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.

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 post-arginine 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.

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 in T2D patients undergoing RYGB. DESIGN AND SETTING: Follow-up of single-center randomized study. PATIENTS: Thirteen patients with obesity and T2D 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 < 0.001). At 4 weeks, morning cortisol (P < 0.05) and adrenocorticotropin (P = 0.09) were reduced by 20%. Parasympathetic nerve activity (heart rate variability derived) increased at 4 weeks (P < 0.05) and peaked at 24 weeks (P < 0.01). C-reactive protein (CRP) and white blood cells were rapidly reduced (P < 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 < 0.01). Adipocyte volume was reduced by 4 weeks and more markedly at 104 weeks, by about 40% vs baseline (P < 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.

Tissue-specific glucose partitioning and fat content in prediabetes and type 2 diabetes: whole-body PET/MRI during hyperinsulinemia.

OBJECTIVE: To obtain direct quantifications of glucose turnover, volumes and fat content of several tissues in the development of type 2 diabetes (T2D) using a novel integrated approach for whole-body imaging. DESIGN AND METHODS: Hyperinsulinemic-euglycemic clamps and simultaneous whole-body integrated [18F]FDG-PET/MRI with automated analyses were performed in control (n = 12), prediabetes (n = 16) and T2D (n = 13) subjects matched for age, sex and BMI. RESULTS: Whole-body glucose uptake (Rd) was reduced by approximately 25% in T2D vs control subjects, and partitioning to brain was increased from 3.8% of total Rd in controls to 7.1% in T2D. In liver, subcutaneous AT, thigh muscle, total tissue glucose metabolic rates (MRglu) and their % of total Rd were reduced in T2D compared to control subjects. The prediabetes group had intermediate findings. Total MRglu in heart, visceral AT, gluteus and calf muscle was similar across groups. Whole-body insulin sensitivity assessed as glucose infusion rate correlated with liver MRglu but inversely with brain MRglu. Liver fat content correlated with MRglu in brain but inversely with MRglu in other tissues. Calf muscle fat was inversely associated with MRglu only in the same muscle group. CONCLUSIONS: This integrated imaging approach provides detailed quantification of tissue-specific glucose metabolism. During T2D development, insulin-stimulated glucose disposal is impaired and increasingly shifted away from muscle, liver and fat toward the brain. Altered glucose handling in the brain and liver fat accumulation may aggravate insulin resistance in several organs.

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-ß, 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-ß, 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.

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.Trial registration ClinicalTrials.gov Identifier NCT02729246. Date of registration 6 April 2016 - Retrospectively registered https://clinicaltrials.gov/ct2/show/NCT02729246?term=bariglykos&draw=2&rank=1.

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.

[Type B insulin resistance syndrome]. / Typ B-insulinresistenssyndrom ­ sällsynt tillstånd med hög mortalitet.

Type B insulin resistance syndrome (TBIRS) is a very rare autoimmune condition with polyclonal autoantibodies directed against the insulin receptor, which results in severe and refractory hyperglycemia and high mortality. Described here is a patient who, within a few months after the onset of an autoimmune type 1 diabetes, increased her insulin requirements more than 20-fold, and despite this having a considerable difficulty maintaining  her P-glucose < 40-60 mmol/L. On suspicion of TBIRS the patient was started on tapering glucocorticoids to overcome the autoimmune insulin receptor blockade, resulting in an immediate and dramatic effect. Within days insulin requirements decreased by 80-90 %, and the P-glucose stabilized around 7-8 mmol/L. 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 with temporarily remarkable effect. Mixed and transient results were seen with rituximab, mycophenolic acid and bortezomib but glycemic control has remained suboptimal. Lack of compliance and recurrent infections may have contributed to this.

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

SUMMARY: 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. LEARNING POINTS: Type B insulin resistance syndrome (TBIRS) is a very rare autoimmune disorder with acquired polyclonal autoantibodies against the insulin receptor, resulting in severe and refractory hyperglycemia. We describe here a young patient in whom, a few months after the onset of a regular autoimmune diabetes, insulin requirements in a short time increased more than 20-fold, but despite this, the plasma glucose level could be kept at <40-60 mmol/L only with considerable difficulty. Did this patient have TBIRS? On suspicion of TBIRS, the patient was started on tapering 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. 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 with temporarily remarkable effect. TBIRS should be considered in diabetic patients whose glycemia and/or insulin requirements are inexplicably and dramatically increased.

Rapid changes in neuroendocrine regulation may contribute to reversal of type 2 diabetes after gastric bypass surgery.

