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

Prevalence of 25-hydroxyvitamin D deficiency in the acute rehabilitation population following traumatic brain injury

OBJECTIVE

To determine the prevalence of vitamin D deficiency among individuals with traumatic brain injury (TBI) undergoing acute inpatient rehabilitation.

SETTING

Inpatient rehabilitation.

PARTICIPANTS

Participants were admitted from November 1st, 2010 through June 30th, 2015 with diagnosis of mild-severe TBI and had serum 25 OH vitamin D levels checked upon admission. 369 out of 845 met inclusion.

DESIGN

Retrospective cohort.

MAIN MEASURES

25 OH vitamin D, vitamin D treatment.

RESULTS

The majority of patients were male (67%), Caucasian (89%) with private insurance (61%) and a mean age of 43.5±21.0 years. 25 OH vitamin D levels were categorized: deficient (<20 ng/mL), insufficient (20-29.9 ng/mL), and sufficient (≥30 ng/mL). There were 95 (26%) patients that were deficient, 131 (36%) that were insufficient, and 143 (39%) that were sufficient. Race/ethnicity was found to be significant (p = 0.0145) with the largest percentage of Hispanics found in the insufficient and deficient categories, and the largest percentage of Blacks in the deficient category. Most patients with deficient or insufficient vitamin D levels were prescribed vitamin D replacement during their rehab stay (p < 0.0001).

CONCLUSION

The majority of patients undergoing acute inpatient rehabilitation were found to have insufficient or deficient vitamin D levels, therefore it should be routinely screened and treated as indicated.

Vitamin D metabolism in dogs and cats and its relation to diseases not associated with bone metabolism

Due to the presence of receptors in the cells of numerous body tissues, vitamin D is associated with several physiological functions that go beyond calcium and phosphorus homoeostasis and control of bone metabolism in the body. In humans, several studies have associated lower vitamin D concentrations with numerous diseases, such as cancer, heart disease, autoimmune diseases and infectious diseases, and also with an increase in the total mortality rate of the population. Recently, this nutrient started to gain importance in veterinary medicine, and several articles have shown a correlation between low vitamin D status and diseases unrelated to bone metabolism. The present review aims to highlight the recent publications that investigated this relationship, bringing the evidence that exists so far in dogs and cats.

Vitamin D receptor activation regulates microglia polarization and oxidative stress in spontaneously hypertensive rats and angiotensin II-exposed microglial cells: Role of renin-angiotensin system

Hypertension is one of the major predisposing factors for neurodegenerative disease characterized with activated renin-angiotensin system (RAS) in both periphery and brain. Vitamin D (VitD) is recently recognized as a pleiotropic hormone with strong neuroprotective properties. While multiple lines of evidence suggest that VitD can act on RAS, the evidence concerning the crosstalk between VitD and RAS in the brain is limited. Therefore, this study aims to evaluate whether VitD can modulate brain RAS to trigger neuroprotective actions in the brain of spontaneously hypertensive rats (SHR). Our data showed that calcitriol treatment induced VDR expression and inhibited neural death in the prefrontal cortex of SHR. Sustained calcitriol administration also inhibited microglia M1 polarization, but enhanced M2 polarization, accompanied with decreased expression of proinflammatory cytokines. We then further explored the potential mechanisms and showed that SHR exhibited overactivated classical RAS with increased expression of angiotensin II (Ang II) receptor type 1 (AT1), angiotensin converting enzyme (ACE) and Ang II production, whereas the counteracting arm of traditional RAS, ACE2/Ang(1-7)/MasR, was impaired in the SHR brain. Calcitriol nonsignificantly suppressed AT1 and ACE but markedly reduced Ang II formation. Intriguingly, calcitriol exerted pronouncedly impact on ACE2/Ang(1-7)/MasR axis with enhanced expression of ACE2, MasR and Ang(1-7) generation. Meanwhile, calcitriol ameliorated the overactivation of NADPH-oxidase (Nox), the downstream of RAS, in SHR, and also mitigated oxidative stress. In microglial (BV2) cells, we further found that calcitriol induced ACE2 and MasR with no significant impact on ACE and AT1. In accordance, calcitriol also attenuated Ang II-induced Nox activation and ROS production, and shifted the microglia polarization from M1 to M2 phenotype. However, co-treatment with A779, a specific MasR antagonist, abrogated the antioxidant and neuroimmune modulating actions of VitD. These findings strongly indicate the involvement of ACE2/Ang(1-7)/MasR pathway in the neuroprotective mechanisms of VitD in the hypertensive brain.

Vitamin D Status and Risk of Stroke

Background and Purpose—

Recent findings suggest that vitamin D, a neuroprotective prohormone, is involved in the pathogenesis of cardiovascular disease. However, previous studies investigating the association between vitamin D and stroke have shown inconsistent findings. In view of these discrepancies, we determined the association of vitamin D status with stroke using data from a population-based study.

Methods—

Within the RS (Rotterdam Study), an ongoing prospective population-based study, we measured serum 25-hydroxyvitamin D concentrations between 1997 and 2008 in 9680 participants (56.8% women) aged ≥45 years. We assessed a history of stroke at baseline and subsequently followed for incident stroke until January 1, 2016. Regression models were used to investigate the association of serum 25-hydroxyvitamin D with prevalent and incident stroke separately, adjusted for age, sex, study cohort, season of blood sampling, and other cardiovascular risk factors.

