Relationship between vitamin D deficiency and cardiovascular disease

Selected Psychosocial Factors, Nutritional Behavior, and the Analysis of Concentrations of Selected Vitamins in Patients with Cardiovascular Diseases

Cardiovascular diseases (CVD) are the leading cause of death worldwide, influenced by the interaction of factors, including age, sex, genetic conditions, overweight/obesity, hypertension, an abnormal lipid profile, vitamin deficiencies, diabetes, and psychological factors. This study aimed to assess the relationships between psychosocial and nutritional factors in a group of 61 patients with CVD (i.e., atherosclerosis, hypertension, ischemic heart disease, and myocardial infarction) and their possible impact on the course of the disease. The plasma concentrations of vitamins A, E, D, and β-carotene were determined using validated HPLC-MS/MS, while the lipid profile was analyzed enzymatically. Psychosocial factors and nutritional behaviors were assessed using author-designed questionnaires. Over 50% of patients had 25-OH-D3 and retinol deficiencies, while >85% of patients exhibited significant deficiencies in α-tocopherol and β-carotene. The lipid profile showed no specific relationship with any particular CVD. Dietary behavior minimally impacted biochemical parameters except for higher β-carotene concentrations in the group with higher fruit and vegetable intake. The negative impact of the CVD on selected parameters of quality of life was noticed. To increase the effectiveness of the prevention and treatment of CVD, the need for interdisciplinary cooperation observed between doctors, psychologists, and specialists in human nutrition seems to be justified.

Low serum 25-hydroxyvitamin D (vitamin D) level among children with ventricular septal defect: how big is the risk for pulmonary hypertension?

INTRODUCTION

Ventricular septal defect is the most common CHD, leading to pulmonary hypertension. Significantly lower 25-hydroxyvitamin D level was reported in children with CHD compared with healthy controls. The current study aimed to investigate the correlation between 25-hydroxyvitamin D level and pulmonary hypertension in children with ventricular septal defect.

METHODS

A cross-sectional study was conducted on ventricular septal defect paediatric patients from January to June, 2019. Serum 25-hydroxyvitamin D was measured using electrochemiluminescence. Pulmonary hypertension was defined as mean pulmonary artery systolic pressure > 20 mmHg for children >3 months of age at sea level, measured by Doppler echocardiography.

RESULTS

From forty-four subjects, the majority of the subjects were female (56.8%) with normal nutritional status and perimembranous ventricular septal defect. Bivariate analysis showed that 25-hydroxyvitamin D level was associated with pulmonary hypertension (p < 0.01), type and size of ventricular septal defect (p = 0.02), and heart failure (p < 0.01). Higher 25-hydroxyvitamin D level was correlated with better nutritional status (p = 0.04, r = 0.26), and lower 25-hydroxyvitamin D level was correlated with the occurence of perimembranous ventricular septal defect (p = 0.01, r = -0.39), larger defect size (p < 0.01, r = -0.70), history of pneumonia (p = 0.02, r = -0.31), and heart failure (p < 0.01, r = -0.64). Subjects with 25-hydroxyvitamin D deficiency had prevalence ratio of 24.0 times for pulmonary hypertension. Higher pulmonary artery pressure was correlated to the occurence perimembranous ventricular septal defect (p = 0.01, r = 0.47), larger defect size (p < 0.01, r = 0.78), history of pneumonia (p = 0.01, r = 0.38), and heart failure (p < 0.01, r = 0.75).

CONCLUSION

Children with ventricular septal defect who had low 25-hydroxyvitamin D level posed a higher risk of having pulmonary hypertension.

Vitamin D Deficiency Is Inversely Associated with Homeostatic Model Assessment of Insulin Resistance

The study was conducted to comprehensively assess the association of the concentration of vitamin D in the blood and insulin resistance in non-diabetic subjects. The objective was to pool the results from all observational studies from the beginning of 1980 to August 2021. PubMed, Medline and Embase were systematically searched for the observational studies. Filters were used for more focused results. A total of 2248 articles were found after raw search which were narrowed down to 32 articles by the systematic selection of related articles. Homeostatic Model Assessment of Insulin Resistance (HOMAIR) was used as the measure of insulin resistance and correlation coefficient was used as a measure of the relationship between vitamin D levels and the insulin resistance. Risk of bias tables and summary plots were built using Revman software version 5.3 while Comprehensive meta-analysis version 3 was used for the construction of forest plot. The results showed an inverse association between the status of vitamin D and insulin resistance (r = -0.217; 95% CI = -0.161 to -0.272; p = 0.000). A supplement of vitamin D can help reduce the risk of insulin resistance; however further studies, like randomized controlled trials are needed to confirm the results.

