Visit-to-visit blood pressure variability and the risk of cardiovascular disease: a prospective cohort analysis

Large blood pressure (BP) variability contributed to subclinical brain disease thus may be implicated in the development of cardiovascular disease (CVD). This study included 64,810 CVD-free participants who attended the first two examinations from the Kailuan study to investigate the association of BP variation, considering its magnitude, direction, and time interval prior to CVD diagnosis, with the risk of CVD in Chinese population. Magnitude and directional BP variability was calculated as absolute BP difference or BP difference value divided by mean BP over 2 sequential visits, respectively. During a median follow-up of 10.91 years, a total of 4129 cases of CVD. A large SBP variability (the highest vs the lowest tertile) was associated with a higher risk of CVD (adjusted HR, 1.31; 95% CI, 1.22-1.41). The associations were stronger with longer time intervals, the hazard ratio (HR) with 95% confidence interval (CI) for CVD was 1.30 (95% CI, 1.20-1.39) at 1 years, 1.32 (1.18-1.40) at 3 years, and 1.34 (1.20-1.45) at 5 years. For directional SBP variability, rise in SBP was associated with an increased risk of CVD (HR, 6.17; 95% CI, 5.65-6.75), while fall in SBP was associated with a decreased risk of CVD (HR, 0.52; 95% CI, 0.46-0.59). Subgroup analysis showed the significant associations were only observed in men (P_int = 0.0010). Similar patterns were observed for DBP variability and CVD subtypes. The results indicated that a large SBP variation in rise direction was associated with an increased risk of incident CVD, especially in men.