Large BP variation tied to subclinical brain structural changes
Elevated blood pressure (BP) variation appears to contribute to a wide range of subclinical brain structural changes, including magnetic resonance imaging (MRI) markers of cerebral small vessel disease, smaller brain tissue volumes and worse white matter microstructural integrity, suggests a recent study.
“These subclinical brain changes could be the underlying mechanism linking BP variation to dementia and stroke,” according to the authors.
A large systolic (S)BP variation (top vs bottom tertiles), measured on average 7 years preceding brain MRI, led to an increased likelihood of having severe white matter hyperintensities (WMH; odds ratio [OR], 1.32, 95 percent confidence interval [CI], 1.21–1.43), lacunes (OR, 1.25, 95 percent CI, 1.04–1.48) and microbleeds (OR, 1.16, 95 percent CI, 1.03–1.31).
This variation likewise correlated with smaller total brain volume and worse white matter microstructural integrity (pall<0.001). In addition, a large SBP variation resulted in the progression of WMH (rate ratio, 1.14, 95 percent CI, 1.02–1.27). These brain imaging markers showed higher burdens with both large rises and falls in SBP. Findings for diastolic (D)BP variation were similar.
A total of 2,348 participants aged ≥55 years from a prospective cohort study were included in the analysis. Their BP was measured at each visit every 3–4 years from 1990 onward. Brain MRI was carried out at all visits from 2005 onward.
Variation was assessed as the absolute difference in BP divided by the mean over two sequential visits for both SBP and DBP. The direction of the variation was also further examined. Furthermore, the investigators assessed the multivariate-adjusted associations of BP variation with subsequent measurements of MRI markers of cerebral small vessel disease, brain tissue volumes, and white matter microstructural integrity. They also investigated the longitudinal changes in these markers.