Social asymmetry and physical health outcomes: results from the Irish longitudinal study on ageing

Abstract

Background: We previously showed that Social Asymmetry (SA), a novel metric describing susceptibility to experiencing loneliness relative to social isolation status, is associated with cognitive outcomes. Here we investigate its association with physical health outcomes. Methods: Design: Longitudinal cohort study. Participants: 8163 adults over 50, representative of older Irish adults. Measures: SA calculated from UCLA Loneliness scale and Social Network Index. Counts of a) physical impairments, b) impairments in activities of daily living (ADL), and c) impairments in instrumental activities of daily living (IADL) as outcomes. Covariates: age, gender, cognitive status (MMSE), depressive symptomatology (CESD), a count of cardiovascular conditions and a count of chronic illnesses. Analysis: Hierarchical regression analyses were conducted on all three outcomes both cross-sectionally, and at follow-up at Wave 2, two years later, as residualised change scores. Findings: Of the participants, 16% were classified as Discordant: Susceptible to Loneliness; 31.5% as Concordantly (high) Lonely and Isolated; 36% as Concordantly (low) Lonely and Isolated, and 16.5% as Discordant: Robust to loneliness. Discordant: Susceptible to Loneliness was the category cross-sectionally associated with highest levels of physical (β = -1.66***), ADL (β = -0.9*), and IADL impairments (β = -1.9***). Additionally this category was associated with higher levels of increase in physical (β = -0.08**), ADL (β = -0.02***) and IADL (β = -1.7***) impairments. Conclusion: Individuals most at risk of increases in physical and functional impairment cross-sectionally and over time are those who have the largest discrepancy between (high) levels of loneliness and (low) levels of isolation.