Vitamin D receptor gene polymorphisms and plasma renin activity in essential hypertensive individuals.

Several studies analyzed 25-hydroxyvitamin D (25[OH]D) and blood pressure (BP) relationship with mixed results. Moreover, a relationship between the risk of hypertension and vitamin D receptor (VDR) gene polymorphisms, FokI and BsmI, was reported. This study was aimed to analyze these relationships in essential hypertensive (EH) patients. Seventy-one EH patients, 18-75 years old, were enrolled. Patients underwent clinical BP, 24-h ambulatory BP monitoring, 25[OH]D and plasma renin activity (PRA) evaluations. FokI and BsmI VDR polymorphisms were analyzed and compared with those of 72 healthy controls. In EH patients, the median 25[OH]D levels were lower than 30 ng ml(-1). We found a significant negative correlation between 25[OH]D and 24-h systolic BP (r = -0.277, P = 0.043). This correlation persisted in backward stepwise multivariate analyses (ß = -0.337; P = 0.022), after adjustment for age, gender, body mass index, glomerular filtration rate, and PRA. We did not observe statistically significant correlation between 25[OH]D and PRA. We compared the allelic frequencies and genotype distribution between patients and controls, and FokI and BsmI VDR polymorphisms were not associated either with hypertensive status or with PRA. Further wide studies are needed to clarify this relationship.

Correlation between low folate levels and hyperhomocysteinemia, but not with vitamin B12 in hypertensive patients.

INTRODUCTION: Hypertension is considered to be among the most important risk factors for cardiovascular and cerebrovascular diseases. In recent years, several investigators have reported that high plasma levels of total homocysteine (t-hcy) has a key role in the development of hypertension, and the deficiency of B complex vitamins could increase the risk of hypertension. The purpose of this study was to investigate the relationship between plasma homocysteine, folate and vitamin B12 in hypertensive patients. MATERIALS AND METHODS: In 116 patients with hypertension and 81 healthy subjects, total plasma homocysteine, vitamin B12 and folate levels were measured. RESULTS AND DISCUSSION: Homocysteine was significantly higher in patients than in control subjects (22.9±3.5 versus 9.0±2.3 µmol/L respectively, p<0.001); the folate plasma concentrations in hypertensive patients were significantly lower than in control subjects (6.7±5.0 ng/ml and 9.0±4.4 ng/ml respectively, p<0.05). Moreover, no differences in vitamin B12 plasma levels were observed when comparing the levels of hypertensive patients and those of the controls (440±223 pg/ml vs 491±185 pg/ml respectively, p>0.05). Our results confirmed that, as previously observed, elevated t-hcy levels and low folate levels, but not vitamin B12 levels, are significantly associated with hypertension.

Clinical correlates of renal dysfunction in hypertensive patients without cardiovascular complications: the REDHY study.

Our study was aimed to assess the clinical correlates of different degrees of renal dysfunction in a wide group of non-diabetic hypertensive patients, free from cardiovascular (CV) complications and known renal diseases, participating to the REDHY (REnal Dysfunction in HYpertension) study. A total of 1856 hypertensive subjects (mean age: 47+/-14 years), attending our hypertension centre, were evaluated. The glomerular filtration rate (GFR) was estimated by the simplified Modification of Diet in Renal Disease Study prediction equation. A 24-h urine sample was collected to determine albumin excretion rate (AER). Albuminuria was defined as an AER greater than 20 microg min(-1). We used the classification proposed by the US National Kidney Foundation's guidelines for chronic kidney disease (CKD) to define the stages of renal function impairment. In multiple logistic regression analysis, the probability of having stage 1 and stage 2 CKD was significantly higher in subjects with greater values of systolic blood pressure (SBP) and with larger waist circumference. SBP was also positively related to stage 3 CKD. Stage 3 and stages 4-5 CKD were inversely associated with waist circumference and directly associated with serum uric acid. Age was inversely related to stage 1 CKD and directly related to stage 3 CKD. The factors associated with milder forms of kidney dysfunction are, in part, different from those associated with more advanced stages of renal function impairment.

Association between biomarkers of inflammation and left ventricular hypertrophy in moderate chronic kidney disease.

AIMS: Left ventricular hypertrophy (LVH) is a predictor for cardiovascular mortality, and it is considered to be a surrogate marker of preclinical cardiovascular disease. This study aimed at evaluating whether fetuin-A plasma levels are decreased in patients with moderate chronic kidney disease (CKD) and their linkage to plasma concentrations of hs-C-reactive protein (CRP), cardiotrophyn-1 (CT-1), tumor necrosis factor-ac (TNF-alpha), propeptide of collagen Type I (PIP) and to LVH. MATERIAL AND METHODS: We enrolled 64 moderate CKD and 55 essential hypertensives (EH) with normal renal function as controls. All the patients underwent an echocardiographic examination; plasma samples were obtained to measure routine clinical parameters and the molecules listed above (measured by ELISA). RESULTS: Among CKD there were 30/64 patients with LVH, and in EH group 14/55 subjects had LVH. Fetuin A was reduced in CKD when compared with EH (p < 0.0001). The comparison between CKD having LVH with those without LVH showed significant differences in plasma levels of fetuin-A (p < 0.002), TNF-alpha (p < 0.01) and hs-CRP (p < 0.001), CT-1 and PIP (p < 0.002). CKD with LVH had lower values of fetuin-A (p < 0.001), and higher values of hs-CRP (p < 0.001) TNF-alpha (p < 0.001), CT-1 (p < 0.001) and PIP (p < 0.001) than EH with LVH. The multivariate analysis of correlation demonstrated that in CKD patients hs-CRP (beta 0.42, p < 0.00006), and systolic blood pressure (beta 0.29, p < 0.02) were independent predictors of LV mass index. The relationship between LV mass index and fetuin-A did not reach statistical significance. CONCLUSIONS: For the first time in moderate CKD patients, we demonstrate that fetuin-A is decreased and relates to LVH depending on C-reactive protein.

Microalbuminuria and early endothelial activation in essential hypertension.

We hypothesized that in essential hypertensive patients (EHs), plasma levels of pro-atherogenic adhesion molecules would be increased and related with urine albumin excretion (UAE). Thus, this study was aimed at evaluating biochemical markers of endothelial activation and their relationship with UAE in a group of patients with uncomplicated EH. In basal condition soluble forms of adhesion molecules intercellular adhesion molecule (ICAM)-1 and vascular cell adhesion molecule (VCAM)-1, as well as 24-h UAE were assayed. One hundred patients with essential hypertension and no diabetes or ultrasonographic evidence of atherosclerosis were included in the study. Seventy normotensive healthy subjects served as controls. EHs were first studied overall, than were divided into two subgroups: those with UAE > or =20 mcg/min MAUs and those with UAE <20 mcg/min (non-MAUs). ICAM-1 (P<0.001) and VCAM-1 (P<0.0001) plasma concentrations were higher in EHs than in controls. Microalbuminuric EHs had greater levels of adhesion molecules than non-MAUs (ICAM-1 P=0.04; VCAM-1 P=0.02, respectively). In EHs UAE was correlated with ICAM-1 (r=0.29, P=0.003), and VCAM-1 (r=0.30, P=0.002). These associations were confirmed in multiple regression models (P=0.02 for both ICAM-1 and VCAM-1) including, along with adhesion molecules, age, body mass index and blood pressures. Our findings show that in essential hypertension there is a very early activation of endothelial adhesion molecules favouring atherosclerosis.