Effects of saxagliptin added to sub-maximal doses of metformin compared with uptitration of metformin in type 2 diabetes: the PROMPT study

Abstract

Objective:

The PROMPT study compared efficacy and tolerability of two treatment intensification strategies: adding saxagliptin or uptitrating metformin monotherapy, in patients with type 2 diabetes (T2D) and inadequate glycaemic control on a sub-maximal metformin dose.     

Sitagliptin added to treatment with ongoing pioglitazone for up to 52 weeks improves glycemic control in Japanese patients with type 2 diabetes

Aims/Introduction:  Patients with type 2 diabetes mellitus often require treatment with more than one oral antihyperglycemic agent to achieve their glycemic goal. The present study was carried out to assess the efficacy and safety of sitagliptin as add‐on therapy in Japanese patients with type 2 diabetes mellitus inadequately controlled (HbA1c ≥ 6.9% and <10.4%) on pioglitazone monotherapy (15–45 mg/day).Materials and Methods:  In the initial 12‐week, double‐blind treatment period, patients were randomized (1:1) to sitagliptin 50 mg/day (n = 66) or placebo (n = 68), followed by a 40‐week open‐label treatment period in which all patients received sitagliptin 50 mg/day that could have been increased to 100 mg/day for patients meeting predefined glycemic parameters.Results:  After 12 weeks, mean changes from baseline in HbA1c (the primary end‐point), fasting plasma glucose and 2‐h post‐meal glucose were −0.8%, −0.9 mmol/L and −2.7 mmol/L, respectively, in the sitagliptin group compared with placebo (all P < 0.001). The incidence of adverse experiences during the double‐blind treatment period was similar in both treatment groups, and the incidences of hypoglycemia and gastrointestinal adverse experiences were low. In the open‐label period, improvements in glycemic parameters with sitagliptin treatment were maintained and sitagliptin was generally well tolerated.Conclusions:  Sitagliptin as add‐on therapy provided significant improvements in glycemic parameters and was well tolerated in Japanese patients with type 2 diabetes mellitus inadequately controlled on pioglitazone monotherapy. This trial was registered with ClinicalTrials.gov (no. {"type":"clinical-trial","attrs":{"text":"NCT00372060","term_id":"NCT00372060"}}NCT00372060). (J Diabetes Invest, doi: 10.1111/j.2040‐1124.2011.00120.x, 2011)     

The novel GLP-1/GIP dual agonist DA3-CH is more effective than liraglutide in reducing endoplasmic reticulum stress in diabetic rats with cerebral ischemia-reperfusion injury

Background and aimsDiabetes is one of the most important risk factors and comorbidities of ischemic stroke. Endoplasmic reticulum stress (ERS) is considered to be the major injury mechanism of ischemic stroke with diabetes. Studies have found that incretin can inhibit ERS in ischemia-reperfusion injury of the liver and heart. We aimed to explore the effects of GLP-1/GIP double agonist DA3-CH and GLP-1 single agonist liraglutide on ERS and apoptosis in diabetic rats with cerebral ischemia-reperfusion injury.Methods and results72 Sprague–Dawley (SD) male rats were randomly divided into 4 groups: ① blank group (Sham group, n = 18); model group (Saline group, n = 18); DA3 treatment group (DA3 group, n = 18); liraglutide treatment group (Lir group, n = 18). The Sham group was not given any treatment and was only raised in the same environment as the other groups. The remaining 3 groups used STZ-induced diabetes models. After the successful membrane formation of diabetes, DA3-CH and liraglutide (10 mmol/kg, once-daily for 14 days) were injected intraperitoneally. Thereafter, rats were subjected to middle cerebral artery occlusion followed by 24-h reperfusion. Animals were evaluated for neurologic deficit score, infarct volume, and biomarker analyses of the brain after ischemia. The DA3-CH-treated and liraglutide-treated groups showed significantly reduced scores of neurological dysfunction and cerebral infarction size, and reduced the expression of ERS markers GRP78, CHOP and Caspase-12, and the expression of apoptosis marker bax. Anti-apoptotic markers bcl-2 and neuronal numbers increased significantly.ConclusionsDA3-CH and liraglutide have obvious neuroprotective effects in a rat model of cerebral ischemia-reperfusion injury with diabetes, which can reduce the infarct size and the neurological deficit score. Their exert neuroprotective effects in a rat model of cerebral ischemia-reperfusion injury with diabetes by inhibiting endoplasmic reticulum stress and thereby reducing apoptosis. DA3 is better than liraglutide.     

