Sensory, motor function predicts early cognitive impairment in older adults

Older adults with impaired sensory and motor function are at greater odds of early cognitive impairment (ECI), according to study results published in Alzheimer’s and Dementia. However, improvements in multisensory, fine motor, and gross motor function reduced the odds of ECI, which may help guide future interventions aimed at reducing the incidence of ECI.

Age-related sensory and motor impairments have previously been linked to a higher risk for mild cognitive impairment and Alzheimer Disease. Existing research indicates that these impairments are potential preclinical indicators of MCI, AD, and related dementias, and therefore may be important targets for early intervention. Recent findings suggest that individuals with concurrent sensory and motor impairments face an elevated risk for cognitive impairment, emphasizing the need for a comprehensive understanding of their combined impact.

To this aim, investigators conducted a cross-sectional study using data from the Baltimore Longitudinal Study of Aging (BLSA) to assess the association between sensory and motor function and ECI combined. The investigators used a battery of measurements to evaluate multisensory (ie, hearing, vision, vestibular, vestibular, proprioception, and olfaction), fine motor, and gross motor function. Additionally, the investigators used demographically adjusted cutoff points for the Card Rotations Test and the California Verbal Learning Test (CVLT) immediate recall to assess ECI.

A total of 650 individuals were included in the final analysis. On average, the sample was 73.8 (SD, 10.3) years of age, 57.1% were women, and 25.5% identified as Black. The investigators found that 153 individuals met the ECI criteria, and these individuals tended to be younger (P =.006) than the individuals without ECI (n=497). Sensory and motor function did not significantly differ between the groups.

In adjusted models, the investigators found that the odds of ECI decreased with each unit (1 SD) increase in multisensory (32%), fine motor (30%), and gross motor (12%) function. Following additional adjustments for comorbid health conditions, the likelihood of ECI was reduced by 32%, 29%, and 10% for every unit increase in multisensory, fine motor, and gross motor attributes, respectively. However, there were no significant differences in individual sensorimotor indicators between individuals with and without ECI.

In confirmatory factor analysis, the investigators observed correlations between multisensory and fine motor factors (r, 0.77), multisensory and gross motor factors (r, 0.81), and fine motor and gross motor factors (r, 0.74).

Study authors concluded, “The primary goal of our work is to guide future research studies that are aimed to prevent or intervene on cognitive decline at an early stage through modifiable mechanisms, allowing older adults to maintain independence and overall quality of life.”

Study limitations include the potential lack of generalizability due to a healthy and highly educated cohort, and an inability to determine causality given the cross-sectional design.

By Hibah Khaja, PharmD

References:

Sayyid ZN, Wang H, Cai Y, et al. Sensory and motor deficits as contributors to early cognitive impairment. Alzheimers Dement. Published online February 20, 2024. doi:10.1002/alz.13715