维生素D和糖尿病

维生素D最重要的功能是维持人体钙离子代谢的平衡.随着研究的深入,维生素D在炎性反应、自身免疫性疾病、胰岛素分泌及胰岛素抵抗等方面的作用已经成为研究的热点.维生素D缺乏或不足与糖尿病发病相关.维生素D可通过抑制炎性反应、促进胰岛素释放、减轻胰岛素抵抗等机制参与糖尿病的发病.大量的临床研究发现补充足量的维生素D不仅可以减少...     

维生素D与糖尿病和代谢综合征

自从在胰岛β细胞和免疫细胞中发现维生素D受体后,越来越多的证据表明维生素D缺乏的个体更易患糖尿病。流行病学研究显示,生命早期的维生素D缺乏与将来1型糖尿病的发病存在联系,而补充维生素D可以预防1型糖尿病,改善2型糖尿病的血糖控制。临床及动物模型研究证明,维生素D缺乏会损害胰岛素的合成和分泌,加重胰岛素抵抗,并增加代谢综合征的发病率,这表明维生素D在2型糖尿病发生和发展中具有不可忽视的作用。     

维生素D在治疗糖尿病中的作用

“维生素D可降低l型糖尿病发生的风险,同样也能改善I型糖尿病、2型糖尿病患者的血糖控制、胰岛素敏感性或胰岛素抵抗。”在阿联酋迪拜举行的第2l届世界糖尿病大会上,很多专家提出了这一观点。许多糖尿病患者都知道,缺乏维生素D会缺钙,而维生素D水平与人胰岛素的合成、分泌、生理作用及糖尿病的发病风险等的相关性却鲜为人知。     

非特异性免疫与胰岛素抵抗及2型糖尿病

越来越多的研究表明,非特异性免疫系统激活参与胰岛素抵抗和2型糖尿病的发生、发展.糖尿病患者存在细胞因子介导的慢性低度炎性反应状态,伴随着非特异性免疫系统的上调.非特异性免疫参与胰岛素抵抗和2型糖尿病发病的作用途径包括:遗传变异、巨噬细胞的促炎作用、慢性感染、Toll样受体(TLR)途径、巨噬细胞迁移抑制因子(MIF)水平增高等.通过锻炼或药物干预非特异性免疫系统有可能改善胰岛素抵抗及2型糖尿病.     

颗粒蛋白前体与糖尿病及肥胖的关系

颗粒蛋白前体是一种分泌性蛋白,广泛表达于各种组织,尤其是快速增殖的细胞中,参与胚胎发育、损伤修复、细胞周期等病理生理过程.炎性反应与2型糖尿病及肥胖相关,并且是胰岛素抵抗形成的重要机制之一.最新研究发现,颗粒蛋白前体在2型糖尿病及肥胖患者的体内表达明显升高,并通过白细胞介素-6炎性反应信号通路参与慢性炎性反应状态及胰岛素抵抗的形成,提示颗粒蛋白前体可能与2型糖尿病及肥胖的发病密切相关.     

2型糖尿病的抗炎治疗

胰岛素抵抗与胰岛β细胞功能障碍是2型糖尿病发病的主要病理生理基础,而炎性反应因子介导的慢性非特异性低度炎性反应状态与胰岛素抵抗及β细胞功能障碍密切相关.传统意义上的降糖药物如二甲双胍、噻唑烷二酮类药物、胰岛素、胰高血糖素样肽-1以及他汀类降脂药都具有抗炎效应.新型的抗炎药物如白细胞介素1受体拮抗剂、白藜芦醇、姜黄素等可以通过多种途径改善炎性反应状态而降低血糖.因此,针对炎性反应因子的抗炎治疗有望成为一种崭新的糖尿病治疗u方法.     

维生素D与2型糖尿病的临床研究进展

研究发现维生素D与2型糖尿病的发生关系密切。低维生素D血症的人群中2型糖尿病的发病率明显增高。其机制可能是低维生素D抑制胰岛素的合成和分泌,加重胰岛素抵抗而导致糖尿病的发生发展。适当补充维生素D可以增加胰岛素的敏感性,降低血糖及减少糖尿病心血管并发症。     

胰岛自身免疫与2型糖尿病

胰岛自身免疫不仅是1型糖尿病的发病基础,而且也是2型糖尿病的发病表现.研究表明,伴严重的胰岛素抵抗和β细胞功能损伤的2型糖尿病患者体内可检测到胰岛自身抗体、促炎细胞因子或胰岛反应性T细胞.这些免疫及炎性反应因子是产生胰岛自身免疫反应的关键因素,也是2型糖尿病慢性炎性反应的发病机制.因此,研究胰岛自身免疫与2型糖尿病的关系,将为2型糖尿病的治疗提供新思路.     

