FACTORS ASSOCIATED WITH CHANGES IN GAIT SPEED IN OLDER ADULTS

Background. The study addressed whether changes in gait speed in commu nity-dwelling older adults were associated with changes in fitness (st rength and aerobic capacity), physical health status, and/or depressiv e symptoms. Methods. The study sample comprised 152 community-dwelling adults aged 68-85 who had participated in an exercise study. Study me asures at baseline and 6-month follow-up included gait speed, a leg st rength score, maximal aerobic capacity (VO(2)max), CES-Depression scal e, and physical health status (SIP Physical Dimension). Results. In cr oss-sectional regression analyses, leg strength, VO(2)max, weight, and the strength by VO(2)max interaction term were significant independen t predictors of gait speed (R(2) = 26%). Based upon the observed 7% in crease in VO(2)max and 8% increase in strength in the exercise groups, the regression model predicted only a 2% (1.5 m/min) increase in gait speed, which did not differ significantly from the observed increase of 0% (.32 m/min). The strongest correlate of change in gait speed was change in CES-D scores (partial R = -.37). Change in physical health status also correlated with change in gait speed (partial R = -.28), w hile change in fitness did not. Conclusions. The results suggest, in t he range of fitness of the study sample, that changes in gait speed ar e related to changes in depressive symptoms and physical health status , but not to modest changes in fitness. A model assuming nonlinear rel ationships may be appropriate for understanding how strength and aerob ic capacity affect gait speed.