D. We observed that the cytokine profile of these patients is altered when compared to lean healthy control subjects and persist to a large extent after RYGB despite the weight loss and improved metabolic status. In conclusion, we observed that in the early post-operative period, neurohormonal changes appear to be more important than adipose tissue changes in improving insulin sensitivity and leading to diabetes remission. In the qualitative part of our study, we observed that the improved HRQoL was not solely explained by weight los

Bariatric surgery as treatment of type 2 diabetes – clinical and mechanistic aspects

Bariatric surgery can rapidly improve glycemic control and cardiovascular risk factors in patients with T2D and obesity. These improvements appear to be partly independent of weight loss, however, the underlying mechanisms remain incompletely understood. A randomized controlled trial was designed where 19 patients with obesity and T2D were either operated with a  Roux-en-Y gastric bypass (RYGB) operation or continued with standard-of-care treatment and followed up for 2 years, providing the data for Paper I-III. In paper I, we focused on changes in whole-body glucose metabolism in relation to changes in adipose tissue metabolism and morphology. We observed an early adipose tissue remodeling and a reduction in adipocyte size that however, did not correlate to the early improvements in metabolic control. In paper II, we analyzed the neuroendocrine changes after RYGB. We observed changes within 4 weeks with signs of enhanced parasympathetic outlow, reduced morning cortisol, and enhanced incretin and glucagon responses to glucose, suggesting that neurohormonal mechanisms can contribute to the rapid improvement of insulin resistance and glycemia following RYGB in T2D. In paper III the patients from the RYGB group were interviewed 2 years after surgery to examine the effects of surgery on health-related quality of life (HRQoL). We found that the improved HRQoL after RYGB was not explained specifically by the magnitude of weight loss, but rather by the participants achieving a state of union between body and consciousness. In paper IV, we compared changes in circulating cytokine and adipokine levels in obese patients with- and without T2D. We observed that the cytokine profile of these patients is altered when compared to lean healthy control subjects and persist to a large extent after RYGB despite the weight loss and improved metabolic status. In conclusion, we observed that in the early post-operative period, neurohormonal changes appear to be more important than adipose tissue changes in improving insulin sensitivity and leading to diabetes remission. In the qualitative part of our study, we observed that the improved HRQoL was not solely explained by weight los

The effects of bisphenol A and bisphenol S on adipokine expression and glucose metabolism in human adipose tissue

Purpose The environmental endocrine disruptors, bisphenol A (BPA) and bisphenol S (BPS) are associated with the development of type 2 diabetes. We aim to study the effects of BPA or BPS exposure on adipokine expression in human adipose tissue and on adipocyte glucose uptake. Methods Human subcutaneous adipose tissue was treated for 24 or 72 h with environmentally-relevant and supraphysiological concentrations of BPA or BPS (1–104 nM). Following exposure, gene expression of proinflammatory cytokines, adipokines, and estrogen receptors was measured in adipose tissue. Glucose uptake and the insulin signalling pathway were analyzed in isolated adipocytes following adipose tissue culture with BPA for 24 h. Results Adipose tissue treated with BPA for 24 h had reduced expression of the proinflammatory genes (IL6, IL1B, TNFA) and adipokines (ADIPOQ, FABP4). BPA and BPS had no effect on the expression of other proinflammatory genes (IL33), adipokines (LEP), or receptors (ESR1, ESR2) after 72-h exposure. Adipose tissue treated with environmentally-relevant concentrations of BPA for 24 h had reduced insulin-stimulated glucose uptake, without altered gene and protein levels of key insulin signalling pathway markers. Conclusions We found that human adipose tissue treated with environmentally-relevant concentrations of BPA for 24 h, but not BPS, reduced expression of proinflammatory genes and adipokines. Furthermore, BPA reduced glucose uptake in adipocytes independently of insulin signalling. Such mechanisms can contribute to the development of insulin resistance associated with BPA exposure

Quality of life after gastric bypass surgery in patients with type 2 diabetes : patients' experiences during 2 years of follow-up

Background To examine the effects of gastric bypass surgery on health-related quality of life (HRQoL) in obese patients with type 2 diabetes, and to investigate their experiences of life adjustments using quantitative and qualitative methods. Methods Thirteen patients with type 2 diabetes and obesity, (body mass index, BMI > 30 kg/m2), participating in a randomized clinical trial, completed this sub-study. HRQoL was evaluated before, and at 6 months and 2 years after gastric bypass surgery, using the RAND- 36-item health survey. At 2 years, interviews for in-depth analysis of HRQoL changes were performed. Results Significant improvement was observed from baseline to 6 months for 2 of the eight health concepts, general health, and emotional well-being. At 2 years, improvements were also seen in physical functioning, energy/fatigue, as well as sustained improvements in general health and emotional well-being. Multiple regression analyses showed mostly non-significant associations between the magnitude of decrease in weight, BMI, and HbA1c during follow-up and improvement in HRQoL. The analyses from qualitative interviews supported a common latent theme “Finding a balance between the experience of the new body weight and self-confidence”. Conclusions The improved HRQoL after gastric bypass surgery in obese patients with type 2 diabetes was not explained specifically by the magnitude of weight loss, but rather by the participants achieving a state of union between body and consciousness

