Adaptive body awareness predicts fewer central sensitization-related symptoms and explains relationship between central sensitization-related symptoms and pain intensity: A cross-sectional study among individuals with chronic pain

Abstract

Background:

Central sensitization (CS), defined as the amplification of neural signaling within the CNS that elicits pain hypersensitivity, is thought be a characteristic of several chronic pain conditions. Maladaptive body awareness is thought to contribute and maintain CS. Less is known about the relationship between CS and adaptive body awareness.

Purpose:

This cross-sectional study investigated relationships among self-reported adaptive body awareness (Multidimensional Interoceptive Awareness Scale-2; MAIA-2), CS-related symptoms (Central Sensitization Inventory; CSI), and pain intensity and further delineate potential direct and indirect links among these constructs.

Methods:

Online surveys were administered to 280 individuals with chronic pain reporting elevated CSI scores. Strategic sampling targeted respondents to reflect the 2010 census. Pearson’s correlations characterized overall relationship between variables. Multiple regression analyses investigated potential direct links. A path analysis assessed mediational effects of CS-related symptoms on the relationship between adaptive body awareness and pain intensity.

Results:

CSI demonstrated strong, inverse correlations with some MAIA-2 subscales, but positive correlations with others. Higher CSI scores predicted greater pain intensity (b = 0.049, p ≤ 0.001). Two MAIA-2 subscales, Not-Distracting (b = −0.56, p ≤ 0.001) and Not-Worrying (b = −1.17, p ≤ 0.001) were unique predictors of lower CSI. Not-Distracting (b = −0.05, p = 0.003) and Not-Worrying (b = −0.06, p = 0.007) uniquely predicted lower pain intensity. CSI completely mediated the relationship between adaptive body awareness and pain intensity [point estimate = −0.04; 95% bootstrap confident intervals (CI) = −0.05 to −0.02].

Conclusions:

Findings also support future research to explore causal relationships of variables. Findings suggest that frequency of attention to bodily sensations is distinct from cognitive-affective appraisal of bodily sensation, and the two distinct higher order processes may have divergent influences on perceived pain and CS-related symptoms. Results also support future research to explore causal relationships of variables.

INTRODUCTION

Chronic pain affects more people in the United States than diabetes, heart disease, cancer, and stroke combined.¹ Chronic pain refers to pain that impacts daily functioning on most or all days over the past 6 months.² Neuroscience research suggests injuries and/or inflammatory processes may trigger change in pain processing in the peripheral and central nervous system (CNS), which is thought to contribute to the development and maintenance of chronic pain.^3–7 One proposed mechanism of the alterations in central pain processing is central sensitization (CS) defined as the amplification of neural signaling within the CNS that elicits pain hypersensitivity.^8–10 CS is thought be a predominant characteristic of fibromyalgia, chronic fatigue, irritable bowel syndrome, and chronic whiplash disorders.^11–13 Further, CS is thought to contribute to the pain experience in some individuals suffering from migraines,¹⁴ chronic low back pain,¹⁵ myofascial pain syndrome,¹⁶ chronic pelvis pain,¹⁷ and cancer-related pain.¹⁸ Patients with CS report greater severity, disability, and chronicity of clinical pain when compared to pain patients without CS^19,20 and have been associated with a poor prognosis,²¹ suggesting CS has important clinical implications.

Our understanding of CS is incomplete; however, several proposed top-down physiological mechanisms include: (a) increased membrane excitability and synaptic efficacy of dorsal horn neurons,²² (b) reduced inhibition of descending pathways,²³ and (c) long-term potentiation of neuronal synapses in the anterior cingulate cortex (ACC).²⁴ A proposed bottom-up mechanism that may drive CS is an amplified stress response that triggers the release of pro-inflammatory cytokines and activation of spinal cord glia.^25,26 A systematic review reported CS is associated with changes in brain structure and function. Specifically, individuals with CS have been found to have reduced gray matter volume in brain regions associated with affective pain processing, including threat appraisal and pain unpleasantness (e.g., cingulate and insular), stress (i.e., parahippocampal gyrus), and decreased functional connectivity in the descending pain-modulating system.²⁷ Taken together, it appears that for individuals presenting with CS, the brain may be “getting better at pain,” evidenced by accelerated ascending pain facilitation and reduced descending pain inhibition.

