422 - Association of Childhood Blood Pressure Dipping with Target Organ Injury

Publication Number: 1405.422

Andrew H. Tran, Nationwide Children's Hospital, Columbus, OH, United States; Elaine Urbina, Cincinnati Children's Hospital Medical Center, Cincinnati, OH, United States; Carson Richardson, Nationwide Children's Hospital, Columbus, OH, United States; Joseph Flynn, Seattle Children's, Seattle, WA, United States

Background: Nocturnal blood pressure (BP) dipping is the typical decrease in BP during sleep with the usual BP decrease ranging between 10-20%. Non-dipping occurs if the systolic BP (SBP) or diastolic BP (DBP) decrease is < 10% and is associated with increased risk for adverse cardiac events in adulthood. In children, non-dipping has been associated with increased left ventricular mass, proteinuria, and progression of kidney disease. However, non-dipping has primarily been studied as a dichotomous variable (e.g., non-dipping vs normal dipping) and data are limited on the per unit association of BP dipping and target organ injury (TOI) in children.

Objective: To evaluate the association of blood pressure dipping as a continuous variable on target organ injury in children.

Design/Methods: This was a cross-sectional study of youth aged 11-19 years enrolled in the Study of High Blood Pressure in Pediatrics: Adult Hypertension Onset in Youth study. Participants were categorized by BP into low-risk (SBP < 75th percentile), moderate-risk (SBP ≥80th and < 90th percentile), and high risk (SBP ≥90th percentile) groups. Multi-variable linear regression models were used to evaluate the association between SBP/DBP dipping and measures of TOI. Adjusted estimates are presented for both overall associations and associations by BP risk category.

Results: There were 347 participants in the study (Table 1: N=137 low-risk, N=86 moderate-risk, N=124 high-risk; mean age 15.6 years [SD 1.7]; 41% female). There was a progressive increase in BMI percentile across BP risk groups─ highest in the high-risk group. SBP and DBP dipping were similar across groups. On multivariable linear regression analyses, there was no significant association between SBP or DBP dipping and left ventricular mass index (LVMI), estimated glomerular filtration rate (eGFR), or urine albumin/creatinine ratio (UACR). However, there was a significant association between SBP dipping in the moderate-risk group and left ventricular peak global longitudinal strain (GLS; Figure 1; β = -0.19 [95% CI -0.35, -0.03], p=0.020). This was also evident with DBP dipping and GLS in the moderate-risk group (Figure 2; β = -0.21 [95% CI -0.33, -0.09], p< 0.001).

Conclusion(s): BP dipping was not associated with LVMI, eGFR, or UACR. However, greater BP dipping was associated with improvements in left ventricular peak GLS in the moderate-risk group for both SBP and DBP dipping. Additional investigation is needed to further clarify the association between BP dipping and TOI in children.

Table 1. Participant characteristics
ABPM = ambulatory blood pressure monitor; BMI = body mass index; LVMI = left ventricular mass index

Figure 1. Multivariable linear regression and plot of association between SBP dipping and left ventricular peak global longitudinal strain (GLS) by BP risk group
Measurements of left ventricular peak global longitudinal strain (GLS) were measured in the 4 chamber (4 ch) view.
BP = blood pressure; SBP = systolic blood pressure


Figure 2. Multivariable linear regression and plot of association between DBP dipping and left ventricular peak global longitudinal strain (GLS) by BP risk group
Measurements of left ventricular peak global longitudinal strain (GLS) were measured in the 4 chamber (4 ch) view.
BP = blood pressure; DBP = systolic blood pressure