Results—

Of 9680 participants, 339 had a history of stroke at baseline. Serum 25-hydroxyvitamin D concentration was associated with prevalent stroke, adjusted odds ratio per SD decrease, 1.31; 95% CI, 1.14–1.51. After excluding participants with prevalent stroke, we followed 9338 participants for a total of 98 529 person-years. During follow-up, 735 participants developed a stroke. Lower serum 25-hydroxyvitamin D concentration was not associated with a higher stroke risk, adjusted hazard ratio per SD decrease, 1.06; 95% CI, 0.97–1.16. However, severe vitamin D deficiency did show a significant association: hazard ratio, 1.25; 95% CI, 1.05–1.50.

Conclusions—

In this population-based cohort, we found an association between vitamin D and prevalent stroke. Only severe vitamin D deficiency was associated with incident stroke. This suggests that lower vitamin D levels do not lead to a higher stroke risk but are instead a consequence of stroke.

Inhibition of platelet activation using vitamins

Some vitamins have beneficial effects on cardiovascular diseases, normalizing platelet function and preventing their excess activation. Anti-platelet vitamins can act directly through inhibitory biochemical pathways in platelets or indirectly by preventing damage to the endothelium or low-density lipoprotein from oxidation. As a rule, each vitamin alone is a weak inhibitor of platelet aggregation. However, in combination, they may act synergistically or enhance the effects of endogenous anti-platelet compounds, such as prostacyclin or nitric oxide, and appear to have a sufficient anti-thrombotic effect. This review will focus on vitamins, which inhibit platelet activation and the mechanisms of their action. The relationship between the vitamins that inhibit platelet aggregation and vascular diseases is examined.

Role of Vitamin D Status in Diabetic Patients with Renal Disease

Diabetes mellitus (DM) poses a major public health problem worldwide, with ever-increasing incidence and prevalence in recent years. The Institute for Alternative Futures (IAF) expects that the total number of people with type 1 and type 2 DM in the United States will increase by 54%, from 19,629,000 to 54,913,000 people, between 2015 and 2030. Diabetic Nephropathy (DN) affects about one-third of patients with DM and currently ranks as the first cause of end-stage kidney disease in the Western world. The complexity of interactions of Vitamin D is directly related with progressive long-term changes implicated in the worsening of renal function. These changes result in a dysregulation of the vitamin D-dependent pathways. Various studies demonstrated a pivotal role of Vitamin D supplementation in regression of albuminuria and glomerulosclerosis, contrasting the increase of glomerular basement membrane thickening and podocyte effacement, with better renal and cardiovascular outcomes. The homeostasis and regulation of the nephron’s function are absolutely dependent from the cross-talk between endothelium and podocytes. Even if growing evidence proves that vitamin D may have antiproteinuric, anti-inflammatory and renoprotective effects in patients with DN, it is still worth investigating these aspects with both more in vitro studies and randomized controlled trials in larger patient series and with adequate follow-up to confirm the effects of long-term vitamin D analogue supplementation in DN and to evaluate the effectiveness of this therapy and the appropriate dosage.

Pragmatic Analysis of Dyslipidemia Involvement in Coronary Artery Disease: A Narrative Review

Background

Dyslipidemia is the main factor involved in the occurrence and progression of coronary artery disease.

Objective

The research strategy is aimed at analyzing new data on the pathophysiology of dyslipidemia involvement in coronary artery disease, the modalities of atherogenic risk estimation and therapeutic advances.

Methods

Scientific articles published in PubMed from January 2017 to February 2018 were searched using the terms “dyslipidemia” and “ischemic heart disease”.

Results

PCSK9 contributes to the increase in serum levels of low-density lipoprotein-cholesterol and lipoprotein (a). The inflammation is involved in the progression of hyperlipidemia and atherosclerosis. Hypercholesterolemia changes the global cardiac gene expression profile and is thus involved in the increase of oxidative stress, mitochondrial dysfunction, and apoptosis initiated by inflammation. Coronary artery calcifications may estimate the risk of coronary events. The cardio-ankle vascular index evaluates the arterial stiffness and correlates with subclinical coronary atherosclerosis. The carotid plaque score is superior to carotid intima-media thickness for risk stratification in patients with familial hypercholesterolemia and both can independently predict coronary artery disease. The lipoprotein (a) and familial hypercholesterolemia have a synergistic role in predicting the risk of early onset and severity of coronary atherosclerosis. A decrease in atherosclerotic coronary plaque progression can be achieved in patients with plasma LDL-cholesterol levels below 70 mg/dL. A highly durable RNA interference therapeutic inhibitor of PCSK9 synthesis could be a future solution.

Conclusion

The prophylaxis and treatment of coronary artery disease in a dyslipidemic patient should be based on a careful assessment of cardio-vascular risk factors and individual metabolic particularities, so it may be personalized.

Acute Effects of Single Doses of Bonito Fish Peptides and Vitamin D on Whole Blood Gene Expression Levels: A Randomized Controlled Trial

Fish contains high quality proteins and essential nutrients including 25-hydroxyvitamin D (25(OH)D). Fish peptide consumption can lower cardiovascular disease (CVD) risk factors, and studies have shown an association between 25(OH)D deficiency, CVD and CVD risk factors, such as diabetes. This study investigated acute effects of a single dose of cholecalciferol (VitD₃), bonito fish peptide hydrolysate (BPH), or a combination of both on CVD risk factors and whole blood gene expression levels. A randomized, crossover, placebo controlled trial was conducted in 22 adults. They ingested, in random order and at 7-day intervals, 1000 IU of VitD₃, 3 g of BPH, a combination of both, or a placebo. A 180 min oral glucose tolerance test was performed. Differences in whole-genome expression levels after versus before each supplementation were computed for 18 subjects. We observed that 16, 1 and 5 transcripts were differentially expressed post- vs. pre-ingestion for VitD₃, BPH or VitD₃ + BPH treatments, respectively. VitD₃-containing treatments affected the expression of the solute carrier family 25 member 20 (SLC25A20) gene involved in fatty acid oxidation, various transcription factors and genes related to glucose metabolism. These results suggest that VitD₃ rapidly modulates genes related to CVD risk factors in blood while BPH seems to moderately modulate gene expression levels.

