MedWire News: Study findings indicate that elderly people who are generally functioning well but who can only walk relatively slowly may be up to three times as likely to die from cardiovascular (CV) causes as those who can walk faster.
The increased risk for CV death was seen in both genders, in different elderly age groups, in those with or without a high-risk vascular profile, and those with low or usual physical activity, report Alexis Elbaz (University of Paris, France) and colleagues in the British Medical Journal.
The researchers investigated the relationship of walking speed with mortality, overall and according to main causes of death, in 3208 well functioning individuals aged 65 years or older who were enrolled in the Three-City study. These people did not have a prevalent condition strongly associated with decreased walking speed, such as coronary artery disease, stroke, Parkinson’s disease, dementia, or hip fracture history, at baseline.
Among baseline assessments, each participant underwent a maximum walking speed test in which they were asked to walk as fast they could without running down a corridor. A chronometer with detectors placed 6 meters apart recorded their walking speed in distance over time.
Over 5 years and 16,414 person years of follow-up, 209 participants died, 99 from cancer, 59 from CV disease, and 51 from other causes.
Kaplan-Meier analysis showed that overall mortality was significantly higher among participants in the lowest third of baseline maximum walking speed than among those with higher baseline walking speeds, with curves diverging after 20–30 months (p<0.001). Mortality did not differ between the higher two thirds, however.
The increased cumulative risk in the lowest third of walking speed was also seen for CV death (p<0.001) and other causes of death (p=0.004), but there was no significant increase in cancer deaths with lower walking speed.
In multivariable analysis adjusted for age, gender, CV risk factors, and other covariates associated with walking speed, the lowest third of walking speeds was associated with a 2.92-fold increased risk for CV death relative to the upper two thirds.
The association with CV mortality was significant in analyses stratified by gender, age, body mass index, and self-reported level of physical activity.
The findings show “the role of fitness in preserving life and function in older age is important,” say the authors.
In an accompanying editorial Rowan Haywood (Nottingham University, UK) and Simon Conroy (University of Leicester, UK) note that including walking speed in any screening test could have drawbacks in practice not least because of the many potential confounding and reverse causal factors and that, as with all classic risk factors, walking speed in isolation is of limited use in predicting disease at the individual level.
They add: “Preventing vascular disease is important, especially for older people who are well. But as old age progresses, there is a trade off between preventing disease and the burden of polypharmacy, and the priority shifts from preventing mortality to predicting and forestalling transitions to disability.”
MedWire (www.medwire-news.md) is an independent clinical news service provided by Current Medicine Group, a trading division of Springer Healthcare Limited. © Springer Healthcare Ltd; 2009
Free abstract
