Association between social isolation and subjective cognitive decline in Korean older adult population: A nationwide cross-sectional study in South Korea

This study aimed to analyze the association between social isolation (SI) and subjective cognitive decline (SCD) in Koreans aged 65 years or older. The cross-sectional study of the Korea Community Health Survey (KCHS) was conducted on 72,904 individuals aged 65 years or older. SI was defined using five indicator, and an increasing number of SI indicators signifies a higher level of SI. SCD was defined as self-observed impairment of more frequent or worsening memory loss or confusion within the previous 12 months. The cognitive function questionnaire included questions regarding SCD. Chi-square test and weighted logistic regression analysis were used to analyze the association between SI and SCD. SI group had higher odds of SCD experience rate than the non-SI (AOR:1.15, 95 % CI: 1.08–1.22). Subgroup analysis showed that when SI occurred in the non-Moderate or Vigorous Physical Exercise (MVPE) group, SI group was more likely to experience SCD compared with the non-SI (AOR: 1.17, 95 % CI: 1.10–1.25). However, when SI occurred in the MVPE group, there were not find out the association between SI and SCD. The results of this study showed that the SI group had a higher rate of SCD than the non-SI group. Particularly, a strong association was observed in the non-MVPE. Therefore, even if SI occurs, SCD can be prevented by educating individuals regarding the importance of participating in MVPE and depression.