Plasma 25-hydroxyvitamin D and its genetic determinants in relation to incident myocardial infarction and stroke in the European prospective investigation into cancer and nutrition (EPIC)-Germany study

A systematic review and meta-analysis of the linkage between low vitamin D and the risk as well as the prognosis of stroke

OBJECTIVE

The research intended to probe the connection between the risk of stroke and serum vitamin D levels.

METHODS

Three electronic databases (Cochrane Library, EMBASE, PubMed) were searched according to the subject terms from inception until July 29, 2022, and retrieved researches were screened on the basis of inclusion and exclusion criteria. Two investigators conducted the quality assessment and data extraction. Using Stata 16.0 software, a meta-analysis was conducted on the extracted data.

FINDINGS

In total, 27 studies with 45,302 participants were included. Among these studies, 20 focused on stroke risk, while 7 examined stroke prognosis. According to the meta-analysis findings, it was observed that a higher stroke risk is connected to reduced levels of serum vitamin D. This association was reflected in a combined relative risk (RR) of 1 .28 (95% confidence interval (CI): 1.15-1.42) and a worse prognosis after stroke (RR = 2.95, 95% CI: 1.90-4.60). Additional analysis indicated that no apparent relationship between a decrease in vitamin D and the probability of experiencing a hemorrhagic stroke was found. The RR found was 1.93 (95% CI: 0.95-3.95). On the other hand, it was observed that a reduction in serum vitamin D levels was linked to an elevated likelihood of developing an ischemic stroke. The RR identified was 1.72 (95% CI: 1.78-2.03). Moreover, a lower level of vitamin D in the bloodstream was associated with a more unfavorable prognosis for individuals who suffered from a stroke. The RR for this correlation was 2.95 (95% CI: 1.90-4.60). However, further research is required to confirm the above-mentioned findings.

CONCLUSION

In conclusion, lower concentration vitamin D was found to be related to an increased risk of stroke, which could mainly be reflected in ischemic stroke patients but not in patients with hemorrhagic stroke. A lower serum vitamin D level was correlative with the poor prognosis of stroke.

From A to E: Uniting vitamins against stroke risk-A systematic review and network meta-analysis

BACKGROUND AND AIM

Stroke represents a significant public health challenge, necessitating the exploration of preventive measures. This network meta-analysis aimed to assess the efficacy of different vitamin treatments compared to a placebo in preventing stroke.

METHODS

A systematic electronic search in databases including PubMed, EmBASE, Web of Science, clinicaltrials.gov, and Google Scholar until 31 May 2023 was conducted, to identify published studies investigating the association between vitamin intake and the risk of stroke. Pooled risk ratio (RR) with 95% confidence intervals (CIs) was calculated using a frequentist network meta-analysis. Furthermore, we ranked vitamins based on p-scores, facilitating a comparative assessment of their effectiveness in preventing stroke.

RESULTS

A total of 56 studies, including 17 randomized controlled trials (RCTs) and 39 cohort studies were analyzed. Direct estimates obtained from network meta-analysis, we found that vitamin A (RR: .81 [.72-.91]), vitamin B-complex (RR: .85 [.74-.97]), vitamin B6 (RR: 79 [.68-.92]), folate (RR: .86 [.75-.97]), vitamin C (RR: .77 [.70-.85]) and vitamin D (RR: .73 [.64-.83]) were significantly associated with a decreased stroke risk. However, no significant association was observed for vitamin B2, vitamin B12, and vitamin E. Subsequent to network meta-analysis, vitamins were ranked in decreasing order of their efficacy in stroke prevention based on p-score, with vitamin D (p-score = .91), vitamin C (p-score = .79), vitamin B6 (p-score = .70), vitamin A (p-score = .65), vitamin B-complex (p-score = .53), folate (p-score = .49), vitamin B2 (p-score = .39), vitamin E (p-score = .28), vitamin B12 (.13) and placebo (.10).

CONCLUSION

Our study has established noteworthy connections between vitamin A, vitamin B-complex, vitamin B6, folate, vitamin C, and vitamin D in the realm of stroke prevention. These findings add substantial weight to the accumulating evidence supporting the potential advantages of vitamin interventions in mitigating the risk of stroke. However, to solidify and validate these observations, additional research is imperative. Well-designed clinical trials or cohort studies are needed to further explore these associations and formulate clear guidelines for incorporating vitamin supplementation into effective stroke prevention strategies.

Vitamin D Supplementation and Cardiovascular Disease Risks in More Than 134000 Individuals in 29 Randomized Clinical Trials and 157000 Individuals in 30 Prospective Cohort Studies: An Updated Systematic Review and Meta-analysis

BACKGROUND

According to the findings from observational studies and clinical trials assessing the effect of vitamin D supplements on cardiovascular diseases (CVDs), there are still contradictory results. This systematic review aimed to assess the effect of vitamin D supplements on CVDs considering cohort studies and clinical trials. Study Design: A systematic review.

METHODS

MEDLINE/PubMed, Science Direct, Embase, and Cochrane Library databases were reviewed by two reviewers independently until 2022. The study effect is risk ratio (RR) and 95% confidence interval (CI) according to Mantel Haenszel's random-effects model. Then, Stata version 14 was used for statistical analysis.

RESULTS

In clinical trial studies, the incidence of CVDs among the vitamin D-consuming group was not significantly different from that in the placebo group (RR: 0.99, 95% CI: 0.95-1.03; P=0.77; I 2=0%). CVD mortality was also not significantly different between the two groups (RR: 0.97, 95% CI: 0.90-1.05; P=0.72; I2=0%). In cohort studies, circulating 25 (OH) D increased the risk of CVD incidence by 31% (RR: 1.31, 95% CI: 1.19-1.45) and CVD mortality by 37% (RR: 1.37, 95% CI: 1.17-1.61).

CONCLUSION

According to current evidence from clinical trials, vitamin D supplementation should not be recommended for CVD prevention. However, there is a direct association between vitamin D deficiency and the incidence of CVDs as well as its mortality. According to the results of clinical trial studies carrying higher levels of scientific evidence, it can be concluded that vitamin D supplementation does not exert a significant effect on the incidence, mortality, and reduction of CVDs.

Low serum 25-hydroxyvitamin D levels are associated with increased cardiovascular morbidity and mortality

BACKGROUND

There is controversy about the association between vitamin D and cardiovascular disease (CVD). This article aims to explore the association of serum 25-hydroxyvitaminD (25 OHD) with the risk of CVD.

METHODS

PubMed, EMBASE, Web of Science database, OVID, and Cochrane Library databases (last updated in August 2022) were systematically searched. The relationship between 25OHD and the risk of CVD was assessed by using the 95% confidence intervals (CI) and hazard ratio (HR). The effect model was selected by the size of heterogeneity.

