Abstract
Circulating citrate may serve as a proxy for mitochondrial dysfunction which plays a role in the progression of end-stage liver disease (ESLD). This study aimed to determine the extent of alterations in circulating citrate in patients with ESLD, and examined its association with all-cause mortality among ESLD patients while on the waiting list for liver transplantation. Plasma citrate levels were measured using nuclear magnetic resonance spectroscopy in 129 ESLD patients (TransplantLines cohort study; NCT03272841) and compared to levels in 4837 participants of the community-dwelling PREVEND cohort. Plasma citrate levels were 40% higher in ESLD patients compared to PREVEND participants (p < 0.001). In a subset of 30 ESLD patients, citrate decreased following liver transplantation (p < 0.001), resulting in levels that were slightly lower than those observed in PREVEND participants. In multivariable analysis, plasma citrate levels were positively associated with Child-Turcotte-Pugh classification and inversely associated with estimated glomerular filtration rate (both p < 0.05). Survival was significantly reduced in ESLD patients in the highest citrate tertile (log-rank p = 0.037). Elevated citrate levels were associated with an increased risk of all-cause mortality in ESLD patients (HR per 1 Ln SD increment: 1.65 [95% CI: 1.03-2.63], p = 0.037). This association was suggested to be particularly present in men (HR: 2.04 [95% CI: 1.08-3.85], p = 0.027). In conclusion, plasma citrate levels are elevated in ESLD patients and decrease following liver transplantation. Moreover, elevated plasma citrate levels may be associated with increased all-cause mortality in ESLD patients, likely more pronounced in men.