Long-Term Changes in Musculoskeletal Pain Sites in the General Population: The HUNT Study

Abstract

In a Norwegian prospective population-based cohort study, we examined whether the number of chronic musculoskeletal pain sites changed over an 11-year period, and if the number of pain sites at follow-up was associated with health-related and lifestyle factors at baseline. The study included data on 78,973 adults participating in the Nord-Trøndelag Health Study (HUNT) in 1995 to 1997 (HUNT2) and 2006 to 2008 (HUNT3). On the basis of 3 categories of baseline pain sites, associations between baseline health-related, lifestyle, and demographic factors and number of pain sites at follow-up were analyzed with linear regression models adjusted for age, sex, marital status, physical activity, education, and other chronic diseases. We also estimated within-subject associations. Regardless of pain extent at baseline, anxiety and/or depression, sleeping problems, smoking, and obesity were positively associated with number of pain sites at follow-up, whereas education and physical activity were inversely associated with number of pain sites. The within-subject analyses showed largely similar associations for the health-related factors, whereas associations of lifestyle factors were attenuated. The mean number of pain sites remained unchanged between the 2 surveys. Overall, our study revealed prospective associations between several factors and pain sites 11 years later, regardless of the number of pain sites at baseline.

Perspective: This prospective study examined the association between development of pain and risk factors in the general population, on the basis of 3 categories of baseline pain sites. It also examined how these factors influence possible long-term changes in pain within individuals. We showed that having no or few baseline pain sites may not differ in its risk factors compared with having multiple pain sites. This article provides an important contribution to the ongoing debate regarding the association between lifestyle, demographic, and psychosocial risk factors, versus the course of multisite chronic pain. Additionally, we provide discussion on potential directions for clinical relevance and further research.

Keywords: Chronic musculoskeletal pain; general population; pain; prospective epidemiologic study; risk factors.