부산대학교 도서관

Chronic increases in pro-inflammatory cytokines in older adults, known as inflammaging, is an important risk factor for morbidity and mortality in the aging population. It has been suggested that circadian disruption may play a role in chronic inflammation, but there has been limited study that investigated the overall profile of 24-hour rest-activity rhythms in relation to inflammation using longitudinal data. In the Outcomes of Sleep Disorders in Older Men Study, we applied the extended cosine model to derive multiple rest-activity rhythm characteristics using multi-day actigraphy, and examined their associations with six inflammatory markers (i.e., CRP, IL-6, TNF-α, TNF-α-sRII, IL-1 β, IFN-γ) measured from fasting blood. We assessed both the cross-sectional association between rest-activity rhythms and inflammatory markers measured at baseline, and the prospective association between baseline rest-activity rhythms and changes in in inflammatory markers over 3.5 years of follow up. We found that multiple rest-activity characteristics, including lower amplitude and relative amplitude, and decreased overall rhythmicity, were associated with higher levels of CRP, IL-6, TNF-α, and TNF-α-sRII, but not IL-1β and IFN-γ at baseline. Moreover, the lowest quartile of these three rest-activity characteristics was associated with an approximately two-fold increase in the odds of having elevated inflammation (i.e. having three or more markers in the highest quartile) at baseline. However, we found little evidence supporting a relationship between rest-activity rhythm characteristics and changes in inflammatory markers. Future studies should clarify the dynamic relationship between rest-activity rhythms and inflammation in different populations, and evaluate the effects of improving rest-activity profiles on inflammation and related disease outcomes.