RESULTS

The meta-analysis included 40 cohort studies that contained 652352 samples. The pooled results showed that a decreased level of 25OHD was associated with an increased relative risk of total CVD events (HR = 1.35, 95% CI: 1.26-1.43). Furthermore, the results also showed that a decreased circulating 25OHD level was associated with an increased mortality of CVD (HR = 1.43, 95% CI: 1.30-1.57) and incidence of CVD (HR = 1.26, 95% CI: 1.16-1.36), especially an increased risk of heart failure (HF) (HR = 1.38, 95% CI: 1.2-1.6), myocardial infarction (MI) (HR = 1.28, 95% CI: 1.13-1.44) and coronary heart disease (CHD) (HR = 1.28, 95% CI: 1.1-1.49).

CONCLUSIONS

The current meta-analysis shows that reduced serum 25OHD concentrations is not only associated with increased total cardiovascular events and cardiovascular mortality, but also with increased risk of HF, MI, and CHD.

LIMITATIONS

The underlying mechanism still needs to be explored further, and well-designed RCTs are needed to confirm the role of vitamin D in the occurrence and development of CVD.

Vitamin D serum level predicts stroke clinical severity, functional independence, and disability—A retrospective cohort study

Background

Stroke is a leading cause of mortality and disability and one of the most common neurological conditions globally. Many studies focused on vitamin D as a stroke risk factor, but only a few focused on its serum level as a predictor of stroke initial clinical severity and recovery with inconsistent results. The purpose of this study was to assess the relationship between serum vitamin D levels and stroke clinical severity at admission and functional independence and disability at discharge in Saudi Arabia.

Methodology

A retrospective cohort study of adult ischemic stroke patients who had their vitamin D tested and admitted within 7 days of exhibiting stroke symptoms at King Abdulaziz Medical City (KAMC) Jeddah, Saudi Arabia. Based on vitamin D level, the patients were categorized into normal [25(OH)D serum level ≥ 75 nmol/L], insufficient [25(OH)D serum level is 50–75 nmol/L], and deficient [25(OH)D serum level ≤ 50 nmol/L]. The primary outcome was to assess the vitamin D serum level of ischemic stroke patients’ clinical severity at admission and functional independence at discharge. The National Institute of Health Stroke Scale (NIHSS) was used to assess the clinical severity, whereas the modified Rankin scale (mRS) was used to assess functional independence and disability.

Results

The study included 294 stroke patients, out of 774, who were selected based on the inclusion and exclusion criteria. The mean age of the participants was 68.2 ± 13.4 years, and 49.3% were male. The patients’ distribution among the three groups based on their vitamin D levels is: normal (n = 35, 11.9%), insufficient (n = 66, 22.5%), and deficient (n = 196, 65.6%). After adjusting for potential covariates, regression analysis found a significant inverse relationship of NIHSS based on 25(OH)D serum level (beta coefficient: −0.04, SE: 0.01, p = 0.003). Patients with deficient serum vitamin D level also had significantly higher odds of worse functional independence in mRS score [OR: 2.41, 95%CI: (1.13–5.16), p = 0.023] when compared to participants with normal vitamin D level.

Conclusion

Low vitamin D levels were associated with higher severity of stroke at admission and poor functional independence and disability at discharge in patients with acute ischemic stroke. Further randomized clinical and interventional studies are required to confirm our findings.

Circulating 25-hydroxy-vitamin D and the risk of cardiovascular diseases. Systematic review and meta-analysis of prospective cohort studies

AIMS

Circulating vitamin D is linked with the risk of cardiovascular disease (CVD). A meta-analysis has yet to explicitly explore correlation between vitamin D and the risk of CVD incidence and recurrent CVD. This meta-analysis examines the association between 25-hydroxy-vitamin D (25(OH)D) and the risk of CVD incidence (fatal, non-fatal, fatal and non-fatal combined events) and the risk of recurrent CVD (fatal, recurrent, and fatal and recurrent combined events). PROSPERO registration-CRD42021251483.

DATA SYNTHESIS

A total of 79 studies (46 713 CVD cases in 1 397 831 participants) were included in the meta-analysis, of which 61 studies examined the risk of CVD incidence events, and 18 studies examined risk of recurrent CVD events. The risk of CVD incidence events (RR = 1.34, 95% CI: 1.26-1.43, p < 0.001) and recurrent CVD events (RR = 1.86, 95% CI: 1.46-2.36, p < 0.001) was higher in the lowest than the highest category of circulating 25(OH)D. Dose-response analysis reported a linear association for every 10 ng/ml increment of 25(OH)D and non-fatal CVD incidence events (RR = 0.94; 95% CI = 0.89-0.98, p = 0.005), lower fatal recurrent CVD events (RR = 0.45; 95% CI = 0.32-0.62, p < 0.001) and lower combined recurrent CVD events (RR = 0.80; 95% CI = 0.65-0.97, p = 0.023). A non-linear association was observed between higher 25(OH)D and lower fatal CVD incidence events (P-nonlinear<0.001), lower combined CVD incidence events (P-nonlinear = 0.001), and lower non-fatal recurrent CVD events (P-nonlinear = 0.044).

CONCLUSIONS

The lowest category of circulating 25(OH)D was associated with a higher risk of CVD incidence events and recurrent CVD events.

Association between Vitamin D and Risk of Stroke: A PRISMA-Compliant Systematic Review and Meta-Analysis

BACKGROUND

Previous studies have shown inconsistent results for associations between vitamin D and risk of stroke. We gathered the existing published articles and conducted this meta-analysis with the aim to explore the association between vitamin D and risk of stroke.

METHODS

We searched for articles exploring the association between vitamin D and risk of stroke and published before April 2021 in the following databases: PubMed, Web of Science, MEDLINE, EMBASE, and Google Scholar. All statistical analyses were made using STATA 12.0 software. Q test and I2 were applied to examine heterogeneities between studies.

RESULTS

For the association between serum levels of 25(OH) vitamin D and risks of stroke, the present analysis included 20 cohort studies (including 213,276 participants) and a case-control analysis (including 13,642 participants). Additionally, the analysis included 15 studies (including 41,146 participants given vitamin D supplementation and 41,163 participants given placebo) to evaluate the influence of vitamin D supplementation on risk of stroke. Higher circulating levels of 25(OH) vitamin D were associated with a reduced risk of stroke (odds ratio/relative risk = 0.78, 95% confidence interval [CI]: 0.70-0.86, I2 = 41.5%, p = 0.025). However, the present analysis showed that vitamin D supplementation did not influence the risk of stroke (hazard ratio = 1.05, 95% CI: 0.96-1.14, I2 = 2.3%, p = 0.425).

CONCLUSIONS

Our analysis indicated that lower circulating level of vitamin D was associated with an elevated risk of stroke, but extra supplement of vitamin D failed to show benefit in decreasing the risk of stroke. Further research and study are also needed to show the role of vitamin D in relation to stroke.

