Vitamin D status and parathyroid hormone levels in relation to blood pressure: a population-based study in older men and women

Serum parathormone, vitamin D and cardiovascular risk factors and markers: A pilot study

BACKGROUND AND AIMS

Vitamin D deficiency is a common cause of secondary hyperparathyroidism, particularly in elderly people. The aim of this study was to evaluate the associations of serum vitamin D and parathormone (PTH) concentrations with blood pressure values and hypertension-mediated target organ damage (HMOD), including left ventricular (LV) hypertrophy and carotid plaque (CP).

METHODS AND RESULTS

We enrolled consecutive patients admitted to the Hypertension Center of Federico II University Hospital in Naples, Italy. All patients underwent carotid doppler ultrasound and echocardiography, measurement of vitamin D and PTH levels and main clinical and laboratory parameters. A total of 126 patients (mean age 54 years, 68% males) were enrolled. Pearson's correlation analysis indicated that PTH levels directly correlated with age, diabetes, dyslipidemia, hypertension, fasting glucose, and LV mass, and inversely with glomerular filtration rate, LDL cholesterol, and vitamin D. Vitamin D levels correlated inversely with PTH, diabetes and CP. Multivariate regression models indicated that an increased LV mass was associated with the presence of obesity (β = 0.342; P = 0.001). Maximal intima-media thickness was significantly associated with older age (β = 0.303; P = 0.033). Combined presence of low vitamin D/high PTH levels were associated with more than 4-fold increased risk of having CP in both univariate (OR = 4.77, p = 0.0001) and multivariate regression analysis (OR = 4.52, p = 0.014).

CONCLUSION

In a population at high cardiovascular risk, vitamin D and PTH levels were not directly associated with blood pressure values and HMOD. Secondary hyperparathyroidism due to vitamin D deficiency is associated with carotid atherosclerosis independently of other common cardiovascular risk factors.

Emerging role of vitamin D deficiency as a risk factor for retinal venous occlusions and need for public health measures for its prevention

Purpose

To estimate levels of serum vitamin D in patients of retinal vein occlusion (RVO) and compare with age- and sex-matched controls.

Methods

A prospective case-control study of 54 patients of RVO and 54 age- and sex-matched attendants of patients presenting to a tertiary care hospital in Delhi was performed. Patients on vitamin D supplementations and RVO due to infective or immunological causes or patients of glaucoma were excluded. Serum vitamin D levels of all the study participants along with relevant blood investigations with history and examination were documented. Vitamin D deficiency was defined as <20 ng/ml.

Results

The mean serum vitamin D levels seen in RVO patients and the control group were 14.19 ± 5.23 ng/ml and 19.42 ± 10.27 ng/ml, respectively (P value = 0.001) with an odds ratio of 10.558 (CI = 2.34-47.50), indicating vitamin D deficiency to be strongly correlated with RVO. Maximum patients of RVO (46.3%) were seen during the winter season. The study noted hypertension [odds ratio 20.22 (CI = 5.812-70.347)], dyslipidemia, and anemia [odds ratio 4.107 (CI = 0.62-26.90)] to be the risk factors for RVO as previously proved in the literature. Smoking, diabetes, alcohol intake, and body mass index did not emerge as risk factors for RVO.

Conclusion

Vitamin D deficiency is associated with RVO; hence, estimation of serum vitamin D levels should be advised as a part of routine investigations while looking for the cause of RVOs. Public health measures like food fortification with vitamin D micronutrients and public awareness towards increased sunlight exposure in the community are simple, inexpensive measures that can decrease the burden of sight-threatening disease of RVO in the community.

The relationship between serum 25-hydroxy vitamin D status and hypertension in Syrian population: retrospective cohort study

Introduction

Vitamin D is a liposoluble steroid hormone that plays a crucial role in the maintenance of bone metabolism and calcium homoeostasis. Many studies on the effects of vitamin D on general health have been significantly increased, driven by new findings concerning the systemic and extraskeletal effects of this hormone. This study was performed to determine whether low levels of vitamin D were associated with hypertension in Syrian people.

Materials and methods

This retrospective cohort study consisted of 207 subjects, including 83 (40.1%) patients suffering from essential hypertension and 124 (59.9%) patients with normal blood pressure. Aged older than 18 years, who was referred to the endocrinology clinic from September 2022 to September 2023. The data were analysed by using SPSS (version 25). Logistic regression analyses were performed with adjustments for age, sex, and waist circumference.

Results

Hypertension rates were 73%, 20%, and 5% in 25-hydroxyvitamin D groups less than 12 ng/ml, 12-20 ng/mL, and greater than or equal to 20 ng/ml, respectively. Odds ratios (95% CIs) for hypertension adjusting for age, sex, and waist circumference were 178.6 (30.5_1045.6), 5.13 (0.9_26.5) for 25-hydroxyvitamin D levels less than 12 ng/ml, and 12-20 ng/ml, respectively, compared with the greater than or equal to 20 ng/ml group.

Conclusions

This study has shown a high prevalence of low vitamin D levels (25OHVD/20 ng/ml) among a sample of Syrian people (78.3%). The lowest 25OHVD group was associated with a higher prevalence of hypertension, which refers to an adverse association between vitamin D level and essential hypertension. Further research is needed to confirm this relationship.

Association of serum 25-hydroxyvitamin D concentration with all-cause and cause-specific mortality in hypertensive patients

BACKGROUND AND AIMS

To examine the association of serum 25-hydroxyvitamin D [25(OH)D] with all-cause mortality and disease-specific mortality in patients with hypertension.

METHODS AND RESULTS

This cohort study included US adults in the National Health and Nutrition Examination Survey from 2007 to 2018. All-cause mortality and cause-specific mortality outcomes were determined by association with National Death Index records. Cox proportional risk models were used to estimate hazard ratios (HRs) for all-cause mortality and cause-specific mortality and 95% confidence intervals (CIs) for serum 25(OH)D concentrations. The cohort included 10,325 adult participants. The mean serum 25(OH)D level was 65.87 nmol/L, and 32.2% of patients were vitamin D deficient (<50 nmol/L). During a mean follow-up of 77 months, 1290 deaths were recorded, including 345 cardiovascular deaths and 237 cancer deaths. Patients with higher serum 25(OH)D were more likely to have lower all-cause mortality and cardiovascular mortality than those with serum 25(OH)D < 25.00 nmol/L. For cancer mortality in hypertensive patients, vitamin D may not have a predictive role in this.

CONCLUSIONS

This study shows that higher 25(OH)D levels are significantly associated with lower all-cause mortality and cardiovascular disease (CVD) mortality. These findings suggest that maintaining adequate vitamin D status may reduce the risk of death in patients with hypertension.

Vitamin D and Cardiovascular Diseases: From Physiology to Pathophysiology and Outcomes

Vitamin D is rightly recognized as an essential key factor in the regulation of calcium and phosphate homeostasis, affecting primary adequate bone mineralization. In the last decades, a more complex and wider role of vitamin D has been postulated and demonstrated. Cardiovascular diseases have been found to be strongly related to vitamin D levels, especially to its deficiency. Pre-clinical studies have suggested a direct role of vitamin D in the regulation of several pathophysiological pathways, such as endothelial dysfunction and platelet aggregation; moreover, observational data have confirmed the relationship with different conditions, including coronary artery disease, heart failure, and hypertension. Despite the significant evidence available so far, most clinical trials have failed to prove any positive impact of vitamin D supplements on cardiovascular outcomes. This discrepancy indicates the need for further information and knowledge about vitamin D metabolism and its effect on the cardiovascular system, in order to identify those patients who would benefit from vitamin D supplementation.

Serum vitamin D level alterations in retinal vascular occlusions

AIM

To evaluate serum vitamin D levels in sub-types of retinal vascular occlusions and compare the levels in ischemic and non-ischemic presentations.

METHODS

This study included 50 patients of retinal vascular occlusions comprising central retinal vein occlusion, branch retinal vein occlusion, central retinal artery occlusion, branch retinal artery occlusion (study group) diagnosed on basis of clinical characteristics as well as investigations and an age and gender-matched healthy control group (control group). The study group was further classified into ischemic and non-ischemic subtypes and serum vitamin D levels were analysed and compared.

RESULTS

There were 50 patients of various sub-types of retinal vascular occlusions comprising 13 cases of CRVO, 30 cases of BRVO, 05 cases of CRAO, 02 cases of BRAO and 50 age and sex-matched controls. Mean BCVA and CMT in RVO patients was +1.12 log MAR, 346.72 ± 27.93 µm while in control group was +0.37 log MAR, 236.22 ± 3.71 µm which were statistically significant (p = 0.004; p = 0.002). The mean serum vitamin D value in study group was 18.39 ng/dl as compared to 32.31 ng/dl in control group which was statistically significant (p = 0.001). The difference in the baseline vitamin D value between the ischemic and non -ischemic sub groups among total vascular occlusion was found to be statistically significant (p = 0.010). However, baseline vitamin D levels difference among ischemic and non-ischemic cases in individual sub-types of vascular occlusion was statistically insignificant.

CONCLUSION

High prevalence of low serum vitamin D levels is seen in patients of retinal vascular occlusion spectrum diseases. Moreover, ischemic types of retinal vascular occlusion have significantly lower serum vitamin D levels as compared to non - ischemic despite having fewer no of patients in arterial occlusion sub-types. Therefore, vitamin D supplements may be considered as possible future targeted therapy in optimizing the severity of disease.

Association of parathyroid hormone with risk of hypertension and type 2 diabetes: a dose-response meta-analysis

BACKGROUND

Despite an increase in parathyroid hormone (PTH) has been reported to be associated with a higher risk of hypertension and type 2 diabetes (T2D), the comprehensive evaluation of the dose-response relationship between PTH and hypertension and T2D remains ambiguous. Therefore, a dose-response meta-analysis was performed to quantitatively investigate this association.

