Abstract P392: Ambulatory Arterial Stiffness Index Among Children With Chronic Kidney Disease

Abstract

The ambulatory arterial stiffness index (AASI) is a non-invasive measure of arterial stiffness derived from ambulatory blood pressure monitoring (ABPM) data. Studies in children have shown higher AASI is associated with obesity and hypertension, but there are no data examining AASI in children with chronic kidney disease (CKD). We used data from the Chronic Kidney Disease in Children (CKiD) Cohort Study to evaluate the association between AASI and hypertensive status on ABPM, and to identify predictors of AASI, including BMI, proteinuria, mineral metabolism and BP parameters from ABPM. Of 639 CKiD participants at their first successful ABPM visit, the mean age was 12 years, 60% (382/639) were male, 15% (96/639) were obese and the mean eGFR was 52 ml/min/1.73m 2 . Approximately two-thirds reported antihypertensive therapy use (66%, 422/639) yet 58% (368/639) met criteria for abnormal ABPM (elevated mean awake/sleep DBP/SBP or awake/sleep load >25%). Participants who met criteria for abnormal ambulatory BP had a higher mean AASI than those with a normal ambulatory BP (0.337 and 0.307, respectively, p=0.008). Masked hypertension (MH) was common (42.4%, 284/639) and those subjects had a significantly higher AASI compared to normotensive children (Table). Male sex, age and BMI category were all positively associated with AASI, but presence of proteinuria, abnormal serum calcium or phosphate were not. AASI is associated with hypertensive status and BMI in children with CKD and may be a useful non-invasive measure of vascular stiffness in this population. The relationship of AASI to other measures of vascular stiffness such as pulse wave velocity requires further study.