Orthostatic hypotension, dizziness, neurology outcomes, and death in older adults

To test the hypothesis that orthostatic hypotension (OH) might cause cerebral hypoperfusion and injury, we examined the longitudinal relationship between OH or orthostatic symptoms and incident neurologic outcomes in a community population of older adults.

Cardiovascular Health Study participants (≥65 years) without dementia or stroke had blood pressure (BP) measured after lying down for 20 minutes and after standing 3 for minutes. Participants reported dizziness immediately upon standing and any dizziness in the past 2 weeks. OH was defined as a drop in standing systolic/diastolic BP ≥20/≥10 mm Hg. We determined the association between OH or dizziness with (1) MRI brain findings (ventricular size, white matter hyperintensities, brain infarcts) using linear or logistic regression, (2) cognitive function (baseline and over time) using generalized estimating equations, and (3) prospective adjudicated events (dementia, stroke, death) using Cox models. Models were adjusted for demographic characteristics and OH risk factors. We used multiple imputation to account for missing OH or dizziness (n = 534).

Prior to imputation, there were 5,007 participants (mean age 72.7 ± 5.5 years, 57.6% women, 10.9% Black, 16% with OH). OH was modestly associated with death (hazard ratio [HR] 1.11; 95% confidence interval 1.02-1.20), but not MRI findings, cognition, dementia, or stroke. In contrast, dizziness upon standing was associated with lower baseline cognition (β = -1.20; -1.94 to -0.47), incident dementia (HR 1.32; 1.04-1.62), incident stroke (HR 1.22; 1.06-1.41), and death (HR 1.13; 1.06-1.21). Similarly, dizziness over the past 2 weeks was associated with higher white matter grade (β = 0.16; 0.03-0.30), brain infarcts (OR 1.31; 1.06-1.63), lower baseline cognition (β = -1.18; -2.01 to -0.34), and death (HR 1.13; 1.04-1.22).

Dizziness was more consistently associated with neurologic outcomes than OH 3 minutes after standing. Delayed OH assessments may miss pathologic information related to cerebral injury.