The Effect of α-lipoic Acid on C-Reactive Protein Level: A Meta-analysis of Randomized, Double-Blind, and Placebo-Controlled Studies

Ljiljana Đukić; Lazar Trajković; Tamara Knežević; Jelena Dimitrijević; Danijela Krstić; Marko Stojanović

doi:10.1177/15593258221126827

The Effect of α-lipoic Acid on C-Reactive Protein Level: A Meta-analysis of Randomized, Double-Blind, and Placebo-Controlled Studies

Dose Response. 2022 Oct 13;20(4):15593258221126827. doi: 10.1177/15593258221126827. eCollection 2022 Oct-Dec.

Authors

Ljiljana Đukić¹, Lazar Trajković², Tamara Knežević³, Jelena Dimitrijević⁴, Danijela Krstić⁵, Marko Stojanović⁶

Affiliations

¹ School of Dental Medicine, Department of Pharmacology in Dentistry, University of Belgrade, Belgrade, Serbia.
² Faculty of Medicine, University of Belgrade, Belgrade, Serbia.
³ Department of Gastroenterology, University Hospital Zvezdara, Belgrade, Serbia.
⁴ Institute for Oncology and Radiology of Serbia, Belgrade, Serbia.
⁵ Faculty of Medicine, Institute of Medical Chemistry, University of Belgrade, Belgrade, Serbia.
⁶ Faculty of Medicine, Department of Pharmacology, University of Belgrade, Clinical Pharmacology and Toxicology, Belgrade, Serbia.

Abstract

The C-reactive protein is generally considered a marker of inflammation, and it is widely used in clinical practice as a minimally invasive index of any ongoing inflammatory response. Alpha-lipoic acid (ALA) supplementation can be beneficial for human health, especially in the sense of its anti-inflammatory action. The aim of this meta-analysis was to, based on the currently available highest level of evidence (prospective, randomized, double-blind, and placebo-controlled data), investigate the effect of ALA supplementation on CRP levels. Prospective, randomized, double-blind, and placebo-controlled clinical trials were extracted after a systematic search of PubMed, the Cochrane Library, the Web of Science, EMBASE, and the Scopus databases. A random effect model was used in this meta-analysis to investigate the influence of ALA on the blood CRP level. The subgroup analysis and meta-regression were used to identify the source of heterogeneity. This meta-analysis provided evidence of the positive effect of ALA on the reduction of the blood CRP level. The subgroup analysis and meta-regression results indicated that ALA can reduce the CRP level when administrated at a 600 mg dose, and not in higher or lower doses. Also, a shorter duration of study positively correlates with the reduction of CRP after ALA supplementation.

Keywords: C-reactive protein; alpha-lipoic acid; dose-dependent effect; duration-dependent effect; meta-analysis.