Vitamin D and cardiovascular disease will it live up to its hype?

Relationship between vitamin D levels and intravenous immunoglobulin resistance in Kawasaki disease

Purpose

Vitamin D is associated with various pathological conditions such as cardiovascular diseases and cancer. We investigated the relationship between vitamin D and Kawasaki disease (KD).

Methods

We performed a retrospective review of the medical records of patients with KD between February 2013 and March 2016 in Daegu Fatima Hospital. Study participants were grouped according to vitamin D serum concentration. Group 1 included patients with 25(OH)-vitamin D ≥20 ng/mL. Group 2 included patients with 25(OH)-vitamin D <20 ng/mL. We analyzed the clinical characteristics and laboratory data of the 2 groups.

Results

Of the 91 patients, 52 were included in group 1, and 39 in group 2. Group 1 patients had significantly higher levels of calcium, phosphate, albumin and sodium than group 2 patients did. There were no differences in clinical characteristics, but the proportion of patients with polymorphic rash was significantly higher in group 2. Resistance to intravenous immunoglobulin was more frequent in group 2 (P=0.023). No significant difference in the incidence of coronary artery complications was observed.

Conclusion

Low vitamin D levels are associated with resistance to intravenous immunoglobulin therapy in KD. Vitamin D deficiency might be a risk factor for immunoglobulin resistance in KD.

Vitamin D and Cardiovascular Disease: Can Novel Measures of Vitamin D Status Improve Risk Prediction and Address the Vitamin D Racial Paradox?

PURPOSE OF REVIEW

To provide a state-of-the-art update on some emerging measures of vitamin D status and discuss how assessment of these key vitamin D metabolites might improve prognostication of risk for cardiovascular disease (CVD) outcomes.

RECENT FINDINGS

Vitamin D deficiency is a highly prevalent condition and relatively easy to treat with supplementation and/or modest sunlight exposure. A substantial body of experimental and epidemiological evidence suggest that vitamin D deficiency is a risk factor for CVD. Most epidemiologic studies to date have focused on total 25-hydroxyvitamin D [25(OH)D] concentrations, which is the established marker of vitamin D stores. However, there is emerging evidence that other novel markers of vitamin D metabolism may better characterize 'true' vitamin D status. Some key novel measures include bioavailable 25(OH)D, free 25(OH)D, 1-25 dihydroxyvitamin D, 24,25-dihydroxyvitamin D3 [24,25(OH)₂D3], and ratio of 24,25(OH)₂D3 to 25(OH)D [the vitamin D metabolic ratio]. Utilization of these biomarkers may enhance understanding of the association between vitamin D and CVD risk, and may provide explanation for the observation that 25(OH)D is a stronger CVD risk factor in whites than blacks.

SUMMARY

Novel measures of vitamin D status could potentially change clinical practice regarding how patients are currently screened for vitamin D status and defined as vitamin D deficient or not. However, whether measuring any of these alternate markers of vitamin D status can provide further insight regarding CVD risk beyond the traditionally measured 25(OH)D concentrations is uncertain at this time. This is an area where further research is strongly needed.

Calcium Phosphate Product Is Associated with Subclinical Carotid Atherosclerosis in Type 2 Diabetes

AIMS

To assess whether circulating 25-hydroxyvitamin D₃ (25OHD) and mineral metabolism-related factors (serum phosphate, calcium, and parathormone) are associated with subclinical carotid atherosclerosis (SCA), defined as the presence of carotid atherosclerotic plaques (main study outcome), in patients with type 2 diabetes mellitus (T2DM) without kidney disease or previous cardiovascular disease.

METHODS

We undertook a post hoc analysis of a cross-sectional study in adults with T2DM in whom we evaluated SCA. A total of 303 subjects with T2DM were included. Clinical variables and carotid ultrasound imaging were obtained.

RESULTS

We found no association of 25OHD with the presence of SCA. However, calcium phosphate (CaP; mg²/dL²) product was positively associated with the presence of carotid plaques (OR_adj = 1.078; 95% CI: 1.017-1.142). An inverse association was observed between higher levels of 25OHD (≥30 ng/mL versus <20 ng/mL concentrations) and common carotid intima-media thickness (cIMT; mm) (β_adj ± SE = -0.055 ± 0.024). We conclude that the CaP product is independently associated with the presence of established subclinical carotid atherosclerosis in patients with T2DM.

High-risk periodontal pathogens contribute to the pathogenesis of atherosclerosis

Periodontal disease (PD) is generated by microorganisms. These microbes can enter the general circulation causing a bacteraemia. The result can be adverse systemic effects, which could promote conditions such as cardiovascular disease. Level A evidence supports that PD is independently associated with arterial disease. PD is a common chronic condition affecting the majority of Americans 30 years of age and older. Atherosclerosis remains the largest cause of death and disability. Studies indicate that the adverse cardiovascular effects from PD are due to a few putative or high-risk bacteria: Aggregatibacter actinomycetemcomitans, Porphyromonas gingivalis, Tannerella forsythia, Treponema denticola or Fusobacterium nucleatum. There are three accepted essential elements in the pathogenesis of atherosclerosis: lipoprotein serum concentration, endothelial permeability and binding of lipoproteins in the arterial intima. There is scientific evidence that PD caused by the high-risk pathogens can influence the pathogenesis triad in an adverse manner. With this appreciation, it is reasonable to state PD, due to high-risk pathogens, is a contributory cause of atherosclerosis. Distinguishing this type of PD as causal provides a significant opportunity to reduce arterial disease.

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.

Pleiotropic protective effects of Vitamin D against high fat diet-induced metabolic syndrome in rats: One for all

Several lines of evidence point to the association of vitamin D deficiency with the different components of metabolic syndrome. Yet, the effect of vitamin D supplementation on metabolic syndrome is not clearly elucidated. Herein, we tested the hypothesis that administration of vitamin D, either alone or in combination of metformin can improve metabolic and structural derangements associated with metabolic syndrome. Fifty wistar rats were randomly assigned to serve either as normal control (10 rats) or metabolic syndrome rats, by feeding them with a standard or a high fat diet (HFD), respectively. Metabolic syndrome rats were further assigned to receive either vehicle, Metformin (100mg/Kg orally), vitamin D (6ng/Kg SC.) or both, daily for 8 weeks. Body weight, blood pressure, serum glucose, insulin, insulin resistance, lipid profile, oxidative stress, serum uric acid and Ca⁺² were assessed at the end of the study. Histopathological examination of hepatic, renal and cardiac tissues were also performed. Treatment with vitamin D was associated with a significant improvement of the key features of metabolic syndrome namely obesity, hypertension and dyslipidaemia with a neutral effect on Ca⁺² level. When combined with metformin, most of the other metabolic abnormalities were ameliorated. Furthermore, a significant attenuation of the associated hepatic steatosis was observed with vitamin D as well as vitamin D/metformin combination. In conclusion, vitamin D can improve hypertension, metabolic and structural abnormalities induced by HFD, and it provides additional benefits when combined with metformin. Therefore, vitamin D could represent a feasible therapeutic option for prevention of metabolic syndrome.

