Hermes Florez, Richard Scranton, Wildon R. Farwell, Ralph A. DeFronzo, Michael Ezrokhi, J. Michael Gaziano and Anthony H. Cincotta
Aims: To evaluate the glycemic control efficacy and cardio-metabolic safety of bromocriptine- quick release (Bromocriptine-QR) among subjects with type 2 diabetes who were taking a thiazolidinedione (TZD) at baseline.
Methods: A subgroup from the Cycloset Safety trial who were taking a TZD at baseline with or without another oral anti-diabetes medication were randomized to receive additional once daily (morning) bromocriptine-QR (1.6 - 4.8 mg/day) or placebo for up to 52 weeks. Glycemic efficacy analyses were based on intent to treat modified (ITTm) and evaluable per protocol (EPP) population using general linear model after adjusting for baseline covariates and stratified by A1C level of <7.5 of ≥7.5. The odds ratio of participants achieving A1C ≤7% were calculated. Similar analyses for safety were performed on weight and hypoglycemia.
Results: In this trial 495 subjects were taking a TZD at baseline and 122 also had a baseline A1C of ≥7.5. For subjects with an A1C of ≥7.5, bromocriptine-QR treatment led to significant reduction in A1C (ITTm -0.81%, p=0.001and EPP -0.91%, p=0.002), fasting plasma glucose (ITTm -21.5 mg/dl, p=0.03 and EPP -20.5 mg/dl, p=0.05), and higher frequency achieving an A1C≤7% (32.1% vs. 15.9%, p=0.05) when compared with placebo. For subjects with a baseline A1C of <7.5, subjects randomized to bromocriptine-QR had a greater odds of having an A1C level of ≤7.0 (OR 2.74, 95% CI 1.45, 5.15; p =0.002). Treatment with bromocriptine-QR had no adverse impact on weight or risk of hypoglycemia.
Conclusion: Daily morning bromocriptine-QR added to ongoing TZD treatment for uncontrolled type 2 diabetes improved glycemic control and was well tolerated.