title: Orthostatic Hypotension and the Long-Term Risk of Dementia: A Population-Based Study.
abstract: BACKGROUND
  Orthostatic hypotension (OH) is a common cause of transient cerebral hypoperfusion in the population. Cerebral hypoperfusion is widely implicated in cognitive impairment, but whether OH contributes to cognitive decline and dementia is uncertain. We aimed to determine the association between OH and the risk of developing dementia in the general population.
  
  
  RESULTS
  Between 4 October 1989 and 17 June 1993, we assessed OH in non-demented, stroke-free participants of the population-based Rotterdam Study. OH was defined as a ≥20 mm Hg drop in systolic blood pressure (SBP) or ≥10 mm Hg drop in diastolic blood pressure (DBP) within 3 min from postural change. We furthermore calculated within participant variability in SBP related to postural change, expressed as coefficient of variation. Follow-up for dementia was conducted until 1 January 2014. We determined the risk of dementia in relation to OH and SBP variability, using a Cox regression model, adjusted for age; sex; smoking status; alcohol intake; SBP; DBP; cholesterol:high-density lipoprotein ratio; diabetes; body mass index; use of antihypertensive, lipid-lowering, or anticholinergic medication; and apolipoprotein E genotype. Finally, we explored whether associations varied according to compensatory increase in heart rate. Among 6,204 participants (mean ± standard deviation [SD] age 68.5 ± 8.6 y, 59.7% female) with a median follow-up of 15.3 y, 1,176 developed dementia, of whom 935 (79.5%) had Alzheimer disease and 95 (8.1%) had vascular dementia. OH was associated with an increased risk of dementia (adjusted hazard ratio [aHR] 1.15, 95% CI 1.00-1.34, p = 0.05), which was similar for Alzheimer disease and vascular dementia. Similarly, greater SBP variability with postural change was associated with an increased risk of dementia (aHR per SD increase 1.08, 95% CI 1.01-1.16, p = 0.02), which was similar when excluding those who fulfilled the formal criteria for OH (aHR 1.08, 95% CI 1.00-1.17, p = 0.06). The risk of dementia was particularly increased in those with OH who lacked a compensatory increase in heart rate (within lowest quartile of heart rate response: aHR 1.39, 95% CI 1.04-1.85, p-interaction = 0.05). Limitations of this study include potential residual confounding despite rigorous adjustments, and potentially limited generalisability to populations not of European descent.
  
  
  CONCLUSIONS
  In this population predominantly of European descent, OH was associated with an increase in long-term risk of dementia.
authors.affiliation: Department of Epidemiology, Erasmus Medical Centre, Rotterdam, the Netherlands.|Department of Neurology, Erasmus Medical Centre, Rotterdam, the Netherlands.
authors.forename: Frank J
authors.initials: FJ
authors.lastname: Wolters
authors.affiliation: Department of Geriatrics, Erasmus Medical Centre, Rotterdam, the Netherlands.
authors.forename: Francesco U S
authors.initials: FU
authors.lastname: Mattace-Raso
authors.affiliation: Department of Neurology, Erasmus Medical Centre, Rotterdam, the Netherlands.
authors.forename: Peter J
authors.identifier: http://orcid.org/0000-0003-4998-9609
authors.initials: PJ
authors.lastname: Koudstaal
authors.affiliation: Department of Epidemiology, Erasmus Medical Centre, Rotterdam, the Netherlands.|Department of Epidemiology, Harvard T.H. Chan School of Public Health, Boston, Massachusetts, United States of America.
authors.forename: Albert
authors.initials: A
authors.lastname: Hofman
authors.affiliation: Department of Epidemiology, Erasmus Medical Centre, Rotterdam, the Netherlands.|Department of Neurology, Erasmus Medical Centre, Rotterdam, the Netherlands.|Department of Radiology, Erasmus Medical Centre, Rotterdam, the Netherlands.
authors.forename: M Arfan
authors.initials: MA
authors.lastname: Ikram
mesh_terms: D000368:Aged; D003704:Dementia / Q000209:etiology*; D005260:Female; D005500:Follow-Up Studies; D006801:Humans; D007024:Hypotension, Orthostatic / Q000150:complications*; D008297:Male; D018570:Risk Assessment