46 - Burden of kidney dysfunction over time in children with inflammatory bowel disease

Recent studies in patients with inflammatory bowel disease (IBD) have demonstrated an increased risk of chronic kidney disease (CKD). The burden of kidney dysfunction in pediatric IBD has not been well quantified.

Objective:

To evaluate the burden of kidney dysfunction in children with IBD at time of last follow-up in a large inception cohort and identify risk factors for development of kidney dysfunction.

Design/Methods:

This was a retrospective cohort study using the Crohn’s & Colitis Foundation Pediatric RISK Stratification Study, a prospective inception cohort of children with IBD. Participants were excluded if they did not have serum creatinine or height data available to calculate estimated glomerular filtration rate (eGFR) at enrollment and at ≥1 follow-up visit. The primary outcome was kidney dysfunction, defined as eGFR < 90 mL/min/1.73m² (calculated using the Chronic Kidney Disease in Children (CKiD) Under 25 estimating equation) at time of last follow-up with available eGFR data. Logistic regression was used to evaluate the association between covariates of interest and the primary outcome.

Results:

Of 1,404 total RISK participants with IBD, 1,124 had eGFR data available at enrollment. Baseline data for this subset was previously reported. 904 additionally had follow-up eGFR data available and were included in this study. 81.4% (n=736) had Crohn’s disease (CD), 13.4% (n=121) had ulcerative colitis (UC) and 5.2% (n=47) had IBD-unclassified (IC). 39.9% (n=361) were female. The median age of diagnosis was 12 years (IQR 10-15). Median follow-up time was 44 months (IQR 27-58). 16.5% (n=149) had kidney dysfunction at last follow-up with median eGFR 82.2 mL/min/1.73m² (IQR 76.0-86.2). Older age [Odds Ratio (OR) 1.11 95% Confidence Interval (CI) 1.04-1.18], female sex [OR 1.60 95% CI 1.08-2.36], and UC diagnosis [OR 1.80 95% CI 1.04-3.13] were significantly associated with increased risk of kidney dysfunction at last follow-up in multivariable analysis. Higher eGFR at enrollment [OR 0.95 95% CI 0.94-0.96] was significantly associated with a decreased risk of kidney dysfunction at last follow-up. Specific medication exposures and presence of ileocolonic disease were not associated with kidney dysfunction at last follow-up [Table 1]. 

Conclusion(s):

This study demonstrated a significant burden of kidney dysfunction in children with IBD. Older age, lower eGFR at enrollment and female sex were risk factors for developing kidney dysfunction in this population. These results highlight the importance of recognizing and monitoring for kidney dysfunction after IBD diagnosis.
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