Nature, Nurture, or Both? Study of sex and gender and their effects on pain
Abstract
As a pain researcher, in order to have a better understanding of pain, we should adopt a multidimensional view, such as the biopsychosocial (BPS) model and consider physical, psychological, and social elements altogether. The studies in this dissertation are part of the bigger project of SYMBIOME in which the aim is to help to create and develop a prognostic clinical phenotype in people post musculoskeletal (MSK) trauma. Chapter 2 presents a Confirmatory Factor Analysis (CFA) in order to assess the structural validity of the first section of the new Gender Pain and Expectation Scale (GPES). Our analysis indicated a 3-factor structure “Relationship-oriented,” “Emotive” and “Goal-oriented”. Its construct validity was also assessed. The subsequent study, chapter 3, explores the roles of sex-at-birth, GPES subscales and their interactions in explaining the variability of Brief Pain Inventory (BPI) Severity and Interference scores. It showed no sex differences in scores of BPI Pain Severity and BPI Pain Interference. GPES Relationship-oriented had a significant association with BPI pain severity (r=0.20) while GPES Emotive had a significant correlation with BPI Interference (r=0.24). Also, hierarchical multivariate linear regression suggested that GPES Emotive could partially explain the variances in pain-related interference. Chapter 4 presents correlations between sex-at-birth, hormones (Progesterone, DHEA-S, Estradiol, and Testosterone), GPES subscales and BPI scores. Also, as our second goal of this chapter, potential pathways between these variables have been tested through structural equation modelling. It has been shown that GPES Relationship-oriented had a significant correlation with progesterone (r=-0.21) and DHEA-S (r=-0.33), and GPES Emotive had a significant correlation with the DHEA-S (r=-0.20). The GPES Goal-oriented had a significant association with estradiol (r=-0.20). Our findings suggest that gender-related interpersonal-expressive characteristics could have mediator roles in relationships between sex-at-birth and pain, and also between the hormones and BPI pain ratings.