Effect of Aloe vera on glycaemic control in prediabetes and type 2 diabetes: a systematic review and meta-analysis.

Aloe vera (Aloe vera (L.) Burm.f., Xanthorrhoeaceae family) has long been used in folk or traditional medicine for diabetes. Several studies have been conducted on the effect of Aloe vera on glycaemic control, but the results appear inconsistent. We undertook a systematic review and meta-analysis to assess the effect of Aloe vera on glycaemic control in prediabetes and type 2 diabetes. A comprehensive literature search was conducted through MEDLINE, CENTRAL, CINAHL, Scopus, http://clinicaltrials.gov, Web of Science, Proquest, LILACS, HerbMed, NAPRALERT and CNKI to the end of January 2016 without language restriction. Historical search of relevant articles and personal contact with experts in the area were also undertaken. Studies were included if they were (1) randomized controlled trials of Aloe vera aimed at assessing glycaemic control in prediabetes or type 2 diabetes and (2) reporting fasting plasma glucose (FPG) or haemoglobin A1c (HbA1c ). Treatment effect was estimated with mean difference in the final value of FPG and HbA1c between the treatment and the control groups. Eight trials involving 470 patients (235 each for prediabetes and type 2 diabetes) were included. In prediabetes, Aloe vera significantly improved FPG (mean difference -0·22 mmol/L, 95% CI -0·32 mmol/L to -0·12 mmol/L, P < 0·0001), with no effect on HbA1c (mean difference -2 mmol/mol, 95% CI -5 mmol/mol to 1 mmol/mol). Aloe vera may improve glycaemic control in type 2 diabetes, with a marginal improvement in FPG (mean differences -1·17 mmol/L, 95% CI -2·35 mmol/L to 0·00 mmol/L, P = 0·05) and a significant improvement in HbA1c (mean difference -11 mmol/mol, 95% CI -19 mmol/mol to -2 mmol/mol, P = 0·01). The current evidence suggests some potential benefit of Aloe vera in improving glycaemic control in prediabetes and type 2 diabetes. However, given the limitations of the available evidence and the high heterogeneity in study results, high-quality, well-powered randomized controlled trials using standardized preparations are needed to quantify any beneficial effects of Aloe vera on glycaemic control.

Suksomboon N ，Poolsup N ，Punthanitisarn S 《-》

Efficacy of Aloe Vera Supplementation on Prediabetes and Early Non-Treated Diabetic Patients: A Systematic Review and Meta-Analysis of Randomized Controlled Trials.

Zhang Y ，Liu W ，Liu D ，Zhao T ，Tian H ... -  《Nutrients》

Effect of dragon fruit on glycemic control in prediabetes and type 2 diabetes: A systematic review and meta-analysis.

Poolsup N ，Suksomboon N ，Paw NJ 《-》

Effect of vitamin D supplementation on insulin resistance and glycaemic control in prediabetes: a systematic review and meta-analysis.

To evaluate the effect of vitamin D on insulin resistance and glycaemic control in prediabetes. A literature search was conducted of MEDLINE, the Cochrane Library, Cumulative Index to Nursing and Allied Health Literature (CINAHL), Scopus, Web of Science and www.clinicaltrials.gov, together with a historical search through the reference lists of relevant articles until end of June 2014. Studies were included if they were randomized controlled trials of vitamin D or vitamin D analogues in prediabetes and if they reported homeostatic model assessment of insulin resistance or 2-h plasma glucose after oral glucose tolerance test. Treatment effect was estimated according to mean difference in the changes from baseline of homeostatic model assessment of insulin resistance, 2-h oral glucose tolerance test plasma glucose, fasting plasma glucose and HbA1c between vitamin D and control groups. Meta-analysis of eligible studies was performed. A total of 10 randomized controlled trials were included. Vitamin D did not significantly improve homeostatic model assessment of insulin resistance and 2-h oral glucose tolerance test plasma glucose: the mean differences were -0.06 (95% CI -0.36 to 0.24) and -0.23 mmol/l (95% CI -0.65 to 0.19), respectively. Subgroup analysis suggested that vitamin D improved homeostatic model assessment of insulin resistance in a subgroup with baseline 25-hydroxyvitamin D ≥ 50 nmol/l [mean difference -0.59 (95% CI -1.14 to -0.04); P = 0.03] and improved 2-h oral glucose tolerance test plasma glucose in the subgroup with baseline 25-hydroxyvitamin D < 50 nmol/l [mean difference -0.68 mmol/l (95% CI -1.35 to -0.01); P = 0.05]. Vitamin D significantly reduced fasting plasma glucose and HbA1c levels. The mean differences were -0.10 mmol/l (95% CI -0.18 to -0.03), P = 0.006 and -1 mmol/mol (95% CI -2 to 0), P = 0.008, respectively. No beneficial effect of vitamin D in improving insulin resistance was identified.

Poolsup N ，Suksomboon N ，Plordplong N 《-》

Chinese herbal medicine for impaired glucose tolerance: a randomized placebo controlled trial.

Grant SJ ，Chang DH ，Liu J ，Wong V ，Kiat H ，Bensoussan A ... -  《BMC Complementary and Alternative Medicine》