The researchers reviewed hospital discharge data for the study. They included all children aged 2 to 18 who were treated for hypertension during hospitalizations, regardless of their primary diagnosis or the main reason why they were hospitalized.
Those most likely to have high blood pressure were older than 9, male and African-American, according to the study. Some had end-stage renal (kidney) disease.
The study found children with hypertension had an average length of stay of eight days- double that of non-hypertensive kids.
Childhood obesity may play a role in the sharp increase in hospitalizations.
American Heart Association spokesman Dr. Ernesto Schiffrin from the Department of Medicine at McGill University, Montreal, Quebec said obesity seems to be an even stronger risk factor for high blood pressure in children than it is in adults.
"Increasingly, these are children with essential hypertension- this is consequence of the epidemic of obesity and diabetes that is found increasingly in teenagers and younger children," he said.
"If we are going to prevent adult hypertension, we have to start at this early age by avoiding obesity, cutting back on salt and exercising- otherwise this will increase further the prevalence of adult hypertension and the huge costs that will occur accordingly."
Image: Child getting blood pressure taken, via Shutterstock.