The Relationship between Environmental Racism and Mechanisms of the Native American Pain Disparity: Preliminary Results from the Oklahoma Study of Native American Pain Risk (OK-SNAP)

Abstract

Native Americans (NAs) experience higher rates of chronic pain than the general U.S. population and we have recently shown that pain-free NAs are ∼3x more likely than non-Hispanic Whites (NHWs) to prospectively develop chronic pain. Moreover, this pain disparity is partially mediated by stress-related factors (discrimination, psychological stress, cardiometabolic allostatic load) and a unique NA pain risk phenotype we call "silent" spinal sensitization (sensitization of the nociceptive flexion reflex [NFR] during a conditioned pain modulation [CPM] task without sensitization of pain experience). NAs have endured and continue to endure structural racism and discrimination (SRD) due to colonization (eg, genocide, cultural oppression), including forced removal from Native lands and policies that lead to desecration of the natural environment. Most NA traditional beliefs include a sacred connection to nature; thus, environmental SRD may be particularly relevant for this population. The present study examined the impact of environmental SRD (racialized distribution of environmental pollutions/hazards) on mechanisms of the NA pain disparity in 282 healthy NAs and NHWs. CPM was used to assess individual differences in modulation of pain perception and the NFR. The Environmental Protection Agency's 11 publicly-available environmental (in)justice variables at the Oklahoma census block level were used to form a latent variable that was linked to participants via geocoding. This latent variable: a) explained 87% of the variance in the original 11 injustice variables, b) correlated with the proportion of NAs within a census region suggesting it assesses racialized NA exposure to pollution, and c) formed an indirect (mediated) pathway with NFR sensitization, but not pain sensitization, via stress-related mechanisms. This indirect path was significant in NAs, but not NHWs. These preliminary findings suggest that SRD may contribute to pain inequities in NAs. This research was supported by the National Institute on Minority Health and Health Disparities of the National Institutes of Health under Award Number R01MD007807, and by the University of Tulsa Office of Research and Sponsored Programs. The content is solely the responsibility of the authors and does not necessarily represent the official views of the National Institutes of Health or the University of Tulsa.