Vitamin D deficiency and its correlations with increased cardiovascular incidences

Effect of vitamin D supplementation versus placebo on essential hypertension in patients with vitamin D deficiency: a double-blind randomized clinical trial

Findings from randomized trials addressing the effect of vitamin D supplementation and blood pressure are inconsistent and have been the subject of recent debate. This study aimed to assess the effect of vitamin D supplementation on primary hypertension. This double-blind randomized clinical trial was conducted on patients aged 26-84 years with essential hypertension from March 2017 to April 2019. Patients with vitamin D insufficiency (serum vitamin D levels 20-30 ng/ml) or vitamin D deficiency (serum vitamin D levels <20 ng/ml) were enrolled in the study. Patients were randomly assigned to receive vitamin D supplementation or placebo. Systolic and diastolic blood pressure was measured before the intervention and one and two months thereafter. Of 208 patients enrolled, 171 patients remained for analysis. The effect of vitamin D supplementation on systolic blood pressure was statistically significant in the first and second months after the intervention (P=0.004 and P=0.024, respectively). The effect of vitamin D supplementation on diastolic blood pressure was statistically significant in the first month after the intervention (P=0.046), but not in the second month (P=0.885). No evidence of drug side effects was reported in the two groups. The results of this trial are suggestive of the potential benefits of vitamin D supplementation on blood pressure end points. Therefore, the use of vitamin D may be recommended as an adjuvant drug in the treatment of essential hypertension in patients with vitamin D deficiency because it is safe and well-tolerated by the patients and can significantly reduce the systolic and diastolic blood pressure. Trial registration: Iranian Registry of Clinical Trials registration number: IRCT201703129014N151.

Influence of vitamin D status on the effect of statins on bone mineral density and bone turnover markers in postmenopausal women

OBJECTIVE

This study sought to assess whether the association between statin use and bone mineral density (BMD) and bone turnover markers is modulated by serum 25-hydroxyvitamin D (25OHD) levels in postmenopausal women. Design, Participants, and Settings: Approximately 1422 postmenopausal women were recruited from the Camargo Cohort after excluding those with any known medical disorder or drug that might affect bone metabolism. Participants were categorized into four groups: 25OHD levels of 20 ng/mL or less and not taking statins (group 1; n = 492); 25OHD levels greater than 20 ng/mL and on statins (group 2; n = 143); 25OHD levels of 20 ng/mL or less and using statins (group 3; n = 112); and 2OHD levels greater than 20 ng/mL and non-statin use (group 4; n = 675). Multivariate analyses were performed to compare BMD and bone turnover markers between groups.

RESULTS

Women in group 2 had an adjusted femoral neck and total hip BMD higher than women in group 1 (P < .0001 and P = .003, respectively). A trend toward a significant difference was observed regarding lumbar BMD (P = .08). Serum aminoterminal propeptide of type 1 collagen and C-terminal telopeptide of type 1 collagen levels were lower in group 2 than in group 1, in crude and adjusted models, although only serum C-terminal telopeptide of type 1 collagen difference was significant (P = .009).

CONCLUSIONS

Women on statins and serum 25OHD levels above 20 ng/mL have greater BMD and less bone resorption than those without either of the factors. Differences, however, are not significant in women with only one of them. Vitamin D and statins seem to interact positively in their effects on bone metabolism.

The implication of vitamin D and autoimmunity: a comprehensive review

Historically, vitamin D has been associated with the regulation of bone metabolism. However, increasing evidence demonstrates a strong association between vitamin D signaling and many biological processes that regulate immune responses. The discovery of the vitamin D receptor in multiple immune cell lineages, such as monocytes, dendritic cells, and activated T cells credits vitamin D with a novel role in modulating immunological functions and its subsequent role in the development or prevention of autoimmune diseases. In this review we, discuss five major areas in vitamin D biology of high immunological significance: (1) the metabolism of vitamin D; (2) the significance of vitamin D receptor polymorphisms in autoimmune diseases, such as multiple sclerosis, type 1 diabetes mellitus, and systemic lupus erythematosus; (3) vitamin D receptor transcriptional regulation of immune cell lineages, including Th1, Th17, Th2, regulatory T, and natural killer T cells; (4) the prevalence of vitamin D insufficiency/deficiency in patients with multiple sclerosis, type 1 diabetes mellitus, and systemic lupus erythematosus; and finally, (5) the therapeutic effects of vitamin D supplementation on disease severity and progression.

