Background: Cardiovascular effects of glucose-lowering agents are of increasing interest. Our aim was to assess the effects of the glucagon-like peptide-1 receptor agonist exenatide on heart rate (HR) and blood pressure (BP) in subjects with type 2 diabetes mellitus (T2DM). Methods: In this double-blind, placebo-controlled trial, subjects with T2DM on metformin and/or a thiazolidinedione were randomized to receive exenatide (5 mu g for 4 weeks followed by 10 mu g) or placebo BID for 12 weeks. Heart rate and BP were assessed with 24-hour ambulatory BP monitoring. The primary measure was change from baseline in mean 24-hour HR. Results: Fifty-four subjects (28 exenatide, 26 placebo) were randomized and comprised the intent-to-treat population. Baseline values (exenatide and placebo) were (mean +/- SE) 74.4 +/- 2.1 and 74.5 +/- 1.9 beats/minute for HR, 126.4 +/- 3.2 and 119.9 +/- 2.8 mm Hg for systolic BP (SBP), and 75.2 +/- 2.1 and 70.5 +/- 2.0 mm Hg for diastolic BP (DBP). At 12 weeks, no significant change from baseline in 24-hour HR was observed with exenatide or placebo (LS mean +/- SE, 2.1 +/- 1.4 versus -0.7 +/- 1.4 beats/minute, respectively; between treatments, p - 0.16). Exenatide therapy was associated with trends toward lower 24-hour, daytime, and nighttime SBP; changes in DBP were similar between groups. No changes in daytime or nighttime rate pressure product were observed. With exenatide, body weight decreased from baseline by -1.8 +/- 0.4 kg (p < 0.0001; treatment difference -1.5 +/- 0.6 kg, p < 0.05). The most frequently reported adverse event with exenatide was mild to moderate nausea. Conclusions: Exenatide demonstrated no clinically meaningful effects on HR over 12 weeks of treatment in subjects with T2DM. The observed trends toward lower SBP with exenatide warrant future investigation.
