Vitamin D deficiency among patients with pulmonary hypertension

Vitamin D as an add-on therapy to phosphodiesterase-5 inhibitor in experimental pulmonary arterial hypertension

Severe vitamin D (vitD) deficiency is a very common condition in patients with pulmonary arterial hypertension (PAH), and it is a predictor of poor prognosis. There is emerging evidence suggesting a connection between the insufficient response to phosphodiesterase-5 inhibitors (PDE5i) and vitD deficiency in patients with PAH. In the present translational study, vitD deficiency was induced in Wistar rats by exposure to vitD-free diet for 5 wk and followed by Su5416 administration and hypoxia (10%) for 3 wk, a standard experimental model of PAH. Then, rats were randomized to either 1) the PDE5i tadalafil and continuing vitD-free diet or 2) tadalafil plus a single dose of vitD and standard diet for 4 wk. VitD supplementation improved exercise capacity and right ventricular function and decreased systolic right ventricular pressure, right atrial hypertrophy, right ventricular hypertrophy, and pulmonary arterial remodeling. VitD improved the ex vivo endothelium-dependent response to acetylcholine, indicating an improvement in NO bioavailability, which also resulted in an acute ex vivo response to sildenafil. Thus, the restoration of vitD, by rescuing endothelial function and PDE5i effectiveness, significantly improved the histological, hemodynamic, and functional features of rats with PAH. VitD may be especially beneficial for PDE5i-treated patients with PAH.NEW & NOTEWORTHY Severe vitamin D deficiency is very prevalent in patients with pulmonary arterial hypertension. We show that addition of vitamin D to the standard PDE5 inhibitor tadalafil increases its therapeutic efficacy in pulmonary hypertensive rats that were deficient in vitamin D.

Pulmonary Hypertension and Anastrozole (PHANTOM): A Randomized, Double-Blind, Placebo-Controlled Trial

Rationale: Inhibition of aromatase with anastrozole reduces pulmonary hypertension in experimental models. Objectives: We aimed to determine whether anastrozole improved the 6-minute-walk distance (6MWD) at 6 months in pulmonary arterial hypertension (PAH). Methods: We performed a randomized, double-blind, placebo-controlled phase II clinical trial of anastrozole in subjects with PAH at seven centers. Eighty-four postmenopausal women with PAH and men with PAH were randomized in a 1:1 ratio to receive anastrozole 1 mg or placebo by mouth daily, stratified by sex using permuted blocks of variable sizes. All subjects and study staff were masked. The primary outcome was the change from baseline in 6MWD at 6 months. By intention-to-treat analysis, we estimated the treatment effect of anastrozole using linear regression models adjusted for sex and baseline 6MWD. Assuming 10% loss to follow-up, we anticipated having 80% power to detect a difference in the change in 6MWD of 22 meters. Measurements and Main Results: Forty-one subjects were randomized to placebo and 43 to anastrozole, and all received the allocated treatment. Three subjects in the placebo group and two in the anastrozole group discontinued the study drug. There was no significant difference in the change in 6MWD at 6 months (placebo-corrected treatment effect, -7.9 m; 95% confidence interval, -32.7 to 16.9; P = 0.53). There was no difference in adverse events between the groups. Conclusions: Anastrozole did not show a significant effect on 6MWD compared with placebo in postmenopausal women with PAH and in men with PAH. Anastrozole was safe and did not have adverse effects. Clinical trial registered with www.clincialtrials.gov (NCT03229499).

An inverse causal relationship between serum 25-hydroxyvitamin D levels and pulmonary hypertension: A two-sample Mendelian randomization study

Observational studies have confirmed that 25-hydroxyvitamin D (25(OH)D) is associated with pulmonary hypertension (PH), but the causal association between each other is unclear. Therefore, Mendelian randomization (MR) method was performed to validate the causal association between PH and serum 25(OH)D levels. The summary data for 25(OH)D and PH were from the National Human Genome Research Institute-European Bioinformatics Institute. Catalog of human genome-wide association studies and FinnGen biobank consortium. MR analysis was utilized to explore the potential causal association between PH and 25(OH)D. To evaluate this association, inverse variance weighting was considered as the primary method. Cochran's Q test, MR-Egger intercept test, and "leave-one-out" sensitivity analyses were utilized to control the pleiotropy and heterogeneity in the study. Two-sample MR analysis revealed an inverse causal relationship between 25(OH)D and PH (odds ratio: 0.376, 95% confidence interval: 0.162-0.876, p = 2.334 × 10-2). There was no significant heterogeneity and pleiotropy. The present study confirmed the inverse causal relationship between 25(OH)D and PH. This pathway may provide another treatment pathway in PH. Further studies to elucidate this pathway is indicated.

