The effect of green tea on blood pressure in patients with type 2 diabetes mellitus: A systematic review and meta-analysis

Background and objectives: Previous trials conducted on patients with type 2 diabetes mellitus (T2DM) showed controversial results regarding the efficacy of green tea (GT) in improving blood pressure (BP). We conducted a review and meta-analysis of randomized controlled trials (RCTs) to summarize the effect of GT supplementation on BP among patients with T2DM. Methods and study design: Online databases, including PubMed/Medline, Scopus, and ISI web of science, were searched up to March 2021 to retrieve RCTs that examined the effect of GT on BP in patients with T2DM. Meta-analyses were carried out using a random effects model. The I2 index was used to evaluate the heterogeneity. Results: Among the initial 854 studies identified from electronic databases search, ten trials, which included 681 participants, were eligible. Pooled effect size from 10 studies indicated that supplementary intake of GT had no significant effect on systolic blood pressure (SBP) (Mean Difference (MD): 0.00 mmHg, 95 % CI: (-0.01, 0.01), p = 0.997), with no significant heterogeneity between the studies (I2 = 8.8 %, p = 0.356) and diastolic blood pressure (DBP) (MD:-0.90 mmHg, 95 % CI: (-2.21, 0.41), p = 0.178), with significant heterogeneity among the studies (I2 = 55.6 %, p = 0.006). Subgroup analysis revealed that GT supplementation lowers DBP when intervention is conducted on patients with elevated DBP. Conclusion: Our meta-analysis revealed that although GT supplementation has no significant effect on general BP in patients with T2DM, it may significantly improve DBP in patients with T2DM who have high DBP

The effects of purslane consumption on glycemic control and oxidative stress: A systematic review and dose–response meta‐analysis

Abstract Purslane (Portulaca oleracea L.) is a herbal remedy with wide range of pharmaceutic properties. Although the beneficial effect of purslane on the treatment of Type 2 Diabetes Mellitus (T2DM) has been shown, there is an inconsistency among the results of previous studies. Therefore, this study is aimed at conducting a systematic review and meta‐analysis on the effect of purslane on glycemic profile and oxidative stress markers. A systematic search was performed in the Scopus, Web of science, PubMed and the Cochrane Library to find articles related to the effect of the purslane on Malondialdehyde (MDA) and Total Antioxidant Capacity (TAC), Fasting Blood Sugar (FBS), Hemoglobin A1c (HbA1c), insulin resistance, Homeostatic Model Assessment for Insulin Resistance (HOMA‐IR) up to September 2022. Among the 611 initial studies that were identified from searching electronic databases, 16 Randomized Clinical Trials (RCTs) involving 1122 participants (557 cases and 565 controls) were included for data analysis. The results of random‐effects modeling demonstrated that purslane consumption significantly reduced FBS (p < .001), MDA (p < .001) and increased TAC (p < .001). However, purslane consumption did not affect HbA1c (p < .109), fasting insulin (p = .298) and HOMA‐IR (p = .382). Meta‐analyses were performed using both the random‐ and fixed‐effects model where appropriate, and I2 index was used to evaluate the heterogeneity. This meta‐analysis study suggests that purslane has beneficial effects on oxidative stress markers and glycemic parameter. Therefore, it may be a promising adjuvant therapy in T2DM because of its benefits and negligible adverse effects