METHODS

PubMed, Web of Science, and Embase were systematically searched up to May 2023. Random-effect models were used to estimate the summary odds ratios (ORs) and 95% confidence intervals (CIs). Restricted cubic splines were used to model the dose-response association.

RESULTS

Ten articles (including 13 studies) were identified, with a total of 11,878 cases and 51,234 participants in the meta-analysis. Of these studies, eight (five cohort and three cross-sectional) studies investigated the association of PTH with hypertension; five (two cohort and three cross-sectional) studies assessed the association of PTH with T2D. The results showed a positive relationship between PTH and the risk of hypertension (OR,1.24, 95% CI: 1.16-1.33). We found a linear association between PTH and hypertension (Pnon-linearity= 0.222). In the dose-response analysis, the risk of hypertension increased 5% for every 10 pg/ml increase in PTH (OR,1.05, 95% CI: 1.02-1.08). The pooled OR of T2D risk for a 10 pg/ml increase in PTH was 1.00 (95% CI: 0.98-1.02).

CONCLUSIONS

Elevated PTH is associated with an increased risk of hypertension. However, the evidence of the association between PTH and T2D is limited, and more well-designed studies need to be explored.

Latest Knowledge on the Role of Vitamin D in Hypertension

Hypertension is the third leading cause of the global disease burden, and while populations live longer, adopt more sedentary lifestyles, and become less economically concerned, the prevalence of hypertension is expected to increase. Pathologically elevated blood pressure (BP) is the strongest risk factor for cardiovascular disease (CVD) and related disability, thus making it imperative to treat this disease. Effective standard pharmacological treatments, i.e., diuretics, angiotensin converting enzyme (ACE) inhibitors, angiotensin receptor blocker (ARBs), beta-adrenergic receptor blockers (BARBs), and calcium channel blockers (CCBs), are available. Vitamin D (vitD) is known best for its role in bone and mineral homeostasis. Studies with vitamin D receptor (VDR) knockout mice show an increased renin-angiotensin-aldosterone system (RAAS) activity and increased hypertension, suggesting a key role for vitD as a potential antihypertensive agent. Similar studies in humans displayed ambiguous and mixed results. No direct antihypertensive effect was shown, nor a significant impact on the human RAAS. Interestingly, human studies supplementing vitD with other antihypertensive agents reported more promising results. VitD is considered a safe supplement, proposing its great potential as antihypertensive supplement. The aim of this review is to examine the current knowledge about vitD and its role in the treatment of hypertension.

Bariatric Surgery and Vitamin D: Trends in Older Women and Association with Clinical Features and VDR Gene Polymorphisms

(1) Background: Obesity and its comorbidities can cause burdens and limitations. Bariatric surgery (BS) is indicated as a safe procedure to reduce body mass and improve present comorbidities. However, several complications were reported, such as vitamin D [25(OH)D] deficiency. We evaluated if 25(OH)D serum levels relate to clinical characteristics, symptoms, or habits in women after their BS, and whether the vitamin D receptor (VDR) gene's TaqI and FokI polymorphisms affected 25(OH)D levels and the total body bone mineral density (TBBMD). (2) Methods: This cohort cross-sectional comparative analytical prospective study consisted of 27 women, 61.6 ± 5.0 years, submitted to BS one year prior at a public reference hospital, DF-Brazil. All participants were asked to follow the physical and dietary activity recommendations and received vitamin D3 supplements. Their anthropometric, biochemical, and immunological measurements and blood samples were obtained. (3) Results: 73.3% of participants had low 25(OH)D levels, and their levels correlated positively with TBBMD and negatively with systolic pressure. VDR TaqI did not affect 25(OH)D levels, whereas VDR FokI's allele f presence correlated to a median rise in 25(OH)D levels. Neither polymorphism correlated to TBBMD. (4) Conclusions: 25(OH)D levels were positively correlated with TBBMD, negatively with systolic blood pressure, and were higher in those with the VDR FokI allele f.

Effects of Vitamin D on Cardiovascular Risk and Oxidative Stress

INTRODUCTION

Vitamin D has been primarily studied as an important factor influencing bone and calcium metabolism. Metabolites of vitamin D are essential for whole-body calcium homeostasis, maintaining serum calcium levels within a narrow range by regulating this process in the bones and gut. Nevertheless, its deficiency is also related to increased risk of type 2 diabetes mellitus (T2DM), metabolic syndrome (MS), and cardiovascular disease (CVD)-with increased visceral adipose tissue and body mass index (BMI), as well as the frequently associated hypercholesterolemia. It has been reported that vitamin D levels are inversely related to cardiovascular (CV) risk in men and women. However, the effects of vitamin D on distinct outcomes in women and the dose of supplementation needed to improve clinical endpoints have not been established. 25-Hydroxyvitamin D [25(OH)D] reduces systemic inflammatory mediators in CVD and favors the release of anti-inflammatory cytokines from the immune system. In addition, 25(OH)D can be primarily converted into calcitriol (1,25-dihydroxycholecalciferol [1,25(OH)2D]) in the kidneys through the action of the 1-α-hydroxylase enzyme. Calcitriol, through the downregulation mechanism of renin expression, renin-angiotensin-aldosterone system (RAAS) activity, and its interaction with the vitamin D receptor, can bring CV benefits. The calcitriol form also lowers parathyroid hormone (PTH) levels by indirectly causing a reduction in aldosterone and mineralocorticoid synthesis. Elevated plasma aldosterone is related to endothelial dysfunction and CVD in hypovitaminosis D status.

CONCLUSION

Vitamin D supplementation may benefit certain risk groups, as it improves metabolic variables, reducing oxidative stress and CV outcomes. More studies are needed to define interventions with vitamin D in men and women.

Serum Vitamin D Levels in Relation to Hypertension and Pre-hypertension in Adults: A Systematic Review and Dose–Response Meta-Analysis of Epidemiologic Studies

Background

Findings of observational studies that evaluated the association of serum vitamin D status and high blood pressure were contradictory. This meta-analysis of epidemiologic studies assessed the relation of serum vitamin D levels to hypertension (HTN) and pre-hypertension in adults.

Methods

We conducted a systematic search of all published articles up to March 2021, in four electronic databases (MEDLINE (PubMed), Web of Science (ISI), Embase and Scopus), and Google scholar. Seventy epidemiologic studies (10 prospective cohort, one nested case–control, and 59 cross-sectional investigations) that reported relative risks (RRs), odds ratios (ORs), hazard ratios, or prevalence ratios with 95% CIs for HTN or pre-hypertension in relation to serum vitamin D concentrations in adults were included in the analysis.

Results

In prospective studies, a 16% decrease in risk of hypertension was observed in participants with high levels of serum vitamin D compared to low levels (RR: 0.84; 95%CI: 0.73, 0.96; 12 effect sizes). Dose–response analysis in prospective studies revealed that each 25 nmol/L increase in serum vitamin D concentrations resulted in 5% reduced risk of HTN (RR: 0.95; 95% CI: 0.90, 1.00). Also, a significant nonlinear relationship between serum vitamin D levels and HTN was found (P_nonlinearity < 0.001). In cross-sectional investigations, highest vs. lowest level of serum vitamin D was related to reduced odds of HTN (OR: 0.84; 95%CI: 0.79, 0.90; 66 effect sizes) and pre-hypertension (OR: 0.75; 0.95%CI: 0.68, 0.83; 9 effect sizes). Dose–response analysis in these studies showed that each 25 nmol/L increase in serum vitamin D levels was related to a significant 6% reduction in odds of hypertension in all populations (RR: 0.94; 95%CI: 0.90, 0.99) and 3% in studies with representative populations (RR: 0.97; 95%CI: 0.95, 0.99).

Conclusion

This meta-analysis of epidemiologic studies disclosed that serum vitamin D concentrations were inversely related to the risk of HTN in adults, in a dose–response manner in both prospective cohort and cross-sectional studies.

Systematic Review Registration:http://www.crd.york.ac.uk/Prospero, identifier: CRD42021251513.

The association between vitamin D levels and metabolic syndrome components among metropolitan adolescent population

OBJECTIVES

Vitamin D promotes both lipolysis and lipogenesis, and some pediatric studies showed inconsistent associations between vitamin D and metabolic syndrome (MetS). This cross-sectional study aimed to examine the association between vitamin D levels and MetS components among metropolitan adolescents.

METHODS

A total of 4,149 adolescents aged 10-18 years were recruited from 23 metropolises in China. The MetS conditions were assessed according to the International Diabetes Federation consensus definition, and the serum 25-hydroxy vitamin D (25(OH)D) concentrations were analyzed. The association between MetS components and serum 25(OH)D levels was analyzed by the logistic regression model. Restricted cubic spline was applied to the model nonlinear association.

RESULTS

Prevalence of vitamin D deficiency was 74.9%, and 41.2% of study participants had at least one MetS component. After adjustment, the significant trend for a lower waist-to-height ratio was not observed in study participants with higher serum 25(OH)D quartile (p=0.57), but a significant nonlinear association between abdominal obesity and serum 25(OH)D levels was found (p=0.04): the highest risk of abdominal obesity occurred at 14.1 ng/mL of serum 25(OH)D. The association of serum 25(OH)D was significantly inverse with MetS (OR: 0.95; 95% CI: 0.92-0.98), but not with raised triglycerides (OR: 0.99; 95% CI: 0.96-1.01), raised blood pressure (OR: 0.99; 95% CI: 0.97-1.01) and impaired fasting glycemia (OR: 1.03; 95% CI: 1.01-1.04).