Central sensitization can be inferred clinically from the presence of pain hypersensitivity,²⁸ frequently assessed via quantitative sensory testing.²⁹ Screening tools, such as the Central Sensitization Inventory (CSI) have also been developed.³⁰ The CSI is a validated and well-established self-report questionnaire that identifies symptoms thought to be related to underlying physiological mechanisms of CS. The CSI has strong psychometric properties and scores have been significantly and positively associated with pain intensity, pain interference, and pain disability.^31,32 CSI scores have also been associated with biological and physiological markers of CS,^33,34 though the literature is still emergent and inconclusive. A score of 40 or higher on the CSI has been recommended as a reasonable cutoff to alert health care professionals that a patient’s symptom presentation may indicate the presence of CS.²⁰ Higher CSI scores (above the proposed 40-point cutoff) have been found to predict higher dosages of post-surgical analgesics and more severe post-surgical pain intensity ratings among patients who underwent a total knee arthroplasty,³⁵ and increased pain disability among patients with musculoskeletal disorders in primary care settings.³⁶ The CSI has also been associated with individual differences in body awareness, supporting extant theories that suggest psychosocial factors can amplify or inhibit CS-related symptoms.^37,38 Body awareness involves an attentional focus on and awareness of internal body sensations, including sensations of proprioception and interoception. Proprioception is the perception of joint angles and muscle tensions, movement, posture, and balance. Interoception is the perception of all sensations from inside the body, including the perception of physical sensations related to internal organ function (e.g., heartbeat, respiration, autonomic nervous system activation related to emotions).^39,40 Much of these perceptions remain unconscious. However, in contrast to the traditional view of body awareness,⁴¹ a growing body of literature demonstrates that body awareness is a product of conscious perception of sensations that is modified by complex bidirectional interactive evaluative functions and influenced by quality of attention, appraisal, beliefs, past experience, expectations, and social and environmental contexts.^40,42–50 Reflecting the complexity of this construct, Mehling et al. operationally defined body awareness as sensory awareness that originates from the body’s physiological state, involving interactive processes (including pain and emotion), actions (including movement), and appraisal that are shaped by the person’s attitudes, beliefs, and experience in their social and cultural context.⁵¹ In this way, body awareness is understood as an iterative process requiring the interplay between perception of, and attention to, bodily sensations and the cognitive-affective appraisal of these bodily sensations. A detailed summary of the current literature and understanding of this multi-dimensional construct has been previously published.⁵¹

Body awareness, as defined above, can be either adaptive or maladaptive according to higher-order processes, including attention to bodily sensation and cognitive-affective appraisal of bodily sensation. These distinct styles of attention and appraisal have been identified by their discrete neural activation and connectivity in the brain,⁴³ and in pain research, have been reported to be of prognostic key importance.⁵² For example, previous research found that subjects who appraised sensations of normal quality and intensity, as intense and disturbing, were less accurate in detecting subtle bodily sensations.^53,54 Thus, the ability to attend to subtle bodily sensations can be viewed as a process distinct from the tendencies of appraisal of sensation (i.e., threat appraisal, pain unpleasantness).

Maladaptive body awareness has been characterized as a style of attention to bodily sensation that involves distracted avoidance, ignoring, or suppression of perceptions of sensation. It is also characterized as a tendency to respond to bodily sensation with beliefs of catastrophic outcomes or to apprise bodily sensations as a threat to bodily integrity.^43,47,51 Maladaptive body awareness is thought to enhance hypersensitivity in central pain processing through activation of limbic brain regions, which, in turn, contributes to and sustains CS,^55–58 thereby producing a sympathetic stress response and increased physiologic arousal.

Constructs related, yet distinct, from maladaptive body awareness include hypervigilance and pain catastrophizing. Rollman defined hypervigilance as an enhanced state of sensory sensitivity accompanied by an exaggerated scan or search for threatening information.⁵⁹ Pain catastrophizing is a multifaceted construct defined as negative emotions focused on factors of hopelessness, magnification, and rumination in response to chronic pain.⁶⁰ Congruent with the fear-avoidance model of pain, hypervigilance and pain catastrophizing gives rise to pain-related fear and anxiety, as well as associated safety seeking behaviors such as avoidance/escape, which can paradoxically exacerbate persistent pain.

