Arthritis, Sleep Health, and Systemic Inflammation in Older Men.

Objective To examine the associations of prevalent arthritis with systemic inflammation in older men and to test whether sleep health mediates the associations. Methods Cross-sectional data came from 2,562 community-dwelling older men (all were age 65 years or older; mean age 76 years) in the Osteoporotic Fractures in Men Study who participated in a sleep ancillary study in 2003-2005. Participants were classified as having osteoarthritis (OA) (24%) or rheumatoid arthritis (RA) (0.7%) based on self-reported diagnoses and medication use. We constructed a composite score of multidimensional sleep health (i.e., perceived sleep quality, sleepiness, frequency of daytime napping, wake after sleep onset, and sleep duration) measured by both self-report and actigraphy. We also created binary indicators of elevated inflammation using C-reactive protein (CRP) (>3 mg/liter) and interleukin-6 (IL-6) (>1.08 pg/ml) levels. Analyses controlled for age, diagnosed sleep disorders, body mass index, smoking status, relevant medication use, and comorbidities. Results Older men withOAdid not have higher risk of elevatedCRPorIL-6 levels. However, indirect associations ofOAthrough sleep health were found.OAwas associated with poorer sleep health, which was further associated with 16% higher odds of elevatedCRP(P< 0.001) and 12% higher odds of elevatedIL-6 (P< 0.01) levels after controlling forOA. Older men withRAhad higher odds of elevatedCRPandIL-6 levels, but the associations were not mediated by sleep health. Conclusion Findings suggest that promoting sleep health may help reduce the risk of systemic inflammation in older men withOA.