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.     

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.     

2型糖尿病患者维生素D缺乏的调查分析

目的 调查分析2型糖尿病患者血清25羟维生素D3[25（OH）D3]的水平和缺乏程度,初步了解维生素D缺乏与糖尿病病程和糖化血红蛋白（HbA1c）的关系.方法 选择天津医科大学总医院2型糖尿病患者140例,其中男60例,女80例,年龄21～89岁,平均（58.25±13.76）岁.分析不同年龄组即＜50岁、≥50且＜70岁、≥70岁者,不同检测季节组即冬春季和夏秋季两组,不同糖尿病病程组即＜10年、≥10且＜20年、≥20年,及不同HbA1c水平组即＜7％、≥7％且＜10％、≥10％的血清25（OH）D3水平.结果 （1）140例患者血清25（OH）D3水平均明显降低[（40.07±16.12）nmol/L],维生素D严重缺乏者占13.57％,缺乏者占67.86％,充足者仅占4.29％,不同性别患者维生素D水平和缺乏程度的差异均无统计学意义（t =0.803,x2=0.189,P均＞0.05）.（2）男性≥50且＜70岁组25（OH）D3水平较＜50岁组明显降低（F=2.362,P＜0.05）;女性≥50岁的两组患者25（OH）D3水平均较＜50岁组明显降低（F =3.928,P＜0.05）,维生素D缺乏者的比例均较＜50岁组显著增多（x2=10.036,P ＜0.01）.（3）冬春季组25（OH）D3水平显著低于夏秋季组（t=-4.681,P＜0.01）,严重缺乏者和缺乏者的比例也明显增加（x2=18.202,P＜0.01）.（4）病程≥10年的两组患者25（OH）D3水平均较＜10年组明显下降（F =5.489,P＜0.05）,≥20年组严重缺乏者的比例也多于＜10年组（x2=7.284,P＜0.05）.（5）HbA1c≥7％的两组患者25（OH）D3水平均较＜7％组明显下降（F=3.963,P均＜0.01）,其严重缺乏者和缺乏者的比例也较＜7％组明显增加（x2=6.712,P＜0.05）.结论 2型糖尿病患者普遍存在维生素D缺乏,尤其是病程长和持续血糖控制不佳者,特别需加强冬季维生素D的检测和补充.     

Vitamin D receptor methylation attenuates the association between physical activity and type 2 diabetes mellitus: A case‐control study

BackgroundPhysical activity and vitamin D receptor (VDR) have been associated with type 2 diabetes mellitus (T2DM). However, the associations of VDR methylation with T2DM and physical activity remained unknown. We aimed to investigate whether VDR methylation was a link between physical activity and T2DM.MethodsA 1:1 matching case‐control study was designed based on the Henan Rural Cohort Study, including 272 pairs of T2DM patients and nonpatients. Physical activity level was assessed using the International Physical Activity Questionnaire. The high‐resolution melt method was applied to determine the methylation level of the promoter region of VDR. The association between physical activity and T2DM was analyzed with a conditional logistic regression model. The effect modification of VDR methylation levels on the association between physical activity and T2DM was conducted. A multivariate correlation analysis model was applied to investigate correlations of VDR methylation with insulin sensitivity.ResultsPhysical activity level was associated with T2DM risk (crude model: odds ratio [OR] 0.611; 95% CI, 0.416‐0.897; adjusted model: OR 0.619; 95% CI, 0.418‐0.917). In effect modification analysis, the effects of physical activity on T2DM were stronger for low VDR methylation levels than for high (P = .025). Moreover, VDR methylation levels were associated with insulin (r = −0.089, P = .039) as well as homeostatic model assessment of insulin resistance (r = −0.098, P = .022).ConclusionsThe methylation status of the VDR promoter is associated with the secretion and sensitivity of insulin. VDR methylation attenuates the association between physical activity and T2DM, indicating that proactively physical activity may reduce the risk of T2DM, especially in people with low VDR methylation level.     

The vitamin D receptor gene variant is associated with the prevalence of type 2 diabetes mellitus and coronary artery disease.

