MCT1 transporter polymorphism and postoperative hyperlactataemia after major abdominal surgery

The monocarboxylate transporter 1 (MCT1) is a key mediator of lactate transport, and genetic polymorphisms may influence perioperative lactate dynamics. We investigated the association between the MCT1 rs1049434 polymorphism and postoperative lactate levels and outcomes following major abdominal surgery.

This prospective observational study included patients undergoing major abdominal surgery. Postoperative lactate trajectories were analysed using linear mixed-effects models with a random intercept for patients and fixed effects for time, genotype, and their interaction. Genotype was modelled additively, with the number of T alleles coded. The association between genotype and postoperative complications was assessed using Firth penalised logistic regression (additive model), adjusted for body mass index, mean arterial pressure, and surgery duration.

A total of 109 patients were analysed. Lactate levels increased over time in all patients, peaking 3 hours after surgery. In the mixed-effects analysis, no significant genotype-by-time interaction was observed. However, adjusted estimates suggested a consistent upward shift in lactate levels among T-allele carriers. In the multivariable analysis, the number of T alleles was associated with postoperative complications (OR 2.23, 95% CI 1.22-4.10;p = 0.009), although this finding should be interpreted with caution given the limited sample size.

The MCT1 rs1049434 polymorphism was not associated with differential lactate trajectories over time but was associated with a shift in postoperative lactate levels. These findings suggest that genetic variability in lactate transport may influence the interpretation of perioperative lactate values. The observed association with postoperative complications should be considered exploratory and requires confirmation in larger studies.

clinicaltrials.gov (ID: NCT06222021).