Seasonal Vitamin D Status in Polish Elite Athletes in Relation to Sun Exposure and Oral Supplementation

Vitamin D does not only influence the musculoskeletal health and mineral homeostasis but it also affects cardiovascular, endocrine, nervous, immune and mental functions, thus it is of considerable importance for both physically active people and elite athletes. However, vitamin D deficiency is common worldwide and results from inadequate endogenous skin synthesis (insufficient ultraviolet B exposure) and diet. To improve the vitamin D status elite athletes often travel to lower latitude during winter. The aim of the study was to evaluate the seasonal vitamin D status in Polish elite athletes according to the sun exposure and oral supplementation. Serum concentration of 25-hydroxyvitamin D (25(OH)D) was measured in the years 2010–2014 in 409 elite athletes, who were divided into the following groups: OUTD—outdoor sports, represented by track and field athletes, who trained in Poland; IND—weightlifters, handball and volleyball players who trained indoors in Poland; SUN—track and field athletes who trained during Polish winter in lower latitude with high sunshine exposure; SUPL—track and field athletes who trained in Poland, had an inadequate vitamin D status (25(OH)D < 30 ng/ml) and were supplemented orally. Inadequate Vitamin D status was observed in 80% of OUTD and 84% of IND athletes in winter, whereas in summer the values amounted to 42% and 83%, respectively. The athletes exposed to sun in winter had significantly higher vitamin D concentration than OUTD group. Oral supplementation improved vitamin D concentration by 45%, whereas winter sun exposure caused its increase by 85%. Except for a few summer months an inadequate status of vitamin D was found in the majority of Polish elite athletes, with the deficiency level being similar to the one observed in non-athletic population. The most serious deficiency was observed in indoor disciplines. Adequate vitamin D status can be achieved by both increased sun exposure, especially in winter, and oral supplementation. Athletes should therefore routinely assess their vitamin D status and be educated how to approach their sunlight exposure, diet and supplementation.

Relationship between plasma level of vitamin D and post operative atrial fibrillation in patients undergoing CABG

Objective:

Atrial fibrillation is the most common arrhythmia after cardiac surgery. Several studies have shown the impact of vitamin D on heart disease; however, there have been few studies for the incidence of AF and its relationship with vitamin D levels. According to the different results of these studies, we decided to evaluate the relation of plasma levels of vitamin D and postoperative atrial fibrillation in patients undergoing coronary artery bypass surgery (CABG).

Methods:

This cross-sectional study was performed on 50 patients after CABG surgery. Simple random sampling was done. Twenty five patients who developed AF within 48 hours after CABG with Cardiopulmonary bypass (CPB) were enrolled in the case group and 25 patients who did not develop AF within 48 hours after CABG with CPB were enrolled in the control group. Plasma levels of vitamin D in both groups of patients were recorded. Collected data were analyzed by the SPSS software version 17.

Results:

There was no significant difference in terms of demographic characteristics, comorbidities, lipid profile and kidney function between two groups. The mean plasma level of vitamin D was 27.4 ± 2.22 ng/ml in the case group and was 28.2 ± 1.18 ng/ml in the control group it (p= 0.803).

Conclusions:

Plasma levels of vitamin D were almost the same in both groups and there was no statistically significant difference between the groups with and without atrial fibrillation following CABG.

Association between serum 25-hydroxyvitamin D concentrations and prevalence of metabolic syndrome

PURPOSE

There is now good evidence that 25-hydroxyvitamin D (25OHD) status may have an important impact on the development and progression of cardiovascular disease. Because of the potential involvement of vitamin D deficiency in blood pressure control and immune responses, we aimed to investigate whether there was a relationship between 25OHD status and the prevalence of metabolic syndrome in an Iranian population.

MATERIAL/METHODS

The study was carried out on a sample of 846 subjects [357(42.19%) males and 489(57.80%) females], derived from MASHAD STUDY. Serum 25OHD levels were measured using a competitive electroluminescence protein binding assay. Anthropometric indices were measured using standard protocols.

RESULTS

Serum 25OHD was 12.7 (6.8-18.4) ng/ml in the metabolic syndrome (MetS) group and 14.1 (8.8-19.0) ng/ml in the group without metabolic syndrome (P=0.43). The frequency of vitamin D deficiency was 80.7% and 79.0% in subjects with or without metabolic syndrome in Iranian population.

CONCLUSIONS

We found no significant difference in serum 25OHD concentrations between individuals with or without MetS and no significant linear relationship between serum 25OHD and several CVD risk factors.

Design and rationale of a multicentre, randomised, double-blind, placebo-controlled clinical trial to evaluate the effect of vitamin D on ventricular remodelling in patients with anterior myocardial infarction: the VITamin D in Acute Myocardial Infarction (VITDAMI) trial

INTRODUCTION

Decreased plasma vitamin D (VD) levels are linked to cardiovascular damage. However, clinical trials have not demonstrated a benefit of VD supplements on left ventricular (LV) remodelling. Anterior ST-elevation acute myocardial infarction (STEMI) is the best human model to study the effect of treatments on LV remodelling. We present a proof-of-concept study that aims to investigate whether VD improves LV remodelling in patients with anterior STEMI.

METHODS AND ANALYSIS

The VITamin D in Acute Myocardial Infarction (VITDAMI) trial is a multicentre, randomised, double-blind, placebo-controlled trial. 144 patients with anterior STEMI will be assigned to receive calcifediol 0.266 mg capsules (Hidroferol SGC)/15 days or placebo on a 2:1 basis during 12 months.

PRIMARY OBJECTIVE

to evaluate the effect of calcifediol on LV remodelling defined as an increase in LV end-diastolic volume ≥10% (MRI).

SECONDARY OBJECTIVES

change in LV end-diastolic and end-systolic volumes, ejection fraction, LV mass, diastolic function, sphericity index and size of fibrotic area; endothelial function; plasma levels of aminoterminal fragment of B-type natriuretic peptide, galectin-3 and monocyte chemoattractant protein-1; levels of calcidiol (VD metabolite) and other components of mineral metabolism (fibroblast growth factor-23 (FGF-23), the soluble form of its receptor klotho, parathormone and phosphate). Differences in the effect of VD will be investigated according to the plasma levels of FGF-23 and klotho. Treatment safety and tolerability will be assessed. This is the first study to evaluate the effect of VD on cardiac remodelling in patients with STEMI.

ETHICS AND DISSEMINATION

This trial has been approved by the corresponding Institutional Review Board (IRB) and National Competent Authority (Agencia Española de Medicamentos y Productos Sanitarios (AEMPS)). It will be conducted in accordance with good clinical practice (International Council for Harmonisation of Technical Requirements for Pharmaceuticals for Human Use - Good Clinical Practice (ICH-GCP)) requirements, ethical principles of the Declaration of Helsinki and national laws. The results will be submitted to indexed medical journals and national and international meetings.

TRIAL REGISTRATION NUMBER

NCT02548364; Pre-results.

The Association of Vitamin D Status with Dyslipidaemia and Biomarkers of Endothelial Cell Activation in Older Australians

Background/Aims: Vitamin D has been investigated for many non-skeletal effects. The objective of this study was to determine whether circulating lipids, systemic inflammation, and biomarkers of endothelial cell activation varied with the vitamin D status of older Australians. Methods: One hundred and one participants were proportionately and randomly sampled across tertiles of 25 hydroxy vitamin D (25(OH)D) from a larger cohort of free living older adults (T1 median = 97; T2 median = 74.5; T3 median = 56.8 nmol/L). Overnight fasting blood samples were assayed for 25(OH)D, parathyroid hormone (PTH), insulin, triacylglycerol (TAG), total cholesterol (TC), low density lipoprotein cholesterol (LDL-C) and high density lipoprotein cholesterol (HDL-C). Markers of systemic inflammation (high sensitivity C-reactive protein (hsCRP), tumour necrosis factor-α (TNF-α)) and endothelial activation (hepatocyte growth factor (HGF), P-selectin and soluble vascular cell adhesion molecule (sVCAM), soluble intracellular adhesion molecule (sICAM)) were determined. A general linear model multivariate analysis with a backward elimination procedure was performed. Results: Eighty-three participants (48 women, 35 men), aged 65 ± 7.7 years, BMI 28 ± 4.5 kg/m², with complete data were analyzed. The final parsimonious model controlled for age, gender, BMI, and McAuley’s index, but excluded season, medications, and PTH. There were significant differences across 25(OH)D tertiles in TC (T1 < T3, p = 0.003; T2 < T3, p = 0.001), LDL-C (T1 < T3, p = 0.005; T2 < T3, p = 0.001), TAG (T2 < T3, p = 0.026), HGF (T1 > T3, p = 0.009) and sVCAM (T1 > T3, P = 0.04). Conclusions: Higher vitamin D status may protect the endothelium through reduced dyslipidaemia and increased HGF.

