Glucagon-like peptide 1 receptor is a T cell-negative costimulatory molecule.

Glucagon-like peptide-1 receptor (GLP-1R) is a key regulator of glucose metabolism known to be expressed by pancreatic ß cells. We herein investigated the role of GLP-1R on T lymphocytes during immune response. Our data showed that a subset of T lymphocytes expresses GLP-1R, which is upregulated during alloimmune response, similarly to PD-1. When mice received islet or cardiac allotransplantation, an expansion of GLP-1Rpos T cells occurred in the spleen and was found to infiltrate the graft. Additional single-cell RNA sequencing (scRNA-seq) analysis conducted on GLP-1Rpos and GLP-1Rneg CD3+ T cells unveiled the existence of molecular and functional dissimilarities between both subpopulations, as the GLP-1Rpos are mainly composed of exhausted CD8 T cells. GLP-1R acts as a T cell-negative costimulatory molecule, and GLP-1R signaling prolongs allograft survival, mitigates alloimmune response, and reduces T lymphocyte graft infiltration. Notably, GLP-1R antagonism triggered anti-tumor immunity when tested in a preclinical mouse model of colorectal cancer.

Hyperglycemia impairs EAAT2 glutamate transporter trafficking and glutamate clearance in islets of Langerhans: implications for type 2 diabetes pathogenesis and treatment.

Pancreatic endocrine cells employ a sophisticated system of paracrine and autocrine signals to synchronize their activities, including glutamate, which controls hormone release and ß-cell viability by acting on glutamate receptors expressed by endocrine cells. We here investigate whether alteration of the excitatory amino acid transporter 2 (EAAT2), the major glutamate clearance system in the islet, may occur in type 2 diabetes mellitus and contribute to ß-cell dysfunction. Increased EAAT2 intracellular localization was evident in islets of Langerhans from T2DM subjects as compared with healthy control subjects, despite similar expression levels. Chronic treatment of islets from healthy donors with high-glucose concentrations led to the transporter internalization in vesicular compartments and reduced [H3]-d-glutamate uptake (65 ± 5% inhibition), phenocopying the findings in T2DM pancreatic sections. The transporter relocalization was associated with decreased Akt phosphorylation protein levels, suggesting an involvement of the phosphoinositide 3-kinase (PI3K)/Akt pathway in the process. In line with this, PI3K inhibition by a 100-µM LY294002 treatment in human and clonal ß-cells caused the transporter relocalization in intracellular compartments and significantly reduced the glutamate uptake compared to control conditions, suggesting that hyperglycemia changes the trafficking of the transporter to the plasma membrane. Upregulation of the glutamate transporter upon treatment with the antibiotic ceftriaxone rescued hyperglycemia-induced ß-cells dysfunction and death. Our data underscore the significance of EAAT2 in regulating islet physiology and provide a rationale for potential therapeutic targeting of this transporter to preserve ß-cell survival and function in diabetes.NEW & NOTEWORTHY The glutamate transporter SLC1A2/excitatory amino acid transporter 2 (EAAT2) is expressed on the plasma membrane of pancreatic ß-cells and controls islet glutamate clearance and ß-cells survival. We found that the EAAT2 membrane expression is lost in the islets of Langerhans from type 2 diabetes mellitus (T2DM) patients due to hyperglycemia-induced downregulation of the phosphoinositide 3-kinase/Akt pathway and modification of its intracellular trafficking. Pharmacological rescue of EAAT2 expression prevents ß-cell dysfunction and death, suggesting EAAT2 as a new potential target of intervention in T2DM.

Type 2 diabetes mellitus pharmacological remission with dapagliflozin plus oral semaglutide.

