263 - Direct Effect of Obesity on Target Organ Injury and Indirect Effect Mediated through Blood Pressure at Baseline

Saturday, April 29, 2023

3:30 PM – 6:00 PM ET

Poster Number: 263
Publication Number: 263.251

Asmaa Semrin, Medical College of Georgia, Augusta University, Evans, GA, United States; Shupti Biswas, Cohen Children's Medical Center, Floral Park, NY, United States; Aaron M. Bridges, Wake Forest School of Medicine of Wake Forest Baptist Medical Center, Wilkesboro, NC, United States; Lucy D'Agostino McGowan, Wake Forest University, Winston Salem, NC, United States; Victoria Giammattei, Wake Forest School of Medicine of Wake Forest Baptist Medical Center, winston-Salem, NC, United States; Margret Kamel, Emory University School of Medicine, Atlanta, GA, United States; Stefan G. Kiessling, Kentucky Children's Hospital, Lexington, KY, United States; Jackson T. Londeree, Emory, Atlanta, GA, United States; Caroline B. Lucas, Wake Forest School of Medicine of Wake Forest Baptist Medical Center, Winston-Salem, NC, United States; Jason Misurac, University of Iowa Stead Family Children's Hospital, Iowa City, IA, United States; Margaret Murphy, University of Kentucky College of Medicine, Lexington, KY, United States; Sandeep Riar, Emory University School of Medicine, Atlanta, GA, United States; Christine Sethna, Cohen Children’s Medical Center, New Hyde Park, NY, United States; Irina Viviano, Wake Forest School of Medicine of Wake Forest Baptist Medical Center, Winston-Salem, NC, United States; Donald J. Weaver, Levine Children's Hospital, Charlotte, NC, United States; Ikuyo Yamaguchi, Oklahoma Childrens Hospital at OU Health, Oklahoma city, OK, United States; Emily J. Yun, Emory SOM, Atlanta, GA, United States; Andrew M.. South, Wake Forest School of Medicine of Wake Forest Baptist Medical Center, Winston Salem, NC, United States

Presenting Author(s)

Asmaa Semrin, MD, MS (she/her/hers)

Pediatric Resident PGY2
Medical College of Georgia, Augusta University
Evans, Georgia, United States

Background: Hypertension (HTN) disorders in youth can lead to target organ injury (TOI), which can start as early as the index visit. Heart-specific TOI such as left ventricular hypertrophy, the main marker of TOI, is common in youth with HTN and is a major prognostic factor for cardiovascular morbidity and mortality in adults. However, obesity may also contribute to TOI, but the effects on TOI due to obesity vs. the effects due to blood pressure (BP) have not been delineated.

Objective:

Our objective was to estimate the direct effect of obesity on TOI and the indirect effect mediated through BP severity in youth with HTN disorders.

Design/Methods:

This is an analysis of baseline data from a multisite retrospective cohort of youth referred for HTN disorders to subspecialists who are enrolled in the Study of the Epidemiology of Pediatric Hypertension (SUPERHERO) Registry. Inclusion criteria include participants aged 0-18 who were referred for their initial visit to a subspecialty clinic for HTN disorders. Exclusion criteria include participants with a history of active pregnancy, kidney transplantation, or kidney failure on dialysis. Data were collected via electronic health record queries. We defined our exposures as body mass index (BMI), BMI z-score, and obesity (BMI ≥95^th %ile for age and sex). We defined our mediators as BP, BP z-score, and HTN (per age, sex, and height-based U.S. guidelines). We defined our outcome as ICD-10 codes for HTN-related TOI in the heart. We used multivariable logistic regression models and causal mediation analysis with a directed acyclic graph-informed adjustment set containing insurance status.

Results:

Of the 5328 youth, 45% had obesity, median age was 13.8 years (IQR 9.4, 16.2), 34.8% were female, and the majority were non-Hispanic (81.2%). Obesity was associated with greater odds of TOI (OR 1.57, 95% CI 1.07, 2.28). Causal mediation analysis revealed that 95.8% (95% CI 60.5, 131.1) of the total effect of adiposity on TOI was directly due to adiposity. There was minimal evidence of appreciable mediation or interaction through BP severity (Table 1).

Conclusion(s): Youth with obesity who were referred for HTN disorders to subspecialty clinics had greater odds of having heart-specific TOI at their index visit. Adiposity was responsible for the vast majority of the total effect on TOI in the heart compared to BP severity. Our results provide more evidence for the importance of primordial prevention strategies aimed at preventing and treating obesity in youth, which may have a greater effect on reducing future cardiovascular morbidity and mortality compared to blood pressure control.