Effect of calcium and vitamin D supplementation on blood pressure: the Women's Health Initiative Randomized Trial

The Effects of Vitamin D Supplementation on C-Reactive Protein and Systolic and Diastolic Blood Pressure in Postmenopausal Women: A Meta-Analysis and Systematic Review of Randomized Controlled Trials

BACKGROUND

An inverse relationship between vitamin D supplementation and C-reactive protein (CRP) and hypertension has been reported, mostly through observational data. This inverse relationship, however, has not been confirmed in randomized controlled trials (RCTs). A meta-analysis of RCTs is needed to provide more robust evidence.

OBJECTIVE

This systematic review of RCTs was conducted to assess the effect of vitamin D supplementation on CRP, systolic blood pressure (SBP), and diastolic blood pressure (DBP) in postmenopausal women.

METHODS

Four databases (PubMed, Web of Science, Embase, and Scopus) were systemically searched to identify relevant RCTs published in international scientific journals up to January 2023. Changes from baseline and SDs of CRP, SBP, and DBP were compared between postmenopausal women who received vitamin D supplementation and those who did not (controls). These parameters were applied to compute the overall effect sizes using the random-effects model. Data were summarized as mean difference (MD) with 95% CI. Heterogeneity among arms was scrutinized using the Cochrane's Q test and I2 statistic. Publication bias was judged by means of funnel plots and Egger's test.

RESULTS

Seven studies with 6 arms on CRP, 6 arms on SBP, and 6 arms on DBP were included in the meta-analysis. Combined effect sizes suggested a significant effect of vitamin D supplementation on CRP (MD = -0.65 mg/L; 95% CI -0.93 to -0.37 mg/L; P < .001). In addition, CRP concentrations were significantly reduced after vitamin D supplementation in studies with a duration of more than 3 months (MD = -0.91 mg/L; 95% CI -1.37 to -0.45 mg/L; P < .001) and studies involving doses of ≤1,000 IU/d (MD = -2.10 mg/L; 95% CI -2.51 to -1.68 mg/L; P < .001). Vitamin D supplementation did not reduce SBP significantly (MD = -1.06 mm Hg; 95% CI -2.43 to 0.30 mm Hg; P = .127) and DBP (MD = 0.003 mm Hg; 95% CI -0.86 to 0.86 mm Hg; P = .994) levels compared with control groups.

CONCLUSIONS

This meta-analysis concluded that vitamin D supplementation is associated with reduced CRP concentrations among postmenopausal women.

Role of Vitamin D in Management of Diabetes and Unresolved Cardiovascular Diseases

BACKGROUND

Vitamin D deficiency is becoming a widely recognized global health issue. Serum values of 25-(OH) vitamin D (<20 ng/ml) are used to identify vitamin D deficiency. By prompting vascular endothelial cells to activate their nuclear receptor in cardio-myocytes, Vitamin D regulates obesity, Renin-angiotensin system (RAS), energy consumption, and pancreatic cell function. Vitamin D deficiency has been associated with diabetes, asthma, hyperlipidaemia, and pulmonary hypertension in humans.

METHODS

PubMed and Google Scholar databases were utilised to search the literature on vitamin D and related diseases.

RESULT

It is also linked to an elevated risk of death and heart disease. On the other hand, metaanalyses of vitamin D intervention and trials have found no substantial changes in insulin sensitivity, lipid markers, or blood pressure, which result in the association between deficiency of vitamin D and cardiovascular disease.

CONCLUSION

In this review, we present the most recent research on the effects of Vitamin D therapy on various cardiovascular diseases and diabetes, and explain the underlying mechanisms.

Long-term aircraft noise exposure and risk of hypertension in postmenopausal women

BACKGROUND

Studies of the association between aircraft noise and hypertension are complicated by inadequate control for potential confounders and a lack of longitudinal assessments, and existing evidence is inconclusive.

OBJECTIVES

We evaluated the association between long-term aircraft noise exposure and risk of hypertension among post-menopausal women in the Women's Health Initiative Clinical Trials, an ongoing prospective U.S.

COHORT

METHODS

Day-night average (DNL) and night equivalent sound levels (Lnight) were modeled for 90 U.S. airports from 1995 to 2010 in 5-year intervals using the Aviation Environmental Design Tool and linked to participant geocoded addresses from 1993 to 2010. Participants with modeled exposures ≥45 A-weighted decibels (dB [A]) were considered exposed, and those outside of 45 dB(A) who also did not live in close proximity to unmodeled airports were considered unexposed. Hypertension was defined as systolic/diastolic blood pressure ≥140/90 mmHg or inventoried/self-reported antihypertensive medication use. Using time-varying Cox proportional hazards models, we estimated hazard ratios (HRs) for incident hypertension when exposed to DNL or Lnight ≥45 versus <45 dB(A), controlling for sociodemographic, behavioral, and environmental/contextual factors.

RESULTS/DISCUSSION

There were 18,783 participants with non-missing DNL exposure and 14,443 with non-missing Lnight exposure at risk of hypertension. In adjusted models, DNL and Lnight ≥45 db(A) were associated with HRs of 1.00 (95% confidence interval [CI]: 0.93, 1.08) and 1.06 (95%CI: 0.91, 1.24), respectively. There was no evidence supporting a positive exposure-response relationship, and findings were robust in sensitivity analyses. Indications of elevated risk were seen among certain subgroups, such as those living in areas with lower population density (HRinteraction: 0.84; 95%CI: 0.72, 0.98) or nitrogen dioxide concentrations (HRinteraction: 0.82; 95%CI: 0.71, 0.95), which may indicate lower ambient/road traffic noise. Our findings do not suggest a relationship between aircraft noise and incident hypertension among older women in the U.S., though associations in lower ambient noise settings merit further investigation.

Salivary Calcium Level and Its Correlation with Salivary pH, Salivary Volume, and Calcium Intake in Hypertensive Female Patients with Different Blood Sugar Levels

Aims

This study aimed to evaluate the salivary calcium level and its correlation with salivary pH, salivary volume, and calcium intake in hypertensive female patients with different blood sugar levels.

Materials and Methods

This cross-sectional study included 49 female subjects with hypertension. Subjects were divided into three groups based on the HbA1c test: normal, prediabetes, and diabetes. Unstimulated whole saliva was collected using the spitting method. Salivary calcium levels were evaluated using an Atomic Absorption Spectrophotometer. Salivary pH was obtained using a universal indicator pH paper test. Calcium intake was assessed by a semi-quantitative food frequency questionnaire. The Kruskal-Wallis test was used to compare salivary parameters and total calcium intake within study groups. Spearman rank correlation and multiple regression analysis were used to evaluate the correlation between salivary calcium levels and all variables in the study.

Results

No significant difference in salivary calcium, volume, pH, and total calcium intake was observed within the study groups. However, a significant correlation was found between salivary calcium levels and salivary pH in hypertensive females with normal blood glucose levels. Moreover, salivary calcium levels have a significant correlation with systolic blood pressure in prediabetes and diabetes groups.

Conclusions

This study found a decrease in all salivary parameters (calcium, pH, and volume) as well as a low calcium intake in hypertensive females, despite no significant difference found in groups with different blood glucose levels. Blood glucose levels appeared to be a confounder in the relationship between salivary calcium with salivary pH and systolic blood pressure.

Overview of Nutraceuticals and Cardiometabolic Diseases following Socio-Economic Analysis

The importance of functional food and nutraceutical products to deal with cardiometabolic diseases (CMDs) and metabolic syndrome (MetS) has gained attention in the past few years. The aim of this narrative review is to highlight the potential and effectiveness of nutraceutical in the improvement of CMDs and MetS biomarkers, alongside their burden of disease and economic health expenditure. A science database search was conducted between May and June 2021. A total of 35 studies were included in this paper. We included male and female subjects, children, and adults, in good health or with cardiovascular or metabolic disease. CMDs and MetS have gradually become worldwide health problems, becoming two of the major causes of morbidity and mortality in western countries. The results indicate a positive link between daily consumption of nutraceutical products and an improvement in cardiometabolic and anthropometric biomarkers. In this paper we included a wide range of nutraceutical products. Most of them showed promising data, indicating that nutraceuticals could provide a new therapeutic treatment to reduce prevalence and pharmaceutical expenditures attributed to CMDs and MetS. Unfortunately, there is a huge vacuum of data on nutraceutical usage, savings, and burden reduction. Therefore, further clinical and pharmaco-economic research in the field is highly required.

The effect of calcium and vitamin D supplements on blood pressure in postmenopausal women: myth or reality?

