1.
Role of zinc supplementation in the management of chronic liver diseases: A systematic review and meta-analysis.
Diglio, DC, Fernandes, SA, Stein, J, Azeredo-da-Silva, A, de Mattos, AA, Tovo, CV
Annals of hepatology. 2020;(2):190-196
Abstract
INTRODUCTION AND OBJECTIVES Zinc deficiency has been associated with poor prognosis in chronic liver disease. This systematic review and meta-analysis aimed to evaluate the role of zinc supplementation in the management of chronic liver diseases. MATERIALS AND METHODS We searched MEDLINE, LILACS, EMBASE, and Cochrane CENTRAL databases from inception to August 2018. We included randomized controlled trials evaluating adult patients with chronic liver disease of any etiology receiving zinc supplementation. Studies with other designs or evaluating chronic conditions other than liver disease were excluded. Two reviewers independently screened and extracted data from eligible studies. Study quality was assessed using the Cochrane Collaboration's tool for assessing risk of bias in randomized studies. RESULTS Of 1315 studies screened, 13 were included. Six assessed chronic hepatitis C treatment, with a relative risk of 0.83 indicating no protective effect of zinc supplementation on the improvement of sustained virological response. Three evaluated response to hepatic encephalopathy treatment, with a relative risk of 0.66 indicating a favorable effect of zinc supplementation on clinical improvement of this condition. Of four studies evaluating the management of cirrhosis, two analyzed the effect of zinc supplementation on serum albumin levels, with no statistical difference between zinc and placebo groups. CONCLUSIONS Clinical trials assessing zinc supplementation in liver diseases do not show benefits in terms of clinical improvement or disease halting. There are possible benefits of zinc supplementation on hepatic encephalopathy, however, this is based on limited evidence. This research question is still open for evaluation in larger, well-designed, clinical trials.
2.
Efficacy of vitamin D supplementation in combination with conventional antiviral therapy in patients with chronic hepatitis C infection: a meta-analysis of randomised controlled trials.
Kim, HB, Myung, SK, Lee, YJ, Park, BJ, ,
Journal of human nutrition and dietetics : the official journal of the British Dietetic Association. 2018;(2):168-177
Abstract
BACKGROUND Although a contributory role of vitamin D levels for the development of chronic hepatitis C has been suggested, the efficacy of vitamin D supplementation in combination with conventional antiviral therapy consisting of pegylated interferon-α (Peg-IFN-α) injection and oral ribavirin (RBV) remains unclear. We investigated its efficacy in the treatment of chronic hepatitis C via a meta-analysis of randomised controlled trials. METHODS We searched PubMed, EMBASE, the Cochrane Library, ClinicalTrials.gov and the bibliographies of relevant articles to locate additional publications in September 2016. Three evaluators independently reviewed and selected eligible studies based on predetermined selection criteria. RESULTS Of 522 articles meeting our initial criteria, a total of seven open-label, randomised controlled trials involving 548 participants, were included in the final analysis. Vitamin D supplementation in combination with Peg-IFN-α injection and oral RBV significantly increased the rate of viral response for hepatitis C at 24 weeks after treatment in a random-effects meta-analysis (relative risk = 1.30; 95% confidence interval = 1.04-1.62; I2 = 75.9%). Also, its significant efficacy was observed in patients with hepatitis C virus genotype 1, which is known to be refractory to antiviral therapy. CONCLUSIONS In summary, we observed that additional use of vitamin D has a positive effect on sustained viral response rates of patients with chronic hepatitis C infection. However, we cannot establish the efficacy because of substantial heterogeneity, a small sample size and a low methodological quality.