New Focus on Hypertension in Children
The patient, a 12-year-old girl, had been suffering from periodic bouts of sweating, headaches and stomachaches. Over the past two or three months, the child had lost 20 pounds, and she complained about not being able to see well. At one time her blood pressure measured normal, but now it was 220/160, dangerously high. Puzzled by the girl’s symptoms, her doctor, a local pediatrician, called Dr. Ellin Lieberman, chief of the nephrology division at Childrens Hospital of Los Angeles.
Even as she listened over the telephone, Lieberman suspected the cause of the problem. When the child was brought into Childrens Hospital for tests, the doctor’s hunch was confirmed: The girl was suffering from a very rare, benign tumor that secretes adrenal hormones called a pheochromocytoma. She was given drugs to bring her blood pressure under control and, when her symptoms had subsided, surgery was performed to remove the tumor. She gained back 30 pounds in six weeks, and today, three years later, is doing fine.
On another occasion, a hospital outside of Los Angeles sent a 9-year-old boy to Lieberman for evaluation. The boy was suffering from crippling stomach pains so severe they made him double over. Nothing else seemed to be wrong with him, but his blood pressure was 230/160. When doctors at Childrens performed an arteriogram--a procedure which uses X-rays to trace the course of arteries in the body--they found that the boy had a narrowing of his aorta and of the arteries going to his kidneys. Over the next several years, a surgeon performed a number of operations to bypass the affected arteries. Today, the 9-year-old is a man of 18 years, has no symptoms and his blood pressure is normal.
Although these two patients suffered from very different conditions, what they had in common provided the most important clue to their diagnoses: high blood pressure. Yet only recently has the medical profession come to understand that high blood pressure can be a problem in children as well as adults. Until about 10 years ago, pediatricians seldom took regular blood-pressure readings from their patients.
“It used to be, why bother taking a child’s blood pressure?” said Lieberman, one of a handful of national experts on hypertension in children. “And now, the type of dialogue that occurs is, ‘I’ve taken the blood pressure, the results are as follows, what does it mean?’ ”
Children, like adults, can develop both primary and secondary hypertension. Primary hypertension (which used to be called essential hypertension) has no known cause, but it is often associated with obesity and a high-salt diet. The children of adults with primary hypertension are at a higher risk for the disease, which can lead to heart attacks and strokes if blood pressures are not kept under control.
Secondary hypertension is a byproduct of another underlying condition. In children, the main causes are kidney disease, narrowing of the arteries or hormone imbalances. Once the underlying cause is cured, the blood pressure usually returns to normal.
‘Very High Numbers’
Although hypertension does not occur at a high rate in the young--about 1% of children under 12 have high blood pressure--Lieberman said that “one out of 100 children is very high to a pediatrician.” Moreover, the prevalence of hypertension increases as children get older, up to 6% in adolescents. “Again,” said Lieberman, “we are talking very high numbers for a pediatric population.”
Lieberman, 54, was born Ellin Louria in Brooklyn, N.Y. Her father was a distinguished surgeon, and her brother later also became a doctor. Her husband, Harry M. Lieberman, also a pediatrician, works for the Kaiser Permanente group in Los Angeles.
Lieberman attended Radcliffe College and the Boston University School of Medicine. While an intern at Boston University’s teaching hospital, she worked with Dr. Robert Wilkins, a pioneer in the treatment of hypertension. In 1959, she came to Childrens Hospital as a fellow in what was then called the metabolics and renal division. In 1967, the unit became the division of nephrology and Lieberman became its head, a position she has held ever since. Lieberman is also a professor of pediatrics at USC Medical School.
Couldn’t Find Answers
She first encountered the problem of child hypertension in 1970, when she was trying to treat a 1-year-old child with kidney disease and high blood pressure. “When I went to the scientific literature, I could not find any answers to my set of questions,” she recalled. “In contrast to the literature that was available in 1970 concerning adults, there was nothing about that type of case. The mechanisms of hypertension, the prevalence of hypertension, and the management of hypertension in pediatrics was not covered. So you had to go from the ground up, as they say, ‘OJT,’ on-the-job-training.”
At about the same time, several pediatricians around the country had begun to study high blood pressure in children, which marked the first time the medical profession had really looked at the problem. “We didn’t even have (studies to show) normal blood pressures,” said Lieberman. “We didn’t know what the blood pressure distribution was.”
As a result, doctors could not be sure if a particular reading was too high or too low, and had to rely primarily on their personal experience to make these judgments. The problem was compounded because different physicians used different techniques to measure blood pressure in children, especially in infants.
