Korean Social Life, Health, And Aging Project Research Articles

Association between Loneliness and Memory Function through White Matter Hyperintensities in Older Adults: The Moderating Role of Gender.

Loneliness has an important impact on memory function in late life. However, the neural mechanism by which loneliness detrimentally influences memory function remains elusive. Furthermore, it remains unclear whether the association between loneliness and memory function varies by gender. The current study aimed to investigate the neural mechanism underlying the association between loneliness and episodic memory function and explore whether it varies with gender among cognitively normal older adults. A total of 173 community-dwelling adults aged 60 years or older from the Korean Social Life, Health, and Aging Project (KSHAP) study (mean age = 71.87) underwent an assessment of loneliness, neuropsychological testing, and structural magnetic resonance imaging. The association between loneliness and episodic memory function was mediated by the volume of white matter hyperintensities (WMHs), but not by hippocampal or gray matter volumes. In addition, the association between loneliness and memory function through WMHs was significantly moderated by gender; specifically, the indirect effect was significant among men but not among women. The study suggests that WMHs may be a potential neurological mechanism that causes late-life memory dysfunction associated with loneliness in older men. The findings underscore the need for gender-specific interventions to mitigate memory impairment associated with late-life loneliness, with significant public health implications.

A Prospective Sociocentric Study of 2 Entire Traditional Korean Villages: The Korean Social Life, Health, and Aging Project (KSHAP).

The Korean Social Life, Health, and Aging Project (KSHAP) was a multidisciplinary prospective study conducted in South Korea that measured various health biomarkers from blood, hair, and brain magnetic resonance imaging, and we examined their associations with sociocentric (global) social network data of older adults in 2 entire villages (or cohorts). Cohort K included participants aged 60 years or older, and cohort L included participants aged 65 years or older. We performed a baseline survey involving 814 of the 860 individuals (94.7% response rate) in cohort K in 2012 and 947 of the 1,043 individuals (90.8% response rate) in cohort L in 2017. We gathered longitudinal data for 5 waves in cohort K from 2011 to 2019 and 2 waves in cohort L from 2017 to 2022. Here, we describe for the first time the follow-up design of the KSHAP, the changes in social networks, and various biomarkers over a number of years. The data for cohort K are publicly available via the Korean Social Science Data Archive as well as the project website, and the data for cohort L will be shared soon.

Late‐life social activity moderates the association between temporal lobe atrophy and episodic memory decline

AbstractBackgroundRetirement and loss of important social relationships, including spouse and friends, make older adults more vulnerable to social isolation. Therefore, social activity could be important for older adults in maintaining life satisfaction and everyday functioning. Although several studies found protective roles of social activity against cognitive decline in late life, only a few studies examined the protective effects of social activity using longitudinal data. In this study, the effects of social activity on the relationship between brain aging and cognitive decline in older adults were examined during a four‐year period.MethodThirty‐two older adults with normal cognition (mean age = 70.69, SD: 6.27, mean education = 7.75, SD: 3.94 at baseline) were recruited from the Korean Social Life, Health, and Aging Project (KSHAP). Neuropsychological and brain imaging data, and social survey, were acquired in 2015 and 2019. Elderly Verbal Learning Test (EVLT) performance and cortical volumes from Magnetic Resonance Imaging (MRI) were the main measures of interest. The participants were asked to respond either “yes” or “no” to social survey items, including participation in community senior center events, volunteering for charities, religious activities, socializing events, leisure activities, and community activities. Social activity was explored in terms of level, consistency, and types of social activities. The Computational Anatomy Toolbox (CAT) was used to calculate temporal lobe gray matter volume selected as regions of interest (ROI) for its role in episodic memory. Hierarchical regressions were conducted to examine the effects of social activity on the relationship between temporal lobe atrophy and episodic memory decline.ResultWe found that the temporal lobe atrophy was associated with the delayed recall decline (r = 0.49, p = 0.003). More involvement in social activity at baseline decreased the effects of temporal lobe atrophy on delayed recall decline, controlling for age, sex, education, and self‐rated health as covariates. Further, consistent involvement in social activity, especially volunteering, attenuated the association between temporal lobe atrophy and delayed recall decline.ConclusionThese findings suggest that social activities in late life function as cognitive reserve to buffer against the effects of temporal lobe atrophy on episodic memory decline in older adults.