脂肪固有免疫细胞与胰岛素抵抗

胰岛素抵抗是指外周组织对胰岛素敏感性及反应性降低,肥胖是胰岛素抵抗的主要原因.近年来研究显示,脂肪组织内的炎性反应状态与胰岛素抵抗及2型糖尿病等代谢疾病之间存在密切关系,而脂肪组织中的巨噬细胞、肥大细胞、中性粒细胞、树突状细胞、嗜酸性粒细胞以及自然杀伤T细胞等多种固有免疫细胞通过活化和释放炎性反应介质,参与炎性反应,从而促进机体胰岛素抵抗的形成.进一步深入阐明固有免疫细胞在脂肪组织炎性反应和胰岛素抵抗方面的作用,可以为糖尿病基础研究和治疗提供新的方向和思路.     

糖尿病研究2007年回眸:流行病学和发病机制

本文比较了美国、欧洲和亚洲逐年增加的糖尿病患病率的估测报告，以警示人们更多地关注这一超出人们预测的事实。此外，还从几个方面对2型糖尿病的发病机制做了论述。内质网应激激活一系列的信号转导途径即未折叠蛋白反应（UPR），如果内质网应激不能缓解，UPR信号转导可促使凋亡细胞死亡。另外还对脂肪酸诱导脂肪细胞线粒体解耦联，腹型肥胖诱发的低水平炎性反应，来自血管周围脂肪的血管分泌信号转导和肌肉收缩引起的CaMK—MAPK—PGC一1线粒体生物合成等机制作了简要介绍。胰高血糖素样肽一1能调节胰岛B细胞的新生和增殖。c肽在单核细胞、巨噬细胞和CD4淋巴细胞趋化和动脉粥样硬化斑块的形成中都起重要的作用。胰岛素抵抗一直被视为糖尿病病因的中心，但随着体力活动减少和过度营养增加，腹型肥胖在胰岛素抵抗和其他糖尿病相关疾病发生中的作用逐渐显现。实际上，腹型肥胖，而不是胰岛素抵抗，为2型糖尿病的发病基础。     

Role of vitamin D in the pathogenesis of type 2 diabetes mellitus

Vitamin D deficiency has been shown to alter insulin synthesis and secretion in both humans and animal models. It has been reported that vitamin D deficiency may predispose to glucose intolerance, altered insulin secretion and type 2 diabetes mellitus. Vitamin D replenishment improves glycaemia and insulin secretion in patients with type 2 diabetes with established hypovitaminosis D, thereby suggesting a role for vitamin D in the pathogenesis of type 2 diabetes mellitus. The presence of vitamin D receptors (VDR) and vitamin D–binding proteins (DBP) in pancreatic tissue and the relationship between certain allelic variations in the VDR and DBP genes with glucose tolerance and insulin secretion have further supported this hypothesis. The mechanism of action of vitamin D in type 2 diabetes is thought to be mediated not only through regulation of plasma calcium levels, which regulate insulin synthesis and secretion, but also through a direct action on pancreatic β-cell function. Therefore, owing to its increasing relevance, this review focuses on the role of vitamin D in the pathogenesis of type 2 diabetes mellitus.     

Vitamin D and Type 2 Diabetes

Vitamin D has been reported to have a variety of non-skeletal actions, including on glucose metabolism. There has been increasing evidence from animal and human studies, to suggest that vitamin D may be important in modifying risk of type 2 diabetes. Vitamin D is thought to have both direct (through activation of the vitamin D receptor) and indirect (via regulation of calcium homeostasis) effects on various mechanisms related to the pathophysiology of type 2 diabetes, including pancreatic beta-cell dysfunction, impaired insulin action, and systemic inflammation. The evidence from human studies comes primarily from cross-sectional and a few prospective observational studies showing an inverse association between vitamin D status and prevalence or incidence of type 2 diabetes. While there is paucity of trials that have specifically examined the role of vitamin D in prevention or treatment of type 2 diabetes, vitamin D therapy is emerging as a feasible and cost-effective potential intervention for type 2 diabetes.     