Dapagliflozin, a sodium-glucose co-transporter-2 inhibitor and semaglutide, a glucagon-like peptide 1 receptor agonist, have both demonstrated efficacy in glycemic control, reducing blood pressure, body weight, risk of renal and heart failure in type 2 diabetes mellitus. In this observational, real-world, study we aimed to investigate the efficacy of the combination therapy with those two agents over glycemic control. We thus obtained the data of 1335 patients with type 2 diabetes followed by 11 Diabetes centers in Lombardia, Italy. A group of 443 patients was treated with dapagliflozin alone, the other group of 892 patients was treated with the combination therapy of dapagliflozin plus oral semaglutide. We analyzed changes in glycated hemoglobin from baseline to 6 months of follow-up, as well as changes in fasting glycemia, body weight, body mass index, systolic and diastolic pressure, heart rate, creatinine, estimated glomerular filtration rate and albuminuria. Both groups of patients showed an improvement of glycometabolic control after 6 months of treatment; indeed, the treatment with dapagliflozin plus oral semaglutide showed a reduction of glycated hemoglobin of 1.2% as compared to the 0.5% reduction observed in the dapagliflozin alone group. Significant changes were observed in body mass index, fasting plasmatic glucose, blood pressure, total cholesterol, LDL and albumin to creatinine ratio, with a high rate (55%) of near-normalization of glycated hemoglobin. Our real world data confirmed the potential of the oral combination therapy dapagliflozin with semaglutide in inducing pharmacological remission of type 2 diabetes mellitus.

Mechanisms of action of incretin receptor based dual- and tri-agonists in pancreatic islets.

Simultaneous activation of the incretin G-protein-coupled receptors (GPCRs) via unimolecular dual-receptor agonists (UDRA) has emerged as a new therapeutic approach for type 2 diabetes. Recent studies also advocate triple agonism with molecules also capable of binding the glucagon receptor. In this scoping review, we discuss the cellular mechanisms of action (MOA) underlying the actions of these novel and therapeutically important classes of peptide receptor agonists. Clinical efficacy studies of several UDRAs have demonstrated favorable results both as monotherapies and when combined with approved hypoglycemics. Although the additive insulinotropic effects of dual glucagon-like peptide-1 receptor (GLP-1R) and glucose-dependent insulinotropic peptide receptor (GIPR) agonism were anticipated based on the known actions of either glucagon-like peptide-1 (GLP-1) or glucose-dependent insulinotropic peptide (GIP) alone, the additional benefits from GCGR were largely unexpected. Whether additional synergistic or antagonistic interactions among these G-protein receptor signaling pathways arise from simultaneous stimulation is not known. The signaling pathways affected by dual- and tri-agonism require more trenchant investigation before a comprehensive understanding of the cellular MOA. This knowledge will be essential for understanding the chronic efficacy and safety of these treatments.

Effect of Prolonged and Substantial Weight Loss on Incident Atrial Fibrillation: A Systematic Review and Meta-Analysis.

Background. Overweight and obesity are associated with atrial fibrillation (AF), and bariatric surgery (BS), able to induce sustained and prolonged weight loss, might represent the ideal treatment in the prevention of AF. Previous studies could not definitely establish a role for weight loss and BS in preventing incident AF so far. During the last few years, several studies on the effect of bariatric surgery on cardiovascular diseases have been published, and we performed a systematic review and meta-analysis to evaluate the role of weight loss through BS in the prevention of incident AF in obesity. Methods. This meta-analysis followed the PRISMA guideline. Eligible studies were controlled trials evaluating the appearance of atrial fibrillation in patients undergoing weight loss through BS as compared with patients receiving medical treatment. Quality of studies was assessed according to the Newcastle-Ottawa Quality Assessment Scale, and risk-of-bias was evaluated employing the Egger's test. All analyses were run by a random-effects model according to Hartung and Knapp and sensitivity analyses were performed. Heterogeneity was assessed through Q and I2 statistics for each comparison, and potential publication bias was formally investigated. Results. Ten studies were included in the meta-analysis, and the overall result was statistically significant [OR = 0.665 (0.475-0.929), p = 0.017], with significant heterogeneity (Q = 48.98, p < 0.001; I2 = 81.6%), but with no publication bias. In sensitivity analyses, the amount of weight loss, percentage of patients with diabetes and value of the Newcastle-Ottawa Quality Assessment Scale, were all associated with significance of effect. Since age was different in one study, a sensitivity analysis was performed by excluding this study; OR was similar [OR = 0.608 (0.454-0.814), p < 0.001]; heterogeneity was reduced but still significant (Q = 35.74, p < 0.001, I2 = 77.6%) and again no publication bias was detected. Conclusions. Bariatric surgery as compared to medical treatment is associated with reduced appearance of incident AF.

