Background: It is suggested that bromocriptine could be effective in treatment of prediabetic patients and, consequently, in preventing type 2 diabetes (T2DM). In this study, we investigated the effectiveness of bromocriptine on glycemic and metabolic control of prediabetic patients.

Materials and methods: In this double-blind, placebo controlled trial study, prediabetic patients diagnosed during Isfahan Diabetes Prevention Project (IDPP) were enrolled. They randomized in two bromocriptine (2.5 mg) and placebo-treated groups, for 12 weeks. After physical examination, fasting plasma glucose (FPG), HbA1c, Insulin, cholesterol, HDL-c, and triglyceride were measured and glucose tolerance test (OGTT) was performed. HOMA-IR and LDL-c were calculated. The mean of the data were compared in the bromocriptine and placebo treated groups, before and after intervention by intention to treat analysis using mixed effect model. P values < 0.05 were considered, statistically, significant. Results: In this study, 53 prediabetic patients (27 in the bromocriptine group and 26 in the placebo group) were treated. There were no differences between data of two groups at baseline (P > 0.05). The mean body mass index, systolic blood pressure, fasting plasma glucose and glucose of 30 min, 60 min, 120 min of post OGTT, HbA1c, insulin, HOMA-IR, lipid profile did not change, significantly, in both bromocriptine and placebo-treated groups after 12 weeks (P > 0.05). However, diastolic blood pressure (P = 0.02) and the area under the curve of glucose (P = 0.045) were decreased in the bromocriptine-treated group.

Conclusion: Bromocriptine did not have significant effect on glycemic control of prediabetic patients. Further studies, with bigger sample size are recommended.