Activation of the vitamin D receptor selectively interferes with calcineurin-mediated inflammation: a clinical evaluation in the abdominal aortic aneurysm

In vitro and in vivo studies attribute potent immune regulatory properties to the vitamin D receptor (VDR). Yet, it is unclear to what extend these observations translate to the clinical context of (vascular) inflammation. This clinical study evaluates the potential of a VDR agonist to quench vascular inflammation. Patients scheduled for open abdominal aneurysm repair received paricalcitol 1 μg daily during 2-4 weeks before repair. Results were compared with matched controls. Evaluation in a parallel group showed that AAA patients are vitamin D insufficient (median plasma vitamin D: 43 (30-62 (IQR)) nmol/l). Aneurysm wall samples were collected during surgery, and the inflammatory footprint was studied. The brief paricalcitol intervention resulted in a selective 73% reduction in CD4+ T-helper cell content (P<0.024) and a parallel 35% reduction in T-cell (CD3+) content (P<0.032). On the mRNA level, paricalcitol reduced expression of T-cell-associated cytokines IL-2, 4, and 10 (P<0.019). No effect was found on other inflammatory mediators. On the protease level, selective effects were found for cathepsin K (P<0.036) and L (P<0.005). Collectively, these effects converge at the level of calcineurin activity. An effect of the VDR agonist on calcineurin activity was confirmed in a mixed lymphocyte reaction. In conclusion, brief course of the VDR agonist paricalcitol has profound effects on local inflammation via reduced T-cell activation. The anti-inflammatory potential of VDR activation in vitamin D insufficient patients is highly selective and appears to be mediated by an effect on calcineurin-mediated responses.

Assessment of 25-OH vitamin D levels and abnormal blood pressure response in female patients with cardiac syndrome X

Objective:

Vitamin D deficiency is associated with coronary artery disease, hypertension, heart failure, endothelial dysfunction, and metabolic syndrome. The pathophysiology of cardiac syndrome X (CSX) involves many pathways that are influenced by vitamin D levels. This study aimed to investigate the relationship between vitamin D deficiency and abnormal blood pressure response to exercise in patients with CSX.

Methods:

This was a cross-sectional and observational study. Fifty females with normal epicardial coronary arteries who presented with typical symptoms of rest or effort angina and 41 healthy age-matched female controls, were included. Patients with cardiomyopathy, severe valvular disease, congenital heart disease, and left ventricular hypertrophy were excluded. All patients underwent stress electrocardiography examination and 25-hydroxy (OH) vitamin D level measurements.

Results:

Levels of 25-OH vitamin D were significantly lower in CSX patients (9.8±7.3 ng/mL vs. 18.1±7.9 ng/mL; p<0.001). Systolic blood pressure (SBP) (188±15 mm Hg vs. 179±17 mm Hg; p=0.013) and diastolic blood pressure (DBP) (98±9 mm Hg vs. 88±9 mm Hg; p<0.001) during peak exercise were higher in CSX patients. Levels of 25-OH vitamin D were negatively correlated with peak SBP (r=–0.310, p=0.004) and peak DBP (r=–0.535, p<0.001) during exercise. To discard the multicollinearity problem, two different models were used for multivariate analyses. In the first model, metabolic equivalents (METs) (p=0.003) and 25-OH vitamin D levels (p=0.001) were independent predictors. METs (p=0.007), 25-OH vitamin D levels (p=0.008), and peak DBP were determined as independent predictors in the second multivariate model.

Conclusion:

In patients with CSX, 25-OH vitamin D levels were lower than those in controls; moreover, 25-OH vitamin D deficiency was also associated with higher levels of peak DBP during exercise. (Anatol J Cardiol 2016; 16: 961-6)

Plasma Levels of Monocyte Chemoattractant Protein-1, n-Terminal Fragment of Brain Natriuretic Peptide and Calcidiol Are Independently Associated with the Complexity of Coronary Artery Disease

Background and Objectives

We investigated the relationship of the Syntax Score (SS) and coronary artery calcification (CAC), with plasma levels of biomarkers related to cardiovascular damage and mineral metabolism, as there is sparse information in this field.

Methods

We studied 270 patients with coronary disease that had an acute coronary syndrome (ACS) six months before. Calcidiol, fibroblast growth factor-23, parathormone, phosphate and monocyte chemoattractant protein-1 [MCP-1], high-sensitivity C-reactive protein, galectin-3, and N-terminal pro-brain natriuretic peptide [NT-proBNP] levels, among other biomarkers, were determined. CAC was assessed by coronary angiogram as low-grade (0–1) and high-grade (2–3) calcification, measured with a semiquantitative scale ranging from 0 (none) to 3 (severe). For the SS study patients were divided in SS<14 and SS≥14. Multivariate linear and logistic regression analyses were performed.

Results

MCP-1 predicted independently the SS (RC = 1.73 [95%CI = 0.08–3.39]; p = 0.040), along with NT-proBNP (RC = 0.17 [95%CI = 0.05–0.28]; p = 0.004), male sex (RC = 4.15 [95%CI = 1.47–6.83]; p = 0.003), age (RC = 0.13 [95%CI = 0.02–0.24]; p = 0.020), hypertension (RC = 3.64, [95%CI = 0.77–6.50]; p = 0.013), hyperlipidemia (RC = 2.78, [95%CI = 0.28–5.29]; p = 0.030), and statins (RC = 6.12 [95%CI = 1.28–10.96]; p = 0.013). Low calcidiol predicted high-grade calcification independently (OR = 0.57 [95% CI = 0.36–0.90]; p = 0.013) along with ST-elevation myocardial infarction (OR = 0.38 [95%CI = 0.19–0.78]; p = 0.006), diabetes (OR = 2.35 [95%CI = 1.11–4.98]; p = 0.028) and age (OR = 1.37 [95%CI = 1.18–1.59]; p<0.001). During follow-up (1.79 [0.94–2.86] years), 27 patients developed ACS, stroke, or transient ischemic attack. A combined score using SS and CAC predicted independently the development of the outcome.

Conclusions

MCP-1 and NT-proBNP are independent predictors of SS, while low calcidiol plasma levels are associated with CAC. More studies are needed to confirm these data.

Association of Low Levels of Vitamin D with Chronic Stable Angina: A Prospective Case-Control Study

Background:

Coronary artery disease (CAD) is a major cause of death and disability in developed countries. Chronic stable angina is the initial manifestation of CAD in approximately 50% of the patients. Recent evidence suggests that vitamin D is crucial for cardiovascular health. The prevalence of vitamin D deficiency in our region is 83%. A low level of vitamin D is associated with chronic stable angina.

Aim:

This study was aimed at supporting or refuting this hypothesis in our population.

Materials and Methods:

The study was a prospective case-control study. We studied 100 cases of chronic stable angina and compared them with 100 matched controls. Vitamin D deficiency was defined as <20 ng/mL, vitamin D insufficiency as 20-30 ng/mL and normal vitamin D level as 31-150 ng/mL.

