1.
Effects of quercetin supplementation on glycemic control among patients with metabolic syndrome and related disorders: A systematic review and meta-analysis of randomized controlled trials.
Ostadmohammadi, V, Milajerdi, A, Ayati, E, Kolahdooz, F, Asemi, Z
Phytotherapy research : PTR. 2019;(5):1330-1340
Abstract
This systematic review and meta-analysis of randomized controlled trials was performed to determine the effect of quercetin supplementation on glycemic control among patients with metabolic syndrome and related disorders. Databases including PubMed, MEDLINE, EMBASE, Web of Science, and Cochrane Central Register of Controlled Trials were searched until August 30, 2018. Nine studies with 10 effect sizes out of 357 selected reports were identified eligible to be included in current meta-analysis. The pooled findings indicated that quercetin supplementation did not affect fasting plasma glucose (FPG), homeostasis model of assessment-estimated insulin resistance, and hemoglobin A1c levels. In subgroup analysis, quercetin supplementation significantly reduced FPG in studies with a duration of ≥8 weeks (weighted mean difference [WMD]: -0.94; 95% confidence interval [CI; -1.81, -0.07]) and used quercetin in dosages of ≥500 mg/day (WMD: -1.08; 95% CI [-2.08, -0.07]). In addition, subgroup analysis revealed a significant reduction in insulin concentrations following supplementation with quercetin in studies that enrolled individuals aged <45 years (WMD: -1.36; 95% CI [-1.76, -0.97]) and that used quercetin in dosages of ≥500 mg/day (WMD: -1.57; 95% CI [-1.98, -1.16]). In summary, subgroup analysis based on duration of ≥8 weeks and used quercetin in dosages of ≥500 mg/day significantly reduced FPG levels.
2.
Metabolic benefits of curcumin supplementation in patients with metabolic syndrome: A systematic review and meta-analysis of randomized controlled trials.
Azhdari, M, Karandish, M, Mansoori, A
Phytotherapy research : PTR. 2019;(5):1289-1301
Abstract
The finding of studies on the effect of curcumin extract on metabolic factor in patients with metabolic syndrome has had arguable results. This systematic review with meta-analysis of randomized controlled trials (RCT) aimed to analyze the effect of curcumin/turmeric on metabolic factors in patients with metabolic syndrome. The PICO strategy was used to establish the guiding question of this review. Several databases for RCT were searched until September 2018. Of the 144 articles initially identified, seven trials met the eligibility criteria. A random-effects model with a mean weight difference (WMD) and a 95% confidence interval was performed for quantitative data synthesis. Pooled estimates of WMD were calculated between intervention and control groups using random-effects model in the presence of high level of heterogeneity between the studies. The results showed significant improvement of fasting blood glucose (p = 0.01), triglycerides (p < 0.001), high-density lipoprotein cholesterol (p = 0.003), and diastolic blood pressure (p = 0.007) levels. Curcumin was not associated with a significant change in waist circumference measurement (p = 0.6) and systolic blood pressure level (p = 0.269). Curcumin supplementation improves some components of metabolic syndrome.
3.
The Effects of Vitamin D Supplementation on Markers Related to Endothelial Function Among Patients with Metabolic Syndrome and Related Disorders: A Systematic Review and Meta-Analysis of Clinical Trials.
Tabrizi, R, Vakili, S, Lankarani, KB, Akbari, M, Jamilian, M, Mahdizadeh, Z, Mirhosseini, N, Asemi, Z
Hormone and metabolic research = Hormon- und Stoffwechselforschung = Hormones et metabolisme. 2018;(8):587-596
Abstract
This systematic review and meta-analysis of randomized controlled trials (RCTs) were conducted to summarize the effect of vitamin D supplementation on endothelial function among people with metabolic syndrome and related disorders. Cochrane library, Embase, PubMed, and Web of Science database were searched to identify related RCTs published up 20th May 2018. To check heterogeneity a Q-test and I2 statistics were used. Data were pooled by using the random-effect model and standardized mean difference (SMD) was considered as summary effect size. Twenty-two trials of 931 potential citations were found to be eligible for current meta-analysis. The pooled findings by using random effects model indicated that vitamin D supplementation to individuals with MetS and related disorders significantly increased flow-mediated dilatation (FMD) (SMD=1.10; 95% CI, 0.38, 1.81, p=0.003). However, it did not affect pulse-wave velocity (PWV) (SMD=0.04; 95% CI, -0.25, 0.33, p=0.80) and augmentation index (AI) (SMD=0.07; 95% CI, -0.25, 0.40; p=0.65). Overall, this meta-analysis demonstrated that vitamin D supplementation to patients with metabolic syndrome and related disorders resulted in an improvement in FMD, but did not influence PWV and AI.