Effect of Prosopis ruscifolia on incretin and insulin secretion in alloxan-induced hyperglycemic rats / Efecto de Prosopis ruscifolia sobre la secreción de incretina e insulina de ratas hiperglicémicas por aloxano

Background: Diabetes mellitus treatment is based on oral hypoglycemic agents or insulin. Medicinal plants constitute an option, and the leaves of Prosopis ruscifolia (Pr) were shown to be effective in reducing glycemia in hyperglycemic animals. Objective: In this paper, we report the effect of P. rusciofolia (Pr) on insulin and incretin secretion in alloxan-induced hyperglycemic rats. Methodology: The effective dose was selected, and four groups (n=10) of Wistar rats were used. Two groups with normal glycemia received water or Pr (75 mg/Kg, per os, p.o.), and two groups with hyperglycemia induced by alloxan (intraperitoneal, ip), received water or Pr (75 mg/Kg, p.o.) for 2 weeks. Oral glucose tolerance test, and incretin and insulin levels were measured at the end of the experimental period. Results: The results showed that extract promotes better tolerance to oral glucose overload, in addition to a statistically significant (p<0.001) increase in blood levels of incretin and insulin, compared to the hyperglycemic rats. Conclusion: It is concluded that the ethanolic extract of P. ruscifolialeaves has a hypoglycemic effect in hyperglycemic animals by a mechanism that involves the incretin-insulin system

Antecedentes: la diabetes mellitus es una enfermedad metabólica cuyo tratamiento se basa en el uso de agentes hipoglicemiantes orales o insulina. Una opción al tratamiento son las plantas medicinales y en ese sentido, estudios previos en animales con hojas de Prosopis ruscifolia (Pr) han demostrado efecto hipoglicemiante. Objetivo: en este trabajo se reporta el efecto de P. rusciofolia (Pr) en la secreción de insulina e incretina, en ratas hiperglicémicas por aloxano. Metodología: se emplearon cuatro grupos de ratas Wistar (n=10). Dos grupos con glicemia normal que fueron tratadas con agua Pr (75 mg/Kg, per os, p.o.) y dos grupos con hiperglicemia inducida por la inyección intraperitoneal de aloxano recibieron agua Pr (75 mg/Kg, per os, p.o.) durante dos semanas. Se midieron la tolerancia oral a la glucosa, y los niveles de incretina e insulina al final del periodo de experimentación. Resultados: se encontró que el extracto promueve una mayor tolerancia a la sobrecarga de glucosa, y además un incremento significativo (p<0.001) de los niveles de incretina e insulina en sangre, comparados al grupo de ratas hiperglicémicas. Conclusión: se concluye que e l estracto etanólico de las hojas de P. ruscifolia tienen efecto hipoglicemiante en animales hiperglicémicos por un mecanismo que incluye al sistema incretina-insulina

Effect of free fatty acids on insulin secretion, insulin sensitivity and incretin effect - a narrative review

ABSTRACT Deleterious effects of free fatty acids, FFAs, on insulin sensitivity are observed in vivo studies in humans. Mechanisms include impaired insulin signaling, oxidative stress, inflammation, and mitochondrial dysfunction, but the effects on insulin secretion are less well known. Our aim was to review the relationship of increased FFAs with insulin resistance, secretion and mainly with the incretin effect in humans. Narrative review. Increased endogenous or administered FFAs induce insulin resistance. FFAs effects on insulin secretion are debatable; inhibition and stimulation have been reported, depending on the type and duration of lipids exposition and the study subjects. Chronically elevated FFAs seem to decrease insulin biosynthesis, glucose-stimulated insulin secretion and β-cell glucose sensitivity. Lipids infusion decreases the response to incretins with unchanged incretin levels in volunteers with normal glucose tolerance. In contrast, FFAs reduction by acipimox did not restore the incretin effect in type-2 diabetes, probably due to the dysfunctional β-cell. Possible mechanisms of FFAs excess on incretin effect include reduction of the expression and levels of GLP-1 (glucagon like peptide-1) receptor, reduction of connexin-36 expression thus the coordinated secretory activity in response to GLP-1, and GIP (glucose-dependent insulinotropic polypeptide) receptors downregulation in islets cells. Increased circulating FFAs impair insulin sensitivity. Effects on insulin secretion are complex and controversial. Deleterious effects on the incretin-induced potentiation of insulin secretion were reported. More investigation is needed to better understand the extent and mechanisms of β-cell impairment and insulin resistance induced by increased FFAs and how to prevent them.