AIMS: Vitamin D can influence lipolysis and insulin secretion. A common genetic polymorphism of the vitamin D receptor, which has been found to be associated with bone mineral density, has also been reported to be associated with insulin-dependent diabetes mellitus. To test the influence of the vitamin D receptor polymorphism on the prevalence of Type 2 diabetes mellitus and coronary artery disease we studied a population of high-risk patients, who were referred to our clinic for diagnostic coronary angiography. METHODS: A total of 293 patients considered at high risk for coronary artery disease because of angina pectoris and known hypercholesterolaemia underwent diagnostic coronary angiography. The BsmI vitamin D receptor polymorphism was analysed by polymerase chain reaction. RESULTS: Prevalence of Type 2 diabetes mellitus and coronary artery disease was gradually dependent on the number of B alleles (BB 28%, Bb 13%, bb 8% for Type 2 diabetes mellitus, P = 0.002; BB 88% Bb 72%, bb 66% coronary artery disease, P = 0.01). Patients with the BB genotype had an odds ratio of 3.64 (95% confidence interval 1.53-8.55, P = 0.002) to have Type 2 diabetes mellitus compared with patients with the bb genotype. CONCLUSIONS: The genotype of the vitamin D receptor polymorphism determines the prevalence of Type 2 diabetes mellitus and coronary artery disease in a high-risk cohort population.     

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。     

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...     

The association between 25-hydroxy vitamin D deficiency and diabetic complications in patients with type 2 diabetes mellitus

AimsTo evaluation the relationship between serum 25-hydroxy vitamin D [25-(OH)D] deficiency and diabetic complications in patients with type 2 diabetes (T2DM).MethodsOne hundred and sixty three patients with T2DM [DM + uncomplicated (n = 36), DM + nephropathy (n = 31), DM + neuropathy (n = 30), DM + retinopathy (n = 30), DM + cardiovascular disease (CAD) (n = 36)], 35 CAD and 40 healthy volunteers were included.ResultsSerum 25-(OH)D levels were found as significantly lower in all patients compared to the control group (p < 0.05). 25-(OH)D in patients with DM + retinopathy (p < 0.006), DM + nephropathy (p < 0.001) and DM + neuropathy (p < 0.001) was significantly lower than that of the control group. 25-(OH)D in patients with DM + nephropathy (p < 0.001), DM + neuropathy (p < 0.01) and DM + retinopathy (p < 0.001) was significantly lower than in the DM + uncomplicated group. 25-(OH)D levels were found as significantly lower in DM + CAD compared to the CAD group (p < 0.01). Serum 25-(OH)D and HbA1c and parathyroid hormone (PTH) were found to be negatively correlated with each other in DM + all complications.ConclusionsLow serum 25-OHD levels were found to be associated with the development of diabetes and complications. Low serum 25-OHD levels may be a consequence of even worse metabolic control of diabetes.     

D2S140基因多态性与2型糖尿病的相关性研究

目的：探讨D2S140基因多态性与2型糖尿病的关系。方法：运用聚合酶链反应（PCR）技术,结合短串联重复序列（STR）多态性标记的方法,检测了103例2型糖尿病患者和105例正常对照者的D2S140等位基因及基因型,结果：发现7种等 位基因。等位基因2与2型糖尿病呈显著性正相关（RR＝13。76,P＜0．001）,等位基因6与2型糖尿病呈显著性负相关（RR＝0．25,P＜0．001）。多因素非条件Logistic回归分析表明,D2S140等位基因2是2型糖尿病的独立危险因素,其相对危险度明显高于环境因素。结论：DS2S140基因多态性与中国人2型糖尿病相关。     

Determinants of ADP-induced platelet aggregation in diabetes mellitus

Summary ADP-induced platelet aggregation was measured in 15 Type 1 (insulin-dependent) diabetic patients, 15 Type 2 (non-insulin-dependent) diabetic patients and in 15 non-diabetic control subjects. Simultaneous measurements were made of fasting blood glucose, glycosylated haemoglobin, serum insulin, total plasma cholesterol, cholesterol in the lipoprotein subfractions, total triglycerides and platelet phospholipid fatty acid levels. Regression analysis of aggregation against the biochemical variables within the three groups revealed that there was no significant difference in the associations with aggregation between the groups. When the data was pooled, blood glucose (p<0.01) and glycosylated haemoglobin (p<0.05) demonstrated significant associations with aggregation. Multiple regression analysis was then applied; only blood glucose (p<0.05) had an independent effect on aggregation. Platelet aggregation in diabetic patients and non-diabetic patients appears to be related directly only to blood glucose levels.     