Social Network Characteristics Predict Loneliness in Older Adults

Introduction: Social isolation is detrimental to late-life health outcomes. Although objective social isolation is a major source of perceived loneliness, how different layers of social disconnection systematically constitute the subjective experience of loneliness remains unclear. Methods: This study focused on older adults who participated in the Korean Social Life, Health, and Aging Project (KSHAP) (n = 1,724; mean age = 72.91 years) and examined how the proximal and distal characteristics of social networks predict loneliness using a hierarchical linear regression model. The study also investigated whether the major loss of social roles (marital and working status) influences perceived loneliness through the proximal and distal aspects of social networks by cross-sectional mediation analysis. Results: This study found that the proximal (subjective number of connections) and distal (brokerage and embeddedness) aspects of social networks additively explained the frequency of loneliness. Moreover, the loss of late-life social roles (marital and working status) was related to an increase in loneliness, where the distal characteristic of social networks mediated this relationship. Discussion/Conclusion: The results of this study suggest that the proximal and the distal characteristic of social networks is a social determinant predicting loneliness in late life. Besides, the loss of bridging and cohesive position among community networks may be a critical pathway to psychosocial transition after marital and working status changes.

Gender differences in the longitudinal association between husbands' and wives' depressive symptoms among Korean older adults: the moderating effects of the spousal relationship.

The mutual effects of depressive symptoms between couples have long been reported; however, it remains unknown whether the spousal concordance in depressive symptoms differs depending on spousal relationships. Data on 291 married couples from the Korean Social Life, Health, and Aging Project (KSHAP) were examined. The KSHAP collected global network data from the target population living in one Korean village over eight years and across five waves. A seemingly unrelated regression (SUR) model in the panel data was employed to address correlations and heterogeneity. If one spouse (husband or wife) had depressive symptoms, the other spouse tended to have depressive symptoms. However, the effect of marital relations on spousal concordance in depressive symptoms was different among husbands and wives. This study demonstrated both spousal support and spousal network aspects of spousal relationships. Depression concordance was stronger for couples with more negative marital relationship. A supportive marital relationship was associated with less concordance between spouses' depressive symptoms for wives but not for husbands. Spousal network overlap was associated with less depression concordance for husbands; however, for wives, spousal network overlap was directly associated with more depressive symptoms and did not mediate the association with depression concordance. Our findings suggest that approaches to supporting older adults dealing with mental health disorders may involve support at both the individual and couple levels. Gender-specific strategies could also be devised to improve the mental well-being of the older population.

Social connectedness and hair cortisol in community-dwelling older adults

PurposeHair cortisol is emerging as a reliable biomarker for measuring retrospective stress hormone levels. Given that social connectedness can buffer psychobiological stress reactivity, increasing attention is being paid to the specific types of social networks associated with the stress response. This study investigated the role played by two components of social life, emotional closeness and network size, to probe which aspects of social networks were related to stress measures. MethodsThe scalp hair cortisol level was used to assess the cumulative cortisol production in 179 community-dwelling older adults, in the Korean Social Life, Health, and Aging Project (KSHAP). Multivariate regression approach was used to examine the link between the stress measures (cortisol and perceived stress scale) and social relationships (social network size and emotional closeness). ResultsEmotional closeness (the average level of what one feels about one’s relationship) was significantly associated with decreased levels of hair cortisol, whereas no such relationship was found with the network size. ConclusionsThe current findings underscore the role of emotional support on reducing cumulative cortisol, thus providing potential resilience mechanisms for the psychobiological stress response.

