Vitamin D levels and asymptomatic coronary artery disease in type 2 diabetic patients with elevated urinary albumin excretion rate

Serum 25(OH)D Concentration and Cardiovascular Disease Risk Markers Among Middle-Aged Healthy and Type 2 Diabetic Subjects

Vitamin D deficiency is a major widespread health concern and is linked to a high risk of cardiovascular disease (CVD). Thus, we have investigated the association of vitamin D with various CVD risk markers. The present study comprises 90 control and 90 type 2 diabetes mellitus (T2DM) subjects of both sexes (age range, 30-50 years). The 25 hydroxyvitamin D [25(OH)D] and CVD risk markers including high sensitive C-reactive protein (hs-CRP), monocyte chemoattractant protein-1 (MCP-1), intact parathyroid hormone (I-PTH), fibroblast growth factor (FGF)-23, erythrocyte sedimentation rate (ESR), and fibrinogen were measured by using standard assays. Blood viscosity and atherogenic index of plasma calculated using standard formulae. The ten-year cardiovascular risk was assessed using the Framingham risk score (FRS). 25(OH)D, hs-CRP, MCP-1, FGF-23, ESR, fibrinogen, atherogenic index of plasma and FRS were significantly different between control and T2DM groups (p<0.05). 25(OH)D showed a significant negative correlation with MCP-1, ESR, blood viscosity, atherogenic index of plasma and FRS among total study subjects. Further, logistics regression analysis showed an association of 25(OH)D with MCP-1, hematocrit, fibrinogen, and blood viscosity. The association between 25(OH)D and various CVD risk markers suggests that 25(OH)D might help in the prediction of CVD risk.

Association of Serum 25-Hydroxyvitamin D Concentrations With All-Cause and Cause-Specific Mortality Among Individuals With Diabetes

OBJECTIVE

The evidence regarding vitamin D status and mortality among people with diabetes is scarce. This study aimed to examine the association of serum 25-hydroxyvitamin D [25(OH)D] concentrations with all-cause and cause-specific mortality among adults with diabetes.

RESEARCH DESIGN AND METHODS

This study included 6,329 adults with diabetes from the Third National Health and Nutrition Examination Survey (NHANES III) and NHANES 2001-2014. Death outcomes were ascertained by linkage to National Death Index records through 31 December 2015. Cox proportional hazards models were used to estimate hazard ratios (HR) and 95% CIs for mortality from all causes, cardiovascular disease (CVD), and cancer.

RESULTS

The weighted mean (95% CI) level of serum 25(OH)D was 57.7 (56.6, 58.8) nmol/L, and 46.6% had deficient vitamin D (<50 nmol/L [20 ng/mL]). Higher serum 25(OH)D levels were significantly associated with lower levels of glucose, insulin, HOMA of insulin resistance, HbA_1c, blood lipids, and C-reactive protein at baseline (all P _trend < 0.05). During 55,126 person-years of follow-up, 2,056 deaths were documented, including 605 CVD deaths and 309 cancer deaths. After multivariate adjustment, higher serum 25(OH)D levels were significantly and linearly associated with lower all-cause and CVD mortality: there was a 31% reduced risk of all-cause mortality and a 38% reduced risk of CVD mortality per one-unit increment in natural log-transformed 25(OH)D (both P < 0.001). Compared with participants with 25(OH)D <25 nmol/L, the multivariate-adjusted HRs and 95% CI for participants with 25(OH)D >75 nmol/L were 0.59 (0.43, 0.83) for all-cause mortality (P _trend = 0.003), 0.50 (0.29, 0.86) for CVD mortality (P _trend = 0.02), and 0.49 (0.23, 1.04) for cancer mortality (P _trend = 0.12).

CONCLUSIONS

Higher serum 25(OH)D levels were significantly associated with lower all-cause and CVD mortality. These findings suggest that maintaining adequate vitamin D status may lower mortality risk in individuals with diabetes.

The role of vitamin D in the pathogenesis and treatment of diabetes mellitus: a narrative review

Diabetes mellitus, a metabolic disorder associated with chronic complications, is traditionally classified into two main subtypes. Type 1 diabetes mellitus (T1DM) results from gradual pancreatic islet β cell autoimmune destruction, extending over months or years. Type 2 diabetes mellitus (T2DM) is a heterogeneous disorder, with both insulin resistance and impairment in insulin secretion contributing to its pathogenesis. Vitamin D is a fat-soluble vitamin with an established role in calcium metabolism. Recently, several studies have provided evidence suggesting a role for it in various non-skeletal metabolic conditions, including both types of diabetes mellitus. Preclinical studies of vitamin D action on insulin secretion, insulin action, inflammatory processes, and immune regulation, along with evidence of an increase of hypovitaminosis D worldwide, have prompted several epidemiological, observational, and supplementation clinical studies investigating a potential biological interaction between hypovitaminosis D and diabetes. This narrative review aims to summarize current knowledge on the effect of vitamin D on T1DM and T2DM pathogenesis, prevention, and treatment, as well as on micro- and macrovascular complications of the disease. Furthermore, on the basis of current existing evidence, we aim to highlight areas for potential future research.

Non-traditional risk factors for coronary calcification and its progression in patients with type 2 diabetes: The impact of postprandial glycemia and fetuin-A

Objective

This study was performed to assess the impact of risk factors on the presence and progression of coronary calcification in patients with type 2 diabetes.

Methods

We prospectively enrolled 45 patients without cardiovascular or kidney disease. Coronary calcification was measured with multidetector computed tomography at baseline and 18 months. We also measured blood pressure; body mass index; serum levels of calcium, phosphate, and 25-hydroxyvitamin D; mineral bone density; and levels of alkaline phosphatase, parathormone, fetuin-A, high-sensitivity C-reactive protein, fibrinogen, albumin, homocysteine, lipids, HbA1c, and average preprandial and postprandial blood glucose at 18 months. Information about severe hypoglycemia and smoking was recorded. Spearman’s correlation coefficients were calculated. Multiple linear regression was used for the multivariate analysis.