CONCLUSIONS

The net effect of vitamin D on lipid metabolism may be concentration-dependent, and the actual effect of vitamin D on MetS process may be complex among metropolitan adolescents, though serum 25(OH)D is inversely associated with MetS.

The Importance of Correlation between Aldosterone and Parathyroid Hormone in Patients with Primary Hyperparathyroidism

In primary hyperparathyroidism, an increased risk of developing the cardiovascular disease may exist due to increased activity of the renin-angiotensin-aldosterone system. The aim of this study was to evaluate the relationship between parathyroid hormone and aldosterone in patients with primary hyperparathyroidism. The study included 48 patients with primary hyperparathyroidism and 30 healthy subjects who matched age and gender to the study group. This study was conducted at the Center for Laboratory medicine, Clinical center of Vojvodina, Novi Sad, Serbia. In addition to clinical data and laboratory determination of the concentration of total and ionized calcium, phosphorus, measurements of parathyroid hormone, vitamin D, direct renin, and aldosterone were performed by the method of chemiluminescent technology. Compared to the controls, the study group had statistically significantly higher values of aldosterone (p=0.028), total calcium (p=0.01), ionized calcium (p=0.003) and parathyroid hormone (P ≤ 0.001) Serum aldosterone and parathyroid hormone levels were correlated positively in patients with primary hyperparathyroidism (r=0.509, p < 0.05). A statistically significant positive correlation between renin and parathyroid hormone (r=0.688, p < 0.05) and renin and calcium (r=0.673, p < 0.05) was determined in hyperparathyroid patients. In multivariate regression analysis, the strongest predictive variable of aldosterone secretion was parathyroid hormone (p=0.011). An independent relationship between parathyroid hormone and aldosterone in patients with primary hyperparathyroidism and the correlation between renin and parathyroid hormone as well as with calcium indicate not only the direct but also the indirect associations between parathyroid hormone and aldosterone in primary hyperparathyroidism. These findings may represent another possible model of renin-angiotensin-aldosterone-induced organ damage.

Environmental Factors That Affect Parathyroid Hormone and Calcitonin Levels

Calciotropic hormones, parathyroid hormone (PTH) and calcitonin are involved in the regulation of bone mineral metabolism and maintenance of calcium and phosphate homeostasis in the body. Therefore, an understanding of environmental and genetic factors influencing PTH and calcitonin levels is crucial. Genetic factors are estimated to account for 60% of variations in PTH levels, while the genetic background of interindividual calcitonin variations has not yet been studied. In this review, we analyzed the literature discussing the influence of environmental factors (lifestyle factors and pollutants) on PTH and calcitonin levels. Among lifestyle factors, smoking, body mass index (BMI), diet, alcohol, and exercise were analyzed; among pollutants, heavy metals and chemicals were analyzed. Lifestyle factors that showed the clearest association with PTH levels were smoking, BMI, exercise, and micronutrients taken from the diet (vitamin D and calcium). Smoking, vitamin D, and calcium intake led to a decrease in PTH levels, while higher BMI and exercise led to an increase in PTH levels. In terms of pollutants, exposure to cadmium led to a decrease in PTH levels, while exposure to lead increased PTH levels. Several studies have investigated the effect of chemicals on PTH levels in humans. Compared to PTH studies, a smaller number of studies analyzed the influence of environmental factors on calcitonin levels, which gives great variability in results. Only a few studies have analyzed the influence of pollutants on calcitonin levels in humans. The lifestyle factor with the clearest relationship with calcitonin was smoking (smokers had increased calcitonin levels). Given the importance of PTH and calcitonin in maintaining calcium and phosphate homeostasis and bone mineral metabolism, additional studies on the influence of environmental factors that could affect PTH and calcitonin levels are crucial.

Association Between Serum Calcium and the Prevalence of Hypertension Among US Adults

Background: Hypertension is a significant risk factor of cardiovascular diseases, posing a serious threat to global health. Calcium plays an important role in regulating body homeostasis. The association of calcium with hypertension remains uncertain in the general population.

Methods and Results: Cross-sectional data from the 2007–2018 National Health and Nutrition Examination Survey (NHANES) were analyzed. Adjusted multivariable logistic regression analysis and restricted cubic spline were used to investigate the association of serum calcium with the prevalence of hypertension. A total of 26,778 participants were included. The increase in calcium levels showed a positive association with the prevalence of hypertension in all three models with ORs of 1.347 (1.249–1.454), 1.522 (1.401–1.654), and 1.438 (1.306–1.583). The further subgroup analysis demonstrated a robust trend across all categories by sex, age, race, BMI, and eGFR. The restricted cubic spline plot exhibited an S-curve relationship between calcium and hypertension.

Conclusion: Our cross-sectional study demonstrated a positive association between higher serum calcium level and the prevalence of hypertension. Our findings highlighted serum calcium level in hypertensive patients.

Association Between the Circulating Level of 25-Hydroxyvitamin D and Clinical Results After Cardiac Surgery: A Meta-Analysis and Systematic Review

Background: Vitamin D (VitD) is an important pleiotropic hormone for organ systems. Studies have focused on the level of VitD, especially that of 25-hydroxyvitamin D (25-(OH)-VitD), in patients after cardiac surgery and the relationship between VitD deficiency and adverse outcomes, but the results have been inconsistent. We carried out a meta-analysis to evaluate differences in the 25-(OH)-VitD level before and after cardiac surgery, and evaluated the predictive value of 25-(OH)-VitD level in the clinical outcomes of patients undergoing cardiac surgery.

Methods: Studies related to VitD level and cardiac surgery were searched from PubMed, EMBASE, Web of Science, and Cochrane Central Register of Controlled Trials databases from inception to October 2020. We applied the Newcastle–Ottawa Scale to assess the risk of a bias in individual studies. We examined the heterogeneity and publication bias and performed subgroup analyses and sensitivity analyses.

Results: Fifteen studies were included in our analysis. The 25-(OH)-VitD level was significantly lower immediately after surgery [stand mean difference (SMD), 0.69; 95%CI (0.1, 1.28), P = 0.023] and 24-h after surgery [0.84; (0.47, 1.21), 0.000] compared with that before surgery. A higher prevalence of 25-(OH)-VitD deficiency was recorded 24 h after surgery [RR, 0.59; 95%CI (0.47, 0.73), P = 0.00]. Pooled results demonstrated a significant relationship between the preoperative 25-(OH)-VitD level and vasoactive-inotropic score (VIS) [SMD, −3.71; 95%CI (−6.32, −1.10); P = 0.005], and patients with 25-(OH)-VitD deficiency revealed a comparatively poor prognosis and severe condition after cardiac surgery [−0.80; (−1.41, −0.19), 0.01]. However, 25-(OH)-VitD deficiency was not associated with the duration of stay in the intensive care unit.

Conclusions: Cardiac surgery would leads to deficiency of 25-(OH)-VitD. And the preoperative and postoperative levels of 25-(OH)-VitD are associated with adverse events, which is eligible to work as an indicator to demonstrate clinical outcomes.

Combined associations of 25-hydroxivitamin D and parathyroid hormone with diabetes risk and associated comorbidities among U.S. white and black women

Background/objectives

There is evidence of black–white differences in vitamin D status and cardiometabolic health. This study aimed to further evaluate the joint associations of 25-hydroxyvitamin D [25(OH)D] and parathyroid hormone (PTH) with risks of diabetes and related cardiometabolic comorbidities among white and black women.

Subjects/methods

We cross-sectionally and prospectively analyzed data from 1850 black and 3000 white postmenopausal women without cardiovascular disease or dialysis at baseline from the Women’s Health Initiative—Observational Study. Weighted Cox proportional hazards analyses and weighted logistic regression models were used to examine the joint associations of 25(OH)D and PTH with incident diabetes and prevalence of other diabetes-related cardiometabolic comorbidities (including CKD, hypertension, or obesity).

Results

We identified 3322 cases of obesity (n = 1629), hypertension (n = 2759), or CKD (n = 318) at baseline and 453 incident cases of diabetes during 11 years of follow-up. Cross-sectionally, lower 25(OH)D and higher PTH were independently associated with higher prevalence of hypertension [odds ratio (OR) = 0.79; 95% confidence interval (CI): 0.72–0.87 and OR = 1.55; 95% CI: 1.39–1.73] among white women only. When stratified by diabetes status, compared to women with 25(OH)D ≥50 nmol/L and PTH ≤6.89 pmol/L (65 pg/mL), women who did not have diabetes with vitamin D deficiency (<50 nmol/L) and PTH excess (>6.89 pmol/L) had higher prevalence of CKD, hypertension, or obesity (OR = 4.23; 95% CI: 2.90–6.18) than women who had diabetes (OR = 1.89; 95% CI: 0.96–3.71). Prospectively, lower 25(OH)D was associated with lower diabetes incidence [hazard ratio (HR) = 0.73; 95% CI: 0.62–0.86] in white women. Jointly, compared to the group with 25(OH)D ≥50 nmol/L and PTH ≤6.89 pmol/L, white women with 25(OH)D deficiency (<50 nmol/L) had elevated risk for diabetes, regardless of PTH levels.

Conclusions

Low 25(OH)D and high PTH were jointly associated with increased risk of diabetes among white women only. Their joint associations with high prevalence of CKD, hypertension, and obesity were more pronounced among women without diabetes.

Relationship between intact parathyroid hormone and all-cause death, cardiovascular events, and ectopic calcification in patients with diabetic kidney disease: A retrospective study

AIM

We aimed to investigate the relationship between intact parathyroid hormone (iPTH) levels and all-cause death, cardiovascular events, and ectopic calcification in patients with diabetic kidney disease (DKD).

METHODS

In this retrospective cohort study, we collected the clinical data of 508 patients with clinically diagnosed DKD. The primary and secondary outcomes were all-cause death or cardiovascular events and ectopic calcification, respectively. We used different regression methods to analyze the relationship between various clinical parameters and the two clinical outcomes.

