Relationship between subjective memory complaint and executive function in a community sample of South Korean elderly

The aim of this study was to investigate the association between subjective memory complaint (SMC) and executive function in a community sample of South Korean elderly.

Data for 1442 non-cognitive impaired elderly individuals aged 65 and over were selected from a nationwide dementia epidemiological study conducted in South Korea. Global cognitive function was assessed by the Korean version of the Mini-Mental State Examination (MMSE-KC). The registration and recall subscales of the MMSE were used for evaluating memory function. Executive function was measured by using the Initiation/Perseveration (IP) subscale of the Korean dementia rating scale (K-DRS).

Of the 1442 participants, 1088 were in the normal control group and 354 were in the SMC group. In the SMC group, compared to the normal control group, the proportion of depression was significantly higher, total MMSE scores, delayed recall score and total IP scores were significantly lower, and the mean scores of complex/simple verbal IP, alternating movements, and graphomotor design were lower. In the unadjusted linear regression model, the SMC significantly associated with a lower score of total MMSE-KC, MMSE delayed recall, K-DRS IP, complex/simple verbal IP, alternating movements and graphomotor design. After adjusting for age, gender, education, marital status, alcohol consumption, smoking behaviour, and depression, the SMC were significantly associated with lower total MMSE score, MMSE delayed recall, K-DRS IP, and K-DRS complex/simple verbal IP.

In this population-based sample, individuals with SMC had evidence of lower performance on global cognition, memory function, and executive function, especially verbal fluency, after adjusting for demographic variables and depression.