Children with high blood pressure tend to become adults with high blood pressure - highlighting the need to take steps early to counter the condition, researchers reported Monday.

In a review of 50 studies conducted since the 1970s, researchers at Johns Hopkins University, Baltimore, found that childhood blood pressure tended to “track” into adulthood. Children whose blood pressure was high for their age, sex and height - particularly in adolescence - were at greater risk of having elevated numbers as adults.

The findings are published in the American Heart Association’s journal Circulation.

“Early detection and intervention is important to overcoming high blood pressure,” Dr. Youfa Wang, the senior researcher on the study, said in a statement.

Lifestyle measures, like regular exercise and a diet rich in fruits, vegetables, whole grains and low-fat dairy, are preferred over medication for controlling children’s blood pressure, Wang noted.

Wang and colleague Dr. Xiaoli Chen also pointed out that a healthy lifestyle has numerous other benefits, including weight control. Past research has suggested that overweight children are at greater risk of developing high blood pressure.

In adults, high blood pressure is defined as a blood pressure of 140 millimeters of mercury (mm Hg) or higher when the heart beats (the systolic pressure), or a pressure of 90 mm Hg or higher between beats (the diastolic pressure). The two readings are expressed as 140 over 90, or 140/90.

There are no such specific thresholds for children, however. Children’s blood pressure naturally rises as they get older, and it varies according to their sex and height. So their blood pressure is compared with that of other children their age, sex and height, and reported as a percentile.

The American Heart Association recommends that all children ages 3 and older have their blood pressure checked yearly.

SOURCE: Circulation, June 24, 2008.