Zinc Supplementation and BodyWeight: A Systematic Review and Dose–Response Meta-analysis of Randomized Controlled Trials

The aim of this study was to determine the effect of zinc supplementation onanthropometric measures. In this systematic review and dose–response meta-analysis, wesearched PubMed, Scopus, ISI Web of Science, and the Cochrane Library from databaseinception to August ۲۰۱۸ for relevant randomized controlled trials. Mean differences andSDs for each outcome were pooled using a random-effects model. Furthermore, a dose–response analysis for zinc dosage was performed using a fractional polynomial model.Quality of evidence was evaluated using the Grading of Recommendations Assessment,Development and Evaluation (GRADE) methodology. Twenty-seven trials (n= ۱۴۳۸participants) were included in the meta-analysis. There were no significant changes inanthropometric measures after zinc supplementation in the overall analysis. However,subgroup analyses revealed that zinc supplementation increased body weight in individualsundergoing hemodialysis (HD) [۳ trials, n = ۱۵۴ participants; weighted mean difference(WMD) = ۱.۰۲ kg; ۹۵% CI: ۰.۳۸, ۱.۶۵ kg; P= ۰.۰۰۲; I۲ = ۱۱.۴%] and decreased body weightin subjects who are overweight/obese but otherwise healthy (۵ trials, n= ۲۴۵ participants;WMD=−۰.۵۵ kg; ۹۵% CI: −۱.۰۶, −۰.۰۴ kg; P= ۰.۰۳; I۲ = ۳۱.۵%). Dose– response analysesrevealed a significant nonlinear effect of supplementation dosage on BMI (P=۰.۰۰۱).Our datasuggest that zinc supplementation increases body weight in patients undergoing HD anddecreases body weight in individuals who are overweight/obese but otherwise healthy,although after normalization for study duration, the association observed in subjects who areoverweight/obese disappeared. Although more high-quality studies are needed to reach adefinitive conclusion, our study supports the view that zinc may be associated with bodyweight. Adv Nutr ۲۰۲۰;۱۱:۳۹۸–۴۱۱

کلیدواژه ها:

zinc ، obesity ، body weight ، body mass index ، dose–response ، meta-analysis