OBJECTIVE: To explore the role of hormones and the autonomic nervous system in the rapid remission of diabetes after Roux-en-Y Gastric Bypass (RYGB). RESEARCH DESIGN AND METHODS: Nineteen obese patients with type 2 diabetes, 7 M/12 F, were randomized (2:1) to RYGB or standard-of-care medical treatment (control). At baseline and 4 and 24 weeks post surgery, fasting blood sampling, OGTT, intravenous arginine challenge, and heart-rate variability (HRV) assessments were performed. RESULTS: At both 4 and 24 weeks post-RYGB the following effects were found: arginine-stimulated insulin secretion was reduced. GLP-1, GIP, and glucagon rise during OGTT was enhanced. IGF-1 and GH levels increased. In addition, total HRV and spectral components PLF (power of low frequency) and PHF (power of high frequency) increased. At 4 weeks, morning cortisol was lower than baseline and 24 weeks. At 24 weeks, NEFA levels during OGTT, and the PLF/PHF ratio decreased. None of these changes were seen in the control group. CONCLUSIONS: There were rapid changes within 4 weeks after RYGB: signs of enhanced parasympathetic nerve activity, reduced morning cortisol, and enhanced incretin and glucagon responses to glucose. The findings suggest that neurohormonal mechanisms can contribute to the rapid improvement of insulin resistance and glycemia following RYGB in type 2 diabetes.

Early Changes in Adipose Tissue Morphology, Gene Expression, and Metabolism After RYGB in Patients With Obesity and T2D.

CONTEXT: Roux-en-Y gastric bypass (RYGB) surgery effectively prevents or treats type 2 diabetes (T2D). Adipose tissue (AT) mechanisms may be of importance. OBJECTIVE: To assess the relationship between early changes in whole-body and AT metabolism in surgically treated patients with T2D. DESIGN AND SETTING: A randomized single-center study. PATIENTS: Nineteen patients with T2D with body mass index 30 to 45 kg/m2. INTERVENTIONS: Thirteen patients were assessed at baseline and 4 and 24 weeks after RYGB (preceded by a 4-week low-calorie diet) and compared with 6 control patients continuing standard medical treatment: oral glucose tolerance test, subcutaneous AT biopsies for gene expression, adipocyte size, glucose uptake, lipolysis, and insulin action. RESULTS: At 4 and 24 weeks post-RYGB, all patients but one had stopped diabetes medication. Fasting glucose, HbA1c, and insulin levels decreased and the Matsuda index increased compared with baseline (P < 0.01 for all), indicating improved whole-body insulin sensitivity. Mean adipocyte size significantly reduced, more at 4 than at 24 weeks; at 4 weeks, glucose uptake per adipocyte was lowered, and isoproterenol-stimulated lipolysis tended to increase, whereas the fold insulin effects on glucose uptake and lipolysis were unchanged. Expression of genes involved in fatty acid oxidation, CPT1b and adiponectin, was increased at 4 weeks, whereas leptin and E2F1 (involved in cell proliferation) were reduced (P < 0.05 for all). CONCLUSION: Glycemic control and in vivo insulin sensitivity improved 4 weeks after RYGB, but adipocyte insulin sensitivity did not change despite a marked reduction in adipocyte size. Thus, mechanisms for a rapid improvement of T2D after RYGB may occur mainly in other tissues than adipose.

Glucagon Levels During Short-Term SGLT2 Inhibition Are Largely Regulated by Glucose Changes in Patients With Type 2 Diabetes.

Context: The mechanism mediating sodium glucose cotransporter-2 (SGLT2) inhibitor-associated increase in glucagon levels is unknown. Objective: To assess short-term effects on glucagon, other hormones, and energy substrates after SGLT2 inhibition and whether such effects are secondary to glucose lowering. The impact of adding a dipeptidyl peptidase-4 inhibitor was addressed. Design, Setting, and Patients: A phase 4, single-center, randomized, three-treatment crossover, open-label study including 15 patients with type 2 diabetes treated with metformin. Interventions: Patients received a single-dose of dapagliflozin 10 mg accompanied by the following in randomized order: isoglycemic clamp (experiment DG); saline infusion (experiment D); or saxagliptin 5 mg plus saline infusion (experiment DS). Directly after 5-hour infusions, a 2-hour oral glucose tolerance test (OGTT) was performed. Results: Glucose and insulin levels were stable in experiment DG and decreased in experiment D [P for difference (Pdiff) < 0.001]. Glucagon-to-insulin ratio (Pdiff < 0.001), and levels of glucagon (Pdiff < 0.01), nonesterified fatty acids (Pdiff < 0.01), glycerol (Pdiff < 0.01), and ß-OH-butyrate (Pdiff < 0.05) were lower in DG vs D. In multivariate analysis, change in glucose level was the main predictor of change in glucagon level. In DS, glucagon and active GLP-1 levels were higher than in D, but glucose and insulin levels did not differ. During OGTT, glucose levels rose less and glucagon levels fell more in DS vs D. Conclusion: The degree of glucose lowering markedly contributed to regulation of glucagon and insulin secretion and to lipid mobilization during short-term SGLT2 inhibition.