Results:

The prevalence of vitamin D deficiency among cases and controls was 75% and 10%, respectively. 75% of the cases were vitamin D-deficient (<20 ng/mL); 12% were vitamin D-insufficient (20-30 ng/mL), and 13% had normal vitamin D levels (31-150 ng/mL). None had a toxic level of vitamin D. Among the controls, 10% were vitamin D-deficient, 33% were vitamin D-insufficient, and 57% had normal vitamin D levels. The mean vitamin level among cases and controls was 15.53 ng/mL and 40.95 ng/mL, respectively, with the difference being statistically significant (P ≤ 0.0001). There was no statistically significant relation between the disease severities, i.e., on coronary angiography (CAG) with vitamin D level. Among the cases, we found that an increasing age was inversely related to vitamin D levels (P = 0.027).

Conclusion:

Our study indicates a correlation between vitamin D deficiency and chronic stable angina. Low levels may be an independent, potentially modifiable cardiovascular risk factor.

[Vitamin D deficiency in chronic liver disease, clinical-epidemiological analysis and report after vitamin d supplementation]

INTRODUCTION

Vitamin D (VD) is known to have multiple extra-skeletal health functions. There is emerging interest in exploring the relationship between vitamin D and chronic liver disease (CLD).

OBJECTIVES

To determine the prevalence of VD deficiency in patients with CLD in our setting and to assess whether VD supplementation influences plasma levels and is associated with improved liver function.

MATERIAL AND METHODS

We conducted a study in 2 phases. First, we analysed clinical and epidemiological characteristics in 94 patients with CLD; second, different doses of calcifediol (25-OH-VD) were administered to patients with VD deficiency (<20ng/mL) and insufficiency (20-30ng/mL). Plasma concentrations and liver function (Child-Pugh and MELD) at the end of treatment were compared with baseline data.

RESULTS

Deficient or insufficient VD levels were found in 87% of the patients, with an average concentration of 18.8ng/mL. Levels were lower in patients with cirrhosis (15.9ng/mL) (P=.002) and in alcoholic liver disease. VD levels were inversely proportional to the degree of liver function: Child A (16.52ng/mL) vs C (7.75ng/mL). After VD supplementation, optimal serum levels were achieved in 94% of patients and significant improvements were observed in platelet count, albumin levels (P<.05) and functional status assessed by the Child-Pugh scale (P<.05).

CONCLUSION

Given the high prevalence of VD deficiency or insufficiency, the need for screening should be considered in the population with CLD. VD supplementation could be safe and effective.

Vitamin D deficiency and its characteristics among patients with acute stroke at a national referral hospital in Kampala Uganda

BACKGROUND

Vitamin D deficiency has been associated with acute stroke and other cardiovascular diseases in the developed world. Low 25-hydroxyvitamin D (25OHD) has been described in some populations in Sub-Saharan Africa (SSA) in spite of adequate sunshine all year round. There is no information on the magnitude of vitamin D deficiency among patients with stroke and other cardiovascular diseases in Uganda or SSA. The aim of this study was to determine the burden and characteristics of vitamin D deficiency among patients with acute stroke, the most common form of cardiovascular events in SSA.

METHODS

We conducted a cross-sectional study between October 2012 and March 2013. We consecutively recruited 142 subjects with acute stroke admitted to the medical wards of Mulago hospital. We administered a pre-tested questionnaire to the study participants, and did a detailed physical examination and laboratory evaluation. Serum levels of 25OHD were determined using an electrochemiluminescence assay. Data were analyzed using STATA version 12 software.

RESULTS

The prevalence of vitamin D deficiency (25OHD < 20 ng/ml) was 15 %. Longer hours of sunshine exposure decreased the likelihood vitamin D deficiency significantly (adjusted OR 0.85, p = 0.03). Higher HDL cholesterol had a significant inverse association with vitamin D deficiency (adjusted OR 0.15, p = 0.02). In addition, the likelihood of vitamin D deficiency increased with rising age (adjusted OR 1.03, p = 0.05).

CONCLUSIONS

There was a relatively low burden of vitamin D deficiency among patients with acute stroke in Uganda. With increasing longevity and indoor lifestyles vitamin D deficiency may assume a greater role in stroke and other cardiovascular diseases in tropical sub Saharan Africa. Future studies on the mechanisms of vitamin D deficiency and its relationship to outcomes among patients with stroke may be necessary.

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.

Vitamin D Status in Rheumatoid Arthritis: Inflammation, Arterial Stiffness and Circulating Progenitor Cell Number

Background and Aims

Suboptimal vitamin D status was recently acknowledged as an independent predictor of cardiovascular diseases and all-cause mortality in several clinical settings, and its serum levels are commonly reduced in Rheumatoid Arthritis (RA). Patients affected by RA present accelerated atherosclerosis and increased cardiovascular morbidity and mortality with respect to the general population. In RA, it has been reported an impairment of the number and the activity of circulating proangiogenic haematopoietic cells (PHCs), including CD34+, that may play a role in endothelial homeostasis. The purpose of the study is to investigate the association between vitamin D levels and PHCs, inflammatory markers, and arterial stiffening in patients with RA.

Methods and Results

CD34+ cells were isolated from 27 RA patients and 41 controls. Vitamin D levels, C-reactive protein (CRP), fibrinogen, pulse wave velocity (PWV), and carotid intima-media thickness (cIMT) were also evaluated. CD34+ count and vitamin D levels were lower in RA patients as compared to controls, while fibrinogen, CRP, PWV and cIMT were higher in RA patients. CD34+ cell number appeared to be associated with vitamin D levels, and negatively correlated to fibrinogen and early atherosclerosis markers (PWV and cIMT); vitamin D levels appear also to be inversely associated to fibrinogen.

Conclusions

RA patients with moderate disease activity presented with low vitamin D levels, low CD34+ cell count, increased PWV and cIMT; we found that vitamin D deficiency is associated to CD34+ cell reduction in peripheral blood, and with fibrinogen levels. This suggests that vitamin D might contribute to endothelial homeostasis in patients with RA.

Vitamin D and Anaesthesia

Vitamin D is a vitamin not only associated with calcium-phosphorus metabolism but also affects many organ systems. Because of its effect on the immune system in recent years, it has attracted much attention. Vitamin D deficiency is a clinical condition that can be widely observed in the society. Thus, patients with vitamin D deficiency are often seen in anaesthesia practice. In the absence of vitamin D, prolongation of intensive care unit stay, increase in mortality and morbidity and also association of chronic diseases further increase the importance of vitamin D deficiency. The results obtained from studies have led to the question of whether poor surgical outcome is associated with vitamin D deficiency. We assessed the vitamin D deficiency and its negative consequences for the anaesthesiologist.

Low 25-hydroxyvitamin D2 and 25-hydroxyvitamin D3 levels are independently associated with macroalbuminuria, but not with retinopathy and macrovascular disease in type 1 diabetes: the EURODIAB prospective complications study

Background

Low circulating levels of total vitamin D [25(OH)D] and 25(OH)D₃ have been associated with vascular complications in few studies on individuals with type 1 diabetes. However, these measures are affected by UV light exposure. Circulating 25(OH)D₂, however, solely represents dietary intake of vitamin D₂, but its association with complications of diabetes is currently unknown. We investigated the associations between 25(OH)D₂ and 25(OH)D₃ and the prevalence of albuminuria, retinopathy and cardiovascular disease (CVD) in individuals with type 1 diabetes.

Methods

We measured circulating 25(OH)D₂ and 25(OH)D₃ in 532 individuals (40 ± 10 years old, 51 % men) with type 1 diabetes who participated in the EURODIAB Prospective Complications Study. Cross-sectional associations of 25(OH)D₂ and 25(OH)D₃ with albuminuria, retinopathy and CVD were assessed with multiple logistic regression analyses adjusted for age, sex, season, BMI, smoking, HbA_1c, total-HDL-cholesterol-ratio, systolic blood pressure, antihypertensive medication, eGFR, physical activity, alcohol intake, albuminuria, retinopathy and CVD, as appropriate.

