New methods of differentiation between primary and secondary hypertension in a pediatric population: A single-center experience.

Background: Kidney diseases are the main causative factors of secondary hypertension (HTN) in children. Although primary HTN is less common in the pediatric population, its increasing prevalence, especially among teenagers, makes early diagnosis an emerging issue.

Objectives: To analyze the potential differences between primary HTN and HTN secondary to renal diseases, in order to tailor diagnostic procedures to pediatric patients with suspicion of HTN.

Material And Methods: A retrospective evaluation was performed of medical records of 168 children (aged from 1 month to 18 years) diagnosed with arterial HTN in the Pediatric Nephrology Department of Wroclaw Medical University (Poland). The comparative analysis concerned demographics, causes of HTN, clinical picture, laboratory tests, and parameters of ambulatory blood pressure monitoring (ABPM).

Results: Out of 168 children, 47% were diagnosed with primary HTN and 53% with secondary renal HTN. The patients with primary HTN were significantly older than those with HTN secondary to renal disease. Among the children with primary HTN, 26% were overweight and 42% were obese; among those with renal HTN, the proportions were 16% and 19%, respectively. The patients with primary HTN had significantly higher body mass index (BMI) percentiles and z-scores, and tended toward higher pulse pressure (PP) values. In the group with secondary HTN, ABPM parameters of diastolic blood pressure (DBP) and total cholesterol were significantly elevated. The BMI z-scores correlated positively with PP in the whole group.

Conclusions: As expected, HTN secondary to renal disease prevails in younger children, but primary HTN has become an emerging issue in teenagers. The diagnostics of HTN secondary to kidney disease have revealed risk factors worsening the prognosis, including higher values of cholesterol or of parameters connected with DBP. Primary HTN risk factors include obesity and a tendency towards higher PP values.