Insulin plus incretin:A glucose-lowering strategy for type 2-diabetes简

There are many advantages of combining incretin therapy [glucagon-like peptide-1 (GLP-1) receptor agonists and dipeptidyl peptidase-4 (DPP-4) inhibitors] with insulin therapy as a glucose-lowering strategy in type 2 diabetes. One important advantage is the complementary mode of the mechanistic action of incretin and insulin therapy. Another advantage is the reduction in risk of hypoglycemia and weight gain when adding incretin therapy to insulin. Several clinical trials have studied the addition of GLP-1 receptor agonists [exenatide BID (twice daily), lixisenatide, albiglutide] or DPP-4 inhibitors (vildagliptin, sitagliptin, saxagliptin, alogliptin, linagliptin) to ongoing insulin therapy or adding insulin to ongoing therapy with a GLP-1 receptor agonist (liraglutide). These studies show improved glycemia in the presence of limited risk for hypoglycemia and weight gain with the combination of incretin therapy with insulin. This article reviews the background and clinical studies on this combination.     

Incretin-based therapies in prediabetes: Current evidence and future perspectives

The prevalence of type 2 diabetes(T2D) is evolving globally at an alarming rate. Prediabetes is an intermediate state of glucose metabolism that exists between normal glucose tolerance(NGT) and the clinical entity of T2 D. Relentless β-cell decline and failure is responsible for the progression from NGT to prediabetes and eventually T2 D. The huge burden resulting from the complications of T2 D created the need of therapeutic strategies in an effort to prevent or delay its development. The beneficial effects of incretin-based therapies, dipeptidyl peptidase-4 inhibitors and glucagon-like peptide-1(GLP-1) receptor agonists, on β-cell function in patients with T2 D, together with their strictly glucose-depended mechanism of action, suggested their possible use in individuals with prediabetes when greater β-cell mass and function are preserved and the possibility of β-cell salvage is higher. The present paper summarizes the main molecular intracellular mechanisms through which GLP-1 exerts its activity on β-cells. It also explores the current evidence of incretin based therapies when administered in a prediabetic state, both in animal models and in humans. Finally it discusses the safety of incretin-based therapies as well as their possible role in order to delay or prevent T2 D.     

Recent advances in new-onset diabetes mellitus after kidney transplantation

A common challenge in managing kidney transplant recipients (KTR) is post-transplant diabetes mellitus (PTDM) or diabetes mellitus (DM) newly diagnosed after transplantation, in addition to known pre-existing DM. PTDM is an important risk factor for post-transplant cardiovascular (CV) disease, which adversely affects patient survival and quality of life. CV disease in KTR may manifest as ischemic heart disease, heart failure, and/or left ventricular hypertrophy. Available therapies for PTDM include most agents currently used to treat type 2 diabetes. More recently, the use of sodium glucose co-transporter 2 inhibitors (SGLT2i), glucagon-like peptide-1 receptor agonists (GLP-1 RA), and dipeptidyl peptidase 4 inhibitors (DPP4i) has cautiously extended to KTR with PTDM, even though KTR are typically excluded from large general population clinical trials. Initial evidence from observational studies seems to indicate that SGLT2i, GLP-1 RA, and DPP4i may be safe and effective for glycemic control in KTR, but their benefit in reducing CV events in this otherwise high-risk population remains unproven. These newer drugs must still be used with care due to the increased propensity of KTR for intravascular volume depletion and acute kidney injury due to diarrhea and their single-kidney status, pre-existing burden of peripheral vascular disease, urinary tract infections due to immunosuppression and a surgically altered urinary tract, erythrocytosis from calcineurin inhibitors, and reduced kidney function from acute or chronic rejection.     