Immunogenicity and Safety of SARS-CoV-2 mRNA Vaccines in a Cohort of Patients With Type 1 Diabetes.

Patients with type 1 diabetes (T1D) may develop severe outcomes during coronavirus disease 2019 (COVID-19), but their ability to generate an immune response against the SARS-CoV-2 mRNA vaccines remains to be established. We evaluated the safety, immunogenicity, and glycometabolic effects of the severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) mRNA vaccines in patients with T1D. A total of 375 patients (326 with T1D and 49 subjects without diabetes) who received two doses of the SARS-CoV-2 mRNA vaccines (mRNA-1273, BNT162b2) between March and April 2021 at ASST Fatebenefratelli Sacco were included in this monocentric observational study. Local and systemic adverse events were reported in both groups after SARS-CoV-2 mRNA vaccination, without statistical differences between them. While both patients with T1D and subjects without diabetes exhibited a parallel increase in anti-SARS-CoV-2 spike titers after vaccination, the majority of patients with T1D (70% and 78%, respectively) did not show any increase in the SARS-CoV-2-specific cytotoxic response compared with the robust increase observed in all subjects without diabetes. A reduced secretion of the T-cell-related cytokines interleukin-2 and tumor necrosis factor-α in vaccinated patients with T1D was also observed. No glycometabolic alterations were evident in patients with T1D using continuous glucose monitoring during follow-up. Administration of the SARS-CoV-2 mRNA vaccine is associated with an impaired cellular SARS-CoV-2-specific cytotoxic immune response in patients with T1D.

Indirect and Direct Effects of SARS-CoV-2 on Human Pancreatic Islets.

Recent studies have shown that severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) infection may induce metabolic distress, leading to hyperglycemia in patients affected by coronavirus disease 19 (COVID-19). We investigated the potential indirect and direct effects of SARS-CoV-2 on human pancreatic islets in 10 patients who became hyperglycemic after COVID-19. Although there was no evidence of peripheral anti-islet autoimmunity, the serum of these patients displayed toxicity on human pancreatic islets, which could be abrogated by the use of anti-interleukin-1ß (IL-1ß), anti-IL-6, and anti-tumor necrosis factor α, cytokines known to be highly upregulated during COVID-19. Interestingly, the receptors of those aforementioned cytokines were highly expressed on human pancreatic islets. An increase in peripheral unmethylated INS DNA, a marker of cell death, was evident in several patients with COVID-19. Pathology of the pancreas from deceased hyperglycemic patients who had COVID-19 revealed mild lymphocytic infiltration of pancreatic islets and pancreatic lymph nodes. Moreover, SARS-CoV-2-specific viral RNA, along with the presence of several immature insulin granules or proinsulin, was detected in postmortem pancreatic tissues, suggestive of ß-cell-altered proinsulin processing, as well as ß-cell degeneration and hyperstimulation. These data demonstrate that SARS-CoV-2 may negatively affect human pancreatic islet function and survival by creating inflammatory conditions, possibly with a direct tropism, which may in turn lead to metabolic abnormalities observed in patients with COVID-19.

Biliopancreatic Diversion (BPD), Long Common Limb Revisional Biliopancreatic Diversion (BPD + LCL-R), Roux-en-Y Gastric Bypass [RYGB] and Sleeve Gastrectomy (SG) mediate differential quantitative changes in body weight and qualitative modifications in body composition: a 5-year study.