Results

Fully adjusted models revealed that 1 nmol/L higher 25(OH)D₂ and 10 nmol/L higher 25(OH)D₃ were associated with lower prevalence of macroalbuminuria with ORs (95 % CI) of 0.56 (0.43;0.74) and 0.82 (0.72;0.94), respectively. These vitamin D species were not independently associated with microalbuminuria, non-proliferative and proliferative retinopathy or CVD.

Conclusions

In individuals with type 1 diabetes, both higher 25(OH)D₂ and 25(OH)D₃ are associated with a lower prevalence of macroalbuminuria, but not of retinopathy and CVD. Prospective studies are needed to further examine the associations between 25(OH)D₂ and 25(OH)D₃ and the development of microvascular complications and CVD in type 1 diabetes.

Electronic supplementary material

The online version of this article (doi:10.1186/s12933-015-0231-2) contains supplementary material, which is available to authorized users.

Antihypertensive and neuroprotective actions of pyridoxine and its derivatives

Vitamin B6 plays a crucial role in the nervous system as the amino acid decarboxylases involved in the synthesis of all putative neurotransmitters requires the coenzyme pyridoxal phosphate. Vitamin B6 in its various forms has antioxidant properties. Pyridoxal phosphate has a role in regulating cellular calcium transport through both the voltage-mediated and ATP-mediated purinergic mechanisms of cellular calcium influx and, hence, has a role in the control of hypertension. Pharmacological doses of vitamin B6 appear to decrease the high blood pressure associated with both genetic and nongenetic models of hypertension. Vitamin B6 has a crucial role in the normal function of the central and peripheral nervous systems. It also protects against ischemia and glutamate-induced neurotoxicity.

Vitamin D plasma levels and in-hospital and 1-year outcomes in acute coronary syndromes: a prospective study

Deficiency in 25-hydroxyvitamin D (25[OH]D), the main circulating form of vitamin D in blood, could be involved in the pathogenesis of acute coronary syndromes (ACS). To date, however, the possible prognostic relevance of 25 (OH)D deficiency in ACS patients remains poorly defined. The purpose of this prospective study was to assess the association between 25 (OH)D levels, at hospital admission, with in-hospital and 1-year morbidity and mortality in an unselected cohort of ACS patients.We measured 25 (OH)D in 814 ACS patients at hospital presentation. Vitamin D serum levels >30 ng/mL were considered as normal; levels between 29 and 21 ng/mL were classified as insufficiency, and levels < 20 ng/mL as deficiency. In-hospital and 1-year outcomes were evaluated according to 25 (OH)D level quartiles, using the lowest quartile as a reference.Ninety-three (11%) patients had normal 25 (OH)D levels, whereas 155 (19%) and 566 (70%) had vitamin D insufficiency and deficiency, respectively. The median 25 (OH)D level was similar in ST-elevation myocardial infarction (STEMI) and non-ST-elevation myocardial infarction (NSTEMI) patients (14.1 [IQR 9.0-21.9] ng/mL and 14.05 [IQR 9.1-22.05] ng/mL, respectively; P = .88). The lowest quartile of 25 (OH)D was associated with a higher risk for several in-hospital complications, including mortality. At a median follow-up of 366 (IQR 364-379) days, the lowest quartile of 25 (OH)D, after adjustment for the main confounding factors, remained significantly associated to 1-year mortality (P < .01). Similar results were obtained when STEMI and NSTEMI patients were considered separately.In ACS patients, severe vitamin D deficiency is independently associated with poor in-hospital and 1-year outcomes. Whether low vitamin D levels represent a risk marker or a risk factor in ACS remains to be elucidated.

Independent association of severe vitamin D deficiency as a risk of acute myocardial infarction in Indians

BACKGROUND

Association of vitamin D deficiency with coronary heart disease (CHD) has been widely reported. Emerging data has shown high prevalence of vitamin D deficiency among Indians. However, this association has not been studied in Indians.

METHODS

A case-control study with 120 consecutive cases of first incident acute myocardial infarction (MI) and 120 age and gender matched healthy controls was conducted at All India Institute of Medical Sciences, New Delhi. The standard clinical and biochemical risk factors for MI were assessed for both cases and controls. Serum 25 (OH) vitamin D assay was performed from stored samples for cases and controls using radioimmunoassay.

RESULTS

Vitamin D deficiency [25(OH) D < 30 ng/ml] was highly prevalent in cases and controls (98.3% and 95.8% respectively) with median levels lower in cases (6 ng/ml and 11.1 ng/ml respectively; p < 0.001). The cases were more likely to have diabetes, hypertension and consume tobacco and alcohol. They had higher waist hip ratio, total and LDL cholesterol. Multivariate logistic regression analysis revealed severe vitamin D deficiency [25(OH) vitamin D < 10 ng/ml] was associated with a risk of MI with an odds ratio of 4.5 (95% CI 2.2-9.2).

CONCLUSIONS

This study reveals high prevalence of vitamin D deficiency among cases of acute MI and controls from India, with levels of 25 (OH)D being significantly lower among cases. Despite rampant hypovitaminosis, severe vitamin D deficiency was associated with acute MI after adjusting for conventional risk factors. This association needs to be tested in larger studies in different regions of the country.

Serum vitamin D and parathyroid hormone profiles in patients with various stages of renal disease

BACKGROUND

The prevalence of vitamin D deficiency among Saudi population has increased recently. The social and pathological factors, including kidney disease that may have influenced the vitamin status have not been investigated in the Hail population.

AIMS

The present study aims to: (1) investigate changes in the serum vitamin D, parathyroid hormone, serum calcium, and phosphate levels in Saudi patients with kidney disease; and (2) elucidate the other possible physiological factors that may have influence on the vitamin status.

METHODS

A cross-sectional study was carried out in King Khalid Hospital in Hail, Saudi Arabia. The database of kidney disease patients that attended the Kidney Unit between September 2012 and June 2013 was searched and data classified according to the estimated glomerular filtration rate into stages 1-4. Beside the kidney function parameters, serum calcium, phosphorus, vitamin D, and parathyroid hormone were measured.

RESULTS

Out of the 167 patients who visited the kidney unit, the data of 96 patients was included in the study. The results exhibited significant reductions in serum vitamin D level in stage 4 patients by 52.05 per cent with significant increase in the serum PTH level amounting to 3.5-fold. Kidney impairment at stage 4 caused significant increase in the serum phosphate level by 15.74 per cent and the serum calcium by 8.17 per cent. Significant correlations were observed between serum creatinine and Log PTH (r=0.704, p<0.0001) and a negative correlation between creatinine and log vitamin D (r=-0.373, p=0.001).

CONCLUSION

The results exhibited depletion of serum vitamin D concentration accompanied with the development of severe secondary hyperparathyroidism with the progression in kidney disease. The vitamin D deficiency was more prominent in females, older ages, and advanced kidney disease.

Risk of heart failure among postmenopausal women: a secondary analysis of the randomized trial of vitamin D plus calcium of the women's health initiative

BACKGROUND

Vitamin D supplementation may be an inexpensive intervention to reduce heart failure (HF) incidence. However, there are insufficient data to support this hypothesis. This study evaluates whether vitamin D plus calcium (CaD) supplementation is associated with lower rates of HF in postmenopausal women and whether the effects differ between those at high versus low risk for HF.