Changes in Glucose Metabolism with Aging / 임상당뇨병

The increasing risk of glucose intolerance and diabetes associated with aging is well established. However, it is difficult to determine whether changes in glucose metabolism result from biological aging itself or due to various environmental factors that occur during the aging process. Many epidemiologic studies have shown that plasma glucose levels after oral glucose tolerance test rise consecutively for every decade of age, but many of these studies also demonstrated the effects of environmental factors including obesity and exercise. In some studies, the development of insulin resistance and insulin secretion defects due to biological aging itself have also been identified as major etiologic factors of glucose intolerance. However, the rate of diabetes development due to these factors is expected to be very slow and largely preventable by addressing environmental risk factors.

Asian Subpopulations May Exhibit Greater Cardiovascular Benefit from Long-Acting Glucagon-Like Peptide 1 Receptor Agonists: A Meta-Analysis of Cardiovascular Outcome Trials

BACKGROUND: Based on reported results of three large cardiovascular outcome trials (CVOTs) of glucagon-like peptide 1 receptor agonists (GLP-1 RAs), we aimed to investigate the overall effect of GLP-1 RAs on major adverse cardiovascular events (MACEs) and to identify subpopulations exhibiting the greatest cardiovascular (CV) benefit. METHODS: Three CVOTs reporting effects of long-acting GLP-1 RAs were included: LEADER (liraglutide), SUSTAIN-6 (semaglutide), and EXSCEL (exenatide once weekly). In all studies, the primary endpoint was three-point MACE, comprising CV death, non-fatal myocardial infarction, and non-fatal stroke. Overall effect estimates were calculated as hazard ratios and 95% confidence intervals (CIs) using the random-effects model; subgroup analyses reported in the original studies were similarly analyzed. RESULTS: Overall, statistically significant risk reductions in MACE and CV death were observed. Subgroup analysis indicated a significant racial difference with respect to CV benefit (P for interaction <0.001), and more substantial risk reductions were observed in subjects of African origin (relative risk [RR], 0.78; 95% CI, 0.60 to 0.99) and in Asians (RR, 0.35; 95% CI, 0.09 to 1.32). However, post hoc analysis (Bonferroni method) revealed that only Asians exhibited a significantly greater CV benefit from treatment, compared with white subjects (P<0.0001). CONCLUSION: Long-acting GLP-1 RAs reduced risks of MACE and CV deaths in high-risk patients with type 2 diabetes mellitus. Our findings of a particularly effective reduction in CV events with GLP-1 RA in Asian populations merits further exploration and dedicated trials in specific populations.

Additional Effect of Dietary Fiber in Patients with Type 2 Diabetes Mellitus Using Metformin and Sulfonylurea: An Open-Label, Pilot Trial

BACKGROUND: Metformin, sulfonylurea, and dietary fiber are known to affect gut microbiota in patients with type 2 diabetes mellitus (T2DM). This open and single-arm pilot trial investigated the effects of the additional use of fiber on glycemic parameters, insulin, incretins, and microbiota in patients with T2DM who had been treated with metformin and sulfonylurea. METHODS: Participants took fiber for 4 weeks and stopped for the next 4 weeks. Glycemic parameters, insulin, incretins during mixed-meal tolerance test (MMTT), lipopolysaccharide (LPS) level, and fecal microbiota were analyzed at weeks 0, 4, and 8. The first tertile of difference in glucose area under the curve during MMTT between weeks 0 and 4 was defined as ‘responders’ and the third as ‘nonresponders,’ respectively. RESULTS: In all 10 participants, the peak incretin levels during MMTT were higher and LPS were lower at week 4 as compared with at baseline. While the insulin sensitivity of the ‘responders’ increased at week 4, that of the ‘nonresponders’ showed opposite results. However, the results were not statistically significant. In all participants, metabolically unfavorable microbiota decreased at week 4 and were restored at week 8. At baseline, metabolically hostile bacteria were more abundant in the ‘nonresponders.’ In ‘responders,’ Roseburia intestinalis increased at week 4. CONCLUSION: While dietary fiber did not induce additional changes in glycemic parameters, it showed a trend of improvement in insulin sensitivity in ‘responders.’ Even if patients are already receiving diabetes treatment, the additional administration of fiber can lead to additional benefits in the treatment of diabetes.

