Luciana Neves Cosenso-Martin

Is there an association between vitamin D and hypertension

Vitamin D has an important role in bone mineralization and maintenance of calcium homeostasis. Thus, vitamin D deficiency is better characterized in the situations that involve the musculoskeletal system and bone metabolism. Recently, there is an interest in the association of vitamin D deficiency with the presence of metabolic syndrome, diabetes mellitus, cardiovascular disease and arterial hypertension. The mechanism underlying the inverse relationship between vitamin D levels and blood pressure is not completely understood, but it seems to involve several systems. Clinical and experimental studies suggest that vitamin D may influence blood pressure by regulating renin-angiotensin system, improving endothelial function, blunting cardiomyocyte hypertrophy, improving insulin sensitivity, reducing the concentrations of serum free fatty acids and regulating the expression of the natriuretic peptide receptor. In accordance with recent clinical studies and meta-analyses, the association between blood 25-hydroxyvitamin D concentrations and hypertension is controversy. There is no doubt about the role of vitamin D in skeletal health. However, the vitamin D supplementation to prevent or treat hypertension has been the subject of recent debate. Thus, the decision to use supplementation with vitamin D would be important in patients with vitamin D deficiency. This review article discusses the association between vitamin D and hypertension, vitamin D supplementation and some recent patents related to vitamin D and hypertension.

DPP-4 Inhibitor Reduces Central Blood Pressure in a Diabetic and Hypertensive Patient: A Case Report

AbstractHypertension and type 2 diabetes mellitus (DM) are among the main risk factors for the development of cardiovascular disease. Pharmacotherapy for DM should not only improve blood glucose control, but also provide beneficial glucose-independent cardiovascular effects. The central systolic blood pressure (SBP) has become more important than the brachial SBP in the assessment of cardiovascular risk.This case report describes the effect of vildagliptin, a dipeptidyl peptidase-4 (DPP-4) inhibitor, on the central SBP in a 54-year-old woman with hypertension and DM. She was submitted to applanation tonometry (AT) before and after vildagliptin association. AT of the radial artery is a non-invasive method that indirectly assesses arterial stiffness by calculating the central SBP and the augmentation index (AIx).After 3 months of follow-up using vildagliptin, central SBP and AIx were improved. Moreover, she presented better glycemic control.This case suggests an effect of DPP-4 inhibitor on arterial stiffness parameter (central SBP) in a hypertensive and diabetic patient, which shows a glucose-independent beneficial cardiovascular effect of this group of drugs.

Endothelial Changes in Individuals with Prehypertension

INTRODUCTION Prehypertension is considered a precursor of systemic arterial hypertension and a predictor of morbidity-mortality due to cardiovascular diseases, which are the main causes of death in Brazil and the world. Thus, early diagnosis and the adoption of therapeutic measures in cases of prehypertension can reduce cardiovascular risk. The aim of the present study was to perform a selective review of the literature to identify and discuss early endothelial changes in individuals with pre-hypertension. RESULTS AND DISCUSSION The findings indicate an increase in ET-1-mediated vasoconstrictor tone in prehypertension, with endothelial-dependent vasodilatation impairment. Moreover, significantly high levels of angiotensin, arginine and vasopressin were found in this group of patients. A reduction in endothelial fibrinolytic capacity was another important change found in patients with prehypertention and was associated with an increased risk for atherothrombotic events. CONCLUSION The present findings demonstrate endothelial changes in individuals with prehypertension that contribute to the development of arterial hypertension as well as a high risk for cardiovascular events, underscoring the importance of the early adoption of optimized therapeutic measures for this population.

Renin Angiotensin System Blockage Associates with Insertion/Deletion Polymorphism of Angiotensin-Converting Enzyme in Patients with Hypertensive Emergency

Hypertensive crisis (HC) stands out as a form of acute elevation of blood pressure (BP). It can manifest itself as hypertensive emergency (HE) or hypertensive urgency (HU), which is usually accompanied with levels of diastolic BP ≥120 mmHg. Angiotensin-converting enzyme (ACE) gene insertion/deletion (I/D) polymorphism may influence manifestations of HC. Thus, this study evaluated the influence of ACE I/D polymorphism in individuals with HC. A total of 187 patients admitted with HC (HU [n=69] and HE [n=118]) and 75 normotensive individuals were included in the study. Peripheral blood was drawn for a biochemical and genetic analysis of the ACE I/D polymorphism by Polymerase Chain Reaction. HC group showed higher systolic BP, body mass index (BMI), glycemia, creatinine, and lower high-density lipoprotein (HDL) cholesterol compared with normotensive individuals. The use of renin-angiotensin system (RAS) blockers was more frequent in the HU group than in the HE group (p=0.020). The II genotype was more predominant in normotensive and HU individuals than among HE individuals (18.7%, 11.6%, and 2.5%, respectively; p=0.004). Higher BMI and glycemia were associated with HC in the logistic regression model. ACE II genotype (odds ratio [OR] 0.14; 95% confidence interval [CI] 0.04-0.51) and HDL cholesterol were protective for the development of HE. ACE II genotype was present in the HU group, compared with the HE group (OR 0.18; 95% CI 0.04-0.88). This study shows an association between the low prevalence of ACE I/D polymorphism II genotype and a greater occurrence of HE in Brazilian individuals. The lower blockage of RAS, which was detected in the HE group, may interact with the low frequency of II genotype, conferring an increased risk for HE.