METHODS AND RESULTS

Analyses were restricted to 35 983 (of original 36 282) women aged 50 to 79 years old in the Women's Health Initiative randomized trial of CaD supplementation who were randomized 1:1 in a double-blinded fashion to receive 1000 mg/d of calcium plus 400 IU/d of vitamin D3 or placebo. Overall, 744 adjudicated incident HF cases (intervention, 363; control, 381) occurred during a median follow-up of 7.1 (interquartile range, 1.6) years. CaD supplementation, compared with placebo, was not associated with reduced HF risk in the overall population, hazard ratio, 0.95; P=0.46. However, CaD supplementation had differential effects (P interaction=0.005) in subgroups stratified by baseline risk status of HF defined by the presence (high risk=17 449) or absence (low risk=18 534) of pre-existing HF precursors including coronary heart diseases, diabetes mellitus, or hypertension: 37% (hazard ratio, 0.63 [95% confidence interval, 0.46-0.87]) lower risk of HF in the low-risk versus hazard ratio, 1.06; P=0.51, in the high-risk subgroups.

CONCLUSIONS

CaD supplementation did not significantly reduce HF incidence in the overall cohort, however, it was beneficial among postmenopausal women without major HF precursors while of little value in high-risk subgroups. Additional studies are warranted to confirm these findings and investigate the underlying mechanism.

CLINICAL TRIAL REGISTRATION URL

http://www.clinicaltrials.gov. Unique identifier: NCT00000611.

Ultraviolet radiation suppresses obesity and symptoms of metabolic syndrome independently of vitamin D in mice fed a high-fat diet

The role of vitamin D in curtailing the development of obesity and comorbidities such as the metabolic syndrome (MetS) and type 2 diabetes has received much attention recently. However, clinical trials have failed to conclusively demonstrate the benefits of vitamin D supplementation. In most studies, serum 25-hydroxyvitamin D [25(OH)D] decreases with increasing BMI above normal weight. These low 25(OH)D levels may also be a proxy for reduced exposure to sunlight-derived ultraviolet radiation (UVR). Here we investigate whether UVR and/or vitamin D supplementation modifies the development of obesity and type 2 diabetes in a murine model of obesity. Long-term suberythemal and erythemal UVR significantly suppressed weight gain, glucose intolerance, insulin resistance, nonalcoholic fatty liver disease measures; and serum levels of fasting insulin, glucose, and cholesterol in C57BL/6 male mice fed a high-fat diet. However, many of the benefits of UVR were not reproduced by vitamin D supplementation. In further mechanistic studies, skin induction of the UVR-induced mediator nitric oxide (NO) reproduced many of the effects of UVR. These studies suggest that UVR (sunlight exposure) may be an effective means of suppressing the development of obesity and MetS, through mechanisms that are independent of vitamin D but dependent on other UVR-induced mediators such as NO.

Vitamin D deficiency and cardiovascular disease: potential mechanisms and novel perspectives

Interest in contemporary vitamin D research has been sparked in recent years, stemming from the identification of vitamin D receptors in virtually all cells as well as the enzymatic machinery necessary to produce its active form. Both epidemiological and in-vitro studies have linked vitamin D deficiency to enigmatic diseases including cardiovascular disease; however, a clear mechanistic link remains missing. This review highlights conclusions of observational studies, in-vitro experiments and randomized-controlled trials that aimed to link deficiency of the sunshine vitamin to one of the leading causes of death in the world, cardiovascular disease. Furthermore, putative mechanisms viewed from a novel perspective are also discussed.

Major electrocardiographic abnormalities and 25-hydroxy vitamin D deficiency: insights from National Health and Nutrition Examination Survey-III

BACKGROUND

We explored the relationship between major electrocardiogram (ECG) abnormalities (mECG) and 25-hydroxy (25-OH) vitamin D deficiency (VDD) and the effect of mECG abnormalities on all-cause and cardiovascular mortality in a healthy cohort with 25-OH vitamin D insufficiency and deficiency.

HYPOTHESIS

Lower levels of serum 25-OH vitamin D are associated with increased prevalence of mECG on resting ECG.

METHODS

We identified 5108 individuals from the National Health and Nutrition Examination Survey-III. mECG abnormalities included: major Q-QS wave abnormalities, ST depression/elevation, negative T waves, Wolff-Parkinson-White pattern, and ventricular conduction defect. Our cohort was divided into 3 groups based on 25-OH vitamin D levels: Group 1 (referent): > 40 ng/mL; group 2 (insufficient): ≥ 20.01 to ≤ 40 ng/mL; and group 3 (deficient): ≤ 20 ng/mL. Logistic regression and Cox proportional hazards regression models were built.

RESULTS

The prevalence of major ECG abnormalities across 25-OH vitamin D sufficiency, insufficiency, and deficiency was .9%, 11%, and 13 %, respectively (P = 0.01). VDD was an independent predictor of mECG abnormalities after adjusting for traditional risk factors (continuous variable odds ratio [OR]: 0.98, 95% confidence interval [CI]: 0.97-0.99, P = 0.007; categorical variable group 3 vs group 1 OR: 2.36, 95% CI: 1.1-5.12, P = 0.03). Baseline major ECG abnormalities were predictive of long-term all-cause (hazard ratio [HR]:1.52, 95% CI: 1.23-1.89), composite cardiovascular (HR: 1.7, 95% CI: 1.34-2.15), cardiovascular (HR: 1.64, 95% CI: 1.27-2.12), and ischemic heart disease mortality (HR: 1.98, 95% CI: 1.46-2.69) in individuals with 25-OH vitamin D levels ≤ 40 ng/mL.

CONCLUSIONS

VDD is associated with increased prevalence of major ECG abnormalities. Well-structured trials are needed to assess progression/resolution of mECG abnormalities with vitamin D supplementation in deficient individuals.

Incidence of Vitamin D Insufficiency in Coastal South-Eastern US Patient Population With Cardiovascular Disease

Background

Vitamin D insufficiency is increasingly gaining prominence as an associated cardiovascular disease (CVD) risk factor, often thought to be an issue in colder climates and higher altitudes. The intent of this study was to ascertain vitamin D levels in the southern Alabama gulf-coast region that has a high number of sunny days along with an annual average elevated UV ray index.

Methods

An observational retrospective study of 204 patients with established CVD treated at the University of South Alabama’s Heart Center from January 2007 through January 2013 was undertaken. One-way ANOVA analyses were performed to determine any significant difference in the mean 25-hydroxyvitamin D (25(OH)D) serum based on gender and also based on race/ethnicity. Further, odds ratio (OR) was computed to ascertain if there was a relationship between vitamin D insufficiency and elevated body mass index (BMI).

Results

Out of 204 patients, 53.4% (n = 109) were found to have vitamin D insufficiency (25(OH)D = 20.1 ng/mL), while 46.6% (n = 95) were within the normal range (25(OH)D = 37.8 ng/mL). The mean 25(OH)D of the entire group was 28.3, indicating a general trend of vitamin D insufficiency for patients treated at the cardiology clinics.

Conclusion

This study established the prevalence of vitamin D insufficiency in the hot and high UV ray index climate of the coastal south-eastern United States. Also, it revealed the relationship of increased BMI with low 25(OH)D serum level. More extensive studies should be conducted in similar climates to further assess vitamin D insufficiency.

Dysregulation of vitamin D metabolism in the brain and myocardium of rats following prolonged exposure to dexamethasone

RATIONALE

Chronic stress or hypercortisolism may increase the risks of depression, cardiac disorders, and osteoporosis, which are also associated with vitamin D (VD) deficiency. Both glucocorticoid receptor (GR) and vitamin D receptor (VDR) are widely distributed and affect many aspects of human physiology. The cross talk between the two steroids is pervasive, but the effect of glucocorticoids on circulating VD and local VD metabolism remains elusive.

OBJECTIVES

To fill this critical gap, we assessed the alterations of circulating VD and VD intracrine system in the brain and myocardium of rats treated with two different doses (0.2 and 2 mg/kg/day, respectively) of dexamethasone (Dex).

