Cognitive health risks posed by social isolation and loneliness in older Korean Americans

Exploring the differential impacts of social isolation, loneliness, and their combination on the memory of an aging population: A 6-year longitudinal study of the CLSA

Memory plays a crucial role in cognitive health. Social isolation (SI) and loneliness (LON) are recognized risk factors for global cognition, although their combined effects on memory have been understudied in the literature. This study used three waves of data over six years from the Canadian Longitudinal Study on Aging to examine whether SI and LON are individually and jointly associated with memory in community-dwelling middle-aged and older adults (n = 14,208). LON was assessed with the question: "In the last week, how often did you feel lonely?". SI was measured using an index based on marital/cohabiting status, retirement status, social activity participation, and social network contacts. Memory was evaluated with combined z-scores from two administrations of the Rey Auditory Verbal Learning Test (immediate-recall, delayed-recall). We conducted our analyses using all available data across the three timepoints and retained participants with missing covariate data. Linear mixed models were used to regress combined memory scores onto SI and LON, adjusting for sociodemographic, health, functional ability, and lifestyle variables. Experiencing both SI and LON had the greatest inverse effect on memory (least-squares mean: -0.80 [95 % confidence-interval: -1.22, -0.39]), followed by LON alone (-0.73 [-1.13, -0.34]), then SI alone (-0.69 [-1.09, -0.29]), and lastly by being neither lonely nor isolated (-0.65 [-1.05, -0.25]). Sensitivity analyses confirmed this hierarchy of effects. Policies developed to enhance memory in middle-aged and older adults might achieve greater benefits when targeting the alleviation of both SI and LON rather than one or the other individually.

Examining the Combined Effects of Social Isolation and Loneliness on Memory: A Systematic Review

BACKGROUND

Some research suggests social isolation and loneliness are important risk factors for reduced successful aging and cognitive health. However, findings are inconsistent and no prior systematic review has investigated whether social isolation and loneliness are associated with the memory domain of cognition. This review examined whether social isolation and loneliness individually and jointly affected the memory of middle- and older-aged adults.

METHODS

We used PubMed, PsycInfo, and Scopus to search for comparative studies that examined the impact of both loneliness and social isolation (e.g., social activity, social networks) on memory (including all subtypes) in populations aged ≥ 45 years. Three raters performed data extraction and risk of bias assessment using the Joanna Briggs Institute checklist. Data were synthesized narratively following the Synthesis without Meta-Analysis guideline.

RESULTS

In 12 included articles, higher levels of loneliness and social isolation (combining a range of different indicators) were associated with lower memory performance, where the interaction between loneliness and social isolation had the largest adverse effect on memory, followed by social isolation alone, and followed by loneliness alone. However, substantial heterogeneity was observed in the composition of the two most common indicators of social isolation (social network size, social activity participation), with the magnitude of most results being clinically non-important. Most articles had moderate risk of bias.

CONCLUSION

This review found an inverse association between social isolation/loneliness and memory, and outlines future steps to systematically combine the two constructs and measure social isolation in a consistent, multi-modal format.

Addressing Psychosocial Factors in Cognitive Impairment Screening from a Holistic Perspective: The DeCo-Booklet Methodology Design and Pilot Study

Cognitive impairment (CI), an intermediate phase between the decline in physiological cognition and dementia, is known to be mediated by a variety of risk and protective factors, with age being the most influential of these. The multifactorial nature of CI and the worldwide phenomenon of an aging population makes decoupling old age from disease through the concept of healthy aging (HA) a matter of major interest. Focusing on psychosocial variables and psychological constructs, here we designed and piloted a data collection booklet (DeCo-B) to assess CI and HA from a holistic perspective. The DeCo-B comprises six sections: sociodemographic factors, CI, meaning in life, psychosocial factors, health problems, and lifestyle. The estimated prevalence of CI and HA in our cohort were 24.4% and 6.6%, respectively. Spearman correlations mainly identified pairwise associations between the meaning in life domains and psychosocial variables. Moreover, age, marital status, purpose in life, resilience, chronic pain, cognitive reserve, and obstructive sleep apnea were significantly associated with an increased risk of CI. Our results showed that DeCo-B is a suitable tool for researching how modifiable risk and protective factors influence cognitive status. The complex interrelationships between variables should be further investigated and, for practical reasons, the questionnaire should be optimized in future work.