Assessment of 25-Hydroxyvitamin D Levels in Patients with Resistant Hypertension

Vitamin D: The Missing Nutrient Behind the Two Deadly Pandemics, COVID-19 and Cardiovascular Diseases

The coronavirus (COVID-19) pandemic is claiming millions of lives and creating an additional burden on health care, which is already affected by the rise of non-communicable diseases (NCDs). The scientific community, on the other side, is enormously engaged with studies to best identify the characteristics of the virus and minimize its effect while supporting the fight to contain NCDs, mainly cardiovascular diseases (CVDs), which are contributing hugely to the global death toll. Hence, the roles of vitamin D in COVID-19 immunity and cardiovascular health are gaining traction recently. 

This literature review will mainly focus on summarizing pertinent studies and scientific publications which highlight the association of vitamin D levels with the various outcomes of COVID-19 and CVDs. It will also address how low vitamin D correlates with the epidemiology of CVDs and the inflammatory mechanisms attributed to COVID-19 severity. We believe that our review may open up hindsight perspectives and further discussions among the physicians in tapping the potential of vitamin D supplementation to tackle the morbidity, mortality, and health care cost of the two deadly diseases, COVID-19 and CVDs. 

Relationship between the prognostic nutritional index and resistant hypertension in patients with essential hypertension

OBJECTIVES

Immune system activation plays a role in resistant hypertension (RHTN) pathogenesis. The clinical effect of the prognostic nutritional index (PNI) on patients with RHTN remains unclear. The aim of this study investigated the possible correlation between PNI and RHTN.

METHODS

In this cross-sectional study, we enrolled 180 adult subjects. In patients were classified into three groups according to their office and ambulatory blood pressure measurements (ABPM): RHTN (n = 60), controlled hypertension (CHTN, n = 60), and normotension-control (NT-C, n = 60). RHTN was defined as BP ≥140/90 mm Hg while taking ≥3 antihypertensive medications or BP <140/90 mm Hg while taking ≥4 medications. The PNI was calculated from the 10 x serum albumin (g/dL) + 0.005 x total lymphocyte count (/μL) formula.

RESULTS

Office and ABPM were significantly higher in patients with RHTN. Patients in the RHTN (46.1 ± 5.3) had significantly lower PNI than that in the CHTN (54.9 ± 6.7) (P = .032), and PNIs of both hypertensive groups were significantly lower than the NT-C group (P = .019, for both). The ROC curve analysis performed to assess the predictive value of PNI for RHTN and using 50.9 optimal cutoff value of PNI for RHTN gave a sensitivity of 77% and a specificity of 68.5% (AUC = 0.73, 95% CI 0.69-0.96).Multivariate analysis indicated diabetes, 24-h ABPM SBP, CRP, pill burden, and PNI (<51.6) as independent predictors of RHTN.

CONCLUSION

This study showed that the level of PNI was significantly lower in patients with RHTN compared to patients with CHTN. PNI is independently related to RHTN.

Relationship between 25-hydroxyvitamin D and microalbuminuria in patients with newly diagnosed essential hypertension

Purpose: Vitamin D deficiency is known that associated with hypertension. Microalbuminuria (MAU) is associated with increased cardiovascular morbidity and mortality. This study aimed to evaluate the relationship between 25-hydroxyvitamin D (25(OH)D) and MAU in newly diagnosed essential hypertension (NDEH) patients. Methods: A total of 116 patients with a diagnosis of NDEH were enrolled in the study. The diagnosis of hypertension was based on ABPM. Patients were divided into 2 groups according to 25(OH)D levels: Group 1: (25(OH)D)>20 ng/mL was defined as Vitamin D sufficiently (VDS), while Group 2: (25(OH)D)<20 ng/mL was defined Vitamin D deficiently (VDD). The relationship between 25(OH)D and MAU was analyzed. The results were analyzed using the SPSS program version 21. Results: The mean age of the patients was 58.4 ± 14.7 years and 60 (51.7%) of them were female. The prevalence of MAU was 18.9% and Vitamin D deficiency was 61.2% in NDEH. Linear regression analysis showed that 25(OH)D was independently related to MAU [β 0.643, 95% confidence interval 1.173-1.631, p = .011]. Besides, male gender, C-reactive protein, non-dipper hypertension, and diastolic blood pressure were independent risk factors associated with MAU in the multivariate analysis (p < .05). Conclusion: Vitamin D deficiency is highly prevalent in NDEH patients. This study showed that the level of microalbuminuria was significantly higher in patients with 25(OH)D deficiency compared to patients with normal 25(OH)D levels. Vitamin D deficiency is independently related to microalbuminuria in NDEH.