Complementary elements of support after gastric-bypass surgery perceived by adults with previous type 2 diabetes : A qualitative study 2 years after bariatric surgery

Bariatric surgery is the most medically and cost-effective treatment for adults with obesity and type 2 diabetes mellitus (T2DM). Our findings suggest initial improvements in health-related quality of life that may decline as support from follow-up care ends. How patients experience long-term support is not well described. This study therefore aimed to investigate how adults with previous T2DM perceived different sources of support 2 years after bariatric surgery. In this qualitative study, individual interviews were conducted with 13 adults (10 women) 2 years after surgery. Using thematic analysis, one overarching theme (compiling complementary elements of support after gastric-bypass surgery), four themes and nine subthemes emerged. The results show that support was given and received from various sources, support needs varied over time depending on where the patient was in the process and that the sources of support were complementary. To conclude, our results show that support needs change in adults who have undergone bariatric surgery. Long-term professional and day-to-day support from family and other networks are essential and complementary elements of support. Healthcare staff should consider these findings, especially during the early follow-up period

Dapagliflozin once daily plus exenatide once weekly in obese adults without diabetes : Sustained reductions in body weight, glycaemia and blood pressure over 1 year

Aims: Dapagliflozin and exenatide reduce body weight by differing mechanisms. Dual therapy with these agents reduces body weight, adipose tissue volume, glycaemia and systolic blood pressure (SBP) over 24weeks. Here, we examined these effects over 1year in obese adults without diabetes. Materials and methods: Obese adults without diabetes (N=50; aged 18-70years; body mass index, 30-45kg/m(2)) were initially randomized to double-blind oral dapagliflozin 10mg once daily plus subcutaneous long-acting exenatide 2mg once weekly or to placebo. They entered an open-label extension from 24 to 52weeks during which all participants received active treatment. Results: Of the original 25 dapagliflozin+exenatide-treated and 25 placebo-treated participants, respectively, 21 (84%) and 17 (68%) entered the open-label period and 16 (64%) and 17 (68%) completed 52weeks of treatment. At baseline, mean body weight was 104.6kg, and 73.5% of participants had prediabetes (impaired fasting glucose or impaired glucose tolerance). Reductions with dapagliflozin+exenatide at 24weeks were sustained at 52weeks, respectively, for body weight (-4.5 and -5.7kg), total adipose tissue volume (-3.8 and -5.3L), proportion with prediabetes (34.8% and 35.3%), and SBP (-9.8 and -12.0mm Hg). Effects on body weight, SBP and glycaemia at 52weeks with placebodapagliflozin+exenatide were similar to those observed with continuation of dapagliflozin+exenatide. Nausea and injection-site reactions were more frequent with dapagliflozin+exenatide than with placebo and diminished over time. Safety and tolerability were similar to that in previous diabetes trials with these agents. No clear difference in adverse event-related withdrawals between placebo and active treatment periods was observed. Conclusions: Dapagliflozin+exenatide dual therapy produced sustained reductions in body weight, prediabetes and SBP over 52weeks and was well tolerated in obese adults without diabetes

Type B insulin resistance syndrome in a patient with type 1 diabetes

Type B insulin resistance syndrome (TBIRS) is a very rare autoimmune disorder with polyclonal autoantibodies against the insulin receptor, resulting in severe and refractory hyperglycemia. Described here is a patient who within a few months after the onset of autoimmune type 1 diabetes increased her insulin requirements more than 20-fold; despite this she had considerable difficulty maintaining a plasma glucose value of <40-60 mmol/L (720-1100 mg/dL). On suspicion of TBIRS, the patient was started on tapering dose of glucocorticoids to overcome the autoimmune insulin receptor blockade, resulting in an immediate and pronounced effect. Within days, insulin requirements decreased by 80-90% and plasma glucose stabilized around 7-8 mmol/L (126-144 mg/dL). The presence of antibodies to the insulin receptor was detected by immunoprecipitation and binding assays. After a 4-month remission on low maintenance dose prednisolone, the patient relapsed, which required repeated plasmaphereses and immune column treatments with temporarily remarkable effect. Mixed and transient results were seen with rituximab, mycophenolic acid and bortezomib, but the glycemic status remained suboptimal. Lack of compliance and recurrent infections may have contributed to this

Response of multiple hormones to glucose and arginine challenge in T2DM after gastric bypass

