06/18/2012 06:50 pm ET

High Blood Pressure Hospitalizations For Kids Double

Hospitalizations for children with high blood pressure have nearly doubled in recent years, according to new data.

Researchers said the substantial increase may stem, in part, from childhood obesity, which now affects about 17 percent of children and teens in the U.S.

"Oftentimes we think that [hypertension] is a disease of adults," said Dr. Debbie Gipson, an associate professor of pediatrics and communicable diseases at the University of Michigan Health System and an author on the study. "This reminds us that our children have hypertension, and they have it enough that they end up in the hospital."

Pediatric hospitalizations in the U.S. increased from about 12,000 in 1997 to 24,000 in 2006, according to the data, published in the journal Hypertension, Tuesday.

Estimates suggest that between 1 and 3 percent of children in the U.S. have hypertension. According to the American Heart Association,a "normal" blood pressure level is relative among children, and doctors must make a calculation based on gender, height and age.

Heart and kidney disease can lead to blood pressure issues in children. The authors of the new study found that many children with hypertension in their discharge records were first diagnosed with something else, such as kidney conditions, lupus or pneumonia.

They also found that overall, the average hospital stay for children with high blood pressure doubled compared with those of other ill children. "Here we see that in children with other health conditions, high blood pressure is complicating things," said Gipson.

High blood pressure was listed as a primary reason for hospitalization for some children, which may indicate that their health issues are going unchecked.

"Children with primary hypertension are usually only hospitalized if they have difficult-to-control hypertension, or if we suspect there is something else that may be a factor," said Dr. Elaine Urbina, director of preventive cardiology at the Cincinnati Children's Hospital, who was not involved with the new study. "Sometimes, it's a non-compliance with medication, others we've gone on to check for renal [problems]."

Urbina agreed with the study's hypothesis that obesity is playing a significant role in the increase in high blood pressure hospitalizations, although she cautioned that the database used did not have information on body mass index. Only 9 percent of the claims that included a diagnosis for high blood pressure indicated the child was overweight, although the authors said obesity is not often included in discharge papers because it isn't typically reimbursible.)

However, past research suggests that children who are obese have three times the risk of developing hypertension. The connection between high blood pressure and weight is very well established, but less clear is the long-term health effects.

"When there's high blood pressure occurring in children, what's the impact when they're adults?" she asked. "That's one of the issues that continues to be before us."