Clinical effects of antidiabetic drugs on psoriasis: The perspective of evidence-based medicine

Psoriasis and diabetes shared common underlying pathophysiological mechanisms. Emerging data suggested that antidiabetic medications may improve the psoriasis severity in patients with diabetes mellitus. Several hypoglycemic agents including thiazolidinediones, glucagon-like peptide-1 receptor agonists, dipeptidyl peptidase-4 inhibitors, and biguanides have been reported to make a remarkable reduction in the Psoriasis Area and Severity Index score from baseline. This antipsoriatic effect could be mediated not only by the glucoselowering action of these agents but also via inhibition of keratinocyte over proliferation, increase expression of differentiation markers, suppression the immune inflammatory pathway, and blocking the calcium channels and mitogen-activated protein kinase signaling pathways. On the other hand, there was no significant increase in adverse reactions associated with the treatment of pioglitazone or metformin. However, previous studies often had the relatively short duration of the trials, and did not have enough power to assess recurrence of psoriasis. Potential bias in the study and missing data could undermine the reliability of the results. Therefore, the appropriately randomized controlled studies with large sample sizes and long-term durations in various psoriasis patients are warranted for further support.     

Cystic fibrosis-related diabetes: The unmet need

Cystic fibrosis(CF) is a common autosomal recessive disease. Life expectancy of patients with CF continues to improve mainly driven by the evolving therapies for CF-related organ dysfunction. The prevalence of CF-related diabetes(CFRD)increases exponentially as patients' age. Clinical care guidelines for CFRD from2010, recommend insulin as the mainstay of treatment. Many patients with CFRD may not require exogenous insulin due to the heterogeneity of this clinical entity.Maintenance of euglycemia by enhancing endogenous insulin production,secretion and degradation with novel pharmacological therapies like glucagonlike peptide-1 agonist is an option that remains to be fully explored. As such, the scope of this article will focus on our perspective of glucagon-like peptide-1 receptor agonist in the context of CFRD. Other potential options such as sodiumglucose cotransporter-2 and dipeptidyl peptidase 4 inhibitors and their impact on this patient population is limited and further studies are required.     

The efficacy and safety of dipeptidyl peptidase-4 inhibitors for treatment of type 2 diabetes mellitus patients with severe renal impairment: a meta-analysis

Aims/introduction Dipeptidyl peptidase-4 (DPP-4) inhibitors are a new class of oral antidiabetic agents, and have been increasingly and widely used in the treatment of diabetes mellitus (DM). However, information of DPP-4 inhibitors in type 2?DM patients with severe renal impairment (RI) is limited. Our study aimed to assess the efficacy and safety of DPP-4 inhibitors as compared to placebos or other hypoglycemic drugs in type 2?DM patients with severe RI. Materials and methods A meta-analysis was conducted to examine the literature comparing the effects of DPP-4 inhibitors on hemoglobin A1c (HbA1c) and fasting blood glucose (FBG). Randomized control trials (RCTs) including adults with type 2?DM and severe RI were analyzed. Safety was evaluated based on the percentage of patients who developed hypoglycemia and the occurrence of adverse events (AEs) as well as the incidence of peripheral edema, urinary tract infection, diarrhea, and death. Results Five RCTs including 503 patients were analyzed. Compared with a placebo or no treatment, DPP-4 inhibitors were associated with a larger decline in HbA1c (mean difference (MD)?=??0.57, 95% confidence interval (CI): ?0.73 to ?0.41; p?0.01) but not with FBG (MD?=??0.26, 95% CI: ?1.40 to 0.8; p?= 0.66). Compared with glipizide monotherapy, no significant differences in HbA1c (MD?=?0.15, 95% CI: ?0.19 to 0.49; p?= 0.38) or FBG (MD?=??0.26, 95% CI: ?1.16 to 0.64; p?= 0.57) were found. Similar odds of experiencing an AE were found in both the DPP-4 inhibitor groups and comparison groups. Conclusions In type 2?DM patients with severe RI, treatment with DPP-4 inhibitors is safe and it effectively lowers HbA1c.     

Treatment of type 2 diabetes,lifestyle, GLP1 agonists and DPP4 inhibitors

In recent years the treatment focus for type 2 diabetes has shifted to prevention by lifestyle change and to more aggressive reduction of blood sugars during the early stage of treatment. Weight reduction is an important goal for many people with type 2 diabetes.Bariatric surgery is no longer considered a last resort treatment. Glucagon-like peptide-1 agonists given by injection are emerging as a useful treatment since they not only lower blood sugar but are associated with a modest weight reduction. The role of the oral dipeptidyl peptidase 4 inhibitors is emerging as second line treatment ahead of sulphonylureas due to a possible beneficial effect on the beta cell and weight neutrality.Drugs which inhibit glucose re-absorption in the kidney,sodium/glucose co-transport 2 inhibitors, may have a role in the treatment of diabetes. Insulin treatment still remains the cornerstone of treatment in many patients with type 2 diabetes.     

