Walking speed as an aging biomarker in baboons (Papio hamadryas)

Abstract

Background: Walking speed is an important human aging biomarker. Baboons are valuable translational models for aging studies. Establishing whether walking speed is a good aging biomarker has value. We hypothesized there would be characteristic age-related decline in baboon walking speed.

Methods: We studied 33 female baboons aged 5-21 years. Walking speed was calculated by the time to walk between landmarks separated by known distances. A regression model was developed to describe the relationship between speed, age, and body weight.

Results: Speed negatively associated with age, a relationship enhanced by increased weight (P < 0.0005). For 16-kg animals, speed declined approximately 0.6 cm/s yearly. For each additional kilogram of weight, speed declined an additional 0.3 cm/s yearly.

Conclusions: Baboon walking speed declines with age, an effect modulated by weight. Ease of measurement and strong age association make walking speed a valuable biomarker for aging research with this important experimental species.

Keywords: age-related decline; gait speed; non-human primates; physical mobility.

Figure 1

Contour plot of mean speed as it changes with weight and age. The blue closed shape shows where most of the data points lie, on the two-dimensional weight and age continuum (the star is an older animal who is quite lighter than her peers). As animals age, they tend to gain weight (at least those in this study, many of whom are obese); that combination leads to the reduction in walking speed.