What is the Current Role for Vitamin D and the Risk of Stroke?

INTRODUCTION

Increasing evidence supports the relationship between vitamin D and stroke. Vitamin D has now been proposed as a prognostic biomarker also for functional outcome in stroke patients.

METHODS

A revision of the data suggests that low vitamin D is associated more with ischemic than with haemorrhagic stroke, even if the role of optimal vitamin D levels for vascular wall is still unclear. Vitamin D deficiency induces with different mechanisms an alteration of vascular wall.

RESULTS

However, to date, the research supporting the effectiveness of vitamin D supplementation in stroke and in post-stroke recovery is still inadequate and conclusive evidences have not been published.

CONCLUSION

In this review, we provide a better understanding of the role of vitamin D in stroke.

Obesity and hypovitaminosis D: causality or casualty?

Epidemiological studies reported that vitamin D deficiency represents an increasingly widespread phenomenon in various populations. Vitamin D deficiency is considered a clinical syndrome determined by low circulating levels of 25-hydroxyvitamin D (25(OH)D), which is the biologically-inactive intermediate and represents the predominant circulating form. Different mechanisms have been hypothesized to explain the association between hypovitaminosis D and obesity, including lower dietary intake of vitamin D, lesser skin exposure to sunlight, due to less outdoor physical activity, decreased intestinal absorption, impaired hydroxylation in adipose tissue and 25(OH)D accumulation in fat. However, several studies speculated that vitamin D deficiency itself could cause obesity or prevent weight loss. The fat-solubility of vitamin D leads to the hypothesis that a sequestration process occurs in body fat depots, resulting in a lower bioavailability in the obese state. After investigating the clinical aspects of vitamin D deficiency and the proposed mechanisms for low 25(OH)D in obesity, in this manuscript we discuss the possible role of vitamin D replacement treatment, with different formulations, to restore normal levels in individuals affected by obesity, and evaluate potential positive effects on obesity itself and its metabolic consequences. Food-based prevention strategies for enhancement of vitamin D status and, therefore, lowering skeletal and extra-skeletal diseases risk have been widely proposed in the past decades; however pharmacological supplementation, namely cholecalciferol and calcifediol, is required in the treatment of vitamin D insufficiency and its comorbidities. In individuals affected by obesity, high doses of vitamin D are required to normalize serum vitamin D levels, but the different liposolubility of different supplements should be taken into account. Although the results are inconsistent, some studies reported that vitamin D supplementation may have some beneficial effects in people with obesity.

Common mechanisms and holistic care in atherosclerosis and osteoporosis

Cardiovascular (CV) disease and osteoporosis (OP) have become increasing challenges in the aging population and even more in patients with inflammatory rheumatic diseases, such as rheumatoid arthritis, spondyloarthropathies, and systemic lupus erythematosus. In this review, we discuss how the epidemiology and pathogenesis of CV events and OP are overlapping. Smoking, diabetes mellitus, physical inactivity as conventional risk factors as well as systemic inflammation are among the modifiable risk factors for both CV events and bone loss. In rheumatic patients, systemic “high-grade” inflammation may be the primary driver of accelerated atherogenesis and bone resorption. In the general population, in which some individuals might have low-grade systemic inflammation, a holistic approach to drug treatment and lifestyle modifications may have beneficial effects on the bone as well as the vasculature. In rheumatic patients with accelerated inflammatory atherosclerosis and bone loss, the rapid and effective suppression of inflammation in a treat-to-target regime, aiming at clinical remission, is necessary to effectively control comorbidities.

Vitamin D and Metabolic Diseases: Growing Roles of Vitamin D

Vitamin D, a free sunshine vitamin available for mankind from nature, is capable to avert many health-related critical circumstances. Vitamin D is no more regarded as a nutrient involved in bone metabolism alone. The presence of vitamin D receptor in a number of tissues implies that vitamin D has various physiological roles apart from calcium and phosphorus metabolism. Low serum vitamin D has been found to be associated with various types of metabolic illness such as obesity, diabetes mellitus, insulin resistance, cardiovascular diseases including hypertension. Various studies reported that vitamin D insufficiency or deficiency in linked with metabolic syndrome risk. This review focuses on various metabolic diseases and its relationship with serum vitamin D status.

Analysis of Plasma Albumin, Vitamin D, and Apolipoproteins A and B as Predictive Coronary Risk Biomarkers in the REGICOR Study

INTRODUCTION AND OBJECTIVES

New biomarkers could improve the predictive capacity of classic risk functions. The aims of this study were to determine the association between circulating levels of apolipoprotein A1 (apoA1), apolipoprotein B (apoB), albumin, and 25-OH-vitamin D and coronary events and to analyze whether these biomarkers improve the predictive capacity of the Framingham-REGICOR risk function.

METHODS

A case-cohort study was designed. From an initial cohort of 5404 individuals aged 35 to 74 years with a 5-year follow-up, all the participants who had a coronary event (n = 117) and a random group of the cohort (subcohort; n = 667) were selected. Finally, 105 cases and 651 individuals representative of the cohort with an available biological sample were included. The events of interest were angina, fatal and nonfatal myocardial infarction and coronary deaths.

RESULTS

Case participants were older, had a higher proportion of men and cardiovascular risk factors, and showed higher levels of apoB and lower levels of apoA1, apoA1/apoB ratio, 25-OH-vitamin D and albumin than the subcohort. In multivariate analyses, plasma albumin concentration was the only biomarker independently associated with coronary events (HR, 0.73; P = .002). The inclusion of albumin in the risk function properly reclassified a significant proportion of individuals, especially in the intermediate risk group (net reclassification improvement, 32.3; P = .048).

