Abstract 17413: Influence of Endothelial Function and Rho-Associated Kinase Activity in Patients With Primary Aldosteronism

Abstract

Background: Primary aldosteronism (PA) is a most common cause of secondary hypertension and patients are divided into two subtypes in clinically, aldosterone producing adenoma (APA) and idiopathic hyperaldosteronism (IHA). Hypertension is associated with endothelial dysfunction. It is well known that endothelial dysfunction is an independent predictor of cardiovascular events. Rho-associated kinases (ROCKs), one of the first downstream targets of the small GTP-binding protein Rho A, mediate various cellular physiologic functions. It has been reported that an increase in ROCK activity is associated with cardiovascular diseases, including hypertension. However, there is little information on the relationship between subtype of PA and the grade of atherosclerosis. The purpose of this study was to evaluate the vascular function and ROCK activity in patients with PA. Methods: Vascular function, including peripheral arterial tonometry (PAT) and ROCK activity in peripheral leukocytes were evaluated in 18 patients with APA group (49.5±15.5 years, 7 males), 14 patients with IHA group (56.1±11.0 years, 8 males), and 23 age-, gender-, and blood pressure-matched EH group (55.6 ± 9.9 years, 13 males). Results: PAT ratio was significantly lower in the APA and IHA groups than in the EH group (0.62±0.23 vs. 0.62±0.24 and 0.79±0.28, P<0.05, respectively), whereas there was no significant difference in PAT ratio between the APA group and IHA group. ROCK activity was significantly higher in the APA group than in the IHA group and EH group (1.36±0.58 vs. 0.95±0.51 and 0.80±0.39, P<0.05 and P<0.001, respectively), whereas there was no significant difference in ROCK activity between the IHA group and EH group. PAT ratio correlated with plasma aldosterone concentration (PAC) (r=-0.36, P<0.01) and plasma renin activity ratio (ARR) (r=-0.26, P=0.05). ROCK activity correlated with serum potassium (r=-0.27, P=0.05), PAC (r=0.39, P<0.01) and ARR (r=0.49, P<0.01). Conclusions: APA and IHA were associated with endothelial dysfunction and APA increased ROCK activity compared with those in IHA and EH. These findings suggest that APA may have a higher risk of future cardiovascular events.