These results demonstrate that uric acid stimulates proliferation, angiotensin II production, and oxidative stress in VSMC through tissue RAS. This suggests that uric acid causes cardiovascular disorders by stimulating the vascular RAS, and this stimulation may be mediated by the MAP kinase pathway.

Abstract-It has been reported that hypertension and obesity often coexist with hyperuricemia. To clarify the relations between serum uric acid, plasma norepinephrine, and insulin or leptin levels in subjects with weight gain-induced blood pressure elevation, we conducted the present longitudinal study. In 433 young, nonobese, normotensive men, body mass index, blood pressure, and levels of serum uric acid, fasting plasma norepinephrine, insulin, and leptin were measured every year for 5 years. Subjects were stratified by significant weight gain and/or blood pressure elevation (Ͼ10% in body mass index or mean blood pressure) for 5 years. At entry, blood pressure, uric acid, and norepinephrine values in subjects with blood pressure elevation were greater than in those without it, although body mass index, insulin, and leptin were similar. At entry, body mass index, blood pressure, uric acid, and norepinephrine in subjects with weight gain were greater than in those without weight gain. The increases in body mass index, mean blood pressure, uric acid, norepinephrine, insulin, and leptin for 5 years were greater in subjects with blood pressure elevation and/or weight gain than in subjects without, and those increases were greatest in subjects with weight gain whose blood pressure was elevated. By multiple regression analysis, basal mean blood pressure, norepinephrine, and uric acid were significant determinant factors of changes in mean blood pressure over 5 years, and basal body mass index, norepinephrine, and uric acid were significant determinant factors of changes in body mass index. These results demonstrate that serum uric acid and plasma norepinephrine concentrations predict subsequent weight gain and blood pressure elevation. Key Words: uric acid Ⅲ sympathetic nervous system Ⅲ obesity Ⅲ hypertension, obesity E levated serum uric acid (UA) is associated with increased rates of cardiovascular events, 1-3 and hyperuricemia is frequently observed in obese subjects and hypertensive patients. 4 -8 Several lines of evidence, both epidemiologic and clinical, point to a close interrelation between hyperuricemia, hypertension, and obesity. 2-8 Also, it is known that both hypertension and obesity are related to sympathetic overactivity, 9 -17 hyperinsulinemia, and insulin resistance. 18,19 However, the relation of insulin resistance and sympathetic nervous overactivity to hypertension and obesity is still controversial. 11,15,20 These and other investigations have documented the coexistence of elevated UA level, sympathetic overactivity, and hyperinsulinemia in hypertension and obesity, but the precise relation has not been clarified.The goal of the present longitudinal study was to clarify the interrelation of serum UA level, sympathetic activity, insulin, and leptin levels in subjects with weight gain-induced blood pressure (BP) elevation. We sequentially studied the accompaniments of spontaneous weight gain-induced BP elevation for 5 years, especially focusing on serum UA, sympathetic activity, and plasma levels of ...

We investigated the relation between changes in the renin-aldosterone axis and reduction in blood pressure in 25 obese patients placed on a 12-week reducing diet; sodium intake was either medium (120 mmol) or low (40 mmol). Plasma renin activity (PRA) declined with weight loss, so that by 12 weeks there was a significant decrease in PRA (P less than 0.01) as well as plasma aldosterone (P less than 0.05), regardless of sodium intake. Weight loss with low sodium intake was equal to that with medium intake. The reduction in PRA but not in aldosterone correlated with weight loss in both sodium-intake groups (r = 0.58). Mean arterial pressure fell significantly and equally in both groups, correlating with weight loss throughout the study (r = 0.56) and with PRA from the fourth through 12th weeks (r = 0.48) These results demonstrate that weight loss is accompanied by reductions in PRA and aldosterone; PRA reductions, irrespective of sodium intake, may contribute to the decline in blood pressure.