RESULTS

Daily treatment with 2 mg/kg of Dex for 10 days induced the rats to a depressive-like state and decreased the expression of both VDR and the cytochromes P450 enzymes involved in VD activation (CYP27B1) and catabolism (CYP24A1) in the prefrontal cortex and hippocampus. Meanwhile, the dose of 0.2 mg/kg Dex increased the expression of VDR in the prefrontal cortex but inhibited CYP27B1/CYP24A1/VDR expression in the hippocampus. Similarly, in the myocardium, the rats treated with Dex showed significantly lower expression of CYP27B1/CYP24A1/VDR. Renal VD metabolism and serum VD status were unchanged in 0.2 mg/kg Dex-treated rats. However, the higher dose suppressed the three key players involved in VD metabolism but did not alter serum VD levels.

CONCLUSION

These data provide new evidence that glucocorticoids could affect intracrine actions of VD in the brain and myocardium, which suggests the potential involvement of VD in the neural and cardiac dysfunctions induced by glucocorticoid excess.

Serum 25-Hydroxyvitamin D Level and Aortic Intima-Media Thickness in Patients Without Clinical Manifestation of Atherosclerotic Cardiovascular Disease

OBJECTIVES

Existing evidence suggests that impaired vitamin D metabolism contribute to the development of atherosclerosis. Aortic intima-media thickness (IMT) is an earlier marker than carotid IMT of preclinical atherosclerosis. However, there is a lack of researches on direct investigation of relevance between serum 25-hydroxyvitamin D (25(OH)D) and thoracic aortic IMT. In this study, we aimed to assess the relationship between thoracic aortic IMT and 25(OH)D.

METHODS

We studied 117 patients (mean age: 45.5 ± 8.4 years) who underwent transesophageal echocardiography (TEE) for various indications. Serum 25(OH)D was measured using a direct competitive chemiluminescent immunoassay. The patients were divided into three groups according to the their serum 25(OH)D levels (VitDdeficiency , VitDinsufficient and VitDnormal groups). TEE was performed in all subjects. High sensitive C-reactive protein (hsCRP) and other biochemical markers were measured using an automated chemistry analyzer.

RESULTS

Only 24.8% (29 patients) of patients had normal levels of 25(OH)D. The highest aortic IMT values were observed in VitDdeficiency group compared with VitDinsufficient and VitDnormal groups (P < 0.05, for all). Also aortic IMT values of VitDinsufficient group were higher than VitDnormal group (P < 0.05). 25(OH)D was independently associated with hs-CRP (β = -0.442, P < 0.001) and aortic IMT (β = -0.499, P < 0.001).

CONCLUSIONS

The lower 25(OH)D level was independently associated with higher aortic IMT values. Therefore, hypovitaminosis D may have a role on pathogenesis of subclinical thoracic atherosclerosis.

Influence of external, intrinsic and individual behaviour variables on serum 25(OH)D in a German survey

The objective of the present study was to identify external, intrinsic or behavioural factors that significantly influenced serum 25-hydroxyvitamin D (25(OH)D) concentrations in a German survey. Data from 3061 participants in the Cooperative Health Research in the Region of Augsburg, Germany (KORA) F4 survey were used to relate potential determinants to measured mean serum 25(OH)D concentrations using multivariable regression models. The factors significantly associated with hypovitaminosis D (defined as 25(OH)D<25 nmolL(-1)) were season (winter, spring and autumn), urban environment and high body mass index. In contrast, times spent in sunny regions, hours per day spent outdoors in the summer as well as additional oral intake were associated with higher 25(OH)D concentrations. These results suggest that mainly ambient UV exposure but also individual behaviour are the most important determinants for personal 25(OH)D concentrations. The analyses further showed that in winter 43% of subjects were vitamin D deficient and 42% insufficient. Even in summer over half the population has insufficient vitamin D status with 8% deficient and 47% insufficient. Therefore measures to mitigate widespread vitamin D insufficiency such as regular short-term sun exposure and/or improved dietary intake/supplementation recommendations by public health bodies need to be considered.

Study of vitamin D deficiency prevalence in acute myocardial infarction

BACKGROUND

Deficiency of 25-hydroxy vitamin D [25(OH)D] is a treatable condition that has been associated with coronary artery disease and many of its risk factors. A practical time to assess for 25(OH)D deficiency, and to initiate treatment, is at the time of an acute myocardial infarction(AMI). The prevalence of 25(OH)D deficiency and the characteristics associated with it in patients with acute myocardial infarction are unknown.

METHODS

In this study 25(OH)D was assessed in 314 subjects enrolled in a Sri Jayadeva Institute of Cardiovascular Science and Research(SJICS&R). Patients enrolled from December 1, 2011 to February 28, 2012 had serum samples sent to a centralized laboratory for analysis using the ELECYS assay. Normal 25(OH)D levels are ≥ 30 ng/ml, and patients with levels < 30 and > 20 ng/ml were classified as insufficient and those with levels ≤ 20 ng/ml as deficient. Vitamin D and other baseline characteristics were analyzed with T-test and chi-squared test.

RESULTS

Of the 314 enrolled patents, 212 (67.5%) were 25(OH)D deficient and 50(16%) were insufficient, for a total of 83.5% of patients with abnormally low 25(OH)D levels. No significant heterogeneity was observed among age or gender sub groups but 25(OH)D deficiency was more commonly seen in those with lower socioeconomic status, lower activity levels, diabetes, hypercholesterolemia(LDL), hypertriglyceridemia and in smokers.

CONCLUSION

Vitamin D deficiency is present in most of the patients with acute myocardial infarction and it is associated with many of its risk factors in our study.

Vitamin D deficiency and cardiovascular events in patients with coronary heart disease: data from the Heart and Soul Study

A growing body of evidence supports an association between vitamin D and cardiovascular disease. However, the mechanisms underlying this association are unknown. From 2000 to 2002, we identified 946 participants with stable cardiovascular disease in San Francisco, California, and followed them prospectively for cardiovascular events (heart failure, myocardial infarction, stroke, or cardiovascular death). We then examined the extent to which the association was attenuated by adjustment for poor health behaviors, comorbid health conditions, and potential biological mediators. During a median follow-up period of 8.0 years (through August 24, 2012), 323 subjects (34.1%) experienced a cardiovascular event. Following adjustment for sociodemographic factors, season of blood measurement, health behaviors, and comorbid conditions, 25-hydroxyvitamin D levels under 20 ng/mL remained independently associated with cardiovascular events (hazard ratio = 1.30, 95% confidence interval: 1.01, 1.67). However, after further adjustment for potential biological mediators, the independent association was no longer present (hazard ratio = 1.11, 95% confidence interval: 0.85, 1.44). Parathyroid hormone, a potentially modifiable biological factor downstream from 25-hydroxyvitamin D, was responsible for the majority of this attenuation. These findings highlight the need for randomized controlled trials to determine whether vitamin D supplementation in persons with deficiency could be beneficial for the primary or secondary prevention of cardiovascular events.

Coexistence of low vitamin D and high fibroblast growth factor-23 plasma levels predicts an adverse outcome in patients with coronary artery disease

Objective

Vitamin D and fibroblast growth factor-23 (FGF-23) are related with cardiovascular disorders. We have investigated the relationship of calcidiol (vitamin D metabolite) and FGF-23 plasma levels with the incidence of adverse outcomes in patients with coronary artery disease.

Methods

Prospective follow-up study of 704 outpatients, attending the departments of Cardiology of four hospitals in Spain, 6–12 months after an acute coronary event. Baseline calcidiol, FGF-23, parathormone, and phosphate plasma levels were assessed. The outcome was the development of acute ischemic events (any acute coronary syndrome, stroke, or transient ischemic attack), heart failure, or death. Cox regression adjusted for the main confounders was performed.