AIMS: Bariatric surgeries induce profound weight loss (decrease in body mass index, BMI), through a decrease in fat mass (FM) and to a much lesser degree of fat-free mass (FFM). Some reports indicate that the weight which is lost after gastric bypass (RYGB) and sleeve gastrectomy (SG) is at least partially regained 2 years after surgery. Here we compare changes in BMI and body composition induced by four bariatric procedures in a 5 years follow-up study. METHODS: We analyzed retrospectively modifications in BMI, FM and FFM obtained through Roux-en-Y gastric bypass (RYGB), sleeve gastrectomy (SG), biliopancreatic diversion (BPD) and a long common limb revisional biliopancreatic diversion (reduction of the gastric pouch and long common limb; BPD + LCL-R). Patients were evaluated at baseline and yearly for 5 years. Of the whole cohort of 565 patients, a subset of 180 patients had all yearly evaluations, while the remaining had incomplete evaluations. Setting University Hospital. RESULTS: In a total of 180 patients evaluated yearly for 5 years, decrease in BMI and FM up to 2 years was more rapid with RYGB and SG than BPD and BPD + LCL-R; with RYGB and SG both BMI and FM slightly increased in the years 3-5. At 5 years, the differences were not significant. When analysing the differences between 2 and 5 years, BPD + LCL-R showed a somewhat greater effect on BMI and FM than RYGB, BPD and SG. Superimposable results were obtained when the whole cohort of 565 patients with incomplete evaluation was considered. CONCLUSIONS: All surgeries were highly effective in reducing BMI and fat mass at around 2 years; with RYGB and SG both BMI and FM slightly increased in the years 3-5, while BPD and BPD + LCL-R showed a slight further decreases in the same time interval.

Physical activity as a proxy to ameliorate inflammation in patients with type 2 diabetes and periodontal disease at high cardiovascular risk.

While the beneficial impact of physical activity has been ascertained in a variety of pathological scenarios, including diabetes and low-grade systemic inflammation, its potential remains still putative for periodontal health. Periodontal disease has been associated with inflammatory systemic alterations, which share a common denominator with type 2 diabetes mellitus and cardiovascular disease. Physical exercise, along with nutritional counseling, is a cornerstone in the treatment and prevention of type 2 diabetes, also able to reduce the prevalence of periodontal disease and cardiovascular risk. In addition, considering the higher incidence of periodontitis in patients with type 2 diabetes compared to healthy controls, the fascinating research question would be whether physical activity could relieve the inflammatory pressure exerted by the combination of these two diseases. This multi-disciplinary viewpoint discusses available literature in order to argument the hypothesis of a "three-way relationship" linking diabetes, periodontitis, and physical activity.

High plasma renin activity associates with obesity-related diabetes and arterial hypertension, and predicts persistent hypertension after bariatric surgery.

BACKGROUND: Information about the renin-angiotensin-aldosterone system (RAAS) in obese individuals before and after bariatric surgery is scarce. Aim of this study was to analyze the RAAS in severely obese subjects, in relation to anthropometric and metabolic variables, with special reference to glucose tolerance. METHODS: 239 subjects were evaluated at baseline, and 181 one year after bariatric surgery [laparoscopic gastric banding (LAGB)]. RESULTS: At baseline, renin (plasma renin activity, PRA) was increased from normal to glucose tolerance and more in diabetes, also correlating with ferritin. After LAGB, the decrease of PRA and aldosterone was significant in hypertensive, but not in normotensive subjects, and correlatied with decrease of ferritin. PRA and glucose levels were predictive of persistent hypertension 1 year after LAGB. CONCLUSIONS: These data support the role of RAAS in the pathophysiology of glucose homeostasis, and in the regulation of blood pressure in obesity. Ferritin, as a proxy of subclinical inflammation, could be another factor contributing to the cross-talk between RAAS and glucose metabolism.

Pioglitazone corrects dysregulation of skeletal muscle mitochondrial proteins involved in ATP synthesis in type 2 diabetes.