Gastrointestinal peptides controlling body weight homeostasis

Obesity has become an international public health problem. Unfortunately, effective treatment options are limited. In the last 20 years, research in obesity and associated pathologies has derived in a significant increase in the knowledge of the physiological and molecular mechanism regulating body mass, such as gastrointestinal-neuroendocrine communications. Gut-brain peptides may provide attractive therapeutic targets against this disease. This review summarizes research into energy balance through gastrointestinal tract peptides. Understanding these molecular mechanisms will provide new pharmacological targets for the treatment of obesity and appetite disorders.     

GLP-1受体激动剂与二肽基肽酶4抑制剂治疗2型糖尿病的比较

随着对肠促胰素在维持葡萄糖稳定作用认识的日益增多,促进了针对2型糖尿病患者肠促胰素活性缺乏治疗药物的研发.根据肠促胰素治疗药物不同的作用机制,可分为以下2类:(1)胰升糖素样肽1(GLP-1)受体激动剂,包括利拉鲁肽(liraglutide)、艾塞那肽每日2次制剂和艾塞那肽每周1次制剂;(2)二肽基肽酶4(DPP-4)抑制剂,包括西格列汀(sitagliptin)、利拉利汀(linagliptin)、沙格列汀(saxagliptin)和维格列汀(vildagliptin),DPP-4抑制剂可限制内源性GLP-1的降解.这2类药物具有某些共性,如葡萄糖依赖性刺激胰岛素分泌,低血糖发生率低.然而这2类药物在疗效方面的表现却有所不同.本文综述了这2类基于肠促胰素治疗药物的药代动力学及其临床方面的疗效和安全性,阐明了此类药物在2型糖尿病治疗中的地位.     

High protein diet leads to prediabetes remission and positive changes in incretins and cardiovascular risk factors

Background and aimsHigh Protein diets may be associated with endocrine responses that favor improved metabolic outcomes. We studied the response to High Protein (HP) versus High Carbohydrate (HC) Diets in terms of incretin hormones GLP-1 and GIP, the hunger hormone ghrelin and BNP, which is associated with cardiac function. We hypothesized that HP diets induce more pronounced release of glucose lowering hormones, suppress hunger and improve cardiac function.Methods and results24 obese women and men with prediabetes were recruited and randomized to either a High Protein (HP) (n = 12) or High Carbohydrate (HC) (n = 12) diet for 6 months with all food provided. OGTT and MTT were performed and GLP-1, GIP, Ghrelin, BNP, insulin and glucose were measured at baseline and 6 months on the respective diets.Our studies showed that subjects on the HP diet had 100% remission of prediabetes compared to only 33% on the HC diet with similar weight loss.HP diet subjects had a greater increase in (1) OGTT GLP-1 AUC(p = 0.001) and MTT GLP-1 AUC(p = 0.001), (2) OGTT GIP AUC(p = 0.005) and MTT GIP AUC(p = 0.005), and a greater decrease in OGTT ghrelin AUC(p = 0.005) and MTT ghrelin AUC(p = 0.001) and BNP(p = 0.001) compared to the HC diet at 6 months.ConclusionsThis study demonstrates that the HP diet increases GLP-1 and GIP which may be responsible in part for improved insulin sensitivity and β cell function compared to the HC diet. HP ghrelin results demonstrate the HP diet can reduce hunger more effectively than the HC diet. BNP and other CVRF, metabolic parameters and oxidative stress are significantly improved compared to the HC diet.Clinicaltrials.gov identifierNCT01642849.     