Effectiveness of Some Vitamins in the Prevention of Cardiovascular Disease: A Narrative Review

By virtue of their regulatory role in various metabolic and biosynthetic pathways for energy status and cellular integrity, both hydro-soluble and lipo-soluble vitamins are considered to be involved in maintaining cardiovascular function in health and disease. Deficiency of some vitamins such as vitamin A, B₆, folic acid, C, D, and E has been shown to be associated with cardiovascular abnormalities whereas supplementation with these vitamins has been claimed to reduce cardiovascular risk for hypertension, atherosclerosis, myocardial ischemia, arrhythmias, and heart failure. However, the data from several experimental and clinical studies for the pathogenesis of cardiovascular disease due to vitamin deficiency as well as therapy due to different vitamins are conflicting. In this article, we have attempted to review the existing literature on the role of different vitamins in cardiovascular disease with respect to their deficiency and supplementation in addition to examining some issues regarding their involvement in heart disease. Although both epidemiological and observational studies have shown some merit in the use of different antioxidant vitamins for the treatment of cardiovascular disorders, the results are not conclusive. Furthermore, in view of the complexities in the mechanisms of different cardiovascular disorders, no apparent involvement of any particular vitamin was seen in any specific cardiovascular disease. On the other hand, we have reviewed the evidence that deficiency of vitamin B₆ promoted KCl-induced Ca²⁺ entry and reduced ATP-induced Ca²⁺-entry in cardiomyocytes in addition to decreasing sarcolemmal (SL) ATP binding. The active metabolite of vitamin B₆, pyridoxal 5′-phosphate, attenuated arrhythmias due to myocardial infarction (MI) as well as cardiac dysfunction and defects in the sarcoplasmic reticulum (SR) Ca²⁺-transport in the ischemic-reperfused hearts. These observations indicate that both deficiency of some vitamins as well as pretreatments with different vitamins showing antioxidant activity affect cardiac function, metabolism and cation transport, and support the view that antioxidant vitamins or their metabolites may be involved in the prevention rather than the therapy of cardiovascular disease.

Vitamin D Deficiency as an Independent Predictor of Myocardial Infarction in the Elderly

Cardiovascular diseases are among the most common causes of disability and death in the world, and the number of patients with this category of diseases is increasing every year. This study aimed to investigate the role of vitamin D and the problems caused by its deficiency on the cardiovascular system. Level of D-(25(OH]D) in blood was studied by enzyme immunoassay in 95 elderly patients with myocardial infarction (MI) (the main group) and 92 elderly patients with no history of MI. The level of lipid metabolism as an indicator was determined using a KoneLab 300 auto-analyzer. Based on the results of this study, it was found that the elderly group without MI had the highest amount of D-(25(OH]D)(24.5±1.2), compared to the elderly group with MI (14.8±1.3). The rates of expressed deficiency, deficiency, and insufficiency in the group of elderly with MI were 53.6±5.1, 23.2±4.4, and 12.6±3.4%, respectively. This experiment has shown that D-(25(OH]D) is involved in lipid metabolism and reduces the accumulation of cholesterol by macrophages. The content of vitamin D in blood plasma was a prognostic predictor of MI, which improved MI in the elderly. Regardless of pathological changes, the deficit level of D-(25(OH]D) should be considered a laboratory predictor of MI in the elderly.

The Protective Effect of 1,25(OH)2D3 on Myocardial Function is Mediated via Sirtuin 3-Regulated Fatty Acid Metabolism

Energy substrate imbalance is a major cause of cardiac dysfunction. Vitamin D/vitamin D receptor (VD/VDR) deficiency is involved in the pathogenesis of various cardiac diseases; however, the exact underlying mechanism remains unclear. The aim of this study was to investigate whether vitamin D modulates mitochondrial fatty acid oxidase via sirtuin 3 signaling to protect the myocardium. 1-Alpha-hydroxylase-defficient mice exhibited a high metabolic rate and lower myocardial contractility than wild-type mice. Sirtuin 3 upregulation was detected in high-fat diet-fed mice receiving vitamin D3 compared with that in high-fat diet-fed mice. Both sirtuin 3 blockade and knockout inhibited the VD/VDR-induced downregulation of fatty acid oxidase in myocardial mitochondria. VD/VDR suppressed fatty acid metabolism by upregulating sirtuin 3 and lowering mitochondrial fat uptake, thereby improving myocardial function and balancing energy substrates, rather than by altering fat endocytosis and exocytosis.

Effect of Improving Dietary Structure on Serum 25(OH)VitD₃ Level in Hypertensive Patients in a Chinese Rural Area

Background

In this study, we explored the effect of an improved dietary pattern on 25-hydroxyvitamin D₃ [25(OH)VitD₃] level in hypertensive patients in a rural setting and investigated the possible mechanism for lowering blood pressure.

