Date Published: May 22, 2018
Publisher: Oxford University Press
Author(s): Catharine R Gale, Leo Westbury, Cyrus Cooper.
loneliness and social isolation have been associated with mortality and with functional decline in older people. We investigated whether loneliness or social isolation are associated with progression of frailty.
participants were 2,817 people aged ≥60 from the English Longitudinal Study of Ageing. Loneliness was assessed at Wave 2 using the Revised UCLA scale (short version). A social isolation score at Wave 2 was derived from data on living alone, frequency of contact with friends, family and children, and participation in social organisations. Frailty was assessed by the Fried phenotype of physical frailty at Waves 2 and 4, and by a frailty index at Waves 2–5.
high levels of loneliness were associated with an increased risk of becoming physically frail or pre-frail around 4 years later: relative risk ratios (95% CI), adjusted for age, sex, level of frailty and other potential confounding factors at baseline were 1.74 (1.29, 2.34) for pre-frailty, and 1.85 (1.14, 2.99) for frailty. High levels of loneliness were not associated with change in the frailty index—a broadly based measure of general condition—over a mean period of 6 years. In the sample as a whole, there was no association between social isolation and risk of becoming physically frail or pre-frail, but high social isolation was associated with increased risk of becoming physically frail in men. Social isolation was not associated with change in the frailty index.
older people who experience high levels of loneliness are at increased risk of becoming physically frail.
Social relationships are important for health . Most such research has focused on social isolation or loneliness. Social isolation is defined objectively using criteria such as having few contacts, little involvement in social activities and living alone. Loneliness is a subjective feeling of dissatisfaction with one’s social relationships. Both social isolation and loneliness have been linked with increased mortality [2–4], incident heart disease [5, 6] and functional decline [7, 8]. Social isolation and loneliness tend to be correlated, albeit weakly .
For a full description of the methodology, see Appendix 1. We provide a summary below.
Table 1 shows the baseline characteristics of the sample and their rank order correlation with social isolation and loneliness. Being more socially isolated or lonelier was associated with being older, less educated, less wealthy, having more depressive symptoms, more chronic physical disease, being a smoker, having more components of the phenotype of frailty and a higher frailty index score. Being female was associated with greater loneliness and with slightly greater social isolation, though the latter relationship was of borderline significance (P = 0.066). There was a modest correlation between social isolation and loneliness (rho = 0.237) that did not differ between the sexes (P = 0.184). Participants who were physically frailer at baseline tended to have a higher frailty index score (rho = 0.40).
Table 1.Baseline characteristics of the participants and their rank order correlations with social isolation and loneliness scores (n = 2,817)aCharacteristicMean (SD), median (IQR) or No. (%)Correlation with social isolationCorrelation with lonelinessAge (yrs), mean (SD)69.3 (6.9)0.105***0.096***Female, n (%)1,604 (56.9)0.0350.110***Household wealth (£), median (IQR)207,300 (114,000–358,500)−0.214***−0.194***Educational qualifications−0.128***−0.127*** No qualifications, n (%)967 (34.3)Social isolation, median (IQR)1 (0–2)–0.237***Loneliness, median (IQR)3 (3–5)0.254***–Depressive symptoms, median (IQR)0 (0–1)0.069***0.310***Current smoker, n (%)297 (10.5)0.117***0.070***Number of chronic physical illnesses, median (IQR)1 (0–2)0.086***0.161***No. of components of frailty phenotype present at baseline, median (IQR)a0 (0–1)0.108***0.231***Frailty index at baseline, median (IQR)0.146 (0.108–0.216)0.120***0.287***aDescriptive data on the Fried phenotype of frailty are based on 2,346 participants. ***P < 0.001, **P < 0.01, *P < 0.05 To our knowledge, there have been no prospective studies of loneliness as a risk factor for frailty. However, prospective findings linking high levels of loneliness with decline in gait speed  or mobility , and increased difficulties with activities of daily life , or upper extremity tasks  suggest that loneliness may increase the likelihood of sarcopenia, an age-related syndrome characterised by loss of skeletal muscle mass and strength . Sarcopenia is a major contributor to risk of functional decline and physical frailty . The aetiology of sarcopenia is multifactorial, involving comorbidity, inflammation, insulin resistance, changes in endocrine function, nutritional deficiencies and low physical activity . The latter may be one mechanism underlying the association between loneliness and progression of physical frailty. Lonely people are more likely to be inactive [25, 26], and such inactivity increases the risk of physical frailty [27, 28]. Another potential mechanism may be diet. More socially engaged older people tend to have a higher quality diet . Source: http://doi.org/10.1093/ageing/afx188