39. APATHY IS ASSOCIATED WITH GAIT VELOCITY IN A SOUTH INDIAN COMMUNITY DWELLING COHORT

Abstract

Introduction

Apathy is frequently seen in neuropsychiatric diseases, including Parkinson disease and Alzheimer dementia, and may also be an independent risk factor for the development of motoric-cognitive risk syndrome (MCR). Existing literature on apathy has focused on community-dwelling cohorts from highly developed nations, such that the generalizability of work identifying a link between apathy and motoric-cognitive outcomes has not been fully demonstrated.

Methods

N=742 older adults were recruited from urban and rural areas in Kozhikode district, Kerala, India to participate in this cross-sectional study to examine the relationship between apathy, MCR, cognitive impairment, and other demographic characteristics. Apathy was assessed using the Apathy Evaluation Scale, and depression was measured with the Geriatric Depression Scale. MCR was defined as cognitive complaints and slow gait, with gait speed assessed as 1 SD below age- and sex-adjusted norms. Statistical analyses, including bivariate and regression models, were conducted to evaluate associations between apathy, gait velocity, and MCR using SPSS software.

Results

Compared with subjects in the lowest apathy tertile, those in the highest tertile were older (69.9 vs 67.5 years, p LESS THAN 0.0001), less physically active (0.9 vs 1.5 active days per week, p LESS THAN 0.05), in worse subjective general health (p LESS THAN 0.05) and had slower gait (74.9 vs 81.4 cm/s, p LESS THAN 0.005). High-apathy subjects also had lower ACE scores (79.3 vs 84.3, p LESS THAN 0.0001) and higher GDS scores (9.6 vs 5.6, p LESS THAN 0.0001), but not higher levels of dysphoria (p=0.1519). Before adjustment, apathy was found to negatively correlate with gait velocity (β = -0.112, p≤0.005), and this relationship was principally moderated by ACE score. Although subjects with MCR had higher levels of apathy compared to those without MCR (34.6 vs 31.4, p LESS THAN 0.01), prevalent MCR and apathy tertile were not significantly associated in logistic regression models.

Conclusions

Among community-dwelling older adults in Kerala, apathy is inversely associated with gait velocity but not prevalent MCR, and the former relationship is moderated by degree of cognitive impairment, as determined by ACE score. These findings suggest that apathy may exist on a continuum with gait slowing, MCR, and clinically significant dementia, but future longitudinal studies will be needed to determine a temporal relationship.