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

INTRODUCTION

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

METHODS

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

RESULTS

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

CONCLUSION

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

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

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

Association of plasma vitamin D status with lifestyle patterns and ambulatory blood pressure monitoring parameters in patients with type 2 diabetes and hypertension

AIMS

To evaluate nutritional and metabolic parameters associated with vitamin D status and blood pressure (BP) in type 2 diabetes and hypertensive patients.

METHODS

BP evaluated by office and 24-h ambulatory BP monitoring (ABPM). Physical activity was evaluated by daily step count, body composition by DXA, and diet by a food frequency questionnaire.

RESULTS

116 patients were evaluated and median 25-hydroxyvitamin D level was 21 (16-27) ng/ml; 43% deficient (<20 ng/ml). Vitamin D deficiency was associated with higher systolic ABPM (136 ± 10 vs. 130 ± 13 mmHg; P = 0.01) and daytime ABPM (138 ± 11 vs. 133 ± 13 mmHg; P = 0.02), lower step counts (4400 [2700-6600] vs. 6400 [4700-8100] steps/day), lower urinary calcium (47 [32-141] vs. 89 [68-152] mEq), and higher fat mass (31 ± 8 vs. 27 ± 6.5 kg). Milk intake (37 vs. 64%; P = 0.009) and fish (31 vs. 69%; P < 0.001) were lower in deficients. On multivariate analysis, adjusted for fat mass and colder seasons, <5000 steps/day (OR = 3.30; 95%CI 1.34-8.12), no milk/fish intake (OR = 6.56; 95%CI 2.52-17.17), and both (OR = 7.24; 95%CI 2.19-23.90) remained associated with vitamin D deficiency.

CONCLUSIONS

Vitamin D deficiency was highly prevalent in patients with hypertension and type 2 diabetes and associated with higher systolic ABPM (daytime and 24-h), less physical activity, and no milk or fish intake.

25-hydroxyvitamin D Levels was not Associated with Blood Pressure and Arterial Stiffness in Patients with Chronic Kidney Disease

Background

We investigated the effect of vitamin D deficiency on cardiovascular risk profiles in an Asian population with chronic kidney disease (CKD).

Methods

A total of 210 participants (62 non-dialysis CKD patients and 148 hemodialysis [HD] patients) were enrolled between December 2009 and February 2010. Vitamin D deficiency was determined using the serum 25-hydroxyvitamin D [25(OH)D] concentration. Blood pressure and arterial stiffness were measured. Subjects were divided into groups according to 25(OH)D concentration based on a cut-off of 13.5 ng/mL in non-dialysis CKD patients and 11.3 ng/mL in HD patients.

Results

The mean age was 61.7±12.3 years in non-dialysis CKD patients and 57.0±12.7 years in HD patients. In the non-dialysis CKD group, mean estimated glomerular filtration rate (eGFR) was 29.7±15.4 mL/min/1.73 m². Mean 25(OH)D concentration was 13.6±7.8 ng/mL in non-dialysis CKD patients and 11.3±6.7 ng/mL in HD patients. More than half of the subjects had vitamin D deficiency (67.6% in non-dialysis CKD patients and 80.4% in HD patients). There were no significant differences in systolic blood pressure, pulse pressure, and arterial stiffness between higher and lower 25(OH)D groups among non-dialysis CKD and HD patients. Multivariate analysis revealed that female sex (odds ratio [OR]: 5.890; 95% confidence interval [CI]: 2.597–13.387; p<0.001) and presence of diabetes (OR: 2.434; 95% CI: 1.103–5.370; p=0.028) were significantly associated with lower serum 25(OH)D levels in HD patients.

Conclusion

The prevalence of vitamin D deficiency was high in both nondialysis CKD patients and HD patients. Serum 25(OH)D concentration was not a significant factor associated with blood pressure and arterial stiffness among non-dialysis CKD and HD patients.

Visfatin levels are increased in patients with resistant hypertension and are correlated with left ventricular hypertrophy

OBJECTIVE

The aim of this study was to investigate the possible correlation of serum visfatin levels with resistant hypertension (RHT).

PATIENTS AND METHODS

Patients who had undergone ambulatory blood pressure measurements (ABPM) during the outpatient controls were prospectively recruited. Seventy-one patients with RHT and 94 patients with controlled hypertension (CHT) were included in the study. RHT was defined as 'uncontrolled blood pressure (BP) despite using three antihypertensive agents including a diuretic or need of four or more drugs to control BP'. The demographic properties, medications used, and laboratory parameters including visfatin levels were recorded.

