Background: The present study was conducted to clarify whether azelnidipine might have beneficial effects on autonomic functions, and whether such beneficial effects might affect the vascular functions (i.e., arterial stiffness and endothelial function).
Methods and results: This study with a cross-over design was conducted in 21 hypertensive patients (65 +/- 9 years old) being treated with calcium channel blockers (CCBs) other than azelnidipine or benidipine (i.e., during the study period, the CCB was switched to either azelnidipine 16 mg/day or benidipine 4 mg/day, administered alternately for 8 weeks each). Blood examinations were conducted and the heart rate variability, baro-receptor sensitivity (BRS), brachial-ankle pulse wave velocity (baPWV) and flow-mediated vasodilatation (FMD) in the brachial artery were measured after treatment with each of the two drugs. While the blood pressure levels decreased to a similar degree after both treatments, the BRS (8.8 +/- 5.5 ms/mmHg vs. 6.4 +/- 2.9 ms/mmHg, p < 0.01) and high-frequency power component (HF: 139 +/- 152 ms2/Hz vs. 88 +/- 97 ms2/Hz) were higher after treatment with azelnidipine than after treatment with benidipine (p < 0.05). However, the baPWV, FMD and plasma levels of malonyldialdehyde low-density lipoprotein cholesterol and nitric oxides were similar after treatment with both drugs.
Conclusion: Azelnidipine has greater beneficial effects on the autonomic functions than benidipine although the degree of reduction of blood pressure induced by the two drugs was similar. However, this greater beneficial effect of azelnidipine on the autonomic functions did not produce any distinguishable differences in effects of azelnidipine and benidipine on the arterial stiffness and endothelial functions.