In contrast, adaptive body awareness may take the form of an attentional stability on bodily sensations.^51,61 This increased awareness may consist of “concrete somatic monitoring” and “sensory discrimination” of precise details and present-moment characteristics in physical sensations, devoid of cognitive-affective reactivity to, or appraisal of, sensation.^62,63 The capacity to move from thinking about physical symptoms (e.g., interpreting, appraising, ruminating with fearful, hypervigilance) to a state of perceptual attentive presence within the body, is considered adaptive body awareness.^37,64,65 Individuals with adaptive body awareness are more likely to attend to and view bodily sensations as informative for decision-making. This increased intention to attend to bodily sensation, devoid of negative appraisals (e.g., threat or unpleasantness) is thought to afford more skillful response selection to maintain homeostasis.^{43–45,66–68}

Adaptive body awareness has been associated with favorable outcomes for chronic pain (For extensive review, see Mehling et al., 2009).⁵¹ Adaptive body awareness has been found to be associated with decreased pain unpleasantness,⁶⁹ increased pain tolerance,⁶³ increased parasympathetic activation,⁶³ and increased descending pain inhibition.⁵⁷ To the authors knowledge, no study to date has documented the association between adaptive body awareness and self-reported symptoms of CS, as measured by CSI. Greater understanding into the psychological processes that are associated with the CSI may further our understanding of this frequently used measurement tool and potentially inform promising new directions to prevent or mitigate the development or maintenance of CS-related symptoms.

Aims of the current study

The overarching purpose of this cross-sectional study was to investigate the relationships among self-report measures of adaptive body awareness, CS-related symptoms, and pain intensity among individuals with chronic pain who endorse elevated levels of CS-related symptoms. We hypothesized that: (1) adaptive body awareness would be inversely related to the CSI and pain intensity. Our second aim was to further delineate potential direct and indirect links among these constructs. We hypothesized that: (2a) higher CSI scores would predict higher pain intensity, (2b) more adaptive body awareness would predict lower CSI scores and pain intensity, and (2c), CSI would partially explain the inverse relationship between adaptive body awareness and pain intensity.

MATERIALS AND METHODS

Participants and procedures

The Oregon Health & Science University review board approved all study procedures and informed consent was obtained from all participants. From May to June of 2020, Qualtrics (Qualtrics, Provo, UT) was contracted to recruit a national sample of English-speaking participants, 18 years or older in the United States. Qualtrics provided a randomly selected sample from traditional, actively managed, double-opt-in market research panels using dynamic surveys. Strategic sampling was used to target respondents as to reflect the 2010 census in the domains of race, geographic location, age, gender, ethnicity, education, and income.

Eligible participants were English-speaking adults, ages 18–70, who had internet access and reported chronic pain, as defined by the National Institute of Health Task Force for Research Standards for Chronic Pain (RTF).⁵⁷ The RTF recommended that “chronic pain” be defined as a pain problem that has persisted at least 3 months, and has resulted in pain on at least half the days in the past 6 months. Following RTF guidelines, we included 2 questions to define chronicity: (1) “How long the pain has been an ongoing problem for you?” and (2) “How often has pain been an ongoing problem for you over the past 6 months?” A response of “greater than 3 months” to question 1 and a response of “at least half the days in the past 6 months” to question 2 would indicate chronic pain. Exclusion criteria included the endorsement of being currently involved with a worker’s compensation or currently undergoing a disability application or claim. Of the 2743 participants initially recruited, following screening, 280 met inclusion and exclusion criteria, consented to the study, and remotely completed an online battery of validated questionnaires. Questionnaires were presented in a randomized order to reduce ordering effects. All questionnaires were completed remotely and online in a single administration session, lasting an average of 29 minutes. This study is a secondary data analysis, using only a subsection of a larger survey battery designed to examine the psychometric properties of a new self-report survey instrument.

Measures

Demographic information collected included age, sex identified at birth, gender, race/ ethnicity, education, employment, income, relationship status, chronic pain duration, and pain location. Because the survey was conducted during the COVID-19 pandemic, endorsement of sheltering in place status was also collected.

The Central Sensitization Inventory-Part A (CSI)³⁰ assesses key polysomatic symptoms associated with hypersensitivity of pain processing in the CNS, present within many chronic pain disorders. Higher scores indicate greater symptom severity. CSI demonstrated excellent reliability [Cronbach’s alpha (α) = 0.93].

