Social isolation, loneliness, and inflammation: A multi-cohort investigation in early and mid-adulthood

Year: 2023

Type: article

Abstract: Social isolation and loneliness have been associated with poor health and increased risk for mortality, and inflammation might explain this link. We used data from the Danish TRIAGE Study of acutely admitted medical patients (N = 6,144, mean age 60 years), and from two population-representative birth cohorts: the New Zealand Dunedin Longitudinal Study (N = 881, age 45) and the UK Environmental Risk (E-Risk) Longitudinal Twin Study (N = 1448, age 18), to investigate associations of social isolation with three markers of systemic inflammation: C-reactive protein (CRP), interleukin-6 (IL-6), and a newer inflammation marker, soluble urokinase plasminogen activator receptor (suPAR), which is thought to index systemic chronic inflammation. In the TRIAGE Study, socially isolated patients (those living alone) had significantly higher median levels of suPAR (but not CRP or IL-6) compared with patients not living by themselves. Social isolation prospectively measured in childhood was longitudinally associated with higher CRP, IL-6, and suPAR levels in adulthood (at age 45 in the Dunedin Study and age 18 in the E-Risk Study), but only suPAR remained associated after controlling for covariates. Dunedin Study participants who reported loneliness at age 38 or age 45 had elevated suPAR at age 45. In contrast, E-Risk Study participants reporting loneliness at age 18 did not show any elevated markers of inflammation. In conclusion, social isolation was robustly associated with increased inflammation in adulthood, both in medical patients and in the general population. It was associated in particular with systemic chronic inflammation, evident from the consistently stronger associations with suPAR than other inflammation biomarkers.

Source: Brain Behavior and Immunity

DOI: 10.1016/j.bbi.2023.11.022

Authors: Timothy Matthews, Line Jee Hartmann Rasmussen, Antony Ambler, Andrea Danese, Jesper Eugen-Olsen, Daisy Fancourt, Helen L. Fisher, Kasper Karmark Iversen, Martin Schultz, Karen Sugden, Benjamin Williams, Avshalom Caspi, Terrie E. Moffitt

Institutions: University of Greenwich, Duke University, Amager Hospital, Hvidovre Hospital, Copenhagen University Hospital, King's College London, South London and Maudsley NHS Foundation Trust, University College London, University of Copenhagen, Herlev Hospital, Gentofte Hospital

Language: English

Topic: Health disparities and outcomes

Subfield: Health

Field: Social Sciences

Domain: Social Sciences

SDG: Good health and well-being

Open Access status: hybrid

Estimated APC paid: $4,480

Funders: University of Otago, South London and Maudsley NHS Foundation Trust, Wellcome Trust, National Institute for Health and Care Research, Department of Health and Social Care, King's College London, Lundbeckfonden, Jacobs Foundation, H. Lundbeck A/S, Medical Research Council, Economic and Social Research Council, National Institute on Aging, National Institute of Child Health and Human Development, Eunice Kennedy Shriver National Institute of Child Health and Human Development

OpenAlex ID: W4388849789