[Risk factors for cerebrovascular diseases]

Cardiovascular diseases have been increasing in association with life style changes and increasing trends of hyperlipidemia and diabetes in Japan. On the other hand, cerebrovascular diseases, which largely comprise of small-vessel diseases such as hypertensive brain hemorrhage and lacunar brain infarction, have been considered to be dependent on aging and hypertension. Recently, however, atherothrombotic brain infarction (ATBI) has been rapidly increasing in Japan, and this increase occurs precedently in urban area such as Kanto and Kansai Districts. The present paper, therefore, summarizes the classification of diverse subtypes of cerebrovascular diseases and their underlying vascular lesions. Furthermore, it also focuses the risk factors for cerebrovascular diseases and the vascular lesions, and aims to clarify the factors and background which may have contributed to the increase of ATBI in Japan. Arteriosclerotic changes of small arteries in the brain parenchyma are considered to play an important role in development of cerebral white matter lesions (leucoaraiosis) and lacunar infarction. Oxidative stresses such as smoking, lipid peroxidation, and others are suggested to give impacts on the lesion formation through the effects on various functions of arterial trees and nitric oxide (NO) production from the arterial endothelial cells. Therefore, This paper presents the data indicating the significant correlation of these oxidative stress markers and polymorphism of endothelial NO synthase gene which may be relating to the pathogenesis of cerebral white matter lesions, and discusses about the usefulness of these new risk factors for cerebrovascular diseases.