Results

The median baseline calcium score was 63, and that at 18 months was 100. In the univariate analysis, albumin was significantly correlated with the baseline calcium score. Fetuin-A and postprandial glycemia were correlated with calcium score progression. In the multivariate model, postprandial glycemia and fetuin-A were independently associated with calcium score progression.

Conclusions

Fetuin-A and postprandial glycemia influence coronary calcification progression in patients with type 2 diabetes. The absence of some correlations could be due to pharmacological treatments for cardiovascular risk reduction.

Correlation between coronary artery calcification by non-cardiac CT and Framingham score in young patients

Background

Previous studies have established a correlation between coronary artery calcification (CAC) measured by ECG-gated chest computed tomography (CT) and cardiovascular disease. Recent reports which included asymptomatic patients suggest that CAC measured on non-ECG gated CT is similarly associated with cardiovascular risk. This study investigates the correlation between the Framingham Risk Score (FRS) and an incidental finding of CAC on a non-gated chest CT performed for non-cardiac indications in young and seemingly healthy adults.

Methods

A cross-sectional study that included 162 CT scans performed in young patients aged 18–50 years old for non-cardiac indications in our institution was conducted. CAC score (CACS) was calculated using the Agatston method. FRS was calculated and compared to the CACS using three different approaches. The correlations between the CACS and several specific factors (i.e. age, body mass index, smoking, statins, etc.), were also evaluated.

Results

Mean age of patients was 36.43 year old and 105 (64.8%) were male. We found a significant positive correlation between the CACS and the FRS in all three approaches (p<0.05). Increased age, smoking and statin use were the only individual factors clearly associated with an increase in CACS (p = 0.002, p = 0.045 and p = 0.009, respectively).

Conclusion

This is the first report indicating that incidental CACS identified in non-gated MDCT is also associated with cardiovascular risk evaluated by FRS in a young population. Our findings suggest that young asymptomatic individuals with incidental CAC should be seriously evaluated for cardiovascular risk factors despite presumption of belonging to a low cardiovascular risk category.

Association of Vitamin D Deficiency and Degree of Coronary Artery Disease in Cardiac Patients with Type 2 Diabetes

Several modifiable factors may influence cardiac function in diabetic patients. The aim of the study was to evaluate the influence of vitamin D level on the stage of coronary atherosclerosis in cardiac patients diagnosed with type 2 diabetes. The study was performed in 337 consecutive patients undergoing coronarography. The stage of atherosclerosis was evaluated using Coronary Artery Surgery Study Score. The plasma 25(OH)D concentration was determined by an electrochemiluminescence method. Patients without significant lesions in coronary arteries presented the highest 25(OH)D level, significantly higher than patients with one-, two-, and three-vessel coronary artery disease (CAD) (p < 0.01). Significantly lower level of the 25(OH)D was observed in patients hospitalized due to acute coronary syndrome (ACS) in comparison to patients hospitalized due to stable CAD (p < 0.001). Lower 25(OH)D levels were observed in patients with the history of myocardial infarction (MI) in comparison to patients without previous MI (p < 0.001). In cardiac patients with diabetes, the higher number of stenotic coronary arteries is associated with lower values of the 25(OH)D. A group of male cardiac patients with diabetes with significant stenosis in three coronary arteries, hospitalized due to acute coronary syndrome, with a history of previous MI and hyperlipidemia presented the lowest vitamin D level.

Is there any association between vitamin D levels and isolated coronary artery ectasia?

Introduction

It has been postulated that low vitamin D levels are associated with coronary artery diseases. Coronary artery ectasia (CAE) is associated with atherosclerosis, congenital cardiac defects, immunological diseases and connective tissue diseases. In this study, we aimed to investigate whether there is an association between vitamin D and parathormone levels and isolated coronary artery ectasia and its extent.

Material and methods

The study included 93 participants: 47 patients (35 male, 12 female) with isolated CAE and 46 subjects (28 male, 18 female) with normal coronary arteries. Demographic characteristics of patients and controls were obtained from medical records, and Markis scores of patients were calculated. Serum vitamin D and parathormone levels were quantitatively measured by the paramagnetic particle chemiluminescence method.

Results

Serum vitamin D levels were found to be significantly lower in patients with isolated CAE than the control group (9.15 ±4.4 ng/ml, 13.35 ±5.9 ng/ml, p < 0.001). Parathormone levels were significantly higher in the CAE group than the control group (61.4 ±31.6, 48.7 ±25.5, p < 0.036). However, the study revealed no association between serum vitamin D levels and the extent of CAE according to the Markis classification (p = 0.23).

Conclusions

This study revealed that lower vitamin D levels and higher parathormone levels were associated with isolated CAE, but there was no association between vitamin D levels and the extent of CAE.

Refining Long-Term Prediction of Cardiovascular Risk in Diabetes - The VILDIA Score

Cardiovascular risk assessment in patients with diabetes relies on traditional risk factors. However, numerous novel biomarkers have been found to be independent predictors of cardiovascular disease, which might significantly improve risk prediction in diabetic patients. We aimed to improve prediction of cardiovascular risk in diabetic patients by investigating 135 evolving biomarkers. Based on selected biomarkers a clinically applicable prediction algorithm for long-term cardiovascular mortality was designed. We prospectively enrolled 864 diabetic patients of the LUdwigshafen RIsk and Cardiovascular health (LURIC) study with a median follow-up of 9.6 years. Independent risk factors were selected using bootstrapping based on a Cox regression analysis. The following seven variables were selected for the final multivariate model: NT-proBNP, age, male sex, renin, diabetes duration, Lp-PLA2 and 25-OH vitamin D3. The risk score based on the aforementioned variables demonstrated an excellent discriminatory power for 10-year cardiovascular survival with a C-statistic of 0.76 (P < 0.001), which was significantly better than the established UKPDS risk engine (C-statistic = 0.64, P < 0.001). Net reclassification confirmed a significant improvement of individual risk prediction by 22% (95% confidence interval: 14–30%) compared to the UKPDS risk engine (P < 0.001). The VILDIA score based on traditional cardiovascular risk factors and reinforced with novel biomarkers outperforms previous risk algorithms.

