Predictive role of vitamin B 12 in acute kidney injury in living donor liver transplantation: A propensity score matching analysis

Objectives We examine the association between vitamin B 12 level and risk for acute kidney injury (AKI) in patients undergoing living donor liver transplantation (LDLT). Design Retrospective observational cohort study. Setting University hospital, from January 2009 to December 2018. Participants A total of 591 patients who underwent elective LDLT were analysed in this study. Those with a preoperative history of kidney dysfunction, vitamin B 12 supplementation due to alcoholism, low vitamin B 12 (<200 pg/mL) or missing laboratory data were excluded. Primary and secondary outcome measures The population was classified into AKI and non-AKI groups according to Kidney Disease Improving Global Outcomes (KDIGO) criteria, and associations between perioperative factors and AKI were analysed. After 1:1 propensity score (PS) matching, the association between high vitamin B 12 (>900 pg/mL) and postoperative AKI was evaluated. Results Preoperative vitamin B 12 was higher in the AKI group. Potentially significant perioperative factors from univariate analyses were entered into multivariate analyses, including preoperative factors (vitamin B 12, diabetes), intraoperative factors (hourly urine output) and donor graft fatty change in LDLT patients. PS matching analyses with adjustment using PS revealed that high serum vitamin B 12 (>900 pg/mL) was associated with risk for AKI, and the risk was 2.8-fold higher in patients with high vitamin B 12 than in those with normal vitamin B 12. Higher vitamin B 12 was also related to a higher AKI stage. In addition, inflammatory factors (C reactive protein, white blood cells and albumin) were associated with vitamin B 12 level. Conclusions Our study may improve the accuracy of predicting postoperative AKI by introducing preoperative vitamin B 12 into risk assessments for patients undergoing LDLT.