Search

Background: Overactivation of renin-aldosterone-angiotensin system (RAS) is part of the pathogenesis of obesity-associated hypertension. Evidences have shown that weight loss can result in reduction in blood pressure and RAS. This study was aim to investigate changes of plasma aldosterone concentration (PAC) after bariatric surgery. Methods: A prospective study was done in 14 morbidly obese patients undergoing bariatric surgery. Patients who were taking medications that can interfere with PAC and renin levels were excluded. Collection of blood samples were done at baseline and at 3 and 6-month post-bariatric surgery. Results: Four out of 14 patients had hypertension at baseline. Mean body mass index (BMI) was 56.7 ± 13.5 kg/m2. PAC were significantly decreased at 3-and 6-month post-bariatric surgery from 14.3 ± 8.0 to 7.5 ± 5.5 [reduction of 36% from baseline (P < 0.01)] and 8.0 ± 6.6 ng/dl [reduction of 32% from baseline (P < 0.05)] respectively. The reduction of PAC at 3-month post-surgery was correlated with the reduction of body weight (r = 0.46, P < 0.05), waist circumference (r = 0.73, P < 0.05) and percent of body fat (r = 0.58, P < 0.05). Conclusions: Maximal reduction of PAC in obese patients underwent bariatric surgery occurred during the first 3 months after bariatric surgery. The reduction of PAC was associated with the reduction of body weight, waist circumference and percent of body fat suggesting the link between RAS and obesity-mediated hypertension. [ABSTRACT FROM AUTHOR]

Abstract: The first oral direct renin inhibitor, aliskiren, recently received approval for the treatment of hypertension. This article addresses the premise, promise, and potential limitations of this new class of renin-angiotensin system inhibitor. Although aliskiren adds to a list of more than 100 drugs approved for the treatment of hypertension, its introduction into clinical medicine is of particular interest because of the novel mechanism of action: inhibition of renin’s catalytic activity, the most proximal and rate-limiting step in renin-angiotensin system activation. By producing more complete renin-angiotensin system inhibition than with existing agents, direct renin inhibitors may afford greater protection from hypertensive complications. Other potential advantages include additional blood pressure reduction when used in combination therapy, a placebo-like side-effect profile, avid renal concentration, and long duration of action. Potential limitations include modest levels of blood pressure reduction that are equivalent to but not greater than angiotensin receptor blockers, reduced gastrointestinal absorption with a high-fat meal, and large reactive increases in renin secretion—the functional importance of which is under intense investigation. The results of outcomes trials are eagerly awaited. [Copyright &y& Elsevier]