Vitamin-D concentrations, cardiovascular risk and events - a review of epidemiological evidence

Vitamin D has long been established as an elemental factor of bone physiology. Beyond mineral metabolism, the expression of the vitamin D receptor has been identified throughout the cardiovascular (CV) system. Experimental studies showed beneficial effects of vitamin D on heart and vessels, but vitamin D intoxication in animals also led to hypercalcemia and vascular calcification. Our knowledge has been extended by epidemiological studies that showed that 25-hydroxyvitamin D (25(OH)D) levels are inversely associated with an increased CV risk itself, but also with established CV risk factors, such as arterial hypertension, endothelial dysfunction and atherosclerosis. Conversely, randomized controlled trials could not document significant and consistent effects of vitamin D supplementation on CV risk or events. Potential explanations may lie in differences in reference ranges or the possibility that low vitamin D in CV disease is only an epiphenomenon. In the latter case, the key question is why low 25(OH)D levels are such a strong predictor of health. While we wait for new data, the current conclusion is that vitamin D is a strong risk marker for CV risk factors and for CV diseases itself.

Vitamin D and diabetes mellitus: Causal or casual association?

The incidence of both type 2 and type 1 diabetes mellitus has been increasing worldwide. Vitamin D deficiency, or the awareness of its prevalence, has also been increasing. Vitamin D may have a role in the pathogenic mechanisms predisposing to type 2 diabetes by modulating insulin resistance and/or pancreatic β-cell function. Vitamin D status or elements involved in its activation or transport may also be involved in the development of type 1 diabetes mellitus through immunomodulatory role . Based on these observations a potential association between vitamin D and diabetes has been hypothesized. In this review we discuss up to date evidence linking vitamin D with the development of diabetes. Moreover, the role of vitamin D supplementation in the prevention of both types of diabetes is analysed together with its role in improving glycemic control in diabetic patients. We also address the potential role of vitamin D deficiency in the development of macro- and microvascular complications in diabetes. Finally, we provide recommendation for Vitamin D therapy in diabetes in view of current evidence and highlight areas for potential future research in this area.

Dysfunctional immunometabolic effects of vitamin D deficiency, increased cardiometabolic risk. Potential epidemiological alert in America?

Vitamin D deficiency is a serious public health problem worldwide that affects not only skeletal health, but also a wide range of acute and chronic diseases. However, there is still skepticism because of the lack of randomized, controlled trials to support association studies on the benefits of vitamin D for non-skeletal health. This review was based on articles published during the 1980-2015 obtained from the Cochrane Central Register of controlled trials, MEDLINE and PubMed, and focuses on recent challenges with regard to the definition of vitamin D deficiency and how to achieve optimal serum 25-hydroxyvitamin D levels from dietary sources, supplements, and sun exposure. The effect of vitamin D on epigenetic fetal programming and regulation of genes that may potentially explain why vitamin D could have such lifelong comprehensive health benefits is reviewed. Optimization of vitamin D levels in children and adults around the world has potential benefits to improve skeletal health and to reduce the risk of chronic diseases, including some types of cancer, autoimmune diseases, infectious diseases, type 2 diabetes mellitus, and severe cardiovascular disorders such as atherothrombosis, neurocognitive disorders, and mortality.

Lower Vitamin D Metabolites Levels Were Associated With Increased Coronary Artery Diseases in Type 2 Diabetes Patients in India

The purpose of the present study was to measure six vitamin D metabolites and to find the association between vitamin D deficiency and coronary artery diseases in diabetes (T2DM_CAD). Four groups [control (n = 50), type 2 diabetes (T2DM, n = 71), coronary artery diseases (CAD, n = 28), T2DM_CAD (n = 38)] of total 187 subjects were included in the study. Six vitamin D metabolites (D₂, D₃, 25(OH)D₂, 25(OH)D₃, 1,25(OH)₂D₂, 1,25(OH)₂D₃), total 25(OH)D and total 1,25(OH)₂D were measured by UPLC/APCI/HRMS method in these subjects. Although all the vitamin D metabolites were significantly decreased in T2DM_CAD as compared to both control and T2DM subjects (p < 0.05), only two metabolites i.e., 25(OH)D₃ and total 25(OH)D were significantly (p < 0.05) decreased in the T2DM subjects as compared with the control subjects (p < 0.05). Vitamin D₃, 1,25(OH)₂D₂, 25(OH)D, and 1,25(OH)₂D levels were significantly decreased in T2DM_CAD subjects as compared with CAD subjects (p < 0.05). Further, multiple logistic regression analysis revealed that total 25(OH)D and total 1,25(OH)₂D can be used to predict T2DM (OR 0.82.95% CI 0.68-0.99; p = 0.0208) and T2DM with CAD (OR 0.460, 95% CI 0.242-0.874; p = 0.0177), respectively. Our data concludes that lower concentration of 1,25(OH)₂D is associated with type 2 diabetes coexisting with coronary artery diseases in South Indian subjects.

Vitamin D and its effects on cardiovascular diseases: a comprehensive review

Vitamin D is a molecule that is actively involved in multiple metabolic pathways. It is mostly known for its implications related to calcium metabolism. It has also been determined that it actively participates in the cardiovascular system, influencing blood pressure, coronary artery disease and other vascular diseases, such as heart failure and atrial fibrillation. Furthermore, it has been established that this vitamin is extensively involved in the regulation of both the renin angiotensin aldosterone system and the immune system. In this review, we present the different vitamin D metabolic pathways associated with the cardiovascular pathophysiology, and we include studies in animal and human models, as well as some of the controversies found in the literature. This review also incorporates an overview of the implications in the molecular biology and public health fields.

Vitamin D Deficiency Is Associated with Severity of Acute Coronary Syndrome in Patients with Type 2 Diabetes and High Rates of Sun Exposure

BACKGROUND

Vitamin D deficiency has been associated with cardiovascular risk factors, including type 2 diabetes mellitus (T2DM). Evidence shows that patients with low serum 25-hydroxyvitamin D (25OHD) concentrations have a higher risk of developing coronary artery disease.