Material/Methods

Thirty-three participants with overweight or obesity were randomly divided into 2 groups. A 24-h dietary review method was used for dietary assessment. Participants in both groups were provided the same balanced diet except for the breakfast staple food for 4 weeks. General characteristics, body composition analysis, blood pressure, serum lipid profile, inflammatory indices, and serum 25(OH)VitD₃ level were assessed at baseline and at the completion of the 4-week dietary intervention. Nutrient intake was analyzed by dietary analysis software, and SPSS software was used for correlation and regression analyses.

Results

Thirty-one participants completed the study. The prevalence of vitamin D deficiency was 100% at baseline. After the dietary intervention, the prevalence of vitamin D deficiency decreased to 45%. Levels of dietary intake of vitamin D, cholesterol, protein, fat, and calcium showed a significantly positive correlation with the serum 25(OH)VitD₃ level. Body fat, visceral fat, waist-to-hip ratio, serum triglyceride, and Toll-2 expression were negatively correlated with the serum 25(OH)VitD₃ level. Blood pressure had a significant negative correlation with 25(OH)VitD₃ level. Participants in both groups experienced a significant decrease in blood pressure.

Conclusion

Intake of a balanced diet rich in vitamin D, with appropriate amounts of cholesterol, protein, calcium, and fat, helped improve body composition, ameliorated lipid metabolism disorder, reduced inflammation, and improved serum 25(OH)VitD₃ level, thus lowering blood pressure.

Study of vitamin D receptor gene polymorphisms in a cohort of myocardial infarction patients with coronary artery disease

Background

Vitamin D deficiency is associated with cardiovascular diseases, including coronary artery diseases (CAD). As vitamin D manifests its biological function through its vitamin D receptor (VDR), VDR gene polymorphisms potentially affect VDR functionality and vitamin D activity. Therefore, the objective of this study was to analyze three well-studied VDR gene polymorphisms—Fok1 (rs2228570), BsmI (rs1544410) and Taq1 (rs731236)—in a cohort of CAD patients after acute myocardial infarction.

Methods

In the presented cross-sectional study, 155 participants with CAD after acute myocardial infarction and 104 participants in a control group without CAD were enrolled. The participants in both groups were Caucasians of European origin. The genotyping of VDR polymorphisms rs2228570, rs1544410 and rs731236 was assessed by RT-PCR.

Results

The results show an association between the T/T genotype of the BsmI (rs1544410) and the G/G genotype of the Taq1 (rs731236) VDR polymorphism and CAD patients after acute myocardial infarction. There was no association between the Fok1 (rs2228570) VDR polymorphism and CAD patients after acute myocardial infarction.

Conclusion

The presented results suggest a potential association of the BsmI (rs1544410) and Taq1 (rs731236) VDR polymorphisms with CAD patients after myocardial infarction.

Supplementary Information

The online version contains supplementary material available at 10.1186/s12872-021-01959-x.

Geographic components of SARS-CoV-2 expansion: a hypothesis

The emergence of COVID-19 infection (caused by the SARS-CoV-2 virus) in Wuhan, China in the latter part of 2019 has, within a relatively short time, led to a global pandemic. Amidst the initial spread of SARS-CoV-2 across Asia, an epidemiologic trend emerged in relation to high altitude (HA) populations. Compared with the rest of Asia, SARS-CoV-2 exhibited attenuated rates of expansion with limited COVID-19 infection severity along the Tibetan plateau. These characteristics were soon evident in additional HA regions across Bolivia, central Ecuador, Nepal, Bhutan, and the Sichuan province of mainland China. This mini-review presents a discussion surrounding attributes of the HA environment, aspects of HA physiology, as well as, genetic variations among HA populations which may provide clues for this pattern of SARS-CoV-2 expansion and COVID-19 infection severity. Explanations are provided in the hypothetical, albeit relevant historical evidence is provided to create a foundation for future research.

The association of megalin and cubilin genetic variants with serum levels of 25-hydroxvitamin D and the incidence of acute coronary syndrome in Egyptians: A case control study

Megalin and cubilin are two receptors that mediate endocytosis of 25-hydroxyvitamin D (25(OH)D) for its final activation by hydroxylation. The aim of the present study was to evaluate the association of polymorphisms in megalin (rs2075252 and rs4668123) and cubilin (rs1801222 and rs12766939) with the circulating serum levels of 25(OH)D and with the early incidence of acute coronary syndrome (ACS) in Egyptians. The study included 328 subjects; 185 ACS patients aged between 27 and 60 years, and 143 healthy age-matched controls. Genotyping of cubilin rs12766939 Single Nucleotide Polymorphism (SNP) was performed using Real-Time Polymerase Chain Reaction (qPCR) and for megalin rs4668123 and rs2075252 and cubilin rs1801222 by Polymerase Chain Reaction- Restriction Fragment Length Polymorphism (PCR-RFLP). 25(OH)D levels were measured by Ultra Performance Liquid Chromatography- Tandem Mass Spectroscopy (UPLC-MS/MS). Results showed that vitamin D deficiency was highly linked to ACS incidence (P < 0.0001). The megalin rs4668123 CC, cubilin rs1801222 GG and cubilin rs12766939 GG + GA genotypes are associated with a higher ACS incidence and can be considered risk factors, according to Chi-squared test (P = 0.0003, 0.0442, 0.013 respectively). Conversely, the megalin rs2075252 SNP was not associated with increased ACS incidence. However, after performing multiple logistic regression analysis, only the megalin rs4668123 SNP was considered an independent ACS risk factor. Furthermore, the megalin rs4668123 CC genotype was associated with lower 25(OH)D levels (P = 0.0018). In conclusion, megalin rs4668123 (CC) was linked to lower 25(OH)D levels and can be considered an independent risk factor for incidence of ACS.