RESULTS

We found that iPTH was a risk factor for all-cause death and cardiovascular events (hazards ration [HR]: 2.817, 95% confidence interval [CI]: 1.045-6.562, P = 0.016). Meanwhile, diabetes duration (HR: 1.090, 95% CI: 1.045-1.138, P < 0.0001), triglycerides (TG) (HR: 1.254, 95% CI: 1.049-1.499, P = 0.013), and iPTH (HR: 1.954, 95% CI: 1.001-3.813, P = 0.049) were independent risk factors for ectopic calcification. In contrast to patients with lower iPTH levels (iPTH < 31.7 pg/mL), patients with higher iPTH levels (iPTH ≥ 31.7 pg/mL) had increased ectopic calcification rate (P = 0.002) and decreased survival time (P < 0.001).

CONCLUSION

In patients with DKD, higher iPTH levels were significantly related to worsen clinical outcomes.

Vitamin D and Vascular Disease

Cardiovascular disease (CVD) is a major cause of morbidity and mortality worldwide. Vitamin D deficiency has been identified as a potential risk factor for a number of diseases unrelated to the classical skeletal pathophysiology, such as cancer and CVD, but the effects of vitamin D supplementation are less clear. Purpose of this narrative review is to discuss the evidence suggesting an association between vitamin D status and CVD as well as the results of supplementation studies. Vitamin D deficiency has been associated with CVD risk factors such as hypertension, dyslipidemia and diabetes mellitus as well as with cardiovascular events such as myocardial infarction, stroke and heart failure. While vitamin D deficiency might contribute to the development of CVD through its association with risk factors, direct effects of vitamin D on the cardiovascular system may also be involved. Vitamin D receptors are expressed in a variety of tissues, including cardiomyocytes, vascular smooth muscle cells and endothelial cells. Moreover, vitamin D has been shown to affect inflammation, cell proliferation and differentiation. While observational studies support an association between low plasma vitamin D levels and increased risk of CVD, Mendelian randomization studies do not support a causal association between the two. At present, high quality randomized trials do not find evidence of significant effects on CVD endpoints and do not support supplementation of vitamin D to decrease CVD events.

Vitamin D Deficiency and Risk of Metabolic Syndrome in Aging Men

The elderly population is rapidly increasing; hence, the disability due to age-related diseases has become an important socioeconomic burden. Amongst age-related diseases cardiovascular ones (CVD) have a huge impact on morbidity and mortality and are associated with metabolic syndrome (MetS). Several studies investigated the role of hypovitaminosis D in the pathogenesis of MetS and of CVD, this review unravels the relationship between aging/senescence, vitamin D, gender, and pathogenesis of MetS.

Serum vitamin D status and metabolic syndrome: a systematic review and dose-response meta-analysis

BACKGROUD/OBJECTIVES

Evidence has suggested an association between serum vitamin D and metabolic syndrome (MetS), but prospective studies are very limited. The objective was to assess the dose-response association between serum vitamin D concentration and MetS risk using a systematic review and meta-analysis of updated observational studies.

MATERIALS/METHODS

Using MEDLINE, PubMed, and Embase, a systematic literature search was conducted through February 2020 and the references of relevant articles were reviewed. A random-effects model was used to estimate the summary odds ratio/relative risk and 95% confidence interval (CI). Heterogeneity among studies was evaluated with I² statistic. In total, 23 observational studies (19 cross-sectional studies, and four cohort studies) were included in the meta-analysis.

RESULTS

The pooled estimates (95% CI) for MetS per 25-nmol/L increment in serum vitamin D concentration were 0.80 (95% CI, 0.76–0.84; I² = 53.5) in cross-sectional studies, and 0.85 (95% CI, 0.72–0.98; I² = 85.8) in cohort studies. Similar results were observed, irrespectively of age of study population, study location, MetS criteria, and adjustment factors. There was no publication bias for the dose-response meta-analysis of serum vitamin D concentrations and MetS.

CONCLUSIONS

Dose-response meta-analysis demonstrated that a 25-nmol/L increment in the serum vitamin D concentration was associated with 20% and 15% lower risks of MetS in cross-sectional studies and cohort studies, respectively.

Serum Parathyroid Hormone Predicts Mortality in Coronary Angiography Patients with Type 2 Diabetes

BACKGROUND

Elevated serum levels of parathyroid hormone (PTH), one of the main regulators of calcium homeostasis and vitamin D metabolism, have been proposed as predictors of mortality. The impact of type 2 diabetes mellitus (T2DM) on the putative association between PTH and mortality has not been investigated thus far.

AIM

The aim of our study was to investigate the impact of T2DM on the power of PTH to predict mortality risk.

METHODS

Serum PTH levels were determined in 904 consecutive Caucasian patients referred to coronary angiography for the evaluation of established or suspected stable coronary artery disease (CAD), including 235 patients with T2DM. Prospectively, deaths were recorded over a mean follow-up period of 6.3 years.

RESULTS

PTH at baseline did not differ significantly between patients with and without T2DM (P = .307). Cox regression analysis revealed that the serum PTH level strongly predicted all-cause mortality in patients with T2DM (hazard ratio [HR] = 2.35 [1.37-4.03]; P = .002), whereas PTH did not predict all-cause mortality in patients without T2DM (HR = 1.04 [0.81-1.32]; P = .766). The interaction term PTH × T2DM was significant (P = .006), indicating a significantly stronger impact of PTH on mortality risk in patients with T2DM than in individuals without diabetes. The impact of PTH on mortality risk in patients with T2DM remained significant after adjustment for glycated hemoglobin A1c, diabetes duration, classical cardiovascular risk factors, serum levels of vitamin D, and kidney function (HR = 2.10 [1.10-4.10]; P = .030).

CONCLUSION

We conclude that PTH is a significantly stronger predictor of all-cause mortality in patients with T2DM than in those without T2DM.

Vitamin D and Cardiovascular Disease, with Emphasis on Hypertension, Atherosclerosis, and Heart Failure

Vitamin D deficiency is the most common nutritional deficiency, affecting almost one billion people worldwide. Vitamin D is mostly known for its role in intestinal calcium absorption and bone mineralization. However, the observation of seasonal changes in blood pressure and the subsequent identification of vitamin D receptor (VDR) and 1α-hydroxylase in cardiomyocytes, as well as endothelial and vascular smooth muscle cells, implicated a role of vitamin D in the cardiovascular system. Animal studies provided compelling evidence that vitamin D signaling is essential for cardiovascular integrity, especially for the regulation of vascular tone and as an antifibrotic and antihypertrophic signaling pathway in the heart. In addition, observational studies reported an association between vitamin D deficiency and risk of hypertension, atherosclerosis, and heart failure. However, recent clinical intervention studies failed to prove the causal relationship between vitamin D supplementation and beneficial effects on cardiovascular health. In this review, we aim to highlight our current understanding of the role of vitamin D in the cardiovascular system and to find potential explanations for the large discrepancies between the outcome of experimental studies and clinical intervention trials.

Vitamin D Receptor Gene Polymorphisms and the Risk of Metabolic Syndrome (MetS): A Meta-Analysis

BACKGROUND

Several studies have assessed the association between the vitamin D receptor (VDR) polymorphism and the risk of metabolic syndrome (MetS). However, the results were inconsistent and inconclusive. Therefore, we conducted a meta-analysis to clarify the exact association between the vitamin D receptor (VDR) polymorphisms and the risk of MetS.

METHODS

All accessible studies reporting the association between the FokI (rs2228570) or/and TaqI (rs731236) or/and BsmI (rs1544410) or/and ApaI (rs7975232 polymorphisms of the Vitamin D Receptor and susceptibility to MetS published prior to February 2019 were systematically searched in Web of Science, Scopus, and PubMed. After that, Odds ratios (ORs) and their corresponding 95% confidence intervals (CIs) were estimated to evaluate the strength of the association in five genetic models.

RESULTS

A total of 9 articles based on four gene variations, and comprising 3348 participants with 1779 metabolic syndrome patients were included. The overall results suggested a significant association between BsmI (rs1544410) polymorphism and MetS susceptibility in recessive model (OR, 0.72, 95% CI, 0.55-0.95, fixed effect model), allelic model (OR, 0.83, 95% CI, 0.72-0.95, fixed effect model), and bb vs BB (OR, 0.65, 95% CI, 0.46-0.93, fixed effect). However, no significant association was identified between TaqI (rs731236) polymorphism, ApaI (rs7975232) polymorphism, and FokI (rs2228570) polymorphism and MetS.

CONCLUSION

This meta-analysis suggested an association between the BsmI (rs1544410) polymorphism and MetS. Indeed, BsmI (rs1544410) acts as a protective factor in the MetS. As a result, the VDR gene could be regarded as a promising pharmacological and physiological target in the prevention or treatment of the MetS.

Association of Serum Levels of Vitamin D with Blood Pressure Status in Northern Iranian Population: The PERSIAN Guilan Cohort Study (PGCS)

Background

Evidence in the last decades has indicated an association between vitamin D and cardiovascular risk factors including blood pressure. The present study aimed to determine whether serum 25-hydroxyvitamin D is independently associated with blood pressure in a large population-based study.

Methods

The study was based on subjects from PERSIAN Guilan Cohort Study (PGCS), a prospective, population-based cohort study in Guilan, Iran. In 9520 men and women, aged 35-70 years, serum 25-hydroxyvitamin D, systolic and diastolic blood pressure were measured. Multiple logistic and linear regression analyses were conducted with adjustments for demographic factors (age and gender), anthropometric characteristics (waist circumference and body mass index), lifestyle variables (physical activity, alcohol, and smoking consumption), and renal function (serum creatinine).

