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 with OA did not have higher risk of elevated CRP or IL-6 levels. However, indirect associations of OA through sleep health were found. OA was associated with poorer sleep health, which was further associated with 16% higher odds of elevated CRP (P < 0.001) and 12% higher odds of elevated IL-6 (P < 0.01) levels after controlling for OA. Older men with RA had higher odds of elevated CRP and IL-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 with OA.

Stress is an established risk factor for negative health outcomes, and responses to everyday stress can interfere with health behaviors such as exercise and sleep. In accordance with the Science of Behavior Change (SOBC) program, we apply an experimental medicine approach to identifying stress response targets, developing stress response assays, intervening upon these targets, and testing intervention effectiveness. We evaluate an ecologically valid, within-person approach to measuring the deleterious effects of everyday stress on physical activity and sleep patterns, examining multiple stress response components (i.e., stress reactivity, stress recovery, and stress pile-up) as indexed by two key response indicators (negative affect and perseverative cognition). Our everyday stress response assay thus measures multiple malleable stress response targets that putatively shape daily health behaviors (physical activity and sleep). We hypothesize that larger reactivity, incomplete recovery, and more frequent stress responses (pile-up) will negatively impact health behavior enactment in daily life. We will identify stress-related reactivity, recovery, and response in the indicators using coordinated analyses across multiple naturalistic studies. These results are the basis for developing a new stress assay and replicating the initial findings in a new sample. This approach will advance our understanding of how specific aspects of everyday stress responses influence health behaviors, and can be used to develop and test an innovative ambulatory intervention for stress reduction in daily life to enhance health behaviors.