Orthostatic hypotension and cognitive decline in older people

OBJECTIVES: To establish the role of orthostatic hypotension (OH) as a risk factor for cognitive decline among home-dwelling and institutionalized older people and to describe other predictors of cognitive decline. DESIGN: Follow-up study with two clinical examinations. SETTING: A community-based setting in northern Finland. PARTICIPANTS: All of the 1159 people aged 70 or more living in five rural municipalities around the town of Oulu in Northern Finland in 1991. At the time of the follow-up examination, 2.5 years later, 884 of the original participants were alive and 651 were re-examined. MEASUREMENTS: In 1991, 907 people (78.3 % of the total population) were tested for orthostatic hypotension, and their cognitive capacity was assessed with the Mini-Mental State Examination (MMSE). The calculation/spelling tasks were excluded from the final version used in the statistical analysis. The re-assessment of cognitive capacity was made on 651 subjects (73.6% of those alive) who had participated in the first examination. The data were analyzed using polychotomous and linear regression analysis models. RESULTS: The prevalence of OH was 28.7%, with no age or sex differences. The mean sum score for the shortened MMSE in 1991 was 21.6 (+/-3.98) for persons with OH and 21.1 (+/-4.08) for non-OH persons. During the follow-up, the sum score declined in the OH group by .44 (+/-2.81) points and in the non-OH group by .83 (+/-3.61) points. No type of OH (systolic or diastolic 1- or 3-minute values or their combination) predicted cognitive decline; the only predictors were old age and low level of formal education. CONCLUSIONS: Orthostatic hypotension is a common clinical condition that affects every fourth person aged 70 years or older. By temporarily inducing cerebral hypoperfusion, it may cause or exacerbate cognitive dysfunction. In an unselected population, OH was not associated with cognitive deterioration, nor did it predict cognitive decline during a 2-year follow-up.