Subclinical cardiovascular disease and changes in self-reported mobility: Multi-ethnic study of atherosclerosis

Abstract

Background: We examined associations of three markers of subclinical cardiovascular disease (intimal-medial thickening, coronary artery calcification, and ankle-brachial index) with changes in self-reported walking over time. Methods: Data were from 6,490 Multi-Ethnic Study of Atherosclerosis participants (aged 45–84 years), free of clinical cardiovascular disease at baseline. Outcomes, assessed four times over 11 years, included self-reported walking pace (none to striding pace; score, 0–4) and total walking time (minutes/week). Linear generalized estimating equation models estimated associations of baseline intimal-medial thickening (zscored), coronary artery calcification (Agatston units), and ankle-brachial index (ratio of ankle-to-arm systolic blood pressure) with walking pace and walking time modeled continuously in separate analyses. Results: Median follow-up was 9.2 years (maximum, 11.4). Walking pace (estimate, −0.042 points [95% CI; −0.048, −0.036], p < 0.0001) and walking time (estimate, −4.71 minutes [95% CI: −8.54, −0.88], p = 0.016) decreased yearly. Greater baseline intimal-medial thickening related to faster decline in walking pace in multivariable analyses: walking pace score decreased 0.004 points (95% CI: −0.008, −0.001) more per year for each 1-SD higher intimal-medial thickening z-score, equivalent to an additional 10% slower yearly walking. Greater coronary artery calcification was associated with slower walking but inconsistently related to decline in walking pace. Higher ankle-brachial index was associated with faster baseline walking pace (estimate, 0.043 points [95% CI: 0.027, 0.059] per 1-SD) but unrelated to changes in walking pace. Cardiovascular disease measures were unrelated to total walking time. Conclusions: Greater subclinical cardiovascular disease is associated with prevalent slower self-reported walking pace in middle-aged and older adults but has limited impact on changes in walking over time.