Insulin plus incretin:A glucose-lowering strategy for type 2-diabetes

There are many advantages of combining incretin therapy[glucagon-like peptide-1(GLP-1)receptor agonists and dipeptidyl peptidase-4(DPP-4)inhibitors]with insulin therapy as a glucose-lowering strategy in type2 diabetes.One important advantage is the complementary mode of the mechanistic action of incretin and insulin therapy.Another advantage is the reduction in risk of hypoglycemia and weight gain when adding incretin therapy to insulin.Several clinical trials have studied the addition of GLP-1 receptor agonists[exenatide BID(twice daily),lixisenatide,albiglutide]or DPP-4inhibitors(vildagliptin,sitagliptin,saxagliptin,alogliptin,linagliptin)to ongoing insulin therapy or adding insulin to ongoing therapy with a GLP-1 receptor agonist(liraglutide).These studies show improved glycemia in the presence of limited risk for hypoglycemia and weight gain with the combination of incretin therapy with insulin.This article reviews the background and clinical studies on this combination.     

Crosstalk between gut microbiota and antidiabetic drug action

Type 2 diabetes(T2 D) is a disorder characterized by chronic inflated blood glucose levels(hyperglycemia), at first due to insulin resistance and unregulated insulin secretion but with tendency towards global spreading. The gut microbiota is recognized to have an influence on T2 D, although surveys have not formed a clear overview to date. Because of the interactions between gut microbiota and host homeostasis, intestinal bacteria are believed to play a large role in various diseases, including metabolic syndrome, obesity and associated disease. In this review, we highlight the animal and human studies which have elucidated the roles of metformin, α-glucosidase inhibitors, glucagon-like peptide-1 agonists,peroxisome proliferator-activated receptors γ agonists, inhibitors of dipeptidyl peptidase-4, sodium/glucose cotransporter inhibitors, and other less studied medications on gut microbiota. This review is dedicated to one of the most widespread diseases, T2 D, and the currently used antidiabetic drugs and most promising new findings. In general, the gut microbiota has been shown to have an influence on host metabolism, food consumption, satiety, glucose homoeostasis, and weight gain. Altered intestinal microbiota composition has been noticed in cardiovascular diseases, colon cancer, rheumatoid arthritis, T2 D,and obesity. Therefore, the main effect of antidiabetic drugs is on the microbiome composition, basically increasing the short-chain fatty acids-producing bacteria,responsible for losing weight and suppressing inflammation.     

Effect of vildagliptin as add-on therapy to a low-dose metformin

AIM: To evaluate the efficacy and safety of the addition of vildagliptin to low-dose metformin and compare it to an uptitration of metformin in type 2 diabetes mellitus (T2DM) patients who have inadequate control with metformin monotherapy.METHODS: Eligible patients were randomized to receive vildagliptin 100 mg qd or metformin (500 mg qd for 2 wk and then 500 mg bid) added to open label metformin 500 mg bid for the 24 wk. The primary endpoint was baseline to endpoint hemoglobin A_1c (HbA_1c) change.RESULTS: The adjusted mean change from baseline in HbA_1c at the 24th wk was -0.51% in the vildagliptin/metformin group (mean baseline HbA_1c: 7.4%) and -0.37% in the metformin monotherapy group (mean baseline HbA_1c: 7.3%). The mean difference was -0.14% with 95% Confidence Interval (-0.24%, -0.05%). As non-inferiority (margin of 0.4%) was achieved, a test for superiority was performed. This test showed statistically significant superiority of the combination over monotherapy group (P = 0.002). Gastrointestinal (GI) adverse events were significantly more frequent in the metformin group than the combination group (21.0% vs 15.4%, P = 0.032).CONCLUSION: In patients with T2DM inadequately controlled with metformin up to 1000 mg daily, the addition of vildagliptin 100 mg daily achieved larger HbA_1c reduction with fewer GI events than with increasing the metformin dose.     