Vitamin D in diabetes mellitus—a new field of knowledge poised for D‐velopment

This commentary reviews the current state of knowledge regarding the role of vitamin D in the pathogenesis of diabetes mellitus. In type 1 diabetes mellitus or in adult onset latent autoimmune diabetes (LADA), vitamin D exhibits immunomodulatory actions, influencing the activity of lymphocytes and interleukins. In type 2 diabetes mellitus vitamin D appears to act through different mechanisms, affecting insulin secretion and insulin sensitivity through its effects on the β cells, mediators of inflammation and parathyroid hormone. Much work remains to be done in this new field of knowledge before the role of vitamin D in the pathogenesis of diabetes mellitus is completely understood. Copyright © 2009 John Wiley & Sons, Ltd.     

Vitamin D and type 2 diabetes mellitus: where do we stand?

Aims

In-vitro and observational studies have established a link between vitamin D deficiency and different type 2 diabetes outcomes (insulin resistance, insulin secretion, glucose intolerance). Although the number of randomized controlled trials vs placebo is small, vitamin D (VTD) has been shown to prevent increases in glucose concentration and insulin resistance, enhance insulin sensitivity and reduce systolic blood pressure in type 2 diabetic patients.

Methods

In this review, we have focused on the potential mechanisms that might explain the association between VTD and type 2 diabetes mellitus (T2DM). We have also evaluated the different epidemiological and observational studies on the topic, as well as the various interventional studies.

Results

Although the in vitro studies appear to be promising in explaining the link between VTD metabolism and T2DM, the results of in vivo studies are conflicting. This could be related to differences in their methodological approaches.

Conclusion

Although more studies are needed to confirm the role of VTD in the treatment of T2DM, there is nevertheless enough evidence at this time to suggest a need to maintain 25-OH vitamin D levels in T2DM patients around 30 ng/mL over the course of a year.     

维生素D3对2型糖尿病患者血管内皮功能的保护作用

目的 探讨1,25-二羟维生素D3对2型糖尿病患者血管内皮功能的影响.方法 选取我科2009～2011年住院的2型糖尿病患者80例,随机分为治疗组和对照组各40例,在血糖稳定1周后,治疗组给予常规治疗＋骨化三醇胶丸,对照组给予常规治疗,两组患者疗程均为12周.治疗前后行内皮依赖性血管舒张功能检测,同时检测其血C反应蛋白（CRP）、白细胞介素（IL）-6水平.结果 经过12周的治疗,治疗组患者体内CRP、IL-6低于对照组（P均＜0.05）;且治疗组患者内皮依赖性血管内径变化率高于对照组（P＜0.05）.结论 维生素D3可显著改善2型糖尿病患者体内的炎症状态,并改善2型糖尿病患者血管内皮功能.     

Vitamin D and Type 2 diabetes mellitus (维生素D与2型糖尿病)

Based on increasing evidence from animal and human studies, vitamin D deficiency is now regarded as a potential risk factor for Type 2 diabetes mellitus (T2DM). Vitamin D is involved in the pathogenesis of pancreatic β‐cell dysfunction, insulin resistance, and systemic inflammation, conditions that contribute to the development of T2DM. Vitamin D can affect the progress of this disease directly through the activation of its own receptor, and indirectly via the regulation of calcium homeostasis. Observational studies have revealed the association between vitamin D deficiency and incident T2DM. More double‐blind randomized control studies that investigate the effects of vitamin D supplementation on insulin sensitivity, insulin secretion, and the occurrence of T2DM are needed.     

Effect of oral vitamin D supplementation on glycemic control in patients with type 2 diabetes mellitus with coexisting hypovitaminosis D: A parellel group placebo controlled randomized controlled pilot study

Context

Vitamin D supplementation in type 2 diabetes mellitus patients may lead to improved glycemic control by improving insulin secretion and decreasing insulin resistance.

短链脂肪酸在2型糖尿病发病机制中的作用

短链脂肪酸(SCFA)是由肠道菌群发酵膳食纤维产生的代谢产物,饮食结构变化通过改变肠道菌群结构与功能,影响SCFA的产生.近来研究发现,SCFA通过调节胃肠道激素分泌、胰岛素敏感性及糖、脂代谢,参与了2型糖尿病的发生、发展.对SCFA的深入研究,为阐明2型糖尿病发病机制及其预防和治疗提供了新的思路和靶点.     

The role of vitamin D in protecting type 1 diabetes mellitus

The relationship between autoimmune diabetes or type 1 diabetes mellitus and vitamin D has been reported in the literature. Many factors, environmental and genetic, have been known, as risk factors, to cause both type 1 diabetes and vitamin D deficiency. Vitamin D treatment has improved or prevented type 1 diabetes mellitus in animals and humans. Vitamin D also has been known to protect from autoimmune diseases in animal models. Therefore, it would be interesting to review the role of vitamin D in type 1 diabetes mellitus.