The impact of cognitive impairment on the physical ageing process

Physical decline and cognitive degeneration characterise the ageing process.

Physical parameters, performance and the functional indexes were studied in relation to age in healthy and cognitively impaired older persons to understand the interactions and changes during normal ageing, cognitive decline and progression to frailty.

Cross-sectional analysis was performed on a data registry of an ambulatory Memory Diagnosis Centre. The quantitative gait characteristics at usual pace, body composition parameters, disability scales (activity of daily living and instrumental activity of daily living) and Rockwood frailty index were compared in cognitively healthy (CHI), mild cognitively impaired, mildly and moderately demented < 80-years old and > 80-years old adults.

Quality of gait deteriorated with age in CHI and cognitively impaired. Skeletal muscle mass index decreased when cognitive status worsened. Disability and frailty correlated with increasing cognitive impairment. Age, gender, cognitive impairment, body composition and Rockwood's Frailty scale had a combined forecasting effect, as well as the individual effect on the gait characteristics. Disability score, Frailty index, skeletal muscle mass and skeletal muscle mass index, gait speed, normalised mean step length and swing time variability in mildly demented < 80-years old adults mirrored the parameters in the CHI > 80-years old.

Quantitative gait characteristics, muscle mass and disabilities change along with cognitive impairment, frailty and age. A more rapid physical ageing process accompanies cognitive decline. Therefore, gait characteristics should be age-referenced and studies on gait in older persons should include muscle mass, frailty and cognitive parameters.