Why Pediatric Hypertension Is Underdiagnosed and Untreated

Nearly half of adults with hypertension (HTN) are not aware of their diagnosis. But recognition is even worse in pediatric patients.

“Less than 25% of children with hypertension get a diagnosis, and of those who get a diagnosis, 50% of those children are not receiving any intervention,” said Abbas H. Zaidi, MD, a pediatric cardiologist serving as the medical director of the outpatient cardiology department at Nemours Children’s Health in Wilmington, Delaware.

Studies estimate that 3%-5% of kids suffer from the condition, which has been associated with cardiovascular and renal disease in adulthood.

Zaidi wanted to get to the root of the problem. “Studies have focused on physician workflows and their challenges, but there’s not a lot of literature on what people think about this diagnosis — what are their knowledge, perceptions, and behavior?”

To address this knowledge gap, Zaidi and his colleagues conducted detailed phone interviews with 13 parents and 25 pediatric providers (either physicians, nurse managers, medical assistants, nurses, or advanced practice nurses) of patients aged 6-17 years seen at Nemours Children’s Health in Delaware and Pennsylvania between 2022 and 2023. Despite documentation of stage II HTN (defined as blood pressure [BP] > 95th percentile by age, weight, and height plus 12 mm Hg for either systolic BP [SBP] or diastolic BP [DBP], or > 140/90) on two occasions, none of these patients had received any follow-up for their HTN in the subsequent year. The study results were published in JAMA Network Open.

Zaidi and his colleagues were surprised to learn that the parents were quite knowledgeable about the importance of treating HTN — how it can be a silent killer and damage end organs including the cardiovascular system — by drawing on their own personal and family experiences with adult HTN.

“However, there was mutual skepticism regarding their child — from both parents and clinicians. High blood pressure in children was often attributed to measurement errors or white-coat hypertension,” said Zaidi. “This shared doubt created a significant barrier to addressing the issue with the urgency it requires.”

The study also found that parents were primarily worried about the potential side effects of medication and expressed concerns about their children being too young to start taking medications. “They also feared the long-term consequences of starting treatment so early in life,” stated Zaidi. “These concerns and skepticism about whether the diagnosis was accurate created significant hesitation.”

Getting the Diagnosis Right

Joseph Flynn, MD, the lead author on the most recent American Academy of Pediatrics (AAP) guidelines for screening and management of pediatric HTN, is very familiar with the problem of underdiagnosis and lack of follow-up. “It’s quite frequent that by the time they get to me, they’ve had high blood pressure readings documented for several years,” said Flynn, who is a professor of pediatrics at the University of Washington and member of the Division of Nephrology at Seattle Children’s Hospital, both in Seattle.

“To me, the fundamental issue is getting blood pressure measured more accurately in the primary care setting,” stated Flynn. “If you have a blood pressure measurement you can trust, then you actually would need to act on it and not dismiss it.”

Flynn emphasized the importance of using proper technique to obtain BP: Use an appropriate-sized cuff (the bladder length should be 80%-100% of the circumference of the arm, and the width should be at least 40%) and have the child seated with the back supported and the feet uncrossed on the floor.

On the first visit with an elevated measurement, BP should be measured in both arms and one leg in the supine position to rule out aortic coarctation. And, ideally, the child would be seated in a quiet room for 3-5 minutes before measurement. But Flynn admitted that while those are straightforward things, they do take more time.

In addition to the time constraints of good measurement technique, developing familiarity with Tables 4 and 5 from the AAP guidelines, which show the SBP and DBP levels that are considered elevated by age, height, and sex, is daunting.

“My EHR [electronic health record] does not flag high blood pressure, which is a major issue,” said Karalyn Kinsella, MD, a member of the board of editors for Pediatric News who practices at Pediatric Associates of Cheshire in Cheshire, Connecticut. “It’s obvious when it’s over 120/80, but the norms for blood pressure for a 6-year-old are very different.”

When an elevated BP is detected, Kinsella repeats it at the end of visit, when kids might be less nervous about the encounter. If it remains elevated at that point, she has them return for follow-up measurements.