Hypertension is a highly prevalent disease with serious cardiovascular and renal complications. Many studies have demonstrated a weak correlation between the consumption of calcium (or calcium plus vitamin D) and blood pressure, suggesting that calcium supplements might reduce blood pressure. However, the results to date remain controversial. In this study, we assessed the effect of calcium and vitamin D supplementation on the blood pressure of postmenopausal women with hypertension as a population group in which the use of calcium supplements is prevalent. This triple-blind randomized clinical trial enrolled 98 women of postmenopausal age with hypertension in 2019. The study period was 8 weeks with close follow-up. We used 24-h ambulatory blood pressure monitoring to record the initial and final blood pressure in all participants. The changes in both the mean systolic (p = 0.047) and diastolic blood pressure (p = 0.015) were suggestive of an increase in blood pressure after consuming calcium and vitamin D supplements. Among patients who had been using calcium channel blockers, calcium and vitamin D supplementation caused a notable increase compared to baseline systolic (p = 0.019) and diastolic blood pressures (p = 0.001). The present results differ from those of previous studies. This suggests that calcium supplementation for postmenopausal women with hypertension requires the close observation of blood pressure to prevent any further increase, especially in women who are being treated with calcium channel blockers (clinicaltrial.gov registration: NCT04618952).

Evaluating agreement between bodies of evidence from randomized controlled trials and cohort studies in medical research: a meta-epidemiological study

BACKGROUND

Randomized controlled trials (RCTs) and cohort studies are the most common study design types used to assess the treatment effects of medical interventions. To evaluate the agreement of effect estimates between bodies of evidence (BoE) from randomized controlled trials (RCTs) and cohort studies and to identify factors associated with disagreement.

METHODS

Systematic reviews were published in the 13 medical journals with the highest impact factor identified through a MEDLINE search. BoE-pairs from RCTs and cohort studies with the same medical research question were included. We rated the similarity of PI/ECO (Population, Intervention/Exposure, Comparison, Outcome) between BoE from RCTs and cohort studies. The agreement of effect estimates across BoE was analyzed by pooling ratio of ratios (RoR) for binary outcomes and difference of mean differences for continuous outcomes. We performed subgroup analyses to explore factors associated with disagreements.

RESULTS

One hundred twenty-nine BoE pairs from 64 systematic reviews were included. PI/ECO-similarity degree was moderate: two BoE pairs were rated as "more or less identical"; 90 were rated as "similar but not identical" and 37 as only "broadly similar". For binary outcomes, the pooled RoR was 1.04 (95% CI 0.97-1.11) with considerable statistical heterogeneity. For continuous outcomes, differences were small. In subgroup analyses, degree of PI/ECO-similarity, type of intervention, and type of outcome, the pooled RoR indicated that on average, differences between both BoE were small. Subgroup analysis by degree of PI/ECO-similarity revealed high statistical heterogeneity and wide prediction intervals across PI/ECO-dissimilar BoE pairs.

CONCLUSIONS

On average, the pooled effect estimates between RCTs and cohort studies did not differ. Statistical heterogeneity and wide prediction intervals were mainly driven by PI/ECO-dissimilarities (i.e., clinical heterogeneity) and cohort studies. The potential influence of risk of bias and certainty of the evidence on differences of effect estimates between RCTs and cohort studies needs to be explored in upcoming meta-epidemiological studies.

Cardiometabolic Indices after Weight Loss with Calcium or Dairy Foods: Secondary Analyses from a Randomized Trial with Overweight/Obese Postmenopausal Women

The role of dairy foods and calcium/vitamin D supplements in cardiometabolic diseases is unknown. The objective of this secondary analysis is to investigate cardiometabolic risk factors changes after a 6-month weight-loss intervention in overweight/obese postmenopausal women divided in three groups: Ca+vitamin D supplements (S); low-fat dairy foods (D; 4−5 servings/day); or control/placebo pills (C), as complements to hypocaloric diets. The original study focused on bone/body composition. This analysis included blood pressure (BP), and serum triglycerides, lipids (including apoproteins Apo1 and ApoB), adipokines, and C-reactive protein in n = 97 participants who finished with complete data points. Systolic BP decreased 5.1%, 4.8%, and 1.8% in S, D, and C groups, respectively (p < 0.05 for S and D vs. baseline and vs. C at 6 months). Reduction in triglycerides and ratio of total cholesterol (TC)/high-density lipoproteins cholesterol (HDL-C) was the highest in S, while the reduction in TC and LDL-C was the highest in D group (all p < 0.05). Leptin and ApoB significantly decreased and adiponectin and ApoA1 increased in all groups. In conclusion, although the C group’s participants experienced an improvement in some of the cardiometabolic indices with weight loss, those in the S and D groups showed significantly better results in most of the outcomes, indicating the beneficial effects of low-fat dairy foods and/or Ca+vitamin D intake as complements to a hypocaloric diet.

Association between serum calcium level and hemorrhagic progression in patients with traumatic intraparenchymal hemorrhage: Investigating the mediation and interaction effects of coagulopathy

In this study, we investigate the association of serum calcium with coagulopathy and hemorrhagic progression contusion (HPC) in patients with traumatic intraparenchymal hemorrhage (tIPH), and further explored the interaction and mediation effect between serum calcium as well as coagulopathy on HPC. Retrospective analyses of patients with tIPH admitted to the First Affiliated Hospital of Wenzhou Medical University between January 2016 to December 2019. The clinical data, coagulation parameters, and serum calcium levels were collected for further analysis. Multivariate logistic regression analysis was applied to identify the association of serum calcium level with coagulopathy and HPC. Causal mediation analysis (CMA) and additive interaction model were used to estimate the interaction and mediation effect between serum calcium as well as coagulopathy on HPC. Additionally, we repeated the analysis using corrected calcium. A total of 473 patients were included in this study. Of these, 54 (11.4%) patients had hypocalcemia at admission, 105 (22.2%) presented with coagulopathy, and 187 (39.5%) experienced HPC. Admission serum calcium level in patients presented with coagulopathy and HPC were 8.84 [IQR: 8.44-9.40] and 8.92 [IQR: 8.48-9.40] mg/dL respectively, which were significantly lower than that of patients without (9.10 [IQR: 8.68-9.88] and 9.12 [IQR: 8.72-9.89] mg/dL; all p < 0.001). Multivariate logistic regression analysis identified that hypocalcemia emerged as an independent risk factor for coagulopathy and HPC. However, no significant interaction was detected between hypocalcemia and coagulopathy. CMA showed that the mediator coagulopathy explained 24.4% (95% CI: 4.7-65.0%; p = 0.006) of the association between hypocalcemia and HPC. Moreover, comparable results were held using corrected calcium as well. Admission serum calcium level is associated with the HPC for patients with tIPH and this relationship is partially mediated by coagulopathy, but no significant interaction is detected. Further studies are needed to validate the findings and explore its mechanisms.

Could Vitamin D Be Effective in Prevention of Preeclampsia?

Prevention of preeclampsia (PE) remains one of the most significant problems in perinatal medicine. Due to the possible unpredictable course of hypertension in pregnancy, primarily PE and the high complication rate for the mother and fetus/newborn, it is urgent to offer pregnant women in high-risk groups effective methods of preventing the PE development or delaying its appearance. In addition, due to the association of PE with an increased risk of developing cardiovascular diseases (CVD) in later life, effective preeclampsia prevention could also be important in reducing their incidence. Ideal PE prophylaxis should target the pathogenetic changes leading to the development of PE and be safe for the mother and fetus, inexpensive and freely available. Currently, the only recognized method of PE prevention recommended by many institutions around the world is the use of a small dose of acetylsalicylic acid in pregnant women with risk factors. Unfortunately, some cases of PE are diagnosed in women without recognized risk factors and in those in whom prophylaxis with acetylsalicylic acid is not adequate. Hence, new drugs which would target pathogenetic elements in the development of preeclampsia are studied. Vitamin D (Vit D) seems to be a promising agent due to its beneficial effect on placental implantation, the immune system, and angiogenic factors. Studies published so far emphasize the relationship of its deficiency with the development of PE, but the data on the benefits of its supplementation to reduce the risk of PE are inconclusive. In the light of current research, the key issue is determining the protective concentration of Vit D in a pregnant woman. The study aims to present the possibility of using Vit D to prevent PE, emphasizing its impact on the pathogenetic elements of preeclampsia development.

Hormone therapy formulation, dose, route of delivery, and risk of hypertension: findings from the Women's Health Initiative Observational Study (WHI-OS)

OBJECTIVE

Using data from the Women's Health Initiative Observational Study (WHI-OS), to determine the role of estrogen formulation, dose, route of delivery, and its combination with different progestogens on the risk for hypertension in the WHI-OS.

