Young adults who had undiagnosed and unmanaged high blood pressure as children face a higher risk of suffering a life-threatening heart attack or stroke as early as their late twenties or early thirties. These are people in the prime of their lives, when they’re building careers, getting married, starting families or buying their first homes, and their children are also at higher risk of developing this medical condition.

High blood pressure, also called hypertension, is present in six to eight per cent of children and is becoming increasingly common. Yet studies show it’s largely underdiagnosed. 

Hamilton Health Sciences (HHS) pediatric kidney specialist Dr. Rahul Chanchlani is concerned for the future of these young people, and he’s leading a study aimed at developing an online screening tool, or calculator, that family doctors, pediatricians and even parents can use to predict risk and intervene early, so dangerous health complications due to hypertension can be prevented.

And because the study is international in scope, this innovative screening tool will have the potential to be used worldwide, preventing life-threatening illnesses and saving health-care systems millions of dollars.

Blood pressure checks rare for kids

Chanchlani led a study that was published in the Journal of the American Medical Association (JAMA) Network Open in January. Results showed that less than 25 per cent of children have their blood pressure checked during visits to their family doctor.

Hypertension Canada guidelines recommend annual blood pressure checks for all children between the ages of three to 17, with more frequent checks for those considered at risk. Yet routine screening rarely happens at the primary care level in Canada, partly because the need had never been clearly identified. 

There’s a lack of awareness, even in medical circles, about the dangers of hypertension in children, says Chanchlani. “I’m not blaming primary care providers. Family doctors are overburdened. Regular blood pressure checks for children aren’t part of their routine practice, and they may not have blood pressure machines for kids, with the smaller sized cuffs or they may lack the nursing support to check blood pressure.”

Chanchlani runs the Pediatric Hypertension Clinic at HHS McMaster Children’s Hospital (MCH), where his patients include kids with high blood pressure for reasons including heart defects, kidney disease, genetic conditions or lifestyle issues like being overweight.

He also leads groundbreaking, award-winning research addressing the under-diagnoses of pediatric hypertension in Canada.

A study led by Chanchlani, published in JAMA Pediatrics in May, found that Canadian children diagnosed with hypertension have twice the risk of having a major heart attack, stroke or even dying as early as their late 20s or early 30s. 

Chanchlani’s research included analyzing the health records of thousands of Ontario children as far back as 1996 using data from The Institute for Clinical Evaluative Sciences of Ontario (ICES), an independent, non-profit research organization. The study tracked outcomes of more than 25,000 children diagnosed with high blood pressure, comparing them to a control group of about 120,000 children who didn’t have hypertension.

“We followed these children from 1996 to 2022, and found that those with high blood pressure were at twice the risk of having major cardiovascular events such as heart failure, heart attack or stroke within 20 years of their diagnosis.”

Chanchlani’s research aims to reduce the future adverse outcomes of hypertension by showing the huge benefits of early detection and intervention.

A preventable condition

When young children have high blood pressure, it’s often related to health conditions like heart defects or kidney disease, or some other medical conditions. But with older kids heading into their teen years, it tends to be triggered by lifestyle issues like being sedentary, overweight, obese, and/or eating too much salt. These older kids would especially benefit from a screening tool and early detection, because in their case high blood pressure can be prevented or managed when caught early.

Going back 25 or 30 years, studies show that two to three per cent of Canadian children were diagnosed with high blood pressure. Today, it’s significantly higher at six to eight per cent. And that’s likely low, because children aren’t routinely checked. In addition, one-third of Canadian children are considered overweight or obese, making them more at risk.

A new, innovative approach

Improving screening at the primary-care level is the key to identifying kids with high blood pressure early, in order to prevent serious health complications down the road. 

Chanchlani’s ALERT-BP study, made possible through funding from the HHS Foundation and Kidney Foundation of Canada, aims to develop a risk prediction tool, or calculator, for detecting high blood pressure in kids as young as five using data from birth cohort studies in Canada, the United States and the United Kingdom, and testing the prediction tool model in those countries. 

Two of the Canadian cohorts are in based in Hamilton, led by HHS physicians. The South Asian Birth Cohort (START) was led by Dr. Sonia Anand, an HHS vascular medicine specialist and senior researcher at the Population Health Research Institute, a joint institute of HHS and McMaster University. The other is the FAMILY Atherosclerosis Monitoring in Early Life study led by Dr. Katherine Morrison, a researcher and the medical director of the Pediatric Weight Management and Pediatric Lipid Clinics at MCH. 

Next steps before launching the study include receiving ethics board approval, working on data sharing agreements, recruiting a masters student with expertise in statistics and partnering with the HHS CREATE (Centre for Data Science and Digital Health) team to explore incorporating machine learning and AI when developing this risk prediction tool.

Staffed with experts in software engineering, AI and data sciences, CREATE works with hospital clinicians including physicians to develop new ideas and create digital solutions that fundamentally reimagine how health care is delivered.