Search

Summary: A link between serum uric acid and the development of hypertension was first hypothesized in the 1870s. Although numerous epidemiologic studies in the 1980s and 1990s suggested an association, relatively little attention was paid to it until recently. Animal models have suggested a two-step pathogenesis by which uric acid initially activates the renin angiotensin system and suppresses nitric oxide, leading to uric acid–dependent increase in systemic vascular resistance, followed by a uric acid–mediated vasculopathy, involving renal afferent arterioles, resulting in a late sodium-sensitive hypertension. Initial clinical trials in young patients have supported these mechanisms in young patients but do not yet support pharmacologic reduction of serum uric acid as first-line therapy for hypertension. [Copyright &y& Elsevier]

Abstract: Background: The purpose of this study was to analyze the effects of changes in the diagnosis and treatment of pheochromocytoma in a pediatric population. Methods: We reviewed the medical records of all children who had resection of pheochromocytoma or paraganglioma at a major children’s hospital since 1968. Results: Fifteen children underwent surgery at 11.9 ± 4.2 years of age. Presenting symptoms included headache, hypertension, and sweating. Three children had a mutation of the succinate dehydrogenase enzyme, and 1 child had nonsyndromic, familial pheochromocytoma. The most sensitive diagnostic modalities included 24-hour urinary and plasma norepinephrine and 24-hour urinary total metanephrines, magnetic resonance imaging, and 123I–meta-iodobenzylguanidine scintigraphy. Laparoscopic cortical-sparing adrenalectomy was performed in 3 patients with von Hippel-Lindau disease. Compared with those with open procedures (n = 7), patients who had laparoscopic resection (n = 5) had a statistically shorter hospital length of stay, and time to eating ambulation. Conclusions: The addition of 123I–meta-iodobenzylguanidine scanning, genetic testing, and laparoscopic surgery has changed the diagnosis and treatment of pheochromocytoma in children. Laparoscopic cortical-sparing adrenalectomy can be accomplished safely and is the preferred treatment for children at risk for multifocal disease. [Copyright &y& Elsevier]

Hypertension is the most common form of cardiovascular disease. Although it is less common in adolescents than in adults, hypertension and the associated organ damage can and often does begin early in life. Consequently, for many with high blood pressure (BP), measures directed at the long-term prevention of cardiovascular morbidity may need to be started in adolescence to achieve maximal effectiveness. This article discusses some of the problems unique to hypertension in the young, as well as recent discoveries regarding the likely role played by increases in serum uric acid level in the development of adolescent-onset essential hypertension. [ABSTRACT FROM AUTHOR]

Hypothesis: Uric acid, nephron number, and the pathogenesis of essential hypertension. Background. Essential hypertension affects more than 25% of the world's population. Genetic, physiologic, and epidemiologic studies provide clues to its origins, but a clear understanding has been elusive. Recent experimental and clinical studies have implicated uric acid in the onset of essential hypertension. Methods. In a retrospective chart review, we identified 95 children with confirmed, new onset hypertension, and evaluated the cause of hypertension and parental history of hypertension, birth weight, and serum uric acid. In an open-label, cross-over trial we treated 5 children with confirmed essential hypertension with allopurinol as single treatment agent, and screened for change in blood pressure by casual and ambulatory methods. In tissue culture experiments, we evaluated the effect of uric acid on glomerular endothelial cell function. Results. Elevation of serum uric acid is related to the onset of essential hypertension in children, reduced birth weight, and endothelial dysfunction. Normalization of uric acid appears to ameliorate new onset essential hypertension. Conclusion. These findings, combined with animal model data, support the hypothesis that uric acid has a key role in the pathogenesis of early onset essential hypertension, and may unify some of the disparate theories of the origins of essential hypertension. [ABSTRACT FROM AUTHOR]

Background 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). Purpose To describe the background and design of the Serum Urate Reduction to Prevent Hypertension (SURPHER) study. Methods SURPHER is a single center, double-blinded, crossover trial in which participants are randomly assigned to allopurinol (300 mg) or placebo. Enrollment focused on adults 18–40 years old with baseline systolic blood pressure ≥ 120 and < 160 mm Hg or diastolic blood pressure ≥ 80 and < 100 mm Hg, and serum urate ≥ 5.0 mg/dL or ≥ 4.0 mg/dL for men or women, respectively. SURPHER recruitment targets participants without chronic kidney disease (estimated glomerular filtration rate > 60 mL/min/1.73 m2), 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 24 hour 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. Results Since June 16, 2014 until present, SURPHER is recruiting participants in the city of Birmingham, Alabama. Limitations 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. [ABSTRACT FROM AUTHOR]