From Medscape Pediatrics
New European Society of Hypertension Guidelines for Management of High Blood Pressure in Children: An Expert Interview With Empar Lurbe, MD, PhD
Hypertension in the pediatric population is an ongoing concern; in response, the European Society of Hypertension recently released new guidelines. Lead author Empar Lurbe, MD, PhD, spoke to Medscape about the guidelines, and why hypertension needs to be addressed in this young population. Dr. Lurbe is from the Department of Pediatrics at Consorcio Hospital General, the University of Valencia, Spain. She was the lead author of the new guidelines, "Management of High Blood Pressure in Children and Adolescents: Recommendations of the European Society of Hypertension" published in the Journal of Hypertension. She spoke to Medscape's Pippa Wysong.
Medscape: Guidelines addressing hypertension in children and adolescents were published in the United States in 2004. Why are new guidelines needed now?
Dr. Lurbe: The necessity for guidelines has become increasingly clear to physicians in light of growing evidence that cases of mild hypertension in children and adolescents are much more common than previously thought. In addition, progress made in pathophysiologic and clinical research has made clear links between pediatric hypertension and cardiovascular disease later in life, highlighting the need for improved cardiovascular prevention strategies for pre-adult individuals.
The Task Force set up by the European Society of Hypertension has combined considerable amounts of scientific data with clinical experience to represent a consensus among specialists involved in the detection and control of high blood pressure (BP) in children and adolescents. It is hoped that the publication of these guidelines will call attention to the huge burden of hypertension in this young population, and encourage public policymakers to develop a global effort to improve identification and treatment of high BP among young people. Primarily, however, these guidelines provide practical strategies for diagnosing and treating hypertension in children and adolescents.
Medscape: What adverse health effects are caused by uncontrolled hypertension in children? Are they different than those in adults?
Dr. Lurbe: There has been a lot of work on the pathophysiology and epidemiology of high blood pressure in children over the past couple of decades. Hypertension can cause organ damage in the heart, blood vessels, kidney, brain, and retina. Events tend to be rare, so most of the evidence we have is based on the use of the markers of organ damage -- such as left ventricular hypertrophy and increased urinary albumin excretion. Clinical experience shows that reducing high blood pressure in conditions such as acute heart failure, hypertensive encephalopathy, and malignant hypertension improves survival and reduces sequelae in children. There is no doubt that increased blood pressure in children can lead to serious problems.
Medscape: Does hypertension tend to be accompanied by elevated cholesterol and other risk factors? Should these be screened and treated too?
Dr. Lurbe: Risk factors include comorbidities such as elevated cholesterol. This is especially true in obese hypertensive children, and those who have a family history of cardiovascular disease.
Medscape: What portion of hypertensive children become hypertensive adults? How strong is the evidence for this?
Dr. Lurbe: The roots of hypertension in adulthood tend to extend back to the childhood years. Indeed, childhood blood pressure does continue on into adulthood. This underscores the importance of controlling blood pressure control in children and adolescents.
Medscape: Should all children be regularly screened?
Dr. Lurbe: Children older than 3 years of age who are seen in a medical setting should have their BP measured. In younger children, BP should be measured under special circumstances that increase the risk for hypertension, such as under neonatal conditions requiring intensive care, congenital heart disease, renal disease, treatment with drugs known to increase BP, and evidence of increased intracranial pressure.
Medscape: As children grow, their blood pressure changes, normally. Can you explain how values for different categories have been developed?
Dr. Lurbe: We use a chart to help determine what ranges are normal for specific age, gender, and height. The 95th percentile is used as a cut-off for defining hypertension in children and adolescents. There are normative data based on auscultatory measurements from large studies of children around the world. There are extensive data based on measurements from more than 70,000 children in the United States. Blood pressure percentiles were calculated for each gender, age group, and for 7 height percentile categories. Height percentiles are based on growth charts attained from the Centers for Disease Control and Prevention. In Europe, reference values were obtained in 1991 by pooling data from 28,043 children and adolescents using auscultatory blood pressure measurements. In 1999, normative values were calculated from auscultatory data in 11,519 school children aged 5 to 17 years in Italy - data in that project included age, gender, and height.
Medscape: Is height the most important factor?
Dr. Lurbe: The values are based on age, gender, and height. Values developed for the United States reflect all 3 criteria together, and these are found on Tables 2 and 3 of the new guidelines. The reason why blood pressure values are referred to in age, gender, and height percentiles is to take into account children who are unusually short or tall for their age.
Medscape: How should blood pressure be measured in children? Do methods change with the age of the child?
Dr. Lurbe: The diagnosis of hypertension should be based on multiple office blood pressure measurements, taken on separate occasions over time.
Medscape: Which antihypertensive agents can be used in pediatrics?
Dr. Lurbe: The agents of choice are similar to those in adults: angiotensin-converting enzyme inhibitors, angiotensin receptor antagonists, calcium antagonists, beta-blockers, and diuretics and other antihypertensive agents. There have been very few trials doing head-to-head comparisons of these agents in children.
Medscape: How strong is the evidence for their effectiveness? Are they safe?
Dr. Lurbe: Evidence for effectiveness is mostly of newer drugs, because many of the older drugs are now off-patent and studies weren't performed for the pediatric population. Recommendations in the guidelines are based primarily on a few industry-sponsored studies, and mostly case series from single centers. There is also collective clinical experience, expert opinions, and extrapolation from adult studies.
Medscape: Should doctors recommend lifestyle changes before trying drug therapy? Would lifestyle changes and weight loss be enough?
Dr. Lurbe: That might help for mild cases, but there is currently a lack of hard evidence. Studies are underway looking at lifestyle changes. With medications, generally, it is recommended that children begin with a low dose of a single drug. You don't want blood pressure to drop too rapidly. If a single drug doesn't do the trick, then combinations may be needed -- especially in severe hypertension.
Medscape: What lifestyle changes should physicians discuss with patients/parents?
Dr. Lurbe: Most interventions are common sense, such as exercise, weight loss, and a healthy diet. Some evidence suggests 40 minutes of aerobic-based exercise 3-5 times weekly improves vascular function and lowers blood pressure in children. Interventions that work together to reduce energy intake and increase activity are bound to help. Dietary trials clarifying what would work best in children are underway. Making sure diets are generally balanced, and reducing junk food is common sense.
Medscape: What does the future hold in this area?
Dr. Lurbe: A lot more research is necessary, ranging from high-quality clinical trials comparing treatments, as well as trials looking at long-term outcomes such as organ damage. There is also a need for robust values for home, office, and ambulatory blood pressure.
Medscape: You've touched on a lot of areas in the guidelines. Thanks for talking to Medscape today.