Leukoaraiosis and ambulatory blood pressure load in a healthy elderly cohort study: the PROOF study.

Background: Old age and hypertension are consistently reported to be the main risk factors of leukoaraiosis. The association between white matter lesions (WMLs) and other cardiovascular risk factors (CVRF) remains controversial. We evaluated the association between CVRF and WMLs in a cohort study and determined the blood pressure variables that could predict WML severity.

Methods: 830 subjects (65+/-1 years of age, 60% women) from the PROOF study, with a reliable ABPM and brain MRI, were included. The exclusion criteria included prior myocardial infarction, stroke, heart failure, atrial fibrillation, type 1 diabetes mellitus, and pacing. White matter changes on MRI were defined as hyperintensities >5mm on FLAIR images. We used the total degree of WML (range: 0-30) by adding the region-specific scores of both hemispheres.

Results: Linear regression analyses demonstrated a significant relationship between total leukoaraiosis score and 24h systolic blood pressure (SBP), 24h diastolic BP, daytime SBP and DBP and nighttime SBP. No significant relationship was found between leukoaraiosis score and clinical SBP, clinical DBP, or nocturnal DIP. There was also no significant relationship between leukoaraiosis and other recognized cardiovascular risk factors. Based on a ROC curve analysis, we identified the optimal threshold separating high-risk WML patients for a mean 24h SBP above 123 mmHg (p<0.05).

Conclusions: Even moderate increases in 24h SBP promote arteriolar fragility of the cerebral white matter in a population aged 65. The prognostic implications of such abnormalities in asymptomatic and moderate cardiovascular risk populations remain to be evaluated.