Physical Activity and Cognitive Function in Mild Cognitive Impairment

Physical exercise has been associated with enhanced memory formation and consolidation in patients with mild cognitive impairment (MCI). This study aimed to investigate the relationship between objective neuropsychological performances and continuously recorded physical activity. A cut-off value of measured physical activity was used to differentiate early-stage and late-stage MCI. Fifty-four patients with MCI were included. The relationship between cognitive function and measures of daily activity measured by continuous three-axis accelerometers in Xiaomi Mi Band, including subject-level average step counts, average distance (kilometers), and average calorie expenditure per day of 7-day activity, was determined. The slope of the receiver operating characteristic curve was used to determine the measures of activity to draw comparisons between early-stage MCI and late-stage MCI. The patients were assessed by using several cognitive tests such as Cognitive Abilities Screening Instrument and Chinese Version Verbal Learning Test. The multivariate linear regression model indicated a significant correlation of higher average step counts per day of 7-day activity (aver-step-counts) with higher score in visual construction (β = 0.355; p = .015). To differentiate patients with late-stage MCI from those with early-stage MCI, the cut-off value of 6,284 steps on aver-step-counts showed an optimal sensitivity and specificity (Youden index = 0.36, area under the curve = 0.651, p = .042). The aver-step-counts showed a significantly better differentiating rate between patients with early-stage and late-stage MCI than average calorie expenditure per day of 7-day activity did (p = .046). Accelerometer-determined measures of activity patterns show as potential measurement to reflect cognitive function.