An intronic DHCR7 genetic polymorphism associates with vitamin D serum level and incidence of acute coronary syndrome

INTRODUCTION

Vitamin D deficiency has been linked to cardiovascular pathologies including acute coronary syndrome (ACS). Polymorphisms in vitamin D associated genes have been confounding to vitamin D serum levels and pathological predispositions. 7-hydrocholesterol is a common precursor in cholesterol and vitamin D synthesis. DHCR7/NADSYN1 genetic locus expresses 7-hydrocholesterol reductase (DHCR7), an enzyme that recruits 7-hydrocholesterol in cholesterol biosynthesis, and NAD synthetase 1 (NADSYN1), which participates in the hydroxylation of 25 hydroxyvitamin D.

AIM

This study aims to correlate two polymorphisms in the DHCR7/NADSYN1 genetic locus with levels of circulatory vitamin D and the presentation of ACS in an Egyptian population.

METHODS

In a case control study, 189 ACS patients and 106 healthy control subjects were genotyped for SNPs rs11606033 of the DHCR7 gene and rs2276360 of the NADSYN1 gene using the amplification-refractory mutation system (ARMS). The levels of 25(OH)D2 and 25(OH)D3 were measured using an in-house developed and validated ultra-performance liquid chromatography tandem mass spectrometry (UPLC-MS/MS) based protocol.

RESULTS

ACS patients have significantly lower levels of circulating vitamin D in comparison to healthy controls. Allele A of the DHCR7 polymorphism was found to correlate with serum vitamin D deficiency and incidence of ACS classes: NSTEMI, STEMI and unstable angina, when compared to allele G. On the other hand, the NADSYN1 polymorphism rs2276360 correlated with serum 25(OH)D3 deficiency. Yet, no significant correlation was found with incidences of ACS.

CONCLUSION

We conclude that rs11606033, which is an intronic SNP between exon 4 and exon 5 of the DHCR7 gene, influences vitamin D serum abundance and more importantly ACS incidence.

The Relationship of Vitamin D Deficiency with Severity and Outcome of Acute Stroke

Background: There are currently conflicting results regarding the link between vitamin D deficiency and increased risk for stroke and its poor prognosis. The present study aimed to assess the relationship between vitamin D deficiency and prognosis of acute stroke.Methods: This bi-center cross-sectional study was performed on 140 consecutive patients who referred to two general hospitals in Iran with the diagnosis of acute stroke. The levels of 25-hydroxy vitamin D were evaluated by Electrochemiluminescence (ECL) technique. Clinical severity of stroke on admission as well as on discharge time were evaluated using the National Institutes of Health Stroke Scale (NIHSS) or Modified Rankin (mRS) tools.Results: Mean serum level of vitamin D was 25.51 ± 18.87 ng/mL, ranging from 3.0 to 98.6 ng/ml. There was a significant difference between the two groups (with and without vitamin D deficiency) in terms of stroke severity and disability, as reflected by mRS (P=0.003) and NIHSS evaluation (14.24 ± 9.23 versus 9.73 ± 7.36, P=0.003). Also, regarding patients' clinical condition, the mean NIHSS score in those with deficient and normal levels of vitamin D was 14.24 ± 9.23 and 9.73 ± 7.36, respectively with NIHSS score > 5 in 76.1% and 61.5%, respectively (P = 0.003).Conclusion: According to the results of study, vitamin D status can be related to the severity of stroke. However, considering the cross-sectional design of our study, it could not point out the causality between vitamin D deficiency and acute stroke and further studies are warranted. It is not possible to draw any conclusions in terms of causality. Further studies are required in order to assess the relationship between the serum vitamin D levels and stroke severity.

The Role of Polymorphisms in Vitamin D-Related Genes in Response to Vitamin D Supplementation

Background. Vitamin D deficiency represents a major healthcare problem. Vitamin D status is influenced by genetic and environmental determinants. Several observational studies have evaluated the association of single-nucleotide polymorphisms (SNPs) in vitamin D-related genes and vitamin D levels. Nevertheless, little is known about the role of these SNPs in the response to vitamin D supplementation. We conducted an interventional study to define the association between SNPs in vitamin D-related genes and the response to vitamin D supplementation in 100 self-reported healthy women of Arab ancestry for the majority. Methods. A total of 100 healthy female subjects received a weekly oral dose of 50,000 IU vitamin D for 12 weeks. Serum vitamin D concentration and metabolic profiles were measured at baseline and 12 weeks post-vitamin D supplementation. The genotypes of 37 SNPs selected from previously reported vitamin D-related genes have been assessed by Fluidigm genotyping assay. Results. Rs731236 (VDR gene) and rs7116978 (CYP2R1 gene) showed a significant association with vitamin D status. The rs731236 GG genotype and the rs7116978 CC genotype were associated with a “vitamin D sufficiency” state. Rs731236 GG and rs7116978 CC genotypes showed a higher response to vitamin D supplementation. Transcription factor binding site prediction analysis showed altered binding sites for transcription factors according to the different rs7116978 alleles. Interestingly, the 37 SNPs previously established to play a role in vitamin D-related pathways explained very little of the response to vitamin D supplementation in our cohort, suggesting the existence of alternative loci whose number and effect size need to be investigated in future studies. Conclusion. In this paper, we present novel data on vitamin D-related SNPs and response to vitamin D supplementation demonstrating the feasibility of applying functional genomic approaches in interventional studies to assess individual-level responses to vitamin D supplementation.

Genetic Variation in Cytochrome P450 2R1 and Vitamin D Binding Protein Genes are associated with Vitamin D Deficiency in Adolescents

Background: Genome Wide Association Studies (GWAS) have evaluated several genes related to vitamin D synthesis, metabolism and transport. They have proposed a genetic basis for low levels of vitamin D in the blood. The current study aims to investigate the relationship between certain vitamin D-associated gene variants and vitamin D deficiency in Iranian adolescents. Methods: In this case-control study, the genomic DNA was extracted by Real Time PCR High Resolution Melt (HRM). All measurements were carried out with triple repetition. The following factors were assessed: single nucleotide polymorphisms (SNPs) in Vitamin D binding protein (DBP, rs2282679), 7-Dehydrocholesterol reductase (DHCR7, rs12785878) and Cytochrome P450 2R1 (CYP2R1, rs10741657). Results: the genomic DNA of blood samples obtained from 481 adolescents. Participants with hypovitaminosis D were compared with a control group. The average vitamin D level of sufficient subjects (controls) was 44.88±14.01 ng/mL, while subjects who were insufficient (cases) had an average vitamin D level of 7.03±1.24 ng/mL. No statistically significant differences were found in the allelic and genotypic distributions between genders. The SNP frequency in CYP2R1 (rs10741657) and DBP (rs2282679) in the vitamin D deficient group was significantly higher than in the control group (p-values < 0.001 and 0.01 respectively). There were no statistically significant differences in the DHCR7 SNP (rs12785878) distributions between the Vitamin D deficient group and control group. Conclusion: The present study demonstrated evidence of the ability of the SNPs under investigation to predict circulating vitamin D concentration. Further study is needed to better understand if and how genetic factors contribute to vitamin D levels, and certain skeletal-associated disorders in adolescents.