25 hydroxyvitamin D levels in patients undergoing coronary artery catheterization

INTRODUCTION

A growing body of evidence suggests that vitamin D deficiency is associated with increased cardiovascular morbidity and mortality. The present study assessed the association between low serum 25-hydroxyvitamin D (25(OH)D) and coronary artery disease status defined by coronary catheterization findings.

METHODS

An observational study of 101 consecutive patients admitted to Assaf Harofeh Medical Center during 2009, and scheduled to undergo coronary catheterization was undertaken. Blood was collected for parathyroid hormone, 25(OH)D and high sensitivity C reactive protein (hsCRP). 25(OH)D deficiency was defined as <20 ng/ml. Patients were divided into two groups: patients with normal or non-significant coronary artery disease and patients with a significant coronary artery disease as found during cardiac catheterization. Logistic regression model was used to compare pathological coronary catheterization findings, including 25(OH)D levels dichotomized to low (serum 25(OH)D levels<20 ng/ml) vs. high (serum 25(OH)D levels ≥ 20 ng/ml) and other confounders.

RESULTS

Patients with pathological coronary catheterization had 25(OH)D deficiency (75% vs 55.1%, p=0.036). Pathological coronary catheterization was more prevalent among patients with 25(OH)D deficiency (Odds ratio (OR) 2.44, 95% confidence interval (CI) 1.05-5.68, p=0.038). This difference was more pronounced after controlling for sex, age, BMI, ethnicity and present smoking (OR 2.92, 95% CI 1.01-8.46, p=0.016).

CONCLUSIONS

25(OH)D deficiency is significantly associated with pathological cardiac catheterization findings. This association is strengthened further by controlling for other cardiovascular disease risk factors.

Vitamin D deficiency exacerbates experimental stroke injury and dysregulates ischemia-induced inflammation in adult rats

Vitamin D deficiency (VDD) is widespread and considered a risk factor for cardiovascular disease and stroke. Low vitamin D levels are predictive for stroke and more fatal strokes in humans, whereas vitamin D supplements are associated with decreased risk of all-cause mortality. Because VDD occurs with other comorbid conditions that are also independent risk factors for stroke, this study examined the specific effect of VDD on stroke severity in rats. Adult female rats were fed control or VDD diet for 8 wk and were subject to middle cerebral artery occlusion thereafter. The VDD diet reduced circulating vitamin D levels to one fifth (22%) of that observed in rats fed control chow. Cortical and striatal infarct volumes in animals fed VDD diet were significantly larger, and sensorimotor behavioral testing indicated that VDD animals had more severe poststroke behavioral impairment than controls. VDD animals were also found to have significantly lower levels of the neuroprotective hormone IGF-I in plasma and the ischemic hemisphere. Cytokine analysis indicated that VDD significantly reduced IL-1α, IL-1β, IL-2, IL-4, IFN-γ, and IL-10 expression in ischemic brain tissue. However, ischemia-induced IL-6 up-regulation was significantly higher in VDD animals. In a separate experiment, the therapeutic potential of acute vitamin D treatments was evaluated, where animals received vitamin D injections 4 h after stroke and every 24 h thereafter. Acute vitamin D treatment did not improve infarct volume or behavioral performance. Our data indicate that VDD exacerbates stroke severity, involving both a dysregulation of the inflammatory response as well as suppression of known neuroprotectants such as IGF-I.

The JUPITER lipid lowering trial and vitamin D: Is there a connection?

There is growing evidence that vitamin D deficiency significantly increases the risk of adverse cardiovascular events and that a vitamin D status representing sufficiency or optimum is protective. Unfortunately, in clinical trials that address interventions for reducing risk of adverse cardiovascular events, vitamin D status is not generally measured. Failure to do this has now assumed greater importance with the report of a study that found rosuvastatin at doses at the level used in a recent large randomized lipid lowering trial (JUPITER) had a large and significant impact on vitamin D levels as measured by the metabolite 25-hydroxyvitamin D. The statin alone appears to have increased this marker such that the participants on average went from deficient to sufficient in two months. The difference in cardiovascular risk between those deficient and sufficient in vitamin D in observational studies was similar to the risk reduction found in JUPITER. Thus it appears that this pleiotropic effect of rosuvastatin may be responsible for part of its unusual effectiveness in reducing the risk of various cardiovascular endpoints found in JUPITER and calls into question the interpretation based only on LDL cholesterol and CRP changes. In addition, vitamin D status is a cardiovascular risk factor which up until now has not been considered in adjusting study results or in multivariate analysis, and even statistical analysis using only baseline values may be inadequate.