Results

Fully adjusted linear regression analyses revealed a weak but statistically significant negative association between serum 25-hydroxyvitamin D levels and systolic blood pressure (β = -0.02, 95% CI= -0.052 to -0.0001, P-value=0.04), whereas vitamin D status was not significantly associated with diastolic blood pressure (β = -0.01, 95% CI= -0.026 to 0.009, P-value=0.3). Serum 25-hydroxyvitamin D status showed no significant association with the presence of hypertension (OR 1.09, 95% CI=0.94 to 1.25 for the lowest (25OHD <12 ng/mL) versus the highest (25OHD ≥20 ng/mL) category).

Conclusion

Lower serum vitamin 25 (OH) D levels were associated with higher systolic blood pressure; however, it was not associated with diastolic blood pressure and presence of hypertension.

Association between Serum Calcium and Risk of Cardiometabolic Disease among Community-dwelling Adults in Taiwan

Serum calcium, although only comprising 1% of total body calcium, is involved in intracellular signal pathways, vascular dilatation/constriction, and muscle contraction, which are crucial for insulin secretion, cholesterol catabolism, and blood pressure regulation. As far as we know, research on the relationship between serum calcium level and metabolic syndrome (MetS), diabetes, and hypertension in one longitudinal study is rare. Owing to the crucial role of serum calcium in human cardiometabolic physiology and lack of related study so far, this study aims to describe the relationship between serum calcium level and the incidence of MetS, diabetes, and hypertension. During the period 2010-2016, there are two parts to our study: cross-sectional analysis and longitudinal analysis. Logistic regression was applied for cross-sectional analysis of the association between serum calcium level or albumin-corrected calcium (ACCA) and the prevalence of MetS, diabetes, or hypertension. Receiver operating characteristic (ROC) curve analysis was used for calculating of optimal cut-off value of serum calcium and ACCA. Cox proportional regression for development of MetS, diabetes, and hypertension according to different cut-off values of serum calcium level and ACCA were conducted. At baseline, there were 27,364 participants in our study. Serum calcium level had positive association with diabetes in the total population, male, and female. ACCA level had positive association with diabetes in the total population, male, and female. In unadjusted and multivariate Cox proportional hazard models, serum calcium level was associated with increased risk of incident MetS in the total population and male. ACCA was associated with increased risk of incident MetS in the total population and male. ACCA was associated with increased risk of incident diabetes in the total population and male participants. This study describes the relationship between serum calcium level and the incidence of MetS, diabetes, and hypertension. Higher serum calcium level is associated with increased risk of MetS, diabetes, and hypertension.

Association of Vitamin D Levels With Kidney Volume in Autosomal Dominant Polycystic Kidney Disease (ADPKD)

Vitamin D possesses renoprotective effects beyond mineral metabolism, potentially reducing arterial blood pressure and inflammation and vitamin D enzymes (CYP24A1 and CYP27B1) as well as vitamin D receptor (VDR) contribute to its homeostasis. In the present study, we aimed to determine vitamin D association with kidney volume, blood pressure parameters and inflammatory markers in ADPKD. This cross-sectional study, conducted from August 2011 through May 2016, evaluated 25(OH)D, 1,25(OH)2D and other hormonal/biochemical serum and urinary parameters, inflammatory markers and monocyte expression of VDR, CYP24A1, CYP27B1 in 74 ADPKD patients. The height-adjusted total kidney volume (htTKV) was determined by MRI and blood pressure (BP) measured through 24-h ambulatory BP monitoring (ABPM).Vitamin D insufficiency was present in 62% of patients and CYP24A1 was overexpressed in this group, raising a hypothesis of 25(OH)D increased catabolism. Serum 25(OH)D levels and VDR expression were negatively correlated with htTKV as was VDR with IL-6, IL-10, CRP, and NFκB. A multiple linear regression analysis with htTKV as dependent variable, including hypertension, CRP, eGFR, age, time since diagnosis, VDR, and 25(OH)D adjusted for season of the year showed that only the first three parameters were independent predictors of the former. There has been no association of serum 25(OH)D and VDR expression with ABPM parameters. Present findings suggested that low levels of serum 25(OH)D and VDR expression are associated with a higher kidney volume in ADPKD patients, but do not represent independent risk factors for htTKV.

Mechanisms Involved in the Relationship between Low Calcium Intake and High Blood Pressure

There is increasing epidemiologic and animal evidence that a low calcium diet increases blood pressure. The aim of this review is to compile the information on the link between low calcium intake and blood pressure. Calcium intake may regulate blood pressure by modifying intracellular calcium in vascular smooth muscle cells and by varying vascular volume through the renin-angiotensin-aldosterone system. Low calcium intake produces a rise of parathyroid gland activity. The parathyroid hormone increases intracellular calcium in vascular smooth muscles resulting in vasoconstriction. Parathyroidectomized animals did not show an increase in blood pressure when fed a low calcium diet as did sham-operated animals. Low calcium intake also increases the synthesis of calcitriol in a direct manner or mediated by parathyroid hormone (PTH). Calcitriol increases intracellular calcium in vascular smooth muscle cells. Both low calcium intake and PTH may stimulate renin release and consequently angiotensin II and aldosterone synthesis. We are willing with this review to promote discussions and contributions to achieve a better understanding of these mechanisms, and if required, the design of future studies.

Sex-specific role of CYP24A1 rs2762939 in the risk of essential hypertension based on the serum vitamin D and total renin concentrations

CYP24A1, Vitamin D 24-hydroxylase catabolizes 25-hydroxyvitamin D (25(OH)D) and 1,25-dihydroxyvitamin D to 24-hydroxylated vitamin D products. It is widely known that low Vitamin D can lead to increased renal renin and angiotensin II production, consequently elevating blood pressure or development of essential hypertension (EH). We have conducted an investigation on hypertensives and controls to evaluate the association of the gene variant, CYP24A1 rs2762939 and 25(OH)D in an Indian population with EH. On gender-based stratification, with multivariate logistic analysis after adjustment for covariates, the CYP24A1 rs2762939 CC variant showed a higher risk of EH in males (aOR = 3.141, CI 1.164-8.478, P = .024) while females illustrated an inverse association with EH (aOR = 0.398, CI 0.172-0.092, P = .031). The 25(OH)D levels among the three genotypes of hypertensives substantiate these results. Our results clearly suggest that gender, CYP24A1 rs2762939, and Vitamin D status may play a significant role in disease susceptibility towards EH in Indian population.

Parathyroidectomy improves cardiovascular risk factors in normocalcemic and hypercalcemic primary hyperparathyroidism

BACKGROUND

Parathyroidectomy has ameliorated cardiovascular risk factors in patients with hypercalcemic primary hyperparathyroidism (PHPT), but the effect of parathyroidectomy on normocalcemic PHPT is not exactly known. This case-controlled study aimed to investigate the effect of parathyroidectomy on cardiovascular risk factors in patients with normocalcemic and hypercalcemic PHPT.

METHODS

Subjects with normocalcemic PHPT (n = 35), age- and sex-matched hypercalcemic PHPT (n = 60) and age- and sex-matched control (n = 60) were included. Cardiometabolic disorders were investigated with traditional cardiometabolic risk factors and the Framingham cardiovascular risk score (CRS) before and 6 months after parathyroidectomy.

RESULTS

Diabetes, dyslipidemia, hypertension, obesity, insulin resistance, osteoporosis, having fractures were similarly increased in the hypercalcemic and normocalcemic PHPT groups (p > 0.05) compared with the controls (p < 0.05). Blood pressures, glucose metabolism (glucose, insulin, HOMA-IR) and lipid profiles were similarly increased in the PHPT groups (p > 0.05) compared with the controls (p < 0.05). After parathyroidectomy, blood pressures, serum total cholesterol, and HOMA-IR were decreased in both PHPT groups (p < 0.05). CRS was lower in the controls (5.74 ± 3.24, p < 0.05). After parathyroidectomy, CRS was decreased in the normocalcemic (11.98 ± 10.11 vs. 7.37 ± 4.48) and hypercalcemic (14.62 ± 11.06 vs. 8.05 ± 7.72) PHPT groups. Increased blood pressures were independent predictors of serum iPTH.

CONCLUSION

The normocalcemic and hypercalcemic PHPT groups had similarly increased cardiovascular risk factors, even independently of serum calcium. Parathyroidectomy ameliorated the increased cardiovascular risk factors in both normocalcemic and hypercalcemic PHPT.

Dietary Intake of Vitamin D and Its Relation with Blood Pressure in the Elderly Population

Background

Population studies have demonstrated that there is an inverse association between dietary intake of vitamin D and the mean blood pressure in elderly in particular. So, we investigated the correlation between vitamin D intake and the mean blood pressure in the elderly with and without nursing care.

Methods

Based on a cross-sectional design, this study was conducted on 152 old people with and without nursing care. Assessment of the dietary intake of nutrients was done by an expert dietitian using food frequency questionnaire and nutritionist IV software analyzer. Also, the mean blood pressure was extracted from participants' files. The independent samplet-test, Chi-square test, and partial correlation test were used for data analysis.

Results

Mean ± SD age, weight, height, body mass index (BMI) of participants, and the percentage of male/females were 68.7 ± 5.5 years, 63.5 ± 7.9 kg, 162.5 ± 7.1 cm, 24.1 ± 3.4 kg/m² and 48.7/51.3, respectively. Also, a significant negative relationship was observed between vitamin D intake and systolic blood pressure in all participants (P value = 0.028, r = -0.179). There was no significant correlation between vitamin D intake and diastolic blood pressure (P value = 0.558, r = -0.048).

Conclusions

The findings revealed that the nursing care can improve dietary intake of vitamin D in the elderly population. Also, a negative correlation was found between vitamin D intake and systolic blood pressure among all the elderly.

