The number of children seen as inpatients in US hospitals nearly doubled in the ten years leading up to 2006, according to a new study published online in the journal Hypertension this week that also drew attention to the associated dramatic increase in healthcare cost.

The lead author of the national study, the first to examine high blood pressure hospitalizations in American children, was Dr Cheryl Tran, pediatric nephrology fellow in the Department of Pediatric Nephrology at the University of Michigan in Ann Arbor.

She told the media that while you might expect there to be a rise in costs as a result of a rise in the numbers, “the economic burden created by inpatient childhood high blood pressure was surprising”.

For the study, Tran and colleagues analyzed records for the years 1997, 2000, 2003 and 2006 from the Healthcare Cost and Utilization Project (HCUP) Kids’ Inpatient Database and found that the number of children in the US treated in hospital for hypertension as inpatients nearly doubled from 12,661 in 1997 to 24,602 in 2006.

The children most likely to be treated in hospital for high blood pressure were African-American boys, aged 10 and over. They were also more likely to be treated in a teaching hospital.

The researchers said children treated for high blood pressure tended to stay in hospital for an average of 8 days compared to the average of 4 days for other illnesses.

They also calculated that the charges for inpatient care for children with high blood pressure went up by 50% over the decade, reaching an estimated $3.1 billion.

Outpatient charges would increase this figure even further, but the researchers could not say by how much because those costs are unknown at a national level.

The biggest increases were for children with high blood pressure and end stage kidney disease:

“The coexisting condition of end-stage renal disease resulted in a significant increase in healthcare charges,” write the authors.

Speculating on the reason behind these increases, Tran and colleagues suggested the biggest factor is likely to be the rise in childhood obesity.

When they examined the reasons why children were admitted to hospital, and where high blood pressure fitted in, they found:

  • The most common diagnoses were pneumonia, acute appendicitis and asthma.

  • When high blood pressure was the primary diagnosis, then the secondary diagnoses were for convulsive disorder, headache, obesity and systemic lupus erythematosus.

  • When high blood pressure was in any diagnoses, the most common primary diagnoses were lupus, complications of kidney transplant, pneumonia and acute proliferative glomerulonephritis.

Acute proliferative glomerulonephritis is a condition that causes kidney inflammation that can in turn lead to high blood pressure.

Tran said these findings suggest doctors and health professionals should be encouraging healthy lifestyle habits when they see children during well visits to reduce high blood pressure.

The American Heart Association (AHA) estimates that 1 to 3% of American children have high blood pressure, with 32% of under-20s being overweight and 17% being obese.

High blood pressure increases a child’s risk of having it as an adult, which in turn increases the risk of heart problems and stroke later in life, says the AHA.

Written by Catharine Paddock PhD