Self-reported physical activity and gait in older adults without dementia: A longitudinal study.

BACKGROUND AND AIMS

Physical activity (PA) is associated with higher gait speed. We aimed to examine the associations between PA and change in spatial and temporal gait measures as well as fall risk in community-dwelling individuals free of dementia.

METHODS

Longitudinal study among 4173 individuals aged ≥50 years (mean age 71 years; 2078 males; median follow-up 4 years) enrolled in the Mayo Clinic Study of Aging. Self-reported late-life PA was used to calculate overall PA and moderate-vigorous PA (MVPA) scores. Gait was assessed using GAITRite® and Zeno™ systems. Incident falls information was based on diagnostic codes retrieved from medical records. We ran linear mixed effects models to examine associations between z-scored PA variables and longitudinal gait parameters, adjusted for age, sex, education, body mass index (BMI), medical comorbidities, and including interactions between PA and time since baseline. In secondary analyses, we calculated Cox Proportional hazard models with age as time scale predicting incident falls by PA, adjusting for sex, education, BMI, medical comorbidities, and falls history.

RESULTS

At baseline, higher PA was associated with higher velocity (overall PA: estimate 2.9935; MVPA: 2.2961;  < 0.001), higher cadence (overall PA: 1.0665; MVPA: 0.9073;  < 0.001), greater stride length (overall PA: 2.0805; MVPA: 1.4726;  < 0.001), shorter double support time (overall PA: -0.0257; MVPA: -0.0205;  < 0.001), and lower stance time variability (overall PA: -0.0204,  < 0.001; MVPA: -0.0152;  = 0.006). Overall PA was longitudinally associated with less decline in cadence, and MVPA with less increase in intraindividual stance time variability. Overall PA (Hazard ratio 0.892, 95% confidence interval 0.828-0.961,  = 0.003) and MVPA (HR 0.901; 95% CI 0.835-0.973,  = 0.008) were associated with a decreased risk of incident falls.

CONCLUSION

Late-life PA was associated with favorable gait outcomes and decreased risk of incident falls. Thus, late-life PA may help to maintain gait performance and decrease fall risk in old age.