OBJECTIVE

The objective of this study was to assess vitamin D as a predictor of the severity in diabetics with acute coronary syndrome (ACS).

METHODS

A total of 166 patients were diagnosed with ACS. Serum 25OHD concentrations were analyzed, and risk factors for ACS were evaluated.

RESULTS

Patients diagnosed as having acute myocardial infarction with elevation of the ST segment had a higher rate of 25OHD, <20 ng/mL compared to ≥30 ng/mL (47.8% × 13.4%, P = 0.03). Diabetics with vitamin D deficiency had more multivessel lesions in the coronary angiography than non-diabetics (69% × 31.8%, P = 0.007). After adjustments for confounders, serum 25OHD remained associated with more severe disease.

CONCLUSION

Vitamin D deficiency is associated with more severe ACS and is a predictor of more extensive coronary lesions in patients with T2DM.

A Significant Positive Association of Vitamin D Deficiency with Coronary Artery Calcification among Middle-aged Men: For the ERA JUMP Study

OBJECTIVE

Although a significant positive association of vitamin D deficiency with coronary heart disease has been demonstrated in cross-sectional as well as prospective studies, only a few studies have examined the association of vitamin D deficiency with subclinical atherosclerosis. We examined whether vitamin D deficiency is associated with subclinical atherosclerosis, as measured by coronary artery calcification (CAC) in asymptomatic adults.

METHODS

In a population-based cross-sectional study, 195 men aged 40 to 49 years without cardiovascular disease were randomly selected (98 Caucasian and 97 Japanese American men). Liquid chromatography-tandem mass spectrometry was utilized to measure serum vitamin D. CAC was examined by electron beam computed tomography using standardized protocols and read centrally at the University of Pittsburgh using Agatston's methods. To investigate an association between vitamin D deficiency (defined as 25-hydroxyvitamin D [25(OH)D] < 20 ng/mL) and CAC (defined as Agatston score ≥ 10), we utilized multivariable logistic regression models.

RESULTS

Prevalence of CAC and vitamin D deficiency was 27.2% and 10.3%, respectively. Participants with CAC were significantly older, had significantly higher body mass index (BMI), and had higher rates of smoking. Those with CAC were 3.31 times likely to be vitamin D deficient, after adjusting for traditional cardiovascular risk factors (odds ratio [OR] = 3.31, 95% confidence interval [CI], 1.12-9.77).

CONCLUSIONS

In this population-based study of healthy middle-aged men, vitamin D deficiency had a significant positive association with the presence of CAC.

Low 25-OH vitamin D levels are not associated with coronary artery calcium or obstructive stenoses

BACKGROUND

It is unclear whether low vitamin D is a significant risk factor for the presence of either calcific atherosclerosis or obstructive coronary artery stenoses.

DESIGN

In this study, we measured the 25-OH vitamin D levels of 1131 consecutive individuals who underwent coronary artery calcium (CAC) scoring and coronary computed tomographic angiography at our institution.

PARTICIPANTS AND METHODS

We looked for any association of 25-OH vitamin D levels with CAC scores. We also studied the relation of 25-OH vitamin D levels with the presence of 70% or more obstructive coronary artery stenoses, found initially by coronary computed tomographic angiography and confirmed subsequently by invasive angiography.

RESULTS

There were 132 (11.7%) 25-OH vitamin D deficient (<20 ng/ml) and 295 (26.1%) 25-OH vitamin D insufficient (21-29 ng/ml) individuals in this study. There was no detectable association between 25-OH vitamin D levels and CAC scores. The median (interquartile range) CAC score of 25-OH vitamin D deficient, insufficient, and adequate patients was 451 (80-1083), 338 (52-830), and 450 (100-1062), respectively. Also, no relation was noted between 25-OH vitamin D levels and the presence of severely obstructive coronary artery disease. The frequency of severe coronary artery disease in 25-OH vitamin D deficient, insufficient, and adequate patients was 3.8, 2.0, and 4.0%, respectively.

CONCLUSION

Low 25-OH vitamin D levels were not associated with CAC or severely obstructive stenoses.

Interplay of vitamin D and metabolic syndrome: A review

Vitamin D deficiency is a worldwide public health problem. Vitamin D deficiency plays key role in the pathophysiology of risk factors of metabolic syndrome which affect cardiovascular system, increase insulin resistance and obesity, stimulate rennin-angiotensin-aldosterone system that cause hypertension. The discovery of vitamin D receptor expressed ubiquitously in almost all body cells such as immune, vascular and myocardial cells, pancreatic beta cells, neurons and osteoblasts suggests an involvement of vitamin D mediated effects on metabolic syndrome. Moreover vitamin D deficiency as well as cardiovascular diseases and related risk factors frequently co-occur. This underlines the importance of understanding the role of vitamin D in the context of metabolic syndrome. The paper provides an insight into the physiology of vitamin D and relationship of vitamin D deficiency with risk factors of metabolic syndrome through observational and supplementation studies.

Hypovitaminosis D: a novel risk factor for coronary heart disease in type 2 diabetes?