CONCLUSIONS

Plasma albumin levels are inversely associated with coronary risk and improve the predictive capacity of classic risk functions.

Associations of 25-Hydroxyvitamin D With the Blood Pressure Response to Maximal Exercise Among Healthy Adults

Insufficient 25-hydroxyvitamin D [25(OH)D] levels are associated with high resting blood pressure (BP). However, the relationship between 25(OH)D and the peak systolic BP (SBP) response to exercise, a predictor of future hypertension, has yet to be investigated. We sought to examine the relationship among serum 25(OH)D and the peak SBP response to a graded exercise stress test (GEST) among a large sample (n = 417) of healthy men (49%) and women (51%) over a broad age range (20-76 years; mean age: 44.1 ± 0.8 years). We hypothesized that individuals with clinically insufficient 25(OH)D would have a greater peak SBP response to a GEST compared to individuals with sufficient 25(OH)D levels. Fasting serum 25(OH)D, anthropometrics, resting BP, and peak exercise SBP were obtained at the baseline visit of a larger clinical trial (STOMP; NCT01140308). Mean 25(OH)D levels were 36.1 ± 0.7 ng/ml, with ∼35% of individuals classified as insufficient (<30 ng/ml). Average resting BP was 119 ± 13 mmHg/75 ± 10 mmHg, with 52.3% considered to have normal BP, while 25.2% had elevated BP and 22.5% had established hypertension. The peak SBP response to a GEST was similar between individuals with sufficient (48 ± 19 mmHg) versus insufficient (48 ± 18 mmHg) 25(OH)D (p = 1.000). One unexpected finding emerged such that individuals with sufficient 25(OH)D had higher resting SBP (120 ± 14 mmHg vs. 117 ± 13 mmHg; p = .020) than individuals with insufficient 25(OH)D. In contrast to our hypothesis, 25(OH)D levels were not associated with the peak SBP response to a GEST. Baseline 25(OH)D levels were positively correlated with resting SBP; however, the magnitude of this effect is likely not clinically meaningful.

Serial assessment of endothelial function 1, 6, and 12 months after ST-elevation myocardial infarction

Knowledge about the changes in endothelial function after ST-elevation myocardial infarction (STEMI) is of substantial interest, but serial data are scarce. The aim of the present study was to noninvasively evaluate whether endothelial function, as assessed shortly after primary percutaneous coronary intervention (PPCI) for STEMI, may improve until 12-month follow-up. This prospective observational cohort study was performed in patients in the RESPONSE randomized trial who participated in a substudy and underwent noninvasive assessment of endothelial function at 1 (baseline), 6, and 12-month follow-up after treatment of a STEMI by PPCI. The reactive hyperemia peripheral artery tonometry (RH-PAT) method was used to assess endothelial function (higher RH-PAT index signifies better function). Of the 70 study participants, who were 57.4 ± 9.7 years of age, 55 (78.6%) were male and 9 (13%) had diabetes. The endothelial function deteriorated significantly during follow-up: the RH-PAT index at baseline, 6, and 12-month follow-up was 1.90 ± 0.58, 1.81 ± 0.57, and 1.69 ± 0.49, respectively (p = 0.04). Although patients were carefully treated in outpatient clinics and adequate pharmacological therapy was prescribed, we noted an increase in total cholesterol (p = 0.001), LDL cholesterol (p = 0.002), HbA1C (p = 0.054), and diastolic blood pressure (p = 0.047) However, multivariate analysis revealed that this increase in cardiovascular risk factors could not explain the observed deterioration in endothelial function. In patients with STEMI, we observed a significant deterioration in endothelial function during 12 months after PPCI that could not be explained by changes in the traditional cardiovascular risk profile.

Fetuin B links vitamin D deficiency and pediatric obesity: Direct negative regulation by vitamin D

Vitamin D (VD) deficiency (VDD) correlates to obesity, with VD a recognized mediator of metabolic diseases. From a previous proteomic study identifying adiponectin as a link between VDD and pediatric obesity, herein we analysed another protein (SSP2301) increased with VDD. A focused 2D-electrophoretic analysis identified 4 corresponding plasma proteins, with one predicted to be fetuin B (FETUB). FETUB was studied due to its emerging role in metabolic diseases and cytogenetic location (3q27.3) with adiponectin. Results were confirmed in obese children, where plasma FETUB was higher with VDD. A direct effect by 1α,25-(OH)2D3 on hepatocellular FETUB synthesis was observed, with a time and dose dependent reduction. Further, we demonstrated the VD-receptor (VDR) is key, with FETUB "released" with VDR silencing. Finally, VD supplementation (6weeks) to juvenile mice fed a standard diet, reduced plasma FETUB. Only at 22weeks did liver FETUB correspond to plasma FETUB, highlighting the contribution of other VD-responsive tissues. Overall, FETUB is a key protein linking VDD to pediatric obesity. With an emerging role in metabolic diseases, we demonstrate that VD/VDR directly regulate FETUB.

Vitamin D deficiency and risk of cardiovascular diseases: a narrative review

Vitamin D, a fat-soluble prohormone, has wide-ranging roles in the regulation of many physiological processes through their interactions with the vitamin D receptors (VDR). It plays a major role in bones and calcium metabolism. Vitamin D deficiency is not uncommon and it has been associated with many health-related issues, including skeletal and non-skeletal complications. The association of low vitamin D and cardiovascular diseases and risk factors has been explored in both animal and human studies. However, studies and trials on the effect of vitamin D supplementation on cardiovascular risk factors and hypertension are conflicting with inconsistent results. Therefore, large, well-powered randomized controlled trials are warranted. If successful, supplementation with easy and low-cost vitamin D can impact our health positively. Here, we summarized the evidence for the association of vitamin D, cardiovascular diseases and risk factors, including coronary artery diseases, stroke, and hypertension, and mortality, with special consideration to resistant hypertension.

