Prevalence of persistent prehypertension in adolescents.

Objective: To measure the prevalence of persistent prehypertension in adolescents.

Study Design: We collected demographic and anthropometric data and 4 oscillometric blood pressure (BP) measurements on 1020 students. The mean of the second, third, and fourth BP measurements determined each student's BP status per visit, with up to 3 total visits. Final BP status was classified as normal (BP <90th percentile and 120/80 mm Hg at the first visit), variable (BP ≥ 90th percentile or 120/80 mm Hg at the first visit and subsequently normal), abnormal (BP ≥ 90th percentile or 120/80 mm Hg at 3 visits but not hypertensive), or hypertensive (BP ≥ 95th percentile at 3 visits). The abnormal group included those with persistent prehypertension (BP ≥ 90th percentile or 120/80 mm Hg and <95th percentile on 3 visits). Statistical analysis allowed for comparison of groups and identification of characteristics associated with final BP classification.

Results: Of 1010 students analyzed, 71.1% were classified as normal, 15.0% as variable, 11.5% as abnormal, and 2.5% as hypertensive. The prevalence of persistent prehypertension was 4.0%. Obesity similarly affected the odds for variable BP (OR, 3.9; 95% CI, 2.5-6.0) and abnormal BP (OR, 3.4; 95% CI, 2.0-5.9), and dramatically increased the odds for hypertension (OR, 38.4; 95% CI, 9.4-156.6).

Conclusion: Almost 30% of the students had at least one elevated BP measurement significantly influenced by obesity. Treating obesity may be essential to preventing prehypertension and/or hypertension.