The role of vitamin D in chronic obstructive pulmonary disease with pulmonary hypertension

Hypoxia pulmonary hypertension (PH) belongs to the third major category in PH classification. Chronic obstructive pulmonary disease (COPD) is a common cause of hypoxia PH. Low serum vitamin D concentration is considered to be a possible risk factor for chronic lung disease; epidemiological studies have found that vitamin D deficiency increases pulmonary artery pressure. Therefore, this study aimed to explore the role of vitamin D levels in COPD and chronic hypoxic PH. This retrospective study selected three groups of people as research subjects, including: Group N: normal control group (people without any chronic lung disease or PH); Group C: patients with COPD, but without PH; Group C + PH: patients with COPD and PH. Vitamin D levels and pulmonary artery pressure were observed in the three groups. Vitamin D levels of the three groups showed statistical differences in every pairwise comparison; the vitamin D level of Group C (20.27 ng/mL) was lower than Group N (23.48 ng/mL), Group C + PH was the lowest (14.92 ng/mL). The levels of vitamin D in the three groups in this study were generally low. Vitamin D is negatively correlated with pulmonary artery systolic blood pressure. Low vitamin D levels may have a certain relationship with the occurrence and development of COPD. Further reductions in vitamin D levels may influence the development of PH in COPD.

Study of left ventricular systolic dysfunction, left ventricular diastolic dysfunction and pulmonary hypertension in CKD 3b-5ND patients-A single centre cross-sectional study

INTRODUCTION

Cardiovascular diseases are associated with increased morbidity and mortality among CKD (chronic kidney disease) population. Recent studies have found increasing prevalence of PH (pulmonary hypertension) in CKD population. Present study was done to determine prevalence and predictors of LV (left ventricular) systolic dysfunction, LVDD (left ventricular diastolic dysfunction) and PH in CKD 3b-5ND (non-dialysis) patients.

METHODS

A cross sectional observational study was done from Jan/2020 to April/2021. CKD 3b-5ND patients aged ≥15 yrs were included. Transthoracic 2D (2 dimensional) echocardiography was done in all patients. PH was defined as if PASP (pulmonary artery systolic pressure) value above 35mm Hg, LV systolic dysfunction was defined as LVEF (left ventricular ejection fraction)≤50% and LVDD as E/e' ratio >14 respectively. Multivariate logistic regression model was done to determine the predictors.

RESULTS

A total of 378 patients were included in the study with 103 in stage 3b, 175 in stage 4 and 100 patients in stage 5ND. Prevalence of PH was 12.2%, LV systolic dysfunction was 15.6% and LVDD was 43.65%. Predictors of PH were duration of CKD, haemoglobin, serum 25-OH vitamin D, serum iPTH (intact parathyroid hormone) and serum albumin. Predictors of LVDD were duration of CKD and presence of arterial hypertension. Predictors of LV systolic dysfunction were eGFR (estimated glomerular filtration rate), duration of CKD, serum albumin and urine protein.

CONCLUSION

In our study of 378 CKD 3b-5ND patients prevalence of PH was 12.2%, LV systolic dysfunction was 15.6% and LVDD was 43.65%.

Understanding the Role of Vitamin D in Heart Failure

Vitamin D is now believed to have a significant role in cardiac signal transduction and regulation of gene expression, and thus influences normal cardiomyocyte function. It has been reported to provide cardioprotection through its anti-inflammatory, anti-apoptotic and anti-fibrotic actions; and to prevent cardiac remodeling, Ca 2 + -handling defects, and abnormal electrophysiological patterns. A vitamin D deficient state has been associated in the pathogenesis of heart failure; however, while many clinical studies report a benefit of vitamin D to heart function, other clinical studies are inconsistent with these findings. These uncertainties have led to a discord in the recommendation of vitamin D supplementation for the treatment of heart failure or as a preventive agent in patients deemed to be at risk for cardiac dysfunction. Accordingly, this article is intended to describe some of the mechanisms/sites of action of vitamin D in different animal models of heart failure, as well as to review the clinical observations and challenges in the interpretation and understanding of the clinical relevance of vitamin D in relation to heart function.

