Serum Zinc Level Classification System: Usefulness in Patients with Liver Cirrhosis

Currently, the Japanese society of clinical nutrition (JSCN) defines serum zinc (Zn) level < 60 μg/dL as Zn deficiency and 60 μg/dL ≤ serum Zn level < 80 μg/dL as subclinical Zn deficiency, and 80 μg/dL ≤ serum Zn level < 130 μg/dL as normal Zn range. We aimed to elucidate the prognostic impact of this Zn classification system in patients with liver cirrhosis (LC) compared to the Child–Pugh classification and the albumin–bilirubin (ALBI) grading system (n = 441, median age = 66 years). The Akaike information criterion (AIC) with each evaluation method was tested in order to compare the overall survival (OS). The median serum Zn level was 65 μg/dL. There were 56 patients with normal Zn level, 227 with subclinical Zn deficiency and 158 with Zn deficiency. OS was well stratified among three groups of serum Zn level (p < 0.0001). The AIC value for survival by the Zn classification system was the lowest among three prognostic models (AIC: 518.99 in the Child–Pugh classification, 502.411 in ALBI grade and 482.762 in the Zn classification system). Multivariate analyses of factors associated with OS revealed that serum Zn classification by JSCN was an independent factor. In conclusion, the serum Zn classification proposed by JSCN appears to be helpful for estimating prognosis in LC patients.