Characteristics of pediatric inpatients with primary and secondary hypertension.

Importance Extensive population-based studies have explored the prevalence of primary hypertension (HTN) in children and adolescents. However, there is little published data on the characteristics of different types of pediatric HTN and the causes of secondary HTN. Objective To investigate the characteristics of different types of pediatric HTN and the causes of secondary HTN in a hospital setting. Methods The study cohort comprised pediatric inpatients (<18 years of age) discharged with a diagnosis of HTN from Beijing Children's Hospital during 2015-2020. Pediatric patients with HTN were allocated to secondary and primary HTN groups on the basis of comprehensive analyses of their diagnoses, family history of HTN, and findings on physical examination, as documented in their medical records. The Mann-Whitney U test, χ2 and Fisher's exact test were used to assess differences in characteristics of patients with different HTN types and causes of secondary HTN. Results Data of 1470 inpatients with HTN from 18 clinical departments were included in the analysis. Among them, 458 (31.2%) had primary HTN, and 1012 (68.8%) had secondary HTN. Compared with patients had primary HTN, children with secondary HTN were younger and had lower body mass indexes and longer lengths of stay. Moreover, children with primary HTN had mostly been managed by the Endocrinology and Cardiology Departments, 75.8% of them having obesity-related comorbidities. In contrast, most patients with secondary HTN had been managed by the Nephrology Department, renal diseases being the leading cause of their HTN (46.3%). Interpretation Secondary HTN is more common than primary HTN in pediatric clinical settings, renal diseases being the leading cause of secondary HTN.