Combined treatment with benzo[a]pyrene and 1α,25-dihydroxyvitamin D3 induces expression of plasminogen activator inhibitor 1 in monocyte/macrophage-derived cells

Benzo[a]pyrene (BaP) is an environmental pollutant found in cigarette smoke and is implicated as a causative agent of tobacco-related diseases, such as arteriosclerosis. In contrast, vitamin D signaling, which is principally mediated by conversion of vitamin D to the active form, 1α,25-dihydroxyvitamin D₃ [1,25(OH)₂D₃], decreases cardiovascular disease risk. However, combined treatment with BaP and 1,25(OH)₂D₃ enhances BaP toxicity, including BaP-DNA adduct formation. We further investigated the cross-talk between BaP and 1,25(OH)₂D₃ signaling pathways, and found that combined treatment with these compounds induces mRNA and protein expression of plasminogen activator inhibitor 1 (PAI-1) in monocyte/macrophage-derived THP-1 and U937 cells. Protein synthesis inhibitor treatment did not inhibit induction of the PAI-1 gene (SERPINE1) in these cells. BaP plus 1,25(OH)₂D₃ induced differentiation markers, inhibited cellular proliferation, and induced apoptosis and oxidative stress in these cells. Reactive oxygen species scavenger treatment suppressed apoptosis but not SERPINE1 induction in cells treated with BaP plus 1,25(OH)₂D₃. Thus, combined treatment with BaP and 1,25(OH)₂D₃ induced SERPINE1 mRNA expression in these cells through a mechanism that does not require de novo protein synthesis or reactive oxygen species production. These findings suggest that induction of the proinflammatory factor PAI-1 plays a role in BaP toxicity. Interestingly, PAI-1 knockdown decreased expression of the cell surface antigen CD14, a monocytic differentiation marker, in THP-1 cells treated with BaP plus 1,25(OH)₂D₃. PAI-1 induction may also be related to a function of monocytes/macrophages in response to xenobiotic and vitamin D signaling.

The combined effect of vitamin D and parathyroid hormone concentrations on glucose homeostasis in older patients with prediabetes: A cross-sectional study

BACKGROUND

The combined effect of vitamin D and parathyroid hormone on glucose homeostasis has not been adequately investigated. The aim of this study was to examine the role of parathyroid hormone/vitamin D axis on glucose homeostasis in elderly persons with prediabetes.

METHODS

Patients with prediabetes ( n = 144) and healthy age-matched controls ( n = 81) were included in this cross-sectional study. Study parameters included anthropometric characteristics, morning fasting glucose (fasting plasma glucose), insulin (fasting plasma insulin), parathyroid hormone, 25-hydroxyvitamin D, homeostasis model assessment of insulin resistance and homeostasis model assessment of β-cell function. Both groups were stratified into subgroups according to vitamin D status and tertiles of parathyroid hormone.

RESULTS

Both groups were comparable in terms of body mass index, 25-hydroxyvitamin D and parathyroid hormone status. In the prediabetes group, fasting plasma glucose differed significantly across parathyroid hormone tertiles, increasing from the first to the third tertile ( p = 0.011). There were higher fasting plasma glucose values in participants with vitamin D deficiency/parathyroid hormone third tertile compared to all other groups ( p = 0.031, 0.027 and 0.039, respectively).

CONCLUSION

Parathyroid hormone status is associated with impaired glucose homeostasis; hypovitaminosis D combined with high parathyroid hormone concentrations are associated with glycaemic dysregulation in elderly patients with prediabetes.

Flavonoids, Dairy Foods, and Cardiovascular and Metabolic Health: A Review of Emerging Biologic Pathways

A growing body of nutritional science highlights the complex mechanisms and pleiotropic pathways of cardiometabolic effects of different foods. Among these, some of the most exciting advances are occurring in the area of flavonoids, bioactive phytochemicals found in plant foods; and in the area of dairy, including milk, yogurt, and cheese. Many of the relevant ingredients and mechanistic pathways are now being clarified, shedding new light on both the ingredients and the pathways for how diet influences health and well-being. Flavonoids, for example, have effects on skeletal muscle, adipocytes, liver, and pancreas, and myocardial, renal, and immune cells, for instance, related to 5'-monophosphate-activated protein kinase phosphorylation, endothelial NO synthase activation, and suppression of NF-κB (nuclear factor-κB) and TLR4 (toll-like receptor 4). Effects of dairy are similarly complex and may be mediated by specific amino acids, medium-chain and odd-chain saturated fats, unsaturated fats, branched-chain fats, natural trans fats, probiotics, vitamin K1/K2, and calcium, as well as by processing such as fermentation and homogenization. These characteristics of dairy foods influence diverse pathways including related to mammalian target of rapamycin, silent information regulator transcript-1, angiotensin-converting enzyme, peroxisome proliferator-activated receptors, osteocalcin, matrix glutamate protein, hepatic de novo lipogenesis, hepatic and adipose fatty acid oxidation and inflammation, and gut microbiome interactions such as intestinal integrity and endotoxemia. The complexity of these emerging pathways and corresponding biological responses highlights the rapid advances in nutritional science and the continued need to generate robust empirical evidence on the mechanistic and clinical effects of specific foods.

