The correlation of plasma Aβ42 levels, depressive symptoms, and cognitive function in the Korean elderly.

Objectives: This study aims to investigate whether plasma amyloid beta 1-42 (Aβ42) levels are associated with depressive symptoms and/or cognitive function in community dwelling elderly.

Methods: Subjects were 123 participants of a population-based project designed to screen community dwelling elderly older than 65 years old in Gangwon Province, Korea, for the early detection of depression and dementia. Symptoms of depression were assessed using the SGDS-K (Short Geriatric Depression Scale-Korean version), and the MMSE-KC (Mini-Mental State Examination-Korean version) was used to assess cognitive function. Plasma Aβ42 levels were measured with the human amyloid beta ELISA Kit.

Results: The elderly with depressive symptoms (SGDS-K score ≥ 8) had higher plasma Aβ42 levels than those without depressive symptoms (SGDS-K score<8) (p<0.1). Plasma Aβ42 levels were positively correlated with SGDS-K scores (p<0.05). However, MMSE-KC scores were inversely associated with plasma Aβ42 levels (p<0.01). Plasma β42 levels were also associated with MMSE-KC (F=8.07, p<0.01) and SGDS-K (F=4.53, p<0.05) by generalized linear model (GLM) with controlling age, sex and education.

Conclusion: Plasma Aβ42 levels were associated with depressive symptoms and cognitive function in community dwelling elderly. The present study supports the possibility that plasma Aβ may be involved in the development of late onset depression.