The Multidimensional Assessment of Interoceptive Awareness (MAIA-2)⁷⁰ is a 37-item instrument that assesses adaptive body awareness in eight subscales, organized into five domains:

1. General Awareness of Body Sensations domain is measured via the Noticing scale, which refers to the awareness of comfortable, neutral, and uncomfortable body sensations.

2. Emotional and Attentional Responses to Bodily Sensations domain is measured via the Not-Worrying and the Not-Distracting subscales. Not-Worrying scale assesses the tendency not to worry or experience emotional distress with sensations of pain or discomfort. Not-Distracting scale assesses the tendency to not ignore or distract oneself from uncomfortable body sensations such as pain.

3. Attention Regulation domain is measured by the Attention Regulation scale, which captures the tendency to maintain and regulate attention to body sensations.

4. Awareness of Mind-Body Integration domain is measured by the Emotional Awareness, Self-Regulation and Body Listening subscales. Self-Regulation refers to the ability to control psychological distress by consciously attending to body sensations. Emotional Awareness refers to consciousness of the interrelation of emotions and body sensations. Body Listening refers to active listening to the body for insight.

5. Tendency to Trust Body Sensations domain is measured by the Body Trusting scale. Higher scores are thought to indicate more adaptive body awareness.

All factors demonstrated acceptable to excellent reliability (Noticing, α = 0.71, Not-Worrying, α = 0.64; Not-Distracting, α = 0.84; Attentional Regulation, α = 0.90; Emotional Awareness, α = 0.85; Self-Regulation, α = 0.87; Body Listening, α = 0.85; Body Trusting, α = 0.87).

The Pain Intensity Scale is a one-item scale that assesses pain intensity over the last seven days using a numerical rating scale of 0–10. Higher scores indicate more pain. The numerical rating scale for pain intensity is the most commonly used measure for pain intensity due to ease of administration and scoring.⁷¹

Data analytic plan

Descriptive statistics of means (M) and standard deviations (SD) were calculated for all variables. Prior to data analyses, all variables were examined in the Statistical Package for the Social Sciences (SPSS)-26 (IBM Corp, Armonk, NY) to evaluate data compliance with parametric analysis assumptions. To test the first hypothesis, Pearson’s correlations were conducted to characterize the overall relationship between variables. To test the second hypothesis, three hierarchical multiple regression analyses were used to investigate if: (1) CS-related symptoms predicted pain intensity; and if (2) adaptive body awareness uniquely predicted CS-related symptoms and (3) pain intensity.

To assess the possibility of a mediational effect of CS-related symptoms on the relationship between adaptive body awareness and pain intensity, we conducted path analyses using the PROCESS procedure for SPSS.⁷² The MAIA-2 assesses eight aspects of body awareness. Given that no study has reported on the relationship between adaptive body awareness and CSI scores, post hoc results from regression analyses informed, which MAIA-2 scales were entered into the meditational model. A path analysis uses unstandardized regression techniques to explore the predictive relationships between variables. To compute an estimate of the indirect effects, we employed a bootstrapping method. Bootstrapping is a non-parametric resampling method that bypasses assumptions of normality common to traditional tests of mediation, and is, thus, more powerful.^73,74 Specifically, 5000 samples of the original size were taken from the obtained data (with replacement after each specific number was selected), and indirect effects were calculated in each sample. The mean indirect effect computed over each of these 5000 samples was used to compute the point estimate. The bias corrected and accelerated 95% confidence intervals (CI; i.e., with z score-based corrections for bias due to the underlying distribution) were then examined, and if these intervals did not contain 0, the point estimate of the indirect effect was considered significant. The study was conducted during the COVID-19 pandemic; therefore, a binary endorsement of sheltering place was also entered as covariates. Covariates were kept in the model if their p value was less than 0.10. The alpha level was set at 0.05 (two-tailed) for all analyses.

RESULTS

Participant demographics are reported in Table 1. The mean age was 45 years (SD = 15) and 48% identified as female (Table 1). Average level of pain intensity over the last seven days was 5 (SD = 2.0) on a 0–10 Numerical Rating Scale. All participants in the sample (n = 280) reported moderate to severe CS-related symptoms, indexed by a score greater than 40 on the CSI (M = 67.78; SD = 16.26).²⁰ Men and women did not differ in reported pain intensity, CSI, or MAIA-2. No differences were noted in those individuals who reported sheltering in place among variables of interest. Descriptive statistics are reported in Table 2.

