β-Cell regeneration: a potential cure for Type 1 diabetes

Type 1 diabetes is a direct result of an autoimmune attack directed at the pancreatic islet cells. Within the islets, which account for 5% of the total pancreatic mass, are insulin-producing β-cells crucial for normal metabolism. Upon destruction of these cells, insulin can no longer be synthesised and secreted and therefore glucose levels must be regulated via exogenous insulin. Research involving regenerating β-cells has made astounding progress in the past two decades, owing greatly to molecular biology advances, allowing investigators to discover the factors involved in the regeneration process. Factors at the DNA and protein levels have been identified and proven useful in the islet regeneration approach. Both in vivo and in vitro differentiation of non-insulin producing cells into viable islets is a promising area of Type 1 diabetes research. The process of generating islets coupled with preventing recurrent autoimmune attack has the distinct advantage over current insulin therapy because it can potentially reverse the diabetes, not just alleviate its symptoms. The focus of this review will be on recently accepted patents pertaining to regeneration therapy for Type 1 diabetes.     

Diabetic Ketoacidosis in a Patient with Type 2 Diabetes After Initiation of Sodium–Glucose Cotransporter 2 Inhibitor Treatment

Sodium–glucose cotransporter 2 inhibitors (SGLT2i) were recently introduced for the treatment of type 2 diabetes (T2D). SGLT2i lower plasma glucose by inhibiting the renal reuptake of glucose leading to glucosuria. Generally, these drugs are considered safe to use. However, recently, SGLT2i have been suggested to predispose to ketoacidosis. Here, we present a case of diabetic ketoacidosis (DKA) developed in an obese, poorly controlled male patient with T2D treated with the SGLT2i dapagliflozin. He was admitted with DKA 5 days after the initiation of treatment with the SGLT2i dapagliflozin. On admission, the primary symptoms were nausea and dizziness, and he was hypertensive (170/103) and tachycardic (119 bpm) and had mild hyperglycaemia (15.3 mmol/l), severe ketonuria and severe metabolic acidosis (pH 7.08). He responded well to infusions of insulin, glucose and saline and was discharged after 72 hr with insulin as the only glucose‐lowering therapy. After 1 month, dapagliflozin was reintroduced as add‐on to insulin with no recurrent signs of ketoacidosis. During acute illness or other conditions with increased insulin demands in diabetes, SGLT2i may predispose to the formation of ketone bodies and ensuing acidosis.     

Stem cell-based immunomodulation in type 1 diabetes: beyond the regenerative approach

Type 1 diabetes (T1D) is an autoimmune disease, leading to pancreatic β-cell destruction and loss of glycaemic control. Administration of exogenous insulin to diabetic patients prevents life-threatening metabolic derangement, but may fail to prevent other longterm complications, such as kidney failure or diabetic retinopathy. Islet transplantation is a low-risk surgical procedure, affording improved glucose homeostasis provided sufficient islets engraft in the liver. Here we review work on the use of stem cells to generate β- cells for islet transplantation, indicating the need for improved protocols for their derivation and full maturation. We also consider recent evidence indicating that adult stem/progenitor cells may affect islet transplantation by improving the viability of engrafted islets and controlling immune reactions to islet allo- and auto-antigens, extending stem-cell use in T1D beyond the regenerative approach.     