FKBP5 expression in human adipose tissue: potential role in glucose and lipid metabolism, adipogenesis and type 2 diabetes.

PURPOSE: Here, we explore the involvement of FKBP51 in glucocorticoid-induced insulin resistance (IR) in human subcutaneous adipose tissue (SAT), including its potential role in type 2 diabetes (T2D). Moreover, we assess the metabolic effects of reducing the activity of FKBP51 using the specific inhibitor SAFit1. METHODS: Human SAT was obtained by needle biopsies of the lower abdominal region. FKBP5 gene expression was assessed in fresh SAT explants from a cohort of 20 T2D subjects group-wise matched by gender, age and BMI to 20 non-diabetic subjects. In addition, human SAT was obtained from non-diabetic volunteers (20F/9M). SAT was incubated for 24 h with or without the synthetic glucocorticoid dexamethasone and SAFit1. Incubated SAT was used to measure the glucose uptake rate in isolated adipocytes. RESULTS: FKBP5 gene expression levels in SAT positively correlated with several indices of IR as well as glucose area under the curve during oral glucose tolerance test (r = 0.33, p < 0.05). FKBP5 gene expression levels tended to be higher in T2D subjects compared to non-diabetic subjects (p = 0.088). Moreover, FKBP5 gene expression levels were found to inversely correlate with lipolytic, lipogenic and adipogenic genes. SAFit1 partly prevented the inhibitory effects of dexamethasone on glucose uptake. CONCLUSIONS: FKBP5 gene expression in human SAT tends to be increased in T2D subjects and is related to elevated glucose levels. Moreover, FKBP5 gene expression is inversely associated with the expression of lipolytic, lipogenic and adipogenic genes. SAFit1 can partly prevent glucose uptake impairment by glucocorticoids, suggesting that FKBP51 might be a key factor in glucocorticoid-induced IR.

Altered Glucose Uptake in Muscle, Visceral Adipose Tissue, and Brain Predict Whole-Body Insulin Resistance and may Contribute to the Development of Type 2 Diabetes: A Combined PET/MR Study.

We assessed glucose uptake in different tissues in type 2 diabetes (T2D), prediabetes, and control subjects to elucidate its impact in the development of whole-body insulin resistance and T2D. Thirteen T2D, 12 prediabetes, and 10 control subjects, matched for age and BMI, underwent OGTT and abdominal subcutaneous adipose tissue (SAT) biopsies. Integrated whole-body 18F-FDG PET and MRI were performed during a hyperinsulinemic euglycemic clamp to asses glucose uptake rate (MRglu) in several tissues. MRglu in skeletal muscle, SAT, visceral adipose tissue (VAT), and liver was significantly reduced in T2D subjects and correlated positively with M-values (r=0.884, r=0.574, r=0.707 and r=0.403, respectively). Brain MRglu was significantly higher in T2D and prediabetes subjects and had a significant inverse correlation with M-values (r=-0.616). Myocardial MRglu did not differ between groups and did not correlate with the M-values. A multivariate model including skeletal muscle, brain and VAT MRglu best predicted the M-values (adjusted r2=0.85). In addition, SAT MRglu correlated with SAT glucose uptake ex vivo (r=0.491). In different stages of the development of T2D, glucose uptake during hyperinsulinemia is elevated in the brain in parallel with an impairment in peripheral organs. Impaired glucose uptake in skeletal muscle and VAT together with elevated glucose uptake in brain were independently associated with whole-body insulin resistance, and these tissue-specific alterations may contribute to T2D development.

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 24 weeks. Here, we examined these effects over 1 year in obese adults without diabetes. MATERIALS AND METHODS: Obese adults without diabetes (N = 50; aged 18-70 years; body mass index, 30-45 kg/m2 ) were initially randomized to double-blind oral dapagliflozin 10 mg once daily plus subcutaneous long-acting exenatide 2 mg once weekly or to placebo. They entered an open-label extension from 24 to 52 weeks 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 52 weeks of treatment. At baseline, mean body weight was 104.6 kg, and 73.5% of participants had prediabetes (impaired fasting glucose or impaired glucose tolerance). Reductions with dapagliflozin + exenatide at 24 weeks were sustained at 52 weeks, respectively, for body weight (-4.5 and -5.7 kg), total adipose tissue volume (-3.8 and -5.3 L), proportion with prediabetes (34.8% and 35.3%), and SBP (-9.8 and -12.0 mm Hg). Effects on body weight, SBP and glycaemia at 52 weeks with placebo → dapagliflozin + 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 52 weeks and was well tolerated in obese adults without diabetes.