CONTEXT: In this study, we aimed to identify the determinants of mitochondrial dysfunction in skeletal muscle (SKLM) of subjects with type 2 diabetes (T2DM), and to evaluate the effect of pioglitazone (PIO) on SKLM mitochondrial proteome. METHODS: Two different groups of adults were studied. Group I consisted of 8 individuals with normal glucose tolerance (NGT) and 8 with T2DM, subjected to SKLM mitochondrial proteome analysis by 2D-gel electrophoresis followed by mass spectrometry-based protein identification. Group II included 24 individuals with NGT and 24 with T2DM, whose SKLM biopsies were subjected to immunoblot analysis. Of the 24 subjects with T2DM, 20 were randomized to receive placebo or PIO (15 mg daily) for 6 months. After 6 months of treatment, SKLM biopsy was repeated. RESULTS: Mitochondrial proteomic analysis on Group I revealed that several mitochondrial proteins involved in oxidative metabolism were differentially expressed between T2DM and NGT groups, with a downregulation of ATP synthase alpha chain (ATP5A), electron transfer flavoprotein alpha-subunit (ETFA), cytochrome c oxidase subunit VIb isoform 1 (CX6B1), pyruvate dehydrogenase protein X component (ODPX), dihydrolipoamide dehydrogenase (DLDH), dihydrolipoamide-S-succinyltransferase (DLST), and mitofilin, and an up-regulation of hydroxyacyl-CoA-dehydrogenase (HCDH), 3,2-trans-enoyl-CoA-isomerase (D3D2) and delta3,5-delta2,4-dienoyl-CoA-isomerase (ECH1) in T2DM as compared to NGT subjects. By immunoblot analysis on SKLM lysates obtained from Group II we confirmed that, in comparison to NGT subjects, those with T2DM exhibited lower protein levels of ATP5A (-30%, P = 0.006), ETFA (-50%, P = 0.02), CX6B1 (-30%, P = 0.03), key factors for ATP biosynthesis, and of the structural protein mitofilin (-30%, P = 0.01). T2DM was associated with a reduced abundance of the enzymes involved in the Krebs cycle DLST and ODPX (-20%, P ≤ 0.05) and increased levels of HCDH and ECH1, enzymes implicated in the fatty acid catabolism (+30%, P ≤ 0.05). In subjects with type 2 diabetes treated with PIO for 6 months we found a restored SKLM protein abundance of ATP5A, ETFA, CX6B1, and mitofilin. Moreover, protein levels of HCDH and ECH1 were reduced by -10% and - 15% respectively (P ≤ 0.05 for both) after PIO treatment. CONCLUSION: Type 2 diabetes is associated with reduced levels of mitochondrial proteins involved in oxidative phosphorylation and an increased abundance of enzymes implicated in fatty acid catabolism in SKLM. PIO treatment is able to improve SKLM mitochondrial proteomic profile in subjects with T2DM.

Bariatric surgery, compared to medical treatment, reduces morbidity at all ages but does not reduce mortality in patients aged < 43 years, especially if diabetes mellitus is present: a post hoc analysis of two retrospective cohort studies.