初诊2型糖尿病胰岛素短期强化治疗对胰岛β细胞功能的影响

目的观察胰岛素短期强化治疗对初诊2型糖尿病(T2DM)患者的胰岛β细胞功能的影响。方法对空腹血糖(FPG)≥10mmol/L的35例住院初诊断T2DM患者行胰岛素强化治疗,治疗前及治疗血糖达标后行糖化血红蛋白(HbAlc)、口服葡萄糖耐量试验(OGTT)、胰岛素释放试验(OGIRT)检测;对血糖控制情况、胰岛β细胞功能指数(HOMA-β)、胰岛素抵抗指数(HOMA-IR)、早时相胰岛素分泌指数(△I30/△G30)进行比较。结果治疗后HbAlc、OGTT各时点血糖和HOMA-IR均明显降低(P<0.05),OGIRT各时点胰岛素(Ins)、HOMA-β和△I30/△G30明显升高(P<0.05)。结论短期胰岛素强化治疗对新诊断T2DM是既安全又能有效控制血糖水平、减低胰岛素抵抗、使胰岛β细胞功能恢复的治疗方案,对延缓糖尿病自然病程的进程,预防糖尿病慢性并发症有积极的意义。     

Toward a cell-based cure for diabetes: advances in production and transplant of beta cells

Type 1 diabetes results from autoimmune destruction of the insulin-producing beta cells of the pancreatic islets of Langerhans. Although developments in exogenous insulin therapy have greatly improved clinical outcomes in patients with diabetes, the ability of the pancreatic beta cell to exquisitely regulate the delivery of insulin and maintain normal levels of blood glucose is still far superior to what can be achieved by external delivery of insulin. As a result, the majority of patients with type 1 diabetes still experience the complications of chronic hyperglycemia or serious and potentially life-threatening hypoglycemia. The shortcomings of medical therapy have driven research toward more direct approaches of beta cell replacement. Indeed, the specificity of beta cell loss in type 1 diabetes makes this disease a particularly attractive candidate for cell-based therapies. In order for significant progress to be made, however, a thorough understanding of beta cell biology and more broadly islet biology is necessary. This review addresses recent advances in developmental biology that have expanded our understanding of islet cell differentiation, assesses the promise and limitations of islet transplantation, and discusses the future of alternative sources of beta cells, including directed differentiation of stem cells, replication of adult beta cells, and transdifferentiation of nonislet cells to a beta cell fate. =     

Research and development of glucokinase activators for diabetes therapy: theoretical and practical aspects

Glucokinase Glucokinase (GK GK ; EC 2.7.1.1.) phosphorylates and regulates glucose metabolism in insulin-producing pancreatic beta-cells, hepatocytes, and certain cells of the endocrine and nervous systems allowing it to play a central role in glucose homeostasis glucose homeostasis . Most importantly, it serves as glucose sensor glucose sensor in pancreatic beta-cells mediating glucose-stimulated insulin biosynthesis and release and it governs the capacity of the liver to convert glucose to glycogen. Activating and inactivating mutations of the glucokinase gene cause autosomal dominant hyperinsulinemic hypoglycemia and hypoinsulinemic hyperglycemia in humans, respectively, illustrating the preeminent role of glucokinase in the regulation of blood glucose and also identifying the enzyme as a potential target for developing antidiabetic drugs antidiabetic drugs . Small molecules called glucokinase activators (GKAs) glucokinase activators (GKAs) which bind to an allosteric activator allosteric activator site of the enzyme have indeed been discovered and hold great promise as new antidiabetic agents. GKAs increase the enzyme's affinity for glucose and also its maximal catalytic rate. Consequently, they stimulate insulin biosynthesis and secretion, enhance hepatic glucose uptake, and augment glucose metabolism and related processes in other glucokinase-expressing cells. Manifestations of these effects, most prominently a lowering of blood glucose, are observed in normal laboratory animals and man but also in animal models of diabetes and patients with type 2 diabetes mellitus (T2DM T2DM ) type 2 diabetes mellitus (T2DM) . These compelling concepts and results sustain a strong R&D effort by many pharmaceutical companies to generate GKAs with characteristics allowing for a novel drug treatment of T2DM.     