Results

Calcidiol levels showed a moderate-severe decrease in 57.3% of cases. Parathormone, FGF-23, and phosphate levels were increased in 30.0%, 11.5% and 0.9% of patients, respectively. Only 22.4% of patients had glomerular filtration rate<60 ml/min1.73 m². After a mean follow-up was 2.15±0.99 years, 77 patients developed the outcome. Calcidiol (hazard ratio [HR] = 0.67; 95% confidence interval [CI] = 0.48–0.94; p = 0.021) and FGF-23 (HR = 1.13; 95% CI = 1.04–1.23; p = 0.005) plasma levels predicted independently the outcome. There was a significant interaction between calcidiol and FGF-23 levels (p = 0.025). When the population was divided according to FGF-23 levels, calcidiol still predicted the outcome independently in patients with FGF-23 levels higher than the median (HR = 0.50; 95% CI = 0.31–0.80; p = 0.003) but not in those with FGF-23 levels below this value (HR = 1.03; 95% CI = 0.62–1.71; p = 0.904).

Conclusions

Abnormalities in mineral metabolism are frequent in patients with stable coronary artery disease. In this population, low calcidiol plasma levels predict an adverse prognosis in the presence of high FGF-23 levels.

25-hydroxyvitamin D and parathyroid hormone levels do not predict changes in carotid arterial stiffness: the Multi-Ethnic Study of Atherosclerosis

OBJECTIVE

To evaluate the impact of vitamin D and parathyroid hormone (PTH) on longitudinal changes in arterial stiffness.

APPROACH AND RESULTS

Distensibility coefficient and Young's elastic modulus of the right common carotid artery were evaluated at baseline and after a mean (SD) of 9.4 (0.5) years in 2580 Multi-Ethnic Study of Atherosclerosis (MESA) participants. Cross-sectional and longitudinal associations were evaluated using multivariable linear regression and analysis of covariance. At baseline, participants were 60.1 (9.4) years old (54% female; 26% black, 20% Hispanic, 14% Chinese). Mean annualized 25(OH)D was <20 ng/dL in 816 participants, and PTH was >65 pg/dL in 285 participants. In cross-sectional analyses, low 25(OH)D (<20 ng/mL) was not associated with stiffer arteries after adjustment for cardiovascular disease risk factors (P>0.4). PTH >65 pg/mL was associated with stiffer arteries after adjustment for cardiovascular disease risk factors, other than systolic blood pressure (distensibility coefficient: β=-2.4×10(-4) mm Hg(-1), P=0.003; Young's elastic modulus: β=166 mm Hg, P=0.01); however, after adjustment for systolic blood pressure, these associations no longer were statistically significant. Longitudinal arterial stiffening was associated with older age (P<0.0001), higher systolic blood pressure (P<0.008), and use of antihypertensive medications (P<0.006), but not with 25(OH)D or PTH (both P>0.1).

CONCLUSIONS

Carotid arterial stiffness is not associated with low 25(OH)D concentrations. Cross-sectional associations between arterial stiffness and high PTH were attenuated by systolic blood pressure. After nearly a decade of follow-up, neither baseline PTH nor 25(OH)D concentrations were associated with progression of carotid arterial stiffness.

Advances in pathogenesis and current therapeutic strategies for cardiorenal syndrome

Cardiorenal syndrome (CRS) is characterized as a syndrome involving both the cardiovascular system and kidneys. Due to its complexity and high mortality, it has becoming a significant burden and a universal clinical challenge to society worldwide. The mechanisms underlying CRS are potentially multifactorial, including hemodynamic alterations, neurohormonal activation, inflammation, oxidative stress, iron disorders, anemia, and mineral metabolic derangements. Despite the understanding and awareness of CRS gaining attention, appropriate approaches to manage CRS remain deficient. Loop diuretic and thiazides, inhibition of the renin-angiotensin system, vitamin D receptor activation and dopamine and natriuretic peptides could potentially be helpful to improve the prognosis of CRS. Ultrafiltration might be an alternative therapeutic strategy for the loss of liquid. However, adenosine receptor antagonists do not appear to be superior to furosemide in CRS treatment. novel therapeutic approaches should be explored.

Blood vitamin D status and metabolic syndrome in the general adult population: a dose-response meta-analysis

CONTEXT

Increasing evidence has suggested an association between blood vitamin D levels and metabolic syndrome.

OBJECTIVE

Our objective was to determine the relationship between blood vitamin D status and metabolic syndrome in the general adult population, using a dose-response meta-analysis.

DATA SOURCE

We searched the PubMed, EMBASE, Web of Science, and Cochrane Library databases through July 2013 to identify relevant studies.

STUDY SELECTION

Observational studies, reporting risk ratios with a 95% confidence interval (CI) for metabolic syndrome in ≥3 categories of blood 25-hydroxyvitamin D [25(OH)D] levels, were selected.

DATA EXTRACTION

Data extraction was performed independently by 2 authors, and the quality of the studies was evaluated using the risk of bias assessment tool for nonrandomized studies.

DATA SYNTHESIS

The pooled odds ratio of metabolic syndrome per 25 nmol/L increment in the serum/plasma 25(OH)D concentration was 0.87 (95% CI = 0.83-0.92, I(2) = 85%), based on 16 "cross-sectional studies" and 1.00 (95% CI = 0.98-1.02, I(2) = 0%) for 2 "cohort and nested case-control studies." The dose-response meta-analysis showed a generally linear, inverse relationship between 25(OH)D levels and metabolic syndrome in the cross-sectional studies (P for linear trend < .001).

CONCLUSIONS

Blood vitamin D levels were associated with a risk of metabolic syndrome in cross-sectional studies but not in longitudinal studies. Randomized, clinical trials will be necessary to address the issue of causality and to determine whether vitamin D supplementation is effective for the prevention of metabolic syndrome.

Associations of childhood 25-hydroxyvitamin D2 and D3 and cardiovascular risk factors in adolescence: prospective findings from the Avon Longitudinal Study of Parents and Children

BACKGROUND

Studies of the associations of circulating total 25-hydroxyvitamin D (25(OH)D) with cardiovascular disease risk factors in adults have reported inconsistent findings. We aimed to compare prospective associations of two analogues of childhood 25(OH)D (25(OH)D2 and 25(OH)D3) with cardiovascular risk factors measured in adolescence.

METHODS AND RESULTS

We examined associations of childhood (ages 7-12 years) 25(OH)D2 and 25-25(OH)D3 with a range of cardiovascular risk factors (blood pressure, fasting lipids, glucose, insulin and C-reactive protein (CRP)) determined in adolescence (mean age 15.4 years). Data were from 2470 participants of the Avon Longitudinal Study of Parents and Children (ALSPAC), a prospective population-based cohort. After adjustments for age, gender, socioeconomic position and BMI, there were no associations of 25(OH)D2 with cardiovascular risk factors. There was a positive association of season-adjusted (and unadjusted) 25(OH)D3 with high-density lipoprotein cholesterol (HDL-C) (mean change per doubling of 25(OH)D3: 0.03 mmol/l; 95% confidence interval (CI): 0.001 to 0.05, p = 0.02) and an inverse association with fasting insulin (relative difference of -4.59% per doubling; 95% CI: -8.37 to -0.59, p = 0.03). Participants with total 25(OH)D concentration <50 nmol/l had 0.04 mmol/l lower HDL-C (95% CI: -0.07 to -0.01) and 5.54% higher fasting insulin (95% CI: 0.82 to 10.47) compared with participants with total 25(OH)D ≥72 nmol/l.

CONCLUSIONS

In the first prospective study of children/adolescents, we have shown that higher 25(OH)D3 concentrations in childhood are associated with higher levels of HDL-C and lower fasting insulin in adolescence.

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.