Orthostatic hypotension and cognition in older adults: A systematic review and meta-analysis

Background: Orthostatic hypotension (OH) is common in older adults with reported prevalence rates of 5-40%. A direct link between OH and cognitive performance has been proposed due to impaired vascular autoregulation. Aim: To systematically assess the literature of the association between OH and cognitive performance in older adults. Methods: Literature search of MEDLINE, Embase, Cochrane Central Register of Controlled Trials and PsycINFO from inception to May 2017. Studies were included if OH and cognition were assessed in subjects of mean or median age >= 65 years. Risk of bias was assessed with the Newcastle Ottawa Scale. Results: Of 3266 studies screened, 32 studies (22 cross-sectional; 10 longitudinal) reporting data of 28,980 individuals were included. OH prevalence ranged from 3.3% to 58%. Of the 32 studies, 18 reported an association between OH and worse cognitive performance and 14 reported no association. Mini Mental State Examination (MMSE) was the most commonly used cognitive assessment tool. Studies using more than one cognitive assessment tool were more likely to find an association between OH and worse cognition. OH was significantly associated with a lower MMSE mean score (mean difference - 0.51 (95% CI: -0.85, -0.17, p = 0.003)) and an increased risk of cognitive impairment (OR 1.19 (95% CI, 1.00-1.42, p = 0.048)). Conclusions: OH is common in older populations and is associated with worse cognition expressed as lower MMSE scores. Use of MMSE alone as a cognitive assessment tool may underestimate the association. It is yet unclear whether the association between OH and worse cognitive performance is causative.