BACKGROUND AND AIMS: Bariatric surgery (BS) reduces long-term mortality in comparison with medical treatment of obesity. Some studies indicate that this effect is significant for patients above mean age in different cohorts, but not for younger patients. These findings raise the question whether morbid obese patients should undergo BS as soon as possible, or whether patients might undergo surgery later in their life. METHODS: We performed a post hoc analysis of two studies; we evaluated surgery-related long-term mortality in: (1) the whole cohort [857 surgery patients (163 diabetes) vs. 2086 controls (512 diabetes)]; (2) patients above mean age [> 43 years, 427 surgery patients (133 diabetes) vs. 1054 controls (392 diabetes)]; (3) patients below mean age [≤ 43 years, 432 surgery patients (30 diabetes) vs. 1032 controls (120 diabetes]. Then, we analyzed age-related long-term mortality in the whole cohort, as well as in surgery patients and in controls. Finally, we analyzed incident diseases (diabetes, cardiovascular disease, and cancer) as a function of surgery versus no-surgery and of mean age. RESULTS: Surgery patients, compared with controls receiving standard medical/dietary treatment, had reduced mortality in the whole cohort (HR = 0.45, 95% CI 0.33-0.62, p = 0.001) and in the study group aged > 43 years (HR = 0.39, 95% CI 0.28-0.56, p = 0.001), but not in the study group aged ≤ 43 years (HR = 0.87, 95% CI 0.42-1.80, p = 0.711). Reduced mortality was observed in non-diabetic and diabetic patients aged > 43 years (HR = 0.37, 95% CI 0.23-0.62, p = 0.001 and HR = 0.45, 95% CI 0.27-0.74, p = 0.002, respectively) who underwent bariatric surgery. In contrast, in patients aged ≤ 43 years, no significant protective effect of bariatric surgery appeared in non-diabetic patients (HR = 0.64, 95% CI 0.24-1.71, p = 0.371), and mortality increased, almost significantly, in diabetic patients aged < 43 years (HR = 2.87, 95% CI 0.96-8.56, p = 0.058), and even more in diabetic patients aged 33-43 years; HR = 4.99, 95% CI 1.18-21.09, p = 0.029). As expected, age-related mortality was increased in the whole cohort (HR = 7.23, 95% CI 5.14-10.17, p = 0.001), in non-diabetic and diabetic controls (HR = 8.55, 95% CI 5.77-12.68, p = 0.001, and HR = 3.76, 95% CI 1.97-7.18, p = 0.001, respectively). The effect of aging was slightly reduced in surgery patients (HR = 3.76, 95% CI 1.87-7.58, p = 0.001), while it was not significant in diabetic surgery patients (HR = 0.70, 95% CI 0.26-1.90, p = 0.88), further emphasizing that diabetes per se has a strong negative effect on survival, also with concomitant bariatric surgery. In a supplementary analysis, HRs did not change when surgery and control parents were matched for the presence of diabetes. Incident diseases (cardiovascular, diabetes, and cancer) were less frequent in surgery than in control patients, irrespective of age. CONCLUSION: Bariatric surgery reduces long-term mortality in comparison with medical treatment when performed in patients aged > 43 years, but not in younger patients, where it is neutral or could even increase mortality; reduction in morbidity occurs at any age.

Incidence of Diabetes Mellitus, Cardiovascular Diseases, and Cancer in Patients Undergoing Malabsorptive Surgery (Biliopancreatic Diversion and Biliointestinal Bypass) vs Medical Treatment.

BACKGROUND AND AIMS: Bariatric surgeries such as gastric banding (LAGB), gastric bypass (RYGB), vertical banded gastroplasty (VBG), and sleeve gastrectomy (LSG) decrease body weight in morbid obesity, leading to the resolution of coexisting diabetes mellitus and arterial hypertension in the majority of cases as well as improvements of renal function and liver steatosis. BS (LAGB, RYGB, VBG, and LSG) also reduce incident cases of diabetes, of cardiovascular diseases, and of cancer; these therapeutic and preventive effects on comorbidities of obesity have not been analyzed for malabsorptive surgeries such as biliopancreatic diversion (BPD) or biliointestinal bypass (BIBP). The aim of this study was to analyze the incidence of comorbidities, i.e., diabetes, cardiovascular diseases, and cancer, in obese subjects undergoing BPD and BIBP, in comparison with standard medical treatment of obesity. PATIENTS AND METHODS: Medical records of 1983 obese patients (body mass index (BMI) > 35 kg/m2, aged 18-65 years, undergoing surgery (n = 472, of which 111 with diabetes) or medical treatment (n = 1511, of which 422 with diabetes), during the period 1999-2008 (visit 1)) were collected; incident cases of comorbidities were ascertained through December 31, 2016. RESULTS: Observation period was 12.0 ± 3.48 years (mean ± SD). Compared to non-surgical patients matched for age, body mass index, and blood pressure, malabsorptive surgeries were associated with reduced new incident cases of diabetes (p = 0.001), cardiovascular diseases (p = 0.001), hyperlipidemia (p = 0.001), oculopathy (p = 0.021), and cancer (p = 0.001). The preventive effect of BS was similar in both nondiabetic and diabetic patients for cardiovascular diseases and hyperlipidemia (both p = 0.001). The preventive effect was significant in nondiabetic subjects for coronary heart disease and for cancer, not significant in diabetic subjects. CONCLUSION: Patients undergoing malabsorptive bariatric surgery show less incident cases of diabetes, cardiovascular diseases, hyperlipidemia, oculopathy, and cancer than controls receiving medical treatment.