Novel glucose-lowering drugs for non-alcoholic fatty liver disease

BACKGROUNDThe efficacy of novel glucose-lowering drugs in treating non-alcoholic fatty liver disease (NAFLD) is unknown.AIMTo evaluate the efficacy of glucose-lowering drugs dipeptidyl peptidase-4 (DPP-4) inhibitors, glucagon-like peptide-1 receptor agonists (GLP-1 RAs), and sodium-glucose cotransporter 2 (SGLT2) inhibitors in treating NAFLD and to perform a comparison between these treatments.METHODSElectronic databases were systematically searched. The inclusion criteria were: Randomized controlled trials comparing DPP-4 inhibitors, GLP-1 RAs, or SGLT2 inhibitors against placebo or other active glucose-lowering drugs in NAFLD patients, with outcomes of changes in liver enzyme [alanine aminotransferase (ALT) and/or aspartate aminotransferase (AST)] from baseline.RESULTSNineteen studies were finally included in this meta-analysis. Compared with placebo or other active glucose-lowering drug treatment, treatment with DPP-4 inhibitors, GLP-1 RAs, and SGLT2 inhibitors all led to a significant decrease in ALT change and AST change from baseline. The difference between the DPP-4 inhibitor and SGLT2 inhibitor groups in ALT change was significant in favor of DPP-4 inhibitor treatment (P < 0.05). The trends of reduction in magnetic resonance imaging proton density fat fraction and visceral fat area changes were also observed in all the novel glucose-lowering agent treatment groups.CONCLUSIONTreatment with DPP-4 inhibitors, GLP-1 RAs, and SGLT2 inhibitors resulted in improvements in serum ALT and AST levels and body fat composition, indicating a beneficial effect in improving liver injury and reducing liver fat in NAFLD patients.     

Prediction of the effect on antihyperglycaemic action of sitagliptin by plasma active form glucagon-like peptide-1

AIM: To investigate whether active glucagon-like peptide-1(GLP-1) is a prediction Factor of Effect of sitagliptin on patients with type 2 diabetes mellitus(GLP-1 FEST:UMIN000010645). METHODS: Seventy-six patients with type 2 diabetes, who had insufficient glycemic control [Hemoglobin A1c(Hb A1c) ≥ 7%] in spite of treatment with metformin and/or sulfonylurea, were included in the investigation. Patients were divided into three groups by tertiles of fasting plasma active GLP-1 level, before the administration of 50 mg sitagliptin. RESULTS: At baseline, body mass index, serum UA, insulin and HOMA-IR were higher in the high active GLP-1 group than in the other two groups. The high active GLP-1 group did not show any decline of Hb A1c(7.6% ± 1.4% to 7.5% ± 1.5%), whereas the middle and low groups indicated significant decline of Hb A1c(7.4 ± 0.7 to 6.8 ± 0.6 and 7.4 ± 1.2 to 6.9 ± 1.3, respectively) during six months. Only the low and middle groups showed a significant increment of active GLP-1, C-peptide level, a decreased log and proinsulin/insulin ratio after administration. In logistic analysis, the low or middle group is a significantexplanatory variable for an Hb A1 c decrease of ≥ 0.5%, and its odds ratio is 4.5(1.40-17.6)(P = 0.01) against the high active GLP-1 group. This remains independent when adjusted for Hb A1 c level before administration, patients' medical history, medications, insulin secretion and insulin resistance.CONCLUSION: Plasma fasting active GLP-1 is an independent predictive marker for the efficacy of dipeptidyl peptidase 4 inhibitor sitagliptin.     

Dipeptidyl peptidase-4 inhibitor for steroid-induced diabetes

The addition of the dipeptidyl peptidase-4 (DDP-4) inhibitor has been reported to achieve greater improvements in glucose metabolism with fewer adverse events compared to increasing the metformin dose in type 2 diabetic patients. We present a patient with steroid-induced diabetes whose blood glucose levels were ameliorated by the use of the DPP-4 inhibitor, showing that the DPP-4 inhibitors may be an effective and safe oral anti-diabetic drug for steroid-induced diabetes.     