Adverse hepatic and cardiac responses to rosiglitazone in a new mouse model of type 2 diabetes: relation to dysregulated phosphatidylcholine metabolism

Given the heterogeneous nature of metabolic dysfunctions associated with insulin resistance and type 2 diabetes (T2D), a single pharmaceutical cannot be expected to provide complication-free therapy in all patients. Thiazolidinediones (TZD) increase insulin sensitivity, reduce blood glucose and improve cardiovascular parameters. However, in addition to increasing fat mass, TZD have the potential in certain individuals to exacerbate underlying hepatosteatosis and diabetic cardiomyopathy. Pharmacogenetics should allow patient selection to maximize therapy and minimize risk. To this end, we have combined two genetically diverse inbred strains, NON/Lt and NZO/Lt, to produce a "negative heterosis" increasing the frequency of T2D in F1 males. As in humans with T2D, treatment of diabetic and hyperlipemic F1 males with rosiglitazone (Rosi), an agonist of peroxisome proliferator-activated gamma receptor (PPARgamma), reverses these disease phenotypes. However, the hybrid genome perturbed both major pathways for phosphatidylcholine (PC) biosynthesis in the liver, and effected remarkable alterations in the composition of cardiolipin in heart mitochondria. These metabolic defects severely exacerbated an underlying hepatosteatosis and increased levels of the adipokine, plasminogen activator inhibitor-1 (PAI-1), a risk factor for cardiovascular events. This model system demonstrates how the power of mouse genetics can be used to identify the metabolic signatures of individuals who may be prone to drug side effects.     

胰岛素对2型糖尿病患者胰岛A细胞分泌功能的影响

目的探讨胰岛素对2型糖尿病患者胰岛A细胞的分泌功能的影响。方法 2型糖尿病患者44例、健康体检者15例,其中44例糖尿病患者按治疗前空腹C肽水平分成低水平C肽组(D1)、中等水平C肽组(D2)、高水平C肽组(D3)。测定受试者晨间空腹血糖、胰岛素、C肽、胰高血糖素。糖尿病各组给予预混人胰岛素诺和灵30R替代治疗,根据血糖水平调节胰岛素用量,使用4周后停药24h后复查上述指标,观察治疗前后各指标的变化。结果①胰岛素治疗前糖尿病各组胰高血糖素水平均显著高于正常对照组(P<0.05)。②经胰岛素治疗4周后,糖尿病各组血浆胰高血糖素水平均下降,其中D1、D2组下降明显(P<0.05),而D3组下降不显著(P>0.05)。③治疗后糖尿病组3组间的胰高血糖素值差异不明显(P>0.05)。④糖尿病各组的治疗后的胰高血糖素值与对照组差异不显著(P均>0.05)。结论①外源性胰岛素的治疗可改善A细胞的分泌异常,部分纠正高胰高血糖素血症。②胰岛素治疗的尽早使用有利A细胞分泌异常的恢复。     

Role and regulation of acylethanolamides in energy balance: focus on adipocytes and beta-cells

The endocannabinoid, arachidonoylethanolamide (AEA), and the peroxisome proliferator-activated receptor (PPAR)-alpha ligand, oleylethanolamide (OEA) produce opposite effects on lipogenesis. The regulation of OEA and its anti-inflammatory congener, palmitoylethanolamide (PEA), in adipocytes and pancreatic beta-cells has not been investigated. We report here the results of studies on acylethanolamide regulation in these cells during obesity and hyperglycaemia, and provide an overview of acylethanolamide role in metabolic control. We analysed by liquid chromatography-mass spectrometry OEA and PEA levels in: 1) mouse 3T3F442A adipocytes during insulin-induced differentiation, 2) rat insulinoma RIN m5F beta-cells kept in 'low' or 'high' glucose, 3) adipose tissue and pancreas of mice with high fat diet-induced obesity (DIO), and 4) in visceral fat or blood of obese or type 2 diabetes (T2D) patients. In adipocytes, OEA levels remain unchanged during differentiation, whereas those of PEA decrease significantly, and are under the negative control of both leptin and PPAR-gamma. PEA is significantly downregulated in subcutaneous adipose tissue of DIO mice. In RIN m5F insulinoma beta-cells, OEA and PEA levels are inhibited by 'very high' glucose, this effect being enhanced by insulin, whereas in cells kept for 24 h in 'high' glucose, they are stimulated by both glucose and insulin. Elevated OEA and PEA levels are found in the blood of T2D patients. Reduced PEA levels in hypertrophic adipocytes might play a role in obesity-related pro-inflammatory states. In beta-cells and human blood, OEA and PEA are down- or up-regulated under conditions of transient or chronic hyperglycaemia, respectively.     