Factors Related to Blood Intact Incretin Levels in Patients with Type 2 Diabetes Mellitus

BACKGROUND: We performed this study to identify factors related to intact incretin levels in patients with type 2 diabetes mellitus (T2DM). METHODS: We cross-sectionally analyzed 336 patients with T2DM. Intact glucagon-like peptide 1 (iGLP-1) and intact glucose-dependent insulinotropic polypeptide (iGIP) levels were measured in a fasted state and 30 minutes after ingestion of a standard mixed meal. The differences between 30 and 0 minute iGLP-1 and iGIP levels were indicated as ΔiGLP-1 and ΔiGIP. RESULTS: In simple correlation analyses, fasting iGLP-1 was positively correlated with glucose, C-peptide, creatinine, and triglyceride levels, and negatively correlated with estimated glomerular filtration rate. ΔiGLP-1 was positively correlated only with ΔC-peptide levels. Fasting iGIP showed positive correlations with glycosylated hemoglobin (HbA1c) and fasting glucose levels, and negative correlations with ΔC-peptide levels. ΔiGIP was negatively correlated with diabetes duration and HbA1c levels, and positively correlated with Δglucose and ΔC-peptide levels. In multivariate analyses adjusting for age, sex, and covariates, fasting iGLP-1 levels were significantly related to fasting glucose levels, ΔiGLP-1 levels were positively related to ΔC-peptide levels, fasting iGIP levels were related to fasting C-peptide levels, and ΔiGIP levels were positively related to ΔC-peptide and Δglucose levels. CONCLUSION: Taken together, intact incretin levels are primarily related to C-peptide and glucose levels. This result suggests that glycemia and insulin secretion are the main factors associated with intact incretin levels in T2DM patients.

Diabetes and bone

Bone disease is a serious complication to diabetes. Patients with type 1 diabetes (T1D) and type 2 diabetes (T2D) suffer from an increased risk of fracture, most notably at the hip, compared with patients without diabetes. Confounders such as patient sex, age, body mass index, blood glucose status, fall risk, and diabetes medications may influence the fracture risk. Different underlying mechanisms contribute to bone disease in patients with diabetes. Bone quality is affected by low bone turnover in T1D and T2D, and furthermore, incorporation of advanced glycation end-products, changes in the incretin hormone response, and microvascular complications contribute to impaired bone quality and increased fracture risk. Diagnosis of bone disease in patients with diabetes is a challenge as current methods for fracture prediction such as bone mineral density T-score and fracture risk assessment tools underestimate fracture risk for patients with T1D and T2D. This review focuses on bone disease and fracture risk in patients with diabetes regarding epidemiology, underlying disease mechanisms, and diagnostic methods, and we also provide considerations regarding the management of diabetes patients with bone disease in terms of an intervention threshold and different treatments.

Bipartición de tránsito intestinal, la nueva era de la cirugía metabólica para la diabetes mellitus de tipo 2 / Intestinal transit bipartition, the new era in metabolic surgery for type 2 diabetes

Antecedentes. La diabetes mellitus de tipo 2 es el principal reto de salud pública que enfrentamos actualmente, constituye la primera causa de discapacidad y es o está asociada a las principales causas de muerte en nuestro país. En Ciudad de México, se reportó que más del 79 % de los pacientes diabéticos no tienen cifras óptimas de HbA1c (<6,5 %), mientras que el 47 % presentan descontrol importante (HbA1c >9 %). La cirugía metabólica es el mejor tratamiento en términos de remisión, sin embargo, los mecanismos involucrados no son los tradicionalmente considerados. Objetivo. Ofrecer actualización acerca de los mecanismos involucrados en la remisión de la diabetes mellitus de tipo 2 después de la cirugía metabólica. Metodos. Se hizo una revisión bibliográfica utilizando las palabras clave en términos MeSH; hasta el 1° de junio del 2018, se encontraron 83 artículos de referencia considerados como pertinentes. Resultados. La remisión de la diabetes mellitus de tipo 2 lograda por procedimientos quirúrgicos, depende de complejas interacciones entre la microbiota, los ácidos biliares y el epitelio intestinal, más que de procesos malabsortivos o restrictivos. La bipartición de tránsito intestinal es una opción quirúrgica basada en los principios fisiológicos responsables en la remisión de la diabetes, y es la más sencilla y segura para el manejo de la diabetes mellitus. Conclusiones. La cirugía metabólica ofrece mejores tasas de remisión y control de complicaciones de la diabetes tipo 2 al modificar la secreción de enterohormonas, la concentración e interacciones de los ácidos biliares y al modificar la microbiota

