Overweight/obesity and gait abnormality: what role does the brain play in the relationship?

Gait is related to weight factors and regulated by the nervous system. Emerging evidence indicates that adiposity impacts brain health. This study explores the relationship between anthropometric indices and gait performance, and investigates the role of brain parameters in the relationship.

This study included 710 community-dwelling older adults from the Taizhou Imaging Study. Nine anthropometric indices were calculated to assess body weight using standard formulas based on measured height, weight, waist circumference (WC), and hip circumference. Gait assessment includes Timed-Up-and-Go tests, Tinetti tests, and quantitative gait assessment conducted with wearable insole devices. 16 quantitative parameters were summarized into five independent gait domains (rhythm, symmetry, phase, pace and variability) using factor analysis. Quantitative susceptibility mapping was used to measure iron levels in cortical regions.

Overweight/obesity group (body mass index, BMI ≥ 24 kg/m²) had significantly poorer performance in the phase domain (standardized β = -0.172, P = 0.023), specifically manifested in the percentage of the double support time (standardized β = 0.783, P = 0.028) and stance time (standardized β = 0.422, P = 0.019). They also exhibited higher iron levels of the inferior temporal gyrus (ITG) (standardized β = 0.641, P = 0.021). The metabolic-related anthropometric indices have stronger associations with gait performance and indices of abdominal assessment more closely correlated with iron levels. The iron levels of ITG mediated the association of anthropometric indices (BMI, WC, Waist-to-Height Ratio, abdominal volume index and body roundness index) with the phase domain, with mediation proportions ranging from 8.95% to 13.45%.

Increased anthropometric indices are associated with relative prolongation of the stance phase and the iron levels of ITG mediates the associations. Our research offers valuable insights into the neuropathological mechanisms underlying of gait abnormalities in the community-dwelling older adults with overweight/obesity.