The association between orthostatic hypotension and cognition and stroke: a meta-analysis of prospective cohort studies.

Many studies have indicated that orthostatic hypotension (OH) may be a risk factor for dementia and stroke, but the results have been inconsistent. To further ascertain the links between OH and cognition or stroke, a meta-analysis was performed. The Chinese Biomedical Database, PubMed, Web of Science, and the Cochrane Library database were searched (up to March 2019) to identify prospective cohort studies that examined the associations between OH and the risks of stroke and dementia among adult populations. Subgroup analyses and meta-regression analyses were conducted to identify sources of heterogeneity. We also performed Begg's test and Egger's test to assess publication bias. A total of 3490 articles were identified, and 18 prospective observational cohort studies were ultimately included. Among these studies, eight prospective studies were about stroke, nine studies were about cognition and one study reported data about both stroke and dementia. Meta-analysis revealed an association between OH and worse cognition (hazard ratio (HR): 1.18, 95% confidence interval (CI): 1.03-1.35, I = 69.5%). For dementia, the pooled HR was 1.30, with 95% CI: 1.14-1.48, I = 31.0%. In addition, we found that OH was associated with a higher risk of stroke (HR: 1.36, 95% CI = 1.17-1.57, I = 67.3%). No publication bias was detected. This meta-analysis provides evidence that OH was associated with worse cognition. OH accounted for a 30% increase in the risk of dementia and a 36% increase in the risk of stroke.