Colectomy linked with greater risk of AKI, kidney failure in patients with IBD

Among patients with inflammatory bowel disease (IBD), colectomy was linked with more than doubled risk of acute kidney injury (AKI), indicating that these patients may benefit from close monitoring of kidney biomarkers, according to the authors of a Swedish cohort study.

Rates of acute kidney injury (AKI) and kidney failure are higher among patients with inflammatory bowel disease (IBD) who underwent colectomy, especially those with a total colectomy or colectomy with a prolonged stoma, new research suggests.

Investigators carried out a cohort study in Sweden using data from 82,051 individuals (mean age, 40 years; 48% women) who were diagnosed with IBD between 1965 and 2017. Participants were followed until 2019. Of the patients included, 22,598 had Crohn's disease, 47,222 had ulcerative colitis, and 12,231 had unclassified IBD. Researchers assessed incident colectomy and future risk of AKI and kidney failure, defined as a diagnosis of end-stage kidney disease or death due to chronic kidney disease. The impacts of a partial versus total colectomy and presence and duration of a stoma were also assessed. Findings were published by Clinical Gastroenterology and Hepatology on May 20.

A total of 16,479 patients underwent colectomy (7,672 partial, 8,807 total) during a median follow-up of 14 years. During this time, 2,556 AKI and 1,146 kidney failure events occurred. Analyses showed colectomy was linked with an increased relative risk of AKI (adjusted hazard ratio [aHR], 2.37; 95% CI, 2.17 to 2.58) and kidney failure (aHR, 1.54; 95% CI, 1.34 to 1.76). Risks were higher in patients with ulcerative colitis compared with patients with Crohn's disease (aHR for AKI, 2.88 [95% CI, 2.55 to 3.24] vs. 1.76 [95% CI, 1.50 to 2.07], respectively; P=0.011). However, risk of kidney events was higher across all IBD subtypes. Compared with precolectomy, patients had increased risks after partial colectomy (aHRs, 1.64 [95% CI, 1.44 to 1.86] for AKI and 1.19 [95% CI, 0.98 to 1.44] for kidney failure) or total colectomy (aHRs, 2.98 [95% CI, 2.70 to 3.28] and 1.89 [95% CI, 1.60 to 2.22], respectively; P<0.001 for both). Additional analyses indicated that up to 9% of kidney failure events during the study period could be attributable to colectomy.

To the authors' knowledge, the study is the only one to date suggesting a link between colectomy and risk of AKI and kidney failure among patients with IBD. The exact underlying mechanisms of the association are unknown, they wrote. Limitations included lack of information on medications patients took prior to 2005 and no accounting for the possibility that patients could experience multiple acute kidney injuries over time.

Overall, "as a clinical implication, patients undergoing colectomy represent a particular high-risk group that may benefit from more close monitoring of kidney biomarkers," the authors wrote. "This may help to early identify signs of kidney damage that can prompt minimizing the exposure to nephrotoxic medications, initiating antiproteinuric therapies, or timely referring to nephrological care," they concluded.