CRP Genotypes Predict Increased Risk to Co-Present with Low Vitamin D and Elevated CRP in a Group of Healthy Black South African Women

Low 25-hydroxyvitamin D (25(OH)D) and elevated C-reactive protein (CRP) concentrations are independently associated with adverse health outcomes, including cardiovascular disease (CVD). Although an inverse association between these factors has been described, the underlying mechanisms remain unknown. We postulate that environment-gene interactions, through which 25(OH)D interacts with single nucleotide polymorphisms (SNPs) within the CRP gene, modulate CRP; that certain CRP genotypes predispose individuals to a co-phenotype of low 25(OH)D and elevated CRP concentrations; and that this co-phenotype is associated with higher CVD risk. Twelve CRP SNPs were genotyped, and both 25(OH)D and CRP were quantified, in 505 black South African women. Alarmingly, 66% and 60% of the women presented with deficient/insufficient 25(OH)D and elevated CRP concentrations, respectively. CRP concentrations were higher in individuals with lower 25(OH)D concentrations. However, no 25(OH)D-CRP genotype interactions were evident. Several genotypes were associated with an altered risk of presenting with the co-phenotype, indicating a genetic predisposition. Women presenting with this co-phenotype had higher blood pressure and increased anthropometric measures, which may predispose them to develop CVD. We recommend increasing vitamin D fortification and supplementation efforts to reduce inflammation among black women with vitamin D deficiency, thereby possibly curbing diseases contingent on the co-phenotype described here.

Vascular pathology in multiple sclerosis: reframing pathogenesis around the blood-brain barrier

Blood-brain barrier (BBB) disruption has long been recognised as an important early feature of multiple sclerosis (MS) pathology. Traditionally, this has been seen as a by-product of the myelin-specific immune response. Here, we consider whether vascular changes instead play a central role in disease pathogenesis, rather than representing a secondary effect of neuroinflammation or neurodegeneration. Importantly, this is not necessarily mutually exclusive from current hypotheses. Vascular pathology in a genetically predisposed individual, influenced by environmental factors such as pathogens, hypovitaminosis D and smoking, may be a critical initiator of a series of events including hypoxia, protein deposition and immune cell egress that allows the development of a CNS-specific immune response and the classical pathological and clinical hallmarks of disease. We review the changes that occur in BBB function and cerebral perfusion in patients with MS and highlight genetic and environmental risk factors that, in addition to modulating immune function, may also converge to act on the vasculature. Further context is provided by contrasting these changes with other neurological diseases in which there is also BBB malfunction, and highlighting current disease-modifying therapies that may also have an effect on the BBB. Indeed, in reframing current evidence in this model, the vasculature could become an important therapeutic target in MS.

Tumor-linked HER2 expression: association with obesity and lipid-related microenvironment

Obesity is associated with the risk of several health disorders including certain cancers. Among obesity-related cancers, postmenopausal breast carcinoma is a well-studied one. Apart from an increase in certain types of lipids in obesity, excess adipose tissue releases many hormone-like cytokines/adipokines, which are usually pro-inflammatory in nature. Leptin is one of such adipokines and significantly linked with the intracellular signaling pathways of other growth factors such as insulin-like growth factor-1 (IGF-1), vascular endothelial growth factor (VEGF), human epidermal growth factor receptor 2 (HER2). In general, HER2 is overexpressed in roughly 30% of breast carcinomas; its presence indicates aggressive tumor behavior. Conversely, HER2 has certain effects in normal conditions such as differentiation of preadipocytes, cardiovascular health and vitamin D metabolism. HER2 has no known endogenous ligand, but it may form dimers with other three members of the epidermal growth factor receptor (EGFR) family and can activate downstream signaling pathways. Furthermore, HER2 is intimately connected with several enzymes, e.g. fatty acid synthase (FASN), phosphatidylinositol 3-kinase (PI3K), AKT and mechanistic target of rapamycin (mTOR), all of which play significant regulatory roles in lipogenic pathways or lipid metabolism. In obesity-related carcinogenesis, characteristics like insulin resistance and elevated IGF-1 are commonly observed. Both IGF-1 and leptin can modulate EGFR and HER2 signaling pathways. Although clinical studies have shown mixed results, the behavior of HER2+ tumor cells including HER2 levels can be altered by several factors such as obesity, leptin and fatty acids. A precise knowledge is useful in new therapeutic approaches against HER+ tumors.

Evaluation of vitamin D levels in relation to coronary CT angiographic findings in an Iranian population

Background

Vitamin D deficiency, as a predisposing factor for coronary artery disease (CAD), is a subject of increasing interest. However, its role as a risk factor has not been proven. This study aimed to investigate the relationship between serum vitamin D levels and CAD.

Materials and methods

Using a cross-sectional design, 180 patients who were candidates for coronary computed tomography angiography (CCTA) were selected. Serum levels of vitamin D were measured and compared with the results of CCTA (including calcium score, and presence and severity of coronary artery involvement due to atherosclerotic plaques).

Results

The mean age of the participants was 60.5±10.6 years and the mean serum vitamin D level was 26.2±15.9 ng/dL (range, 3.5–83.2 ng/dL). Overall, 6.1% of the participants (n=11) had vitamin D deficiency, 56.1% (n=101) had insufficient levels of vitamin D, and 37.8% (n=68) had sufficient levels of vitamin D. The mean serum vitamin D level was significantly lower in patients with severe CAD (P=0.004). The serum vitamin D level in the “positive for CAD” group was 20.98 ng/mL, significantly lower than the level in the “negative for CAD” group (30.47 ng/mL; P<0.001). The mean calcium score among participants was 533.5±87.9. Based on the Spearman test, a significant negative correlation (−0.21) was detected between the serum vitamin D level and coronary artery calcium score (CACS) (P=0.005). Conversely, the mean CACS in the vitamin D deficient group was significantly higher than in the insufficient and sufficient vitamin D groups (P<0.001 for both comparisons).

