The Relationship between Late-Life Depression and Cognitive Function in Older Korean Adults: A Moderation Analysis of Physical Activity Combined with Lower-Body Muscle Strength

Abstract

Background: This study examined the relationship of physical activity (PA) combined with lower-body muscle strength to late-life depression and cognitive impairment in 10,097 participants (6062 females) ≥ 65 years of age. Methods: Exposures were PA, sit-to-stand test (STST), and depressive symptoms. Outcome was cognitive performance. Results: Depressed individuals had an increased risk of mild cognitive impairment (MCI; odds ratio (OR), adjusted OR = 1.845 and 95% confidence interval (CI) = 1.580–2.154, p < 0.001) compared with non-depressed individuals. Individuals who had insufficient PA and a poor STST and either insufficient PA or a poor STST had an increased risk of MCI (adjusted OR = 1.329 and 95% CI = 1.209–1.46, p < 0.001 and adjusted OR = 2.822 and 95% CI = 2.488–3.200, p < 0001, respectively) compared with individuals who had sufficient PA and a good STST. A significant moderation effect of PA combined with lower-body muscle strength on the relationship between depression and cognitive function was observed (β = −1.3923; 95% CI = −2.1505 to −0.6341, p < 0.003). Conclusions: The negative effect of late-life depression on cognitive function was incremental in the order of sufficient PA and a good STST, insufficient PA or a poor STST, and insufficient PA and a poor STST.

The association between the Short Physical Performance Battery and longitudinal trajectories of depressive symptoms among Chinese older adults

“…It has been observed that depressed patients often experience a decline in physical function, reflected in a decrease in SPPB scores. 22,23 A cross-sectional study revealed an association between SPPB levels and depression. 24 However, this previous study had limitations due to its crosssectional design, and further longitudinal investigations were necessary to establish a causal relationship.…”

“…The SPPB test includes measures of lower limb muscle strength, speed, and balance, which provide a comprehensive assessment of the lower limb physical performance in older adults. It has been observed that depressed patients often experience a decline in physical function, reflected in a decrease in SPPB scores 22,23 …”

Depressive Symptomatology as a Predictor of Cognitive Impairment: Evidence from the Korean Longitudinal Study of Aging (KLOSA), 2006–2020

“…Although depressive symptoms are frequently regarded as being prodromal indicators of clinical dementia, mounting evidence suggests that depressive symptoms in later stages of life may act as an independent risk factor for cognitive impairment [29]. Previous Korean studies have consistently demonstrated that depressive symptoms are associated with the development of cognitive impairment during advanced age [5,30,31]. Vascular diseases and elevated glucocorticoid levels have been postulated as representing a causal link between depression and cognitive impair-ment [10].…”