Association between intraoperative hyperglycemia and 1-year mortality in liver transplantation: importance of pre-reperfusion period

• Intraoperative hyperglycemia was linked to increased 1-year mortality after LT. • Only pre-reperfusion hyperglycemia predicted post-transplant mortality. • Early intraoperative glycemic control may improve postoperative outcomes after LT. • Insulin-resistant hyperglycemia reflected severe metabolic stress and higher mortality. Intraoperative hyperglycemia has been associated with adverse outcomes after major surgery. However, it remains unclear whether hyperglycemia before or after graft reperfusion more strongly influences mortality following liver transplantation (LT). We conducted a retrospective cohort study of 1,068 adult patients who underwent LT at a single center between January 2012 and June 2023. Time-weighted average glucose (TWAG) levels were calculated using intraoperative arterial blood gas data. Total-TWAG was divided into pre- and post-reperfusion periods. The primary outcome was 1-year all-cause mortality. Multivariable Cox regression models were used to assess the association between TWAG and mortality after adjustment for clinically relevant covariates. The 1-year mortality rate was 7.1%. Kaplan-Meier analysis demonstrated significant differences in 1-year survival across TWAG quartiles for total- and pre-reperfusion TWAG (log-rank p=0.003 and p<0.001, respectively), but not for post-reperfusion TWAG (p=0.165). In multivariable analysis, total-TWAG was independently associated with increased 1-year mortality (HR 1.08 per 10 mg/dL increase, 95% CI: 1.02–1.15, p = 0.012). When TWAG was divided into pre- and post-reperfusion components, only pre-TWAG remained significantly associated with mortality (HR 1.07 per 10 mg/dL increase, 95% CI: 1.01–1.13, p = 0.024), whereas post-TWAG was not (HR 1.03 per 10 mg/dL increase, 95% CI: 0.98–1.09, p = 0.215). Intraoperative hyperglycemia prior to graft reperfusion was independently associated with increased 1-year mortality after LT. These findings suggest that early-phase glycemic control may play a critical role in improving postoperative outcomes.