Abstract MP06: Gait Speed is Associated with Subclinical and Clinical Atherosclerosis - Analysis from the AGES Reykjavik Study
Background: Coronary events are major causes of morbidity and mortality in the population and are consequences of atherosclerotic coronary artery disease. The development of atherosclerosis is a long standing process. Measuring subclinical atherosclerosis allows examination of the determinants of the disease without using hard end points. We studied the functional ability of individuals measured as gait speed and its relationship with prevalent subclinical atherosclerosis and incident coronary events.
Material and Methods: Participants were from the AGES Reykjavik Study, a population study of 5174 men and women (57%), mean age 76.5 (SD 5.5) followed for coronary events (MI, PCI, CABG) for a median of 8.1 years. Subclinical atherosclerosis (IMT and plaque) was examined with ultrasound of the carotid arteries and Agatston score of coronary artery calcium (CAC) by CT at entry into the study. Gait speed was measured by time of 6 m walk. Cox proportional hazard was used to assess the effect of gate gait speed, on CHD events, verified from hospital records. Logistic regression was used to estimate the association of subclinical CHD to atherosclerosis, adjusted for baseline age, sex and CHD risk factors.
Results: There was a gradual increase in risk of CHD by quintile of 6m walk speed with HR of 2.0 (95% CI 1.7 - 2.4) in the top compared to bottom quintile adjusted for age and sex. After further adjustment for conventional risk factors attenuation to a HR of 1.8 (95% CI 1.5 - 2.2) was seen. When the subclinical markers was examined, there was a gradual increase in CAC by slower gate speed (p< 0.0001), much more pronounced in men, who had higher CAC than women. Similar picture was seen for plaque (p <0.0001) in the carotid arteries, but a statistically significant association was not found for IMT (p=0.09).
Conclusion: Gait speed is strongly associated with manifest CHD in this population of free living old people. When subclinical measurements of arterial disease are used, those clearly measuring atherosclerosis - CAC and plaque of the carotid - are associated with worse gait speed. On the other hand gait speed was not associated with IMT, which much less clearly reflects atherosclerosis. The simple physical performance test, of the time it takes to walk 6 m used in this study, captured clinical CHD and subclinical cardiovascular status measured by imaging. This simple performance measurement might therefore be of potential use for peripheral practitioner in selecting those individuals who might benefit from detailed cardiovascular assessment.
Author Disclosures: V. Gudnason: None. K. Siggeirsdottir: None. L.J. Launer: None. T.B. Harris: None. T. Aspelund: None.
- © 2014 by American Heart Association, Inc.