Secular trends of blood pressure and body size in a multi-ethnic adolescent population: 1986 to 1996.

Objectives: To determine the levels and time trends of blood pressure and body size in a healthy population of youth.

Study Design: Minneapolis, Minnesota, fifth through eighth grade public school children (aged 10 to 14 years) were surveyed in 1986 and 1996. Blood pressure, height, and weight were measured by technicians trained to the same rigorous protocol at each time period, and comparisons were made between the 2 groups (1986 and 1996).

Results: In 1986 and 1996, 8222 and 10,241 children, respectively, were measured with participation rates of over 93%. African American, Hispanic, Native American, Asian, and non-Hispanic white groups were all represented. Systolic blood pressure was significantly higher and diastolic blood pressure lower in 1996 than in 1986 in all ethnic and gender groups. Weight and body mass index (wt/ht2) were significantly higher in all groups in 1996. Adjustment for body size largely eliminated the systolic blood pressure differences but had no effect on measured diastolic blood pressure.

Conclusions: Body size and systolic blood pressure are rising among school children. Weight and body mass index show substantial increases over 10 years (1986-1996). Diastolic blood pressure fell for unclear reasons. These changes may have future health implications for cardiovascular disease, as these youth move into adulthood.