Vitamin D-binding protein (rs4588) T/T genotype is associated with anteroseptal myocardial infarction in coronary artery disease patients

Background

Cardiovascular diseases (CVD) are among leading causes of death worldwide and amongst CVD, coronary artery disease (CAD) accounts for almost half of all cardiovascular deaths as the most common cause of death in the developed world. Vitamin D and the vitamin D-binding protein (VDBP) have been studied as possible CAD pathogenesis factors but literature data provide opposing evidence on their role in CAD. Herein we aimed to present novel evidence on the association of two VDBP polymorphisms (rs4588) and (rs7041) with CAD in patients after acute myocardial infarction and study possible correlations of these polymorphisms with 25-hydroxyvitamin D [25(OH)D] serum levels.

Methods

The cross-section genotyping study included 155 subjects with CAD upon acute myocardial infarct and 104 control subjects. All patients and control group were Caucasians of European descent. VDBP polymorphisms (rs4588) and (rs7041) were studied by use of RT-PCR. Liquid chromatography, tandem mass spectrometry (LC-MS/MS) method was used for measurement of vitamin D in the serum.

Results

Association of the VDBP (rs4588) T/T genotype with CAD patients after acute MI and correlation of VDBP (rs4588) genotype G/G with higher levels of total vitamin D were found. No correlation of 25(OH)D serum levels with CAD were established but the multivariate logistic regression modelling enabled association of total vitamin D level and VDBP (rs4588) T/T genotype with CAD and anteroseptal myocardial infarction (ASMI) CAD occurrence.

Conclusions

Obtained data speak in favor to the VDBP (rs4588) T/T genotype as a susceptibility factor for anteroseptal myocardial infarction where the same genotype showed to be generally more prevalent in smokers.

Vitamin D and macrophage polarization in epicardial adipose tissue of atherosclerotic swine

Vitamin D functions as a potent immunomodulator by interacting with many immune cells however, its role in regulating inflammation in the epicardial adipose tissue (EAT) is unclear. In the EAT of atherosclerotic microswine that were fed with deficient, sufficient or supplemented levels of vitamin D, we evaluated the phenotype of the macrophages. Vitamin D treatment was continued for 12 months and serum 25(OH)D levels were measured regularly. Infiltration of M1/M2 macrophage was investigated by immunostaining for CCR7 and CD206, respectively in conjunction with a pan macrophage marker CD14. Significant difference in the number of CCR7+ cells was observed in the EAT from vitamin D-deficient swine compared to vitamin D-sufficient or -supplemented swine. Expression of CD206 correlated with high levels of serum 25(OH)D indicating a significant increase in M2 macrophages in the EAT of vitamin D-supplemented compared to -deficient swine. These findings suggest that vitamin D-deficiency exacerbates inflammation by increasing pro-inflammatory M1 macrophages, while vitamin D-supplementation attenuates the inflammatory cytokines and promotes M2 macrophages in EAT. This study demonstrates the significance of vitamin D mediated inhibition of macrophage mediated inflammation in the EAT during coronary intervention in addition to its immunomodulatory role. However, additional studies are required to identify the cellular mechanisms that transduce signals between macrophages and smooth muscle cells during restenosis in the presence and absence of vitamin D.

Dietary Calcium Intake May Contribute to the HOMA-IR Score in Korean Females with Vitamin D Deficiency (2008-2012 Korea National Health and Nutrition Examination Survey)

Background

Vitamin D and calcium are important factors involved in the regulation of blood glucose and insulin secretion. The Homeostatic Model Assessment of Insulin Resistance (HOMA-IR) score is a useful variable for evaluating insulin resistance, and therefore we cross-sectionally compared HOMA-IR scores according to serum vitamin D levels and dietary calcium intake.

Methods

We selected data from healthy males (n=5,163) and females (n=7,506) analyzed over 5 years (2008–2012) via the Korea National Health and Nutrition Examination Survey (KNHANES). We calculated HOMA-IR scores and compared them according to serum 25-hydroxyvitamin D (25(OH)D) concentration classification (<20, 20–30, >30 ng/mL) and dietary calcium quintile after adjustment for relevant variables using complex sample analysis. Comparisons were done after data weighting.

