Weight discrimination partially mediates the longitudinal relationship between Body Mass Index and pain

Abstract

Pain is common among individuals with high Body Mass Index (BMI). This study investigated weight discrimination as a mediator of the longitudinal relationship between BMI and the presence of moderate/severe pain among adults from the English Longitudinal Study of Ageing (ELSA) cohort. ELSA is a longitudinal study of middle-aged and older adults living in England. Data were taken from three consecutive waves. Demographics, BMI, and self-reported pain were collected at wave 4 (2008–2009), perceived weight discrimination at wave 5 (2010–2011,) and pain (no/mild vs moderate/severe) at wave 6 (2012–2013). Generalized linear models estimated the association of BMI at wave 4 (assessed continuously and dichotomized to obesity status BMI ≥30) with pain at wave 6, and weight discrimination at wave 5 as a mediator of this relationship. Models were adjusted for demographics and baseline pain. Complete data were available for n=5362 individuals. Continuous BMI was associated with future moderate/severe pain (b=1.05 SE=0.01, p<.01) and weight discrimination partially mediated this effect (b=1.00 SE=0.002, p=.05). Obesity status was also significant (b=1.43 SE=0.11, p<.01) but weight discrimination did not mediate the relationship (p=.13). Post hoc analyses were conducted among individuals with no/mild pain at baseline (n=3979.) BMI and obesity status were both associated with pain and weight discrimination mediated both pathways (ps<.05.) Weight discrimination partially mediated the relationship between BMI and future moderate/severe pain, especially among individuals with no/mild pain initially. Weight discrimination may be an overlooked contributor to the transition to more severe pain among individuals of higher body weight.

Perspective

Weight discrimination may be an overlooked contributor to pain among individuals of higher body weight, particularly transition from lower to higher impact states. Post hoc analyses indicate the effect may be specific, as other forms of discrimination did not mediate the relationship.