Background: Diabetes mellitus type 2 (DM2) is a major public health challenge that we face today; it is the first cause of disability and is associated with the main causes of death in our country. In Mexico City, it was reported that more than 79% of diabetic patients did not have optimal levels of HbA1c (<6.5%), while 47% are not properly controlled (HbA1c> 9%). Metabolic surgery is the best treatment option for DM2, yet the presumed involved mechanisms are not traditionally considered. Objective: To provide an update on the mechanisms involved in the remission of DM2 following metabolic surgery. Methods: Narrative review of the literature, using MeSH terms, until June 1, 2018, encountering 83 articles considered pertinent. Methods: Narrative review of the literature, using MeSH terms, until June 1, 2018, encountering 83 articles considered pertinent. Results: DM2 remission after surgery depends on complex interactions between the microbiota, biliary acids and the intestinal epithelium, more so than of malabsortion or restrictive processes. Bipartition of the intestinal transit constitutes a surgical option based on the physiologic principles responsible of the remission of diabetes, and it is a simple and most secure procedure for the management of diabetes. Mechanisms include restoration/ enhancement of incretin secretion; as well as an improvement of bile acid concentration and microbiome manipulation, rather than the commonly accepted restriction and malabsorption. Intestinal transit bipartition is a novel and simple procedure that complies with the actual involved mechanisms, with comparable results in terms of safety and efficacy with the more complex and demanding techniques, such as the gastric bypass. Conclusions: Metabolic surgery is the best treatment for DM2 in terms of remission and prevention of complications, modifying the secretion of enterohormones, the concentration of biliary acids, and the modification of the microbiota

Skeletal Fragility in Type 2 Diabetes Mellitus

Type 2 diabetes (T2D) is associated with an increased risk of fracture, which has been reported in several epidemiological studies. However, bone mineral density in T2D is increased and underestimates the fracture risk. Common risk factors for fracture do not fully explain the increased fracture risk observed in patients with T2D. We propose that the pathogenesis of increased fracture risk in T2D is due to low bone turnover caused by osteocyte dysfunction resulting in bone microcracks and fractures. Increased levels of sclerostin may mediate the low bone turnover and may be a novel marker of increased fracture risk, although further research is needed. An impaired incretin response in T2D may also affect bone turnover. Accumulation of advanced glycosylation endproducts may also impair bone strength. Concerning antidiabetic medication, the glitazones are detrimental to bone health and associated with increased fracture risk, and the sulphonylureas may increase fracture risk by causing hypoglycemia. So far, the results on the effect of other antidiabetics are ambiguous. No specific guideline for the management of bone disease in T2D is available and current evidence on the effects of antiosteoporotic medication in T2D is sparse. The aim of this review is to collate current evidence of the pathogenesis, detection and treatment of diabetic bone disease.

Cardiovascular Outcome Trials of Incretin Therapy (Dipeptidyl Peptidase-4 Inhibitors/Glucagon-Like Peptide-1 Receptor Agonist)

In 2008, the United States Food and Drug Administration issued guidance which mandated long-term cardiovascular outcome trials (CVOTs) to assess the safety of new antidiabetic drugs for type 2 diabetes. Since 2008, three CVOTs that have studied dipeptidyl peptidase-4 (DPP-4) inhibitors and four CVOTs of a glucagon-like peptide-1 (GLP-1) receptor agonist (GLP-1RA) have been reported. Each of the completed CVOTs showed the noninferiority of respective drugs to placebo for primary CV composite endpoint. Among them, liraglutide and semaglutide showed a reduction of major adverse cardiovascular events. However, the mechanisms for the observed cardiovascular differences between DPP-4 inhibitors and GLP-1RA, and across individual GLP-1RA are not clearly understood. Therefore, this review will summarize the CVOTs of the DPP-4 inhibitors and GLP-1RA, interpretation of cardioprotective results of incretin-based therapy and the possible mechanism of action.