Results

The mean dietary calcium intake in males and females was 558.1 mg/day and 445.9 mg/day, respectively. The mean serum 25(OH)D concentration in males and females was 19.4 ng/mL and 16.8 ng/mL, respectively. After adjustment for relevant variables, HOMA-IR score was significantly correlated with serum 25(OH)D concentration and dietary calcium intake in females, whereas it was only correlated with serum 25(OH)D concentration in males. HOMA-IR was significantly lower in the top quintile of dietary calcium intake (mean, 866 mg/day) within females with vitamin D deficiency (P=0.047).

Conclusion

Adequate dietary calcium intake may be important for normal HOMA-IR in females with vitamin D deficiency.

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

Introduction

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

Material and methods

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

Results

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

Conclusions

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

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.

The association between serum ferritin and 25-hydroxyvitamin D and metabolic syndrome in Korean women: the Korea National Health and Nutrition Examination Survey 2010-2012

The present study was conducted to assess the association between serum ferritin and 25-hydroxyvitamin D [25(OH)D] and metabolic syndrome (MetS) in Korean women. The data of a total of 9,256 adults (6,960 women without MetS and 2,296 women with MetS) aged ≥20 years from the Fifth Korean National Health and Nutrition Examination Survey (KNHANES V) (2010–2012) were analyzed. A covariance test adjusted for covariates was performed for serum ferritin levels in relation to vitamin D (vitamin D deficiency, 25(OH)D <10.0 ng/ml; vitamin D insufficiency, 25(OH)D ≥10.0, <20.0 ng/ml; vitamin D sufficiency, 25(OH)D ≥20.0 ng/ml). The key study results were as follows: First, in women without MetS, after adjusting for related variables (smoking, alcohol drinking, regular exercise, current menstruation, hormonal contraceptives, hormone-replacement therapy, SBP, DBP, BMI, WM, TC, TGs, HDL-C, FPG, AST, ALT, and age), vitamin D was positively associated with serum ferritin levels (p<0.001). Second, in women with MetS, after adjusting for related variables (except age), vitamin D was positively associated with serum ferritin levels (p = 0.041). However, when further adjusted for age, vitamin D was not associated with serum ferritin levels (p = 0.293). In conclusion, vitamin D was positively associated with serum ferritin levels in women without MetS but not in women with MetS.

The association between serum ferritin and 25-hydroxyvitamin D and metabolic syndrome in Korean women: the Korea National Health and Nutrition Examination Survey 2010-2012

The present study was conducted to assess the association between serum ferritin and 25-hydroxyvitamin D [25(OH)D] and metabolic syndrome (MetS) in Korean women. The data of a total of 9,256 adults (6,960 women without MetS and 2,296 women with MetS) aged ≥20 years from the Fifth Korean National Health and Nutrition Examination Survey (KNHANES V) (2010-2012) were analyzed. A covariance test adjusted for covariates was performed for serum ferritin levels in relation to vitamin D (vitamin D deficiency, 25(OH)D <10.0 ng/ml; vitamin D insufficiency, 25(OH)D ≥10.0, <20.0 ng/ml; vitamin D sufficiency, 25(OH)D ≥20.0 ng/ml). The key study results were as follows: First, in women without MetS, after adjusting for related variables (smoking, alcohol drinking, regular exercise, current menstruation, hormonal contraceptives, hormone-replacement therapy, SBP, DBP, BMI, WM, TC, TGs, HDL-C, FPG, AST, ALT, and age), vitamin D was positively associated with serum ferritin levels (p<0.001). Second, in women with MetS, after adjusting for related variables (except age), vitamin D was positively associated with serum ferritin levels (p = 0.041). However, when further adjusted for age, vitamin D was not associated with serum ferritin levels (p = 0.293). In conclusion, vitamin D was positively associated with serum ferritin levels in women without MetS but not in women with MetS.

Gender difference in relationship between serum ferritin and 25-hydroxyvitamin D in Korean adults

BACKGROUND

The present study was conducted to assess the gender difference in the relationship between serum ferritin and 25-hydroxyvitamin D [25(OH)D] in Korean adults.

METHODS

A total of 5,147 adults (2,162 men, 1,563 premenopausal women, and 1,422 postmenopausal women) aged ≥ 20 years from the Korean National Health and Nutrition Examination Survey (KNHANES) data (2012) were analyzed. A covariance test adjusted for covariates was performed for serum ferritin levels in relation to vitamin D status (vitamin D deficiency, 25(OH)D < 10.0 ng/mL; vitamin D insufficiency, 25(OH)D ≥ 10.0, < 20.0 ng/mL; vitamin D sufficiency, 25(OH)D ≥ 20.0 ng/mL).