Feasibility and outcomes of insulin therapy in elderly patients with diabetes mellitus.

The use of insulin in elderly patients raises special considerations. Most people who develop diabetes mellitus late in life have type 2 diabetes mellitus, in which there is some residual endogenous insulin secretion. This pancreatic insulin secretion, when present, stabilises their metabolic status. However, some elderly people lose virtually all their endogenous insulin secretory capacity over time, or may even have type 1 (autoimmune) diabetes mellitus with no endogenous insulin. Generally, older patients with diabetes mellitus can be managed for years, often decades, with nutritional therapy and oral agents. More options exist now than did previously. In addition to a variety of sulfonylureas, there is metformin, troglitazone, and/or alpha-glucosidase inhibitors, that are viable options to be used before turning to insulin. The goals of insulin therapy in the elderly must be considered. When hyperglycaemia causes symptoms (polyuria, polydypsia and bodyweight loss) blood glucose levels are generally >200 mg/dl, and insulin is needed if maximal doses of oral agents have been used. Insulin is also indicated when hyperglycaemia puts patients at risk of hyperosmolar states, for example, when blood glucose is >300 mg/dl during a normal day. Clinical judgement dictates whether to use insulin to control glycaemia in the attempt to avoid long term complications such as neuropathy, retinopathy or nephropathy. In people with relatively short life expectancy, major comorbities and no sign of diabetic complications, the risk may be small. On the other hand, in patients for whom neuropathy, in particular, is a major risk, controlling glycaemia (with insulin if necessary) does reduce that risk. Most patients with type 2 diabetes mellitus can be managed with relatively simple insulin regimens thanks to their endogenous insulin secretion. A single bedtime dose of neutral protamine Hagedorn (NPH) insulin, with or without continuation of daytime oral agents, may control fasting blood glucose. A pre-mix combination of NPH and Regular insulin such as 70/30 or 50/50 may be used pre-meal. More customised, 'intensive' insulin regimens are needed when the glycaemia is unstable. Hypoglycaemia is clearly the most significant risk of insulin therapy. If mild and easily treated, it is of no real concern. On the other hand, nocturnal hypoglycaemia, and, in particular, hypoglycaemia unawareness, are clear signs that the insulin regimen should be modified. In summary, insulin therapy may be necessary, and can be used effectively, in elderly patients. However, risk:benefit considerations must be taken into account when deciding which patients to treat with insulin and what insulin regimen to use.     

Differential anti-diabetic effects and mechanism of action of charantin-rich extract of Taiwanese Momordica charantia between type 1 and type 2 diabetic mice

