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

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.