Dietary supplements for prediabetes: A protocol for a systematic review and meta-analysis.

BACKGROUND: The number of prediabetic individuals is at a high level worldwide and they have an increased risk of developing diabetes, causing severe physical impairment and heavy financial burden. Recently, using various dietary supplements is increasingly common, and relevant trials of different diseases are increasing correspondingly. The effects of dietary supplements have been confirmed in some studies among prediabetic individuals. However, there remains no comprehensive systematic review to assess the efficacy and safety of dietary supplements intake in prediabetic individuals. METHODS: We plan to search and retrieve applicable randomized controlled trials of dietary supplements for prediabetic individuals in the following databases before June 2020: PubMed, Web of Science, EMBASE, the Cochrane Library, the Cochrane Central Register of Controlled Trials(CENTRAL), Allied and Complementary Medicine Database(AMED), Chinese Biomedical Literature database, Wan Fang database, Chinese Scientific Journal database (VIP), Chinese National Knowledge Infrastructure database(CNKI), and the ClinicalTrials.gov website. Two reviewers will separately perform study selection, data extraction, methodological quality assessment and quality of evidence assessment. Data analysis and publication bias will be conducted by Review Manager 5.3. RESULTS AND CONCLUSIONS: This evidence-based medicine systematic review will prove the efficacy and safety of multifarious dietary supplements for prediabetes. ETHICS AND DISSEMINATION: As this systematic review is based merely on already published literature, no approval of the ethics committee is required. We will disseminate this systematic review to a peer-reviewed journal. PROTOCOL REGISTRATION NUMBER: INPLASY202040057.