Gait Performance Trajectories and Incident Disabling Dementia Among Community-Dwelling Older Japanese

Objectives: Initial gait speed is a good predictor of dementia in later life. This prospective study used repeated measures analysis to identify potential gait performance trajectory patterns and to determine whether gait performance trajectory patterns were associated with incident disabling dementia among community-dwelling older Japanese.

Design: A prospective, observational, population-based follow-up study.

Setting: Japan, 2002 to 2014.

Participants: A total of 1686 adults without dementia (mean [SD] age, 71.2 [5.6] years; women, 56.3%) aged 65 to 90 years participated in annual geriatric health assessments during the period from June 2002 through July 2014. The average number of follow-up assessments was 3.9, and the total number of observations was 6509.

Measurements: Gait performance was assessed by measuring gait speed and step length at usual and maximum paces. A review of municipal databases in the Japanese public long-term care insurance system revealed that 196 (11.6%) participants developed disabling dementia through December 2014.

Results: We identified 3 distinct trajectory patterns (high, middle, and low) in gait speed and step length at usual and maximum paces in adults aged 65 to 90 years; these trajectory patterns showed parallel declines among men and women. After adjusting for important confounders, participants in the low trajectory groups for gait speed and step length at usual pace were 3.46 (95% confidence interval 1.88-6.40) and 2.12 (1.29-3.49) times as likely to develop incident disabling dementia, respectively, as those in the high trajectory group. The respective values for low trajectories of gait speed and step length at maximum pace were 2.05 (1.02-4.14) and 2.80 (1.48-5.28), respectively.

Conclusions: Regardless of baseline level, the 3 major trajectory patterns for gait speed and step length tended to show similar age-related changes in men and women in later life. Individuals with low trajectories for gait speed and step length had a higher dementia risk, which highlights the importance of interventions for improvements in gait performance, even among older adults with low gait performance.