Correlation of serum zinc levels with pathological and laboratory findings in patients with nonalcoholic fatty liver disease

Objective Chronic liver diseases are associated with zinc (Zn) deficiency. However, no previous studies have examined the relationship between serum Zn levels and hepatic pathological findings in patients with nonalcoholic fatty liver disease (NAFLD). The aim of this study was to investigate the serum Zn levels in NAFLD patients based on pathological/laboratory findings. Methods We evaluated a total of 191 NAFLD patients who underwent liver biopsy with the goal of identifying laboratory markers and pathological findings associated with serum Zn levels. Results Zn levels significantly decreased along with progression of hepatic fibrosis (P = 0.039), but there were no significant differences among inflammatory grades. Zn levels were most strongly correlated with albumin levels (r = 0.410, P < 0.001). In addition, Zn levels were significantly correlated with homeostasis model assessment of insulin resistance (HOMA-IR) (r = -0.284, P < 0.001), hyaluronic acid (r = -0.230, P < 0.001), branched chain amino acid/tyrosine molar ratio (BTR) (r = 0.278, P < 0.001), FIB-4 index (r = -0.238, P < 0.001), and NAFLD fibrosis score (NFS) (r = -0.261, P < 0.001). In multivariate analysis, albumin [odds ratio (OR), 9.244 (per 1 g/dL decrease) [95% confidence interval (CI), 2.261-32.744]; P < 0.001], BTR [OR, 1.545 (per 1 decrease) (95% CI, 1.115-2.140); P = 0.009], and HOMA-IR [OR, 1.048 (per 1 increase) (95% CI, 1.019-1.167); P = 0.028] were significantly associated with Zn deficiency. Conclusion The progression of liver fibrosis, but not inflammation, is associated with lower serum Zn levels in biopsy-proven NAFLD patients. Serum Zn levels were correlated with nutrition markers and insulin resistance.