Conclusion

Vitamin D deficiency was associated with coronary artery calcification and severity of coronary artery stenosis in Iranian patients.

Influence of vitamin D levels on the cardiovascular profile of hypogonadal men

PURPOSE

A large body of evidence suggests a role for vitamin D in conditioning cardiovascular risk. Therefore, it can be hypothesized that vitamin D might also play a role in influencing the metabolic profile of hypogonadal men. In this work, we aimed at evaluating if any relationship exists between vitamin D levels and cardiovascular parameters in male hypogonadism.

METHODS

Hypogonadal patients attending our andrology unit were retrospectively reviewed. Clinical and biochemical parameters were evaluated.

RESULTS

103 patients were studied (51 non-diabetic and 52 diabetic subjects). Mean age of the whole sample was 65 years (standard error of the mean: 0.62). Significant correlations of age, total testosterone, parathyroid hormone (PTH), calcemia, and 25-OH vitamin D with the metabolic profile were found. In logistic regression models including age, total testosterone, PTH, calcemia and 25-OH vitamin D as independent variables, lower levels of 25-OH vitamin D were associated with high values of body mass index (BMI) [odds ratio (OR) 0.910, p 0.019], insulin (OR 0.918, p 0.034), homeostatic model assessment (HOMA) index (OR 0.918, p 0.030), total cholesterol (OR 0.819, p < 0.001), triglycerides (OR 0.820, p < 0.001), and low-density lipoprotein cholesterol (OR 0.923, p 0.034). In non-diabetic subjects, lower levels of 25-OH vitamin D were associated with high values of BMI, insulin, HOMA, triglycerides, systolic, and diastolic blood pressure. On the other hand, in diabetic subjects, lower levels of 25-OH vitamin D were associated with high values of total cholesterol and triglycerides.

CONCLUSIONS

Our work shows the influence of vitamin D on cardiovascular profile in male hypogonadism. This effect seems to be more relevant in non-diabetic subjects. If these data were to be confirmed, vitamin D assessment might become mandatory in the clinical evaluation of cardiovascular profile in male hypogonadism.

The role of vitamin D in male fertility: A focus on the testis

In the last decade, vitamin D has emerged as a pleiotropic molecule with a multitude of autocrine, paracrine and endocrine functions, mediated by classical genomic as well as non-classical non-genomic actions, on multiple target organs and systems. The expression of vitamin D receptor and vitamin D metabolizing enzymes in male reproductive system, particularly in the testis, suggests the occurrence of vitamin D synthesis and regulation as well as function in the testis. The role of vitamin D in the modulation of testis functions, including hormone production and spermatogenesis, has been investigated in animals and humans. Experimental studies support a beneficial effect of vitamin D on male fertility, by modulating hormone production through genomic and non-genomic actions, and, particularly, by improving semen quality essentially through non-genomic actions. However, clinical studies in humans are controversial. Indeed, vitamin D seems to contribute to the modulation of the bioavailable rather than total testosterone. Moreover, although an increased prevalence or risk for testosterone deficiency was reported in men with vitamin D deficiency in observational studies, the majority of interventional studies demonstrated the lack of effect of vitamin D supplementation on circulating levels of testosterone. The most consistent effect of vitamin D was reported on semen quality. Indeed, vitamin D was shown to be positively associated to sperm motility, and to exert direct actions on spermatozoa, including non-genomic driven modulation of intracellular calcium homeostasis and activation of molecular pathways involved in sperm motility, capacitation and acrosome reaction. The current review provides a summary of current knowledge on the role of vitamin D in male fertility, by reporting clinical and experimental studies in humans and animals addressing the relationship between vitamin D and testis function.

Effects of Orthodox religious fasting on human health: a systematic review

PURPOSE

Different studies have pointed towards a positive effect of religious fasting on human health. Orthodox fasting (OF) regime could be characterized as a periodical vegetarian diet, demonstrating several common characteristics with the typical Mediterranean diet. The present systematic review aimed to synthesize available results regarding the potential impact of OF on human health.

METHODS

Key biomedical databases were searched to identify studies examining the effects of OF on humans. Following implementation of specific criteria, ten studies were included in the analysis and their results were systematically reported and critically appraised in this review.

RESULTS

According to the available limited results, OF periods are characterized by a restriction in total energy and fat intake, an increase in carbohydrate and fiber consumption, while in terms of protein intake, results are contradictive. The overall effect of OF on lipids profile seems to be optimal, with the reduction of total cholesterol and LDL-C levels, being a consistent finding across studies (up to 17.8 and 31.4%, respectively). However, the effect on HDL-C is still unclear. Conclusions regarding the impact on body weight and glucose homeostasis cannot be drawn, given that relevant data are limited with conflicting results. Any potential negative aspects of OF, mainly attributed to reduced dietary intake of vitamin D and B12 and minerals (mainly calcium), require further investigation.

CONCLUSIONS

Given the limitations of available evidence, more studies are required before reaching definite conclusions about the effects of OF on human health.

