Orthostatic hypotension associated with executive dysfunction in mild cognitive impairment.

Introduction: Midlife hypertension is associated with dementia in longitudinal studies while chronic hypotension in the elderly is associated with dementia onset. Orthostatic hypotension could influence cognitive performance in the elderly. The objective of this study was to assess the relationship between orthostatic hypotension and cognitive functions.

Methods: Consecutive participants with complete neuropsychological evaluation from a Memory Clinic were included. Orthostatic hypotension (OH) was defined by a fall≥20/10mmHg systolic/diastolic pressure. Participants were classified into one of 3 groups: 1) subjective cognitive impairment (SCI), 2) mild cognitive impairment (MCI), and 3) dementia. Neuropsychological tests were analyzed for patients with and without OH.

Results: One hundred and twenty participants were included, of which 16 (13%) were classified as SCI, 42 (35%) as MCI, and 63 (52%) with dementia. Prevalence of OH was 0% for the SCI group, 26% (n=11) for the MCI group, and 38% (n=24) for the dementia group. Age, sex, education, and brief cognitive test scores (MMSE & MoCA) were not different between groups with or without OH. In the MCI group, OH was associated with lower cognitive performance in several executive functions tests: visual working memory (p<0.001), processing speed (p=0.006), Stroop flexibility (p=0.030) and Trail-Making Test part B (p=0.024). There was no difference in episodic memory performance. OH was associated with a diagnosis of hypertension and the use of antihypertensive medication. No differences were observed in vascular brain injury between groups with and without OH.

Conclusions: This study found that orthostatic hypotension prevalence is correlated to severity of cognitive deficits in a Memory Clinic. In MCI, OH is associated with lower performance in executive functions. OH could represent an under-recognized correlate of cognitive performance.