Background: Previous studies suggested blood pressure variability (BPV) might help reveal interactions between blood pressure fluctuation and white matter lesions, and the impact of elevated BPV on white matter hyperintensity (WMH) or cerebral arterial dilation is unclear.
Methods: This retrospective observational study involved 2634 stroke-free individuals (68.6±11.1 years, 50.3% female), who underwent magnetic resonance imaging and magnetic resonance angiography scans, from a single center in Shanghai, China. Measurements for variability of blood pressure were made based on 7 days blood pressure recordings. WMHs were quantified from T2-FLAIR images and further classified as periventricular WMH or deep WMH. M1 segment of middle cerebral artery dilation was assessed from magnetic resonance angiography images. General linear model was used to examine the associations.
Results: Both increased systolic and diastolic BPV were associated with increased WMH volume (systolic: β=0.02 [95% CI, 0.004-0.03], P=0.01; diastolic: β=0.05 [95% CI, 0.03-0.08], P<0.001). Only periventricular WMH was associated with BPV (systolic: β=0.02 [95% CI, 0.005-0.04], P=0.01; diastolic: β=0.06 [95% CI, 0.04-0.09], P<0.001). MCA dilation was found in 125 individuals (4.75%). Systolic BPV was associated with MCA dilation only in the hypertensive individuals (β=0.11 [95% CI, 0.06-0.17], P<0.001). Increased WMH volume was found associated with dilated MCA (β=0.17 [95% CI, 0.11-0.23], P<0.001).
Conclusions: Increased BPV might be one of the pathophysiological phenomena involving in the small vessel disease independent of hypertension. Increased BPV might independently contribute to intracranial arterial dilation. Management of BPV might be a target to preserve cerebrovascular wellness.
Keywords: angiography; blood pressure; cerebral small vessel disease; dementia; hypertension.