METHODS

After excluding women with diagnosed hypertension, receiving antihypertensive medication, presenting with elevated blood pressure ( ≥ 140/90), and those not taking menopausal hormone therapy at baseline, 19,986 women remained eligible for the analyses. Using hierarchal modeling, proportional hazard rate calculation, and linear and logistic regression analyses, we evaluated incident treated hypertension and mean systolic and diastolic blood pressure changes at 3 years. Multivariable models were adjusted for age, race/ethnicity, education, smoking, physical activity, body mass index, history of treated diabetes, history of prescription medicines for high cholesterol, alcohol intake, hysterectomy, and bilateral oophorectomy.

RESULTS

At 3 years, and compared with conjugated estrogens (CEE) with or without a progestin, the odds for newly treated hypertension were lower in women who used transdermal estradiol (0.85, 95% CI, 0.73-1.00) or oral estrone sulphate dominant preparations (0.83, 0.72-0.96). The odds of incident treated hypertension after 3 years did not vary according to dose of estrogen. The mean measured systolic blood pressure was minimally lower with transdermal estradiol (-1.20, 95% CI, -1.97 to -0.44) mm Hg and other oral Estrone dominant preparations (-0.83, 95% CI, -1.51 to -0.16) mm Hg at 3 years. For a given estrogen type, the magnitudes of the hazard ratio were similar for estrogen-alone compared with estrogen plus a progestogen. For women 10 or more years past menopause when they entered, the HR for incident self-reported treated hypertension was 1.26 (95% CI, 1.09-1.46) with higher dose CEE compared with 0.625 mg CEE. It was 0.87 (95% CI, 0.68-1.13) when given to women who were < 10 years after menopause when they entered the WHI-OS.

CONCLUSION

The risk of treated hypertension differed by formulation, dose, and years since menopause.

An evidence-based appraisal of complementary and alternative medicine strategies for the management of hypertension

: Hypertension is a major risk factor for cardiovascular disease and all-cause mortality. Numerous antihypertensive medications and lifestyle changes have proven effective for the reduction of blood pressure (BP). Over the past few decades, the emergence of complementary and alternative medicine (CAM)-based strategies to lower BP have broadened the therapeutic armamentarium for hypertension. CAM is defined as a group of heterogeneous medical treatments that are used to enhance the effect of standard therapy, or, conversely, are implemented as an alternative to standard practice. The available body of evidence does substantiate the BP-lowering effects of certain CAM-based therapies in individuals with and without established hypertension. Collectively, alternative strategies for BP reduction have undergone less rigorous testing than traditional BP-lowering strategies and the lack of robust clinical data has greatly hampered the broad-scale adoption of CAM therapies into clinical practice. Despite these limitations, CAM-based therapies for the reduction of BP require consideration as they could offer substantial public health benefits given the high prevalence of hypertension in the general population. This article reviews some of the most promising CAM-based therapies for the reduction of BP and cardiovascular outcomes based on the current literature.

Calcium prescription by Indian orthopaedic surgeons: A survey and a review of literature

BACKGROUND

Orthopaedic surgeons prefer calcium supplement for various pathologies like fracture, osteoporosis, chronic musculoskeletal pain, yet there is no proper evidence to support the benefits of taking them regularly. The average requirement for calcium is around 500-1000 mg/day for a healthy adult, this amount of calcium is not achieved by diet, especially in developing countries like India. Despite this, the serum calcium level remains unaltered, due to the well-controlled absorption and excretion of calcium by the human body. As there is no clarity over the dose, duration and the prefered calcium salts, we constructed a survey to find the preferred dose, duration, the preferred calcium salts among orthopaedic surgeons, and to give an in-depth review of literature about dose, duration, timing, preferred calcium salt and various other calcium-related queries.

MATERIALS AND METHOD

The survey included 15 pre-structured questionnaires; these questions were formatted and validated by senior surgeons and other specialists after a through a review of calcium-related literature. These questionnaires were used in a pilot study conducted within the department and were later modified and separated into 7 sections. Data were collected by both online survey (google forms) and direct interviews.

RESULT AND CONCLUSION

128 Orthopedic surgeons responded. The total number of response obtained was 2355. Unanswered questions were 152. From the survey, it was found that most orthopaedic surgeons prefer to prescribe calcium routinely (55.46%). The commonly used calcium salt was calcium carbonate (47.65%), followed by citrate (32.8%). 42.18% were not aware of the efficiency of prescribing calcium in divided doses. Most responded that calcium is not to be given for patients with renal stones, but literature shows that calcium prescribed reduces the recurrence of commonest kidney stones, calcium oxalate stones.

High-dose Cholecalciferol Supplementation Reducing Morning Blood Pressure in Normotensive DM1 Patients

BACKGROUND

Vitamin D (VD) deficiency has been related to several endocrine metabolic and cardiovascular diseases. The effect of VD supplementation on blood pressure (BP) in patients with diabetes is controversial.

OBJECTIVE

The aim of this study was to evaluate high-dose vitamin D supplementation effects on blood pressure of normotensive patients with diabetes mellitus 1 (DM1) patients by 24-hour ambulatory blood pressure monitoring (ABPM).

METHODS

We performed a clinical trial including 35 DM1 normotensive patients, who received doses of 4,000 or 10,000 IU/day of cholecalciferol for 12 weeks according to previous VD levels. They underwent 24-hour ABPM, along with glycated hemoglobin, creatine, lipids profile and PCRus dosage before and after VD supplementation.

RESULTS

We found an expressive reduction of systolic and diastolic morning blood pressures (117±14 vs 112±14, p<0,05; 74±9 vs 70±10 mmHg, p<0,05, respectively) with no changes in other pressoric markers. Besides, we noticed a relationship between levels of VD after supplementation and diastolic morning blood pressure (r= -0,4; p<0.05).

CONCLUSION

Our study suggests an association between supplementation of high doses of vitamin D and the reduction of morning blood pressure in normotensive DM1 patients.

Association of serum 25-Hydroxy vitamin D with total and regional adiposity and cardiometabolic traits

Background

Lower serum 25-hydroxyvitamin D [25(OH)D] is associated with greater adiposity and adverse cardiometabolic risk profile. The evidence is inconsistent among South Asian Indians. We aimed to examine associations between 25(OH)D and cardiovascular (CVD) risk markers in a rural and urban cohort from South India.

Subjects/Methods

In this cross sectional study, 373 individuals (men, n = 205) underwent detailed CVD risk marker assessment including anthropometry [body mass index (BMI), waist, (WC) and hip circumferences (HC)], body composition analysis using dual energy x-ray absorptiometry (DXA), blood pressure and biochemical analysis (glucose, insulin and lipids). The distribution of CVD risk factors were compared across serum 25(OH)D levels, stratified as deficiency (<20 ng/ml), insufficiency (20 to 29 ng/ml) and normal (≥30 ng/ml) levels. Multiple regression analysis, adjusting for potential confounders, was used to study associations of 25(OH)D with adiposity and cardiometabolic traits.

Results

The mean and standard deviation (SD) of age, BMI and 25(OH)D levels were 41.4 (1.1) years, 25.5 (4.8) kg/m² and 23.4 (10.4) ng/ml respectively. The prevalence of 25(OH)D deficiency was 39.9% in this cohort. Individuals in the 25(OH)D deficiency category had significantly higher mean (SD) BMI [26.6 (5.1) kg/m²], waist circumference [89.9 (12.5) cm] and total fat mass [20.6 (7.9) kg] compared with the Vitamin D sufficient group [BMI: 24.0 (4.4); WC 84.7 (12.0); total fat mass: 15.2 (6.8)]. Significantly inverse associations were observed with DXA measured total and regional fat depots with 25(OH)D levels, while anthropometric indices of adiposity showed significant inverse association only in women. After adjusting for total fat mass, no significant associations were observed between 25(OH)D and the cardiometabolic traits.

Conclusions

Our results confirm that lower 25(OH)D is independently associated with both total and regional adiposity, but not with cardiometabolic traits, in this population.

Effects of a multi-modal resistance exercise program and calcium-vitamin D3 fortified milk on blood pressure and blood lipids in middle-aged and older men: secondary analysis of an 18-month factorial design randomised controlled trial

PURPOSE

Physical activity and dietary interventions are recommended as front-line therapy for prevention and management of cardiovascular disease. This study investigated the independent and combined effects of low-fat, calcium-vitamin D₃ fortified milk and multi-modal exercise training on blood pressure (BP) and blood lipids in middle-aged and older men.

