BACKGROUND:

Hypertension has been clearly identified as a major risk factor for coronary heart disease and stroke. Hypertension screening and intervention programs for children are based on the concept that high normal blood pressure may be the childhood antecedent of adult hypertension or that blood pressure 'tracks' through childhood, adolescence, and adulthood. Blood pressure tracking has been well established for adults and young adults but results from various studies in children are controversial. At a Symposium on High Blood Pressure in the Young in 1979, it was concluded that there was insufficient information to recommend specific interventions for prepubertal children with blood pressure levels in the upper percentiles of the blood pressure distribution. Studies of longer duration with large population sizes and repeated blood pressure measurements over time were required to determine if blood pressure levels at these young ages were predictive of adult hypertension.

DESIGN NARRATIVE:

In the Spring of 1978 a total of 10,423 children, ages 6-8 were screened. A subsample was invited to join the study of blood pressure measurement. The sample was selected as follows: all children in the top five percent of the initial systolic blood pressure distribution; all children in the bottom five percent of the initial systolic blood pressure distribution; a random sample of one in two of the remaining Black children; a random sample of one in nine of the remaining white children; and all the remaining children of other races. Included were families of about 200 Native American children. Of 2,641 selected children, 878 refused leaving a sample of 1,753. Baseline data on age, race, sex, triceps skinfold thickness, dietary history, urinary sodium and potassium excretion, physiological measures, life event changes, medical history, demographic data and body size measurements of children and their parents were collected at the first home interview conducted between 1978 and 1979. The children were followed twice per year in 1978 to 1980 and 1982 to 1985 for blood pressure and body size. Annual measurements were made of blood pressure, height, weight, skinfold thickness, and body girths. Screenings continued through early 1991 when the cohort was 19-21 years of age.

Several substudies were conducted including the relationship of red blood cell cation transport to essential hypertension, Type A behavior assessments, and familial aggregation of coronary-prone behavior.