Psychosocial and cardiometabolic predictors of chronic pain onset in Native Americans: serial mediation analyses of 2-year prospective data from the Oklahoma Study of Native American Pain Risk

Cerebral peak alpha frequency: Associations with chronic pain onset and pain modulation

Chronic pain is highly prevalent in the U.S. and leads to myriad negative sequalae and suffering. One way to address chronic pain is to identify who is at risk and intervene prior to symptom onset. Research suggests resting peak alpha frequency (PAF), the speed of alpha oscillations at rest, is slower in healthy individuals with greater pain sensitivity and in chronic pain patients. Thus, slower PAF may denote chronic pain vulnerability. Other research has shown that individuals at higher risk of chronic pain exhibit disrupted pain modulation, i.e., less efficient pain inhibition and increased pain facilitation. Currently, the ability of PAF to predict chronic pain and its relation to pain modulation is under-researched. This investigation aimed to address this gap by characterizing associations between PAF, onset of chronic pain, and pain modulation. Using archival data from three independent studies, this investigation assessed whether slower PAF is associated with prospectively-determined chronic pain onset, decreased pain inhibition (i.e., impaired conditioned pain modulation, impaired erotica-induced pain inhibition), and increased pain facilitation (i.e., increased temporal summation of pain, augmented mutilation-induced pain facilitation). Results show that slower PAF was associated with greater facilitation of spinal (i.e., nociceptive flexion reflex) and supraspinal (i.e., N2 potential) nociception in response to unpleasant pictures (i.e., human injury images). This suggests that slower PAF is associated with threat-enhanced spinal and supraspinal nociception and may be relevant for chronic pain conditions with disrupted threat systems. Slower PAF was not associated with any other pain outcome, including prospectively determined chronic pain onset. However, chronic pain onset could only be assessed in one study with a mixed eyes open/eyes closed recording, limiting the significance of this finding.

Using intensive longitudinal assessment to study mechanisms of the Native American pain inequity among persons experiencing depression and/or anxiety: The role of interpersonal discrimination and stress

Native Americans (NA) experience higher rates of chronic pain than other U.S. racial/ethnic groups. Our research has indicated discrimination and stress play a role in chronic pain onset. However, chronic pain research has mostly relied on retrospective reports that may be impacted by recall bias. The current study was a secondary analysis of data from 208 NA, 206 Black, 202 Latinx, and 206 non-Hispanic White (NHW) participants from an efficacy trial of a mobile health intervention for depression and anxiety. Participants were prompted to complete 6 months of twice daily ecological momentary assessments (EMAs) that included stress and pain. Discrimination was assessed at baseline. Pain EMAs were used to reduce recall bias and estimate chronic pain prevalence. Dynamic structural equation modeling assessed the impact of race/ethnicity and discrimination on stress-pain relationships, as well as pain and stress dynamics. To assess chronic pain (pain ≥3-months), participants had to complete ≥3-months of consecutive EMAs, leaving 578 participants available for primary analyses (there were no racial/ethnic differences in EMA completion). Results showed NAs had the highest rate of chronic pain that was statistically significantly higher than NHW and Black participants. Controlling discrimination eliminated the NA-NHW, but not the NA-Black, pain inequity. Moreover, a reciprocal stress-pain relationship was found and was stronger in NAs than other groups. Discrimination did not exacerbate stress-pain relationships but was associated with higher rates of chronic pain and greater pain fluctuations, regardless of race/ethnicity. These findings indicate that targeting stress and discrimination could help reduce the NA pain inequity. PERSPECTIVE: Native Americans experienced a self-reinforcing stress-pain cycle in which stress predicted future pain and pain predicted future stress. This cycle was stronger than Black, Latinx, and non-Hispanic White groups. Discrimination was associated with chronic pain but not stronger stress-pain relationships. These findings have implications for treatment.

Mechanisms of the Native American pain inequity: predicting chronic pain onset prospectively at 5 years in the Oklahoma Study of Native American Pain Risk