Differential effect of basal vitamin D status in monocrotaline induced pulmonary arterial hypertension in normal and vitamin D deficient rats: Possible involvement of eNOS/TGF-β/α-SMA signaling pathways

Vitamin D deficiency is common and linked to poor prognosis in pulmonary arterial hypertension (PAH). We investigated the differential effect of basal vitamin D levels in monocrotaline (MCT) induced PAH in normal and vitamin D deficient (VDD) rats. Rats were fed a VDD diet and exposed to filtered fluorescent light to deplete vitamin D. Normal rats were pretreated with vitamin D 100 IU/d and treated with vitamin D 100 and 200 IU/d, while VDD rats received vitamin D 100 IU/d. Vitamin D receptor (VDR) silencing was done in human umbilical vein endothelial cells (HUVECs) using VDR siRNA. Calcitriol (50 nM/mL) was added to human pulmonary artery smooth muscle cells (HPASMCs) and HUVECs before and after the exposure to TGF-β (10 ng/mL). Vitamin D 100 IU/d pretreatment in normal rats up-regulated the expression of eNOS and inhibited endothelial to mesenchymal transition significantly and maximally. Vitamin D 100 IU/d treatment in VDD rats was comparable to vitamin D 200 IU/d treated normal rats. These effects were significantly attenuated by L-NAME (20 mg/kg), a potent eNOS inhibitor. Exposure to TGF- β significantly reduced the expression of eNOS and increased the mesenchymal marker expression in normal and VDR-silenced HUVECs and HPASMCs, which were averted by treatment and maximally inhibited by pretreatment with calcitriol (50 nM). To conclude, this study provided novel evidence suggesting the beneficial role of higher basal vitamin D levels, which are inversely linked with PAH severity.

Vitamin D Levels and Cardiopulmonary Status in Infants with Acute Bronchiolitis

BACKGROUND

To assess association of Vitamin D deficiency with cardiac and pulmonary status in infants with acute bronchiolitis.

METHODS

Infants hospitalized with acute bronchiolitis were enrolled and classified as those with serum 25 hydroxyvitamin D (25-OHD) below or equal and above 20 ng/mL. The primary outcomes were cardiopulmonary involvement defined by elevation of NT-ProBNP, alteration of echocardiographic parameters and respiratory support requirements. The secondary outcomes were the need for PICU admission and duration of hospitalization.

RESULTS

Ninety two (50 males) infants with median (IQR) age 1 (0.5 - 3) months were included with median (IQR) serum 25 - OHD level 27.4 (11.4 - 40.3) ng/mL. Forty-three (47%) patients had serum below 20 ng/mL with left ventricle dysfunction (P=0.008), right ventricle dysfunction (P=0.008) and pulmonary hypertension (P=0.007) on echocardiography than those with serum 25 - OHD > 20 ng/mL. The median (IQR) serum NT - ProBNP levels were higher in those with low 25 - OHD levels than normal 25 - OHD levels [2232.2 (461.4 - 4313.3) and 830.4 (312.7 - 2579.5)], respectively; P=0.003. Low 25-OHD levels were associated with increased risk for PICU admission (OR 3.9 (95% CI 1.5-10.1); P=0.004), higher rates of non-invasive ventilation, (P= 0.048), mechanical ventilation (P=0.005), and longer duration of hospitalization (P=0.015).

CONCLUSION

Low serum vitamin D level was associated with clinical severity and impaired cardiac and pulmonary status in infants with acute bronchiolitis.

Restoration of Vitamin D Levels Improves Endothelial Function and Increases TASK-Like K+ Currents in Pulmonary Arterial Hypertension Associated with Vitamin D Deficiency

Background: Vitamin D (vitD) deficiency is highly prevalent in patients with pulmonary arterial hypertension (PAH). Moreover, PAH-patients with lower levels of vitD have worse prognosis. We hypothesize that recovering optimal levels of vitD in an animal model of PAH previously depleted of vitD improves the hemodynamics, the endothelial dysfunction and the ionic remodeling. Methods: Male Wistar rats were fed a vitD-free diet for five weeks and then received a single dose of Su5416 (20 mg/Kg) and were exposed to vitD-free diet and chronic hypoxia (10% O₂) for three weeks to induce PAH. Following this, vitD deficient rats with PAH were housed in room air and randomly divided into two groups: (a) continued on vitD-free diet or (b) received an oral dose of 100,000 IU/Kg of vitD plus standard diet for three weeks. Hemodynamics, pulmonary vascular remodeling, pulmonary arterial contractility, and K⁺ currents were analyzed. Results: Recovering optimal levels of vitD improved endothelial function, measured by an increase in the endothelium-dependent vasodilator response to acetylcholine. It also increased the activity of TASK-1 potassium channels. However, vitD supplementation did not reduce pulmonary pressure and did not ameliorate pulmonary vascular remodeling and right ventricle hypertrophy. Conclusions: Altogether, these data suggest that in animals with PAH and severe deficit of vitD, restoring vitD levels to an optimal range partially improves some pathophysiological features of PAH.

