Association of serum lactate levels measured immediately before hemodialysis initiation with all-cause mortality in patients with end-stage kidney disease

Serum lactate levels are a prognostic factor in patients with critical illnesses, sepsis, and cardiac diseases. However, their prognostic significance in patients initiating hemodialysis remains unclear. Therefore, we aimed to clarify the association between serum lactate levels at the initiation of hemodialysis and mortality in end-stage kidney disease. In this retrospective cohort study, we included patients who initiated hemodialysis at the Nagasaki Harbor Medical Center between 2016 and 2023 with follow-up to 2024. Patients were divided into high- and non-high-lactate groups based on the third quartile of serum lactate levels (12 mg/dL). Mortality rates and factors affecting serum lactate levels were assessed. In total, 261 patients were included (72.0 ± 11.7 years; men, 65.6%; median [interquartile range] serum lactate levels, 9 [7−12] mg/dL). All-cause mortality was higher in the high-lactate group (≥ 12 mg/dL) than in the non-high-lactate group (< 12 mg/dL). In the fully adjusted Cox model, each 1-mg/dL increase in serum lactate was associated with higher all-cause mortality (HR, 1.09; 95% CI, 1.04–1.13). Serum lactate levels were also associated with ischemic heart disease ( p < 0.01). Serum lactate levels at the time of initiating hemodialysis were associated with all-cause mortality in patients with end-stage kidney disease. Elevated serum lactate levels were also statistically associated with ischemic heart disease at the time of initiating hemodialysis. These findings should be interpreted with caution because of the retrospective observational design, and prospective studies are needed to confirm their clinical significance.