Cardiovascular findings in patients with nonsurgical hypoparathyroidism and pseudohypoparathyroidism: A cohort study

OBJECTIVE

As only sparse data are available on indices of cardiovascular health among patients with nonsurgical hypoparathyroidism (Ns-HypoPT) and pseudohypoparathyroidism (PHP), we aimed to compare the cardiovascular profile between these groups of patients.

METHODS

A total of 56 patients with Ns-HypoPT and 30 with PHP were included and underwent a clinical examination including blood sampling and measurements of arterial stiffness, pulse wave velocity (PWV) and blood pressure (BP). Arterial stiffness and PWV were measured using AtCor SphygmoCor-XCEL (Atcor Medical Pty Ltd, Sydney, NSW, Australia).

RESULTS

Patients with Ns-HypoPT had an average age of 47 ± 17 years (68% females) and PHP patients 36 ± 13 years (80% females). Over 70% in both groups were genetically screened. Groups did not differ in terms of a history of cardiovascular disease, smoking status, use of calcium and vitamin D supplements or treatment with cholesterol-lowering or antihypertensive drugs. Compared with Ns-HypoPT, PHP patients had significantly lower levels of high-density lipoproteins (HDL) cholesterol and average glucose from HbA1c (P_both  = 0.01). PWV was significantly higher among patients with Ns-HypoPT (P_crude  = 0.02), even after adjustment for mean arterial pressure, body mass index, age and gender (P_adjusted  < 0.01). Heart rate was significantly higher in Ns-HypoPT compared with PHP (P = 0.03). Office BP and 24-hour ambulatory BP did not differ between groups (P > 0.05).

CONCLUSION

Patients with Ns-HypoPT have compared with PHP a higher arterial stiffness and heart rate. This has been associated with an increased risk of cardiovascular disease. Our data suggest that resistance to PTH is present in the cardiovascular system in PHP.

Association of circulating 25-hydroxyvitamin D and parathyroid hormone with carotid intima media thickness in children and adolescents with excess weight

Evidence on the association of vitamin D and parathyroid hormone (PTH) with cardiovascular risk factors in the young is limited. We therefore assessed the relationships of circulating vitamin D and PTH concentrations and subclinical atherosclerosis in overweight or obese children and adolescents. This was a cross-sectional study, investigated the association of 25-hydroxyvitamin D (25(OH)D), intact PTH (iPTH), and iPTH/25(OH)D ratio with carotid intima-media thickness (cIMT) in 368 Iranian children and adolescents with a body mass index (BMI) ≥1 z-score based on WHO criteria. Ultrasound measurement of cIMT was performed. Multivariable linear and logistic regressions were used to test associations between 25(OH)D, iPTH, and iPTH/25(OH)D ratio using one-ln-unit increment with cIMT. Median (25-75 interquartile range) 25(OH)D and iPTH concentrations were 11.8 (8.2-18.6) ng/ml and 38.2 (25.0-61.4) pg/ml, respectively. Among boys, each one-ln-unit increase of iPTH and iPTH/25(OH)D ratio was significantly associated with 0.194 mm and 0.147 mm increase, respectively, in cIMT, after adjustment for confounders. A similar pattern of association was observed between iPTH (β = 0.143, p = 0.037) and iPTH/25(OH)D ratio (β=0.172, p = 0.007) with cIMT among obese participants. Furthermore, among obese participants in the fully adjusted model, each one-ln-unit increase of iPTH and 25(OH)D/iPTH ratio was significantly associated with 53% and 39% increased odds of having high cIMT, respectively. Girls and those who were overweight did not show any significant association of 25(OH)D, iPTH, and iPTH/25(OH)D ratio with cIMT. High iPTH and iPTH/25(OH)D ratio were associated with increased cIMT in boys and those who are obese.

Vitamin D Deficiency is not Associated with Higher Levels of SYNTAX Score

Objective

To evaluate the association between serum vitamin D (vitD) level and SYNTAX (synergy between percutaneous coronary intervention with taxus and cardiac surgery) score (SS).

Methods

The medical records of consecutive patients, who underwent coronary artery bypass graft surgery, were retrospectively reviewed. The study group consisted of 158 patients. Biochemical, clinical, and echocardiographic parameters and SS were evaluated in all patients. The patients were divided into 2 groups according to SS (≥23= high, <23= low).

Results

The high SYNTAX score (HSS) group was older and had higher body mass index, C-reactive protein (CRP), low-density lipoprotein, and fasting plasma glucose level than the low SYNTAX score (LSS) group. The HSS group had lower high-density lipoprotein and vitD level than the LSS group. The HSS group had a higher prevalence of diabetes mellitus (DM), hypertension (HT), hyperlipidemia (HL), and current smoking patients than the LSS group. On univariate analysis, age, HT, DM, HL, smoking, CRP, and serum vitD level were associated with HSS. On multivariate analysis, HT, DM, and HL were independent predictors of HSS (odds ratio [OR]: 2.137, 95% confidence interval [CI]: 1.468-2.935, P<0.001; OR: 3.559, 95% CI: 2.763-5.927, P<0.001; OR: 2.631, 95% CI: 1.529-3.438, P<0.001; respectively).

Conclusion

In our study, we have found out that HT, DM, and HL were independent predictors of HSS. Serum vitD level was not found to be an independent predictor of HSS.

Comprehensive Review on Diabetes Associated Cardiovascular Complications - The Vitamin D Perspective

Vitamin D, a steroid hormone is primarily known for its role in calcium and bone mineral homeostasis. Over the years, vitamin D has been implicated in various non-skeletal diseases. The extraskeletal phenomenon can be attributed to the presence of vitamin D receptors (VDRs) in almost all cells and identification of 1-α hydroxylase in extrarenal tissues. The vitamin D deficiency (VDD) pandemic was globally reported with increasing evidence and paralleled the prevalence of diabetes, obesity and cardiovascular diseases (CVDs). A dependent link was proposed between hypovitaminosis D glycemic status, insulin resistance and also the other major factors associated with type 2 diabetes leading to CVDs. Insulin resistance plays a central role in both type 2 diabetes and insulin resistance syndrome. These 2 disorders are associated with distinct etiologies including hypertension, atherogenic dyslipidemia, and significant vascular abnormalities that could lead to endothelial dysfunction. Evidence from randomised clinical trials and meta-analysis, however, yielded conflicting results. This review summarizes the role of vitamin D in the regulation of glucose homeostasis with an emphasis on insulin resistance, blood pressure, dyslipidaemia, endothelial dysfunction and related cardiovascular diseases and also underline the plausible mechanisms for all the documented effects.

Exploring the concept of functional vitamin D deficiency in pregnancy: impact of the interaction between 25-hydroxyvitamin D and parathyroid hormone on perinatal outcomes

Background

Associations of vitamin D with perinatal outcomes are inconsistent and few studies have considered the wider calcium metabolic system.

Objectives

We aimed to explore functional vitamin D deficiency in pregnancy by investigating associations between vitamin D status, parathyroid hormone (PTH), and perinatal outcomes.

Design

SCOPE (Screening for Pregnancy Endpoints) Ireland is a prospective cohort study of low-risk, nulliparous pregnant women. We measured serum 25-hydroxyvitamin D [25(OH)D] and PTH at 15 wk of gestation in 1754 participants.

Results

Mean ± SD 25(OH)D was 56.6 ± 25.8 nmol/L (22.7 ± 10.3 ng/mL) and geometric mean (95% CI) PTH was 7.84 pg/mL (7.7, 8.0 pg/mL) [0.86 pmol/L (0.85, 0.88 pmol/L)]. PTH was elevated in 34.3% of women who had 25(OH)D <30 nmol/L and in 13.9% of those with 25(OH)D ≥75 nmol/L. Whereas 17% had 25(OH)D <30 nmol/L, 5.5% had functional vitamin D deficiency, defined as 25(OH)D <30 nmol/L with elevated PTH. Elevated mean arterial pressure (MAP), gestational hypertension, pre-eclampsia, and small-for-gestational-age (SGA) birth were confirmed in 9.2%, 11.9%, 3.8%, and 10.6% of participants, respectively. In fully adjusted regression models, neither low 25(OH)D nor elevated PTH alone increased the risk of any individual outcome. The prevalence of elevated MAP (19.1% compared with 9.7%) and SGA (16.0% compared with 6.7%) were highest (P < 0.05) in those with functional vitamin D deficiency compared with the reference group [25(OH)D ≥75 nmol/L and normal PTH]. The adjusted prevalence ratio (PR) and RR (95% CIs) for elevated MAP and SGA were 1.83 (1.02, 3.27) and 1.53 (0.80, 2.93), respectively. There was no effect of functional vitamin D deficiency on the risk of gestational hypertension (adjusted RR: 1.00; 95% CI: 0.60, 1.67) or pre-eclampsia (adjusted RR: 1.17; 95% CI: 0.32, 4.20).

Conclusion

The concept of functional vitamin D deficiency, reflecting calcium metabolic stress, should be considered in studies of vitamin D in pregnancy. The SCOPE pregnancy cohort is registered at http://www.anzctr.org.au as ACTRN12607000551493.

