Is poor self-rated sleep quality associated with elevated systemic inflammation in healthy older adults?

Objective Examine subjective sleep quality and inflammation among healthy older adults participating in the Australian Research Council Longevity Intervention (ARCLI). Methods Data was taken from a sub-set of 232 participants aged between 60–70 years (M = 65.88 ± SD 4.08 years) who participated in the baseline assessment phase of the Australian Research Council Longevity Intervention (ARCLI) study. Subjective sleep was assessed via the Leeds Sleep Evaluation Questionnaire (LSEQ). Inflammatory markers (TNF-α, IL-1β, IL-6, IL-10, IL-2, IFN-γ, IL-4, hs-CRP) were derived from whole blood. Correlation and multiple regression analyses were used to examine associations between each of the four sleep outcome variables and inflammatory outcomes, examined as a group and following gender stratification. Results Difficulties getting to sleep were independently associated with higher IL-2 [F(1,156) = 4.62, adjusted = 0.02, p = 0.03] and IL-1β [F(1,141) = 8.52, adjusted = 0.05, p = 0.004] (whole group). Difficulties getting to sleep were associated with greater IL-1β [males: F(1,58) = 7.36, adjusted = 0.097 p = 0.009; females: F (1,81) = 4.25, = 0.038, p = 0.04], and negatively associated with hs-CRP (women) [F (1,129) = 4.71, = 0.028, p = 0.032]. Discussion Subjective sleep-onset difficulties are associated with systemic inflammation.