METHODS

This was a pre-planned secondary analysis of an 18-month, randomised controlled trial. Community-dwelling men aged 50-79 years (n = 180) were randomised into (i) exercise + fortified milk; (ii) fortified milk; (iii) exercise; or (iv) control. The low-fat milk (400 mL/day) was fortified with 1,000 mg/day calcium and 800 IU/day of vitamin-D₃, whilst the exercise intervention consisted of three sessions/week of resistance- and weight-bearing impact exercises. Resting BP and fasting lipids were assessed at baseline, 6 (lipids only), 12 and 18 months.

RESULTS

Mean ± SD serum 25(OH)D and calcium intake for the entire cohort at baseline was 86 ± 36 nmol/L and 1002 ± 397 mg/day, respectively, with 10% classified as vitamin-D insufficient and 58% reporting a calcium intake below 1000 mg/day. There were no exercise-by-fortified milk interactions, nor any main-group effects for exercise or milk on BP or lipids at any time. However, there were significant reductions from baseline to 18 months in systolic (mean change, 5-8 mmHg) and diastolic (4-6 mmHg) BP in the exercise, fortified milk and control groups. All results remained largely unchanged after adjusting for use of anti-hypertensive or lipid lowering medication, weight or fat mass, or only including men with hypertension (n = 89) or dyslipidemia (n = 130) at baseline.

CONCLUSION

Supplementation with low-fat, calcium + vitamin D₃ fortified milk and a multi-modal exercise program, alone or in combination, was not effective for improving BP or blood lipids in community-dwelling middle-aged and older men.

The Role of Serum Calcium Level in Intracerebral Hemorrhage Hematoma Expansion: Is There Any?

Spontaneous intracerebral hemorrhage (ICH) is a devastating form of stroke, with a high rate of mortality and morbidity. Even with the best current medical or surgical interventions, outcomes remain poor. The location and initial hematoma volume are strong predictors of mortality. Hematoma expansion (HE) is a further marker of poor prognosis that may be at least partly preventable. Several risk factors for HE have been identified, including baseline ICH volume, anticoagulation, and computed tomography angiography spot signs. Recent studies have shown the correlation of serum calcium (Ca⁺⁺) levels on admission with HE. Low serum Ca⁺⁺ level has been associated with larger hematoma volume at the time of presentation, HE, and worse outcome. Although the causal and mechanistic links between low serum Ca⁺⁺ level and HE are not well understood, several mechanisms have been proposed including coagulopathy, platelet dysfunction, and higher blood pressure (BP) in the context of low serum Ca⁺⁺ level. However, low serum Ca⁺⁺ level might be only a biomarker of the adaptive response due to acute inflammatory response following acute ICH. The purpose of the current review is to discuss the evidence regarding the possible role of low serum Ca⁺⁺ level on HE in acute ICH.

Effect of Calcium and Vitamin D Co-supplementation on Blood Pressure: A Systematic Review and Meta-Analysis

PURPOSE

Vitamin D and calcium insufficiency has been related to elevated blood pressure (BP) and cardiovascular complications. This systematic review and meta-analysis investigates the effect of calcium and vitamin D co-supplementation on BP.

METHODS

A systematic search was conducted of electronic databases, including Web of Sciences, MEDLINE, Scopus, EMBASE, and the Cochrane Library, along with searches of gray literature and reference lists from included trials. There were no language restrictions, and the databases were searched from inception to October 2019. Randomized controlled trials, using calcium and vitamin D co-supplementation and reporting mean systolic BP and/or diastolic BP (DBP) with SDs, were included in the systematic review. Articles were evaluated independently by 2 researchers based on inclusion and exclusion criteria. A random effects model was conducted to synthesize the data.

FINDINGS

Eight trials were included in the meta-analysis. Meta-analysis of these 8 trials indicated a nonsignificant reduction in systolic BP in the calcium and vitamin D co-supplementation group compared with control (standardized mean difference, -0.23; 95% CI, -0.52 to 0.06). Conversely, there was a statistically significant decrease in DBP (standardized mean difference, -0.29; 95% CI, -0.55 to -0.02). Subgroup analysis suggested that young adults achieve a greater reduction in DBP than other age groups.

IMPLICATIONS

Calcium and vitamin D co-supplementation can modulate DBP and should be investigated more specifically in large, well-designed trials of hypertensive populations. (Clin Ther. 2020;42:XXX-XXX) © 2020 Elsevier HS Journals, Inc.

The role of nutraceuticals in prevention and treatment of hypertension: An updated review of the literature

Hypertension (HTN) is a worldwide epidemic in both developed and developing countries. It is one of the leading causes of major health problems such as cardiovascular disease, stroke, and heart attack. In recent years, several studies have reported associations between specific dietary ingredients and improving HTN. Nutraceuticals are natural food components with pharmacological properties. Reports suggest that functional foods and nutraceutical ingredients might support patients to obtain the desired therapeutic blood pressure (BP) goals and reduce cardiovascular risks by modulating various risk factors such as oxidative stress, renin-angiotensin system hyperactivity, inflammation, hyperlipidemia, and vascular resistance. We review the recent clinical experiments that have evaluated the biological and pharmacological activities of several types of nutraceuticals, including sour tea, cocoa, common spices, vitamin C, vitamin E, lycopene, flavonoids, coenzyme Q10, milk's tripeptides, calcium, magnesium, polyunsaturated fatty acids, and prebiotics in preventing and treating HTN. This review summarizes recent knowledge about the impact of common nutraceuticals for the regulation of BP.

Vitamin D and Atherosclerotic Cardiovascular Disease

CONTEXT

A large body of experimental and observational data has implicated vitamin D deficiency in the development of cardiovascular disease. However, evidence to support routine vitamin D supplementation to prevent or treat cardiovascular disease is lacking.

DESIGN AND RESULTS

A comprehensive literature review was performed using PubMed and other literature search engines. Mounting epidemiological evidence and data from Mendelian randomization studies support a link between vitamin D deficiency and adverse cardiovascular health outcomes, but randomized trial evidence to support vitamin D supplementation is sparse. Current public health guidelines restrict vitamin D intake recommendations to the maintenance of bone health and prevention of fractures. Two recently published large trials (VITAL and ViDA) that assessed the role of moderate- to high-dose vitamin D supplementation as primary prevention for cardiovascular outcomes in the general population had null results, and previous randomized trials have also been generally negative. These findings from general population cohorts that are largely replete in vitamin D may not be applicable to chronic kidney disease (CKD) populations, in which the use of active (1α-hydroxylated) vitamin D compounds is prevalent, or to other high-risk populations. Additionally, recent trials in the CKD population, as well as trials using vitamin D analogs, have been limited.

CONCLUSIONS

Current randomized trials of vitamin D supplementation do not support benefits for cardiovascular health, but the evidence remains inconclusive. Additional randomized trials assessing larger numbers of participants with low baseline vitamin D levels, having longer follow-up periods, and testing higher vitamin D dosages are needed to guide clinical practice.

Vitamin D status among adults (18-65 years old) attending primary healthcare centres in Qatar: a cross-sectional analysis of the Electronic Medical Records for the year 2017

OBJECTIVES

To investigate the prevalence of vitamin D deficiency among individuals attending primary healthcare facilities in Qatar and to assess the association between vitamin D deficiency and some medical conditions in persons aged 18-65 years old.

SETTING

The study was undertaken in publicly funded primary healthcare services in the State of Qatar.

PARTICIPANTS

A total of 102 342 participants aged between 18 and 65 years old with a valid serum vitamin D test result during the year 2017.

OUTCOME MEASURES

Serum level <10 ng/mL (<25 nmol/L) was defined as severe vitamin D deficiency, a serum level of <20 ng/mL (<50 nmol/L) was defined as vitamin D deficiency and a serum level <30 ng/mL (<75 nmol/L) defined as vitamin D insufficiency.

RESULTS

The prevalence rate of severe vitamin D deficiency was 14.1% among study participants with no history of vitamin D replacement therapy in the previous months. The prevalence rate of vitamin D deficiency was as high as 71.4% and that of vitamin D insufficiency was up to 92.7%. None of the five chronic conditions explored in the study (diabetes, hypertension, asthma, stroke and cardiovascular disease) had an obvious association with severe vitamin D deficiency status in a bivariate analysis. However, multivariate modelling showed that (adjusting for age, gender, body mass index and nationality and each of the included chronic conditions) hypertension, cardiovascular diseases and stroke placed an individual at a higher risk of having an associated severe vitamin D deficiency status.

