Many studies have shown associations between grey matter structural measures and chronic pain (recently reviewed in Kang et al. 2018, European Journal of Pain). These studies were done in small samples (N < 100). The 40,000-person UK Biobank sample with comprehensive sets of structural brain imaging measures and up to 33 different chronic pain conditions enables us to test whether these findings withstand a scalar increase in sample size. Here we will test the associations of 4 sets of brain structural measures with pain phenotypes. For brain measures, we will use: 1. grey matter volumes, 2. surface area measures, and two sets of cortical thickness measures, using 3. Destrieux and 4. Desikan-Killiany parcellations. For pain conditions, we will start with two highly prevalent and most studied in brain imaging: back pain and osteoarthritis. We will use multivariate linear regression models, including potential confounds and/or explanatory variables (such as age, sex, and BMI) and their indirect effects. We will report all pairwise associations (with and without confounds) and brain maps of regions most consistently associated across pain conditions.