Momordica charantia Linn. (Cucurbitaceae), also called bitter melon, has traditionally been used as a natural anti-diabetic agent for anti-hyperglycemic activity in several animal models and clinical trials. We investigated the differences in the anti-diabetic properties and mechanism of action of Taiwanese M. charantia (MC) between type 1 diabetic (T1D) and type 2 diabetic (T2D) mice. To clarify the beneficial effects of MC, we measured non-fasting glucose, oral glucose tolerance, and plasma insulin levels in KK/HIJ mice with high-fat diet-induced diabetes (200 mg/kg/day of charantin-rich extract of MC [CEMC]) and in ICR mice with STZ-induced diabetes. After 8 weeks, all the mice were exsanguinated, and the expression of the insulin-signaling-associated proteins in their tissue was evaluated, in coordination with the protective effects of CEMC against pancreatic β-cell toxicity (in vitro). Eight weeks of data indicated that CEMC caused a significant decline in non-fasting blood glucose, plasma glucose intolerance, and insulin resistance in the KK/HIJ mice, but not in the ICR mice. Furthermore, CEMC decreased plasma insulin and promoted the sensitivity of insulin by increasing the expression of GLUT4 in the skeletal muscle and of IRS-1 in the liver of KK/HIJ mice; however, CEMC extract had no effect on the insulin sensitivity of ICR mice. In vitro study showed that CEMC prevented pancreatic β cells from high-glucose-induced cytotoxicity after 24 h of incubation, but the protective effect was not detectable after 72 h. Collectively, the hypoglycemic effects of CEMC suggest that it has potential for increasing insulin sensitivity in patients with T2D rather than for protecting patients with T1D against β-cell dysfunction.     

Kidney and pancreas transplantation in type 1 diabetes mellitus

Type 1 diabetes mellitus is characterized by autoimmune destruction of pancreatic beta cells, leading to a state of absolute insulin deficiency. Glycemic control via the use of exogenous insulin injections is often imperfect, resulting in multiple long-term complications, such as retinopathy, neuropathy, vasculopathy, and nephropathy. The Diabetes Control and Complications Trial has provided conclusive evidence that better glycemic control by intensive insulin treatment effectively delays the onset and slows the progression of diabetic retinopathy, nephropathy, and neuropathy in patients with insulin-dependent diabetes mellitus. At this moment, the only reliable option for achieving long-term insulin independence is whole-pancreas transplantation. The proposed benefits of pancreas transplantation are clear: improved quality of life, prevention of recurrent diabetic nephropathy, freedom from exogenous insulin with euglycemia and normalization of glycosylated hemoglobin, less stringent dietary restrictions, less frequent blood glucose monitoring, and stabilization of or improvement in secondary complications. The trade-offs to the patient are the operative risk, the need for chronic immunosuppression, and the inherent side effects of chronic immunosuppression.     

Therapeutics in pediatric diabetes: insulin and non-insulin approaches. Part of a series on Pediatric Pharmacology, guest edited by Gianvincenzo Zuccotti, Emilio Clementi, and Massimo Molteni

Treatment of pediatric diabetes can be challenging. Strict glucose control can be accompanied by hypoglycemia and weight gain. Recently, there have been many developments in insulin preparations and delivery methods which make insulin levels more close to a physiologic pattern. Newly developed rapid/long acting analogues and delivery devices such as continuous subcutaneous insulin infusion (CSII, insulin pump) may reduce hypoglycemia and improve glycemic control. CSII combined with continuous glucose monitoring can achieve even better glycemic control. The closed-loop system is rapidly evolving and an artificial pancreas will be available in the near future. It is now recognized that several hormones other than insulin such as glucagon, amylin, and incretins contribute to glucose homeostasis. The role of co-adjuncts such as metformin, amylin analogues, and incretin based therapy is now emerging. Immunotherapy in a high risk population or patients in the early phase of type 1 diabetes may prevent further destruction of pancreatic β cells.     

Can targeting SIRT-1 to treat type 2 diabetes be a good strategy? A review

INTRODUCTION: Dysregulation of metabolic pathways, caused by imbalances in energy homeostasis, leads to type 2 diabetes characterized by high glucose concentration in the blood due to insulin resistance which is a major disorder in developed countries. AREAS COVERED: One of the recent treatment strategies is using activators of SIRT1, which has been in clinical trials. Many of the cellular processes including insulin secretion, cell cycle, and apoptosis are imperatively regulated by a family of mediators called sirtuins. First known mammalian sirtuin, SIRT1 is a positive regulator of insulin secretion, which triggers glucose uptake and utilization. Since the past decade, a major outstanding question is whether SIRT1 activation is a safe therapy for human diseases such as type 2 diabetes? This review summarizes and discusses the advances of the past decade and the challenges that will brazen out perplexity about homeostasis and metabolic pathways linked to SIRT1 and type 2 diabetes. Furthermore, we described the interlink between SIRT1 metabolic pathways of various tissues such as pancreas, skeletal muscle, adipose tissue and liver. EXPERT OPINION: However be the complexity of the pathways involved, T2DM regulated by SIRT1 affected metabolism is dropping down progressively due to profound research. In the context of interlinking all the SIRT1 pathways in T2DM we found various crucial intermediaries in metabolic tissues, which can also be targeted for future prospects.     