三维可视化技术联合多层螺旋CT对2型糖尿病患者的评估

目前糖尿病已成为威胁我国公共健康的主要疾病,众所周知,糖尿病及其导致的并发症将严重影响患者的生活质量,早期糖尿病患者可以通过调整饮食、适量增加运动以及合理使用药物控制血糖的升高,然而许多糖尿病患者当疾病进展到一定程度时才会去医院就诊。因此,临床需要寻找一种客观的方法对患者病情进行评价,进而预防性的应用治疗药物,避免血糖恶化而导致的并发症。有研究表明,在2型糖尿病(type 2 diabetes mellitus,T2DM)的进展过程中,患者胰腺在形态学上会发生改变。随着影像学技术的进展,三维可视化技术逐渐出现在医疗视野中,通过三维可视化技术与多层螺旋CT(multi-slice CT,MSCT)相结合,探究T2DM患者腺形态学改变的差异,有望弥补影像学检查对T2DM诊断的空白,同时评估T2DM患者的疾病进展。     

老年2型糖尿病患者25-羟基维生素D和血脂水平的分析

目的探讨老年2型糖尿病患者25-羟基维生素D(25-OH-VitD)、血脂水平的变化。方法对在我院住院的41例老年2型糖尿病患者和在门诊健康体检的48例正常老年人进行问卷调查、体格检查和生化指标等检测。结果老年2型糖尿病组的三酰甘油、低密度脂蛋白胆固醇水平明显高于对照组,25-OH-VitD、高密度脂蛋白胆固醇低于对照组;2型糖尿病组中25-OH-VitD低于正常值检出率、血脂异常检出率均高于对照组;25-OH-VitD低于正常值组2型糖尿病发生率高于正常值组。糖尿病发生率与25-OH-VitD、血脂异常均有相关性。结论老年2型糖尿病患者除严格控制血糖外,有必要检测25-OH-VitD、血脂水平,进行及早干预,以早期预防或延缓糖尿病并发症的出现,从而更好地改善生活质量。     

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.     

2型糖尿病患者血小板参数的检测及初步分析

目的通过对2型糖尿病患者的血液参数[血小板计数（PLT）、平均血小板体积（MPV）、血小板体积分布宽度（PDW）、大血小板比率（P-LCR）、血小板压积（PCT）]的调查分析，探讨糖尿病患者血小板参数变化与糖尿病的关系，以及糖尿病患者血小板变化的临床意义。方法选择2000～2006年我部30例2型糖尿病患者作为试验组。选50例年龄为50～72岁的老年人，排除有血液性疾病及其他代谢性疾病者作为对照组，分别采血3次，测血小板参数，包括血小板数（PLT）平均血小板体积（MPV）、血小板体积分布宽度（PDW）、血小板压积（PCT）、大血小板比率（P-LCR）。对所得结果行）χ^2检验。结果试验组与对照组比较，血小板参数变化差异有显著性（P〈0．05）。结论血小板参数变化在糖尿病的病程中对血管病变的发生、发展有重要作用，对临床研究糖尿病有较大参考价值。     

Atrial fibrillation is associated with increased mean platelet volume in patients with type 2 diabetes mellitus

