Abstract P134: Cystatin C Predicts Diastolic Dysfunction in Children with Chronic Kidney Disease, Independent of Kidney Function
Background: Cystatin C is a surrogate marker of kidney function but is also independently associated with CVD outcomes. Our aims were to (1) quantify the relationship between cystatin C and diastolic function over time among children with CKD and (2) determine if any relationship persists after accounting for kidney function.
Methods: Data from 561 participants enrolled in the Chronic Kidney Disease in Children (CKiD) cohort study were included. Participants have biennial visits with local standardized echocardiography and iohexol glomerular filtration rate (iGFR) measurements. Diastolic function was assessed centrally by E’/A’ from Tissue Doppler.
Linear mixed models, adjusting for repeated visits with a random subject effect, were used. The longitudinal association of cystatin C with change in log (E’/A’) was adjusted for age, sex, race, BMI z-score, systolic and diastolic BP z-score, Calcium*Phosphorus product and length of time with CKD. Regression coefficients were transformed and interpreted as percent change in E’/A’.
Results: At baseline, median age was 11.3 yrs (IQR: 7.9, 14.8), 38% female, and 16% AA. Median cystatin C was 1.5 mg/L (IQR: 1.2, 2.0), median GFR was 47.6 mL/min/1.73m2 (IQR: 36.5, 63.9) and median creatinine 1.2 mg/dL (IQR: 0.8, 1.6). Median E’/A’ was 1.95 (IQR: 1.5, 2.4). Cystatin C and other measures of kidney function predicted diastolic function when assessed separately (Table). When assessed together, cystatin C remained independently associated while the effect of iGFR was attenuated and insignificant.
Conclusions: Lower kidney function, as assessed by Cystatin C and other measures, is associated with diastolic dysfunction among children with mild-moderate CKD over time. However, only Cystatin C had an independent relationship with diastolic function in this patient population; the effect of iGFR was attenuated and not significant after accounting for Cystatin C. This suggests that Cystatin C has the potential to contribute to CVD risk stratification among children with CKD.
Author Disclosures: T.M. Brady: B. Research Grant; Significant; National Institutes of Health, NHLBI K23 grant award, National Institutes of Health, NIDDK R01 award Co-I, Clinician Scientist Award, Johns Hopkins University. G. Consultant/Advisory Board; Modest; National Kidney Foundation of Maryland, Medical Advisory Board Member. K.C. McDermott: None. M.F. Schneider: None. C. Cox: None. B.A. Warady: None. S. Furth: None. M. Mitsnefes: None.
- © 2015 by American Heart Association, Inc.