A 9 years comparison of weight loss, disappearance of obesity, and resolution of diabetes mellitus with biliointestinal bypass and with adjustable gastric banding: experience of a collaborative network.

AIMS: Long-term comparisons between bariatric surgical techniques have been performed for gastric bypass (RYGB), sleeve gastrectomy (LSG), and biliopancreatic diversion (BPD) vs gastric banding (LAGB), but short-term studies (6 months-4 years) have only compared biliointestinal bypass (BIBP) and LAGB. The participating institutions regularly perform both BIBP and LAGB with a common protocol, and the aim of this retrospective study was to compare long-term effects of the two procedures on body weight, on clinical and metabolic variables, and on resolution of obesity and of diabetes. METHODS: All procedures performed between 01/01/1998 and 31/12/2005 were considered; 73 out of 91 patients undergoing BIBP, and 154 out of 249 patients undergoing LAGB were evaluable up to 9 years. RESULTS: BIBP was significantly more effective than LAGB in terms of weight loss and of resolution of obesity (BMI < 30 kg/m2), in terms of decrease of systolic blood pressure and of serum cholesterol, and similar in terms of resolution of diabetes. In addition, the effect of BIBP was stable, while the effect of LAGB decreased with time. CONCLUSIONS: Both BIBP and LAGB exert long-term effects on body weight, on blood pressure, and on resolution of diabetes mellitus; the effect of BIBP is significantly greater than the effect of LAGB in terms of weight loss, resolution of obesity, of control of systolic blood pressure and of serum cholesterol, but not in terms of resolution of diabetes.

A 23-year study of mortality and development of co-morbidities in patients with obesity undergoing bariatric surgery (laparoscopic gastric banding) in comparison with medical treatment of obesity.

BACKGROUND AND AIM: Several studies have shown that bariatric surgery reduces long term mortality compared to medical weight loss therapy. In a previous study we have demonstrated that gastric banding (LAGB) is associated with reduced mortality in patients with and without diabetes, and with reduced incidence of obesity co-morbidities (cardiovascular disease, diabetes, and cancer) at a 17 year follow-up. The aim of this study was to verify at a longer time interval (23 years) mortality and incidence of co-morbidities in patients undergoing LAGB or medical weight loss therapy. PATIENTS AND METHODS: As reported in the previous shorter-time study, medical records of obese patients [body mass index (BMI) > 35 kg/m2 undergoing LAGB (n = 385; 52 with diabetes) or medical treatment (controls, n = 681; 127 with diabetes), during the period 1995-2001 (visit 1)] were collected. Patients were matched for age, sex, BMI, and blood pressure. Identification codes of patients were entered in the Italian National Health System Lumbardy database, that contains life status, causes of death, as well as exemptions, prescriptions, and hospital admissions (proxies of diseases) from visit 1 to June 2018. Survival was compared across LAGB patients and matched controls using Kaplan-Meier plots adjusted Cox regression analyses. RESULTS: Final observation period was 19.5 ± 1.87 years (13.4-23.5). Compared to controls, LAGB was associated with reduced mortality [HR = 0.52, 95% CI 0.33-0.80, p = 0.003], significant in patients with diabetes [HR = 0.46, 95% CI 0.22-0.94, p = 0.034], borderline significant in patients without diabetes [HR = 0.61, 95% CI = 0.35-1.05, p = 0.076]. LAGB was associated with lower incidence of diabetes (15 vs 75 cases, p = 0.001), of CV diseases (61 vs 226 cases, p = 0.009), of cancer (10 vs 35, p = 0.01), and of renal diseases (0 vs 35, p = 0.001), and of hospital admissions (92 vs 377, p = 0.001). CONCLUSION: The preventive effect of LAGB on mortality is maintained up to 23 years, even with a decreased efficacy compared with the shorter-time study, while the preventive effect of LAGB on co-morbidities and on hospital admissions increases with time.