Vitamin D (25(OH)D) levels have been associated with cardiovascular disease. Thus, the aim of our study was to investigate the association of 25(OH)D levels with coronary heart disease (CHD) in 698 consecutive type 2 diabetic outpatients. 698 consecutive type 2 diabetic outpatients (25.2 % men, age 66 ± 9 years) and 100 (90 % men, age 65 ± 13 years) age-matched non-diabetic volunteers were enrolled. 25(OH)D assay and the main cardiovascular risk factors were explored. 25(OH)D concentration was 22 ± 10 ng/ml in control subjects and 18.23 ± 10 ng/ml in diabetic patients (p < 0.01). The prevalence of hypovitaminosis D was higher in diabetic patients than in control subjects (90 vs. 83 %, p < 0.01). Diabetic subjects with hypovitaminosis D had higher prevalence of high values of A1C (p < 0.01), BMI (p < 0.01), LDL cholesterol (p < 0.01), triglycerides (p < 0.01), and glycemia (p < 0.01) than their vitamin D-sufficient counterparts. 25(OH)D and HDL cholesterol were lower (p < 0.01), while BMI (p < 0.01), age (p < 0.01), systolic (p < 0.01) and diastolic blood pressure (p < 0.01), diabetes duration (p < 0.01), A1C (p < 0.01), glycemia (p < 0.01), fibrinogen (p < 0.01), triglycerides (p < 0.01), and total (p < 0.01) and LDL cholesterol (p < 0.01) were higher in diabetic subjects with CHD than diabetic subjects without CHD. At the logistic regression analysis, the association of vitamin D with CHD was lost, while sex (p = 0.026), diabetes duration (p = 0.023), and age (p = 0.024) were the most powerful predictors of CHD. The current study demonstrates that 25(OH)D does not have a direct effect on CHD but may have an indirect effect mediated by cardiovascular risk factors such as diabetes duration, age, and sex.

Assessment of serum 25-hydroxy vitamin D improves coronary heart disease risk stratification in patients with type 2 diabetes

BACKGROUND

A growing body of evidence suggests an association between lower serum 25-hydroxy vitamin D (25(OH)VitD) levels and adverse cardiovascular events. Patients with type 2 diabetes mellitus (T2DM) are at increased risk for developing coronary heart disease (CHD). 25-Hydroxy vitamin D deficiency is highly prevalent, especially among patients with T2DM. This study aimed to evaluate the predictive value of serum 25(OH)VitD in improvement of CHD risk stratification in patients with T2DM.

METHODS

In an open cohort, community-dwelling T2DM patients were followed up for first CHD event. Patients were divided into 4 categories, based on 25(OH)VitD quartiles. Cox regression analysis was used to obtain hazard ratios.

RESULTS

A total number of 2,607 T2DM patients were followed up for median time of 8.5 years. During follow-up, 299 patients experienced CHD events. Patients in the lowest quartile experienced more CHD events. Adjusted hazard ratios (95% CI) for developing CHD events were 0.77 (0.55-1.07) for second quartile, 0.52 (0.38-0.73) for third quartile, and 0.43 (0.31-0.60) for fourth quartile, compared with the first quartile. The incidence rate decreased as serum 25(OH)VitD increased, which remained significant after stepwise adjustments (P value for trend ≤.001). Addition of 25(OH)VitD to traditional risk factors in Framingham Risk Score successfully reclassified 29% of study population.

CONCLUSIONS

Serum 25(OH)VitD is an independent predictor of future adverse CHD events in patients with T2DM. Addition of 25(OH)VitD status to Framingham Risk Score improves CHD risk prediction in patients with T2DM.

High prevalence of vitamin D deficiency and lack of association with subclinical atherosclerosis in asymptomatic patients with Type 1 Diabetes Mellitus from a Mediterranean area

AIMS

Several studies linked vitamin D deficiency with coronary artery disease (CAD). The aim of this study was to evaluate the relationship between the concentrations of 25-hydroxyvitamin D (25OHD) and the presence of early atherosclerosis in asymptomatic Type 1 Diabetes (T1D) patients with no previous history of ischemic heart disease.

METHODS

One hundred and forty-five patients with T1D (age 37.8 ± 8 years, 57 % male, all Caucasian, disease duration 20.6 ± 8.3 years, HbA1c 7.6 ± 1.4 % (60.2 ± 11.1 mmol/mol), body mass index (BMI) 25.2 ± 3.5 kg/m2, 52.4 % smokers, 23 % retinopathy, 10 % nephropathy) and 48 controls matched for age, sex, BMI and smoking habit were studied. 25OHD deficiency was defined for values ≤20 ng/mL. A sun exposure questionnaire, carotid ultrasonography to determine carotid intima-media thickness (CIMT) and the presence of atheroma plaques and cardiac computed tomography for evaluation of calcium artery calcification (CACS) were performed.

RESULTS

T1D subjects showed a high proportion of 25OHD deficiency (43.2 % vs. 21.7 %, p = 0.032). Of all, 82 % of T1D patients and 92 % of controls had a calcium score of 0. CIMT was greater in patients with T1D (0.55 ± 0.14 mm vs 0.48 ± 0.15, p = 0.01) compared with controls. T1D subjects showed no differences in the results of CACS or CIMT according to the vitamin D concentrations.

CONCLUSIONS

T1D patients have lower concentrations and twice more prevalence of 25OHD deficiency than controls. There was no association between 25OHD concentrations and subclinical CAD.

Vitamin D & its analogues in type 2 diabetic nephropathy: a systematic review

Nephropathy is one of the major complications of diabetes often leading to chronic kidney disease (CKD). Inflammation and oxidative stress are associated with pathogenesis of diabetic nephropathy (DN) and found to be regulated by nuclear receptors such as vitamin D receptors (VDR). Vitamin D and its analogues have been effectively used in patients with CKD. The review attempts to summarize the available evidence on the role of vitamin D in DN. Electronic databases (MEDLINE, EMBASE, and Cochrane Library) were searched for studies assessing the role of vitamin D or its analogues on kidney function in type 2 diabetic patients. Studies evaluating kidney functions (urinary albumin/protein creatinine ratio, albuminuria and eGFR) were included and quality and risk of bias assessment performed. Additionally effect on 25 (OH) vitamin D, calcium and HbA1c were evaluated. The mean or its % change along with their standard deviation (SD) was used for reporting our results. RevMan (V5.2) was used for data analysis. Six studies included in this review evaluated the role of cholecalciferol, calcitriol and paricalcitol in patients with DN. Study designs differed (three randomized, one non-randomized and two uncontrolled trials) with varying degree of quality and risk of biases. Vitamin D analogues showed significant improvement in kidney function in two randomized studies. None of the studies reported significant incidences of hypercalcemia. Vitamin D analogues show significant improvement of kidney function in DN. Randomized controlled trials with longer duration, comparing the efficacy of vitamin D and its analogues are needed.