Role of cannabinoid receptor 1 in human adipose tissue for lipolysis regulation and insulin resistance.

We recently showed that the peripheral cannabinoid receptor type 1 (CNR1) gene is upregulated by the synthetic glucocorticoid dexamethasone. CNR1 is highly expressed in the central nervous system and has been a drug target for the treatment of obesity. Here we explore the role of peripheral CNR1 in states of insulin resistance in human adipose tissue. Subcutaneous adipose tissue was obtained from well-controlled type 2 diabetes subjects and controls. Subcutaneous adipose tissue gene expression levels of CNR1 and endocannabinoid synthesizing and degrading enzymes were assessed. Furthermore, paired human subcutaneous adipose tissue and omental adipose tissue from non-diabetic volunteers undergoing kidney donation or bariatric surgery, was incubated with or without dexamethasone. Subcutaneous adipose tissue obtained from volunteers through needle biopsy was incubated with or without dexamethasone and in the presence or absence of the CNR1-specific antagonist AM281. CNR1 gene and protein expression, lipolysis and glucose uptake were evaluated. Subcutaneous adipose tissue CNR1 gene expression levels were 2-fold elevated in type 2 diabetes subjects compared with control subjects. Additionally, gene expression levels of CNR1 and endocannabinoid-regulating enzymes from both groups correlated with markers of insulin resistance. Dexamethasone increased CNR1 expression dose-dependently in subcutaneous adipose tissue and omental adipose tissue by up to 25-fold. Dexamethasone pre-treatment of subcutaneous adipose tissue increased lipolysis rate and reduced glucose uptake. Co-incubation with the CNR1 antagonist AM281 prevented the stimulatory effect on lipolysis, but had no effect on glucose uptake. CNR1 is upregulated in states of type 2 diabetes and insulin resistance. Furthermore, CNR1 is involved in glucocorticoid-regulated lipolysis. Peripheral CNR1 could be an interesting drug target in type 2 diabetes and dyslipidemia.

Impaired adipose tissue lipid storage, but not altered lipolysis, contributes to elevated levels of NEFA in type 2 diabetes. Degree of hyperglycemia and adiposity are important factors.

BACKGROUND: Elevated levels of circulating non-esterified fatty acids (NEFA) mediate many adverse metabolic effects. In this work we aim to determine the impact of type 2 diabetes (T2D), glycemic control and obesity on lipolysis regulation. DESIGN AND PARTICIPANTS: 20 control and 20 metformin-treated T2D subjects were matched for sex (10M/10 F), age (58±11 vs 58±9 y) and BMI (30.8±4.6 vs 30.7±4.9kg/m2). In vivo lipolysis was assessed during a 3h-OGTT with plasma glycerol and NEFA levels. Subcutaneous adipose tissue (SAT) biopsies were obtained to measure mRNA and metabolite levels of factors related to lipolysis and lipid storage and to assess in vitro lipolysis in isolated subcutaneous adipocytes. RESULTS: Plasma NEFA AUC during the OGTT where higher 30% (P=0.005) in T2D than in control subjects, but plasma glycerol AUC and subcutaneous adipocyte lipolysis in vitro were similar, suggesting that adipose tissue lipolysis is not altered. Expression in SAT of genes involved in lipid storage (FABP4, DGAT1, FASN) were reduced in T2D subjects compared with controls, but no differences were seen for genes involved in lipolysis. T2D subjects had elevated markers of beta-oxidation, α-hydroxybutyrate (1.4-fold, P<0.01) and ß-hydroxybutyrate (1.7-fold, P<0.05) in plasma. In multivariate analysis, HbA1c, visceral adipose tissue volume and sex (male) were significantly associated with NEFA AUC in T2D subjects. CONCLUSIONS: In T2D subjects, NEFA turnover is impaired, but not due to defects in lipolysis or lipid beta-oxidation. Impaired adipose NEFA re-esterification or de novo lipogenesis is likely to contribute to higher NEFA plasma levels in T2D. The data suggest that hyperglycemia and adiposity are important contributing factors for the regulation of plasma NEFA concentrations.