title: The effects of urate lowering therapy on inflammation, endothelial function, and blood pressure (SURPHER) study design and rationale.
abstract: The association between hyperuricemia and hypertension is controversial. Animal models, epidemiological data, and small clinical trials have favored a causative role for hyperuricemia in hypertension but more studies are necessary to elucidate putative mechanisms, population susceptibility, and potential for urate-lowering therapies (ULT) to decrease blood pressure (BP).
  
  
  
  To describe the background and design of the Serum Urate Reduction to Prevent Hypertension (SURPHER) study.
  
  
  
  SURPHER is a single center, double-blinded, crossover trial in which participants are randomly assigned to allopurinol (300mg) or placebo. Enrollment focused on adults 18-40years old with baseline systolic blood pressure≥120 and <160mmHg or diastolic blood pressure≥80 and <100mmHg, and serum urate ≥5.0mg/dL or ≥4.0mg/dL for men or women, respectively. SURPHER recruitment targets participants without chronic kidney disease (estimated glomerular filtration rate>60mL/min/1.73m2), and without prior diagnosis of gout or use of ULT to treat gout. The primary outcome is change from baseline in blood pressure assessed by 24hour ambulatory blood pressure monitoring and mechanistic outcomes include changes in endothelial function as measured by flow-mediated dilation, as well as C-reactive protein levels.
  
  
  
  Since June 16, 2014 until present, SURPHER is recruiting participants in the city of Birmingham, Alabama.
  
  
  
  The study aims to enroll otherwise healthy young adults for a pharmacological intervention study with multiple study-related procedures. Challenges related to recruitment are anticipated and multiple strategies for increasing recruitment and retention are planned if necessary.
authors: Department of Medicine, Division of Clinical Immunology and Rheumatology, University of Alabama at Birmingham, AL 35294, USA.
authors: Michael B
authors: MB
authors: Saddekni
authors: Department of Medicine, Division of Clinical Immunology and Rheumatology, University of Alabama at Birmingham, AL 35294, USA.
authors: Kenneth G
authors: KG
authors: Saag
authors: Department of Medicine, Division of Cardiovascular Disease, University of Alabama at Birmingham, AL, 35294, USA.
authors: Tanja
authors: T
authors: Dudenbostel
authors: Department of Medicine, Division of Cardiovascular Disease, University of Alabama at Birmingham, AL, 35294, USA.
authors: Suzanne
authors: S
authors: Oparil
authors: Department of Medicine, Division of Cardiovascular Disease, University of Alabama at Birmingham, AL, 35294, USA.
authors: David A
authors: DA
authors: Calhoun
authors: Department of Medicine, University of Alabama at Birmingham, AL 35294, USA.
authors: Sebastian E
authors: SE
authors: Sattui
authors: Department of Pediatrics, Division of Nephrology, University of Alabama at Birmingham, AL 35294, USA.
authors: Daniel I
authors: DI
authors: Feig
authors: Department of Epidemiology, University of Alabama at Birmingham, AL 35294, USA.
authors: Paul
authors: P
authors: Muntner
authors: Department of Biostatistics, University of Alabama at Birmingham, AL 35294, USA.
authors: David T
authors: DT
authors: Redden
authors: Department of Medicine, Division of Clinical Immunology and Rheumatology, University of Alabama at Birmingham, AL 35294, USA.
authors: Phillip J
authors: PJ
authors: Foster
authors: Department of Medicine, Division of Clinical Immunology and Rheumatology, University of Alabama at Birmingham, AL 35294, USA.
authors: Elizabeth J
authors: EJ
authors: Rahn
authors: Department of Medicine, Division of Clinical Immunology and Rheumatology, University of Alabama at Birmingham, AL 35294, USA.
authors: Stephanie R
authors: SR
authors: Biggers
authors: Department of Biostatistics, University of Alabama at Birmingham, AL 35294, USA.
authors: Peng
authors: P
authors: Li
authors: Department of Medicine, Division of Clinical Immunology and Rheumatology, University of Alabama at Birmingham, AL 35294, USA. Electronic address: agaffo@uabmc.edu.
authors: Angelo L
authors: AL
authors: Gaffo
mesh_terms: D000293:Adolescent; D000328:Adult; D001741:Black or African American; D000493:Allopurinol / Q000627:therapeutic use*; D001794:Blood Pressure / Q000187:drug effects*; D018592:Cross-Over Studies; D004311:Double-Blind Method; D004730:Endothelium, Vascular / Q000187:drug effects*; D005260:Female; D006074:Gout Suppressants / Q000627:therapeutic use*; D006801:Humans; D033461:Hyperuricemia / Q000188:drug therapy* / Q000208:ethnology; D018836:Inflammation Mediators / Q000378:metabolism*; D008297:Male; D012107:Research Design; D012737:Sex Factors; D014527:Uric Acid / Q000097:blood; D055815:Young Adult
chemical_list: D006074:Gout Suppressants; D018836:Inflammation Mediators; D014527:Uric Acid; D000493:Allopurinol
keywords: Allopurinol; Blood pressure; Endothelial function; Hypertension; Hyperuricemia; Prehypertension; Serum urate; Urate lowering therapy (ULT); Uric acid