Vitamin D, carotid intima-media thickness and bone structure in patients with type 2 diabetes

Despite aggressive treatment of cardiovascular disease (CVD) risk factors individuals with type 2 diabetes (T2D) still have increased risk of cardiovascular morbidity and mortality. The primary aim of this study was to examine the cross-sectional association between total (25-hydroxy vitamin D (25(OH)D)) and risk of CVD in patients with T2D. Secondary objective was to examine the association between 25(OH)D and bone health. A Danish cohort of patients with T2D participating in a randomised clinical trial were analysed. In total 415 patients (68% men, age 60±9 years (mean±s.d.), duration of diabetes 12±6 years), including 294 patients (71%) treated with insulin. Carotid intima-media thickness (IMT) and arterial stiffness (carotid artery distensibility coefficient (DC) and Young's elastic modulus (YEM)) were measured by ultrasound scan as indicators of CVD. Bone health was assessed by bone mineral density and trabecular bone score measured by dual energy X-ray absorptiometry. In this cohort, 214 patients (52%) were vitamin D deficient (25(OH)D <50 nmol/l). Carotid IMT was 0.793±0.137 mm, DC was 0.0030±0.001 mmHg, YEM was 2354±1038 mmHg and 13 (3%) of the patients were diagnosed with osteoporosis. A 25(OH)D level was not associated with carotid IMT or arterial stiffness (P>0.3) or bone health (P>0.6) after adjustment for CVD risk factors. In conclusion, 25(OH)D status was not associated with carotid IMT, arterial stiffness or bone health in this cohort of patients with T2D. To explore these associations and the association with other biomarkers further, multicentre studies with large numbers of patients are required.

Vitamin D analogue therapy, cardiovascular risk and kidney function in people with Type 1 diabetes mellitus and diabetic nephropathy: a randomized trial

AIM

To evaluate the effects of therapy with the vitamin D analogue paricalcitol on markers of cardiovascular risk and kidney function in people with Type 1 diabetes mellitus and diabetic nephropathy.

METHODS

In a double-blind, randomized placebo-controlled, crossover trial, 48 participants on stable renin angiotensin aldosterone system blockade and diuretics were assigned, in random order, to 12 weeks of paricalcitol and 12 weeks of placebo therapy, separated by a 4-week washout period. Primary and secondary endpoints were changes in plasma N-terminal probrain natriuretic peptide and urinary albumin excretion rate obtained before and after each intervention. Glomerular filtration rates were estimated and measured ((51) Cr-EDTA plasma clearance glomerular filtration rate) after each intervention.

RESULTS

The mean (sd) age of the participants was 57 (9) years, the baseline geometric mean (95% CI) urinary albumin excretion rate was 148 (85-259) mg/24 h, the mean (sd) HbA1c was 70 (9) mmol/mol [8.6 (3)%], the mean (sd) estimated glomerular filtration rate was 47 (15) ml/min/1.73 m(2) and the mean (sd) 24-h blood pressure was 135 (17)/74 (10) mmHg. Compared with placebo therapy, vitamin D analogue therapy had no significant effect on plasma N-terminal probrain natriuretic peptide concentration (P = 0.6), urinary albumin excretion rate was reduced by 18% (P = 0.03 for comparison), estimated glomerular filtration rate was reduced by 5 ml/min/1.73 m(2) (P < 0.001) and measured glomerular filtration rate was reduced by 1.5 ml/min/1.73 m(2) (P = 0.2).

CONCLUSIONS

Paricalcitol therapy did not affect plasma N-terminal probrain natriuretic peptide concentration in people with Type 1 diabetes and diabetic nephropathy; however, the urinary albumin excretion rate was significantly lowered.

Vitamin D Deficiency Is Associated with the Presence and Severity of Diabetic Retinopathy in Type 2 Diabetes Mellitus

There is very few evidences on the role of vitamin D in the development of diabetic retinopathy. The aim of the current study was to explore whether there is an association of vitamin D status and diabetic retinopathy in type 2 diabetes. Two groups of patients were selected: 139 and 144 patients with and without retinopathy, respectively, as assessed by an experienced ophthalmologist. Subjects with advanced late diabetic complications were excluded to avoid confounding biases. 25-Hydroxy-vitamin D3 (25(OH)D) concentrations and vitamin D deficiency were associated with the presence of diabetic retinopathy. Additionally, patients with more advanced stages of retinopathy (grades 2-4) had lower concentrations of 25(OH)D and were more frequently vitamin D deficient as compared with patients not carrying this eye complication. In conclusion, our study confirms the association of vitamin D deficiency with the presence and severity of diabetic retinopathy in type 2 diabetes. Further experimental and prospective studies on this issue are clearly warranted.

The Effects of Vitamin D Supplementation on Glucose Control and Insulin Resistance in Patients with Diabetes Type 2: A Randomized Clinical Trial Study

BACKGROUND

Vitamin D deficiency is prevalent in diabetes type 2 and this vitamin may be related to insulin action. This randomized controlled trial study was done to evaluate the effect of vitamin D supplementation on glucose control and insulin resistance in patients with diabetes type 2.

METHODS

Participants of this randomized clinical trial study consisted of 28 patients with type 2 diabetes who received 100 microgram (4000 IU) vitamin D and 30 diabetic patients who received placebo for 2 months between September 2012 and February 2013. The effect of vitamin D on glucose control was assessed by measuring HbA1c and insulin resistance as HOMA-IR at the baseline and the end of the intervention.

RESULTS

The results showed a significant decrease in HbA1c (from 7.29 ± 0.22 % to 6.76 ± 0.18 %, P<0.001) and insulin concentration (from 8.24 ± 0.97 μIU/mL to 6.55 ± 0.28 μIU/mL, P=0.048), but a non-significant decrease in HOMA-IR in vitamin D group. Also, HDL-C level increased significantly in both of vitamin D (P=0.046) and placebo groups (P=0.028).

CONCLUSION

It seems that vitamin D supplementation has beneficial effects on glucose homeostasis and can increases insulin sensitivity in diabetic 2 patients.

