Author(s): SHI, Y., OHBAYASHI, K., SATOU, A., NAKAMURA, K., SAWADA, S., HARADA, S., SAKURAI, S., MACHIDA, S., Institution: JUNTENDO UNIVERSITY, Country: JAPAN, Abstract-ID: 1216

INTRODUCTION:
Depressive symptoms are common in later life and substantially contribute to morbidity and reduced quality of life¹. In older adults, lower activity levels and poorer physical performance are frequently associated with greater depressive symptom burden², and mild cognitive impairment (MCI) has also been linked to reduced physical function³. However, evidence focusing specifically on older adults with MCI remains limited, and it is unclear which physical function components are independently associated with depressive symptoms after accounting for habitual exercise. Therefore, in this study we examined associations between physical function indicators and depressive symptoms in older adults with MCI.
METHODS:
Community-dwelling older adults were recruited through local organizations. MCI was defined by an education-adjusted Montreal Cognitive Assessment-Japanese version score of 18–25. Depressive symptoms were assessed using the Geriatric Depression Scale-15 (GDS-15). Physical performance measures included handgrip strength, the 30-s chair stand test (CS-30), and usual gait speed. Covariates included sex, age, body mass index (BMI), chronic disease status, and exercise frequency (days/week category). Negative binomial regression with a log link estimated incidence rate ratios (IRRs) and 95% confidence intervals (CIs).
RESULTS:
Among 108 older adults with MCI, mean age was 76.6 ± 6.7 years, 56.5% were female, and mean BMI was 22.6 ± 2.8 kg/m². The mean GDS-15 score was 2.04 ± 2.22. In fully adjusted models, higher gait speed and higher exercise frequency were independently associated with lower GDS-15 scores. Each 0.1 m/s increase in gait speed was associated with a lower GDS-15 score (IRR = 0.888, 95% CI 0.810–0.974, p = 0.012), and higher exercise frequency was similarly associated with lower GDS-15 scores (IRR = 0.730, 95% CI 0.573–0.931, p = 0.011). Handgrip strength and CS-30 were not significantly associated with GDS-15 scores. Sensitivity analyses using gait speed tertiles (reference: fastest tertile) showed a significant overall tertile effect (p < 0.001). Compared with the fastest tertile, the intermediate tertile had higher depressive symptom burden (IRR = 2.494, 95% CI 1.455–4.274, p < 0.001), whereas the slowest tertile did not differ significantly (IRR = 1.300, 95% CI 0.628–2.690, p = 0.480).
CONCLUSION:
In older adults with MCI, gait speed and exercise frequency were independently associated with GDS-15 scores, whereas handgrip strength and CS-30 were not after adjustment. These findings indicate that mobility-related performance and habitual exercise may be clinically relevant markers when evaluating depressive symptoms in MCI. Longitudinal studies are required to clarify directionality and underlying mechanisms.

1.WHO. Mental health of older adults.
2.Mura et al. Physical activity in depressed elderly. A systematic review.
3.Fuentes et al. Functional parameters indicative of mild cognitive impairment: a systematic review using instrumented kinematic assessment.