Dipeptidyl peptidase-4 inhibitor-induced autoimmune diseases: Current evidence

Dipeptidyl peptidase-4 inhibitors (DPP-4i) have an important place in the management of type 2 diabetes. The DPP-4 enzyme is ubiquitously distributed throughout the human body and has multiple substrates through which it regulates several important physiological functions. DPP-4 regulates several immune functions, including T-cell activation, macrophage function, and secretion of cytokines. Studies have reported an increase in autoimmune diseases like bullous pemphigoid, inflammatory bowel disease, and arthritis with DPP-4i use. The relationship of DPP-4i and autoimmune diseases is a complex one and warrants further research into the effect of DPP-4 inhibition on the immune system to understand the pathogenesis more clearly. Whether a particular cluster of autoimmune diseases is associated with DPP-4i use remains an important contentious issue. Nevertheless, a heightened awareness from the clinicians is required to identify and treat any such diseases. Through this review, we explore the clinical and pathophysiological characteristics of this association in light of recent evidence.     

Coagonist of glucagon-like peptide-1 and glucagon receptors ameliorates kidney injury in murine models of obesity and diabetes mellitus

AIM To investigate the role of glucagon-like peptide-1(GLP-1)/glucagon receptors coagonist on renal dysfunction associated with diabetes and obesity. METHODS Chronic high-fat diet fed C57 BL/6 J mice, streptozotocintreated high-fat diet fed C57 BL/6 J mice and diabeticC57 BLKS/J db/db mice were used as models of diabetes-induced renal dysfunction. The streptozotocintreated high-fat diet fed mice and db/db mice were treated with the GLP-1 and glucagon receptors coagonist(Aib2 C24 Chimera2, 150 μg/kg, sc) for twelve weeks, while in chronic high-fat diet fed mice, coagonist(Aib2 C24 Chimera2, 150 μg/kg, sc) treatment was continued for forty weeks. Kidney function, histology, fibrosis, inflammation, and plasma biochemistry were assessed at the end of the treatment. RESULTS Coagonist treatment decreased body weight, plasma lipids, insulin resistance, creatinine, blood urea nitrogen, urinary albumin excretion rate and renal lipids. In kidney, expression of lipogenic genes(SREBP-1 C, FAS, and SCD-1) was decreased, and expression of genes involved in β-oxidation(CPT-1 and PPAR-α) was increased due to coagonist treatment. In plasma, coagonist treatment increased adiponectin and FGF21 and decreased IL-6 and TNF-?. Coagonist treatment reduced expression of inflammatory(TNF-α, MCP-1, and MMP-9) and pro-fibrotic(TGF-β, COL1 A1, and α-SMA) genes and also improved histological derangement in renal tissue.CONCLUSION Coagonist of GLP-1 and glucagon receptors alleviated diabetes and obesity-induced renal dysfunction by reducing glucose intolerance, obesity, and hyperlipidemia.     

艾塞那肽在PCOS治疗中的作用及应用前景

艾塞那肽(EX)是一种胰高血糖素样肽-1(GLP-1)类似物,主要用于改善Ⅱ型糖尿病血糖控制不佳及需要减重的患者,是近年来新出现的治疗糖尿病的新型靶点药物。EX具有改善胰岛β细胞的功能、促进葡萄糖依赖性胰岛素的分泌、显著降低餐后血糖、抑制胰高血糖素分泌及减重等众多作用。鉴于多囊卵巢综合征(PCOS)患者常伴有胰岛素抵抗,并且可能合并GLP-1分泌功能受损,目前,学者们开始探索将EX应用于PCOS的治疗。本综述的主要目的是初步阐明EX在PCOS患者治疗中的作用机制,并展望其在生殖内分泌领域的应用前景。     

Glucagon-like peptide 1 in the pathophysiology and pharmacotherapy of clinical obesity

Though the pathophysiology of clinical obesity is un-doubtedly multifaceted, several lines of clinical evidence implicate an important functional role for glucagon-like peptide 1(GLP-1) signalling. Clinical studies assessing GLP-1 responses in normal weight and obese subjects suggest that weight gain may induce functional deficits in GLP-1 signalling that facilitates maintenance of the obesity phenotype. In addition, genetic studies implicate a possible role for altered GLP-1 signalling as a risk factor towards the development of obesity. As reductions in functional GLP-1 signalling seem to play a role in clinical obesity, the pharmacological replenishment seems a promising target for the medical management of obesity in clinical practice. GLP-1 analogue liraglutide at a high dose(3 mg/d) has shown promising results in achieving and maintaining greater weight loss in obese individuals compared to placebo control, and currently licensed antiobesity medications. Generally well tolerated, provided that longer-term data in clinical practice supports the currently available evidence of superior short- and longterm weight loss efficacy, GLP-1 analogues provide promise towards achieving the successful, sustainable medical management of obesity that remains as yet, an unmet clinical need.     