Vitamin D improves pulmonary function in a rat model for congenital diaphragmatic hernia

A congenital diaphragmatic hernia (CDH) is an anomaly caused by defects in the diaphragm; the resulting limited thorax cavity in turn restricts lung growth (pulmonary hypoplasia). This condition is related to pulmonary hypertension. Despite advances in neonatal CDH therapy, the mortality for severe pulmonary hypoplasia remains high. Therefore, it is essential to establish prenatal therapeutic interventions. Vitamin D was reported to have beneficial effects on adult pulmonary hypertension. This study aims to evaluate the efficacy of prenatal vitamin D administration for CDH. First, serum 25-hydroxyvitamin D [25(OH)D] levels in umbilical cord blood were evaluated among CDH newborns. Second, Sprague Dawley rat CDH models were exposed to nitrofen on embryo day 9 (E9). Randomly selected rats in the nitrofen-treated group were infused with calcitriol from E9 to E21. Samples from CDH pups diagnosed after birth were used for lung weight measurements, blood gas analysis, and immunohistochemical analysis. Third, microarray analysis was performed to examine the effect of vitamin D on gene expression profiles in CDH pulmonary arterial tissues. Serum 25(OH)D levels in the umbilical cord blood of newborns who did not survive were significantly lower than those who were successfully discharged. Prenatal vitamin D showed no significant effect on CDH incidence or lung weight but attenuated alveolarization and pulmonary artery remodeling accompanied the improved blood gas parameters. Vitamin D inhibited several gene expression pathways in the pulmonary arteries of CDH rats. Our results suggest that prenatal vitamin D administration attenuates pulmonary vascular remodeling by influencing several gene pathways in CDH.

Role of Vitamin D Supplementation in Heart Failure Patients With Vitamin D Deficiency and Its Effects on Clinical Outcomes: A Literature Review

Vitamin D deficiency has become a global pandemic affecting approximately one billion people worldwide. Much attention has been paid to the association of low serum 25-hydroxyvitamin D (25(OH)D) levels and various chronic diseases, especially heart failure (HF). A clear role of vitamin D deficiency has been established, with increased mortality and morbidity in heart failures. However, previous randomized control trials have failed to show improvement in clinical outcomes with calciferol supplementation in these patients. Therefore, it is still unclear whether calciferol therapy can be added to the standard care in congestive heart failure (CHF) patients with deficiency. Hence, to evaluate the role of vitamin D supplementation in CHF patients with low serum 25(OH)D, we conducted an extensive search in the PubMed and Google Scholar databases using various combinations of keywords. All potentially eligible studies that evaluated the effects of vitamin D supplementation on clinical outcomes in HF patients were retrieved and extensively studied. We also checked the references of all eligible studies to identify additional relevant publications. In this study, we reviewed various mechanisms of vitamin D affecting the cardiovascular system and examined the impact of deficiency on heart failures in terms of mortality and hospitalizations. In conclusion, vitamin D supplementation has failed to improve the clinical outcomes in HF patients. The possible long-term benefits of supplementation cannot be excluded. Therefore, for future clinical trials, we recommend considering large sample sizes, longer follow-up durations, along with optimal dosage and appropriate dosing frequency.

Total, Bioavailable, and Free Vitamin D Levels and Their Prognostic Value in Pulmonary Arterial Hypertension

Introduction: Epidemiological studies suggest a relationship between vitamin D deficiency and cardiovascular and respiratory diseases. However, whether total, bioavailable, and/or free vitamin D levels have a prognostic role in pulmonary arterial hypertension (PAH) is unknown. We aimed to determine total, bioavailable, and free 25-hydroxy-vitamin D (25(OH)vitD) plasma levels and their prognostic value in PAH patients. Methods: In total, 67 samples of plasma from Spanish patients with idiopathic, heritable, or drug-induced PAH were obtained from the Spanish PH Biobank and compared to a cohort of 100 healthy subjects. Clinical parameters were obtained from the Spanish Registry of PAH (REHAP). Results: Seventy percent of PAH patients had severe vitamin D deficiency (total 25(OH)vitD < 10 ng/mL) and secondary hyperparathyroidism. PAH patients with total 25(OH)vitD plasma above the median of this cohort (7.17 ng/mL) had better functional class and higher 6-min walking distance and TAPSE (tricuspid annular plane systolic excursion). The main outcome measure of survival was significantly increased in these patients (age-adjusted hazard ratio: 5.40 (95% confidence interval: 2.88 to 10.12)). Vitamin D-binding protein (DBP) and albumin plasma levels were downregulated in PAH. Bioavailable 25(OH)vitD was decreased in PAH patients compared to the control cohort. Lower levels of bioavailable 25(OH)vitD (<0.91 ng/mL) were associated with more advanced functional class, lower exercise capacity, and higher risk of mortality. Free 25(OH)vitD did not change in PAH; however, lower free 25(OH)vitD (<1.53 pg/mL) values were also associated with high risk of mortality. Conclusions: Vitamin D deficiency is highly prevalent in PAH, and low levels of total 25(OH)vitD were associated with poor prognosis.