Effect of a calcium-channel blocker and β-blocker combination on reading-to-reading blood pressure variability: a randomized crossover trial

OBJECTIVE: The objective of this study was to investigate the efficacy of the nitrendipine/atenolol combination in comparison with standard-dose nitrendipine or atenolol monotherapy in reducing blood pressure (BP) and blood pressure variability (BPV) as assessed by ambulatory BP monitoring. METHODS: In a randomized, crossover trial, 32 patients (30-65 years) with grade 1 hypertension and elevated daytime reading-to-reading BPV were randomly assigned to receive either the nitrendipine/atenolol combination (10/20 mg) or standard-dose nitrendipine (10 mg) or atenolol (25 mg) monotherapy for 6 weeks, followed by a crossover to another treatment for 6 weeks. RESULTS: The final analysis included 31 patients (mean [±SD] age, 49.2 ± 9.6 years) and 12 men. The nitrendipine/atenolol combination significantly reduced from baseline clinic and ambulatory BP and pulse rate ( P ≤ 0.002), and 24 h and daytime systolic and diastolic BPV as assessed by SD and average real variability ( P ≤ 0.042), but not the coefficient of variation nor nighttime BPV indices ( P ≥ 0.06). Significant differences between the nitrendipine/atenolol combination and nitrendipine or atenolol monotherapy at the end of treatment were observed in clinic BP and pulse rate ( P ≤ 0.042), but not in 24 h, daytime and nighttime blood pressure and pulse rate, except for daytime DBP and 24 h and daytime pulse rate ( P ≤ 0.049). There were no significant differences in BPV between the combination and monotherpy groups at the end of treatment ( P ≥ 0.25). CONCLUSION: The nitrendipine/atenolol combination reduced daytime reading-to-reading BPV, but did not show superiority to nitrendipine or atenolol monotherapy.