Effect of zinc supplementation on atherogenic risk indices in patients with non-alcoholic fatty liver disease: a randomized, double-blinded, placebo-controlled clinical trial.

Background: Zinc (Zn) deficiency is common in non-alcoholic fatty liver disease (NAFLD) patients, and this trace element plays an essential role in lipid profile control. The atherogenic index of plasma (AIP), atherogenic coefficient (AC), Castelli risk index I, and Castelli risk index II predict atherogenic statuses. This study aimed to evaluate the effect of Zn supplementation on atherogenic indices in NAFLD patients.

Methods: In this 8-week randomized, double-blinded, placebo-controlled clinical trial 50 overweighed or obese individuals suffering from NAFLD were randomly allocated into 2 groups of 25. In addition to a balanced energy-restricted diet and physical activity recommendations, participants were assigned to receive either 30 mg/d Zn or a placebo in the intervention or control group, respectively.

Results: The mean differences for energy (P = 0.761), protein (P = 0.373), fiber (P = 0.799), and zinc (P = 0.653) intakes were not statistically significant. In contrast, the mean differences for daily carbohydrate consumption (P = 0.011) and fat intake (P < 0.001) were significantly different between groups. After the study, the between-group comparisons revealed that the reduction in Castelli risk index II (P = 0.034) was significant; however, no significant differences were found for AIP (P = 0.103), AC (P = 0.113), or Castelli risk index I (P = 0.113).

Conclusion: Based on the results, supplementation with 30 mg/d Zn for 8 weeks may significantly reduce the Castelli Risk Index II, a potential marker of cardiovascular risk, and decrease CVD risk, but further studies with larger sample sizes or longer intervention durations are suggested.

Trial registration: The trial was retrospectively registered at IRCT.ir as IRCT20191015045113N1 (December/8/2019).