Effect of Nutrient Preload and Food Order on Glucose, Insulin, and Gut Hormones / 임상당뇨병

Postprandial hyperglycemia is associated with the risk of diabetes mellitus, cardiovascular disease, and mortality. Nutrition therapy is an important component of the management of postprandial hyperglycemia. Postprandial glucose levels are determined by several factors, such as the quantity and composition of nutrients, gastric emptying rates, secretion of incretin hormones, insulin secretion, glucose uptake by peripheral tissues, and endogenous glucose production. Nutrient preload and food order (or meal sequence) are dietary approaches targeting these factors. Nutrient preload reduces postprandial glucose excursion by enhancing insulin secretion, augmenting the secretion of glucagonlike peptide-1, and delaying gastric emptying. Carbohydrates-last food order improves glycemic control, increases the secretion of glucagon-like peptide-1, and decreases insulin requirements. Therefore, both nutrient preload and manipulation of food order can be an effective, safe, and feasible strategy for treating hyperglycemia in individuals with diabetes mellitus.

Glucose-Lowering Agents in the Management of Nonalcoholic Fatty Liver Disease / 임상당뇨병

Nonalcoholic fatty liver disease (NAFLD) is more prevalent in diabetic patients than in non-diabetic subjects, because the two diseases share a common pathophysiological mechanism. Associated abnormalities can be observed from the pre-diabetic stage. Lifestyle intervention, including diet, exercise, and weight loss, is the primary recommended therapy for NAFLD. Among the therapeutic drugs for NAFLD treatment, anti-diabetic agents are aimed at improving or slowing the progression of NAFLD in addition to lowering blood glucose. In this paper, we systemically review the evidence surrounding antidiabetic medications and their ability to improve disease progression in patients with NAFLD.

Potentiation of endothelium-dependent vasorelaxation of mesenteric arteries from spontaneously hypertensive rats by gemigliptin, a dipeptidyl peptidase-4 inhibitor class of anti-diabetic drug

Dipeptidyl peptidase4 (DPP4) inhibitors such as gemigliptin are anti-diabetic drugs elevating plasma concentration of incretins such as GLP-1. In addition to the DPP4 inhibition, gemigliptin might directly improve the functions of vessels under pathological conditions. To test this hypothesis, we investigated whether the acetylcholine-induced endothelium dependent relaxation (ACh-EDR) of mesenteric arteries (MA) are altered by gemigliptin pretreatment in Spontaneous Hypertensive Rats (SHR) and in Wistar-Kyoto rats (WKY) under hyperglycemia-like conditions (HG; 2 hr incubation with 50 mM glucose). ACh-EDR of WKY was reduced by the HG condition, which was significantly recovered by 1 µM gemigliptin while not by saxagliptin and sitagliptin up to 10 µM. The ACh-EDR of SHR MA was also improved by 1 µM gemigliptin while similar recovery was observed with higher concentration (10 µM) of saxagliptin and sitagliptin. The facilitation of ACh-EDR by gemigliptin in SHR was not observed under pretreatment with NOS inhibitor, L-NAME. In the endotheliumdenuded MA of SHR, sodium nitroprusside induced dose-dependent relaxation was not affected by gemigliptin. The ACh-EDR in WKY was decreased by treatment with 30 µM pyrogallol, a superoxide generator, which was not prevented by gemigliptin. Exendin-4, a GLP-1 analogue, could not enhance the ACh-EDR in SHR MA. The present results of ex vivo study suggest that gemigliptin enhances the NOS-mediated EDR of the HG-treated MA as well as the MA from SHR via GLP-1 receptor independent mechanism.

New therapeutic agents in diabetic nephropathy

Studies investigating diabetic nephropathy (DN) have mostly focused on interpreting the pathologic molecular mechanisms of DN, which may provide valuable tools for early diagnosis and prevention of disease onset and progression. Currently, there are few therapeutic drugs for DN, which mainly consist of antihypertensive and antiproteinuric measures that arise from strict renin-angiotensin-aldosterone system inactivation. However, these traditional therapies are suboptimal and there is a clear, unmet need for treatments that offer effective schemes beyond glucose control. The complexity and heterogeneity of the DN entity, along with ambiguous renal endpoints that may deter accurate appraisal of new drug potency, contribute to a worsening of the situation. To address these issues, current research into original therapies to treat DN is focusing on the intrinsic renal pathways that intervene with intracellular signaling of anti-inflammatory, antifibrotic, and metabolic pathways. Mounting evidence in support of the favorable metabolic effects of these novel agents with respect to the renal aspects of DN supports the likelihood of systemic beneficial effects as well. Thus, when translated into clinical use, these novel agents would also address the comorbid factors associated with diabetes, such as obesity and risk of cardiovascular disease. This review will provide a discussion of the promising and effective therapeutic agents for the management of DN.