CONCLUSION

Although not comprehensive and nationally representative, this study is suggestive of a higher prevalence of vitamin D deficiency among young adults, females, Qatari nationality and those with higher body mass index. Multivariate modelling showed that hypertension, cardiovascular diseases and stroke were associated with a higher risk of severe vitamin D deficiency status.

Retrospective Analysis of Cardiovascular Disease Risk Parameters in Participants of a Preventive Health and Wellness Program

Lifestyle, dietary, and nutritional choices are important influencing parameters of cardiovascular disease (CVD) risk, the number one cause of morbidity and mortality globally. Our aims were to i) characterize CVD risk parameters using data from 7939 participants enrolled in a preventive health and wellness program between March 2010 and January 2017; and ii) evaluate intervention effects in 3,020 participants who returned for follow-up. Blood measurements (nutrient markers), CVD risk parameters (abdominal obesity, hypertension, hyperglycemia, hypertriglyceridemia, low high-density lipoprotein (HDL), insulin resistance, and inflammation), glycemic status (HbA1c), and insulin resistance (HOMA-IR) were assessed. Framingham and Reynold's risk scores were also calculated. After approximately one year of treatment (n = 3 020), mean arachidonic acid:eicosapentaenoic acid (AA:EPA) ratio, homocysteine, and HbA_lc concentrations were significantly reduced; other risk parameters did not improve but mean values remained within reference ranges. Excluding participants taking related medications, 38.8%, 37.2%, 38.0%, 42.5%, and 59.7% of those with hyperglycemia, hypertriglyceridemia, low HDL, insulin resistance, or prediabetes, respectively, at baseline no longer had the condition at follow-up. In contrast, of individuals within the reference range at baseline, new cases at follow-up were found for 10.1%, 12.2%, 6.3%, 8.2%, and 7.6% (as above, respectively). Regression models revealed a significant association between serum 25-hydroxyvitamin D concentrations ≥100 nmol/L and reductions in many CVD risk parameters after adjustment for confounding variables. These findings suggest that a preventive approach to health and wellness focused on nutrients, optimal serum 25-hydroxyvitamin D concentrations, and lifestyle changes has the potential to reduce the risk of CVD.

Association between vitamin D and hypertension in people coming for health check up to a tertiary care centre in South India

INTRODUCTION

Vitamin D has many effects apart from its role in calcium metabolism and bone health. Vitamin D is derived from endogenous ultraviolet-B induced vitamin D synthesis in the skin, and the current high prevalence of vitamin D deficiency in India, can be attributed to lifestyle related low sunlight exposure. Identification of the vitamin D receptor (VDR) in almost all human cells, suggests a role in extra skeletal diseases. Studies have shown that vitamin D deficiency is an independent risk factor for hypertension.

AIM

To evaluate the association between vitamin D and hypertension in people coming for health check up to a tertiary care center in South India.

MATERIALS AND METHODS

Study was carried out as a cross sectional study in a tertiary care hospital in South India. Participants (520) were both males and females (337 males and 183 females), between the age group of 20-60 years attending the comprehensive health check up clinic of our hospital.

STATISTICAL ANALYSIS

Statistical analysis was done using IBM SPSS statistics 20.0.

RESULTS

Severe vitamin D deficiency was highly prevalent in people with hypertension than in people without hypertension (P value <0.001).

CONCLUSION

Since India is a tropical country, till recently it was believed that vitamin D deficiency and its ill effects are uncommon. But it was found that, vitamin D deficiency was highly prevalent in people with hypertension in South India, emphasizing the need of early vitamin D supplementation. Therefore, to reduce cardiovascular morbidity, early identification of vitamin D deficiency and appropriate vitamin D supplementation may be of primary importance in population, especially like ours, having high prevalence.

Vitamin D and Calcimimetics in Cardiovascular Disease

Cardiovascular disease has earned its place as one of the leading noncommunicable diseases that has become a modern-day global epidemic. The increasing incidence and prevalence of chronic kidney disease (CKD) has added to this enormous burden, given that CKD is now recognized as an established risk factor for accelerated cardiovascular disease. In fact, cardiovascular disease remains the leading cause of death in the CKD population, with significant prognostic implications. Alterations in vitamin D levels as renal function declines has been linked invariably to the development of cardiovascular disease beyond a mere epiphenomenon, and has become an important focus in recent years in our search for new therapies. Another compound, cinacalcet, which belongs to the calcimimetic class of agents, also has taken center stage over the past few years as a potential cardiovasculoprotective agent. However, given limited well-designed randomized trials to inform us, our clinical practice for the management of cardiovascular disease in CKD has not been adequately refined. This article considers the biological mechanisms, regulation, and current experimental, clinical, and trial data available to help guide the therapeutic use of vitamin D and calcimimetics in the setting of CKD and cardiovascular disease.

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.

Reduction of Some Atherogenic Indices in Patients with Non-Alcoholic Fatty Liver by Vitamin D and Calcium Co-Supplementation: A Double Blind Randomized Controlled Clinical Trial

The role of non-alcoholic fatty liver disease (NAFLD) as a potential independent cardiovascular disease (CVD) risk factor has recently gained considerable attention because CVD is the common cause of death in NAFLD patients. We aimed to estimate the effects of vitamin D supplementation alone or in combination with calcium on atherogenic indices, liver function tests, and grade of disease in patients with NAFLD. One-hundred twenty NAFLD patients were randomized in a double-blind, placebo-controlled clinical trial as follows: D (1000 IU vitamin D), CaD (500 mg as calcium carbonate plus 1000 IU vitamin D) or P (placebo), once daily with meals over 12 weeks. Adjusted for all the baseline measures, reduction in serum ALT, AST, LDL-C/HDL-C, TC/HDL-C, and non-HDL-C were significantly higher in the CaD compared with the P group (p < 0.001, p = 0.03, p < 0.001, p < 0.001, p < 0.001 and p < 0.001, respectively). Also, mean difference of serum ALT, LDL-C/HDL-C, TC/HDL-C, and TG/HDL-C were significantly higher in the CaD than D group (p < 0.001, p = 0.006, p < 0.001 and p = 0.03, respectively). Serum non-HDL-C was marginally decreased in the CaD compared with the D group (p = 0.06). With considering the BMI changes as covariate, reduction in the grade of fatty liver was significantly higher in the CaD and D groups than the P (p < 0.001). The present study suggests that supplemental calcium combined with vitamin D, but not vitamin D alone, may reduce serum atherogenic indices, liver function tests, and grade of disease in patients with NAFLD.

Vitamin D and Metabolic Diseases: Growing Roles of Vitamin D

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

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.

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.

Non-musculoskeletal benefits of vitamin D

The aim of this study is to determine and critically evaluate the plausible relationships of vitamin D with extra-skeletal tissues in humans. Severe vitamin D deficiency results in rickets in children and osteomalacia in adults; these beneficial effects in the musculoskeletal system and certain physiological functions are well understood. Nevertheless, mounting reports support additional beneficial effects of vitamin D, outside the musculoskeletal system. This review explores the recent advances in knowledge about the non-skeletal effects of vitamin D. Peer-reviewed papers were extracted from research databases using key words, to assess correlations between vitamin D and extra-skeletal diseases and conditions. As per the guidelines of the Preferred Reporting Items for Systematic Reviews (PRISMA); general interpretations of results are included; taking into consideration the broader evidence and implications. This review summarizes current knowledge of the effects of vitamin D status on extra-skeletal tissues with special attention given to relationships between vitamin D status and various diseases commonly affecting adults; the effects of intervention with vitamin D and exposure to sunlight. Evidence suggests that vitamin D facilitates the regulation of blood pressure; and cardiac; endothelial; and smooth muscle cell functions; playing an important role in cardiovascular protection. In addition; 1,25(OH)₂D improves immunity; subdues inflammation; and reduces the incidence and severity of common cancers; autoimmune diseases and infectious diseases. Almost all adequately powered; epidemiological and biological studies that use; adequate doses of vitamin D supplementation in D-deficient populations have reported favorable outcomes. These studies have concluded that optimizing 25(OH)D status improves the functionality of bodily systems; reduces comorbidities; improves the quality of life; and increases survival. Although accumulating evidence supports biological associations of vitamin D sufficiency with improved physical and mental functions; no definitive evidence exists from well-designed; statistically powered; randomized controlled clinical trials. Nevertheless, most studies point to significant protective effects of vitamin D in humans when the minimum 25(OH)D serum level exceeds 30ng/mL and is maintained throughout the year.