Are proton pump inhibitors a new antidiabetic drug? A cross sectional study

AIM: To investigate the effect of proton pump inhibitors (PPIs) on glycemic control (HbA1c) in type 2 diabetic patients. METHODS: A crosssectional study of consecutive in-patients admitted to hospital in any department during the fi rst semester of the year 2010 who had a recent HbA1c measurement. The study excluded those with a diagnosis of hyperglycemic decompensation, diabetic onset or pregnancy. It compared HbA1c levels of those taking PPIs and those not. RESULTS: A total of 97 patients were recruited. The average HbA1C level was 7.0% ± 1.2%. Overall PPI consumption was 55.7%. HbA1c was signif icantly lower in individuals who took PPIs: -0.6%, 95% CI: -0.12 to-0.83. People who used PPIs with some type of insulin therapy had a HbA1c reduction by -0.8%, 95% CI: -0.12 to -1.48. For the rest of subgroup analysis based on the antidiabetic drug used, PPI consumption always exhibited lower HbA1c levels. CONCLUSION: PPIs seems to be consistently associated with better glycemic control in type 2 diabetes. HbA1c reduction observed is similar to incretin-based therapies.     

Changes in post-prandial glucose and pancreatic hormones,and steady-state insulin and free fatty acids after gastric bypass surgery

BackgroundChanges in the multiple mechanisms that regulate glucose metabolism after gastric bypass (RYGB) are still being unveiled. The objective of this study was to compare the changes of glucose and pancreatic hormones [C-peptide, glucagon, and pancreatic polypeptide (PP)] during a meal tolerance test (MTT) and steady-state insulin and free fatty acid (FFA) concentrations during euglycemic–hyperinsulinemic clamp 14 days and 6 months after RYGB in morbidly obese nondiabetic patients.MethodsTwo groups were studied at baseline and at 14 days: the RYGB followed by caloric restriction group (RYGB, n = 12) and the equivalent caloric restriction alone group (Diet, n = 10), to control for energy intake and weight loss. The RYGB group was studied again at 6 months to assess the changes after substantial weight loss. During MTT, the early and overall changes in glucose and pancreatic hormone concentrations were determined, and during the clamp, steady-state insulin and FFA concentrations were assessed.ResultsAfter 14 days, RYGB patients had enhanced postprandial glucose, C-peptide, and glucagon responses, and decreased postprandial PP concentrations. Steady-state insulin concentrations were decreased at 14 days only in RYGB patients, and FFA increased in both groups. Six months after RYGB and substantial weight loss, the decrease in insulin concentrations during clamp persisted, and there were further changes in postprandial glucose and glucagon responses. FFA concentrations during clamp were significantly lower at 6 months, relative to presurgical values.ConclusionsIn morbidly obese nondiabetic patients, RYGB produces early changes in postmeal glucose, C-peptide, glucagon, and PP responses, and it appears to enhance insulin clearance early after RYGB and improve insulin sensitivity in adipose tissue at 6 months postsurgery. The early changes cannot be explained by caloric restriction alone.     

新一代降血糖药—肠促胰素

肠促胰素”(incretins)是肠道在进餐后分泌的激素,能促进胰岛素的分泌,包括葡萄糖依赖性胰岛素释放肽(GIP)和胰高糖素样肽(GLP-1).二者可通过葡萄糖依赖的方式促进胰岛素分泌、抑制胰高血糖素分泌以及延缓胃排空、增强饱腹感等作用维持体内血糖的稳定.但由于天然的肠促胰素易被二肽基肽酶Ⅳ(DPP-Ⅳ)降解,半衰期短,无法用于临床治疗.因此,人们致力于研发可以用于糖尿病治疗的DPP-Ⅳ抑制剂和GLP-1类似物.本文就肠促胰素的研究现状及以肠促胰素为基础的降血糖药物的开发情况做一概述.