Type 2 diabetes and cardiovascular disease: Have all risk factors the same strength?

Diabetes mellitus is a chronic condition that occurs when the body cannot produce enough or effectively use of insulin. Compared with individuals without diabetes, patients with type 2 diabetes mellitus have a considerably higher risk of cardiovascular morbidity and mortality, and are disproportionately affected by cardiovascular disease. Most of this excess risk is it associated with an augmented prevalence of well-known risk factors such as hypertension, dyslipidaemia and obesity in these patients. However the improved cardiovascular disease in type 2 diabetes mellitus patients can not be attributed solely to the higher prevalence of traditional risk factors. Therefore other non-traditional risk factors may be important in people with type 2 diabetes mellitus. Cardiovascular disease is increased in type 2 diabetes mellitus subjects due to a complex combination of various traditional and non-traditional risk factors that have an important role to play in the beginning and the evolution of atherosclerosis over its long natural history from endothelial function to clinical events. Many of these risk factors could be common history for both diabetes mellitus and cardiovascular disease, reinforcing the postulate that both disorders come independently from “common soil”. The objective of this review is to highlight the weight of traditional and non-traditional risk factors for cardiovascular disease in the setting of type 2 diabetes mellitus and discuss their position in the pathogenesis of the excess cardiovascular disease mortality and morbidity in these patients.

Vitamin D deficiency and coronary artery disease: a review of the evidence

Coronary artery disease remains the leading cause of death in developed countries despite significant progress in primary prevention and treatment strategies. Older patients are at particularly high risk of poor outcomes following acute coronary syndrome and impaired nutrition, including low vitamin D levels, may play a role. The extraskeletal effects of vitamin D, in particular, its role in maintaining a healthy cardiovascular system are receiving increased attention. Longitudinal studies have demonstrated increased cardiovascular mortality and morbidity associated with vitamin D deficiency. Low vitamin D levels have been linked to inflammation, higher coronary artery calcium scores, impaired endothelial function and increased vascular stiffness. However, so far, few randomized controlled trials have investigated the potential benefits of vitamin D supplementation in preventing cardiovascular events, and most available trials have tested low doses of supplementation in relatively low-risk populations. Whether vitamin D supplementation will be beneficial among patients with coronary artery disease, including high risk older patients presenting with acute coronary syndrome, is unknown and warrants further investigation.

Vitamin D and the cardiovascular system: an overview of the recent literature

Since the discovery that the enzyme catalyzing the synthesis of the most active natural vitamin D metabolite(calcitriol) and the vitamin D-specific receptor (VDR)were expressed in a wide range of tissues and organs, not only involved in the mineral metabolism (MM), there has been increasing interest on the putative ‘non classical’ roles of vitamin D metabolites, particularly on their possible effects on the cardiovascular (CV) system. These hypothetical CV effects of vitamin D gained particular interesting the nephrology field, given the high prevalence of CV disease in patients affected by either acute or chronic kidney diseases. However, notwithstanding a huge amount of experimental data suggesting a possible protective role of vitamin D on the CV system, the conclusions of two recent meta-analyses from the Cochrane group and a recent statement from the Institute of Medicine, based on a complete revision of the available data, concluded that there is no clear evidence for a role of vitamin D other than that strictly associated with bone health. However, a continuous and increasing flow of new studies still continues to add information on this topic. In the present review, we have tried to critically address the data added on this topicin the last 2 years, considering separately the experimental,observational, and intervention studies that have appeared in PubMed in the last 2 years, discussing the data providing proof, pro or contra, the involvement of vitamin D in CV disease, both in the absence or presence of kidney function impairment.

Vitamin D status was not associated with 'one-year' progression of coronary artery disease, assessed by coronary angiography in statin-treated patients

BACKGROUND

Low vitamin D status is associated with increased risk of cardiovascular disease and may be involved in atherosclerosis. Our aim was to assess the association between vitamin D status and the progression of coronary artery disease (CAD).

METHODS AND RESULTS

We measured 25-hydroxyvitamin D3 (25OHD3) by liquid chromatography tandem mass spectrometry (LC-MS/MS) in plasma from 348 participants with established CAD (84% males, mean ± standard deviation (SD) age 60 ± 10 years) of the Western Norway B-vitamin Intervention Trial (WENBIT, 1999-2006). The patients underwent invasive coronary angiography (CA) and percutaneous coronary intervention at baseline and a second CA after 302 ± 79 days of follow-up. From the angiograms, minimal lumen diameter (MLD) and diameter stenosis (DS) of atherosclerotic lesions were obtained. Significant CAD in non-intervened vessels was found in 309 coronary arteries from 183 participants either at baseline and/or at follow-up. To assess the association between levels of 25OHD3 and CAD progression in non-intervened vessels, we applied a linear quantile fitted mixed effects model with MLD or DS measured at follow-up as a function of continuous 25OHD3 concentrations. There were no statistically significant associations between plasma 25OHD3 concentrations (median: 63.9, 95% confidence interval (CI): 48.1-78.5 nmol/l) measured at baseline and the follow-up measures of either MLD (estimated effect per 10 nmol/l increase of 25OHD3 and 95% CI: -0.015 (-0.032-0.002) mm, p = 0.088) or DS (0.225 (-0.354-0.804) percentage points, p = 0.444). Multivariate adjustment did not alter these results.

CONCLUSION

Plasma 25OHD3 levels were not associated with 'one-year' progression of CAD, assessed by CA in statin-treated patients.

Vitamin D deficiency is associated with development of subclinical coronary artery disease in HIV-infected African American cocaine users with low Framingham-defined cardiovascular risk

Chronic cocaine use may lead to premature atherosclerosis, but the prevalence of and risk factors for coronary artery disease (CAD) in asymptomatic cocaine users have not been reported. The objective of this study was to examine whether vitamin D deficiency is associated with the development of CAD in human immunodeficiency virus (HIV)-infected African American cocaine users with low CAD risk.