Interleukin 17A in atherosclerosis - Regulation and pathophysiologic effector function

This review summarizes the current data on the interleukin (IL)-17A pathway in experimental atherosclerosis and clinical data. IL-17A is a prominent cytokine for early T cell response produced by both innate and adaptive leukocytes. In atherosclerosis, increased total IL-17A levels and expression in CD4⁺ T helper and γδ T cells have been demonstrated. Cytokines including IL-6 and TGFβ that increase IL-17A expression are elevated. Many other factors such as lipids, glucose and sodium chloride concentrations as well as vitamins and arylhydrocarbon receptor agonists that promote IL-17A expression are closely associated with cardiovascular risk in the human population. In acute inflammation models, IL-17A mediates innate leukocyte recruitment of both neutrophils and monocytes. In atherosclerosis, IL-17A increased aortic macrophage and T cell infiltration in most models. Secondary recruitment effects via the endothelium and according to recent data also pericytes have been demonstrated. IL-17 receptor A is highly expressed on monocytes and direct effects have been reported as well. Beyond leukocyte accumulation, IL-17A may affect other factors of plaque formation such as endothelial function, and according to some reports, fibrous cap formation and vascular relaxation with an increase in blood pressure. Anti-IL-17A agents are now available for clinical use. Cardiovascular side effect profiles are benign at this point. IL-17A appears to be a differential regulator of atherosclerosis and its effects in mouse models suggest that its modulation may have contradictory effects on plaque size and possibly stability in different patient populations.

Effects of Vitamin D Supplementation on IGF-1 and Calcitriol: A Randomized-Controlled Trial

Increasing evidence suggests a possible interaction between vitamin D and insulin-like growth factor-1 (IGF-1). We aimed to investigate effects of vitamin D supplementation on IGF-1 (primary outcome) and calcitriol (1,25(OH)₂D) concentrations (secondary outcome). This is a post-hoc analysis of the Styrian Vitamin D Hypertension Trial—a single-center, double-blind, randomized, placebo-controlled trial (RCT) conducted from 2011 to 2014 at the Medical University of Graz, Austria. Two-hundred subjects with arterial hypertension and 25(OH)D concentrations <30 ng/mL were randomized to either receive 2800 IU of vitamin D daily or placebo for eight weeks. A total of 175 participants (mean ± standard deviation age, 60 ± 11 years; 49% women) with available IGF-1 concentrations were included in the present analysis. At baseline, IGF-1 concentrations were significantly correlated with 1,25(OH)₂D (r = 0.21; p = 0.005) but not with 25(OH)D (r = −0.008; p = 0.91). In the RCT, vitamin D had no significant effect on IGF-1 (mean treatment effect 3.1; 95% confidence interval −5.6 to 11.9 ng/mL; p = 0.48), but it increased 1,25(OH)₂D concentrations (mean treatment effect 9.2; 95% confidence interval 4.4 to 13.9 pg/mL; p ≤ 0.001). In this RCT, in hypertensive patients with low 25(OH)D concentrations, there was no significant effect of vitamin D supplementation on IGF-1 concentrations. However, we observed a cross-sectional correlation between 1,25(OH)₂D and IGF-1 and an increase of 1,25(OH)₂D after vitamin D supplementation.

EFFECT OF ASTRAGALOSIDE ON VITAMIN D-RECEPTOR EXPRESSION AFTER ENDOTHELIN-1-INDUCED CARDIOMYOCYTE INJURY

BACKGROUND

Astragaloside, which is one of the main components of Astragalus membranaceus, has been widely used in the treatment of congestive heart failure in China, and it can protect cardiomyocytes. Its mechanism of action remains unclear. Therefore, the present study was carried out to investigate the influence of astragaloside on rat cardiomyocytes stimulated with endothelin-1 (ET-1), and explored the underlying mechanism.

MATERIALS AND METHODS

ET-1 was used to stimulate primary rat cardiomyocytes and establish a cardiomyocyte hypertrophy model. Different astragaloside doses were administered in combination with ET-1. Cardiomyocyte hypertrophy and apoptosis were examined using transmission electron microscopy (TEM) and flow cytometry, respectively. The molecular mechanism was explored by analyzing the mRNA of the vitamin D receptor (VDR), cytochrome P450 family 27 subfamily B member 1(CYP27B), cytochrome P450 family 24 subfamily A member 1(CYP24A) and renin mRNA levels by quantificational real-time polymerase chain reaction(qRT-PCR).

RESULTS

Rat cardiomyocyte hypertrophy model was established successfully. Astragaloside administration significantly affected cell apoptosis and significantly inhibited ET-1-induced cardiomyocyte hypertrophy in a dose-dependent manner. Astragaloside treatment affected the expression of signaling molecules in the vitamin D axis.

CONCLUSION

Astragaloside inhibits ET-1-induced cardiomyocyte hypertrophy. This effect can be reversed by regulating the levels of the relevant factors in the vitamin D axis.

Pharmacologic Treatment of Dyslipidemia in Diabetes: A Case for Therapies in Addition to Statins

PURPOSE OF REVIEW

The purpose of the study is to review the use of statins and the role of both non-statin lipid-lowering agents and diabetes-specific medications in the treatment of diabetic dyslipidemia.

RECENT FINDINGS

Statins have a primary role in the treatment of dyslipidemia in people with type 2 diabetes, defined as triglyceride levels >200 mg/dl and HDL cholesterol levels <40 mg/dL. A number of clinical trials suggest that treatment with a fibrate may reduce cardiovascular events. However, the results of these trials are inconsistent, probably because many of their participants did not have dyslipidemia. The choice of medications used to treat diabetes can have major implications regarding management of dyslipidemia; metformin, GLP-1 agonists, and pioglitazone all have favorable lipid effects. These agents, as well as the new SGLT2 inhibitors, may reduce cardiovascular events. Management of dyslipidemia in people with type 2 diabetes should start with statin therapy and optimal glycemic control with agents that have favorable lipid and cardiovascular effects. We believe that there is a role for adding fenofibrate to moderate-intensity statins in selected patients with true dyslipidemia. We propose an algorithm for selecting add-on medications for diabetes (after metformin) based on lipid status.