The relationship between 24-hour blood pressure readings, subcortical ischemic lesions and vascular dementia.

BACKGROUND: Twenty-four-hour blood pressure (BP) readings have been found to correlate with hypertensive target organ damage. Lacunar infarcts (LI) and white matter lesions (WML) probably represent manifestations of cerebral hypertensive target organ damage. This study was conducted to better delineate the relationships between 24-hour BP measurements, LI/WML and small vessel disease cognitive impairment/vascular dementia (CI/VD). METHODS: Two hundred patients with first-time symptomatic LI were examined with 24-hour BP monitoring. The degree of nocturnal BP dip, (daytime BP - nighttime BP)/daytime BP, was categorized into three groups: dippers (>0.1), nondippers (0-0.1) and reverse dippers (<0). WML were subdivided into periventricular hyperintensities (PVH) and subcortical hyperintensities. RESULTS: The breakdown of patients was: 50% nondippers, 27.5% reverse dippers and 22.5% dippers. Forty-one patients (20.5%) were found to have CI and dementia. Male sex (OR 3.35; 95% CI 1.20-9.34), advanced PVH (OR 14.42; 95% CI 5.62-36.98) and absence of a dipping status (nondipper: OR 12.62; 95% CI 1.37-115.95; reverse dipper: OR 11.95; 95% CI 1.27-112.11) were independently associated with CIVD after multivariate analysis. High nighttime systolic BP (OR 3.93; 95% CI 1.38-11.17), high daytime (OR 2.06; 95% CI 1.03-4.04) and nighttime diastolic BP (OR 2.48; 95% CI 1.13-5.45) and absence of a dipping status (nondipper: OR 2.7; 95% CI 1.03-7.05; reverse dipper: OR 3.78; 95% CI 1.38-10.34) were significantly associated with PVH. CONCLUSIONS: High prevalence of a nondipping status was found in the LI cohort. A nondipping status appears to be directly associated with CIVD independent of PVH. This study indicates the need for further studies to investigate whether or not controlling nighttime BP will help reduce the risk for CI/VD development.