TABLE 1.

Participant demographics (n = 280)

Variable	M	SD
Age	45	15.44
	n	%
Sex at birth
Male	144	48
Female	133	51
Intersex	3	>1
Race/Ethnicity
Hispanic/Latinx/Spanish	48	17
Black	33	12
Asian	10	5
Native American	7	5
White	206	61
Education
Less than High school	15	5
High school or equivalent	103	37
Some College	60	21
2-years associate degree	22	9
4-years bachelor’s degree	44	16
Master’s degree	30	11
Doctoral degree	5	2
Professional degree	1	.3
Employment
Employed	129	46
Temporarily laid off/ Unemployed	42	15
Retired	47	17
Disabled	34	12
Other	28	10
Income
Less than 30,000	64	23
30,000–50,000	52	19
50,000–70,000	53	19
80,000–100,000	28	10
100,000–150,000	80	18
>150,000	19	7
Relationship status
Married	131	47
Widowed	9	3
Divorce/Separated	42	15
Never Married	92	33
Chronic pain duration
3–6 months	26	9
6–12 months	33	12
1–3 years	66	24
3–5 years	52	18
5–10 years	36	13
More than 10 years	67	24
Pain location
Neck and Back Pain	223	80
Migraines	1	4
Hip/ Pelvis	5	2
Other	34	12
Sheltering in Place	156	56

TABLE 2.

Mean, standard deviations, and bivariate correlations among variables (n = 280)

Variables	Mean (SD)	1	2	3	4	5	6	7	8	9	10
1. CSI	67.78 (16.26)	—	0.39**	−0.38**	−0.24*	−0.10	−0.05	0.36**	0.04	−0.20*	0.28**
2. Pain intensity	5.34 (2.06)	0.39**	--	−0.13*	−0.19*	0.10	0.06	0.21*	0.7	−0.02	0.19*
3. MAIA-2 Not worry	20.65 (5.15)	−0.38**	0.13*	—	−0.07	0.22**	0.14*	−0.22**	−0.09	0.22**	−0.21**
4. MAIA-2 Not distract	18.30 (6.67)	−0.24**	−0.19**	−0.07	—	−0.15*	−0.08	−0.29**	−0.04	−0.07	−0.19*
5. MAIA-2 Attentional regulation	31.32 (8.02)	−0.10	0.10	0.22**	−0.15*	—	0.62**	0.28**	0.54**	0.54**	0.41**
6. MAIA-2 Self-regulation	17.62 (5.38)	−0.05	0.06	0.14*	−0.08	0.62**	—	0.21**	0.71**	0.55**	0.47**
7. MAIA-2 Noticing	14.87 (3.80)	0.36**	0.21**	−0.22**	−0.29**	0.28**	0.23**	—	0.32**	0.11	0.50**
8. MAIA-2 Body listening	12.26 (4.17)	0.04	0.07	−0.09	−0.04	0.54**	0.71**	0.32**	—	0.46**	0.56**
9. MAIA-2 Body trusting	14.32 (4.43)	−0.20*	−0.02	0.21**	−0.07	0.54**	0.55**	0.11	0.46**	—	0.26**
10. MAIA-2 Emotional awareness	24.63 (6.12)	0.28**	0.19**	−0.22*	−0.19*	0.41**	0.48**	0.50**	0.56**	0.26**	—

Abbreviations: CSI, Central Sensitization Inventory; MAIA-2, The Multidimensional Interoceptive Awareness Scale-2.

^*p < 0.05;

^**p < 0.001.

Bivariate correlations

Duration of pain was positively associated with the CSI. Pain intensity and the CSI were found to be significantly and inversely associated with some aspects of body awareness, as measured by two subscales in the Emotional and Attentional Responses to Bodily Sensations Domain of the MAIA-2, Not-Distracting and Not-Worrying. The CSI was also significantly and inversely correlated with the Body Trusting scale. Conversely, pain intensity and the CSI were significantly and positively associated with the Noticing and Emotional Awareness MAIA-2 subscales. Correlations are displayed in Table 2.

