Submitted to: PLoS One
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 10/10/2012
Publication Date: 11/21/2012
Citation: Heffernan, K.S., Manini, T., Blair, S., Hsu, F., Nicklas, B., Kritchevsky, S., Newman, A.B., Sutton-Tyrrell, K., Church, T., Haskell, W., Karas, R., Kuvin, J., Fielding, R.A. 2012. Relation of pulse pressure to long-distance gait speed in community-dwelling older adults: Findings from the LIFE-P study. PLoS One. 7(11):e49544. Interpretive Summary: The American Heart Association encourages all Americans to “Start Moving”, but as we get older our arteries may be sabotaging our attempts. As we age our arteries become stiffer and this increases risk for cardiovascular disease. Increases in artery stiffness may also limit our ability to move by increasing work performed by the heart and reducing blood flow to the muscles. In this study, we examined the relationship between walking speed and pulse pressure. Pulse pressure is a nice inexpensive way to measure artery health. When getting your blood pressure measured by a doctor, pulse pressure is calculated as the higher value (systolic blood pressure) minus the lower value (diastolic blood pressure). As we get older pulse pressure increases and this is due to increases in artery stiffness. According to findings from this study, older adults with higher pulse pressure (stiffer arteries) tend to walk slower than older adults with lower pulse pressure (less stiff arteries). This finding is important because it suggests that aging arteries may alter our ability to walk. Future research will be needed to see if things that keep our arteries young (active lifestyle, proper diet, certain medications) improve our ability to walk. After all, “…we are only as old as our arteries.” – Sir William Osler c. 1898.
Technical Abstract: Reduced long-distance gait speed, a measure of physical function, is associated with falls, late-life disability, hospitalization/institutionalization and cardiovascular morbidity and mortality. Aging is also accompanied by a widening of pulse pressure (PP) that contributes to ventricular-vascular uncoupling. The purpose of this study was to test the hypothesis that PP is associated with long-distance gait speed in community-dwelling older adults in the Lifestyle Interventions and Independence for Elders Pilot (LIFE-P) study. Brachial blood pressure (by auscultation and sphygmomanometry) and 400-meter gait speed (average speed maintained over a 400-meter walk at “usual” pace) were assessed in 424 older adults between the ages of 70-89 yrs (mean age = 77 yrs; 31% male). PP was calculated as systolic blood pressure – diastolic blood pressure. Patients with a history of heart failure and stroke (n = 42) were excluded leaving 382 participants for final analysis. When categorized into tertiles of pulse pressure, participants within the highest pulse pressure tertile had significantly slower gait speed than those within the lowest pulse pressure tertile (p<0.05). Following stepwise multiple regression, pulse pressure was significantly and inversely associated with 400-meter gait speed (p<0.05). Other significant predictors of gait speed included: handgrip strength, body weight, age and history of diabetes mellitus (p<0.05). Mean arterial pressure, systolic blood pressure and diastolic blood pressure were not predictors of gait speed. Pulse pressure is a predictor of long-distance gait speed in community-dwelling older adults. These findings suggest that vascular senescence and altered ventricular-vascular coupling may contribute, in part, to the deterioration of mobility with advancing age.