Meta-analysis of the anti-oxidative and anti-inflammatory effects of hypoglycaemic plant-derived medicines.

BACKGROUND: The pivotal role of oxidative stress and inflammation in the pathophysiology of type 2 diabetes mellitus (T2DM) has been firmly established. However, the evidence concerning hypoglycaemic medicinal plants' antioxidant and anti-inflammatory effects remains inconclusive due to inconsistencies in prior studies. To address this gap, our study aims to perform a comprehensive systematic review and meta-analysis of randomized controlled trials (RCTs) to consolidate previous research findings in this field. METHODS: We conducted a comprehensive search in the PubMed, Web of Science, Embase, Cochrane Library, and Scopus databases to identify relevant English randomized controlled trials (RCTs). Our study adhered to the Preferred Reporting Items for Systematic Review and Meta-analysis (PRISMA) guidelines. All eligible studies that evaluated concurrently the antioxidative and anti-inflammatory effects of hypoglycaemic plant-derived supplements on type 2 diabetes mellitus (T2DM) were included in the meta-analysis. The meta-analysis itself was carried out using both fixed and random effects models to synthesize the findings from the selected studies. RESULTS: Our study included 47 trials with a total of 2636 participants, both male and female, aged between 20 and 79 years, diagnosed with prediabetes, type 2 diabetes mellitus (T2DM), or metabolic syndrome. The meta-analysis revealed that plant-derived treatments, compared to placebos or other medicines, significantly improved oxidative stress (SMD = - 0.36, 95% CI - 0.64 to - 0.09), inflammation (SMD = - 0.47, 95% CI - 0.63 to - 0.31), total antioxidant capacity (SMD = 0.46, 95% CI 0.16-0.75), and antioxidant enzyme activity (SMD = 1.80, 95% CI 1.26-2.33). The meta-regression analysis showed that treatment duration exceeding 8 weeks significantly impacted the heterogeneity of the oxidative stress data. CONCLUSIONS: Several hypoglycaemic plant-based treatments appear to positively affect T2DM patients by concurrently lowering oxidative stress and inflammatory indicators and boosting antioxidant enzyme activity. CLINICAL TRAIL REGISTRY: PROSPERO ID: CRD42021226147.

Withdrawal reasons of randomized controlled trials on type 2 diabetes: a systematic review.

PURPOSE: Type 2 diabetes mellitus (T2DM) is the subject of numerous randomized controlled trials (RCTs). The validity of RCTs may be threatened by attrition bias due to the discontinuation of the study. The aim of this systematic review is to evaluate the reasons of patient's withdrawal from these RCTs. METHODS: A systematic literature search on PubMed, Cochrane Library, Web of Science, and Scopus databases was conducted in accordance with the Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) flow diagram. The aim was to obtain all relevant blinded RCTs published before January 2017 in which the effectiveness of synthetic drugs, vitamins/minerals were compared to that of placebo or active control in T2DM. The quality of RCTs was assessed using the Jadad score. The frequency of withdrawal reasons was presented based on treatments with placebo/active control, national/international level of the studies, and publication year. Meta-analysis was not performed due to the heterogeneity. RESULTS: Overall, 1368 articles comprising of 640,780 subjects were included. In the majority of the RCTs (75.0%), the intervention and the placebo arms were compared. Most of the included studies (96%) were classified in the high-quality category (Jadad score≥3). The highest proportion of reported withdrawal cases was found in international studies, national RCTs conducted in Japan, and RCTs published in 2011. The withdrawal reasons were reported for 91,669 (63.75%) of the total 143,794 participants who had withdrawn from these studies. The main reported reasons were "adverse effects" (24.04%), "withdraw consent" (16.10%), and "missing data" (11.08%). Variations in the reported withdrawal reasons were based on the country or published year. RCTs with triple blinded design as well as those in which anti-hyperlipidemia and anti-obesity medications were applied, showed significantly higher probability of reported the withdrawal. CONCLUSION: High proportion of reported discontinuation in blinded RCTs on patients with T2DM was related to drug adverse effects. Overall, the total number and reason of drop out were unsatisfactory.