RESULTS

The key study results were as follows: First, in men, in terms of serum ferritin levels by serum 25(OH)D level after adjusting for age, smoking, alcohol drinking, regular exercise, SBP, DBP, WM. TC, TGs, HDL-C, FPG, Hb, Hct, MCV, and Fe, serum ferritin levels were inversely increased with the increasing of serum 25(OH)D level (P = 0.012). Second, in premenopausal women, after adjusting for related variables, serum ferritin levels were increased with the increasing of serum 25(OH)D level (P = 0.003). Third, in postmenopausal women, after adjusting for related variables, serum ferritin levels were not significantly increased with the increasing of serum 25(OH)D level (P = 0.456).

CONCLUSION

Serum 25(OH)D level was inversely associated with the serum ferritin levels in men, but was positively associated with the serum ferritin levels in premenopausal women, and was not associated with the serum ferritin levels in postmenopausal women.

Vitamin D, PTH and the risk of overall and disease-specific mortality: Results of the Longitudinal Aging Study Amsterdam

Observational studies suggest that low concentrations of serum 25-hydroxyvitamin D (25(OH)D) and high concentrations of parathyroid hormone (PTH) are associated with a higher risk of mortality. The aim of this study was to examine whether 25(OH)D and PTH concentrations are independently associated with overall and disease-specific (cardiovascular and cancer-related) mortality in a large, prospective population-based cohort of older adults. Data from 1317 men and women (65-85 years) of the Longitudinal Aging Study Amsterdam were used. Cox proportional hazard analyses were used to examine whether 25(OH)D and PTH at baseline were associated with overall mortality (with a follow-up of 18 years) and disease-specific mortality (with a follow-up of 13 years). Compared to persons in the reference category of ≥75nmol/L, persons with serum 25(OH)D <25nmol/L (HR 1.46; 95% CI: 1.12-1.91) and 25-49.9nmol/L (HR 1.24; 95% CI: 1.01-1.53) had a significantly higher risk of overall mortality, as well as men with baseline PTH concentrations ≥7pmol/L (HR 2.54 (95% CI: 1.58-4.08)), compared to the reference category of <2.33pmol/L. The relationship of 25(OH)D with overall mortality was partly mediated by PTH. Furthermore, men with PTH concentrations of ≥7pmol/L (HR 3.22; 95% CI: 1.40-7.42) had a higher risk of cardiovascular mortality, compared to the reference category. No significant associations of 25(OH)D or PTH with cancer-related mortality were observed. Both 25(OH)D and PTH should be considered as important health markers.

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

Objective:

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

Methods:

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

Results:

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

Conclusion:

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

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

Background:

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

Aim:

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

Materials and Methods:

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

Results:

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

Conclusion:

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

Biochemical Assessment of Bone Health in Working Obese Egyptian Females with Metabolic Syndrome; the Effect of Weight Loss by Natural Dietary Therapies

AIM:

To investigate the relation between bone parameters and the metabolic syndrome criteria, before and after the administration of two different natural dietary supplements in middle aged working obese Egyptian women suffering from metabolic syndrome (MetS).

SUBJECTS AND METHODS:

Fifty eight middle aged obese female volunteers suffering from metabolic syndrome were divided into two groups. During the first period, group (A) consumed a low caloric diet and nutritional supplement consisting of doum flour biscuits, while group (B) consumed whole meal wheat flour biscuit with the same instructions. During the second period, both supplements were omitted. Assessment of blood pressure, relevant anthropometric parameters, lipid accumulation product, fasting blood glucose, uric acid, 25 hydroxy vitamin D (25 (OH) D), parathyroid hormone (PTH) and bone-specific alkaline phosphatase were performed.

RESULTS:

Data showed that although both supplements improved the MetS criteria and the bone health parameters, the supplement containing the doum flour proved to be more effective.

CONCLUSION:

These results confirm the benefit of doum in improving bone health parameter [25 (OH) D/PTH axis] in the MetS patients, beside the MetS criteria. So, we can conclude that natural effective supplements lead towards the optimization of biochemical parameters in favor of a healthy outcome.

VITamin D supplementation in renAL transplant recipients (VITALE): a prospective, multicentre, double-blind, randomized trial of vitamin D estimating the benefit and safety of vitamin D3 treatment at a dose of 100,000 UI compared with a dose of 12,000 UI in renal transplant recipients: study protocol for a double-blind, randomized, controlled trial

Background

In addition to their effects on bone health, high doses of cholecalciferol may have beneficial non-classic effects including the reduction of incidence of type 2 diabetes mellitus, cardiovascular disease, and cancer. These pleiotropic effects have been documented in observational and experimental studies or in small intervention trials. Vitamin D insufficiency is a frequent finding in renal transplant recipients (RTRs), and this population is at risk of the previously cited complications.

