Brain over muscle: central mechanisms predominate in gait impairment among older adults with type 2 diabetes mellitus

Background: Gait impairment is common in older adults with type 2 diabetes mellitus (T2DM). This complication increases risk of falls, disability, and mortality. Although gait disorders are often associated with peripheral deficits, emerging evidence suggests that central mechanisms may play an important role. The relative contributions of central and peripheral factors across gait parameters remain unclear. Methods: In this cross-sectional study, gait parameters were assessed using wearable inertial sensors in 41 older adults with T2DM and 55 age-matched controls. Central factors included medial temporal atrophy (MTA) on magnetic resonance imaging (MRI) and global cognition (MoCA/MMSE). Grip strength was used as the index of peripheral function. Hierarchical regression quantified the incremental variance explained by central versus peripheral factors after adjusting for demographic and vascular confounders. Results: < 0.001). For gait speed, central factors (MTA and cognition) explained most of the model's explained variance, whereas grip strength explained little and was not an independent predictor. Both central and peripheral factors contributed independently to cadence. Conclusion: Hippocampal atrophy and cognitive dysfunction are independently associated with slowed gait speed in the elderly with T2DM. Cadence reflects combined effects of central and peripheral influences. These findings suggest that future intervention research should explore a shift toward from traditional peripherally focused approaches to brain-centered strategies for maintaining motor ability in the future. These findings are cross-sectional and associative; causal inferences require longitudinal validation.