Adolescent Blood Pressure and Early Age Stroke.

Background: Underdiagnosis of relevant risk factors has contributed to the increasing stroke incidence in young adults. Blood pressure cut-off values for adolescents are neither sex specific nor based on cardiovascular outcomes.

Methods: This nationwide, population-based, retrospective cohort study included all Israeli adolescents 16-19 years of age who were medically evaluated before compulsory military service from 1985 to 2013, including routine blood pressure measurements. The primary outcome was the first occurrence of a stroke (ischemic or hemorrhagic) at a young age (≤52 years), as documented in the Israeli National Stroke Registry. Cox proportional hazard models were stratified by sex and adjusted for birth year, sociodemographic variables, and adolescent body mass index.

Results: The cohort comprised 1,897,048 adolescents (42.4% women). During 11,355,476 person-years of follow-up, there were 1470 first stroke events at a young age. In men, an adolescent diastolic blood pressure value of ≥80 mmHg, compared with the reference group (diastolic blood pressure value of <70 mmHg), was associated with an increased risk of stroke (adjusted hazard ratio 1.28; 95% confidence interval [CI], 1.04 to 1.58), while a diastolic blood pressure value of 70-79 mmHg was not associated with an increased risk of stroke (adjusted hazard ratio 1.11; 95% CI 0.90 to 1.34). Among women, an adolescent diastolic blood pressure value of ≥80 mmHg, compared with the reference group (diastolic blood pressure value of <70 mmHg) was associated with an increased risk of stroke at a young age (adjusted hazard ratio 1.38; 95% CI 1.03 to 1.88), as was a diastolic blood pressure value of 70-79 mmHg (adjusted hazard ratio 1.41; 95% CI 1.09 to 1.81). Elevated adolescent systolic blood pressure values (≥120 mmHg) were not associated with an increased risk of stroke.

Conclusions: Diastolic blood pressure values of ≥80 mmHg in adolescence were associated with an increased risk of stroke at a young age in both men and women. No similar association was observed for elevated systolic blood pressure.