Epidemiology of primary hypertension in the young.

This presentation is to provide a broad epidemiologic perspective on the problem of blood pressure in childhood and adolescence and a background for the presentations which follow, addressing the aspects of tracking, risk factors, and electrolytes. Two fundamental issues are addressed here: first, the different patterns of blood pressure by age, as observed in population surveys in the USA, Japan, and elsewhere around the world; and second, the relation of blood pressure to indices of growth and development at different ages during childhood and adolescence. The pattern of blood pressure by age in the young is often more complex than the simple linear pattern ascribed to adult populations. The relations of blood pressure to body measurements are strong but vary importantly with age. The implications of these observations for the design of future epidemiologic studies are discussed.