Inhibidores de la dipeptidil peptidasa 4 y una nueva estrategia farmacológica en la diabetes mellitus tipo 2 / Inhibitors of dipeptidil peptidase 4 new pharmacologic strategic in the diabetes mellitus type 2

La diabetes mellitus sigue siendo una enfermedad temible. El uso adecuado de la farmacoterapia para el control metabólico, ayudaría a disminuir la incidencia de complicaciones. Actualmente se dispone de variados grupos farmacológicos para el control temporal de las cifras de glucemias de pacientes con diabetes mellitus tipo 2, entre ellos están los inhibidores de la dipeptidil peptidasa 4 caracterizados por estimular el aumento de la concentración del péptido similar a glucagón tipo 1 GLP-1 y la secreción de insulina en la célula beta del islote pancreático. La eficacia, en términos de hemoglobina glucosilada, ha mostrado ser inferior a la de la insulina, pero sin el potencial del peligro de hipoglucemia, así como el efecto neutro o la disminución del peso corporal. Se realizó esta revisión bibliográfica con el objetivo de actualizar los conocimientos sobre el papel de las sustancias con acción incretinas en el control metabólico de los pacientes con diabetes mellitus tipo 2 y específicamente la acción de los IDPP4, ya que es creciente el problema de dicha enfermedad y se requiere, cada vez más, una mejor información de los fármacos a utilizar, aunque en el futuro los datos obtenidos concluirán su efectividad(AU)

Diabetes mellitus remains a fearsome disease. Proper use of pharmacotherapy for metabolic control, would help reduce the incidence of complications. Currently there are various pharmacological groups for temporary control of blood glycemia of patients with diabetes mellitus type 2. One of them is dipeptidyl peptidase-4 inhibitor characterized by stimulating increased concentration like peptide glucagon type 1 GLP -1 and insulin secretion in pancreatic islet beta cell. The effectiveness in terms of glycosylated hemoglobin has shown to be less than that of insulin, but without the potential danger of hypoglycaemia and the neutral effect or decrease in body weight. These facts prompt this literature review which was conducted to update the knowledge on the role of substances with incretin action in the metabolic control of patients with diabetes mellitus type 2, specifically the action of IDPP4, as this disease is an growing problem requiring better information on drug use(AU)

Efeito da cirurgia bariátrica sobre parâmetros clínicos, laboratoriais e fatores de risco cardiovascular / Effect of bariatric surgery on clinical, laboratory and cardiovascular risk factors

Introdução - Na prevenção primária das doenças cardiovasculares, a adoção de estilo de vida saudável representa uma das estratégias mais importantes. Entretanto, baixos índices de adesão e o abandono da dieta constituem obstáculo importante ao tratamento. Neste sentido, as intervenções cirúrgicas surgiram como um mecanismo promotor da restrição alimentar e têm ganhado importância não só pelo tratamento da obesidade como também no controle dos fatores de risco cardiovascular e na possível redução da mortalidade. Através de estudos clínicos foi possível observar que estas estratégias cirúrgicas promovem profundas modificações estruturais no trato gastrointestinal gerando aumento da saciedade e da sensibilidade à insulina. Em especial para os pacientes diabéticos, por si só associados a maior risco cardiovascular, as cirurgias bariátricas seriam capazes de promover um efeito muito intenso e agudo sobre os marcadores relacionados ao desenvolvimento da aterosclerose. Um evento muito definido no tempo como uma intervenção cirúrgica pode ser muito útil para o estudo e identificação de mecanismos que ainda não estão completamente estabelecidos no processo aterosclerótico. Objetivos - Analisar o comportamento das variáveis laboratoriais, clínicas e estruturais relacionadas ao desenvolvimento e progressão da aterosclerose em indivíduos diabéticos submetidos à cirurgia bariátrica. Métodos - Foram incluídos vinte voluntários diabéticos refratários ao tratamento clínico e que apresentavam obesidade abdominal. Deste grupo, metade foi aleatoriamente selecionada para realização da cirurgia bariátrica e metade foi mantida em tratamento clínico otimizado. Todos os participantes foram submetidos a exames clínicos e bioquímicos nas mesmas ocasiões, até trinta dias antes da cirurgia, três e vinte e quatro meses após a cirurgia. Nestas ocasiões além do perfil lipídico e da glicemia, determinamos os hormônios incretínicos, adipocinas. A avaliação da quantidade de gordura epicárdica...