Pancreatic islet of Langerhans' cytoarchitecture and ultrastructure in normal glucose tolerance and in type 2 diabetes mellitus.

While a number of structural and cellular abnormalities occur in the islet of Langerhans in diabetes, and in particular in type 2 diabetes, the focus has been mostly on the insulin producing ß-cells and only more recently on glucagon producing α- and δ-cells. There is ample evidence that in type 2 diabetes mellitus (T2DM), in addition to a progressive decline in ß-cell function and associated insulin resistance in a number of insulin-sensitive tissues, alterations in glucagon secretion are also present and may play an important role in the pathogenesis of hyperglycemia both in the fasting and in the postprandial state. Recently, a number of studies have showed that there are also functional and structural alterations in glucagon-producing α-cells and somatostatin-producing δ-cells. Thus, it is becoming increasingly clear that multiple cellular alterations of multiple cell types occur, which adds even more complexity to our understanding of the pathophysiology of this common and severe disease. We believe that persistent efforts to increase the understanding of the pathophysiology of hormone secretion in the islets of Langerhans will also improve our capability to better prevent and treat diabetes mellitus.

Islet-Derived eATP Fuels Autoreactive CD8+ T Cells and Facilitates the Onset of Type 1 Diabetes.

Extracellular ATP (eATP) activates T cells by engaging the P2X7R receptor. We identified two loss-of-function P2X7R mutations that are protective against type 1 diabetes (T1D) and thus hypothesized that eATP/P2X7R signaling may represent an early step in T1D onset. Specifically, we observed that in patients with newly diagnosed T1D, P2X7R is upregulated on CD8+ effector T cells in comparison with healthy control subjects. eATP is released at high levels by human/murine islets in vitro in high-glucose/inflammatory conditions, thus upregulating P2X7R on CD8+ T cells in vitro. P2X7R blockade with oxidized ATP reduces the CD8+ T cell-mediated autoimmune response in vitro and delays diabetes onset in NOD mice. Autoreactive CD8+ T-cell activation is highly dependent upon eATP/P2X7R-mediated priming, while a novel sP2X7R recombinant protein abrogates changes in metabolism and the autoimmune response associated with CD8+ T cells. eATP/P2X7R signaling facilitates the onset of autoimmune T1D by fueling autoreactive CD8+ cells and therefore represents a novel targeted therapeutic for the disorder.

Increased ß-Cell Workload Modulates Proinsulin-to-Insulin Ratio in Humans.

Increased proinsulin secretion, which characterizes type 2 diabetes and insulin resistance, may be due to an intrinsic, primitive defect in proinsulin processing or be secondary to increased demand on ß-cells (hyperinsulinemia secondary to insulin resistance). An alternative way to investigate the relation between relative hyperproinsulinemia and increased secretory demand is to study the dynamic changes in the proinsulin-to-insulin ratio after partial pancreatectomy, a model of acute increased ß-cell workload on the remaining pancreas. To pursue this aim, patients without diabetes, scheduled for partial pancreatectomy, underwent 4-h mixed-meal tests and hyperinsulinemic-euglycemic clamps before and after surgery. After acute ß-cell mass reduction, no changes were observed in the fasting proinsulin-to-insulin ratio, whereas the fold change in the proinsulin-to-insulin ratio significantly increased over time after the meal. Further, our data demonstrate that whole-body insulin resistance is associated with underlying defects in proinsulin secretion, which become detectable only in the presence of increased insulin secretion demand.