Social Activities and Health-Related Quality of Life in Rural Older Adults in South Korea: A 4-Year Longitudinal Analysis.

During later life, inadequate social interactions may be associated with worse quality of life in older adults. Rural older adults are prone to developing unhealthy lifestyles related to social activities, which can lead to a poorer quality of life than that enjoyed by older adults living in urban areas. This study aimed to describe longitudinal changes in social activity participation and health-related quality of life among rural older adults, exploring potential associations with changes to in-person social activity over four years. We used prospective community-based cohort data from the Korean Social Life, Health, and Aging Project (KSHAP) collected between December 2011 and January 2016. The sample included 525 older adults who completed the measure of health-related quality of life. Our results showed a significant change in health-related quality of life according to changes in participation in meeting with friends. Even though an individual’s participation in other social activities did not show significant differences in health-related quality of life, our findings imply that in-person social activities may be an important resource to encourage participation in physical activities and to develop other positive outcomes, such as a sense of belonging or satisfaction with later life, among rural older adults.

Association between estimated glomerular filtration rate (eGFR) and asymmetric dimethylarginine (ADMA) concentrations among the elderly in a rural community: a cross-sectional study

BackgroundReduced glomerular filtration rate and increased asymmetric dimethylarginine (ADMA) are prevalent in elderly people. However, most of the studies that have examined the association between the two conditions were performed in patients with renal dysfunction, but not in the general elderly population. Thus, we investigated an association between estimated glomerular filtration rate (eGFR) and ADMA concentration among community-dwelling older Koreans.MethodsA cross-sectional study was conducted on 269 men and 382 women (mean age, 71.6 years) enrolled in the Korean Social Life, Health, and Aging Project (KSHAP), a population-based cohort study of health determinants in elderly Koreans. We calculated eGFR using chronic kidney disease- Epidemiology Collaboration Group (CKD-EPI) equation. ADMA concentration was measured by an enzyme-linked immunosorbent assay. The association between eGFR and ADMA concentrations was analyzed by multiple linear regression models.ResultsThe mean ADMA was significantly higher in people with eGFR< 60 mL/min/1.73m2 (0.691 μmol/L) than in those with eGFR≥60 mL/min/1.73m2 (0.667 μmol/L, p = 0.013). The negative correlations between eGFR level and ADMA concentrations were significant in men and women after adjusted age. After adjusting for potential confounders which were sex, age, body surface, blood pressure, total and HDL cholesterol, diabetes, smoking, and drinking, eGFR levels were inversely associated with ADMA concentrations both in men (β = − 0.0015, p = 0.005) and women (β = − 0.001, p = 0.039).ConclusionOur findings suggest that an inverse association exists between eGFR and ADMA concentrations among the Korean elderly in a rural community.

Associations of systemic inflammation with frontotemporal functional network connectivity and out-degree social-network size in community-dwelling older adults

Increasing evidence suggests that systemic inflammation adversely affects social experiences and behaviors of older adults by changing the functional state of the brain. In this study, we investigated the relationships among systemic inflammation, functional network connectivity (FNC) of the whole brain, and social-network size using complete social-network data of older adults residing in a Korean village. Sixty-one participants were recruited from the Korean Social Life, Health, and Aging Project (KSHAP). Participants underwent a resting-state functional magnetic resonance imaging scan. High sensitivity C-reactive protein (hs-CRP) levels were measured as an inflammation marker. In-degree and out-degree network sizes were calculated based on the total number of intimate social relationships per participant. We demonstrated that hs-CRP levels were associated with decreased frontotemporal FNC. Stronger frontotemporal FNC was significantly correlated with a larger out-degree network size, suggesting that impaired frontotemporal communication in older adults decreases perceived social connectedness with other people. An exploratory mediation analysis supported the observation that increased systemic inflammation contributes to reduced out-degree social-network size among older adults by changing frontotemporal FNC. The present findings provide meaningful insight into the complex relationship between systemic inflammation and social quality of life.

