| dc.description.abstract | Background: Chronic back pain is a major health issue that affects one of five adults every year around the world. It is well established that insomnia symptoms are associated with increased risk of chronic back pain, but it remains uncertain whether combinations of selected lifestyle factors modify the adverse effect of insomnia symptoms.
Objective: To examine if a healthy lifestyle modifies the association between insomnia symptoms and the risk of chronic back pain and back-related disability.
Design, setting, and participants: A prospective cohort study using longitudinal data from the Trøndelag Health Study, Norway. Participants included a total of 9330 people who reported to be free from chronic musculoskeletal pain at baseline in HUNT3 (2006–2008). The follow-up period was ~11 years.
Exposures and statistical analysis: A modified Poisson regression was used to estimate adjusted risk ratios (RRs) with 95% confidence intervals (CI) between the joint effect of insomnia symptoms and healthy lifestyle on the risk of chronic back pain and back-related disability. Five lifestyle factors (leisure time physical activity, diet, body mass index, smoking, and alcohol consumption) were each allocated a score (0 = healthy, 1 = unhealthy) and further aggregated into a lifestyle score ranging from 0 (best) to 5 (worst).
Result: Overall, 426 incident cases of chronic back pain and 211 cases of back-related disability were reported during the follow-up period of ~11 years. Compared to people without insomnia symptoms and the best lifestyle score, a RR for chronic back pain was 1.28 (95% CI: 1.12-1.43) if they did not report insomnia symptoms and had the worst lifestyle score and a RR of 1.69 (95% CI: 1.40-2.04) if they reported insomnia symptoms and worst lifestyle score. Using the same reference group of people without insomnia symptoms and the best lifestyle score gave RRs for back-related disability of 1.57 (95% CI: 1.29-1.92) for those without insomnia symptoms and the worst lifestyle score; 2.75 (95% CI: 2.11-3.58) for those with insomnia symptoms and the worst lifestyle score. Although the CIs in the analyses of additive interaction were wide, they indicate weak additive interaction of insomnia symptoms and lifestyle on back-related disability.
Conclusion: These results suggest that a healthy lifestyle may modify some of the adverse effect of insomnia symptoms on the risk of back-related disability. | |