Vitamin D and Stroke: Effects on Incidence, Severity, and Outcome and the Potential Benefits of Supplementation

Vitamin D serum level has been positively associated with improved cardiovascular health, especially with reduction of stroke risk. This systemic review summarizes and synthesizes findings from studies relevant to the relationship between vitamin D and stroke risk, severity, and outcome; potential mechanisms explaining such a relationship; and outcomes from vitamin D supplementation. The literature shows that vitamin D deficiency is a significant risk factor for ischemic stroke, with sun exposure, sex, age, race, diabetes, and genetics playing a role as well. Stroke severity and short- and long-term outcomes also worsen with vitamin D deficiency. The neuroprotective mechanisms by which vitamin D operates to mitigate stroke onset and outcomes have yet to be fully studied, but researchers have proposed several pathways, including promotion of certain neuroprotective growth factors, reduction of arterial pressure through vasodilation, and inhibition of reactive oxygen species. There is some evidence that vitamin D supplementation could lower stroke risk and improve recovery, though outcomes can also be negligible or negative. Although results are mixed and the limitations of vitamin D supplementation merit some caution, vitamin D overall plays a significant role in stroke health. Future research should further develop understanding of the neuroprotective mechanisms of vitamin D and study how supplementation could be administered effectively in stroke treatment.

Vitamin D and Rehabilitation after Stroke: Status of Art

Stroke is the first cause of disability in the population and post-stroke patients admitted to rehabilitation units often present a malnutrition status which can influence nutritional indices and then vitamin levels. Vitamin D deficiency seems implicated beyond stroke severity and stroke risk, and also affects post-stroke recovery. Some studies on vitamin D levels and outcome in stroke patients are available but very few data on vitamin D levels and outcome after rehabilitation treatment are reported. This literature review shows the possible relationship between vitamin D deficiency and recovery in post-stroke patients undergoing rehabilitation treatment. Moreover, because several studies have reported that single nucleotide polymorphisms and promoter methylation in genes are involved in vitamin D metabolism and might affect circulating vitamin D levels, these aspects are evaluated in the current paper. From the studies evaluated in this review, it emerges that vitamin D deficiency could not only have an important role in the recovery of patients undergoing rehabilitation after a stroke, but that genetic and epigenetic factors related to vitamin D levels could have a crucial role on the rehabilitation outcome of patients after stroke. Therefore, further studies are necessary on stroke patients undergoing rehabilitation treatment, including: (a) the measurement of the 25(OH) vitamin D serum concentrations at admission and post rehabilitation treatment; (b) the identification of the presence/absence of CYP2R1, CYP27B1, CYP24A1 and VDR polymorphisms, and (c) analysis of the methylation levels of these genes pre- and post-rehabilitation treatment.

The association between circulating 25-hydroxyvitamin D and cardiovascular diseases: a meta-analysis of prospective cohort studies

BACKGROUND

There is a controversy about the association between vitamin D and cardiovascular diseases (CVDs). The effect of serum 25-OH-vitD on the risk of CVDs was evaluated.

METHODS

Major electronic databases including Scopus, Science Direct, and PubMed were searched. All prospective cohort studies on the relationship between vitamin D status and CVDs conducted between April 2000 and September 2017 were included, regardless language. The study participants were evaluated regardless of their age, sex, and ethnicity. The Newcastle-Ottawa Scale was used to assess the quality of the studies. Two investigators independently selected the studies and extracted the data. The designated effects were risk ratio (RR) and hazard ratio (HR). The random effects model was used to combine the results.

RESULTS

A meta-analysis of 25 studies with 10,099 cases of CVDs was performed. In general, a decrease in the level of vitamin D was associated with a higher relative risk of CVDs (incidence-mortality combined) (RR = 1.44, 95% CI: 1.24-1.69). This accounts for 54% of CVDs mortality rate (RR = 1.54, 95% CI: 1.29-1.84(. However, no significant relationship was observed between the vitamin D status and incidence of CVDs (RR = 1.18, 95% CI: 1-1.39). In general, low serum vitamin D level increased the risk of CVD by 44% (RR = 1.44, 95% CI: 1.24-1.69). It also increased the risk of CVD mortality (RR = 1.54, 95% CI: 1.29-1.84) and incidence rates (RR = 1.18, 95% CI: 1-1.39).

CONCLUSIONS

The findings showed that vitamin D deficiency increases the CVDs mortality rate. Due to the limited number of studies on patients of the both genders, further research is suggested to separately evaluate the effect of vitamin D status on CVD in men and women.

Vitamin D and cardiovascular disorders

Vitamin D is necessary for bone health but may also have many extra-skeletal effects. The vitamin D endocrine system has major effects on gene and protein expression in many cells and tissues related to the cardiovascular system. In addition, many preclinical studies in animals with vitamin D deficiency or genetically silenced expression of the vitamin D receptor or vitamin D metabolizing enzymes suggest that the absence of vitamin D action may result in cardiovascular events. This includes dysfunctions of endothelial cells, thereby accelerating the process of atherosclerosis, hypertension or abnormal coagulation, ultimately resulting in higher risks for all major cardiovascular or cerebrovascular events. A wealth of observational studies in different parts of the world have fairly consistently found a strong association between a poor vitamin D status and surrogate markers or hard cardiovascular events. A few Mendelian randomization studies did, however, not find a link between genetically lower serum 25OHD concentrations and cardiovascular events. Finally, many RCTs could not demonstrate a consistent effect on surrogate markers, and a limited number of RCTs did so far not find whatever effect on hard cardiovascular endpoints such as myocardial ischemia or infarction, stroke, or cardiovascular death. In conclusion, preclinical data generated a plausible hypothesis of a link between vitamin D status and extra-skeletal events, including cardiovascular endpoints. Whether the vitamin D endocrine system is redundant for the human vascular system or whether the RCTs have not been optimally designed to answer the research question is thus not yet settled.

Depressed Serum 25-Hydroxyvitamin D Levels Increase Hospital Stay and Alter Glucose Homeostasis in First-ever Ischemic Stroke

BACKGROUND AND OBJECTIVE

Vitamin D deficiency is internationally recognized among the potentially modifiable risk factors for ischemic cardio-cerebrovascular diseases. However, the association between vitamin D deficiency and stroke morbidity or mortality remains insufficiently known. Our aim is to investigate their relevance to 25-hydroxyvitamin D [25(OH) D] levels and clinical severity and outcome after 3 months in first-ever ischemic stroke.

METHODS

Retrospective analysis of 356 consecutive patients in first-ever ischemic stroke between 2013 and 2015. Serum 25(OH) D levels were measured at baseline. Stroke severity was assessed at admission using the National Institutes of Health Stroke Scale (NIHSS) score. Functional outcome after 3 months of onset was evaluated using the modified Rankin scale (mRS).

