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。     

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1型糖尿病和2型糖尿病的发病，而且还可以改善糖代谢，控制糖尿病相关症状。因此，维生素D可能在预防和控制糖尿病中起重要作用。     

初诊2型糖尿病患者血清25-羟维生素D3水平与胰岛β细胞功能和胰岛素抵抗的相关性

目的 评估初诊2型糖尿病患者低维生素D血症发生率,探讨血清25-羟维生素D3与胰岛β细胞功能和胰岛素抵抗的关系.方法 入选2008年4至7月在四川省人民医院就诊的初诊2型糖尿病患者97例（糖尿病组）,其中男57例,女40例,年龄（52±10）岁.以同期健康体检者69名为对照组,其中男40名,女29名,年龄（50±11）岁.采用高压液相色谱法测定2组参试者空腹血清25-羟维生素D3水平.根据25-羟维生素D3是否＜37.5 nmol/L将糖尿病组分为低25-羟维生素D3亚组（n=61）和非低25-羟维生素D3亚组（n=36）,比较糖化血红蛋白、稳态模型胰岛素抵抗指数、胰岛β细胞功能指数、早期相胰岛素分泌指数、葡萄糖曲线下面积、胰岛素曲线下面积.采用多元逐步回归分析评价血清25-羟维生素D3与性别、年龄、体质指数、腰臀比、血压、血脂、糖化血红蛋白、胰岛素抵抗及胰岛β细胞功能的相关性.结果 糖尿病组血清25-羟维生素D3水平显著低于对照组[（36±19）nmol/L vs（80±26）nmol/L,t=-13.00,P＜0.01].糖尿病组低25-羟维生素D3的发生率为62.9%（61/97）.与非低25-羟维生素D3亚组比较,低25-羟维生素D3亚组糖化血红蛋白、葡萄糖曲线下面积较高[（10.1±3.0）% vs （7.7±2.6）%,（32±7）h·mmol-1·L-1 vs （25±7）h·mmol-1·L-1,t值分别为4.44、4.45,均P＜0.01],胰岛β细胞功能指数、早期相胰岛素分泌指数、胰岛素曲线下面积较低[21±16 vs 75±64,1.9±1.9 vs 8.3±7.7,（30±21）h·mU-1·L-1vs（104±80）h·mU-1·L-1,t值分别为-5.68、-6.81、-7.69,均P＜0.01].多元逐步回归分析显示,2型糖尿病患者早期相胰岛素分泌指数、胰岛素曲线下面积与25-羟维生素D3独立正相关（t值分别为2.21、4.67,均P＜0.01）.结论部分初诊2型糖尿病患者存在25-羟维生素D3缺乏,缺乏程度与血糖升高程度有关;25-羟维生素D3缺乏与早期相胰岛素分泌和总体胰岛素分泌下降有关.     

老龄2型糖尿病大鼠维生素D与胰岛素抵抗的关系

目的 观察老龄2型糖尿病大鼠维生素D水平与胰岛素抵抗(IR)的关系.方法 测定老龄2型糖尿病大鼠、维生素D3处理的老龄2型糖尿病大鼠、1-α(OH)D3处理的老龄2型糖尿病大鼠和正常老龄大鼠IR、血25-(OH) D3和1,25-(OH)2D3水平.正常血糖胰岛素钳夹技术(EICT)测定各组大鼠IR,用葡萄糖输注速率(GIR)表示IR情况,25-(OH)D3和1,25-(OH)2D3水平测定用放免法.结果 老龄2型糖尿病大鼠和正常老龄大鼠相比,GIR和1,25-(OH)2D3有显著降低,25-(OH)D3无显著差异.维生素D3处理的老龄2型糖尿病大鼠与老龄2型糖尿病大鼠相比,25-(OH)D3显著升高,但1,25-(OH)2D3无显著改变.1-α羟化维生素D3处理的老龄2型糖尿病大鼠与老龄2型糖尿病大鼠相比,25-(OH)D3无明显改变,1,25-(OH)2D3增加显著.维生素D3处理的老龄2型糖尿病大鼠、1-α(OH) D3处理的老龄2型糖尿病大鼠与2型糖尿病老龄大鼠相比,IR无显著差异.结论 老年2型糖尿病大鼠中维生素D与IR无显著相关性.     

