Liraglutide increases 24-h heart rate by reducing the cardiac parasympathetic activity of patients with type 2 diabetes: power spectral analysis of heart rate variability on 24-h Holter ECG recordings

The effects of liraglutide, a glucagon-like peptide 1 receptor agonist, on heart rate over a 24-h period (24-h heart rate) and on parasympathetic modulation of heart rate among patients with type 2 diabetes were investigated by 24-h power spectral analysis (PSA) of heart rate variability. Seven consecutive male patients with type 2 diabetes received once-daily subcutaneous injection of liraglutide (0.9 mg). We performed 24-h Holter electrocardiographic recording at baseline and after treatment for 24 weeks. PSA revealed that R–R variability data were distributed in two bands: low-frequency (LF) and high-frequency (HF) power. Compared with baseline, heart rate after treatment for 24 weeks was higher at every hour, with a significant difference for 15 of the 24 h time points. LF power was significantly reduced at two measurement points, and HF power was significantly reduced at four points. In addition, heart rate was significantly increased at all points at which LF or HF power was significantly reduced after treatment with liraglutide for 24 weeks. In conclusion, liraglutide increases 24-h heart rate after treatment for 24 weeks, possibly by inhibiting cardiac parasympathetic (vagal) activity.