Effect of alpha lipoic acid on Iron metabolism parameters: A systematic review and meta- analysis of randomized controlled clinical trials

Background: Alpha-lipoic acid (ALA) exhibits antioxidant and iron chelator properties and may have regulating effects on factors related to Iron metabolism. However, findings from clinical trials are equivocal. This systematic review and meta-analysis aimed to evaluate the effect of ALA supplementation on iron metabolism parameters including serum iron, total iron binding capacity, hemoglobin and ferritin. Methodology We searched online databases, including PubMed, Scopus, and Web of Science, up to 29 May 2022, to obtain relevant publications. Results A total of 1901 records were identified in the systematic search; from these, 10 were included in the systematic review and meta-analysis. The pooled analysis of the studies showed no effects of ALA on ferritin (WMD= -11.01 ng/ml; 95% CI: -40.07, 18.05 ng/ml; I 2  = 0.0%, P = 0.670), serum Iron (WMD=-0.47 µ/dL; 95% CI: -24.48, 23.54 µ/dl; I 2  = 94.7%, P < 0.001), hemoglobin (WMD = 0.49 g/dl; 95% CI: -0.54, 1.52 g/dl; I 2  = 95.7%, P < 0.001), and TIBC (WMD = 3.95 µ/dL; 95% CI: -21.3, 29.2 µ/dl; I 2  = 53.1%, P = 0.094). In subgroups analysis ALA significantly increased hemoglobin in patients with hematological disorders (WMD = 1.23 g/dl; 95% CI: 1.00, 1.45 g/dl; I 2  = 96.6%, P  8 weeks (WMD = 1.03 g/dl; 95% CI: 0.82, 1.25 g/dl; I 2  = 96.5%, P = 0.02). Conclusion ALA supplementation yielded no significant effect on Iron related parameters. Subgroup analysis revealed a significant increasing effect of ALA on hemoglobin in patients with hematological disorders and durations > 8 weeks. More consistent clinical trials, with larger sample size, and consideration more strength inclusion criteria, are required.