The situation improved greatly when a series of studies, sponsored by the National Heart, Lung and Blood Institute, provided figures upon which pediatricians could base decisions about what a child’s blood pressure should be. Another breakthrough occurred in 1977, when the journal Pediatrics published the first guidelines for the detection and treatment of hypertension in children. But, Lieberman said, doctors are still “having trouble with the gray zone. We know what is absolutely normal, we know what is absolutely abnormal. And in between, we have a few problems.”
Hard to Design Regimen
One ongoing problem for pediatricians who have patients with primary hypertension is designing a drug regimen that will get blood pressures down to safe levels. “Because of the hazards of prescribing drugs for young children, and because the pharmaceutical industry can only devote so many dollars to so many studies, they tend not to study hypertensive agents in young children,” Lieberman said.
“Therefore we have to piece together a therapeutic regimen. It’s not quite by trial and error, but it’s by extrapolation and application, and a lot of analysis and a lot of discussion (with the children’s) families.” Lieberman added that while she can “understand the drug industry’s point of view, nevertheless, we still have to treat them, or we have to cope with the knowledge that these children are candidates for stroke, heart attacks or renal (kidney) failure.”
Even when a suitable drug therapy can be devised, its effectiveness depends a great deal on the child’s willingness to stay on it. Moreover, a patient in need of ongoing care can often fall between the cracks of the medical system as he or she gets older. “As they get into late adolescence, they need to create a relationship with a physician or a health system so they don’t get lost,” said Lieberman. “We are concerned that they leave medical coverage when they are age 18, and the medical system doesn’t catch up with them until they get sick, say, in their mid-20s. The individuals themselves need to understand the need for regular health care, without feeling like invalids.”
Hypertensive children need to be counseled about avoiding habits which can raise their blood pressure to dangerous levels, such as gaining too much weight or eating too much salt. They also must avoid a number of common drugs, ranging from certain common decongestants and other cold remedies to cortisone, certain oral contraceptives, and street drugs such as amphetamines and PCP. Lieberman said that chronic abusers of street drugs can suffer permanent kidney damage and highly elevated blood pressures.
Sports Recommended
Although isometric exercises such as weightlifting raise blood pressure and are not recommended, competitive sports which provide an aerobic workout are good for keeping blood pressure down, even if a child is on drug therapy, she said. Yet many school athletic programs require weightlifting, creating a dilemma for an adolescent who wants to compete. “We need to get the coaches involved with physicians who are knowledgeable about sports medicine,” said Lieberman. “There needs to be a dialogue, and at the present time that forum has not developed.”
While Lieberman and a number of other specialists around the country are working to develop better treatment regimens for their hypertensive patients, the growing recognition of the problem is leading to more research into the causes of high blood pressure in both children and adults.
According to Dr. Ronald Lauer, a professor of pediatrics at the University of Iowa and a national leader in this area, much of the research is focusing on the relationship between the development of hypertension in children and its appearance later in adulthood. Because doctors have only recently begun to take regular blood pressure readings in their young patients, there is little way to know whether adults who now suffer from hypertension also had the problem when they were children.
“There’s been an interest in finding where high blood pressure comes from,” said Lauer. “Does it start in childhood? There is still a little uncertainty about what high blood pressure means in children.” Although it is already known that the children of adults with hypertension are to some degree genetically predisposed to develop the disease themselves when they grow up, Lauer said that some current research is focusing on environmental factors, such as a family’s salt intake and overall nutrition. To the extent that the environment plays a role, it may be possible to forestall the development of hypertension by changing these habits at an early age.
Parents’ Key Role
In the meantime, Lieberman said, parents can play an important role in detecting and preventing hypertension in their children. “The most important thing I think the public should learn in this area,” she explained, “is that if they have a history themselves of high blood pressure, particularly if it’s not secondary to kidney problems or something they know about, their children should be checked.”
Lieberman said parents should also try to prevent their children from becoming overweight, and should limit their salt intake. And they should know about some of the symptoms of high blood pressure. Although victims of primary hypertension usually have no overt signs, if a child complains of frequent headaches, especially if the pain is throbbing and is located in the forehead rather than in the temples, the child should be taken to the doctor.
Finally, Lieberman said that although most pediatricians now routinely take blood pressure readings, parents should not be shy to request one if it is overlooked. “Blood pressure measurement is an integral part of the physical exam,” she said. “There is no reason it shouldn’t be taken.”
