Does social support differentially affect sleep in older adults with versus without insomnia?

Objective: Insomnia is a significant public health problem, particularly among older adults. We examined social support as a potential protective factor for sleep among older adults (60 years and older) with insomnia (n=79) and age- and sex-matched controls without insomnia (n=40). Methods: Perceived social support, sleep quality, daytime sleepiness, and napping behavior were assessed via questionnaires or daily diaries. In addition, wrist actigraphy provided a behavioral measure of sleep continuity parameters, including sleep latency (SL), wakefulness after sleep onset (WASO), and total sleep time (TST). Analysis of covariance for continuous outcomes or ordinal logistic regression for categorical outcomes were used to examine the relationship between social support and sleep-wake characteristics and the degree to which observed relationships differed among older adults with insomnia versus non-insomnia controls. Covariates included demographic characteristics, depressive sytnptoms, and the number of medical comorbidities. Results: The insomnia group had poorer subjective sleep quality, longer diary-assessed SL and shorter TST as compared to the control group. Higher social support was associated with lesser actigraphy-assessed WASO in both individuals with insomnia and controls. There was a significant patient group by social support interaction for diary-assessed SL, such that higher levels of social support were most associated with shorter sleep latencies in those with insomnia. There were no significant main effects of social support or social support by patient group interactions for subjective sleep quality, daytime sleepiness, napping behavior, or TST (diary or actigraphy assessed). Conclusion: These findings extend he literature documenting the health benefits of social support, and suggest that social support may similarly influence sleep in individuals with insomnia as well as non-insomnia controls. (C) 2010 Elsevier Inc. All rights reserved.