Blood-pressure levels are rising among young Americans, according to a study published Tuesday which raises concern over potential health problems when the children grow up.
The study also suggested that what children eat and how much they exercise may be important factors -- in addition to previously recognized weight problems -- contributing to the increase.
“These results suggest that in another 10 to 20 years we will be facing much higher rates of hypertension, heart disease and stroke as these children become adults,” said Paul Muntner of Tulane University in New Orleans, chief author of the report.
His study, published in this week’s Journal of the American Medical Association, compared readings from two samples of children, each aged 8 to 17, taken from 1988 to 1994 and again in 1999 and 2000. In all more than 5,500 children were involved.
It found that systolic levels -- the higher of the two numbers in a blood-pressure reading -- increased an average of 1.4 millimeters of mercury over the period of the study. The diastolic level, the lower number, rose by 3.3. The average blood pressure reading rose to 106/61 from 104/58.
Blood pressure is normally lower in children than adults, and normal ranges in children vary by age and sex. In adults a range of from 120/80 to 139/89 is considered elevated ”prehypertension” by the American Heart Association.
Increases found across most racial, ethnic groups
Increases occurred in both readings among black, Mexican-American and white boys and girls of all ages, the report said. Mexican-American and black children recorded average levels about two to three points higher compared with whites, it said.
Blacks in general are known to run a higher risk of blood pressure problems, for genetic and other reasons. A separate study Monday, published in the Archives of Pediatrics & Adolescent Medicine, suggested caffeinated soft drinks and other beverages may play a role in pushing up blood-pressure levels among black youths.
For Mexican-Americans studied in the Tulane report, the higher readings were due largely to a sharper increase in the number who were overweight, the authors said.
The report cited an earlier study which recently found that 15.5 percent of adolescent U.S. boys and girls are now overweight, up from 11.3 percent of boys and 9.7 percent of girls 15 years ago.
Poor diet, lack of exercise to blame?
However, researchers said less than 30 percent of the overall blood-pressure increase noted in the study can be attributed to weight gain.
Diet and exercise may also be a major factor, Muntner said. ”We assume a lot of the increase in blood pressure levels is related to changes in the way children are eating and exercising,” he said.
For example, sodium, often found in processed foods, is a known risk factor for increasing blood pressure.
The study recommended fighting high blood pressure among children and adolescents with programs that include weight control, increased physical activity, and changes in diet.
“Such interventions could have a profoundly positive impact on the prevalence of high blood pressure in the United States,” the report said.