New evidence underscores the importance of tests to identify secondary causes of pediatric hypertension (high blood pressure) – a large portion of which may be related to kidney complications. The results, published in Pediatric Nephrology, emphasize the value of kidney ultrasounds for children with hypertension.
Hypertension is often due to a person’s family history or obesity. However, there is also a wide range of secondary causes. Identifying and treating one or more causes is important, especially in children who may go on to develop more health complications in adulthood if their hypertension goes untreated.
Dr. Janis Dionne is a researcher at BC Children’s Hospital Research Institute who is working on creating a provincial clinical pathway for assessing hypertension in children. “When it came to figuring out the right tests to do, the evidence was really limited,” she explains. “We wanted to look at our own data to make sure we were making the right recommendations.”
Therefore, Dionne and her colleagues analyzed data capturing 169 children who were treated for hypertension at an out-patient clinic in British Columbia between 2000 and 2015. They looked at a multitude of different test results, and the final diagnosis given to children – whether they had “primary hypertension” due to family history or obesity or “secondary hypertension” caused by a different, underlying health issue.
The results show that more than half of children had secondary hypertension, at 56 percent, and among these children, 49 percent had hypertension caused by a kidney-related complication. Ultrasounds of the kidney were found to be a particularly effective way to identify underlying causes of hypertension, for example in diagnosing kidney scarring, atrophy, congenital anomalies of kidney and urinary tract, cystic kidney diseases, and renal artery stenosis.
Dionne says these results are gaining a lot of attention from experts in the field, especially since they counteract some key recommendations in existing guidelines. For example, American pediatric guidelines currently do not recommend kidney ultrasounds for children over the age of six with hypertension, whereas the results of this study suggest such tests would be beneficial for many children of all ages with hypertension.
Of note, half of the children in this study with obesity also had a secondary condition that could cause hypertension and would benefit from treatment related to that secondary cause.
Dionne’s team is using these findings to inform their new clinical pathway, which will aim to recommend more appropriate tests for children with hypertension (e.g., more kidney ultrasounds, less bloodwork), while reducing the number of unnecessary tests and associated health-care costs.
Related Editorial: Diagnostic evaluation of the hypertensive child