RESULTS

Among the 356 enrolled patients, HbA1c was higher in insufficiency/deficiency group than that in the sufficiency group (6.3 ± 1.7 vs. 5.9 ± 1.1, p =0.015). The hospital stay was longer in insufficiency/deficiency group than that in the sufficiency group (11 (8-17) vs. 9.5 (7-13), p = 0.035). There was a significant inversed trend between serum 25(OH) D levels and hospital stay (OR 0.960, P = 0.031), using logistic regression.

CONCLUSION

25(OH)D levels are associated with glucose homeostasis, 25(OH) D contributes to increase the length of hospital stay. Low serum 25-OHD level is an independent predictor for hospital stay in first-ever ischemic stroke. Vitamin D deficiency did not predict functional outcome in the span of 3 months.

25-Hydroxyvitamin D level, vitamin D intake, and risk of stroke: A dose-response meta-analysis

BACKGROUND & AIMS

A growing number of studies have shown that vitamin D are related to the risk of stroke, however, the dose-response association between vitamin D and the risk of stroke is still unclear. Accordingly, we conducted a dose-response meta-analysis to evaluate the relationships between 25-hydroxyvitamin D [25(OH)D] level, vitamin D intake, and the risk of stroke by summarizing cohort studies.

METHODS

PubMed, Embase, Cochrane and the Web of Science database were searched for related studies. Cohort studies examining the influence of 25(OH)D level and vitamin D intake on stroke risk were summarized. Dose-response relationships were determined using a random-effect model.

RESULTS

Twenty cohort studies involving 217,235 participants were included. The pooled relative risk for the high-versus-low categories was 0.74 (95% CI: 0.66-0.83) for 25(OH)D level, and 0.75 (95% CI: 0.57-0.98) for vitamin D intake. In addition, there were non-linear relationships between 25(OH)D level, vitamin D intake, and stroke risk. The incidence of stroke was reduced to its lowest point, with a reduction of about 20%, when 25(OH)D level was about 50 nmol/L or vitamin D intake was about 12 μg/day.

CONCLUSION

25(OH)D level and vitamin D intake were both inversely related to stroke risk, with a non-linear dose-response relationship.

Plasma 25-Hydroxyvitamin D and Mortality in Patients With Suspected Stable Angina Pectoris

CONTEXT AND OBJECTIVE

Vitamin D status may affect cardiovascular disease (CVD) development and survival. We studied the relationship between concentrations of the circulating biomarker 25-hydroxyvitamin D (25OHD) and all-cause and cardiovascular mortality risk.

DESIGN, SETTING, PARTICIPANTS, AND MAIN OUTCOME MEASURES

25OHD, the sum of 25-hydroxyvitamin D3 and 25-hydroxyvitamin D2, was analyzed in plasma samples from 4114 white patients suspected of having stable angina pectoris and was adjusted for seasonal variation. Hazard ratios (HRs) for all-cause and cardiovascular mortality were estimated by using multivariable Cox models with 25OHD as the main exposure variable, with adjustment for study site, age, sex, smoking, body mass index, estimated glomerular filtration rate, and systolic blood pressure.

RESULTS

A total of 895 (21.8%) deaths, including 407 (9.9%) from CVD causes, occurred during a mean ± standard deviation follow-up of 11.9 ± 3.0 years. Compared with the first 25OHD quartile, HRs in the second, third, and fourth quartiles were 0.64 [95% confidence interval (CI), 0.54 to 0.77], 0.56 (95% CI, 0.46 to 0.67), and 0.56 (95% CI, 0.46 to 0.67) for all-cause mortality and 0.70 (95% CI, 0.53 to 0.91), 0.60 (95% CI, 0.45 to 0.79), and 0.57 (95% CI, 0.43 to 0.75) for cardiovascular mortality, respectively. Threshold analysis demonstrated increased all-cause and CVD mortality in patients with 25OHD concentrations below ∼42.5 nmol/L. Moreover, analysis suggested increased all-cause mortality at concentrations >100 nmol/L.

CONCLUSION

Plasma 25OHD concentrations were inversely associated with cardiovascular mortality and nonlinearly (U-shaped) associated with all-cause mortality.

Lower Vitamin D Status Is Associated with an Increased Risk of Ischemic Stroke: A Systematic Review and Meta-Analysis

In recent years, accumulating evidence has supported the hypothesis that lower vitamin D status is associated with several known risk factors of stroke. However, the relationship between vitamin D and stroke is still uncertain. To explore if there was an association between vitamin D status and the risk of stroke, a systematic review and a meta-analysis were conducted by searching three databases: Pubmed, Embase, and the Cochrane Library. Following the application of inclusion and exclusion criteria, the relative risk estimates of all the included studies were pooled together to compare the risk of stroke between the lowest and the highest category of vitamin D. The Newcastle-Ottawa Scale (NOS) and the Cochrane Risk of Bias Tool were used to assess the risk of bias, and the publication bias was detected by using a funnel plot and Egger's test. Nineteen studies were included and the pooled relative risk was 1.62 (95% CI: 1.34-1.96). Further analysis found that vitamin D status was associated with ischemic stroke (relative risk = 2.45, 95% CI: 1.56-3.86), but not with hemorrhagic stroke (relative risk = 2.50, 95% CI: 0.87-7.15). In conclusion, our meta-analysis supported the hypothesis that lower vitamin D status was associated with an increased risk of ischemic stroke. Further studies are required to confirm this association and to explore the association among different subtypes.

Serum 25-hydroxyvitamin D and the risk of stroke in Hong Kong Chinese

Low vitamin D levels have been associated with various cardiovascular diseases; however, whether it is associated with stroke remains inconclusive. We aimed to evaluate the association between serum 25-hydroxyvitamin D and risk of stroke. We conducted a cohort study consisting of 3,458 participants from the Hong Kong Osteoporosis Study aged ≥45 at baseline, examined between 1995 and 2010 and followed up using electronic medical records. Ischaemic and haemorrhagic stroke were defined using the ICD-9 code. In multivariable Cox-proportional hazard regression, quintiles 1 and 4 were significantly associated with increased risk of stroke when compared to the highest quintile (Quintile 1: HR, 1.78; 95 % CI, 1.16–2.74 and quintile 4: HR, 1.61; 95 % CI, 1.07–2.43). A similar association was observed in both men and women. In subgroup analysis, the association was specifically observed for ischaemic stroke, but not haemorrhagic stroke. Using a penalized regression spline, the association between vitamin D and risk of stroke was in a reverse J-shape, with the lowest risk of stroke being observed at 25(OH)D levels between 70 and 80 nmol/l. In conclusion, a low vitamin D level is associated with increased risk of ischaemic stroke; however, whether high vitamin D level is also associated with increased risk of stroke requires further study.