TGF-β engineered mesenchymal stem cells (TGF-β/MSCs) for treatment of Type 1 diabetes (T1D) mice model

ObjectiveMesenchymal stem cells (MSCs) are advantageous candidates for cell therapy of Type 1 diabetes (T1D). Considering immunomodulatory effect of MSC, in this study, we engineered MSCs with TGF-β gene to increase MSC potency for T1D therapy in mouse model.Materials and methodsTwo plans were designed for prevention and treatment of diabetes, respectively. In both of them, MSCs were injected i.v. and then, the diabetes features including serum insulin, blood glucose, glucose tolerance, splenocytes proliferation, and IL-4/IFN-γ production were evaluated.ResultsTGF-β/MSCs treatment program resulted in the restoration of serum glucose after 3 weeks, while prevention program could delay diabetes progression for two weeks. TGF-β/MSCs treatment elevated the levels of serum insulin and Th2 cytokine shift on 5th week after start of treatment. TGF-β/MSCs (and MSCs alone) could also diminish body weight and enhance mice survival comparing to untreated diabetic mice.ConclusionEngineered TGF-β/MSCs could restore some T1D features, including the regulation of adverse immune responses and could be potent tools for cell therapy of T1D comparing MSCs alone.     

Lotus (Nelumbo nucifera Gaertn) plumule polysaccharide ameliorates pancreatic islets loss and serum lipid profiles in non-obese diabetic mice

To unravel possible protective effects of a newly isolated lotus plumule polysaccharide (LPPS) on type 1 diabetes (T1D), this study isolated LPPS and administered it to non-obese diabetic (NOD) female mice for 15 weeks. Oral glucose tolerance, serum ketone body, glucose, insulin, and lipid levels, as well as pancreatic islet cell numbers and the insulin secretion ability of the experimental mice were determined. The results showed that LPPS administration in vivo significantly (P < 0.05) increased pancreatic islet cell numbers and slightly enhanced the basal insulin secretion ability compared to the control group. LPPS administration improved serum lipid profiles in the diabetic mice via relatively increasing serum high density lipoprotein-cholesterol, but decreasing low density lipoprotein-cholesterol and total cholesterol levels. The present study suggests that LPPS supplementation may ameliorate T1D progress and its complications through protecting pancreatic islets and modulating serum lipid profiles.     

IL-20 contributes to low grade inflammation and weight gain in the Psammomys obesus

The metabolic syndrome has been demonstrated in gene deficient animals, e.g. db/db mice, to include a systemic inflammation leading to insulin resistance, obesity and type 2 diabetes (T2D). To determine the importance of inflammation in obesity and diabetes, in a normal non-genetically modified species, an intervention study with neutralizing anti-IL-20 antibodies was conducted in the spontaneous T2D model Psammomys obesus.All IL-20 receptor chains were expressed on protein level in the Psammomys obesus. Neutralization of IL-20 did not modulate blood glucose, HbA1c, insulin levels or lymphocyte numbers after five weeks treatment although a trend to reduced weight gain rate was observed upon anti-IL-20 treatment. Inhibition of IL-20 significantly increased the number of CD11b^high/low cells and the CD11bGr-1^int myeloid derived suppressor cells in the spleen. Importantly, although the number of M1-like monocytes remained unchanged the M1-like marker CD11c expression level was reduced on the cells upon anti-IL-20 treatment. Anti-IL-20 treatment reduced both TLR4 and CCR2b expression on the macrophages upon treatment. Further, a marked shift in the protein signature in the pancreatic tissue after anti-IL-20 treatment was observed including enhanced expression of CXCL12, TIMP-1 and IL-10 while IL-1β, CXCL4, PEDF and ADAMTS1 were reduced.In conclusion, we describe for the first time the systemic immune response in the diabetic Psammomys obesus. Neutralizing IL-20 modulated the myeloid compartment, the adaptive immunity, and local expression of proteins in the diabetic pancreatic tissue as well as improved on weight gain and hence may place IL-20 as a cytokine to be considered in obesity.     

