Background: The visit-to-visit variability in blood pressure (BP) has been shown to be a strong predictor of cardiovascular events. It is not known whether anti-hypertensive therapy using a single-pill fixed-dose combination of angiotensin II receptor blocker (ARB)/calcium channel blocker (CCB) or ARB/diuretic (DI) in hypertensive patients affects the visit-to-visit variability and seasonal variation of BP.
Methods: We enrolled 47 hypertensive patients who had received a single-pill fixed-dose combination of either ARB/CCB (n = 30) or ARB/DI (n = 17) for 15 months. Beginning 3 months after the start of ARB/CCB or ARB/DI treatment, we determined the visit-to-visit variability in BP expressed as the standard deviation (SD) of average BP and the seasonal variation in BP expressed as the SD of average BP in each season (spring, summer, fall and winter were defined as lasting from March to May, June to August, September to November and December to February, respectively) for a year.
Results: There were no significant differences in baseline patient characteristics except for the prevalence of coronary artery disease and the percentage of CCB excluding amlodipine in the ARB/CCB group between the ARB/CCB and ARB/DI groups. There were no significant differences in the 1-year time course of systolic and diastolic BP (SBP and DBP) between the groups, although there were significant differences in SBP in August and November and DBP in December. Interestingly, the visit-to-visit variability and seasonal variation of BP in the ARB/CCB group were similar to those in the ARB/DI group.
Conclusion: Single-pill fixed-dose combinations of ARB/CCB and ARB/DI had similar effects on visit-to-visit variability and seasonal variation in BP in hypertensive patients.
Keywords: Blood pressure; Seasonal variation; Visit-to-visit variability.