Frequency and prognostic implications of orthostatic hypotension and white matter hyperintensities in older people with mild dementia

Abstract

Background: In addition to cognitive impairments, dementia sufferers may have other problems as well, such as depression and orthostatic hypotension (OH), both of which according to previous studies may be associated with white matter hyperintensities (WMH). WMH are a common finding on magnetic resonance imaging (MRI) scans of the brains of older people. Aims: To study the frequency and some potential prognostic implications of OH and WMH in a sample of older people with mild to moderate dementia. Materials and methods: The subjects of the four substudies are participants in the DemVest study; a prospective cohort study which from March 2005 to April 2007 included consecutive referrals to secondary care outpatient clinics in old age psychiatry and geriatric medicine in western Norway with mild dementia. Dementia and dementia subtypes were diagnosed according to standardised criteria. The comprehensive baseline assessment included brain MRI, blood tests and orthostatic blood pressure measurements, followed by annual examinations. Results: OH was found to be significantly more common in patients with mild dementia than in normal controls (41 % vs. 14%), and dementia was an independent predictor of OH. From baseline to the 4-year follow-up, 30 to 45% had OH. Having persistent OH did not seem to predict a less favourable course with respect to cognition, daily functioning, or survival. No association was found between OH and WMH load. Baseline WMH load was positively correlated with baseline severity of depressive symptoms, and appeared to be associated with persistent and incident depression at 1 year. Conclusions and implications: OH was common in mild dementia, but was not associated with an unfavourable course or a higher WMH load. However, depressive symptoms were positively associated with the WMH load. Nevertheless, due to its association with falls, and potential for treatment, OH should be actively looked for. The potential prognostic implications of WMH for depression and the etiology of WMH in dementia deserve further attention in future studies.