Platelet abnormalities in diabetes mellitus (DM) and atrial fibrillation (AF) may underline the etiology of a prothrombotic state in these conditions. Increased mean platelet volume (MPV) is a marker of abnormal platelet function and activation. We aimed to investigate the possible association of chronic AF with MPV in patients who have type 2 DM. Patients who had type 2 DM with either chronic (≥6 months) AF or normal sinus rhythm (NSR) were included in the study. A total of 162 patients (aged 38–89 years) were divided into 2 groups according to the presence of either AF or NSR. Group 1 consisted of 81 diabetic patients with AF, and group 2 consisted of 81 diabetic patients with NSR. The two groups were not significantly different in terms of age, and gender, as well as in hypertension, smoking, history of coronary artery disease, previous cerebrovascular accidents, microalbuminuria, retinopathy, duration of DM, body mass index, hemoglobin A_1c, total cholesterol, low-density lipoprotein cholesterol, high-density lipoprotein cholesterol, and triglyceride (p?>?0.05 for all variables). Although no significant difference was present between groups concerning platelet count; for patients with AF, MPV was higher compared with patients with NSR (9.0?±?0.2?fl vs. 8.4?±?0.2?fl; p?=?0.001). Furthermore, no significant difference was noted between groups regarding routine medications received by patients. In multivariate logistic regression analysis, MPV was the only variable independently related to AF (OR?=?2.659; 95% CI, 1.286–5.498; p?=?0.008). Consequently, it is concluded that AF is associated with increased MPV in patients with type 2 DM, suggesting the presence of tentatively related processes leading to reciprocal interaction.     

Self-reported goals of older patients with type 2 diabetes mellitus

OBJECTIVES: New diabetes mellitus guidelines from the American Geriatrics Society promote the individualization of treatment goals and plans for patients aged 65 and older. Communicating with older patients about such complex medical decisions presents new challenges for providers. The self-reported healthcare goals, factors influencing these goals, and self-care practices of older patients with diabetes mellitus were explored. DESIGN: Exploratory study involving semistructured interviews. SETTING: Four clinics of a midwestern, urban academic medical center. PARTICIPANTS: Patients aged 65 and older with type II diabetes mellitus (N=28). MEASUREMENTS: Semistructured, one-on-one interviews were conducted. Interviews were audiotaped, transcribed, and evaluated for recurring themes using a grounded theory approach. RESULTS: The majority of patients expressed their healthcare goals in a social and functional language, in contrast to the biomedical language of risk factor control and complication prevention, even when specifically asked about goals for diabetes mellitus care. Patient's predominant healthcare goals centered on maintaining their independence and their activities of daily living (71%). Medical experiences of friends and family (50%), social comparison with peers (7%), and medical professionals (43%) shaped patients' goals. Self-reported medication adherence and glucose monitoring was high, but more than one-quarter of patients failed to adhere to any dietary recommendations, and one-third failed to adhere to their exercise regimens. CONCLUSION: As diabetes mellitus care recommendations for older patients grow more complex, providers could enhance their communication about such medical decisions by exploring patients' specific circumstances and reframing diabetes mellitus treatment goals in patients' own language. These may be crucial steps to developing successful individualized care plans.     

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.     

硝苯地平对糖尿病患者血小板聚集功能和胞质钙的影响

目的:探讨钙通道阻断剂硝苯地平对糖尿病患者血小板聚集(platelet aggregation,PAG)功能和血小板胞质游离钙(血小板[Ca2+ ]i)的作用.方法:用比浊法测定PAG,Fura-2荧光测钙技术测定血小板[Ca2+ ]i,观察硝苯地平对糖尿病患者 PAG和血小板[Ca2+ ]i的影响.结果:①糖尿病患者...     

Vitamin D and diabetes mellitus

Better understanding of the physiological role of the vitamin-D system, in particular its potential effects on inflammatory and autoimmune conditions as well as on insulin secretion and possibly also on insulin resistance, increased the interest in its potential role in prevention and control of the diabetic condition, both type-1 and -2 diabetes. Both these conditions are associated with inflammation and type-1 diabetes also with an autoimmune pathology. Indeed, animal and human studies support the notion that adequate vitamin-D supplementation may decrease the incidence of type-1 and possibly also of type-2 diabetes mellitus and may improve the metabolic control in the diabetes state. However, the exact mechanisms by which vitamin-D and calcium supplementation exert their beneficial effects are not clear and need further investigation.     

妊娠糖尿病:产后管理减少发生2型糖尿病的风险

妊娠糖尿病(GDM)不仅增加围产期孕妇和胎儿患病的风险,而且增加孕妇产后发生2型糖尿病(T2DM)的风险.GDM发展为T2DM有很多危险因素,关键是重视对GDM妇女产后随访和血糖的筛查,以及产后的各种干预措施如健康的生活方式、母乳喂养和必要时药物干预.这对减少Tr2DM发生的风险有重要意义.