Supplementary Material to this article is available at www.thrombosis-online.com.

Independent assortment of GC gene polymorphism (rs2282679) and 25-hydroxyvitamin D levels in coronary artery disease

Coronary artery disease (CAD) remains a major public health burden. Emerging research has suggested an association between vitamin D insufficiency and CAD. Vitamin D binding protein (VDBP) is the primary vitamin D carrier and many of its genetic polymorphisms are able to induce the expression of proteins with different affinities for the vitamin, which in turn might affect its serum levels and CAD incidence. One hundred and twelve male patients, aged between 35 and 50 years, with verified CAD and 109 age- and sex-matched controls were recruited. Genotyping was performed by the TaqMan allelic discrimination assay and plasma 25(OH)D levels were assessed by HPLC-UV. Serum parathyroid hormone (s-PTH) and VDBP levels were measured using ELISA. s-25(OH)D levels in CAD patients were significantly lower than in the controls, whereas s-PTH levels were significantly higher in the CAD patients than in the controls. There was no significant difference in the distribution of GC genotypes among both groups. s-25(OH)D showed a weak inverse correlation with s-PTH levels. Serum levels of vitamin D and PTH are highly correlated with CAD incidence. However, the s-VDBP level is associated neither with disease outcome nor with vitamin D status. The GC gene variant has no effect on 25(OH)D levels.

Vitamin D intake and risk of CVD and all-cause mortality: evidence from the Caerphilly Prospective Cohort Study

Objective

Prospective data on the associations between vitamin D intake and risk of CVD and all-cause mortality are limited and inconclusive. The aim of the present study was to investigate the associations between vitamin D intake and CVD risk and all-cause mortality in the Caerphilly Prospective Cohort Study.

Design

The associations of vitamin D intake with CVD risk markers were examined cross-sectionally at baseline and longitudinally at 5-year, 10-year and >20-year follow-ups. In addition, the predictive value of vitamin D intake for CVD events and all-cause mortality after >20 years of follow-up was examined. Logistic regression and general linear regression were used for data analysis.

Setting

Participants in the UK.

Subjects

Men (n452) who were free from CVD and type 2 diabetes at recruitment.

Results

Higher vitamin D intake was associated with increased HDL cholesterol (P=0·003) and pulse pressure (P=0·04) and decreased total cholesterol:HDL cholesterol (P=0·008) cross-sectionally at baseline, but the associations were lost during follow-up. Furthermore, higher vitamin D intake was associated with decreased concentration of plasma TAG at baseline (P=0·01) and at the 5-year (P=0·01), but not the 10-year examination. After >20 years of follow-up, vitamin D was not associated with stroke (n72), myocardial infarctions (n142), heart failure (n43) or all-cause mortality (n281), but was positively associated with increased diastolic blood pressure (P=0·03).

Conclusions

The study supports associations of higher vitamin D intake with lower fasting plasma TAG and higher diastolic blood pressure.

Genetic variants underlying vitamin D metabolism and VDR-TGFβ-1-SMAD3 interaction may impact on HCV progression: a study based on dbGaP data from the HALT-C study

Vitamin D deficiency is prevalent in liver disease and vitamin D has been shown to decrease hepatic fibrosis through an anti-TGFβ-1/SMAD3 effect mediated by the vitamin D receptor. Thus, we hypothesized that genetic variants involved in vitamin D metabolism and/or VDR/TGFβ-1/SMAD3 interaction could impact on the progression of chronic HCV. We obtained or imputed genotypes for 40 single nucleotide polymorphisms (SNPs) located in genes implicated in vitamin D metabolism from the HALT-C cohort via dbGaP. The HALT-C study followed 692 chronic HCV patients over 4 years, evaluating clinical outcomes including worsening of fibrosis, hepatic decompensation (gastric/esophageal bleeding, CTP>7, ascites, spontaneous bacterial peritonitis and encephalopathy), development of hepatocellular carcinoma, and liver death. We tested the selected SNPs for association with these outcomes in 681 HALT-C subjects. Eleven SNPs presented tendency towards significance (P<0.05): four SNPs in DHCR7 related to with hepatic decompensation (rs4944957, rs12800438, rs3829251 and rs4945008); two in GC to worsening of fibrosis and liver death (rs7041 and rs222020); two in CYP2R1 to ascites and hepatocellular carcinoma (rs7116978 and rs1562902); two in VDR to gastric/esophageal bleeding and hepatocellular carcinoma (rs4516035 and rs2239186); and one in SMAD3 to worsening of fibrosis and encephalopathy (rs2118610). Only rs1800469 in TGFB1 was statistically associated with hepatic decompensation after Bonferroni's correction (P<0.00125). In conclusion, rs1800469 in TGFB1 was associated to hepatic decompensation in chronic hepatitis C, while the other 11 described polymorphisms must be evaluated in a larger cohort to determine the possible role of vitamin D in hepatitis C.

Serum 25-hydroxyvitamin D and the risk of cardiovascular disease: dose-response meta-analysis of prospective studies

Background: During the past decade, an increasing number of prospective studies have focused on the association between vitamin D and cardiovascular disease (CVD). However, the evidence on the relation between serum 25-hydroxyvitamin D [25(OH)D] and the risk of overt CVD is inconclusive.Objective: We performed a dose-response meta-analysis to summarize and prospectively quantify the RR of low serum 25(OH)D concentration and total CVD (events and mortality).Design: We identified relevant studies by searching PubMed and EMBASE up to December 2015 and by hand-searching reference lists. Prospective studies based on the general population and reported RRs and 95% CIs were included. A random-effects model was used to calculate the pooled RRs. Nonlinear association was assessed by using restricted cubic spline analyses.Results: A total of 34 publications with 180,667 participants were eligible for the meta-analysis. We included 32 publications (27 independent studies) for total CVD events and 17 publications (17 independent studies) for CVD mortality. We observed an inverse association between serum 25(OH)D and total CVD events and CVD mortality, and the pooled RRs per 10-ng/mL increment were 0.90 (95% CI: 0.86, 0.94) for total CVD events and 0.88 (95% CI: 0.80, 0.96) for CVD mortality. A nonlinear association was detected for total CVD events (P-nonlinear < 0.001) and CVD mortality (P-nonlinear = 0.022).Conclusion: Serum 25(OH)D concentration was inversely associated with total CVD events and CVD mortality from the observed studies.

