Loneliness and cognitive function in older adults: Longitudinal analysis in 15 countries.

This study aims to evaluate the directionality of the association between loneliness and cognitive performance in older adults, accounting for confounding factors. Data were from 55,662 adults aged ≥ 50 years who participated in Waves 5-8 of the Survey of Health, Ageing and Retirement in Europe (SHARE). Loneliness was assessed with the Three-Item Loneliness Scale (TILS) and with a one-item direct question. Cognitive performance was assessed with four measures: verbal fluency, numeracy, immediate recall, and delayed recall. Age, sex, geographical area, educational attainment, partnership status, depressive symptoms, and previous chronic diseases at baseline were used as covariates. We analyzed the associations with three-wave random intercept cross-lagged panel models (RI-CLPM) and conducted age-stratified analysis among those younger versus older than 65 years. Full information maximum likelihood estimators were used to handle missing values in Waves 6-8 in the main analyses. We also conducted additional sensitivity analyses stratified by retirement status (retired vs. not) at baseline. At the within-person level, loneliness and cognitive performance were not associated with each other among those aged 50-64 years in the main time-lagged analysis. Among those aged ≥ 65 years, loneliness was associated with lower cognitive performance in the next wave in all four cognitive domains. In addition, lower verbal fluency predicted greater loneliness in the next waves among this age group. Similar patterns were found independently of retirement status at baseline. These results suggest that loneliness is a psychosocial risk factor for cognitive decline among older adults (≥ 65 years). (PsycInfo Database Record (c) 2023 APA, all rights reserved).

Association of social isolation and loneliness with risk of incident hospital-treated infections: an analysis of data from the UK Biobank and Finnish Health and Social Support studies.

BACKGROUND: Although loneliness and social isolation have been linked to an increased risk of non-communicable diseases such as cardiovascular disease and dementia, their association with the risk of severe infection is uncertain. We aimed to examine the associations between loneliness and social isolation and the risk of hospital-treated infections using data from two independent cohort studies. METHODS: We assessed the association between loneliness and social isolation and incident hospital-treated infections using data for participants from the UK Biobank study aged 38-73 years at baseline and participants from the nationwide population-based Finnish Health and Social Support (HeSSup) study aged 20-54 years at baseline. For inclusion in the study, participants had to be linked to national health registries, have no history of hospital-treated infections at or before baseline, and have complete data on loneliness or social isolation. Participants with missing data on hospital-treated infections, loneliness, and social isolation were excluded from both cohorts. The outcome was defined as a hospital admission with a primary diagnosis of infection, ascertained via linkage to electronic health records. FINDINGS: After exclusion of 8·6 million participants for not responding or not providing appropriate consent, the UK Biobank cohort consisted of 456 905 participants (249 586 women and 207 319 men). 26 860 (6·2%) of 436 001 participants with available data were reported as being lonely and 40 428 (9·0%) of 448 114 participants with available data were socially isolated. During a median 8·9 years (IQR 8·0-9·6) of follow-up, 51 361 participants were admitted to hospital due to an infectious disease. After adjustment for age, sex, demographic and lifestyle factors, and morbidities, loneliness was associated with an increased risk of a hospital-treated infection (hazard ratio [HR] 1·12 [95% CI 1·07-1·16]), whereas social isolation was not (HR 1·01 [95% CI 0·97-1·04]). Of 64 797 individuals in the HeSSup cohort, 18 468 (11 367 women and 7101 men) were eligible for inclusion. 4466 (24·4%) of 18 296 were lonely and 1776 (9·7%) of 18 376 socially isolated. During a median follow-up of 10·0 years (IQR 10·0-10·1), 814 (4·4%) participants were admitted to hospital for an infectious disease. The HRs for the HeSSup study replicated those in the UK Biobank (multivariable-adjusted HR for loneliness 1·32 [95% CI 1·06-1·64]; 1·08 [0·87-1·35] for social isolation). INTERPRETATION: Loneliness might increase susceptibility to severe infections, although the magnitude of this effect appears modest and residual confounding cannot be excluded. Interventional studies are required before policy recommendations can advance. FUNDING: Academy of Finland, the UK Medical Research Council, and Wellcome Trust UK.