Regression analyses

The first hierarchical multiple regression analysis revealed CSI scores predicted greater levels of pain intensity. In step one, age, sex at birth, and pain duration were entered into the model, given previous reports of these demographic variables correlating with pain intensity. In step two, CSI was entered. Higher scores on the CSI predicted greater pain intensity, b = 0.049, t(1,275) = 6.92, p ≤ 0.001 and explained almost 20% of variance in pain intensity scores, R² = 0.19, F(1,274) = 16.03, p ≤ 0.001. No previous study has reported on the relationship between adaptive body awareness and CSI scores; therefore, post hoc results from bivariate correlations informed, which MAIA-2 scales were entered into the multiple regression models.

The second regression analysis revealed that some aspects of body awareness predicted CSI scores. In step one, age, sex at birth, and pain duration were entered into the model. In step two, Not-Distracting, Not-Worrying, and Body Trusting subscales of MAIA-2 were entered. Combined, this model explained a substantial portion of the variance in CSI scores (R² = 0.29, F(1,273) = 18.19, p ≤ 0.001). Higher scores on Not-Distracting (b = −0.56, t(273) = −4.54, p ≤ 0.001) and Not-Worrying (b = −1.17, t(273) = −7.13, p ≤ 0.001) were unique predictors of lower CSI scores.

A third regression analysis revealed higher scores on the Emotional and Attentional Responses to Bodily Sensations Domain of the MAIA-2, Not-Distracting (b = −0.05, t(274) = −3.04; p = 0.003) and Not-Worrying (b = −0.06, t(274) = −2.74; p = 0.007), uniquely predicted lower pain intensity, explaining 10% of the variance in pain intensity (R² = 0.10, F(1,274) = 6.21, p ≤ 0.001; Displayed in Tables 3–5).

TABLE 3.

Evaluating effects of CSI on pain intensity using linear regression analysis (n = 280)

	B SE	β	p
Step one
Sex at birth	0.09 (0.24)	0.02	0.70
Age	0.01 (0.008)	0.09	0.14
Pain duration	2.11 (0.08)	0.16	0.007*
Step two
CSI	0.05 (0.007)	0.39	≤0.001**

Abbreviation: CSI, Central Sensitization Inventory.

^*p < 0.05;

^**p < 0.001.

TABLE 5.

Effects of adaptive body awareness on pain intensity using linear regression analysis (n = 280)

	B SE	β	p
Step one
Age	0.13 (0.008)	0.09	0.14
Sex at birth	0.92 (0.24)	0.02	0.70
Pain duration	0.21(0.08)	0.16	0.007*
Step two
MAIA-2 Not-distracting	−0.05 (0.17)	−0.17	≥0.003*
MAIA-2 Not-Worrying	−0.06 (0.02)	−0.16	≥0.007*

Abbreviations: CSI, Central Sensitization Inventory; MAIA-2, Multidimensional Assessment of Interoceptive Awareness-2.

^*p < 0.05;

^**p < 0.001.

Path analysis

Given that no study has reported on the relationship between adaptive body awareness and CSI scores, post hoc results from regression analyses informed, which MAIA-2 scales were entered into the meditation model. The Emotional and Attentional Responses to Bodily Sensations Domain of the MAIA-2 was used to index body awareness. Results from the path analysis demonstrated that scores on the CSI completely mediated the relationship between adaptive body awareness and pain intensity [point estimate = −0.04; 95% bootstrap confident intervals (CI) = −0.05 to −0.02], displayed in Table 6. After accounting for CS-related symptoms, the inverse relationship between adaptive body awareness and pain intensity was no longer significant.

TABLE 6.

Mediation effects of CSI on the relationship between emotional and attentional responses to bodily sensations domain of the MAIA-2 and pain intensity (n = 280)

		95% CI
Effect	b	Lower	Upper
Total	−0.05	−0.08	−0.03
Direct	−0.02	−0.05	0.02
Indirect (mediation)	−0.04	−0.05	−0.02

Abbreviations: CSI, Central Sensitization Inventory; MAIA-2, Multidimensional Assessment of Interoceptive Awareness-2.

DISCUSSION

The overarching purpose of this cross-sectional study was to investigate relationships among self-report measures of adaptive body awareness, CS-related symptoms, and pain intensity among individuals with chronic pain who endorse clinically elevated CS-related symptoms. We hypothesized that: (1) adaptive body awareness would be inversely related to CSI and pain intensity; (2a) higher CSI scores would predict higher pain intensity, (2b) more adaptive body awareness would predict lower CSI and pain intensity, and (2c), the CSI would partially explain the inverse relationship between adaptive body awareness and pain intensity. Overall, the findings support our hypotheses and contribute to the complex literature on body awareness and chronic pain.

