Francesca Tornese

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 (β=−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.

FLOW MEDIATED DILATION, ENDOTHELIAL AND INFLAMMATORY BIOMARKERS IN HYPERTENSIVES WITH CHRONICH KIDNEY DISEASE: PP.6.227

Objectives: Hypertension is characterized by a synergy between oxidative stress, inflammation and endothelial dysfunction. Endothelial dysfunction plays an important role in the patho-physiology of high blood pressure, of atherosclerosis and cardiovascular diseases. In the last decade, a technique for non-invasive assessment of flow mediated vasodilation (FMD) of the brachial artery, an endothelium dependent function, which assesses endothelial function in vivo was developed. The purpose of our study was to analyze the relationship between endothelial dysfunction, assessed by FMD, and biomarkers of endothelial dysfunction (ET-1, ICAM-1, VCAM-1), and inflammation (TNF-α) in patients with hypertension having chronic renal failure (CRF). Methods: Have been enrolled 50 subjects with hypertension (HT), with various degrees of kidney function (CRF II-IV), and 50 healthy control subjects. In all subjects plasma concentrations of ET-1, ICAM-1, VCAM-1, E-SEL and TNF-á were determined. In hypertensive subjects the analysis of endothelial function was carried out by FMD. Results: Overall, the results showed in HT plasma levels of ET-1, ICAM-1, VCAM-1, E-SEL and TNF-α significantly higher (p < 0.001) than in control subjects. The average value of FMD% as assessed in the group of hypertensive subjects was of 4.57 ± 1.08. The linear correlation analysis showed in hypertensive subjects, negative correlations and statistically significant of FMD% with ET-1, ICAM-1, VCAM-1, E-SEL, and TNF-α (p < 0.05 respectively). The analysis of correlation between FMD% and glomerular filtrate rate, as estimated by the MDRD study equation at 4 variables, was not statistically significant. Conclusions: Our study confirms, in hypertensive patients with different degrees of renal function, the presence of endothelial activation characterized by increased serum concentrations of adhesion molecules and markers of inflammation. These results are associated with reduced endothelium-dependent vasodilatation, regardless of the degree of renal function.

The Relationship between an Oxidative Stress Biomarker and Plasma Haemoglobin in Patients with Chronic Kidney Disease

AbstractIntroduction: Evidence suggests that decreased haemoglobin plasma concentration may be a predictor of adverse cardiovascular events in patients with chronic kidney disease (CKD). We hypothesized that in CKD patients, oxidative stress could influence the development of cardiovascular damage via a relationship with haemoglobin levels. Methods: We assayed plasma levels of the biomarker of oxidative stress 8-ISO-prostaglandin F2α (8-ISO-PGF2α) and of haemoglobin in 193 stage 2–5 CKD patients, investigating their relationship. Eighty healthy subjects and 80 patients with primary hypertension having normal renal function were enrolled as controls. Results: The CKD group was divided according to 8-ISO-PGF2α quartiles, and decreasing levels of both haemoglobin and estimated glomerular filtration rate (eGFR) along with increasing quartiles were observed. In the 193 CKD patients, the linear analysis of correlation showed inverse correlations of 8-ISO-PGF2α with both haemoglobin and eGFR (r = −0.47; r = −0.81; p < 0.00001, respectively). In the control groups, no correlation between haemoglobin and 8-ISO-PGF2α was found. The multiple regression analysis carried out in CKD patients, by a model with 8-ISO-PGF2α as the dependent variable, and including haemoglobin and all confounding factors, confirmed the inverse relationship between haemoglobin and 8-ISO-PGF2α (β = −0.50; p < 0.00001). In this model, only when eGFR was added did the relationship between haemoglobin and 8-ISO-PGF2α lose statistical significance. In this final multivariate model, 8-ISO-PGF2α correlated independently with eGFR (β = −0.82; p < 0.0001). Conclusions: In CKD, haemoglobin plasma level is inversely related to oxidative stress, depending on GFR. It remains to be elucidated whether or not the biochemistry of nitric oxide and haemoglobin interaction has a role in causing this relationship.