Adolescent BP Predicts Progression to Hypertension in Young Adulthood

From Medscape Medical News

Laurie Barclay, MD

June 18, 2010 — Adolescent blood pressure (BP) predicts progression to hypertension in young adulthood, with teen-age boys with normal BP 3 to 4 times more likely than girls to have high BP early in adulthood, according to the results of a study reported online June 14 in Hypertension.

"Although prehypertension at adolescence is accepted to indicate increased future risk of hypertension, large-scale/long follow-up studies are required to better understand how adolescent ...BP tracks into young adulthood," write Amir Tirosh, MD, PhD, from Brigham and Women's Hospital in Boston, Massachusetts, and colleagues.

The study cohort consisted of 23,191 male and 3789 female adolescents enrolled in the Metabolic Lifestyle and Nutrition Assessment in Young Adults study. At baseline, mean age was 17.4 years, and BP was less than 140/90 mm Hg or categorized according to current criteria for pediatric BP and body mass index (BMI) values. Incidence of hypertension was determined retrospectively between the ages of 17 and 25 years and prospectively with repeated BP measurements between the ages of 25 and 42 years.

Between the ages of 17 and 42 years, 3810 new cases of hypertension were detected, with a cumulative risk for hypertension 3 to 4 times higher in men vs women, based on survival analyses. Cox regression models adjusted for age and BMI and stratified by baseline BP showed that the hazard ratio (HR) of hypertension increased gradually across BP groups within the normotensive range at age 17 years. There was no apparent threshold effect. In the group with BP 130 to 139/85 to 89 mm Hg, the HR was 2.50 (95% confidence interval [CI], 1.75 - 3.57) for boys and 2.31 (95% CI, 0.71 - 7.60) for girls.

"Blood pressure values well below the hypertensive range already can serve as good predictors for future hypertension," Dr. Tirosh said in a news release. "The rate of progression to hypertension is higher in teen-agers whose systolic blood pressure is 110 versus those whose blood pressure is 100 and is different between boys and girls."

Even after adjustment for BP at age 17 years, BMI at that age was strongly associated with a future risk for hypertension, especially in boys. However, BMI at age 30 years attenuated this association, especially in girls.

"BMI is considered an independent risk factor that interacts with blood pressure to predict future risk of hypertension," Dr. Tirosh said. "Together, these factors provide a simple and useful tool that can serve as a red flag to detect subgroups of teens at high risk of hypertension as adults while in their teens."

Limitations of this study include single-visit measurement of BP at age 17 years in a fairly stressful setting, higher-stress military environment in the study cohort, and database of age 17 years limited to rather basic information.

"It is never too early to start lifestyle modification and intervene to prevent hypertension, heart disease and diabetes," Dr. Tirosh concluded. "Hypertension, heart disease and their prevention have been perceived as more relevant to an older population, but now we know that slight changes in blood pressure and weight should represent an alert for pediatricians to begin prevention as early as possible. It is better to prevent a disease than treat it."

The Talpiot Medical Leadership Program, Chaim Sheba Medical Center, Tel-Hashomer, Israel, and the Israeli Defense Forces Medical Corps funded this study. The study authors have disclosed no relevant financial relationships.

Hypertension. Published online June 14, 2010.