Background Impaired glucose tolerance (IGT), an alteration that is part of prediabetes, is a transition state to type 2 diabetes mellitus. Metformin is the first-choice drug for prediabetes treatment. Novel interventions with the ability to modify the evolution of prediabetes to diabetes should be studied. Gymnema sylvestre, a typical plant from India used in complementary and alternative medicine, has been known for years for its hypoglycemic effects. Aims To evaluate the effect of Gymnema sylvestre administration on glycemic control, insulin secretion and insulin sensitivity in patients with IGT. Method A randomized, double-blind, placebo-controlled clinical trial was conducted in 30 patients with IGT. Fifteen patients randomly received Gymnema sylvestre in doses of 300 mg twice daily, the other 15 received placebo in the same way. Before and after the intervention, anthropometric and metabolic measurements were taken, including 2-h postload plasma glucose (2-h PG) by consuming 75-g of a dextrose load, fasting plasma glucose (FPG), glycated hemoglobin A1c (A1C) and a lipid profile. Area under curves of glucose and insulin were calculated, as well as the insulinogenic, Stumvoll and Matsuda indices. Wilcoxon, Mann-Whitney U and Chi-square tests were performed, and p ≤ 0.05 was considered statistically significant. Results There was a significant reduction after administration of Gymnema sylvestre in 2-h PG (9.1 ± 1.2 vs 7.8 ± 1.6 mmol/L, p = 0.003), A1C (5.8 ± 0.3 vs 5.4 ± 0.4 %, p= 0.025), body weight (BWt) (79.6 ±11.9 vs 77.4 ±11.6 kg, p= 0.002 ), body mass index (BMI) (31.1 ± 3.7 vs 30.3 ± 3.6 kg/m2, p= 0.002), and low density lipoprotein cholesterol (LDL-C) (3.5 ± 0.8 vs 2.5 ± 1.3 mmol/L, p= 0.025) levels, with an increment in the Matsuda index (1.76 ± 0.77 vs 2.40 ± 1.16), p = 0.008). In the group of Gymnema sylvestre A1C decreased to normal levels in 46.7% of patients while in the placebo group, no patient decreased to normal levels (p= 0.003). Discussion It is important to note that this is the first study aimed to determine the effect of Gymnema sylvestre in patients with IGT. Gymnema sylvestre administration in patients with IGT significantly decreased 2-h PG, A1C, BWt, BMI and LDL-C, while increasing insulin sensitivity.
No datasets are available for this submission.