Prospective associations of social isolation and loneliness with poor sleep quality in older adults

Purpose
There is evidence for negative associations between social isolation and loneliness and sleep quality in older adults. However, it is unclear to what extent these two factors independently affect sleep quality. This study examined the simultaneous associations of social isolation and loneliness with sleep quality in a longitudinal study of older adults.
Methods
Data were analyzed from the Social Environment and Biomarkers of Aging Study in Taiwan collected in 2000 and 2006, involving a cohort of 639 participants (mean age = 66.14, SD 7.26). Poisson regression models were conducted to examine the association of social isolation and/or loneliness with sleep quality at follow-up after adjusting for multiple confounding variables.
Results
Univariate analysis showed that sleep quality was inversely associated with both social isolation and loneliness. After demographic, health, cognitive factors, and depressive symptoms were controlled in multivariable analysis, social isolation at the baseline still predicted poor sleep quality 6 years later (incident rate ratio, IRR 1.14; 95% CI 1.04–1.24; p < 0.01), while the association between loneliness and sleep quality was no longer significant (IRR 1.08; 95% CI 0.94–1.23; p = 0.27). The results were unchanged when participants who had poor sleep quality at the baseline were excluded from the analysis.
Conclusions
These findings confirm an adverse effect of social isolation on the sleep quality of older adults, but indicate that this effect is independent of loneliness. Social isolation and loneliness seem to have distinct pathways in affecting the sleep quality of older adults.