METHODS

In this prospective follow-up study, we investigated 169 HIV-infected African American cocaine users with low Framingham risk at baseline. The main outcome measures were incidence of subclinical CAD and development of subclinical CAD.

RESULTS

Fifty of the 169 African Americans had evidence of subclinical disease on the initial cardiac computed tomography. A second cardiac computed tomography was performed on the 119 African Americans without disease on the first scan. The total sum of person-years of follow-up was 289.6. Subclinical CAD was detected in 11 of these, yielding an overall incidence of 3.80/100 person-years (95% confidence interval 1.90-6.80). Among the factors investigated, only vitamin D deficiency was independently associated with development of subclinical CAD. The study did not find significant associations between CD4 count, HIV viral load, or antiretroviral treatment use and the incidence of subclinical CAD. This study appears to suggest that there is a threshold level of vitamin D (10 ng/mL) above which the effect of vitamin D on subclinical CAD is diminished.

CONCLUSION

The incidence of subclinical CAD in HIV-infected African American cocaine users with low CAD risk is high, especially in those with vitamin D deficiency. Well designed randomized clinical trials are warranted to confirm the role of vitamin D deficiency in the development of CAD in HIV-infected African American cocaine users with low CAD risk.

The role of vitamin D deficiency in cardiovascular disease: where do we stand in 2013?

The high worldwide prevalence of vitamin D deficiency is largely the result of low sunlight exposure with subsequently limited cutaneous vitamin D production. Classic manifestations of vitamin D deficiency are linked to disturbances in bone and mineral metabolism, but the identification of the vitamin D receptor in almost every human cell suggests a broader role of vitamin D for overall and cardiovascular health. The various cardiovascular protective actions of vitamin D such as anti-diabetic and anti-hypertensive effects including renin suppression as well as protection against atherosclerosis and heart diseases are well defined in previous experimental studies. In line with this, large epidemiological studies have highlighted vitamin D deficiency as a marker of cardiovascular risk. However, randomized controlled trials (RCTs) on vitamin D have largely failed to show its beneficial effects on cardiovascular diseases and its conventional risk factors. While most prior vitamin D RCTs were not designed to assess cardiovascular outcomes, some large RCTs have been initiated to evaluate the efficacy of vitamin D supplementation on cardiovascular events in the general population. When considering the history of previous disappointing vitamin RCTs in general populations, more emphasis should be placed on RCTs among severely vitamin D-deficient populations who would most likely benefit from vitamin D treatment. At present, vitamin D deficiency can only be considered a cardiovascular risk marker, as vitamin D supplementation with doses recommended for osteoporosis treatment is neither proven to be beneficial nor harmful in cardiovascular diseases.

Circulating vitamin D metabolites and subclinical atherosclerosis in type 1 diabetes

OBJECTIVE

People with type 1 diabetes are at high risk of premature atherosclerosis. Existing evidence suggests that impaired vitamin D metabolism may contribute to the development of atherosclerosis. We tested associations of circulating vitamin D metabolite concentrations with subclinical atherosclerosis among 1,193 participants with type 1 diabetes in the DCCT/EDIC study.

RESEARCH DESIGN AND METHODS

We measured plasma concentrations of 25-hydroxyvitamin D [25(OH)D], 1,25-dihydroxyvitamin D, and 24,25-dihydroxyvitamin D by mass spectrometry at the end of the DCCT. In a staggered cross-sectional design, we tested associations with coronary artery calcium (CAC), measured by computed tomography a median of 10 years later, and with common and internal carotid intima-media thickness (IMT), measured by B-mode ultrasonography on two occasions a median of 4 years later and a median of 10 years later. We hypothesized that lower concentrations of each vitamin D metabolite would be associated with increased risk of CAC and greater carotid IMT. RESULTS At the time metabolites were measured, mean age was 32.4 years and mean duration of diabetes was 7.5 years. The prevalence and severity of CAC tended to be lower-not higher-with lower concentrations of each vitamin D metabolite. For instance, in a fully adjusted multinomial logistic model, a 25 nmol/L lower 25-hydroxyvitamin D was associated with a 0.8-fold decrease in the odds of having higher CAC (95% CI 0.68-0.96, P = 0.01). No vitamin D metabolite was associated with either common or internal mean IMT.

CONCLUSIONS

We did not find evidence linking impaired vitamin D metabolism with increased subclinical atherosclerosis in type 1 diabetes.

Vitamin D and cardiovascular disease

Vitamin D deficiency, as well as cardiovascular diseases (CVD) and related risk factors are highly prevalent worldwide and frequently co-occur. Vitamin D has long been known to be an essential part of bone metabolism, although recent evidence suggests that vitamin D plays a key role in the pathophysiology of other diseases, including CVD, as well. In this review, we aim to summarize the most recent data on the involvement of vitamin D deficiency in the development of major cardiovascular risk factors: hypertension, obesity and dyslipidemia, type 2 diabetes, chronic kidney disease and endothelial dysfunction. In addition, we outline the most recent observational, as well as interventional data on the influence of vitamin D on CVD. Since it is still an unresolved issue whether vitamin D deficiency is causally involved in the pathogenesis of CVD, data from randomized controlled trials (RCTs) designed to assess the impact of vitamin D supplementation on cardiovascular outcomes are awaited with anticipation. At present, we can only conclude that vitamin D deficiency is an independent cardiovascular risk factor, but whether vitamin D supplementation can significantly improve cardiovascular outcomes is still largely unknown.

Vascular calcification in diabetes: mechanisms and implications

Cardiovascular disease (CVD) remains the leading cause of death among adults with diabetes, and CVD prevention remains a major challenge. Coronary artery calcium (CAC) score measured by electron beam tomography (EBT) or multi-slice detector computed tomography correlates closely with plaque burden and coronary angiography, and predicts coronary events independently of other risk factors. Further, progression of CAC over several years has been shown to predict increased mortality. Coronary calcification is an active process strongly associated with atherosclerotic plaque evolution and is an accepted surrogate endpoint in studies of patients with diabetes older than 30. In this review, recent findings regarding the mechanisms and implications of vascular calcification in diabetes will be discussed.