Subjective Sleep Quality and Trajectories of Interleukin-6 in Older Adults

We aimed to identify trajectories of inflammation in older adults at elevated risk for syndromal depression and anxiety and to determine whether baseline physical, cognitive, and psychosocial factors could distinguish 15-month longitudinal trajectories.

Older adults (N = 195, mean age (±SD) = 74.4 years (9.0) participating in three depression and anxiety prevention protocols completed a comprehensive battery of psychosocial assessments and provided blood samples for analysis of interleukin-6 (IL-6) every 3 months over a maximum of 15 months. Group-based trajectory modeling identified trajectories. Adjusted logistic regression examined associations between baseline factors and trajectory groups.

Two 15-month trajectories were identified: stable lower IL-6 levels (84%; mean (±SD) = 3.2 (2.1) pg/mL); and consistently higher IL-6 levels (16%; mean = 9.5 (7.4) pg/mL). Poor sleep quality predicted consistently higher levels of IL-6 (OR = 1.9, 95% CI = 1.03-3.55).

Poor sleep quality may represent a therapeutic target to reduce inflammation.