The Relationship Between Dipping Profile in Blood Pressure and Neurologic Deficit in Early Acute Ischemic Stroke

Abstract

Blood pressure (BP) in healthy individuals exhibits a diurnal variation, with a nighttime dip of 10%-20%. A persistently high nighttime BP is associated with increased cardiovascular morbidity. The effects of diurnal BP variations on the neurologic deficit in acute stroke at presentation and in the first few weeks poststroke are unclear. We hypothesized that persistently elevated BP results in poor outcome. Patients with an acute ischemic stroke presenting within 48 hours of onset underwent 24-hour ambulatory monitoring of systolic, diastolic, and mean BP. There were a total of 35 patients (16 males; mean age, 74 ± 14 years). The percentage change between mean day and night BP classified patients into dippers (> 10% change), nondippers (0-10% change), or reverse-dippers (< 0% change). The Scandinavian Stroke Scale (SSS) and the National Institute of Health Stroke Scale (NIHSS) were assessed on admission, at week 1, and at week 3. The relationship between neurologic score and dipping classification was analyzed using analysis of variance and analysis of covariance, with age and baseline score as covariates. Based on both the SSS and NIHSS, the reverse-dippers had the lowest neurologic scores at baseline, week 1, and week 3, followed by the nondippers. The dippers performed the best in comparison. No significant differences in demographics and/or other BP characteristics among the groups that could account for these differences in outcome were noted. A reverse-dipping profile in diastolic BP was associated with poor neurologic state at baseline and weeks 1 and 3 compared with both dippers and nondippers.