Abstract 188: Total And Frontal Lobe White Matter Hyperintensity Volume And Impaired Mobility Among Older Adults
Introduction: Gait speed is associated with multiple adverse outcomes of aging. White matter hyperintensities (WMH) on magnetic resonance imaging (MRI) have been associated with gait speed, though few studies have examined changes in gait speed over time, regional localization of WMH, or enrolled participants community-based studies and in ethnic/racial minorities. We examined the association between a decline in gait speed and total and regional WMH volumes in a community-based study of aging.
Methods: Participants were enrolled in the Washington Heights Inwood Columbia Aging Project (WHICAP), a cohort of Medicare recipients residing in Northern Manhattan. At enrollment participants underwent a comprehensive medical evaluation, as well as neuropsychological testing and assessment of gait speed via a 4 meter walk test. An MRI sub-study was started in 2004, at which time participants underwent a second gait speed measurement (mean 4.7 [SD=0.5] years apart). Odds ratios (OR) and 95% confidence intervals (CI) were calculated to examine the associations of large (defined as one standard deviation above the age-expected mean) WMH volume and regional WMH volumes (as a continuous measure) with the primary outcome (transition from normal to abnormal gait speed, defined as < 0.4 meters/second) using logistic regression. Analyses were adjusted for socio-demographic factors, clinical history of stroke, hypertension, diabetes, body mass index, the presence of mild cognitive impairment or dementia, the length of time between the two physical performance measures, and the initial gait speed measure.
Results: A total of 758 participants in WHICAP underwent MRI and two measures of gait speed. At the time of MRI the mean age was 80.3 (SD=5.6) and 114 (14.4%) had a large WMH volume. Large WMH volume was associated with a transition to an abnormal gait speed between the two visits (adjusted OR 3.09, 95% CI=1.21-7.93). Total frontal WMH volume (adjusted OR 1.06, 95%CI=0.93-1.20), or other regional volumes, were not associated with a transition to an abnormal gait speed between the two gait speed measurements.
Conclusion: Total, but not regional, WMH are associated with slowing of gait over time. Modification of the known risk factors associated withWMH presents a potential strategy for the prevention of gait speed decline.
- © 2012 by American Heart Association, Inc.