RESULTS

In the RHT group, left ventricular mass index was significantly higher compared with the CHT group (108.13±26.86 vs. 89.46±24.09 g/m, P<0.01). High-sensitivity C-reactive protein and visfatin levels were significantly higher in the RHT group [4.0 (5.2) vs. 2.3 (3.0) mg/l, P<0.01, and 12.87±4.98 vs. 9.46±4.69 ng/ml, P<0.01, respectively] compared with the CHT group. In the multivariate linear regression model, visfatin level remained as an independent predictor for office systolic BP [B: 2.07, 95% confidence interval (CI): 1.17-2.98, P<0.01]; office diastolic BP (B: 0.71, 95% CI: 0.27-1.16, P<0.01); mean 24-h systolic ABPM (B: 1.46, 95% CI: 0.79-2.13, P<0.01); and mean 24-h diastolic ABPM (B: 0.88, 95% CI: 0.42-1.34, P<0.01) and was also correlated independently with left ventricular mass index (B: 3.13, 95% CI: 2.58-3.99, P<0.01).

CONCLUSION

In this cohort of RHT patients diagnosed with ABPM, we have found an independent correlation between higher visfatin levels and the presence of RHT and left ventricular hypertrophy.

The Value of Frontal Planar QRS-T Angle in Patients without Angiographically Apparent Atherosclerosis

OBJECTIVE

The present study was undertaken to investigate the prognostic value of the frontal planar QRS-T angle in patients without angiographically apparent coronary atherosclerosis.

SUBJECTS AND METHODS

Three hundred and seven patients with normal coronary arteries on coronary angiography were included. The absolute difference between the frontal QRS- and T-wave axes was defined as the frontal planar QRS-T angle, and patients were divided into 3 subgroups based on the frontal planar QRS-T angle (<45, 45-90, and >90°). Demographic, clinical, laboratory, and angiographic data were compared between groups. Based on the regression analysis results, patients were recategorized into 4 groups according to their luminal calibers of left main coronary artery (LMCA) and history of hypertension (HT) (nonhypertensive LMCA ≤4.13 mm, nonhypertensive LMCA >4.13 mm, hypertensive LMCA ≤4.13 mm, and hypertensive LMCA >4.13 mm).

RESULTS

The median value of the frontal planar QRS-T angle of all participants was 38°. Subjects with the widest frontal planar QRS-T angle were older (p = 0.027), were hypertensive (p = 0.001), and had higher corrected QT values (p = 0.001). Patients with the widest frontal planar QRS-T angle had larger LMCA and left anterior descending coronary artery diameters compared to subjects with a normal and borderline frontal QRS-T angle (p = 0.004 and p = 0.028, respectively). Corrected QT, HT, and LMCA diameter were found as independent predictors of the frontal planar QRS-T angle. Subjects with HT and a larger luminal caliber of LMCA had the widest frontal planar QRS-T angle.

CONCLUSION

Patients with a history of HT and a larger luminal caliber of LMCA had the widest frontal planar QRS-T angle. Since HT-induced electrophysiological changes are still not well established and we observed that changes in the luminal caliber of coronary arteries are associated with an abnormal frontal QRS-T angle, the frontal QRS-T angle could serve as a marker of ventricular repolarization heterogeneity in hypertensive patients in addition to keeping track of arrhythmic events, even before overt disease.

Effectiveness of Vitamin D Supplement Therapy in Chronic Stable Schizophrenic Male Patients: A Randomized Controlled Trial

In this study, the aim was to determine whether adding vitamin D to the standard therapeutic regimen of schizophrenic male patients with inadequate vitamin D status could improve some aspects of the symptom burden or not. This study was an open parallel label randomized clinical trial. Eighty patients with chronic stable schizophrenia with residual symptoms and Vitamin D deficiency were recruited randomly and then received either 600000 IU Vitamin D injection once along with their antipsychotic regimen or with their antipsychotic regimen only. Serum vitamin D was measured twice: first at the baseline and again on the fourth month. Positive and Negative Syndrome Scale (PANSS) was assessed at the baseline and on the fourth month. During the study, the vitamin D serum changes in vitamin group and control group were 22.1 ± 19.9(95%CI = 15.9-28.8) and 0.2 ± 1.7(95%CI = 0.2-0.8) (ng/mL) (p<0.001) respectively. The changes of PANSS positive subscale score (P) were -0.1±0.7 (95%CI =-0.3-0.1) and 0.00 ± 0.8 (95%CI = -0.2-0.2) in vitamin D and control group respectively (p=0.5). The changes of PANSS negative subscale score (N) were -0.1 ± 0.7 (95%CI = -0.3-0.05) and -0.1 ± 0.5 (95%CI = -0.2-0.04) in vitamin D and control group respectively (p = 0.7) and there was a negative but not significant correlation between serum vitamin D level changes and PANSS negative subscale score (r = -0.04, p = 0.7). We did not find a relationship between serum vitamin D level changes and the improvement of negative and positive symptoms in schizophrenic patients and more randomized clinical trials are required to confirm our findings.