Relationship between orthostatic hypotension and cognitive impairment in the elderly
Introduction
Dementia represents one of the main neurological disorders leading to loss of autonomy in the elderly. Considering this major public health issue, therapeutic and preventive strategies must be found. In the past decade several studies have implicated hypertension as a risk factor not only for vascular dementia (VaD) but also for degenerative dementia such as Alzheimer's disease (AD) [1], [2], [3]. Postural change in blood pressure (BP) increases with advancing age [4]. The prevalence of orthostatic hypotension (OH) in the elderly population ranges from 4% to 33%, depending on comorbidities and the definition of OH [5]. Arterial aging and age-related changes in the autonomic nervous system are involved in the hemodynamic response to orthostatic challenge in the elderly [6]. A decline in baroreceptor sensitivity, reduced sympathetic nervous system activation with the uncoupling of beta-adrenergic receptors to orthostatic challenge, a diminished vasomotor response to sympathetic nervous system activation, and a decline in the vestibulosympathetic reflex with aging all play a role in the onset of OH in the elderly [7]. With aging, there is a progressive reshape of cerebral autoregulation from a sigmoid curve to a straight line. This implies that any abrupt change in BP will result in a rapid and significant change in cerebral blood flow (CBF) [6]. Few studies, to date, have examined the relationship between OH and cognitive decline and their results have been contradictory [8], [9], [10]. The aim of this study was to examine the association between OH and cognitive function in elderly people.
Section snippets
Methods and study population
The study group was part of a cohort of elderly subjects with complaints of memory loss attending a geriatric memory clinic. We included 495 consecutive elderly outpatients from this cohort. Patients with major depressive states, psychiatric deficits, confusion, or types of dementia other than AD and VaD were excluded. All the subjects gave written informed consent for their participation in the study which was approved by the local ethics committee.
Statistical analysis
Results in the tables and text are expressed as mean ± standard deviation (SD) and as mean ± standard error (SE) in figures. A chi-square test was used for the group comparisons of qualitative variables and an analysis of variance (ANOVA) was performed for quantitative variables. An analysis of covariance (ANCOVA) was used to compare CEP scores between groups including confounding variables as covariates. A multivariate regression analysis was used to assess the relationship between OH and
Results
The population included 495 subjects, mean age 76 ± 8 years and 72% were female. Prevalence of OH was 14% (n = 69/495). Hypertension (SBP and/or DBP ≥ 140/90 mm Hg and/or use of antihypertensive drug) was seen in 74% of patients (n = 366/495) with mean values of SBP/DBP (143 ± 24/79 ± 13 mm Hg). Antihypertensive therapy was used by 55% of people of the overall sample (n = 272/495). Diabetes mellitus was present in 7% of the patients (n = 35/495) and hyperlipidemia in 36% (n = 178/495).
Table 1 shows the baseline
Discussion
We demonstrated a significant association between OH and cognitive function in elderly subjects. Our cross-sectional data revealed that in this cohort, subjects with OH showed poorer cognitive function. This relationship was independent of age, education level, seated SBP/DBP, weight and antihypertensive drugs. Interestingly, OH was associated not only with VaD but also of AD.
The prevalence of OH that we showed in this cohort is in agreement with other studies performed in an elderly ambulatory
Acknowledgments
The authors are grateful to the patients and their relatives for cooperating in this research study.
References (33)
- et al.
Midlife blood pressure and dementia: the Honolulu–Asia aging study
Neurobiol Aging
(2000) - et al.
15-year longitudinal study of blood pressure and dementia
Lancet
(1996) - et al.
Relation of neurocardiovascular instability to cognitive, emotional and functional domains
Arch Gerontol Geriatr
(2007) - et al.
The age-dependent relation of blood pressure to cognitive function and dementia
Lancet Neurol
(2005) - et al.
Blood pressure regulation in Alzheimer's disease
J Auton Nerv Syst
(1994) - et al.
Pulse pressure and pulse wave velocity are related to cognitive decline in the Baltimore Longitudinal Study of Aging
Hypertension
(2008) Intraindividual variability in postural blood pressure in the elderly
Clin Sci
(1985)- et al.
Cognitive and functional status of the oldest old
J Am Geriatr Soc
(1997) - et al.
Risk factors for vascular dementia: hypotension as a key point
Vasc Health Risk Manage
(2008) - et al.
Aging attenuates the vestibulosympathetic reflex in humans
Circulation
(2002)
Orthostatic hypotension and cognitive decline in older people
J Am Geriatr Soc
Orthostatic hypotension, hypotension and cognitive status: early comorbid markers of primary dementia?
Dement Geriatr Cogn Disord
The Consensus Committee of the American Autonomic Society and the American Academy of Neurology
Neurology
The cognitive efficiency profile: description and validation in patients with Alzheimer disease
Int J Geriatr Psychiatr
Diagnostic and statistical manual of mental disorders
Clinical diagnosis of Alzheimer's disease: report of the NINCDS-ADRDA Work Group under the auspices of the Department of Health and Human Services Task Force on Alzheimer's Disease
Neurology
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