Lack of vitamin D signalling per se does not aggravate cardiac functional impairment induced by myocardial infarction in mice

Epidemiological studies have linked vitamin D deficiency to an increased incidence of myocardial infarction and support a role for vitamin D signalling in the pathophysiology of myocardial infarction. Vitamin D deficiency results in the development of secondary hyperparathyroidism, however, the role of secondary hyperparathyroidism in the pathophysiology of myocardial infarction is not known. Here, we aimed to explore further the secondary hyperparathyroidism independent role of vitamin D signalling in the pathophysiology of myocardial infarction by inducing experimental myocardial infarction in 3-month-old, male, wild-type mice and in mice lacking a functioning vitamin D receptor. In order to prevent secondary hyperparathyroidism in vitamin D receptor mutant mice, all mice were maintained on a rescue diet enriched with calcium, phosphorus, and lactose. Surprisingly, survival rate, cardiac function as measured by echocardiography and intra-cardiac catheterisation and cardiomyocyte size were indistinguishable between normocalcaemic vitamin D receptor mutant mice and wild-type controls, 2 and 8 weeks post-myocardial infarction. In addition, the myocardial infarction-induced inflammatory response was similar in vitamin D receptor mutants and wild-type mice, as evidenced by a comparable upregulation in cardiac interleukin-1-β and tumor-necrosis-factor-α mRNA abundance and similar elevations in circulating interleukin-1-β and tumor-necrosis-factor-α. Our data suggest that the lack of vitamin D signalling in normocalcaemic vitamin D receptor mutants has no major detrimental effect on cardiac function and outcome post-myocardial infarction. Our study may have important clinical implications because it suggests that the secondary hyperparathyroidism induced by vitamin D deficiency, rather than the lack of vitamin D signalling per se, may negatively impact cardiac function post-myocardial infarction.

Vitamin D Deficiency and Supplementation in Cardiovascular Disorders

Cardiovascular disease (CVD) is the leading cause of death in developed countries. Similarly, the frequency of vitamin D deficiency is increasing, and a number of epidemiologic and clinical studies have suggested that there is an increased risk of CVD among people with depletion of this vitamin. This has raised much interest in the potential pathogenic and therapeutic role of vitamin D in CVD. However, randomized trials and meta-analyses have not shown a clear benefit of vitamin D supplementation with respect to cardiovascular events. Herein, we provide a comprehensive review of the most relevant evidence to date regarding vitamin D deficiency and supplementation, and their respective impact on CVD prevention and treatment.

Parathyroid hormone: Data mining for age-related reference intervals in adults

OBJECTIVE

Age-related changes in parathyroid hormone (PTH) have been previously documented in adults. However, because of the limitations of traditional approaches to establishing reference intervals, age-related reference intervals have not been defined. We sought to use a data mining approach to derive age-related PTH reference intervals.

DESIGN AND PARTICIPANTS

Results from patients undergoing PTH testing over a 4-year period were extracted from the database of a private pathology laboratory in New South Wales, Australia. Patients were included in the study if they were 18 years or older and had simultaneous determination of PTH, serum calcium, estimated glomerular filtration rate and 25-hydroxyvitamin D (25-OHD). Patients with abnormalities of serum calcium or renal function were excluded.

MEASUREMENTS

Bhattacharya analysis of log-transformed data was used to derive age-related PTH reference intervals across adulthood.

RESULTS

Results were available for 33 652 subjects. Among patients with optimal 25-OHD status, older age was associated with higher PTH concentrations. Age-related reference intervals were derived and showed a 63% increase in the upper and lower reference limits between the youngest (18-29 years of age) and the oldest (80 years of age or older) age partitions. The appropriateness of using a single reference interval for patients of all ages was evaluated against objective criteria and was found to be unsatisfactory.

CONCLUSIONS

Data mining was demonstrated to be a useful tool for establishing age-related PTH reference intervals. The technique demonstrated that increasing age is associated with higher PTH concentrations and that age-related reference intervals are important for accurate result interpretation.

Vitamin D and cardiovascular diseases: Causality

Vitamin D regulates blood pressure, cardiac functions, and endothelial and smooth muscle cell functions, thus, playing an important role in cardiovascular health. Observational studies report associations between vitamin D deficiency with hypertension and cardiovascular-related deaths. Peer-reviewed papers were examined in several research databases as per the guidelines of the Preferred Reporting Items for Systematic Reviews, using key words that address the relationship between vitamin D and cardiovascular disease. Correlations and interpretations were made considering the risks-benefits, broader evidence, and implications. This review analyzed current knowledge regarding the effects of vitamin D on the cardiovascular system. 1,25(OH)₂D and related epigenetic modifications subdue cellular inflammation, improve overall endothelial functions, reduce age-related systolic hypertension and vascular rigidity, and attenuate the actions of the renin-angiotensin-aldosterone system. Most observational and ecological studies support 25(OH)vitamin D having protective effects on the cardiovascular system. However, the association of vitamin D deficiency with cardiovascular diseases is based primarily on observational and ecological studies and thus, is a matter of controversy. Adequately powered, randomized controlled clinical trial data are not available to confirm these associations. Thus, to test the hypothesis that correction of vitamin D deficiency protects the cardiovascular system, well-designed, statistically powered, longer-term clinical trials are needed in persons with vitamin D deficiency. Nevertheless, the available data support that adequate vitamin D supplementation and/or sensible sunlight exposure to achieve optimal vitamin D status are important in the prevention of cardiovascular disease and other chronic diseases.

A study of serum Vitamin D level and its association with hypertension

Background

Evidence suggests that low levels of Vitamin D may adversely affect the cardiovascular (CV) system. Several studies have been done regarding the relation and possible causative role of Vitamin D in CV disorders and its well-known risk factors; however, there are limited studies in this part of the world. The aims were as follows: (1) To study the relation between serum Vitamin D level between nonhypertensive and hypertensive patients. (2) To study the relation of serum Vitamin D levels in patients with isolated systolic hypertension (ISH), isolated diastolic hypertension, systolo-diastolic hypertension, and their comparison vis-à-vis nonhypertensives.

Materials and Methods

A cross-sectional study was conducted with 154 patients attending medicine outpatient department of a tertiary care hospital of North Bengal from June 2012 to May 2013. The Vitamin D was measured by direct ELISA method. Blood pressure (BP) measurements were done. Statistical analysis was done by using SPSS 16.0 for Windows.

Results

The Vitamin D level in the hypertensive group was 22.36 ± 12.64; ISH Group was 22.04 ± 14.26; the isolated diastolic hypertension (IDH) Group was 18.82 ± 0.00; and the systolo-diastolic hypertensives (SDH) Group was 22.67 ± 12.51. Then, the mean value of Vitamin D in nonhypertensive Group (27.47 ± 13.43) was significantly (P < 0.05) higher than IDH, SDH, and the hypertensive as a whole groups. The relation with ISH Group also reached near significance (P = 0.074). There was a negative correlation with BP and serum Vitamin D. This remained statistically significant (P = 0.044) for systolic BP (SBP) and near significant (P = 0.075) for mean arterial pressure. In population having serum Vitamin D <30 ng/ml (deficient or insufficient), the negative correlation relationship between SBP and serum Vitamin D remains statistically significant (P = 0.010).

Conclusion

Among the hypertensives, SDH shows significantly lower levels of serum Vitamin D. The patients with ISH show a trend, though not statistically significant, toward a lower level of Vitamin D compared to the nonhypertensive population.

Association between Serum Parathyroid Hormone Levels and the Prevalence of Atrial Fibrillation: the Dong-gu Study

Background and Objectives

We aimed to investigate the association between serum parathyroid hormone (PTH) levels and the prevalence of atrial fibrillation (AF) in a population based study.

Methods

This study included a total of 9,007 community-dwelling Koreans aged 50 years and over who were enrolled in the Dong-gu study from 2007 to 2010. Electrocardiograms were recorded from the subjects using the HP-PageWriter 200 M1771A. All potential cases of AF were determined by 2 cardiologists. PTH concentration was measured by a chemiluminescent microparticle immunoassay. Multiple logistic regression analysis was used to evaluate the relationship between the quartiles of PTH and AF, adjusting for potential confounders.

Results

The prevalence of AF was 2.41% in males and 0.9% in females and increased with advanced age in both genders. The median and interquartile range (IQR) of serum PTH was 39.5 pg/mL (IQR, 30.6–50.8), which was significantly higher in patients with AF than in patients without AF (p<0.001). The prevalence of AF increased with increasing PTH quartile (0.8%, 0.9%, 1.6%, and 2.8% in the lowest, second, third, and highest PTH quartiles, respectively; p<0.001). Multivariable logistic analysis adjusted for cardiovascular risk factors showed the highest quartile of serum PTH levels was associated with a higher prevalence of AF than the lowest quartile (odds ratio, 3.34; 95% confidence interval, 1.93–5.78).

Conclusions

Higher levels of serum PTH were associated with higher prevalence of AF. Further studies are needed to determine whether this association is present in other populations and in a prospective study setting.

Relationship between Serum 25-hydroxy-vitamin D Concentration and Risk of Metabolic Syndrome in Patients with Fatty Liver

Background

The vitamin D deficiency rate in Koreans is still high and dietary intake is insufficient. The purpose of this study was to provide basic data for the management of metabolic syndrome (MetS) by analyzing the effect of vitamin D levels on the MetS in patients with fatty liver.

Methods

We analyzed the MetS ratio and serum 25-hydroxy-vitamin D (25[OH]D) concentration in 151 adults diagnosed with fatty liver by using obesity index and blood profiles. We collected data on demographic factors, nutrient intake, and lifestyle habits.

Results

The mean 25(OH)D concentration of all subjects was 14 ng/mL and the insufficiency and deficiency rates were 40.4% and 29.8%. The proportion of MetS was 38.4% and the mean 25(OH)D level of MetS group was 12.1 ng/mL. Low-density lipoprotein cholesterol, triglyceride, and blood glucose were higher in the MetS group than in the normal group, and the waist circumference of the male was significantly higher than that of the normal group. The results showed that the lower the vitamin D concentration, the higher the risk of MetS (odds ratio, 1.47, 95% confidence interval, 0.98–2.81; P=0.043).

Conclusions

These results suggest that serum 25(OH)D levels may be a risk factor for MetS in patients with fatty liver.