Purpose: In patients with type 2 diabetes mellitus (T2DM), Roux-en-Y gastric bypass (RYGB) leads to beneficial metabolic adaptations, including enhanced incretin secretion, beta-cell function, and systemic insulin sensitivity. We explored the impact of RYGB on pituitary, pancreatic, gut hormones, and cortisol responses to parenteral and enteral nutrient stimulation in patients with obesity and T2DM with repeated sampling up to 2 years after intervention. Methods: We performed exploratory post hoc analyses in a previously reported randomized trial. Levels of adrenocorticotropic hormone (ACTH), cortisol, growth hormone (GH), glucagon-like peptide 1 (GLP-1), glucose-dependent insulinotropic peptide (GIP), peptide YY (PYY), ACTH, insulin, and glucagon were measured in 13 patients with T2DM and obesity at four different visits: before and 4, 24, and 104 weeks after RYGB; and in three sequential conditions on the same day: fasting, intravenous arginine challenge, and OGTT. Results: RYGB surprisingly induced a rise in ACTH, cortisol, and GH levels upon an oral glucose load, together with enhanced GLP-1 and PYY responses. Fasting and postarginine GH levels were higher after RYGB, whereas insulin, glucagon, GLP-1, GIP, and cortisol were lower. These endocrine adaptations were seen as early as 4 weeks after surgery and were maintained for up to 2 years. Conclusion: These findings indicate adaptations of glucose sensing mechanisms and responses in multiple endocrine organs after RYGB, involving the gut, pancreatic islets, the pituitary gland, the adrenals, and the brain

Changes in Circulating Cytokines and Adipokines After RYGB in Patients with and without Type 2 Diabetes

Objective This study aimed to compare cytokine and adipokine levels in patients with obesity with and without type 2 diabetes (T2D) at baseline and 6 months after Roux‐en‐Y gastric bypass (RYGB) with healthy controls. Methods A total of 34 patients (21 with T2D) with BMI of 30 to 45 kg/m2 were compared with 25 healthy controls without obesity. Cytokines, adipokines, and peptides of relevance for inflammation and metabolism were analyzed in plasma. Results Significant decreases in weight and glycated hemoglobin A1c were observed. At baseline, interleukin‐6 (IL‐6), IFN‐β, IL‐18, leptin, and hepatocyte growth factor were higher in all patients with obesity compared with healthy controls. In patients without T2D, TNF‐α, IL‐1α, IL‐2, IL‐15, and visfatin were also increased, whereas bone morphogenic protein‐4 was decreased. Following RYGB, IL‐6 and hepatocyte growth factor were still increased in both groups compared with controls. In T2D patients, IFN‐β, IL‐27, IL‐1α, IL‐2, regenerating islet‐derived protein 3A, visfatin, and osteopontin were found to be increased. In patients without T2D, TNF‐α, IL‐1α, IL‐2, IL‐15, leptin, and visfatin remained increased. Conclusions The altered cytokine profile of patients with obesity persisted after RYGB despite large weight loss and improved metabolic status, thus reflecting an inherent inflammatory state.Title in thesis list of papers: Changes in circulating cytokines and adipokines after gastric bypass surgery in patients with obesity with and without type 2 diabetes</p

Time course of metabolic, neuroendocrine, and adipose effects during 2 years of follow-up after gastric bypass in patients with type 2 diabetes

Context: Roux-en-Y gastric bypass surgery (RYGB) markedly improves glycemia in patients with type 2 diabetes (T2D), but underlying mechanisms and changes over time are incompletely understood. Objective: Integrated assessment of neuroendocrine and metabolic changes over time inT2D patients undergoing RYGB. Design and Setting: Follow-up of single-center randomized study. Patients: Thirteen patients with obesity andT2D compared to 22 healthy subjects. Interventions: Blood chemistry, adipose biopsies, and heart rate variability were obtained before and 4, 24, and 104 weeks post-RYGB. Results: After RYGB, glucose-lowering drugs were discontinued and hemoglobin A1c fell from mean 55 to 41 mmol/mol by 104 weeks (P &lt; 0.001). At 4 weeks, morning cortisol (P &lt; 0.05) and adrenocorticotropin (P = 0.09) were reduced by 20%. Parasympathetic nerve activity (heart rate variability derived) increased at 4 weeks (P &lt; 0.05) and peaked at 24 weeks (P &lt; 0.01). C-reactive protein (CRP) and white blood cells were rapidly reduced (P &lt; 0.01). At 104 weeks, basal and insulin-stimulated adipocyte glucose uptake increased by 3-fold vs baseline and expression of genes involved in glucose transport, fatty acid oxidation, and adipogenesis was upregulated (P &lt; 0.01). Adipocyte volume was reduced by 4 weeks and more markedly at 104 weeks, by about 40% vs baseline (P &lt; 0.01). Conclusions: We propose this order of events: (1) rapid glucose lowering (days); (2) attenuated cortisol axis activity and inflammation and increased parasympathetic tone (weeks); and (3) body fat and weight loss, increased adipose glucose uptake, and whole-body insulin sensitivity (months-years; similar to healthy controls).Thus, neuroendocrine pathways can partly mediate early glycemic improvement after RYGB, and adipose factors may promote long-term insulin sensitivity and normoglycemia