Abstract 082: Association Of Age And Blood Pressure Severity With ICD-10 Diagnosis Codes For Hypertension Disorders Among Youth Referred For Hypertension: Interim Analysis Of Data From Three Sites Of The Study Of The Epidemiology Of Pediatric Hypertension (SUPERHERO) Registry

Background: Secondary HTN is thought to be the main cause of HTN in young children and those with more severe HTN. However, the rising incidence of primary HTN has called this into question. Our objective was to estimate risk of secondary HTN based on ICD-10 codes due to age and BP. Methods: The SUPERHERO Registry is a multicenter retrospective cohort of youth referred to subspecialty care for HTN. Inclusion criteria were initial visit for HTN disorder (per ICD-10) from 1/1/2016-12/31/2021 and age <19 years. Exclusion criteria were pregnancy, dialysis, or transplant per ICD-10. Exposures were age and BP, including z-scores, and outcomes were primary and secondary HTN by ICD-10, all at baseline. We used unadjusted generalized linear models to estimate risk of 1) secondary vs. primary HTN and 2) kidney vs. non-kidney secondary HTN. Results: Median age was 14.2 years [IQR 10.5, 16.4], 52% (1703/3295) had obesity, 58% (1927/3295) had primary HTN, 9% (283/3295) had non-kidney secondary HTN, and 5% (171/3295) had kidney secondary HTN. Compared to youth <13 years old, adolescents had 38% lower risk of secondary vs. primary HTN (95% CL 0.53-0.74) and 23% lower risk of kidney vs. non-kidney secondary HTN (95% CL 0.61-0.98) (Table). A 1-unit higher systolic BP z-score was associated with 23% lower risk of secondary vs. primary HTN (95% CL 0.71-0.85) and 19% lower risk of kidney vs. non-kidney secondary HTN (95% CL 0.72-0.91). Conclusions: Older age was associated with greater risk of primary HTN and lower risk of secondary HTN due to kidney disease. However, worse systolic BP was associated with lower risk of secondary HTN, including due to kidney disease. Ongoing analyses are validating these findings.