re secondary HT, left ventricular ejection fraction,50, ischemic or dilated cardiomyopathy, atrial fibrillation, more than mild valvular disease, acute and chronic liver or renal diseases, immunological diseases, HIV, alcoholism and drug addiction and any other life-threatening disease. At least 2 months before study enrollment all patients were on stable medical therapy with angiotensin II receptor antagonist 50%, diuretics 45%, angiotensin-converting enzyme inhibitors 32%, b-blockers 21%, statins 26%, and calcium-channel blockers 19%. No statistically significant changes were observed in the different drugs administered during follow-up. None of the 220 patients finally studied presented cardiovascular events . Body mass index was calculated as the weight in kilograms divided by height in meters squared, and obesity was defined as body mass index.30 kg/m2. Glomerular filtration rate was calculated PubMed ID:http://www.ncbi.nlm.nih.gov/pubmed/22179956 using the modified diet in renal disease equation. All patients were followed up until the end of the study at month 24, with a threestage sample collection: basal, 12 months and 24 
months. All explorations were made in each stage. The procedure was approved by the appropriate institutional review boards or ethics review committees of each study center, and the study was conducted in accordance with the guidelines of good clinical practice and with ethical standards for human experimentation established by the Declaration of Helsinki. Every GLPG-0634 supplier patient signed a written informed consent for their inclusion in the study. NT-proBNP determination Samples were collected under standardized conditions to minimize sources of preanalytical variation. Venous blood was taken by venipuncture with the subjects in sitting position between 08:00 and 11:00 AM, centrifuged immediately, and frozen at 280uC. After thawing, serum NT-proBNP levels were determined in a single laboratory using the commercially available Elecsys proBNP sandwich, electrochemiluminescence immunoassay on an Elecsys 2010 Analyzer. The results are expressed as pg/ ml. The lower detection limit was 5 pg/ ml, and intra-assay variation was 2.6%. Methods Ethics statement All patients gave written informed consent to participate in the study. The project was approved by the local Ethics Committee and conducted in accordance with the guidelines of the Declaration of Helsinki. Patients The study was on 252 Caucasian asymptomatic hypertensive consecutive out-patients, from 11 participating hospitals. All patients underwent a routine physical examination, electrocardiogram, echo-Doppler study and laboratory analyses. Physicians using a standardized protocol measured systolic and diastolic blood pressure in the left arm of seated subjects between 08:00 and 11:00 AM, following the recommendations of The American Heart Association. Patients were included in the study between August 2007 and October 2007. Of the 252 subjects, 220 asymptomatic and stable patients were included in the study. Thirty-two were excluded during follow-up. We decided to analyze separately patients with and without LVH, because of the differences in cardiac structure and prognosis. Cytokine and cytokine receptor determination Venus blood was taken by venipuncture into pyrogen-free vacuum tubes containing EDTA, as anticoagulant, with the subjects in sitting position between 8:00 and 11:00 AM, centrifuged immediately, frozen at 280uC and only thawed once. Plasma concentrations of sTNF-R1 and IL-6 were determined at a central labor
