Orthostatic hypotension as a risk factor for stroke - The atherosclerosis risk in communities (ARIC) study, 1987-1996

Background and Purpose-The association between orthostatic hypotension (OH) and stroke has rarely been investigated in longitudinal studies. The purpo se of the present study was to determine whether OH predicts ischemic strok e in a middle-aged, biethnic population after adjustment for known stroke r isk factors. Diastolic, systolic, and consensus OH were evaluated for basel ine associations and for the ability to predict stroke. Methods-In 11 707 persons from the Atherosclerosis Risk in Communities (ARI C) cohort who were free of stroke and overt heart disease at baseline, Cox proportional hazards analyses modeled the association between OH at baselin e and incident ischemic stroke over 7.9 years of follow-up. OH was defined as a systolic blood pressure drop greater than or equal to 20 mm Hg (systol ic OH), a diastolic blood pressure drop greater than or equal to 10 mm Hg ( diastolic OH), or a drop in either (consensus OH) when a person changed fro m a supine to standing position. Results-OH was predictive of ischemic stroke, even after adjustment for num erous stroke risk factors (consensus OH: hazard ratio. 2.0; 95% CI, 1.2 to 3.2). While the baseline characteristics associated with OH varied dependin g on the type of OH, all types of OH had a similar risk of stroke. Conclusions-OH is an easily obtained measurement that may help to identify middle-aged persons at risk for stroke.