Although the AAP guidelines (see Table) suggest that children with elevated BP or stage I HTN return for two more additional measurements (and one additional measurement for stage II HTN) to confirm the diagnosis, repeated trips to the office pose a barrier. Parents need to take off work and children miss school.

Kinsella’s solution is to arrange for follow-up measurements to be done by a school nurse, which also offers the advantage of having the measurement performed in a setting that is more comfortable for kids.

Zaidi would also like to see repeat measurement done outside of the clinic, such as in school or at home. Given that parents may be concerned about inaccurate readings, Zaidi feels that having the kids come back to the same clinic for a repeat measurement reinforces their belief that the clinic is getting it wrong. “The priority should be to have that blood pressure measured outside of the clinic setting,” he stated. “Families want to see the blood pressure done in different settings to restore trust in the system again.”

Options include ambulatory BP monitors (fully automated devices that can obtain BP readings for a 24-hour period) or home BP monitors (automated devices that can be used by patient or parent periodically). Although the AAP guidelines do not endorse the use of home BP monitors for the initial diagnosis of HTN, European guidelines published in 2022 recognize a potential role for home BP assessment using devices approved and validated in children.

Flynn suggested that simplifying the pediatric HTN guidelines could be helpful. “I think there’s work to do in terms of the next iteration of any guideline for childhood hypertension,” he stated. One way to streamline the diagnostic process for families and clinicians is to reduce the number of repeat measurements necessary to confirm the diagnosis. Adult guidelines in the United States require only two BP measurements, and recent European guidelines also lowered the standards for pediatric patients to two readings.

Another strategy is to simplify the pediatric BP tables so that frontline staff can easily determine whether their reading was abnormal. Flynn pointed out that the current guidelines do provide a simplified table (Table 6): It lists 90th percentile of BP values for each age and sex for kids at the 5th percentile of height (BPs are higher for taller children). This tool has a sensitivity of 100% and is designed to flag children for further evaluation. “Now that could be further refined by collapsing all of those numbers into fewer numbers,” suggested Flynn.

What Should Pediatric Providers Do After Confirming the Diagnosis?

Primary HTN generally occurs in kids older than 6 years who have either overweight or obesity with a family history of HTN. These patients generally do not require extensive evaluation for secondary causes of HTN if their history and physical exam do not suggest a secondary cause, such as renal, cardiac, or endocrine disease. But a child with HTN can be intimidating for primary care clinicians, especially for a younger child who may have secondary HTN, which has an extensive differential.

“The problem is, you honestly don’t see it all that much,” said Kinsella. “How much of this workup should I do, or should I refer to a specialist who does this more than me?” She makes sure that the patient doesn’t exhibit any signs or symptoms of HTN that might require an urgent referral and often obtains initial lab studies, but doesn’t feel confident about next steps, such as when to order a renal ultrasound.

“I think primary care providers could do the initial screening lab studies — they are basic tests that every primary care provider is familiar with,” said Flynn. For any child with elevated BP, the basic lab workup includes a urinalysis, chemistry panel (including electrolytes, blood urea nitrogen, and creatinine), and a lipid profile.

Flynn feels that subspecialists can take the burden of talking about antihypertensive medication with parents off the shoulders of pediatricians. “That’s my role as the specialist to bring a different perspective and information to bear on the conversation,” he added.

Counseling the families of every child with a BP above the 90th percentile about diet and exercise is critical, but Flynn also made it clear that medication should not be deferred for children with stage I or II HTN. High BP in children has been linked to subclinical cardiovascular disease as children, and HTN as adults; HTN in children with chronic kidney disease puts them at higher risk for kidney failure.

Zaidi wants to raise awareness that pediatric HTN is a real issue with long-term cardiovascular implications.

“It’s critical to understand the context in which we’re detecting and managing this condition, integrating the viewpoints of parents, clinicians, healthcare systems, and leaders,” he said. “We need to work together as a community to address these challenges and improve our systems.”

Zaidi’s work was supported by grant 5K12HS026393-04 from the Agency for Healthcare Research and Quality through the PEDSnet Scholars Program. Flynn and Kinsella reported no financial conflicts of interest.

A former pediatrician and disease detective, Ann Thomas is a freelance science writer living in Portland, Oregon.