Association of cardiovascular risk factors and endothelial dysfunction in Japanese hypertensive patients: Implications for early atherosclerosis

Although hypertension, hyperlipidemia, diabetes and smoking are known risk factors of atherosclerosis in Caucasians, their relative contributions to early atherosclerosis among Japanese are unknown. Decrease in flow-mediated dilation (FMD) of the brachial artery is a useful marker of endothelial dysfunction and early atherosclerosis. To evaluate the relative contribution of hypertension to early atherogenesis, we determined FMD, as well as plasma levels of tissue-type plasminogen activator (t-PA; a sensitive index of endothelial damage) and tumor necrosis factor (TNF)-alpha and interleukin (IL)-6 (established markers of inflammation) in normotensive and hypertensive patients under treatment. FMD was significantly reduced as the number of risk factors increased, suggesting that accumulations of risk factors were related to endothelial dysfunction. FMD was reduced in hypertensives (9.9+/-5.8 (SD) %) compared to normotensives (14.6+/-7.6, p<0.01) despite good blood pressure control (139+/-20/80+/-14 mmHg in hypertensives). Nitroglycerine-induced endothelium-independent vasodilation was not altered in hypertensives (16.0+/-6.3%) as compared to normotensives (16.7+/-5.8). Plasma t-PA, TNF-alpha, and IL-6 levels were increased in hypertensives despite good blood pressure control. Thus, hypertension alone is a high risk for early atherosclerosis. Persistent endothelial damage and moderate inflammation may increase the risk of early atherosclerosis synergistically under the presence of hypertension in Japanese.