Doctors fail to diagnose high blood pressure in more than three-quarters of children with the problem, putting them at risk for heart disease and other organ damage later in life, a new study suggests.
Calculating elevated blood pressure in children is more complicated than in adults, and many doctors might not bother evaluating kids' pressure because they assume hypertension is an adult problem, the study found.
"Hypertension is a disease that doesn't cause symptoms, particularly in children," said Dr. Richard Lange, chief of clinical cardiology at the Johns Hopkins University School of Medicine, who did not participate in the study. "But it starts to affect the blood vessels to the heart, kidney and brain, and many of the effects could be irreversible."
The condition, which is largely treatable, affects as many as 5 percent of children and is becoming more prevalent as obesity increases, researchers said in a paper published yesterday in The Journal of the American Medical Association.
They examined the medical records of 14,187 children between the ages of 3 and 18 who had at least three routine checkups in which their blood pressure was taken. The checkups occurred between June 1999 and September 2006.
The review determined that 507 children, or 3.6 percent, had high blood pressure, also known as hypertension. Of those cases, 376, or 74 percent, weren't diagnosed.
Also, 485 children, or 3.4 percent, had prehypertension, a term for blood pressure on the high end of the normal range. Of those cases, only 55, or 11 percent, were properly diagnosed.
Dr. David C. Kaelber, the lead researcher and a fellow at Harvard Medical School, told the Associated Press that untreated high blood pressure in children can eventually damage the heart, kidneys, eyes and brain. It also puts children at a higher risk for stroke, heart attack, kidney failure and hardening of the arteries.
Children who were taller, older and obese were more likely to be diagnosed with high blood pressure. Also those whose pressure readings stood out to doctors because of how abnormal they were, were more likely to be diagnosed with the condition, Kaelber said.
Kaelber, who practices at Children's Hospital in Boston, urged parents to talk to their children's doctors. "Just as now most parents, when they go to their pediatrician, they ask: 'How is my child growing? How is my child's weight?'" he said, "I would just encourage parents to add a third question: 'How is my child's blood pressure?'"
Dr. Richard Ringel, a pediatric cardiologist at Hopkins, said there are many possible explanations for doctors' failure to diagnose hypertension in their young patients.
"Many of the kids that we see come into the office so anxious, so nervous, that ... you take the first blood pressure, and by the time you take it again at the end of the visit, you very often have a 10- to 20-point drop," he said. So doctors may dismiss a high reading as anxiety, not an underlying pathology.
Hopkins' Lange said screening children in school might catch hypertension in pre-teens and teens who visit doctors less often than younger children.
He argued that the root cause of most childhood hypertension - the obesity epidemic - also needs attention. "It stems from our lifestyle - inactivity and obesity," he said.
But Dr. Robert Blake, a pediatrician at the St. Joseph Medical Center in Towson, noted that the problem doesn't always stem from lifestyle. Problems regulating blood pressure are more common among African-American children than others, Blake said. In some cases, he said, the problem is best treated with medication.
He agreed, however, that most childhood hypertension is preventable. "It boils down to maintaining proper body weight for body height, looking at your diet including sodium intake and the amount of exercise you're doing," he said.
Dr. Susan R. Mendley, director of pediatric nephrology at the University of Maryland Medical Center, said it might be difficult for pediatricians to deliver the news to parents. "Physicians are reluctant to make a bad diagnosis if they can't be confident," she said. "It's a tough thing to explain that the child might have a problem, but we won't know for decades."
Today's pediatricians, she said, must see themselves in a new light. "We've always been preventers of childhood illnesses," she said. "But we really have to see children as soon-to-be young adults and make sure we do all we can to protect them from the diseases of adulthood."
Sun wire services contributed to this article.
Childhood high blood pressure
About 2 million American children are thought to have high blood pressure, but many cases go undiagnosed.
Children who are taller, older and obese are more likely to have high blood pressure than shorter, younger and slimmer children.
High blood pressure can lead to problems with heart, liver, kidneys and other organs later in life.
Difficulty regulating blood pressure is more common in African-American children.
All children should have their blood pressure checked at least once a year. Doctors should compare the reading to charts showing normal pressure for the child's age, height and weight.
[ Sources: Published medical papers, interviews with doctors and the American Heart Association]