Long-term changes in musculoskeletal pain sites in the general population: the HUNT study

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 1995–1997 (HUNT2) and 2006–2008 (HUNT3). Based on three categories of baseline pain sites, associations between baseline health-related, lifestyle, and demographic factors and number of pain sites at follow-up were analysed 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, while 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 two 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