Methods/design

The VITALE study is a prospective, multicentre, double-blind, randomized, controlled trial with two parallel groups that will include a total of 640 RTRs. RTRs with vitamin D insufficiency, defined as circulating 25-hydroxyvitamin D levels of less than 30 ng/ml (or 75 nmol/l), will be randomized between 12 and 48 months after transplantation to blinded groups to receive vitamin D₃ (cholecalciferol) either at high or low dose (respectively, 100,000 UI or 12,000 UI every 2 weeks for 2 months then monthly for 22 months) with a follow-up of 2 years. The primary objective of the study is to evaluate the benefit/risk ratio of high-dose versus low-dose cholecalciferol on a composite endpoint consisting of de novo diabetes mellitus; major cardiovascular events; de novo cancer; and patient death. Secondary endpoints will include blood pressure (BP) control; echocardiography findings; the incidences of infection and acute rejection episodes; renal allograft function using estimated glomerular filtration rate; proteinuria; graft survival; bone mineral density; the incidence of fractures; and biological relevant parameters of mineral metabolism.

Discussion

We previously reported that the intensive cholecalciferol treatment (100 000 IU every 2 weeks for 2 months) was safe in RTR. Using a pharmacokinetic approach, we showed that cholecalciferol 100,000 IU monthly should maintain serum 25-hydroxyvitamin D at above 30 ng/ml but below 80 ng/ml after renal transplantation. Taken together, these results are reassuring regarding the safety of the cholecalciferol doses that will be used in the VITALE study. Analysis of data collected during the VITALE study will demonstrate whether high or low-dose cholecalciferol is beneficial in RTRs with vitamin D insufficiency.

Trial registration

ClinicalTrials.gov Identifier: NCT01431430.

Electronic supplementary material

The online version of this article (doi:10.1186/1745-6215-15-430) contains supplementary material, which is available to authorized users.

Evaluation of left ventricle functions by tissue Doppler, strain, and strain rate echocardiography in patients with primary hyperparathyroidism

Cardiovascular morbidity and mortality are increased in patients with primary hyperparathyroidism (PHPT). We aimed to evaluate left ventricle systolic and diastolic functions with tissue Doppler imaging (TDI) and strain and strain rate echocardiography in patients with PHPT. Thirty-one patients with PHPT and 29 healthy controls were evaluated with conventional and pulse Doppler echocardiography, TDI and strain and strain rate echocardiography. Myocardial performance index (MPI) was calculated. Strain and peak systolic strain rate in mid and basal segments of lateral, anterior, inferior, and septal walls of left ventricle were determined. TDI showed similar late diastolic myocardial peak velocity in two groups. Peak systolic mitral annular velocity, early diastolic myocardial peak velocity, and ratio of early to late diastolic myocardial peak velocity were lower in PHPT patients (p = 0.01, p < 0.001 and p < 0.001, respectively). MPI calculated by TDI was 0.53 ± 0.15 in PHPT group and 0.44 ± 0.09 in control group (p = 0.013). Strain values were lower in mid and basal segments of septum, lateral and anterior walls, and basal segment of inferior wall in PHPT patients. Mean systolic strain was -20.88 ± 2.30 and -24.25 ± 2.13 in PHPT patients and control group, respectively (p < 0.001). Mean strain rate was lower in PHPT patients compared to control group (-1.38 ± 0.19 vs -1.57 ± 0.25) (p = 0.002). Patients with PHPT, but no cardiac symptoms or documented cardiovascular disease, have subclinical systolic and diastolic myocardial dysfunction. Evaluation of these patients with TDI and S and Sr echocardiography in addition to conventional echocardiography might be valuable to detect subclinical cardiac involvement.

Effects of living at higher altitudes on mortality: a narrative review

Beside genetic and life-style characteristics environmental factors may profoundly influence mortality and life expectancy. The high altitude climate comprises a set of conditions bearing the potential of modifying morbidity and mortality of approximately 400 million people who are permanently residing at elevations above 1500 meters. However, epidemiological data on the effects of high altitude living on mortality from major diseases are inconsistent probably due to differences in ethnicity, behavioral factors and the complex interactions with environmental conditions. The available data indicate that residency at higher altitudes are associated with lower mortality from cardiovascular diseases, stroke and certain types of cancer. In contrast mortality from COPD and probably also from lower respiratory tract infections is rather elevated. It may be argued that moderate altitudes are more protective than high or even very high altitudes. Whereas living at higher elevations may frequently protect from development of diseases, it could adversely affect mortality when diseases progress. Corroborating and expanding these findings would be helpful for optimization of medical care and disease management in the aging residents of higher altitudes.

Vitamin D supplementation and lipid profile: what does the best available evidence show?

