RESUMO
OBJECTIVE: The observed impacts of Garcinia cambogia (GC) on serum leptin indicate inconsistency. We performed a systematic review and meta-analysis on randomized controlled trials (RCTs) to evaluate the effectiveness of GC on leptin levels. METHODS: A thorough literature search was carried out using different online databases, including Scopus, Web of Science, PubMed, and Google Scholar, until May 25, 2024. Using random effects, weighted mean differences (WMDs) and corresponding 95 % confidence intervals (CIs) were computed. Standard procedures were followed to account for publication bias, study quality, and statistical heterogeneity. RESULTS: In this meta-analysis, a total of eight eligible trials with 330 participants were ultimately included. Quality assessment showed that half of the included trials were considered to have fair quality, while the other half were deemed to have poor quality. Our analysis, with no indication of publication bias, showed a significantly decreased effect of GC on leptin compared with the placebo (WMD: -5.01 ng/ml; 95 % CI: -9.22 to -0.80, p = 0.02). However, significant heterogeneity was detected between studies (I2 =93.5 %, p < 0.001). The Hartung-Knapp adjustment did not affect our results. Subgroup analysis revealed that GC consumption represents the most effects in trials with sample size ≥ 50 (WMD: -3.63 ng/ml; 95 % CI [-5.51, -1.76], p < 0.001), and mean age of participants ≥ 30 years (WMD: -7.43 ng/ml; 95 % CI [-9.31, -5.56], p < 0.001). CONCLUSIONS: The findings of the present study showed that leptin levels might decline following GC administration. REGISTRATION NUMBER: CRD42023486370.
RESUMO
Previous studies have assessed how supplementing with policosanol affects blood sugar levels. The outcomes, nevertheless, were not constant. Multiple electronic databases were searched including ISI Web of Science, Cochrane Library, PubMed, Google Scholar, and Scopus until February 9, 2023. To assess the effects of policosanol on glucose, we employed a random-effects or fixed-effects meta-analysis approach to examine the weighted mean differences (WMDs) and associated 95 % confidence intervals (CI) before and after policosanol and placebo administration. The final analysis comprised a total of 25 trials with 2680 participants. Compared to the control group, policosanol supplementation significantly reduced blood glucose levels (WMD: -2.24 mg/dl; 95 % CI: -4.05, -0.42, P = 0.01). Findings from subgroup analysis revealed a significant reduction of policosanol supplementation on glucose levels in period of less than 24 weeks, and in individuals below 50 years of age. Additionally, the reduction was statistically significant in dosage of 10 mg/day. Our dose-response analysis indicates no evidence of a non-linear relationship between policosanol dose and duration and changes in glucose levels (P-nonlinearity = 0.52, and P-nonlinearity = 0.52, respectively). Policosanol supplementation might improve blood glucose. Further trials with more complex designs are required to confirm the findings.