Introduction - The adoption of a healthy lifestyle is one of the most important strategies for the primary prevention of cardiovascular diseases. However, low adhesion rates constitute a major obstacle to treatment. In this scenario, bariatric surgery emerged as an interesting option to promote dietary restriction and have gained importance, not only as obesity treatment but also in the control of cardiovascular risk factors and possible mortality reduction. Data from literature has shown that the surgical strategies can promote deep structural modifications in gastrointestinal tract leading to increased satiety and insulin sensitivity. In diabetic patients, already associated with a higher cardiovascular risk, the surgery would be able to promote a very intense and acute effect on the markers related to the development of atherosclerosis. This procedure, such as a very definite event in time, can be very useful for the study and identification of mechanisms that are not fully established in the atherosclerotic process. Aim - To analyse laboratory, clinical and structural variables related to the development and progression of atherosclerosis in diabetic patients undergoing bariatric surgery. Methods - Twenty diabetic individuals with a BMI between 28-35kg/m2 were randomized to bariatric surgery or clinical treatment and ten healthy subjects (normal BMI) represented the control group. All participants underwent clinical and biochemical tests on the same occasions , up to thirty days before the surgery, three and twenty-four months after surgery. On these occasions beyond the lipid profile and glucose, we determine the incretin hormones, adipokines. Evaluation of the amount of epicardial fat and the presence of hepatic steatosis will be performed only after two years, in conjunction of the other variables. Results - In the baseline surgical group differ from clinical group showing a higher BMI, Glycaemia and Triglycerides. For this...

In Vivo Models for Incretin Research: From the Intestine to the Whole Body

Incretin hormones are produced by enteroendocrine cells (EECs) in the intestine in response to ingested nutrient stimuli. The incretin effect is defined as the difference in the insulin secretory response between the oral glucose tolerance test and an isoglycemic intravenous glucose infusion study. The pathophysiology of the decreased incretin effect has been studied as decreased incretin sensitivity and/or β-cell dysfunction per se. Interestingly, robust increases in endogenous incretin secretion have been observed in many types of metabolic/bariatric surgery. Therefore, metabolic/bariatric surgery has been extensively studied for incretin physiology, not only the hormones themselves but also alterations in EECs distribution and genetic expression levels of gut hormones. These efforts have given us an enormous understanding of incretin biology from synthesis to in vivo behavior. Further innovative studies are needed to determine the mechanisms and targets of incretin hormones.

Novel Molecules Regulating Energy Homeostasis: Physiology and Regulation by Macronutrient Intake and Weight Loss

Excess energy intake, without a compensatory increase of energy expenditure, leads to obesity. Several molecules are involved in energy homeostasis regulation and new ones are being discovered constantly. Appetite regulating hormones such as ghrelin, peptide tyrosine-tyrosine and amylin or incretins such as the gastric inhibitory polypeptide have been studied extensively while other molecules such as fibroblast growth factor 21, chemerin, irisin, secreted frizzle-related protein-4, total bile acids, and heme oxygenase-1 have been linked to energy homeostasis regulation more recently and the specific role of each one of them has not been fully elucidated. This mini review focuses on the above mentioned molecules and discusses them in relation to their regulation by the macronutrient composition of the diet as well as diet-induced weight loss.

An Update on the Effect of Incretin-Based Therapies on β-Cell Function and Mass

Type 2 diabetes mellitus (T2DM) is a multifactorial disease with a complex and progressive pathogenesis. The two primary mechanisms of T2DM pathogenesis are pancreatic β-cell dysfunction and insulin resistance. Pancreatic β-cell dysfunction is recognized to be a prerequisite for the development of T2DM. Therapeutic modalities that improve β-cell function are considered critical to T2DM management; however, blood glucose control remains a challenge for many patients due to suboptimal treatment efficacy and the progressive nature of T2DM. Incretin-based therapies are now the most frequently prescribed antidiabetic drugs in Korea. Incretin-based therapies are a favorable class of drugs due to their ability to reduce blood glucose by targeting the incretin hormone system and, most notably, their potential to improve pancreatic β-cell function. This review outlines the current understanding of the incretin hormone system in T2DM and summarizes recent updates on the effect of incretin-based therapies on β-cell function and β-cell mass in animals and humans.