Checking kidney function is important during the course of IBD

Nearly 12% of patients with inflammatory bowel disease (IBD) develop deterioration of kidney function within 10 years of IBD diagnosis. However, an ICD-code for chronic kidney disease was only present in 6.4% at this timepoint.

A Swedish, observational, cohort study used the healthcare utility database SCREAM to evaluate kidney-related complications in patients with IBD, a topic with insufficient scientific results to date [1]. Around 1.7 million people without IBD who had baseline values of an estimated glomerular filtration rate (eGFR) on file as of 2006 were followed until death, emigration, or the end of 2019. The primary composite outcome was any kind of chronic kidney disease (CKD) events and consisted of a ≥30% decrease in eGFR or kidney failure subsumed as CKD progression. To calculate absolute risks, cases of incident IBD within the follow-up period were matched with up to 5 controls from the reference population.

“After a median follow-up of 9 years we observed about 10,000 IBD cases, which is about 0.6% of the entire cohort,” Dr Yuanhang Yang (Karolinska Institutet, Sweden) stated. Within 10 years after an IBD diagnosis, 11.8% of the patients developed CKD. This corresponded to a 25% increased relative risk of the primary outcome. Of note, only 6.4% had received a diagnosis (ICD code 10) for CKD at the 10-year follow-up. The adjusted hazard ratio (HR) of CKD progression was 1.11 (P=0.041). In addition, the relative risks for acute kidney injury, kidney stones, and secondary amyloidosis were significantly elevated with an HR of 1.97, 1.69, and 2.77, respectively.

When differentiating according to an IBD diagnosis of either Crohn’s disease (CD) or ulcerative colitis (UC), the relative risk of having any kind of CKD event was higher for those with CD: HR 1.40 for CD versus 1.10 for UC. “We also did a subgroup analysis between men and women and we found no major difference,” Dr Yang added.

Dr Yang underlined that a higher risk of acute kidney injury has not been previously recognised in the literature. “Our findings bring to attention that we need to establish protocols for kidney function monitoring, and, of course, referral to nephrological care for IBD patients,” Dr Yang concluded.

1. Yang Y. Absolute and relative risks of kidney and urological complications in patients with inflammatory bowel disease. OP07, ECCO 2023, 01–04 March, Copenhagen, Denmark.

Posted on 4 May, 2023