胃旁路术治疗2型糖尿病的作用机制

目的 探讨胃旁路术治疗2型糖尿病大鼠的作用机制.方法 将72只8周龄的GK大鼠按照随机数字表法分为手术组、假手术组、饮食控制组和对照组,每组18只.手术组大鼠施行胃旁路术,假手术组大鼠施行离断胃窦十二指肠原位吻合术,饮食控制组大鼠按15 g/d控制每只大鼠进食量,对照组大鼠自由进食.术前、术后第2、4、8周检测各组大鼠空腹、餐后血糖和胰高血糖素样肽-1(GLP-1).术后第2、4、8周检测各组大鼠餐后血糖和GLP-1后处死大鼠(每组6只),取出胰腺组织采用TUNEL法检测胰岛β细胞凋亡情况.采用t检验分析数据.结果 手术组大鼠术前空腹和餐后血糖分别为(16.2±0.8)mmol/L和(31.1±1.1)mmol/L,术后第4、8周逐渐降低为(9.2±0.6)mmol/L和(13.1±0.7)mmol/L、(9.7±0.7)mmol/L和(12.3±0.7)mmol/L,手术前后比较,差异有统计学意义(t=20.7、49.7,18.8、39.0,P<0.05).手术组大鼠术后第4、8周空腹和餐后血糖水平明显低于同时相点的假手术组、饮食控制组和对照组(t=27.7、-57.8,11.3、-59.9,-27.4、-48.2,-13.2、-52.7,-7.0、-24.9,-18.2、-56.4,P<0.05).手术组大鼠术前空腹和餐后GLP-1分别为(10.7±1.0)pmol/L和(42.5±1.2)pmol/L,术后第4、8周逐渐升高为(26.1±0.9)pmol/L和(90.7±1.7)pmol/L、(25.3±1.2)pmol/L和(90.4±2.0)pmol/L,手术前后比较,差异有统计学意义(t=-42.1、-92.4,-29.1、-72.7,P<0.05).手术组大鼠术后第4、8周空腹和餐后GLP-1水平明显高于同时相点的假手术组、饮食控制组和对照组(t=48.0、61.9,38.0、62.2,50.9、65.2,37.0、48.1,27.5、51.6,17.5,52.9,P<0.05).手术组大鼠胰岛随着术后时间的延长,凋亡细胞数逐渐减少,细胞凋亡率明显降低.手术组、假手术组、饮食控制组和对照组术后第4、8周细胞凋亡率分别为5.9%±0.7%、47.2%±1.0%、21.1%±1.2%、46.5%±1.4%和6.3%±1.1%、47.2%±1.0%、21.2%±1.2%、46.0%±1.4%,手术组细胞凋亡率较同时相点的假手术组、饮食控制组、对照组明显降低(t=-82.2、-67.0,-27.1、-22.4,-55.2、-54.6,P<0.05).结论 胃旁路手术后2型糖尿病大鼠血糖降低,GLP-1分泌明显增加,可以显著抑制胰岛β细胞凋亡.

