Blood pressure levels in urban school-age population in Chile.

Two blood pressure (BP) measurements separated by 3 months were performed according to international guidelines on 2976 students (11 to 19 years) of different economic levels. Obesity was defined based upon height and weight. With the first measurements, 59th and 95th percentile value distribution curves were defined. Systolic hypertension (SH) was found in 9.5%; 10.2% were males and 8.9% females. The sample showed that 8.1% were obese (240 cases); among them the incidence of SH increased to 28.8% (69 cases) (p less than 0.01). In the entire sample, diastolic hypertension (DH) was 4.3%; males, 2.7%, and females, 5.5% (p less than 0.01). Among obese students, DH increased to 8.3% (20 cases) (p less than 0.01), and showed prevalence figures of 5.8% for obese males and 10.3% (14 cases) for obese females. After a second measurement, DH for the sample decreased to 1.8%. Salt intake and familial antecedents of high BP showed differences between hypertensive and normal populations.