CHANGES OF CIRCADIAN BLOOD-PRESSURE PATTERNS ARE ASSOCIATED WITH THE OCCURRENCE OF LACUNAR INFARCTION

Background: The occurrence of lacunar infarction is closely related to arterial hypertension. However, there is only limited and partly cont roversial knowledge regarding the possible pathogenetic role of circad ian blood pressure changes. Objective: To evaluate the relationship be tween circadian blood pressure rhythm, occurrence, and extent of lacun ar infarction. Methods: We analyzed circadian blood pressure patterns, other cardiovascular risk factors, and occurrence of lacunar infarcti on in 118 hospitalized patients older than 55 years. Noninvasive 24-ho ur blood pressure measurements and magnetic resonance or computed tomo graphic brain imaging were performed in 61 patients with lacunar infar ction and in 57 control patients. Daytime blood pressure variability w as defined as the within-subject SD of all systolic and diastolic bloo d pressure readings during the daytime measurement period. Circadian b lood pressure variation was defined as the average percentage change o f nighttime blood pressure values compared with the daytime blood pres sure values. Results: Patients with lacunar infarction were significan tly older and showed more often a history of arterial hypertension, el evated average daytime blood pressure values, an increased systolic da ytime blood pressure variability, and a reduced circadian blood pressu re variation due to an increased incidence of a pathologic nighttime b lood pressure increase. No significant correlation was found between t hese parameters and the number of lacunae. A logistic regression analy sis revealed that a reduced systolic circadian blood pressure variatio n, age, systolic average daytime blood pressure, and a history of arte rial hypertension were best correlated with the occurrence of lacunar infarction. Conclusion: Reduced nighttime decline in systolic blood pr essure may be an important risk factor for the development of lacunar infarction in addition to the absolute level of blood pressure and age .