Peptide immunotherapies in Type 1 diabetes: lessons from animal models

Insulin dependent diabetes mellitus (Type 1 diabetes, T1D) is a chronic autoimmune disorder characterized by the destruction of insulin-producing pancreatic beta cells by proinflammatory autoreactive T cells. In the past, several therapeutic approaches have been exploited by immunologists aiming to regulate the autoimmune response; this can occur by deleting lymphocyte subsets and/or re-establishing immune tolerance via activation of regulatory T cells. The use of broad immunosuppressive drugs was the first approach to be explored. Subsequently, antibody-based immunotherapies failed to discriminate between autoreactive versus non-autoimmune effectors. Antigen-based immunotherapy is a third approach developed to manipulate beta cell autoimmunity. This approach allows the selective targeting of disease-relevant T cells, while leaving the remainder of the immune system intact. Animal models have been successfully employed to prevent or treat T1D by injection of either the self proteins or peptides derived from them. Peptide immunotherapies have been mainly experimented in the NOD mouse spontaneous model of disease. In this review we therefore report the main approaches that rely on the use of peptides obtained from relevant autoantigens such as glutamic acid decarboxylase, isoform 65 (GAD65), insulin, proinsulin and islet-specific glucose 6 phosphatase catalytic subunit-related protein (IGRP). Protective peptides have proven to be effective in treating or delaying the diabetic process. We also highlight the main difficulties encountered in extrapolating data to guide clinical translational investigations in humans.     

Amylin replacement with pramlintide as an adjunct to insulin therapy in type 1 and type 2 diabetes mellitus: a physiological approach toward improved metabolic control

Destruction and dysfunction of pancreatic beta-cells, resulting in absolute and relative insulin deficiency, represent key abnormalities in the pathogenesis of type 1 and type 2 diabetes, respectively. Following the discovery of amylin, a second beta-cell hormone that is co-secreted with insulin in response to nutrient stimuli, it was realized that diabetes represents a state of bihormonal beta cell deficiency and that lack of amylin action may contribute to abnormal glucose homeostasis. Experimental studies show that amylin acts as a neuroendocrine hormone that complements the effects of insulin in postprandial glucose regulation through several centrally mediated effects. These include a suppression of postprandial glucagon secretion and a vagus-mediated regulation of gastric emptying, thereby helping to control the influx of endogenous and exogenous glucose, respectively. In animal studies, amylin has also been shown to reduce food intake and body weight, consistent with an additional satiety effect. Pramlintide is a soluble, non-aggregating, injectable, synthetic analog of human amylin currently under development for the treatment of type 1 and insulin-using type 2 diabetes. Long-term clinical studies have consistently demonstrated that pre-prandial s.c. injections of pramlintide, in addition to the current insulin regimen, reduce HbA(1c) and body weight in type 1 and type 2 diabetic patients, without an increase in insulin use or in the event rate of severe hypoglycemia. The most commonly observed side effects were gastrointestinal-related, mainly mild nausea, which typically occurred upon initiation of treatment and resolved within days or weeks. Amylin replacement with pramlintide as an adjunct to insulin therapy is a novel physiological approach toward improved long-term glycemic and weight control in patients with type 1 and type 2 diabetes.