Apolipoprotein E Genotype Linked to Spatial Gait Characteristics: Predictors of Cognitive Dual Task Gait Change

<div><p>Background</p><p>Developing measures to detect preclinical Alzheimer’s Disease is vital, as prodromal stage interventions may prove more efficacious in altering the disease’s trajectory. Gait changes may serve as a useful clinical heuristic that precedes cognitive decline. This study provides the first systematic investigation of gait characteristics relationship with relevant demographic, physical, genetic (Apolipoprotein E genotype), and health risk factors in non-demented older adults during a cognitive-load dual task walking condition.</p><p>Methods</p><p>The GAITRite system provided objective measurement of gait characteristics in APOE-e4 “carriers” (n = 75) and “non-carriers” (<i>n</i> = 224). Analyses examined stride length and step time gait characteristics during simple and dual-task (spelling five-letter words backwards) conditions in relation to demographic, physical, genetic, and health risk factors.</p><p>Results</p><p>Slower step time and shorter stride length associated with older age, greater health risk, and worse physical performance (<i>p</i>s < .05). Men and women differed in height, gait characteristics, health risk factors and global cognition (<i>p</i>s < .05). APOE-e4 associated with a higher likelihood of hypercholesterolemia and overall illness index scores (<i>p</i>s < .05). No genotype-sex interactions on gait were found. APOE-e4 was linked to shorter stride length and greater dual-task related disturbances in stride length.</p><p>Conclusions</p><p>Stride length has been linked to heightened fall risk, attention decrements and structural brain changes in older adults. Our results indicate that stride length is a useful behavioral marker of cognitive change that is associated with genetic risk for AD. Sex disparities in motor decline may be a function of health risk factors.</p>