Effects of high-dose parenteral vitamin D therapy on lipid profile and blood pressure in patients with diabetic nephropathy: A randomized double-blind clinical trial

AIMS

Aim of this study was to determine the effect of high dose vitamin D given to patients with early diabetic renal disease on systolic and diastolic blood pressure, total cholesterol (TC), low-density lipoproteins (LDL), triglycerides (TG) and high density lipoproteins (HDL) in a randomized controlled trial MATERIALS AND METHOD: Patients with early diabetic nephropathy were recruited. Selected patients were allocated to two groups by Block randomization method. Treatment group received 50,000 IU of vitamin D3 intramuscularly and the control group was given an equal volume of distilled water (0.25mL) monthly for six months. Blood and urine were collected at the baseline for biochemical analyses and blood pressure was measured. After six months all the measurements done at the baseline were repeated.

RESULTS

Of 155 patients invited, 85 were randomly assigned to two groups. No significant differences were found between treatment and control groups at the baseline. Vitamin D therapy significantly reduced DBP, total cholesterol and LDL but the between group differences were not significant. There was an increase in HDL cholesterol level in the treatment group while there was no change in the control group Between groups difference was significant (P=<0.001).

CONCLUSIONS

There was a significant improvement of serum HDL level with six months therapy of high dose vitamin D in patients with early diabetic nephropathy.

The Association between Serum 25(OH)D Status and Blood Pressure in Participants of a Community-Based Program Taking Vitamin D Supplements

Background: Vitamin D deficiency is a risk factor for hypertension. Methods: We assessed 8155 participants in a community-based program to investigate the association between serum 25-hydroxyvitamin D (25(OH)D) status and blood pressure (BP) and the influence of vitamin D supplementation on hypertension. Participants were provided vitamin D supplements to reach a target serum 25(OH)D > 100 nmol/L. A nested case-control study was conducted to examine the effect of achieving physiological vitamin D status in those who were hypertensive and not taking BP-lowering medication, and hypertensive participants that initiated BP-lowering medication after program entry. Results: At baseline, 592 participants (7.3%) were hypertensive; of those, 71% were no longer hypertensive at follow-up (12 ± 3 months later). There was a significant negative association between BP and serum 25(OH)D level (systolic BP: coefficient = −0.07, p < 0.001; diastolic BP: coefficient = −0.1, p < 0.001). Reduced mean systolic (−18 vs. −14 mmHg) and diastolic (−12 vs. −12 mmHg) BP, pulse pressure (−5 vs. −1 mmHg) and mean arterial pressure (−14 vs. −13 mmHg) were not significantly different between hypertensive participants who did and did not take BP-lowering medication. Conclusion: Improved serum 25(OH)D concentrations in hypertensive individuals who were vitamin D insufficient were associated with improved control of systolic and diastolic BP.

The Role of Toll-Like Receptors and Vitamin D in Cardiovascular Diseases-A Review

Cardiovascular diseases are the leading cause of mortality worldwide. Therefore, a better understanding of their pathomechanisms and the subsequent implementation of optimal prophylactic and therapeutic strategies are of utmost importance. A growing body of evidence states that low-grade inflammation is a common feature for most of the cardiovascular diseases in which the contributing factors are the activation of toll-like receptors (TLRs) and vitamin D deficiency. In this article, available data concerning the association of cardiovascular diseases with TLRs and vitamin D status are reviewed, followed by a discussion of new possible approaches to cardiovascular disease management.

Vitamin D and Hypertension

Vitamin D has the pleiotropic effects in multiple organ systems, and vitamin D deficiency was suggested to be associated with high blood pressure according to previous reports. Several interventional studies have examined the effect of vitamin D supplementation on high blood pressure patients, but the results have been inconsistent. In this article, we examined the literature that have proposed a mechanism involving vitamin D in the regulation of blood pressure and review previous observational and interventional studies that have shown the relationship between vitamin D and hypertension among various populations.

Effects of calcium plus vitamin D supplementation on blood pressure: a systematic review and meta-analysis of randomized controlled trials

The effect of calcium or vitamin D supplement on blood pressure (BP) has been explored in previous meta-analyses, but the results are conflicting. The combined efficacy of calcium and vitamin D on BP has not been systematically assessed. Thus, we conducted a meta-analysis of randomized controlled trials (RCTs) to explore the effect of calcium plus vitamin D (CaD) supplementation on changes of systolic blood pressure (SBP) and diastolic blood pressure among male and female participants (with and without diagnosed hypertension) aged 18 years or older. The PubMed, the Embase and the Cochrane Central Register of controlled trials were searched. A random effects model was used to calculate the pooled weighted mean differences (WMDs) with 95% confidence intervals (CIs) for the continuous outcome data. Cochrane Collaboration tool was used to assess the study quality of each trial. We further performed subgroup analysis and meta-regression by ethnicity, gender, age, health status, supplement dose, co-interventions, supplement duration and quality assessment. Eight RCTs involving 36 806 participants were assessed. The follow-up time ranged from 15 weeks to a maximum of 7 years. No meaningful effect on daytime office BP was detected in the present study, with evidence of significant heterogeneity. Subgroup analysis by gender indicated some evidence of elevated SBP in male participants, and the WMD (95% CI) was 1.49 mm Hg (1.03, 1.95). Further high-quality research is still warranted to confirm the magnitude of the effect of CaD supplementation on the changes of BP among participants with different ethnicity, gender, health status and CaD supplements.

Long-term exposure to residential ambient fine and coarse particulate matter and incident hypertension in post-menopausal women

BACKGROUND

Long-term exposure to ambient particulate matter (PM) has been previously linked with higher risk of cardiovascular events. This association may be mediated, at least partly, by increasing the risk of incident hypertension, a key determinant of cardiovascular risk. However, whether long-term exposure to PM is associated with incident hypertension remains unclear.

METHODS

Using national geostatistical models incorporating geographic covariates and spatial smoothing, we estimated annual average concentrations of residential fine (PM2.5), respirable (PM10), and course (PM10-2.5) fractions of particulate matter among 44,255 post-menopausal women free of hypertension enrolled in the Women's Health Initiative (WHI) clinical trials. We used time-varying Cox proportional hazards models to evaluate the association between long-term average residential pollutant concentrations and incident hypertension, adjusting for potential confounding by sociodemographic factors, medical history, neighborhood socioeconomic measures, WHI study clinical site, clinical trial, and randomization arm.

RESULTS

During 298,383 person-years of follow-up, 14,511 participants developed incident hypertension. The adjusted hazard ratios per interquartile range (IQR) increase in PM2.5, PM10, and PM10-2.5 were 1.13 (95% CI: 1.08, 1.17), 1.06 (1.03, 1.10), and 1.01 (95% CI: 0.97, 1.04), respectively. Statistically significant concentration-response relationships were identified for PM2.5 and PM10 fractions. The association between PM2.5 and hypertension was more pronounced among non-white participants and those residing in the Northeastern United States.

CONCLUSIONS

In this cohort of post-menopausal women, ambient fine and respirable particulate matter exposures were associated with higher incidence rates of hypertension. These results suggest that particulate matter may be an important modifiable risk factor for hypertension.

Long-term exposure to residential ambient fine and coarse particulate matter and incident hypertension in post-menopausal women

BACKGROUND

Long-term exposure to ambient particulate matter (PM) has been previously linked with higher risk of cardiovascular events. This association may be mediated, at least partly, by increasing the risk of incident hypertension, a key determinant of cardiovascular risk. However, whether long-term exposure to PM is associated with incident hypertension remains unclear.

METHODS

Using national geostatistical models incorporating geographic covariates and spatial smoothing, we estimated annual average concentrations of residential fine (PM_2.5), respirable (PM₁₀), and course (PM_10-2.5) fractions of particulate matter among 44,255 post-menopausal women free of hypertension enrolled in the Women's Health Initiative (WHI) clinical trials. We used time-varying Cox proportional hazards models to evaluate the association between long-term average residential pollutant concentrations and incident hypertension, adjusting for potential confounding by sociodemographic factors, medical history, neighborhood socioeconomic measures, WHI study clinical site, clinical trial, and randomization arm.

RESULTS

During 298,383 person-years of follow-up, 14,511 participants developed incident hypertension. The adjusted hazard ratios per interquartile range (IQR) increase in PM_2.5, PM₁₀, and PM_10-2.5 were 1.13 (95% CI: 1.08, 1.17), 1.06 (1.03, 1.10), and 1.01 (95% CI: 0.97, 1.04), respectively. Statistically significant concentration-response relationships were identified for PM_2.5 and PM₁₀ fractions. The association between PM_2.5 and hypertension was more pronounced among non-white participants and those residing in the Northeastern United States.

