Effect of 8 weeks’ supplementation grape seed extract on insulin resistance in iranian adolescents with metabolic syndrome: A randomized controlled trial

Abstract

Background and aimsInsulin resistance in adolescents is a major health concern. The aim of this study was to evaluate the effect of grape seed extract on insulin resistance in adolescents with metabolic syndrome (MetS). MethodsParticipants were divided into grape seed extract (GSE) and placebo groups (n = 24 each) and received 100 mg/day of GSE or placebo and were placed on a weight loss diet for 8 weeks. Anthropometric and biochemical indices, blood pressure, dietary intake, and physical activity were measured before and after the intervention. ResultsForty-two participants completed the trial. After the intervention, the age, sex, baseline values, energy intake and physical activity as a covariate adjusted using ANCOVA for determine differences between groups. The MD (mean difference ±SEM) of HOMA-IR between the GSE group (−1.46 ± 0.45) and the placebo group (−0.48 ± 0.47), (p = 0.020), and the MD of insulin between the GSE group (−7.05 ± 2.11) and the placebo group (−1.71 ± 2.12), (p = 0.024), were significant. Although changes were observed in other variables, they were not statistically significant. ConclusionsGSE improves insulin concentration and insulin resistance in adolescents with MetS and provides a basis for possible application of the GSE in the clinical management of MetS in adolescents. This study registered under Randomized Clinical Trials.gov Identifier no. IRCT2013112611288N7.