Vitamin D deficiency is associated with acute ischemic stroke, C-reactive protein, and short-term outcome

The aim of this study was to investigate whether vitamin D deficiency (VDD) is associated with acute ischemic stroke, inflammatory markers, and short-term outcome. 168 acute ischemic stroke patients and 118 controls were included. The modified Rankin Scale (mRS) was applied up to 8 h of admission (baseline) and after three-months follow-up, and blood samples were obtained up to 24 h of admission to evaluate serum levels of 25-hydroxivitamin D [25(OH)D] and inflammatory markers. Vitamin D levels classified the individuals in sufficient (VDS ≥ 30.0 ng/mL), insufficient (VDI 20.0-29.9 ng/mL), and deficient (VDD < 20.0 ng/mL) status. Patients had lower levels of 25(OH)D, higher frequency of VDD (43.45% vs. 5.08%, OR: 16.64, 95% CI: 5.66-42.92, p < 0.001), and higher inflammatory markers than controls (p < 0.05). Patients with VDD showed increased high sensitivity C-reactive protein (hsCRP) levels than those with VDS status (p = 0.043); those with poor outcome presented with lower 25(OH)D levels than those with good outcome (p = 0.008); moreover, 25(OH)D levels were negatively correlated with mRS after three-months follow-up (r = -0.239, p = 0.005). The associations between VDD and higher hsCRP levels and between 25(OH)D levels and poor outcome at short-term in acute ischemic stroke patients suggest the important role of vitamin D in the inflammatory response and pathophysiology of this ischemic event.

Vitamin D and cardiovascular disease: From atherosclerosis to myocardial infarction and stroke

There continues to be interest in understanding the role of vitamin D in the pathogenesis, epidemiology and prevention of cardiovascular disease (CVD). In fact vitamin D deficiency has been associated to an increased risk of developing CVD given to the relationship between low vitamin D levels and obesity, diabetes mellitus, dyslipidaemia, endothelial dysfunction and hypertension. However, although vitamin D has been identified as a potentially important marker of CVD, the mechanisms through which vitamin D deficiency leads from endothelial dysfunction to myocardial infarction and stroke are not fully understood. Thus, the goal of this review is to provide an updated review of the literature on the basic science of how vitamin D may affect the cardiovascular system and in particular to analyze the role that vitamin D may have in the whole dynamic process from the initiation of endothelial dysfunction to the development of myocardial infarction and stroke.

Genetic variation in vitamin D receptor gene (Fok1:rs2228570) is associated with risk of coronary artery disease

OBJECTIVE

The Fok1 polymorphism (rs2228570) in vitamin D receptor gene appears to be the only polymorphism influencing size of translated protein. Investigations into its association with coronary artery disease (CAD) are sparse.

METHODS

Male patients (n = 98) with verified CAD were recruited alongside age- and sex-matched controls (n = 55). Genotyping was performed by PCR-RFLP and plasma 25-Hydroxyvitamin D levels were assessed by HPLC-UV.

RESULTS

The C-variant (mutant) was predominantly expressed in patients compared to controls (68.9% versus 55.5%; p = 0.025). The observed genotypes were not associated with 25-Hydroxyvitamin D levels.

CONCLUSION

This study presents Fok1 polymorphism as a potential genetic marker for CAD.

Potential Predictors of Plasma Fibroblast Growth Factor 23 Concentrations: Cross-Sectional Analysis in the EPIC-Germany Study

BACKGROUND

Increased fibroblast growth factor 23 (FGF23), a bone-derived hormone involved in the regulation of phosphate and vitamin D metabolism, has been related to the development of cardiovascular disease (CVD) in chronic kidney disease patients and in the general population. However, what determines higher FGF23 levels is still unclear. Also, little is known about the influence of diet on FGF23. The aim of this study was therefore to identify demographic, clinical and dietary correlates of high FGF23 concentrations in the general population.

METHODS

We performed a cross-sectional analysis within a randomly selected subcohort of the European Prospective Investigation into Cancer and Nutrition (EPIC)-Germany comprising 2134 middle-aged men and women. The Human FGF23 (C-Terminal) ELISA kit was used to measure FGF23 in citrate plasma. Dietary data were obtained at baseline via validated food frequency questionnaires including up to 148 food items.

RESULTS

Multivariable adjusted logistic regression showed that men had a 66% lower and smokers a 64% higher probability of having higher FGF23 (≥ 90 RU/mL) levels compared, respectively, with women and nonsmokers. Each doubling in parathyroid hormone, creatinine, and C-reactive protein was related to higher FGF23. Among the dietary factors, each doubling in calcium and total energy intake was related, respectively, to a 1.75 and to a 4.41 fold increased probability of having higher FGF23. Finally, each doubling in the intake of iron was related to an 82% lower probability of having higher FGF23 levels. Results did not substantially change after exclusion of participants with lower kidney function.

CONCLUSIONS

In middle-aged men and women traditional and non-traditional CVD risk factors were related to higher FGF23 concentrations. These findings may contribute to the understanding of the potential mechanisms linking increased FGF23 to increased CVD risk.

Vitamin D for the prevention of cardiovascular disease: Are we ready for that?

A general concept of clinical benefit of vitamin D supplementation has emerged from the evidence in prevention of osteoporosis. From the cardiovascular point of view, clinical benefit of such supplementation remains less clear. Studies in vitro and in animal models demonstrated the expression of vitamin D receptors in endothelial cells, vascular smooth muscle and cardiomyocytes. Vitamin D has been directly implicated in endothelium-mediated vasodilation, anti-coagulant activity and inhibition of the inflammatory response. Indirectly, it may favor the reduction of blood pressure, myocardial hypertrophy and ventricular arrhythmias. In contrast to these mechanistic findings, cross-sectional, longitudinal and small clinical trials have not been consistent in demonstrating association between cardiovascular events and vitamin D. Besides, methodological issues in the tests for serum levels of vitamin D may also contribute to this puzzle. Hence, in the current state of knowledge, it may be too early to consider or to rule out vitamin D as a tool to either estimate or mitigate residual cardiovascular risk. In this review, we discuss recent advances and potential limitations in mechanistic and clinical evidences that are outlining the framework of interaction between vitamin D and cardiovascular risk.

No evidence that genetically reduced 25-hydroxyvitamin D is associated with increased risk of ischaemic heart disease or myocardial infarction: a Mendelian randomization study

BACKGROUND

Low plasma 25-hydroxyvitamin D [p-25(OH)D] is associated with increased risk of ischaemic heart disease and with the subgroup myocardial infarction. However, whether this association is causal or due to confounding or reverse causation is presently unknown. We tested the hypothesis that genetically reduced plasma 25(OH)D is associated with increased risk of ischaemic heart disease and myocardial infarction.

METHODS

We used a Mendelian randomization design in the Copenhagen City Heart Study, the Copenhagen General Population Study, and the Copenhagen Ischaemic Heart Disease Study. Two 25(OH)D reducing genetic variants in the DCHR7 gene (rs7944926 and rs11234027) and two in the CYP2R1 gene (rs10741657 and rs12794714) were genotyped in 92 416 participants of Danish descent, of whom 14 455 developed ischaemic heart disease (ICD-8:410-414; ICD-10:I20-I25) and 7061 myocardial infarction (ICD-8:410: ICD-10:I21-I22) from 1977 through 2011. P-25(OH)D was measured in 36,089 participants. APOE genotype was included as a positive control for risk of ischaemic heart disease.