CONCLUSIONS

In this cohort of post-menopausal women, ambient fine and respirable particulate matter exposures were associated with higher incidence rates of hypertension. These results suggest that particulate matter may be an important modifiable risk factor for hypertension.

25-Hydroxyvitamin D and blood pressure: a plateau effect in adults with African ancestry living at different latitudes

OBJECTIVE

This study examined the association of 25-hydroxyvitamin D [25(OH)D] levels and blood pressure above and below 25(OH)D levels of 20 ng/ml in young adults with African ancestry.

METHODS

This cross-sectional analysis utilized data from a pooled sample of 2242 adults with African ancestry from five different latitudes (403 in the United States, 474 in South Africa, 479 in Ghana, 448 in Jamaica, and 438 in Seychelles). Piecewise linear regression models with a single knot were fitted to determine above and below a 25(OH)D level of 20 ng/ml the slope of SBP and DBP while adjusting for covariates including calcium intake and site.

RESULTS

The mean age was 34.4 (6.1) years, and 46.3% were men. Mean SBP and DBP were 118.1 (15.6) and 73.2 (12.2) mmHg, respectively, and were significantly higher among the United States vs Ghana, Jamaica, and Seychelles groups (P < 0.001 for all comparisons). 25(OH)D levels were significantly lower in the United States vs all other sites (P < 0.001 for all comparisons). When 25(OH)D levels were less than 20 ng/ml, slopes of SBP [-0.33 (95% confidence interval (CI) -0.57, -0.07)] and DBP [-0.21 (95% CI -0.40, -0.02)] were negative and significantly different from zero after adjustment for covariates. In contrast, with 25(OH)D levels above 20 ng/ml, the slopes of SBP [-0.03 (95% CI -0.13, 0.06)] and DBP [-0.04 (-0.11, 0.03)] did not differ significantly from zero.

CONCLUSION

The cross-sectional association of 25(OH)D with blood pressure is strongest when 25(OH)D levels are less than 20 ng/ml in young adults with African ancestry.

Vitamin D and hypertension: Prospective study and meta-analysis

OBJECTIVES

The study sought to determine the link between vitamin D concentrations and incident hypertension in prospective study and meta-analysis.

METHODS

The study was embedded in the Kailuan Study, a population-based cohort of adults that contains underground miners. In 2012, we studied 2,456 men and women free of prevalent hypertension, age 21 to 67 at baseline. Serum 25-hydroxyvitamin D was measured from previously frozen baseline samples using ELISA (Enzyme-Linked ImmunoadSorbent Assay). We use the logistic regression analysis to estimate the odd radio (ORs) 95% confidence intervals (CIs) for 25-hydroxyvitamin D [25(OH)D] concentrations with incident hypertension. To help place our new data in context, we conducted a systemic review and meta-analysis of previous prospective reports of vitamin D and hypertension.

RESULTS

During a median follow-up of 2 years, 42.6% of the cohort (n = 1047) developed hypertension. Compared with the 25-hydroxyvitamin D >30ng/ml, 25-hydroxyvitamin D <20 ng/ml was associated with a greater hypertension risk (OR: 1.225 [95% CI: 1.010 to 1.485] p = 0.04), although the association was attenuated and not statistically significant after adjusting for potential confounders (OR: 1.092 [95% CI: 0.866 to 1.377] p = 0.456). This meta-analysis included seven prospective studies for 53,375 participants using adjusted HR founded a significant association between vitamin D deficiencies and incident hypertension (HRs = 1.235 (95% CI: 1.083 to 1.409, p = 0.002)).

CONCLUSION

Lower serum 25-hydroxyvitamin D concentrations were not associated with a greater risk of incident hypertension. More research is needed to further determine the role of 25-hydroxyvitamin D in hypertension prevention and therapy.

Physiology and Pathophysiology of the Intrarenal Renin-Angiotensin System: An Update

The renin-angiotensin system (RAS) has a pivotal role in the maintenance of extracellular volume homeostasis and blood pressure through complex mechanisms. Apart from the well known systemic RAS, occurrence of a local RAS has been documented in multiple tissues, including the kidney. A large body of recent evidence from pharmacologic and genetic studies, particularly those using various transgenic approaches to manipulate intrarenal levels of RAS components, has established the important role of intrarenal RAS in hypertension. Recent studies have also begun to unravel the molecular mechanisms that govern intrarenal RAS activity. This local system is under the control of complex regulatory networks consisting of positive regulators of (pro)renin receptor, Wnt/β-catenin signaling, and PGE₂/PGE₂ receptor EP₄ subtype, and negative regulators of Klotho, vitamin D receptor, and liver X receptors. This review highlights recent advances in defining the regulation and function of intrarenal RAS as a unique entity separate from systemic angiotensin II generation.

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.

The effect of vitamin D supplementation on hypertension in non-CKD populations: A systemic review and meta-analysis

OBJECTIVES

To investigate the vitamin D supplementation on blood pressure control by a systemic review and meta-analysis.

METHODS

Randomized controlled clinical trials were analyzed, which date from eight studies in databases including MEDLINE, EMBASE, Clinical trials, China Integrated Knowledge Resources Database and the Cochrane library.

RESULTS

Total 917 patients from eight randomized controlled trials (RCTs), treatment with vitamin D for more than 3months were analyzed. Meta-analysis showed that vitamin D supplementation slightly reduced the systolic blood pressure (SBP) by 1.964mmHg (95% CI, 0.362-3.566; P=0.016), but not lowered diastolic blood pressure (SMD: -0.087, 95% CI, -0.208-0.033; P=0.155). Subgroup analysis also showed that sBP lowering by vitamin D supplementation was not dose-dependent. Comparison to placebo, there is also no statistical difference in SBP lowering by vitamin D supplementation.

CONCLUSIONS

This meta-analysis indicated that vitamin D is not an antihypertensive agent although it has a moderate SBP lowering effect. More RCTs are required to observe the role of vitamin D plus other antihypertensive drugs in blood pressure control, and define the optimum dose, dosing interval, and type of vitamin D to administer.

Effectiveness of Vitamin D Supplementation for Cardiovascular Health Outcomes

There is a plausible physiological theory, supported by many observational studies, that vitamin D supplementation should be effective for improving cardiovascular end points, such as blood pressure (BP), large artery stiffness, atherosclerosis, endothelial function and clinical events. However, results from randomised controlled trials (RCTs) have been inconsistent. In this review, we evaluated the evidence regarding the effectiveness of vitamin D supplementation for cardiovascular surrogate and hard clinical end points. RCTs were assessed in terms of sample size, duration of supplementation, baseline vitamin D level inclusion criteria (i.e., absence of vitamin D deficiency), dosage of vitamin D and population under investigation. Forty-five RCTs were identified. Eight RCTs with BP and 6 RCTs with large artery stiffness as the end points were found to comply with guidelines for the optimal design of clinical trials evaluating nutrient effects. Only 2 of the RCTs with an optimal design were effective in decreasing BP with vitamin D supplementation, although these were of moderate sample size (<150) and very short duration (8 weeks for both), whilst no RCT was effective in reducing large artery stiffness. Similar results were observed for atherosclerotic and endothelial function markers as end points. Only 1 RCT reported cardiovascular events as an end point and found neither increased nor decreased incident cardiovascular events over 7 years of follow-up. In conclusion, results from published RCTs indicate that vitamin D supplementation is ineffective in improving cardiovascular health among various patient populations, including in the presence or absence of vitamin D deficiency.

Effect of 1,25(OH)2D3 on transdifferentiation of rat renal tubular epithelial cells induced by high glucose

Deficiency in vitamin D and its active metabolite is a characteristic of chronic kidney diseases (CKDs). Previous studies have reported that 1α,25-dihydroxyvitamin D₃ [1,25(OH)₂D₃], the active form of vitamin D, can attenuate renal interstitial fibrosis. The present study aimed to explore the effect of 1,25(OH)₂D₃ on the transdifferentiation of NRK-52E rat renal tubular epithelial cells (RTECs) induced by high glucose, as well as the expression of vitamin D receptor (VDR) and production of angiotensin (Ang) II. Western blot and reverse transcription-quantitative polymerase chain reaction (RT-qPCR) analyses were performed to detect the protein and mRNA expression of α-smooth muscle actin (α-SMA), E-cadherin and VDR. Furthermore, the production of Ang II was analyzed by enzyme-linked immunosorbent assay (ELISA). Treatment with high glucose decreased E-cadherin and VDR, while increasing α-SMA and Ang II, and of note, these changes were attenuated by 1,25(OH)₂D₃ in a dose-dependent manner. In conclusion, the present study revealed that 1,25(OH)₂D₃ inhibits high glucose-induced transdifferentiation of rat RTECs in a dose-dependent manner, which may be associated with the downregulation of Ang II and upregulation of VDR.

