Extent of Cerebral White Matter Lesions Is Related to Changes of Circadian Blood Pressure Rhythmicity

OBJECTIVE: To evaluate the relationship between circadian blood pressure patterns and the extent of cerebral white matter lesions (WML). DESIGN: Case-control study. PARTICIPANTS: A total of 227 healthy subjects older than 55 years were investigated. Extent and occurrence of WML were evaluated using a computer-supported image analysis system. Circadian blood pressure variation was defined as the average percentage change of nighttime blood pressure compared with the daily blood pressure values. RESULTS: Subjects with WML were significantly older and showed more often a history of hypertension, elevated average systolic daily blood pressure, a reduced systolic circadian blood pressure variation, and an increased incidence of pathological nighttime blood pressure increases. A significant correlation was found between systolic circadian blood pressure variation and the extent of WML. A multiple regression analysis revealed that this parameter was best correlated with the extent of WML. CONCLUSION: In addition to the absolute level of blood pressure, systolic circadian blood pressure variation and in particular a systolic nighttime blood pressure increase may play an important role in the pathogenesis of WML.