Background and Aim: Hypozincemia is common in patients with liver cirrhosis; however, its impact on prognosis and the prognostic cutoff remain unclear. This study aimed to identify a prognostic serum zinc threshold using data-driven methods and to evaluate the prognostic association of zinc supplementation with overall survival (OS). Methods: Among 721 zinc treatment-naive patients with liver cirrhosis, a prognostic serum zinc threshold associated with OS was determined. OS was subsequently compared between zinc-treated and untreated patients with baseline serum zinc below this threshold. Baseline characteristics were balanced between the zinc-treated and untreated groups (n = 119 each) using propensity score matching (PSM). Results: Analyses examining the association between serum zinc levels and prognosis demonstrated a dose-dependent relationship with OS. A serum zinc level of 70 µg/dL was identified as a prognostic cutoff strongly associated with OS. Among patients with serum zinc levels <70 µg/dL after PSM, the median OS was longer in the zinc-treated group than in the untreated group (86.4 vs. 47.5 months; p = 0.034). The adjusted hazard ratio (95% confidence interval) for OS in the zinc-treated group compared with the untreated group was 0.64 (0.44–0.94). Conclusions: A prognostic serum zinc threshold was identified in patients with liver cirrhosis, and zinc supplementation was associated with improved survival. Routine monitoring and zinc supplementation to maintain levels above this reference value may contribute to better prognosis. However, due to the retrospective design and potential residual confounding, future prospective trials are required to validate these findings.
Tanaka et al. (Wed,) studied this question.