ABSTRACT

A pain inequity exists for Native Americans (NAs), but the mechanisms are poorly understood. The Oklahoma Study of Native American Pain Risk (OK-SNAP) addressed this issue and recruited healthy, pain-free NAs and non-Hispanic Whites (NHWs) to attend 2 laboratory visits and assessed mechanisms consistent with the biopsychosocial model of pain: demographics, physical variables, psychosocial factors, and nociceptive/pain phenotypes. Then participants were surveyed every 6 months to assess for chronic pain onset. Results at the 2-year follow-up found that NAs were ∼3x more likely than NHWs to develop chronic pain. Moreover, psychosocial factors (discrimination, stress, pain-related anxiety), cardiometabolic load (higher body mass index and blood pressure, lower heart rate variability), and impaired inhibition of spinal nociception partly mediated the pain inequity. The present study examined mechanisms of chronic pain at the 5-year follow-up for OK-SNAP. Results found that the NA pain inequity worsened-NAs were 4x more likely to develop chronic pain (OR = 4.025; CI = 1.966, 8.239), even after controlling for baseline age, sex assigned at birth, income, and education. Moreover, serial mediation models replicated paths from the 2-year follow-up that linked psychosocial variables, cardiometabolic load, and impaired inhibition of spinal nociception to chronic pain onset. Further, 2 new significant paths were observed. One linked discrimination, stress, sleep problems, and facilitated pain perception to increased pain risk. The other linked discrimination with higher spinal nociceptive threshold and pain risk. These results provide further evidence for a NA pain inequity and identify multiple psychosocial, cardiometabolic, and pronociceptive targets for primary interventions.

Reporting and incorporation of social risks in low back pain and exercise studies: A scoping review

BACKGROUND

Exercise is a common intervention for low back pain, but its effect sizes are small to modest. Social risk factors significantly influence health outcomes, yet their consideration in randomized controlled trials on exercise for low back pain is often neglected. Determining their relationship to outcomes may provide better insight into exercise effectiveness.

OBJECTIVES

To assess the reporting of social risk factors (SRFs) in randomized controlled trials (RCTs) of exercise interventions for low back pain (LBP) in adults and explore associations between SRFs and outcomes.

DESIGN

Scoping Review.

METHODS

The databases MEDLINE, CINAHL and Cochrane were searched for studies published between January 2014 to March 2025. RCTs were included if exercise was the primary intervention for LBP treatment and had a minimum follow-up of 12 weeks. A planned analysis of SRF and outcome associations was not conducted due to insufficient data.

RESULTS

A total of 10,292 studies were identified and 157 studies included. Fewer than half (47.1 %) reported any SRFs at baseline. Socioeconomic position (42.7 %) was most frequently reported, followed by social relationships (17.8 %), race/ethnicity/cultural context (8.3 %), residential/community context (1.3 %), and gender (0.6 %). Four studies incorporated SRFs in their outcome analyses; one examined associations with outcomes and found no significant association.

CONCLUSION

SRFs are underreported in RCTs of exercise interventions for LBP and are rarely analyzed in relation to primary outcomes, limiting our understanding of their impact. Future trials should prioritize collecting and reporting SRFs at baseline and incorporating them in outcome analyses to assess their influence on outcomes.

Interactions between Insomnia, Sleep Disordered Breathing and Cardiometabolic Risk in Patients Complaining of Pain in the Orofacial Region

The existence of intersected pathways between the mechanisms of insomnia, sleep-disordered breathing and persistent/chronic pain has been documented. Such concurrence will eventually contribute to a higher burden of cardiometabolic diseases, a main cause of death worldwide. The aim of this study was to evaluate the interactions between insomnia, sleep-disordered breathing, cardiometabolic risk, and psychosocial stress in patients seeking care at an orofacial pain clinic. Anonymized data of 1236 patients seeking care at the orofacial pain unit of the University of Zurich were analysed. Prevalence data was estimated for insomnia, sleep disordered breathing/sleep apnea and increased risk of a combination of insomnia and sleep disordered breathing/sleep apnea, both regarding demographics and cardiometabolic risk factors. Psychosocial stress factors acting as additional cardiometabolic risk factors were assessed. Among patients with persistent orofacial pain, increased risk of combination of insomnia and sleep disordered breathing/ sleep apnea was present in 11.5% of cases, and it was likely to increase psychosocial stress as an aditional independent risk factor for cardiometabolic disorder.

Social Determinants and Consequences of Pain: Toward Multilevel, Intersectional, and Life Course Perspectives