Effect of vitamin D3 supplementation on blood pressure in adults: An updated meta-analysis

BACKGROUND AND AIMS

Previous randomized clinical trials (RCTs) of the effects of vitamin D3 supplementation (VD3S) on blood pressure have generated inconsistent results. We evaluated the effect of VD3S on systolic blood pressure (SBP) and diastolic blood pressure (DBP) in a meta-analysis.

DATA SYNTHESIS

Literature searches of PubMed, Scopus, Ovid, and Google scholar for publications in English were conducted up to April 2015. RCTs that assessed the effect of VD3S on SBP and DBP were selected.

CONCLUSIONS

A total of 30 RCTs with 41 arms including 4744 participants were included. The mean duration of the studies was 5.6 ± 4.0 months, and doses of VD3S varied between 200 and 12,000 IU/day. VD3S had no effect on SBP (-0.68 mmHg, 95%CI: -2.19 to 0.84), and DBP (-0.57 mmHg, 95%CI: -1.36 to 0.22). Subgroup analysis revealed that daily vitamin D3 therapy at a dose of >800 IU/day for <6 months in subjects ≥50 years old reduced both SBP and DBP (p < 0.001). In addition, VD3S showed hypotensive effects in healthy subjects and hypertensive patients, but a hypertensive effect in overweight and obese subjects. However, after excluding overweight and obese subjects, VD3S significantly reduced SBP and DBP. VD3S in combination with calcium supplementation significantly elevated SBP (3.64 mmHg, 95%CI: 3.15-4.13) and DBP (1.71 mmHg, 95%CI: 1.25-2.18). No evidence of publication bias was found. The effects of VD3S on blood pressure depend on dose of supplementation, treatment regimens, trial duration, and population subgroup. Supplementation may be beneficial at daily doses >800 IU/day for <6 months in subjects ≥50 years old.

Vitamin D: Metabolism, Molecular Mechanism of Action, and Pleiotropic Effects

1,25-Dihydroxvitamin D3 [1,25(OH)2D3] is the hormonally active form of vitamin D. The genomic mechanism of 1,25(OH)2D3 action involves the direct binding of the 1,25(OH)2D3 activated vitamin D receptor/retinoic X receptor (VDR/RXR) heterodimeric complex to specific DNA sequences. Numerous VDR co-regulatory proteins have been identified, and genome-wide studies have shown that the actions of 1,25(OH)2D3 involve regulation of gene activity at a range of locations many kilobases from the transcription start site. The structure of the liganded VDR/RXR complex was recently characterized using cryoelectron microscopy, X-ray scattering, and hydrogen deuterium exchange. These recent technological advances will result in a more complete understanding of VDR coactivator interactions, thus facilitating cell and gene specific clinical applications. Although the identification of mechanisms mediating VDR-regulated transcription has been one focus of recent research in the field, other topics of fundamental importance include the identification and functional significance of proteins involved in the metabolism of vitamin D. CYP2R1 has been identified as the most important 25-hydroxylase, and a critical role for CYP24A1 in humans was noted in studies showing that inactivating mutations in CYP24A1 are a probable cause of idiopathic infantile hypercalcemia. In addition, studies using knockout and transgenic mice have provided new insight on the physiological role of vitamin D in classical target tissues as well as evidence of extraskeletal effects of 1,25(OH)2D3 including inhibition of cancer progression, effects on the cardiovascular system, and immunomodulatory effects in certain autoimmune diseases. Some of the mechanistic findings in mouse models have also been observed in humans. The identification of similar pathways in humans could lead to the development of new therapies to prevent and treat disease.

Dissociation between Low Vitamin D Level and Hypertension in Coal Mine Workers: Evidence from the Kailuan Study

Objective The aim of this study was to evaluate the vitamin D status and the relationship between the vitamin D status and hypertension in a relatively large cohort in northern China. Methods This study was a part of the Kailuan study, consisting of 3,788 coal mine workers (including 2,532 underground workers and 1,256 surface workers) who received periodic health examinations between September 13, 2012 and December 24, 2012. Information on demographic factors, personal history and medical history were collected. The height, weight, blood pressure and serum25-hydroxyvitamin D [25(OH)D] level of each patient were measured. Results The mean 25(OH)D level in this cohort was 21.73±15.82 nmol/L. The number (%) of patients with vitamin D deficiency, insufficiency, inadequacy and sufficiency were 2,509 (66.24%), 1,051 (27.75%), 201 (5.31%) and 27 (0.71%), respectively. In all the participants, after adjusting for the age, salt intake, physical activity, smoking status, alcohol drinking status, work type, work environment, body mass index, diabetes and hyperlipidemia, the odds ratios for hypertension with 25(OH)D level ≥50, 25-50 and <25 nmol/L were 1.00 (reference), 1.44 (95%CI, 0.99-2.11) and 1.39 (95%CI, 0.97-1.99), respectively. Logistic regression models to evaluate the odds ratios and 95% CIs of hypertension for each quintile of the 25(OH)D level did not determine significant associations between the vitamin D status and hypertension. No significant associations were found in the underground workers or in the surface workers. Conclusion There was a high proportion of coal mine workers with vitamin D deficiency and insufficiency in Kailuan. However, no significant association between low vitamin D levels and hypertension was found in this cohort. Further investigations are needed to determine the relationship between vitamin D levels and hypertension.

Serum vitamin D in hypertensive patients versus healthy controls is there an association?

BACKGROUND

Both vitamin D deficiency and hypertension are prevalent in the general population. Several observations indicate an association between vitamin D deficiency and high blood pressure. The present case-control study aimed to compare serum 25-hydroxyvitamin D (25-OHD) in hypertensive patients versus healthy controls.

METHODS

One hundred patients aged 30-60 years with hypertension (HTN) and 100 healthy controls without history of hypertention were compared regarding serum 25-OHD. Blood pressure was measured using standard method and the systolic and diastolic blood pressure more than140 mmHg and 90 mmHg respectively were considered as HTN. Patients and controls with coexistent morbidities, vitamin D supplementation were excluded. The serum levels of 25-OHD, PTH and calcium were measured after obtaining a written informed consent from the patients and taking their blood pressure under standard conditions. In statistical analysis, the two groups were compared using independent t test and chi-square test using SPSS Version 18.

RESULTS

The mean age of patients and controls was comparable (53.7±6.4 vs 52.3±7.54 years, P=0.17). Serum 25-OHD in HTN was significantly higher than controls (P=0.001).

CONCLUSION

In the present study, serum 25-OHD level in hypertension was higher than controls. The results contradict with earlier studies indicating an association of HTN with vitamin D deficiency. This issue warrants further investigations in particular the follow-up of serum 25-OHD deficient and sufficient subjects with regard to the development of HTN.

Association of Serum 25-Hydroxyvitamin D and Parathyroid Hormone With Hypertension in Middle-Aged and Older Korean Adults

BACKGROUND

Previous studies have suggested that serum 25-hydroxyvitamin D [25(OH)D] and parathyroid hormone (PTH) levels are associated with hypertension. However, the associations have yet to be studied in Koreans. This study explored the relationship among serum 25(OH)D, PTH concentrations, and the presence of hypertension in middle-aged and older Korean adults using the most recent nationally representative survey data.

METHODS

A population-based, cross-sectional study was conducted with data collected from 5,260 Korean adults (aged ≥50 years) who participated in the 2010 and 2011 Korean National Health and Nutrition Examination Surveys. Hypertension was defined as a systolic blood pressure ≥140 mm Hg, diastolic blood pressure ≥90 mm Hg, or current use of antihypertensive medication.

RESULTS

The prevalence of hypertension significantly increased according to the quartiles of serum PTH levels (P < 0.0001), but not of serum 25(OH)D levels. In multivariable logistic analysis, the adjusted odds ratios (ORs) for hypertension were significantly higher among participants in the highest quartile than among those in the lowest quartile of serum PTH level, after adjusting for potential confounders (OR = 1.26, 95% confidence interval: 1.02-1.56, P = 0.03). The adjusted ORs for hypertension tended to decrease across the quartiles of serum 25(OH)D level, but the associations were not significant.

CONCLUSION

Serum 25(OH)D was not associated with the presence of hypertension, whereas serum PTH was positively associated, suggesting that serum PTH may be an independent risk factor for hypertension in middle-aged and older Korean adults.