44. A History of Fracture is Associated with Chronic Whole Body Pain: Findings from UK Biobank

Abstract

Background: Pain all over the body is a key component of chronic widespread pain (CWP), a common condition which often results in high levels of disability. Underlying mechanisms are complex and may involve neural systems, the hypothalamic-pituitary-adrenal (HPA) axis, and psychological indices. Although there is some evidence that CWP may follow a traumatic event, there are scant data relating to the occurrence of CWP following a history of a bone fracture. Whilst the case definition of CWP requires use of pain mannequins, which may not be feasible in a large population cohort, the presence of chronic pain all over the body, readily obtainable by self-report, affords a practical surrogate marker. The aim of this study was therefore to explore the association between presence of pain all over the body and previous fracture in a large population-based cohort, UK Biobank. Method(s): UK Biobank is a large prospective cohort comprising 500,000 men and women aged 40-69 years. Baseline assessment included detailed information covering health, medications, lifestyle, diet, physical activity and body build. Specifically data relating to past fracture over the last 5 years, and the presence of pain all over the body>3months duration (PATB) were obtained. Poisson regression models with robust CIs were used to explore associations between presence of PATB and any fracture in the past 5 years, with adjustment for confounding factors, initially in the whole cohort and then separately for males and females. Results are presented as risk ratio (RR). Result(s): The mean (S.D.) age of participants was 57 (8.1) years and just over half were female (54%). The overall prevalence of PATB was 1.4%, as it was in those without previous facture, while it was somewhat higher among those with a previous fracture (2.1%). A previous fracture was associated with a 51% increased the risk of PATB (RR: 1.51; 95% CI: 1.41, 1.62). The association was somewhat attenuated after adjustment for demographic characteristics (sex, age, BMI), lifestyle (alcohol consumption, smoking, physical activity) and socio-economic factors (deprivation index, household income) (RR: 1.37; 95% CI: 1.28, 1.47) and after further adjustments for psychological risk factors (RR: 1.20; 95% CI: 1.05, 1.37), but in each case the association remained statistically significant. After stratification by sex, relationships between previous fracture and PATB appeared somewhat stronger in men than in women (fully adjusted RR men: 1.32; 95% CI: 1.05, 1.66; and RR women: 1.15; 95% CI: 0.98, 1.35). Conclusion(s): In this large population-based cohort, previous fracture was associated with an increased risk of chronic pain all over the body, particularly in men, even after adjustment for a wide range of confounding factors. These results require replication in other settings, but raise the possibility that fracture may predispose to chronic widespread pain, perhaps through perturbation of the HPA axis, or psychological stressors.