Despite wide endorsement of a biopsychosocial framework for pain, social aspects of pain remain rarely addressed in the context of pain prevention and management. In this review, we aim to 1) examine the broad scope of social determinants and consequences of pain and their interactions across multiple levels of organization, and 2) provide a framework synthesizing existing concepts and potential areas for future work on social aspects of pain, drawing upon socioecological, intersectional, and life course approaches. Integrating interdisciplinary theory and evidence, we outline pathways through which multilevel social factors and pain may affect each other over time. We also provide a brief summary of intrapersonal aspects of pain, which are thought to operate at the interface between individuals and the social context. Progressing from micro- to macrolevel factors, we illustrate how social determinants of pain can directly or indirectly contribute to pain experiences, expression, risk, prognosis, and impact across populations. We consider 1) at the interpersonal level, the roles of social comparison, social relatedness, social support, social exclusion, empathy, and interpersonal conflict; 2) at the group or community level, the roles of intimacy groups, task groups, social categories, and loose associations; and 3) at the societal level, the roles of political, economic, and cultural systems, as well as their policies and practices. We present examples of multilevel consequences of pain across these levels and discuss opportunities to reduce the burden and inequities of pain by expanding multilevel social approaches in pain research and practice. PERSPECTIVE: Despite wide endorsement of a biopsychosocial framework for pain, social aspects of pain are often unclearly defined, hindering their use in pain prevention, management, and research. We summarize the scope of social aspects of pain and provide a framework synthesizing existing concepts and potential areas for future work.

The Relationship Between Neighborhood Disadvantage and Markers of Chronic Pain Risk: Findings From the Oklahoma Study of Native American Pain Risk (OK-SNAP)

Socioeconomic disadvantage contributes to health inequities, including chronic pain. Yet, research examining socioeconomic disadvantage and pain risk in Native Americans (NAs) is scant. This exploratory analysis assessed relationships between socioeconomic position (SEP), ethnicity, and neighborhood disadvantage on pronociceptive processes in 272 healthy, chronic pain-free NAs (n = 139) and non-Hispanic Whites (NHWs, n = 133) from the Oklahoma Study of Native American Pain Risk (OK-SNAP). Neighborhood disadvantage was quantified using the Area Deprivation Index (ADI). Regression models tested whether ADI predicted pain-promoting outcomes (ie, peripheral fiber functionality, pain sensitivity, pain and nociceptive amplification, and endogenous pain inhibition) above-and-beyond SEP and ethnicity. The Ethnicity × ADI interaction was also tested. Of the 11 outcomes tested, 9 were not statistically significant. Of the significant findings, neighborhood disadvantage predicted impaired inhibition of the nociceptive flexion reflex above-and-beyond SEP and ethnicity. Additionally, ethnicity moderated the relationship between ADI and warm detection threshold; disadvantage was associated with higher thresholds for NAs, but not for NHWs. Together, the results suggest neighborhood disadvantage is associated with reduced C-fiber function and impaired spinal inhibition, thus pointing to a role of neighborhood disadvantage in the relationship between the environment and pain inequities. PERSPECTIVE: This study assessed neighborhood socioeconomic disadvantage and pronociceptive processes in chronic pain-free Native Americans (NAs) and non-Hispanic Whites (NHWs). Irrespective of ethnicity, greater neighborhood disadvantage predicted less descending inhibition of spinal nociception. Neighborhood disadvantage was associated with a marker of C-fiber impairment (higher warm detection threshold) in NAs only.

The Relationship Between Experienced Discrimination and Pronociceptive Processes in Native Americans: Results From the Oklahoma Study of Native American Pain Risk

Native Americans (NAs) have higher pain rates than the general U.S. population. It has been found that increased central sensitization and reduced pain inhibition are pronociceptive processes that increase pain risk; yet, little attention has focused on the influence of psychosocial factors. Discrimination is a psychosocial factor associated with increased pain in other minoritized groups; however, it is unclear whether it also promotes pain in NAs. This study analyzed data from 269 healthy, pain-free participants (N = 134 non-Hispanic whites [NHWs], N = 135 NAs) from the Oklahoma Study of Native American Pain Risk. Experienced discrimination was measured using the Everyday Discrimination Scale (EDS). Nociceptive processes were measured via static measures of spinal sensitivity (nociceptive flexion reflex [NFR] threshold, 3-stimulation NFR threshold), temporal summation of pain (TS-Pain) and nociceptive flexion reflex (TS-NFR), and conditioned pain modulation of pain (CPM-Pain) and NFR (CPM-NFR). Results demonstrated that greater discrimination was associated with enhanced TS-NFR and impaired CPM-NFR but not static measures of spinal sensitivity or measures of pain modulation (TS-Pain, CPM-Pain). Although the effects of discrimination on outcomes were similar in both groups (not moderated by ethnicity), NAs experienced higher levels of discrimination and therefore discrimination mediated a relationship between ethnicity and impaired CPM-NFR. This indicates experienced discrimination may promote a pain risk phenotype in NAs that involves spinal sensitization resulting from impaired inhibition of spinal nociception without sensitization of pain experience. PERSPECTIVE: This study found that discrimination was associated with spinal sensitization and impaired descending inhibition of spinal nociception. These findings bolster our understanding of how social stressors experienced disproportionately by minoritized groups can contribute to pain outcomes.