The distribution and associations of blood pressure in an adolescent population.

In this report we describe the distributions of blood pressure and its associations in adolescence. Six hundred and twenty-five subjects aged 13 to 18 were drawn from three general practices in different urban and rural settings. Systolic pressures were higher and rose with age in boys (mean = 119 mm Hg) compared with girls (mean = 114 mm Hg), who showed no age association. Diastolic pressures (phase 5) were higher in girls (mean = 64 mm Hg) than in boys (mean = 60 mm Hg) and showed no association with age in either sex. Initial blood pressures were generally higher than those recorded after a further five minutes' rest in the sitting position, although diastolic pressures rose on the second reading in the older subjects. Systolic pressures of subjects from the suburban practice and in the late autumn were relatively low; diastolic pressures tended to be lower in the spring and in subjects from the rural practice. Systolic pressures were lower in the morning and this was found to be primarily related to fasting status. Individuals with a positive family history of hypertension had significantly higher blood pressures than those with a negative history. Boys who frequently played sports had lower diastolic pressures, largely accounting for the above sex difference. We conclude that although blood pressure measurement in adolescence is a difficult screening procedure it should be offered to selected groups such as those with a family history of hypertension.