维生素D——2型糖尿病的“保护伞”

维生素D是维生素家族中不可忽视的成员之一,人体钙的吸收、骨骼和牙齿的强健等都离不开它。研究发现缺乏维生素D会增加患1型糖尿病的风险,而近年来的研究表明,维生素D与2型糖尿病也有着密切的联系：维生素D摄入不足与2型糖尿病的发生有关,维生素D对2型糖尿病的发生发展具有防治作用,同时对2型糖尿病并发症或者合并症有改善作用。     

新观点

2型糖尿病和前列腺癌有关联；宝宝补维生素D能防糖尿病；美国医学专家建议：糖尿病患者早用胰岛素；男人爱好交际患心脏病风险低；嗅觉障碍可能是老年痴呆前兆；[编者按]     

如何面对维生素D缺乏

无论是1型糖尿病还是2型糖尿病,维生素D都经常被扯上关系。不管是维生素D缺乏会增加糖尿病发生风险也好,还是糖尿病患者更容易发生维生素D缺乏也好,这些年来的研究结果都告诉我们,积极处理维生素D缺乏很必要。     

医海拾贝北大核心CSCD

近日一项随机对照试验针对2型糖尿病和维生素D缺乏患者,采用胆骨化醇作为干预治疗发现,高剂量维生素D,疗法可增加2型糖尿病患者胰岛素分泌,且对B细胞功能和炎性标志物等指标没有影响（Metabolism,2014,63：1115—1124）。     

维生素D联合有氧运动对老年维生素D缺乏2型糖尿病患者胰岛素抵抗的影响

目的探讨维生素D联合有氧运动对老年维生素D缺乏2型糖尿病患者胰岛素抵抗的临床应用效果。方法选取2019年1～8月在温州医科大学附属第三医院接受治疗的150例老年维生素D缺乏2型糖尿病患者作为研究对象,随机抽取30例作为对照组,将剩余患者随机分为维生素D组、运动组及联合组各40例。维生素D组仅给予补充活性维生素D,运动组仅有氧运动干预,联合组给予补充活性维生素D并联合有氧运动干预,对照组给予与活性维生素D同规格安慰剂,对比分析4组治疗前后血清25羟维生素D[25(OH)D]、空腹血糖、空腹胰岛素、空腹C肽、糖化血红蛋白、肿瘤坏死因子(TNF)-α、白细胞介素(IL)-6的水平变化,并计算其胰岛素抵抗水平。结果治疗后,维生素D组、运动组及联合组空腹血糖、空腹胰岛素及胰岛素抵抗水平均低于治疗前,且联合组空腹血糖、空腹胰岛素及胰岛素抵抗水平均分别低于维生素D组、运动组及对照组,差异有统计学意义(P0.05);维生素D组、运动组及联合组25(OH)D、空腹C肽均高于治疗前,糖化血红蛋白低于治疗前,且联合组25(OH)D、空腹C肽均分别高于维生素D组、运动组及对照组患者,糖化血红蛋白低于维生素D组、运动组及对照组,差异有统计学意义(P0.05);维生素D组、运动组及联合组TNF-α、IL-6均低于治疗前,且联合组患者TNF-α、IL-6均分别低于维生素D组、运动组及对照组,差异有统计学意义(P0.05);对照组治疗前后上述指标对比,差异无统计学意义(P0.05)。结论对老年维生素D缺乏2型糖尿病患者使用维生素D联合有氧运动进行干预治疗,能够有效降低患者的空腹血糖水平,改善其胰岛素抵抗情况,减少炎症反应的发生,疗效显著。     

Role of Vitamin D in the Development of Insulin Resistance and Type 2 Diabetes

Vitamin D deficiency is mainly a consequence of insufficient sunlight induced vitamin D production in the skin and has been associated with various chronic diseases including type 2 diabetes. Experimental data have shown that vitamin D is important for glucose induced insulin secretion, improves insulin resistance, and exerts anti-inflammatory actions. Epidemiological studies have largely documented that a poor vitamin D status is associated with higher risk of insulin resistance and type 2 diabetes. The majority of randomized controlled trials (RCTs) in healthy or prediabetic individuals have, however, failed to demonstrate relevant vitamin D effects on insulin resistance or diabetes incidence. In patients with type 2 diabetes, a few RCTs reported some moderate effects of vitamin D on glycemic control and insulin resistance. While these findings warrant further in-depth studies, the current evidence is insufficient to recommend vitamin D supplementation for the prevention or treatment of type 2 diabetes.     

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...     

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.     

