Background: Researching the topic of glycemic variability (GV) has been very interesting due to the possible relationship that exists between this phenomenon and the development of micro- and macrovascular complications. The aim of this investigation was to evaluate the effect that metformin had on the GV in pre-diabetic patients.
Materials and methods: A randomized, double-blind, placebo-controlled clinical trial was carried out in 20 subjects, both male and female participants were chosen. These subjects where then divided into 2 groups; 10 subjects received metformin (500 mg) while the remaining 10 subjects received a placebo, twice daily, before breakfast and dinner over the course of 90 days. Metabolic screening, which included glycated hemoglobin A1c, fasting plasma glucose (FPG), 2 h oral glucose tolerance test with 75 g of dextrose and GV [area under the curve of glucose, mean amplitude of glycemic excursion (MAGE)], were measured for all patients at baseline and at the end of the study. Wilcoxon signed-rank, and Mann-Whitney test were performed as part of the statistical analysis.
Results: Baseline characteristics of both groups were similar. There was a significant decrease of FPG levels in the metformin group as compared to placebo (6.3 ± 0.7 vs. 5.6 ± 1.0 mmol/L, p=0.047). There were no significant differences in the GV parameters in either of the two study groups.
Conclusion: Pre-diabetic subjects treated with metformin for 3 months showed a significant decrease in FPG when compared to placebo.