New research assessing the significance of gait speed as a measure of health suggests that it should be viewed as an integrative measure of health that may originate in childhood. The conclusion significantly expands the long-standing interpretation of gait speed as an index of functional decline.

Two well-known Duke psychologists, Avshalom Caspi, PhD, and Terrie E. Moffitt, PhD, are among the authors of an original investigation published in October 2019 in JAMA Network examining the association of neurocognitive and physical function with gait speed in midlife.

The study concluded that gait speed is a summary index of lifelong aging with possible origins in childhood central nervous system deficits—one key to understanding why walking speed is such a powerful indicator of the risk of disability and death in the elderly. The research was conducted in conjunction with Duke’s Claude D. Pepper Older Americans Independence Center.

“There is a tendency to adopt the idea that gait speed is just a musculoskeletal measure,” says Caspi. “But we are learning that gait involves much more. Not just lung and cardio involvement, but also the brain. It’s a measure of more than fragility—this data is telling us about the entire body,” he adds. “Sure, we may learn how fragile an individual is through these tests, but we are also learning about the vigor of the brain.”

The study was conducted with participants from the Dunedin Multidisciplinary Health & Development Study, a long-running cohort of 1,037 people born in 1972 and 1973 in Dunedin, New Zealand. The researchers tested gait speed using several techniques in approximately 1,000 45-year-old participants and assessed participants’ physical and cognitive functioning. Their brains were imaged with MRIs.

Because the participants’ neurocognitive functions had been tested as children in the Dunedin study, researchers were able to establish a link between childhood brain health and gait speed at midlife.

Among the highlights of the research:

• Predicting future disability with gait speed testing has proven effective because of its accurate assessment of lifelong vulnerability in both body and brain.
• Testing gait speed provides information about ways in which the brain is aging as well as the body.
• Measuring gait speed may be an effective way to evaluate new clinical trials that attempt to slow aging. These trials could involve younger participants.

Walking speed has long been used to predict functional decline and mortality in geriatric populations. A 2011 JAMA meta-analysis of 35,000 adults confirmed the correlation between mortality and gait speed.

The latest study contributes to ongoing research emphasizing ways to slow the aging process, Caspi says. “This study and others like it are part of the growing geroscience field of research,” he adds. “There’s always been a sense that that all diseases are caused by aging. Rather than combat the diseases individually, maybe we can tackle aging itself. How do we arrest the aging process?”

The Dunedin Connection

Caspi and Moffitt began working together with the Dunedin cohort as post-doctoral psychologists. They continue to publish research on human development and aging and work regularly in New Zealand to continue the longitudinal research project. The Dunedin study is now in its fifth decade and has produced more than 1,200 publications and reports, many of which have influenced or helped inform global policy makers.