RESULTS

The multivariable adjusted hazard ratios for lowest vs highest quartile of 25(OH)D were 1.82 [95% confidence interval (CI): 1.42-2.32] for ischaemic heart disease. Each allele increase in a combined allele score was associated with a 1.9-nmol/l decrease in p-25(OH)D (P = 7 × 10(-55); R(2) = 0.9%). The genetic variants were, however, not associated with increased risk of ischaemic heart disease. In instrumental variable analysis, the odds ratio for ischaemic heart disease for a genetically 25-nmol/l decrease in p-25(OH)D was 0.98 (95% CI: 0.76-1.26), with a corresponding observational hazard ratio by Cox regression of 1.07 (1.01-1.13). Similarly, with myocardial infarction as the outcome, observational analyses suggested an increased risk with lower 25(OH)D, whereas genetic analyses suggested no causal effect. For APOE genotype, the odds ratio for ischaemic heart disease for a 1-mmol/l genetic increase in plasma total cholesterol concentrations was 1.23 (1.08-1.41), with a corresponding observational hazard ratio of 1.08 (1.04-1.14).

CONCLUSION

We found no evidence to suggest that genetically reduced p-25(OH)D is associated with increased risk of ischaemic heart disease or myocardial infarction.

Plasma fibroblast growth factor 23 and risk of cardiovascular disease: results from the EPIC-Germany case-cohort study

Increased fibroblast growth factor 23 (FGF23) concentrations have emerged as a novel risk factor for heart failure and stroke but not for myocardial infarction (MI). Yet, most studies on MI were conducted in coronary artery disease (CAD) patients and the elderly. Evidence is unclear in subjects without CAD and for stroke subtypes. We investigated the relationships between FGF23 and overall major cardiovascular endpoints, incident MI, ischemic (IS) and haemorrhagic stroke (HS) in middle-aged adults without pre-existing cardiovascular disease. We used a case-cohort study nested within the European Prospective Investigation into Cancer and Nutrition-Germany, including a randomly drawn subcohort (n = 1,978), incident MI (n = 463) and stroke cases (n = 359 IS; n = 88 HS) identified during a mean follow-up of 8.2 years. Compared with participants with FGF23 levels in the lowest quartile, those in the highest quartile had a 36% increased risk for cardiovascular events [hazard ratio: 1.36, 95% confidence interval (CI): 1.02-1.82] after adjustment for established cardiovascular risk factors, patahyroid hormone and 25-hydroxyvitamin D3 levels, dietary calcium and phosphorus intake, and kidney function. However, sub-analyses revealed significant relationships with risk of MI and HS, but not IS. Compared with the lowest quartile, individuals in the top two FGF23 quartiles had a 1.62 (95% CI 1.07-2.45) fold increased risk for MI and a 2.61 (95% CI 1.23-5.52) fold increase for HS. Increased FGF23 emerged as a risk factor for both MI and HS. Further studies are warranted to confirm these results and to identify underlying mechanisms.

Triangular relationship between single nucleotide polymorphisms in the CYP2R1 gene (rs10741657 and rs12794714), 25-hydroxyvitamin d levels, and coronary artery disease incidence

OBJECTIVE

To investigate the relationship between the rs10741657 and rs12794714 polymorphisms in the CYP2R1 gene, 25(OH)D levels, and coronary artery disease (CAD) incidence.

METHODS

In total, 134 male patients with verified CAD were recruited, alongside 109 age- and sex-matched controls. Genotyping was performed by polymerase chain reaction-restriction fragment length polymorphism, using the corresponding restriction enzyme for each polymorphism, whereas 25(OH)D levels were analyzed by HPLC-UV.

RESULTS

25(OH)D levels were significantly lower in patients. The genotypic and allelic distributions of the rs10741657 polymorphism were significantly different between patients and controls, whereas insignificant results were obtained for the rs12794714 polymorphism. Furthermore, rs10741657, but not rs12794714, predicted 25(OH)D levels.

CONCLUSION

The rs10741657 polymorphism is a novel genetic marker for CAD.

Acute Phase Response: Implication in ST-segment Elevation Myocardial Infarction

We aimed to investigate the relation between serum inflammatory markers, 25OHvit-D3 and oxidative stress markers, namely paraoxonase1-arylesterase (PON1-ARE), total antioxidant status (TAS) and total oxidant status (TOS) in 30 male patients with ST-elevation myocardial infarction(STEMI) . There was negative correlation between tumor necrosis factor alpha and ARE; positive correlations between serum amyloid A(SAA) and oxidative stress index, SAA and TOS, 25OHvit-D3 and ARE. There was no statistically significant correlation between inflammation makers, oxidative stress markers and Gensini score. The main finding of our study was the tendency of inflammation markers, and oxidative stress markers, to change in relatively clear opposite directions in STEMI.

Serum 25-hydroxyvitamin d deficiency in ischemic stroke and subtypes in Indian patients

BACKGROUND AND PURPOSE

Vitamin D deficiency is common across all age groups and may contribute to cardiovascular diseases. Serum 25-hydroxyvitamin D deficiency causing ischemic stroke has been documented in recent reports.

AIM

To investigate the association of serum 25-hydroxyvitamin D deficiency with ischemic stroke and subtypes.

METHODS

We recruited 250 consecutive ischemic stroke patients and 250 age and sex matched controls attending the Department of Neurology, at Yashoda hospital, Hyderabad, India, from January 2011 to December 2012. All ischemic stroke patients underwent stroke subtyping. We measured 25-hydroxyvitamin D by chemiluminescence test, serum calcium, phosphorus, alkaline phosphatase, and C-reactive protein (CRP) in cases and controls.

RESULTS

Out of 250 stroke patients, 190 (76%) were men and mean age was 58.4±11.1 years (age range-26-89 years). 25-hydroxyvitamin D deficiency was observed in 122 (48.8%) stroke patients and 79 (31.6%) controls (P=0.001). Among stroke patients, serum 25-hydroxyvitamin D deficiency was found in 54.9% (50/91) of patients with large artery atherosclerosis, 54% (20/37) in cardioembolic stroke, 44.4% (20/45) in small artery diseases, 42.8% (15/35) in stroke of other determined etiology and 40.4% (17/42) in stroke of un-determined etiology. Multiple logistic regression analysis showed an independent association of 25-hydroxyvitamin D deficiency with ischemic stroke (odds ratio: 1.6; 95% CI 1.2-2.8). The association was strongest with large artery atherosclerosis (odds ratio: 2.4; 95% CI 1.6-3.5) and cardioembolic stroke (odds ratio: 2.0; 95% CI 1.0-3.2).

CONCLUSIONS

We found that 25-hydroxyvitamin D deficiency had an independent association with ischemic stroke. The association was established in large artery arthrosclerosis and cardioembolic stroke.

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.