Is the Relationship between Depression and C Reactive Protein Level Moderated by Social Support in Elderly?-Korean Social Life, Health, and Aging Project (KSHAP)

ObjectiveTo investigate the buffering effects of social support as an effects modifier in the association between depression and inflammation in the elderly.MethodsWe analyzed the Korean Social Life, Health, and Aging Project (KSHAP) for questionnaire, clinical, and laboratory data of 530 older adults living in a rural community. Multivariate regression models were used to investigate the association between depressive symptoms and C-reactive protein level (CRP), a marker of inflammation, at varying levels of social support.ResultsSocial support affected the association between depressive symptoms and CRP level in both sexes. However, the direction of effects modification was different for men and women. In men, a higher CRP level was significantly associated with depressive symptoms only among those with lower support from a spouse or family members. By contrast, in women, the association was significant only among subgroups with higher spousal or family support. Social support from neighbors or friends did not affect the depression-inflammation relationship in men but modestly affected the relationship in women.ConclusionOur findings suggest that social support may have a buffering effect in the relationship between depression and inflammation in elderly Koreans. But the influence of social support may run in different directions for men and women.

Association between vitamin D status and asymmetric dimethylarginine (ADMA) concentration in the Korean elderly population

ObjectivesVitamin D deficiency has been reported to be associated with the risk of cardiovascular disease. We investigated the relationship between vitamin D status and asymmetric dimethylarginine (ADMA) concentration, a marker of endothelial dysfunction, in the Korean elderly population. Study designA cross-sectional study was conducted on 269 men and 382 women (mean age, 71.6 years) enrolled in the Korean Social Life, Health, and Aging Project (KSHAP), a population-based longitudinal study of health determinants in elderly Koreans. We stratified patients by vitamin D status into three groups according to serum 25-hydroxyvitamin D [25(OH)D] level: sufficient (≥30ng/mL, n=25), insufficient (10-<30ng/mL, n=516), and deficient (<10ng/mL, n=110). To measure endothelial dysfunction, ADMA concentration was assayed by high-performance liquid chromatography. The association between 25(OH)D status and ADMA concentration was analyzed by multiple linear regression models. ResultsThe mean ADMA concentration was significantly higher in the insufficient 25(OH)D group (0.665μmol/L, p=0.001) and the deficient 25(OH)D group (0.734μmol/L, p<0.001) compared with the sufficient 25(OH)D group (0.589μmol/L). Even after adjusting for sex, age, body mass index, blood pressure, diabetes mellitus, total and HDL cholesterol, estimated glomerular filtration rate (eGFR), smoking status, and drinking status, ADMA concentrations were higher in the insufficient group (β=0.0742μmol/L, p=0.001) and the deficient group (β=0.1417μmol/L, p<0.001) compared than in the sufficient group. In a sex-stratified analysis, 25(OH)D deficiency was associated with higher ADMA levels in both women (p<0.001) and men (p=0.007), while 25(OH)D deficiency was associated with higher ADMA levels in women (p<0.001) but not in men (p=0.631). ConclusionOur findings suggest that low serum 25(OH)D level may be associated with endothelial dysfunction in elderly Korean people.

The Effect of Social Support and Conflict in Different Types of Relationships on Depression and Suicidal Ideation among the Young-Old and the Old-Old

