Teen-age boys have greater risk than girls of high blood pressure as adults

Study highlights:

• Teen-age boys are more likely than girls to develop high blood pressure in early adulthood.
• Even with normal blood pressure values, boys face three to four times higher risk than girls of developing hypertension.
• Body mass index at age 17 is associated with a future risk for hypertension in later life and should represent an alert for pediatricians to begin prevention as early as possible, researchers said.

DALLAS, June 14, 2010 — Teen-age boys with normal blood pressure are three to four times more likely than girls to develop high blood pressure early in adulthood, according to a large scale study published in Hypertension: Journal of the American Heart Association.

Researchers examined the natural history of the development of blood pressure from adolescence to young adulthood in 23,191 boys and 3,789 girls from average age 17 to 42 years, with regular and repeated readings of blood pressure and body mass index (BMI).

Participants were part of the Metabolic, Lifestyle, and Nutrition Assessment in Young Adults (MELANY) Study, conducted by the Israeli Defence Forces.

Previously, systolic blood pressures (the top number in a blood pressure reading) of 100, 105 and 110 were considered within the normal range for adolescents, researchers said. However, the study found that elevations in blood pressure within the normal range can be consistent with pre-hypertension and represent higher risk of developing hypertension in early adulthood (20s and 30s).

“Blood pressure values well below the hypertensive range already can serve as good predictors for future hypertension,” said Amir Tirosh, M.D., Ph.D., one of the study’s lead authors and a fellow in the Department of Medicine, Division of Endocrinology, Diabetes, and Hypertension at Brigham and Women’s Hospital in Boston, Mass. “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.”

During the follow-up period, 14 percent, or 3,810 people, developed hypertension.
Researchers examined the interaction between BMI and blood pressure, because of concerns about the current epidemic of overweight and obesity.

For boys, the risk of high blood pressure as young adults increases throughout the entire range of BMI, including what’s considered normal weight, a BMI of 18.5 to 25.

For girls, only the sub-group considered obese had substantially higher risk of high blood pressure. The sex hormone estrogen may protect against hypertension, explaining the sex differences researchers said.

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

For boys already in the upper range for normal weight, with systolic blood pressure 110 and above, the risk of hypertension increases at about 1 percent per year. So, already before the age of 30 years about 10 percent of that group will develop hypertension, Tirosh said.

“It is never too early to start lifestyle modification and intervene to prevent hypertension, heart disease and diabetes,” he said. “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 study findings apply to the United States and other industrialized nations, researchers said.

The Talpiot Medical Leadership Program, Chaim Sheba Medical Center, Tel-Hashomer, Israel and the Israeli Defence Forces Medical Corps funded the study.

Co-authors are: Arnon Afek, M.D., M.H.A.; Assaf Rudich, M.D., Ph.D.; Ruth Percik, M.D.; Barak Gordon, M.D.; Nir Ayalon, M.D.; Estela Derazme, M.P.H.; Dora Tzur, M.P.H.; Daphna Gershnabel, M.D.; Ehud Grossman, M.D.; Avraham Karasik, M.D.; Ari Shamiss, M.D., M.P.A. and Iris Shai, R.D., Ph.D. Author disclosures are on the manuscript.

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Statements and conclusions of study authors published in American Heart Association scientific journals are solely those of the study authors and do not necessarily reflect the association’s policy or position. The association makes no representation or guarantee as to their accuracy or reliability. The association receives funding primarily from individuals; foundations and corporations (including pharmaceutical, device manufacturers and other companies) also make donations and fund specific association programs and events. The association has strict policies to prevent these relationships from influencing the science content. Revenues from pharmaceutical and device corporations are available at www.americanheart.org/corporatefunding.  

NR10 – 1090 (Hypertension/Tirosh)

Editor’s Note: The American Heart Association’s Start! initiative encourages all Americans to participate in regular physical activity. Start! includes personalized walking plans for people at any fitness level. Visit startwalkingnow.org to download the plans and locate Start! Walking Paths near you.

More resources:
• High Blood Pressure
• Healthier Kids
• AHA Diet and Lifestyle Recommendations
• The American Heart Association has downloadable stock footage at
www.americanheart.mediaroom.com then click on “Multimedia.”