CIRCULATING LEVELS OF MATRIX METALLOPROTEINASE-9 ARE ELEVATED IN INDIVIDUALS WITH HYPERTENSIVE CRISIS

Objective: Matrix metalloproteinase-9 (MMP-9) participates in the degradation of components of the extracellular matrix and it is involved on vascular remodeling. The imbalance between their activation and inactivation mechanisms seems to be associated with vasomotor changes. The aim of this study was to investigate the plasma levels of MMP-9 in acute vascular alterations due to hypertensive crisis. Design and method: This cross-sectional study was performed in 40 normotensive (NT) and 58 controlled hypertensive subjects (CHyp) as well in 57 patients with hypertensive emergency (HypEmerg) and 43 in hypertensive urgency (HypUrg). Hypertensive crisis was divided in HypEmerg, which was characterized by elevated levels of systolic blood pressure (BP) higher or equal 180 mmHg and/or diastolic BP higher or equal 120 mmHg complicated with target-organ damage (TOD), and HypUrg, defined by BP elevation without TOD. The levels of MMP-9 were assessed using the Human Matrix metalloproteinase-9 Quantikine ELISA kit (R & D Systems, Inc., Minneapolis, MN, USA) with a calculation of medians being presented as nanograms per milliliter (ng/mL). Subsequently, MMP-9 values were transformed into logarithms to reflect normal distribution for statistical analysis. Results: The mean blood pressures were 116.5 ± 13.9/72.4 ± 10.6 mmHg for NT, 123.2 ± 12.6/79 ± 9.2 for CHyp, 194.1 ± 24.3/121.4 ± 17.3 for HypUrg and 191.6 ± 34.3/121.7 ± 18.8 mmHg for HypEmerg, respectively (p-value < 0.0001 between groups). MMP-9 levels were statistically different between the HypEmerg (log 2.31 ± 0.2) and HypUrg groups (log 2.17 ± 0.3) compared to the NT (log 1.94 ± 0.3) (p-value < 0.01 and p-value < 0.05, respectively) and CHyp groups (log 1.92 ± 0.2) (p-value < 0.01). There was no difference in the MMP-9 levels between the different clinical presentations of hypertensive crisis. Conclusions: Matrix metalloproteinase-9 concentrations are progressively higher in the order normotensive, controlled hypertensive, hypertensive urgency and emergency groups with significant differences between the hypertensive crisis groups (urgency and emergency) compared to the other groups. Therefore, MMP-9 may be a new biomarker in cases of acute elevations of blood pressure. Figure. No caption available.

INFLUENCE OF ANTIHYPERTENSIVE TREATMENT ON MMP-9 LEVELS IN CONTROLLED HYPERTENSIVE INDIVIDUALS

Objective: Ambulatory blood pressure monitoring (ABPM), in addition to peripheral blood pressure (BP) measurements, provides data on central hemodynamic, such as pulse wave velocity (PWV), augmentation index (AI 75%) and central pressure, which are associated with arterial stiffness. The development of arterial stiffness is related to an extracellular matrix enzyme called metalloproteinase-9 (MMP-9). The aim of the current study is to evaluate the correlation between the variables obtained by ABPM and levels of MMP-9 at different BP levels. Design and method: On-hundred and one individuals were enrolled: 21 normotensive (NT), 36 prehypertensive (PH), and 44 controlled hypertensive (CHT). Peripheral and central BP parameters were evaluated by ABPM using Mobil-O-Graph® 24-hour monitor and MMP-9 levels were determined in all participants. The levels of MMP-9 were assessed using the Human Matrix metalloproteinase-9 Quantikine ELISA kit (R & D Systems, Inc., Minneapolis, MN, USA) with a calculation of medians being presented as nanograms per milliliter (ng/mL). Subsequently, MMP-9 values were transformed into logarithms to reflect normal distribution for statistical analysis. Results: Age of the participants ranged from 30–71 years. MMP-9 concentration was significantly higher in the PH (log 4.74 ± 0.5) compared to CHT group (log 4.41 ± 0.5; p = 0.02). Mean PWV was greater in CHT than PH (8.1 ± 1.2 m/s vs. 6.9 ± 1 m/s; p-value = 0.0003, respectively), but no differences were found in AI 75% between CHT and PH groups. On the other hand, PH individuals had higher mean PWV than NT individuals (8.1 ± 1.2 m/s vs. 6.9 ± 1 m/s; p-value = 0.0003, respectively). MMP-9 levels correlated with cardiac output and peripheral vascular resistance in the three periods evaluated by ABPM (24 h, wakefulness and sleep). Conclusions: Prehypertensive individuals present greater arterial stiffness and MMP-9 levels than normotensive subjects, fact that demonstrate already structural alterations in this group. In its turn, higher levels of MMP-9 are observed in prehypertensive compared to controlled hypertensive subjects, suggesting that antihypertensive therapy may reduce MMP-9 plasma levels.