본 연구는 농촌지역 노인을 대상으로 관계 유형별 사회적 지지와 갈등이 우울과 자살사고에 미치는 영향을 알아보고, 이러한 영향이 노년기 전기와 후기에 다르게 나타나는지 탐색하는 것을 목적으로 한다. 본 연구의 대상자는 “한국인의 사회적 삶, 건강한 노화에 대한 조사(Korean Social Life, Health and Aging Project, KSHAP)”의 1차 조사에 참여한 만 60세 이상의 정상노인이다. 연구 대상자를 60-74세의 전기노년기 집단과 75세 이상의 후기노년기 집단으로 구분하였다. 각 집단에서 관계유형별(배우자, 가족 및 친척, 친구 및 이웃)로 세분화한사회적 지지와 사회적 갈등이 우울에 미치는 영향을 다중회귀분석을 사용하여 분석하였다. 또한 사회적 지지와 갈등이 노인 우울과 관련성이 큰 자살사고에 미치는 영향을 로지스틱회귀분석을 사용하여 분석하였다. 그 결과, 전기 노년기 우울에는 배우자, 친구 및 이웃과의 관계의 질이 특히 중요하며, 배우자, 친구 및 이웃으로부터의 지지가 적고 갈등이 많을수록 더 우울하였다. 반면, 후기 노년기 우울에는 어떠한 관계 유형에서도 사회적 지지와 갈등의 영향이 유의하지 않았다. 한편 주관적 건강상태와 우울 수준을 통제했을 때, 가족과 친척의 지지가 많을수록 자살사고를 보고하는 노인들이 적었다. 마지막으로, 본 연구결과가 추후 연구방향 및 임상적 개입에 갖는 함의와 본 연구의제한점에 대해 논의하였다.

Sex-specific effects of social networks on the prevalence, awareness, and control of hypertension among older Korean adults.

BackgroundHypertension is a common chronic disease among older adults, and is associated with medical complications and mortality. This study aimed to examine the effects of social network characteristics on the prevalence, awareness, and control of hypertension among older adults.MethodsThe Korean Social Life, Health, and Aging Project (KSHAP) interviewed 814 ≥ 60-year-old residents and their spouses from a rural township between December 2011 and March 2012 (response rate: 95%). We evaluated the data from 595 participants. Multivariate logistic regression models were used to assess the effects of network characteristics on hypertension.ResultsWe observed strong sex-specific network effects on the prevalence, awareness, and control of hypertension. Among older women, network density was associated with hypertension awareness [odds ratio (OR): 2.63, 95% confidence interval (CI): 1.03–5.37] and control (OR: 1.72; 95% CI: 0.94–3.13). Among older men, large networks were associated with a lower prevalence of hypertension (OR: 0.75; 95% CI: 0.58–0.96). Compared to older women, older men with coarse networks exhibited better hypertension awareness (OR: 0.37; 95% CI: 0.14–0.95) and control (OR: 0.42; 95% CI: 0.19–0.91). Network size interacted with density for hypertension control (P = 0.051), with controlled hypertension being associated with large and course networks.ConclusionsA large network was associated with a lower risk for hypertension, and a coarse network was associated with hypertension awareness and control among older men. Older women with dense networks were most likely to exhibit hypertension awareness and control.

The korean social life, health and aging project-health examination cohort.

The Korean Social Life, Health, and Aging Project (KSHAP) is a population-based longitudinal study of health determinants among elderly Koreans. The target population of the KSHAP are people aged 60 years or older and their spouses living in a rural community of Korea. A complete enumeration survey was conducted in the first wave of the KSHAP on 94.7% (814 of 860) of the target population between December 2011 and July 2012. The KSHAP-Health Examination (KSHAP-HE) cohort consists of 698 people who completed additional health examinations at a public health center (n=533) or at their home (n=165). Face-to-face questionnaires were used to interview participants on their demographics, social network characteristics, medical history, health behaviors, cognitive function, and depression symptoms. Health center examinations included anthropometric measures, body impedance analysis, resting blood pressure measurement, radial artery tonometry, bone densitometry, the timed up-and-go test, and fasting blood analysis. However, only anthropometric measures, blood pressure measurement, and non-fasting blood analysis were available for home health examinations. Collaboration is encouraged and access to the KSHAP baseline data will be available via the website of the Korean Social Science Data Archive (http://www.kossda.or.kr).