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,Insulin Resistance,and Type 2 Diabetes

Vitamin D deficiency has become a major public health problem in the United States and worldwide due to its increasing prevalence and potential health risks. There is growing evidence from experimental studies that vitamin D is essential for pancreatic insulin secretion and peripheral insulin action through binding to the vitamin D receptor (VDR). Observational evidence, primarily from cross-sectional studies, has shown that low dietary vitamin D intake or vitamin D levels are inversely related to glucose intolerance, insulin resistance, decreased insulin secretion, as well as prevalence of the metabolic syndrome. Population genetic data for an association between VDR gene polymorphisms and type 2 diabetes have been sparse and yielded inconsistent results. Prospective data, although limited, tend to support an inverse association between serum 25(OH) vitamin D levels and incident type 2 diabetes. Direct evidence from randomized trials on the effect of vitamin D supplements on insulin homeostasis, however, remains limited. Future well-designed randomized clinical trials are warranted to address the potential beneficial effect of vitamin D supplementation on preventing type 2 diabetes.     

维生素D与糖尿病关系的研究进展

维生素D（VitD）与糖尿病的发生发展密切相关,VitD缺乏或不足人群的糖尿病患病率明显高于普通人群。低VitD水平通过损害自身免疫,抑制胰岛素的合成及分泌,促进慢性炎症反应,加重胰岛素抵抗等机制而影响糖尿病的发生发展过程。适当补充VitD有助于更好地控制血糖。     

Vitamin D ratio and glycaemic control in individuals with type 2 diabetes mellitus: A systematic review

Several studies have suggested a favorable role for vitamin D in glycaemic metabolism and its potential as adjuvant treatment of type 2 diabetes mellitus. This review discusses the role of vitamin D in the glycaemic control of individuals with type 2 diabetes mellitus and evaluates the effect of vitamin D supplementation on glycaemic markers in this population. Literature searches were performed in the BIREME, LILACS, and PubMed databases using the Medical Subject Headings and words related to vitamin D, type 2 diabetes mellitus, and glycaemic control. Interventional and observational studies were considered eligible. The evaluation of the included studies was independently performed by 2 evaluators at all stages of selection, data extraction, and bias risk assessment. The primary outcome was the relationship between vitamin D levels and glucose metabolism markers in type 2 diabetes mellitus individuals. The secondary outcome was the effect of vitamin D supplementation on the glycaemic control markers in individuals with type 2 diabetes mellitus. The inverse relationship between vitamin D and variables of glucose metabolism was verified. Interventional studies revealed that vitamin D supplementation did not alter glycaemic control markers in most studies. Few studies have shown positive effects with a significant reduction in the percentage of glycated haemoglobin, insulin, and glucose concentrations, and changes in homeostatic model assessment–insulin resistance and beta cell, and quantitative insulin sensitivity check index. Therefore, despite the association of vitamin D with glucose metabolism, there is insufficient evidence of the beneficial effects of its supplementation on the metabolic control of type 2 diabetes mellitus.     

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 insulin resistance

Vitamin D is a steroid hormone, which in active form binds to the vitamin D receptor. Expression of the vitamin D receptor in diverse cell types (pancreatic islet cells, myocytes, hepatocytes and adipocytes) raises the suspicion that vitamin D may be involved in multiple cellular processes, including the response to insulin. Insulin resistance is a characteristic feature of type 2 DM, and its attenuation may reduce the incidence of type 2 DM and cardiovascular disease. In observational studies, low serum 25‐hydroxyvitamin D (25‐OHD) concentrations are associated with an increased risk of type 2 DM. It has been suggested that increasing serum 25‐OHD concentrations may have beneficial effects on glucose and insulin homeostasis. However, cross‐sectional and interventional studies of vitamin D supplementation provide conflicting results and demonstrate no clear beneficial effect of vitamin D on insulin resistance. These studies are complicated by inclusion of different patient cohorts, different 25‐OHD assays and different doses and preparations of vitamin D. Any possible association may be confounded by alterations in PTH, 1,25‐dihydroxyvitamin D or tissue vitamin D concentrations. We identified 39 studies via MEDLINE and PUBMED. We review the evidence from 10 studies (seven observational and three interventional) examining vitamin D and type 2 DM incidence, and 29 studies (one prospective observational, 12 cross‐sectional and 16 interventional trials) examining vitamin D and insulin resistance. Based on this data, it is not possible to state that vitamin D supplementation has any effect on type 2 DM incidence or on insulin resistance. Data from the multiple ongoing randomized controlled trials of vitamin D supplementation due to report over the next few years should help to clarify this area.