Serum levels of 25-hydroxyvitamin D predicts infarct volume and mortality in ischemic stroke patients

BACKGROUND

The aim of this study is to determine 25-hydroxyvitamin D [25(OH) D] levels in serum, and investigate their associations with cardiovascular disease (CVD) or all-cause mortality in a 1-year follow-up study in patients with first-ever ischemic stroke.

METHODS

From November 2013 to October 2015, 387 consecutive patients with ischemic stroke admitted to our hospital were identified. Serum 25(OH) D levels were measured at admission. Infarct volume was measured using diffusion-weighted imaging (DWI). The primary end point was CVD mortality among 1year. The secondary end point was all-cause mortality.

RESULTS

In this study, 387 patients were included. A statistically significant negative correlation between serum 25(OH) D level and infarct volume was found (r=-0.442; P<0.001). There were 74 patients (19.1%, 95%CI: 15.2%-23.0%) died, including 36 CVD mortality (9.3%, 95CI%: 6.4%-12.2%). The mortality distribution across the 25(OH) D quartiles ranged between 39.2% (first quartile) to 5.2% (fourth quartile) for all-cause mortality and between 18.6% (first quartile) to 2.1% (fourth quartile) for CVD mortality. In a multivariate model using the first quartiles of 25(OH) D vs. quartiles 2 through 4 together with the clinical variables, the marker displayed prognostic information CVD mortality: OR for first quartile, 3.06 [95% CI, 2.16-4.95]; all-cause mortality: OR for first quartile, 2.76 [95% CI, 2.01-4.32].

CONCLUSIONS

The data show serum levels of 25(OH) D at admission is useful prognostic marker of CVD and all-cause mortality in Chinese patients with ischemic stroke.

25-hydroxyvitamin D is associated with adiposity and cardiometabolic risk factors in a predominantly vitamin D-deficient and overweight/obese but otherwise healthy cohort

Vitamin D deficiency has reached epidemic proportions worldwide and has recently been linked to cardiometabolic risk factors including obesity, insulin resistance, hypertension, dyslipidemia, as well as type 2 diabetes and cardiovascular disease. The objective of this study was to examine the associations between circulating 25-hydrovitamin D (25(OH)D) levels and cardiometabolic risk factors using direct measures of adiposity, glucose intolerance, and insulin resistance, as well as lipids, blood pressure, and plasma markers of inflammation. We measured circulating 25(OH)D, physical activity (International Physical Activity Questionnaire- IPAQ), anthropometry (body mass index (BMI), waist-to-hip ratio (WHR), % body fat (dual energy X-ray absorptiometry)), metabolic parameters (fasting and 2-h plasma glucose levels during oral glucose tolerance test; insulin sensitivity (M, hyperinsulinaemic-euglycaemic clamp), and cardiovascular and inflammatory profiles (blood pressure (BP), pulse pressure (PP), mean arterial pressure (MAP), plasma lipid levels, white blood cell count (WBC), and plasma high-sensitivity C-reactive protein levels (hsCRP)) in 111 healthy, non-diabetic adults (66 males/45 females; age 31.1±9.2years; % body fat 36.0±10.2%). Mean 25(OH)D was 39.8±19.8 nmol/L with no difference between genders (p=0.4). On univariate analysis, 25(OH)D was associated with% body fat (r=-0.27; p=0.005), 2-h glucose (r=-0.21; p=0.03), PP (r=0.26; p=0.006), and insulin sensitivity (r=0.20, p=0.04), but not with age, BMI, WHR, fasting glucose, BP, MAP, lipids, or inflammatory markers (all p>0.05). After adjusting for age and sex, 25(OH)D remained associated with% body fat (β=-0.12%; p=0.003), 2-h glucose (β=-0.13mmol/L; p=0.02), PP (β=0.12mmHg; p=0.009), and insulin sensitivity (β=0.22mg/kg/min; p=0.03), and became associated with fasting glucose (β=-0.04mmol/L; p=0.04) and hsCRP (β=-0.51mg/L; p=0.04). After adjusting for age, sex, and % body fat, 25(OH)D was no longer associated with insulin sensitivity, 2-h glucose, or hsCRP, but remained associated with fasting glucose (β=-0.05mmol/L; p=0.03) and PP (β=0.10mmHg; p=0.03). 25(OH)D remained associated with fasting glucose (β=-0.06mmol/L; p=0.02) after hsCRP and physical activity were added to the model with % body fat, age, and sex. ​These cross-sectional data suggest that associations between vitamin D and cardiometabolic risk among healthy, non-diabetic adults are largely mediated by adiposity. Large-scale intervention and mechanistic studies are needed to further investigate whether vitamin D has an independent role in the prevention and/or management of cardiometabolic risk and disease.

Evaluation of the Relationship between Serum 25-Hydroxy Vitamin D and Hypertension in Hamadan, Iran-A Case Control Study

INTRODUCTION

Hypertension or high blood pressure is one of the main reasons of fatality in the world. The role of vitamin D in developing hypertension has not been proved yet. Some studies have shown positive correlation between low serum vitamin D level and hypertension. Due to this fact, recognising hypertension risk factors such as potential impact of low serum vitamin D level seems to be required.

AIM

This study was conducted to evaluate potential impact of serum vitamin D level on hypertension.

MATERIALS AND METHODS

This case-control study had 188 subjects including 55 cases suffering from hypertension and 133 controls with normal blood pressure in Hamadan, Iran. After taking the medical history and physical examination, 5 cc of their blood was taken to measure their serum 25-Hydroxyvitamin D [25(OH)D] level through ELISA test. Data analysis was done by version 16.0 of SPSS software and used independent sample t-test and Chi-square test for related comparisons.

RESULTS

Mean and standard deviation of serum 25(OH)D level in patients suffering from hypertension was 13.10±9.7 ng/ml and in control group was 20.87±10.34 ng/ml. This variance was statistically significant (p<0.001). Mean serum 25(OH)D level in both case and control groups was measured after gender and age stratification. Mean serum 25(OH)D level in cases and controls was 13.12±11.4 ng/ml and 21.38±11.47 ng/ml in males (p=0.016) and 13.10±9.91 ng/ml and 19.19±10.55 ng/ml (p=0.004) in females, respectively. Mean serum 25(OH)D level in under 50-year-old was 10.82±8.73 ng/ml and 20.07±11.17 ng/ml in cases and controls respectively (p<0.001). In over 50-year-old, there was no significant relationship between mean serum 25(OH)D and blood pressure levels (p>0.05).

CONCLUSION

According to this study, reverse relationship between serum 25(OH)D and blood pressure levels was seen.

Serum vitamin D levels in Indian patients with retinal venous occlusions

Purpose

To estimate serum vitamin D (25 OH D) level in patients of retinal vein occlusion (RVO) and compare it with age-matched controls.

Methods and material

Forty patients above 18 years of age with retinal vein occlusion and forty age-matched controls underwent serum vitamin D (Vit D) level estimation using a standard protocol. Student’s t test was used to analyse differences between the mean of two groups.

Results

The mean age in RVO and control group was 60.25 and 60.73 years respectively. The mean (±SD) level of vitamin D in RVO patients was 13.68 (±4.58) ng/mL (range 5.5–24.8), and the 95% CI of mean was 12.21–15.14 with SD 4.58 while in control group it was 23.03 (±2.89) ng/ml (range 18.4–30.1) with 95% CI of mean being 22.11–23.96 with SD 2.89 (p value of <0.005). While comparing the level of Vitamin D based on type of occlusion the mean level of Vit D in CRVO patients was 15.36 (SD 5.30) and in BRVO it was 12.77 (SD 3.96) which was statistically not significant (p = 0.08). The odds ratio calculated for RVO cases versus controls was 133.33 which was statistically significant (P < 0.05).

Conclusions

There is a paucity of published literature on level of Vit D in RVO. This study shows significantly lower levels of serum vitamin D in Indian patients with retinal vein occlusion as compared to age matched controls. Establishment of this correlation has possible implications for prophylaxis or treatment of RVOs.

Dysfunctional immunometabolic effects of vitamin D deficiency, increased cardiometabolic risk. Potential epidemiological alert in America?

Vitamin D deficiency is a serious public health problem worldwide that affects not only skeletal health, but also a wide range of acute and chronic diseases. However, there is still skepticism because of the lack of randomized, controlled trials to support association studies on the benefits of vitamin D for non-skeletal health. This review was based on articles published during the 1980-2015 obtained from the Cochrane Central Register of controlled trials, MEDLINE and PubMed, and focuses on recent challenges with regard to the definition of vitamin D deficiency and how to achieve optimal serum 25-hydroxyvitamin D levels from dietary sources, supplements, and sun exposure. The effect of vitamin D on epigenetic fetal programming and regulation of genes that may potentially explain why vitamin D could have such lifelong comprehensive health benefits is reviewed. Optimization of vitamin D levels in children and adults around the world has potential benefits to improve skeletal health and to reduce the risk of chronic diseases, including some types of cancer, autoimmune diseases, infectious diseases, type 2 diabetes mellitus, and severe cardiovascular disorders such as atherothrombosis, neurocognitive disorders, and mortality.

Does Vitamin D Deficiency Lead to Hypertension?

Hypertension (HTN) or high blood pressure is one of the most chronic and deadliest disorders in the world. There are many risk factors responsible for HTN which include age, race, using tobacco, high salt intake, etc. One of the risk factors we would like to highlight is low vitamin D levels. While there is strong evidence that Vitamin D plays an important role in maintaining bone and muscle health, there has been recent debate regarding its role in hypertension. However, there are many studies that have shown an indirect relation between 25-hydroxyvitamin D serum level and blood pressure. However, we suggest that more studies, especially randomised trials, should be conducted.