Background & Aims

Interoception, the ability to detect internal bodily signals, is vital for an individual’s well-being and plays a role in the aetiology and maintenance of chronic pain (Di Lernia et al, 2020). Evidence suggests interoceptive accuracy is lower in patients with chronic pain conditions compared to controls (Locatelli et al, 2023). For example, in the nociplastic pain condition fibromyalgia (FM), lower interoceptive awareness is associated with higher symptom severity (Duschek et al, 2017). Savitz et al (2018) describe a model of peripheral inflammation activating a neurally mediated interoceptive pathway, however, there is a paucity of evidence about interoceptive sensibility in the inflammatory condition rheumatoid arthritis (RA). High rates of FM are reported in RA (Gist et al, 2018). This study aims to explore interoceptive awareness in newly diagnosed RA patients, focusing on the prevalence of FM symptoms and their relationship with interoceptive sensibility.

Methods

An observational study of 169 adults with newly diagnosed RA recruited from rheumatology outpatient clinics at Oxford University Hospitals NHS Foundation Trust between September 2020 and June 2023. The following outcome measures were collected at baseline prior to commencing treatment with disease-modifying rheumatological agents: Multidimensional Assessment of Interoceptive Awareness (MAIA), Central Sensitisation Inventory (CSI), Symptom Severity Scale (SSS), Insomnia Severity Index (ISI), Patient Health Questionnaire-9 (PHQ-9), General Anxiety Disorder-7 (GAD-7), symptom duration, average pain on a numerical pain rating scale as well as the 2016 American College of Rheumatology Diagnostic Criteria for FM. Independent t-tests were performed to compare any significant difference in measures between those who fulfilled the diagnostic criteria for FM and those who did not. Pearson’s correlation was used to investigate the associations between the MAIA and the other measures listed.

Results

Of 169 RA patients (average age 60.8 years, 67% (n=114) female), 25% (n=42) met the 2016 American College of Rheumatology Diagnostic Criteria for FM. RA participants meeting FM criteria reported significantly higher scores on CSI [t(167)=2.303, p=.023], SSS [t(167)=3.100, p=.002), ISI [t(167)=3.880, p<.001], and PHQ9 [t(167)=3.162, p=.002] compared to those who did not meet FM criteria. Significant differences in average pain, MAIA and GAD7 scores were not observed. RA patients meeting FM criteria had higher scores on the following measures even when controlling for age and gender: CSI (F=12.417, p<.001), SSS (F=16.180, p<0.001), ISI (F=13.691, p<.001), PHQ9 (F=14.408, p<.001), and GAD7 (F=7.198, p<.008). MAIA was positively correlated with SSS in those meeting FM criteria (r(40)=.396, p=.009) compared to those who did not (r(125)=-.116, p=.195).

Conclusions

Consistent with the literature, this study shows that a significant percentage of patients with RA meet the criteria for diagnosis of FM. After controlling for age and gender, these participants present with more features of central sensitisation, greater symptom severity, worse sleep, and lower mood. It is interesting that interoceptive sensibility, as measured by the MAIA, was not significantly different between those who did and did not meet FM criteria. Other variables not accounted for in this study may have an effect, or more accurate measures of subjective interoception should be used e.g. heartbeat perception score (Schandry, 1981). These results suggests that those with inflammatory pain have disrupted body to brain signalling (or beliefs concerning one’s own interoception [Murphy et al, 2019]), worsened by symptom severity in the presence of nociplastic pain. Altered interoceptive sensibility is rarely addressed in treatment for RA and warrants further investigation.

References

Di Lernia D, Lacerenza M, Ainley V, Riva G. (2020) Altered interoceptive perception and the effects of interoceptive analgesia in musculoskeletal, primary, and neuropathic chronic pain conditions. J Pers Med. 29;10(4):201-225.

Duschek S, Montoro C, Reyes Del Paso G. (2017) Diminished interoceptive awareness in fibromyalgia syndrome. Behav. Med. 43(2):100–107.

Gist A, Guymer E, Eades L, Leech M, Littlejohn G. (2018) Fibromyalgia remains a significant burden in rheumatoid arthritis patients in Australia. Int J Rheum Dis. 21(3):639-646.

Locatelli G, Matus A, James R, Salmoirago-Blotcher E, Ausili D, Vellone E, Riegel B. (2023) What is the role of interoception in the symptom experience of people with a chronic condition? A systematic review. Neurosci. Biobehav. Rev. 148:105142.

Murphy J, Catmur C, Bird G.(2019) Classifying individual differences in interoception: Implications for the measurement of interoceptive awareness. Psychon Bull Rev 26:1467–1471.

Schandry R. (1981) Heartbeat perception and emotional experience. Psychophysiol 18:483–488.

Valenzuela-Moguillansky C, Reyes-Reyes A and Gaete MI (2017) Exteroceptive and interoceptive body-self awareness in fibromyalgia patients. Front. Hum. Neurosci. 11:117

Presenting Author

Amanda Wall

Poster Authors

Amanda Wall

MSc

University of Oxford

Lead Author

Luke Aldridge-Wadden

PhD

Oxford Health NHS Foundation Trust

Lead Author

Eoin Kelleher

MB BCh MSc FCAI

University of Oxford

Lead Author

Vishvarani Wanigasekera

MRCP

Wellcome Centre for Integrative Neuroimaging, FMRIB Centre, Nuffield Department of Clinical Neurosci

Lead Author

Anushka Irani (nee Soni)

Mayo Clinic Florida

Lead Author

Topics

  • Specific Pain Conditions/Pain in Specific Populations: Rheumatology, Arthritis, and Other