Vitamin D supplements have increasingly been used for the treatment and prevention of osteoporosis. Historically, effects of the vitamin on the cardiovascular (CV) system have been proposed and demonstrated in the literature, including benefits on serum lipids. Although observational studies support an association between increased serum vitamin D levels and a favorable lipid profile, interventional studies have shown no effects. This review presents and analyzes all the related randomized controlled trials (RCTs) identified in the literature from 1987 to present. A systematic literature search was conducted via MEDLINE, Cochrane Library and EMBASE and, out of 19 relevant RCTs identified, only one reported benefits of vitamin D supplementation on lipid profile parameters, while the rest showed no effects or even adverse outcomes, which are highlighted by the only meta-analysis in the field. Attempts to explain the paradox of beneficial findings of observational studies versus discouraging results of interventional studies have been made and the most popular suggests that high serum vitamin D concentrations may not be the cause of good health but its outcome instead, as healthy people are more likely to stay outdoors longer and have better eating habits. For definitive answers to be given, large, well-designed RCTs need to be conducted that will take into account and adjust for dietary consumption as well as serum calcium and parathyroid hormone levels, both of which have been shown to be associated with the CV system. Until then, recommendations for vitamin D supplementation should not change.

Mean platelet volume and vitamin D level

BACKGROUND

Vitamin D deficiency and a high mean platelet volume (MPV) are related to cardiovascular disease. We investigated whether vitamin D deficiency is associated with high MPV.

METHODS

This study included 434 patients without chronic disease who were not taking vitamin D or calcium supplements. Vitamin D was measured by chemiluminescent microparticle immunoassay on the Architect-I2000 system (Abbott Diagnostics, USA), and MPV was measured on the Cell-Dyn Ruby analyzer (Abbott Diagnostics). Patients were divided into Groups 1 (138 [men/women, 46/92]), 2 (148 [men/women, 54/94]), and 3 (148 [men/women, 50/98]) according to vitamin D levels of <10 ng/mL, 10-20 ng/mL, and >20 ng/mL, respectively.

RESULTS

The vitamin D level in Group 1 (7.7±1.9 ng/mL) was lower than that in Group 2 (15.1±1.6 ng/mL, P<0.001) and Group 3 (25.6±6.3 ng/mL, P<0.001). The MPV in Group 3 (7.5±1.0 fL) was lower than that in Group 1 (8.1±1.1 fL, P<0.001) and Group 2 (7.9±1.0 fL, P=0.009). Linear regression analysis showed that low levels of vitamin D (β=-0.109, P=0.019) was independently associated with increased MPV.

CONCLUSIONS

There was a strong association between a low vitamin D level and a high MPV; therefore, vitamin D deficiency may be associated with increased MPV.

Mean platelet volume and vitamin D level

BACKGROUND

Vitamin D deficiency and a high mean platelet volume (MPV) are related to cardiovascular disease. We investigated whether vitamin D deficiency is associated with high MPV.

METHODS

This study included 434 patients without chronic disease who were not taking vitamin D or calcium supplements. Vitamin D was measured by chemiluminescent microparticle immunoassay on the Architect-I2000 system (Abbott Diagnostics, USA), and MPV was measured on the Cell-Dyn Ruby analyzer (Abbott Diagnostics). Patients were divided into Groups 1 (138 [men/women, 46/92]), 2 (148 [men/women, 54/94]), and 3 (148 [men/women, 50/98]) according to vitamin D levels of <10 ng/mL, 10-20 ng/mL, and >20 ng/mL, respectively.

RESULTS

The vitamin D level in Group 1 (7.7±1.9 ng/mL) was lower than that in Group 2 (15.1±1.6 ng/mL, P<0.001) and Group 3 (25.6±6.3 ng/mL, P<0.001). The MPV in Group 3 (7.5±1.0 fL) was lower than that in Group 1 (8.1±1.1 fL, P<0.001) and Group 2 (7.9±1.0 fL, P=0.009). Linear regression analysis showed that low levels of vitamin D (β=-0.109, P=0.019) was independently associated with increased MPV.

CONCLUSIONS

There was a strong association between a low vitamin D level and a high MPV; therefore, vitamin D deficiency may be associated with increased MPV.

Vitamin d and its relationship with obesity and muscle

The skin synthesis of vitamin D represents the first step of a metabolic pathway whose features have been extensively studied and clarified in the last decades. In particular, the production of active and inactive forms of the hormone and the actions of the corresponding enzymes have offered new insights into the knowledge of vitamin D metabolism. Additionally, the description of the different organs and tissues expressing the vitamin D receptor and its possible functions, as well as its genetic determinants, have allowed focusing on the interrelationship between vitamin D and many physiological and pathological functions. In this context, many studies reported the association between vitamin D and adipose tissue metabolism, as well as the possible role of the hormone in obesity, weight, and fat mass distribution. Finally, many reports focused on the vitamin D-related effects on skeletal muscle, particularly on the mechanisms by which vitamin D could directly affect muscle mass and strength. This paper is mainly aimed to review vitamin D metabolism and its relationship with obesity and skeletal muscle function.