Abstract：

Objective To investigate the mechanism of gastric bypass surgery in the treatment of type 2 diabetes mellitus in a rat model. Methods Seventy-two 8-week-old GK rats were randomly divided into operation group, sham operation group, diet control group and control group (18 rats in each group) according to the random number table. Rats in the operation group and the sham operation group received gastric bypass surgery and transection and reanastomosis of the gastrointestinal tract, respectively. The food intake was set as 15 g/d for each rat in the diet control group, while rats in the control group were fed ad libitum. The levels of fasting blood glucose ( FBG), postprandial blood glucose (PPBG) and glucagon-like peptide-1 (GLP-1) were detected before operation and at postoperative week 2, 4 and 8. The levels of PPBG and GLP-1 were detected at postoperative week 2, 4 and 8, then 6 rats of each group were sacrificed to detect the apoptosis of islet B cells using the TUNEL method. All data were analyzed using the t test. Results In the operation group, the preoperative levels of FBG and PPBG were (16.2±0.8)mmol/L and (31.1 ± 1. L)mmol/L, respectively, which were significantly higher than (9.2± 0.6) mmol/L and (13.1 ±0.7) mmol/L at 4 weeks after the operation, and (9. 7 ± 0. 7) mmol/L and (12. 3 ± 0.7) mmol/L at 8 weeks after the operation (t = 20. 7, 49. 7; 18. 8, 39. 0, P < 0.05 ). The levels of FBG and PPBG before the operation and at 4 and 8 weeks after the operation in the operation group were significantly lower than those in the sham operation group, diet control group and control group at corresponding time points (t = 27.7, -57.8; 11.3, -59.9; -27.4, -48.2; -13.2, -52.7; -7.0, -24.9; -18.2, -56.4, P<0.05). In the operation group, the levels of fasting GLP-1 and postprandial GLP-1 were ( 10. 7 ± 1. 0) pmol/L and (42.5 ±1.2)pmol/L, respectively, which were significantly lower than (26. 1 ±0.9)pmol/L and (90.7 ± 1.7)pmol/L at4 weeks after the operation, and (25.3 ± 1.2)pmol/L and (90.4 ±2.0)pmol/L at 8 weeks after the operation (t=42.1, -92.4; -29.1, -72.7, P <0.05). The levels of fasting GLP-1 and postprandial GLP-1 before the operation and at 4 and 8 weeks after the peration in the operation group were significantly higher than those in the sham operation group, diet control group and control group at corresponding time points (t = 48.0, 61.9; 38.0, 62.2; 50.9, 65.2; 37.0, 48. 1; 27.5, 51.6; 17.5, 52.9, P<0.05). The number of the apoptotic islet β cells in the operation group was decreased with time. The apoptosis rates in the operation group, sham operation group, diet control group and control group were 5.9%±0.7% , 47.2%± 1.0% , 21. 1%± 1. 2% , 46.5%±1.4% at 4 weeks after the operation, and 6.3%±1. 1% , 47.2%±1.0% , 21.2%±1.2% and 46.0% ± 1.4% at 8 weeks after the operation. The apoptosis rates in the operation group were significantly lower than those in the sham operation group, diet control group and control group at corresponding time points (t = -82. 2, - 67. 0; - 27. 1, - 22. 4; - 55. 2, - 54. 6, P < 0.05). Conclusion After gastric bypass surgery, the level of blood glucose reduces and the level of GLP-1 increases which significantly inhibit the apoptosis of islet B cells in rats with type 2 diabetes mellitus.     

胃转流术对2型糖尿病大鼠的血糖及胰高血糖素样肽-1的影响

目的 观察胃转流术(GBP)对糖尿病大鼠血糖的控制效果及胰高血糖素样肽-1(GLP-1)的影响.方法 采用链脲佐菌素建立糖尿病SD大鼠模型20只,随机分为糖尿病手术组(DO组)和糖尿病对照组(DC组),另取20只非糖尿病大鼠随机分为正常对照组(NC组)和正常手术组(NO组).分别检测各组大鼠术前、术后72 h、1周、4周和8周空腹血糖水平以及血清GLP-1浓度.结果 术前DO组与DC组以及NC组与NO组大鼠空腹血糖之间的比较差异均无统计学意义(P＞0.05);DO组大鼠术后空腹血糖进行性下降,术后8周由术前的(20.84±1.98) mmol/L下降到(5.56±0.11) mmol/L(P＜0.05);DC组大鼠术前及术后各时相的差异无统计学意义(P＞0.05).DO组和NO组大鼠术后血清GLP-1浓度出现明显升高(P＜0.05),术后8周分别由术前的(7.10±0.55)、(10.73 ±0.67) pmol/L上升到(26.48±1.14)、(13.98±0.92) pmol/L(P＜0.05).结论 GBP对2型糖尿病大鼠具有明显的降糖作用,GLP-1的升高在其中起着重要作用,但对正常大鼠血糖无影响.