Supporting our first hypothesis, CSI scores and levels of pain intensity were found to be significantly and inversely associated with some domains of body awareness, as measured by the MAIA-2. Results suggest that frequency of attention to bodily sensations, is distinct from cognitive-affective appraisal of bodily sensation, and the two distinct higher-order processes may have divergent influences on perceived pain and CS-related symptoms. Specifically, the Emotional and Attentional Responses to Bodily Sensations domain of the MAIA-2 (Not-Worrying and Not-Distracting subscales) demonstrated strong, inverse correlations with the CSI and pain intensity. This domain attempts to capture the frequency of attention to bodily sensations and the tendency to not suppress, ignore, or avoid perceptions of sensations. Importantly, it also captures the tendency to not appraise a sensation as bothersome or unpleasant and to not “analyze” sensations, including worrying that something is wrong.⁶³ Findings support theories that suggest the tendency to worry less about unpleasant bodily sensations, (e.g., the individual withholds negative interpretations in response to unpleasant sensations) may buffer initial threat appraisals and associated limbic system reactivity, and thereby, reduce CS-related symptoms and associated pain intensity.^{39,64 65}

In contrast, the Noticing and Emotional Awareness MAIA-2 subscales were positively associated with CSI scores and levels of pain intensity. The Noticing scale describes the frequency of attention to uncomfortable, comfortable, and neutral body sensations and the Emotional Awareness scale describes frequency of attention to uncomfortable, comfortable, and neutral body sensations that are associated with emotions. These two subscales measure the frequency by which individuals actively scan their bodies in order to detect cues and changes in their current physical condition, also known as monitoring, without taking into account the cognitive-emotional response to, or appraisal of, that sensory awareness.⁶⁶ Previous research has suggested that for some individuals with chronic pain, increased monitoring of bodily sensations may be more likely to be paired with a hypervigilance or catastrophizing orientation, leading to excessive worry and anxiety, associated pain, stress, and depression.^67–69 Current results are congruent with a previous study that reported patients with fibromyalgia, a pain condition characterized by CS, exhibited a higher score on the Noticing MAIA subscale, when compared to healthy controls.⁷⁰ Though previous studies have documented correlations among the CSI and constructs related to maladaptive body awareness,^75,76 to the authors’ knowledge, this is the first study that demonstrates significant correlations between adaptive body awareness and the CSI.

In support of our second and third hypotheses, findings uniquely contribute to the literature by demonstrating that more adaptive body awareness, as measured by the Emotional and Attentional Responses to Bodily Sensations domain of the MAIA-2, predicted lower CSI scores and pain intensity. Additionally, a path analysis revealed that the CSI completely mediated the relationship between adaptive body awareness and pain intensity. Findings support extant theories that suggest psychosocial factors can amplify or inhibit CS-related symptoms, enhance our understanding of this frequently used measurement tool, and potentially inform promising new directions to prevent or mitigate the development or maintenance of CS-related disorders. Neuroimaging was not collected in this study; however, findings are congruent with previous brain imaging studies that suggests adaptive body awareness may afford a functional decoupling of the sensory dimensions of pain from the affective aspects of pain, whereby, individuals with greater adaptive body awareness view painful stimuli more neutrally.^54,74 These neuroplasticity changes afford greater conscious awareness of bodily signals, while simultaneously dampening down higher-order cognitions,⁷⁵ improving cognitive-affective regulation, and thus, may reduce pain facilitatory processes and increase pain inhibitory processes associated with CS.^56,66

Clinical implications of these results suggest that clinicians may consider targeting interventions that increase adaptive body awareness to address CS processes and related symptoms. There are a variety of interventions aimed to enhance body awareness (i.e., yoga, tai chi, mindfulness meditation, physical therapy, Feldenkrais Method, Alexander Technique, and Mindful Awareness in Body-Oriented Therapy).⁵¹ These intervention target learning higher-order regulation (attention, cognitive, and affective regulation) in relation to bodily sensation. For example, Mindful Awareness in Body-Oriented Therapy has been shown to improve body awareness and emotion regulation (self-report and psychophysiology) among women in substance use disorder treatment, when compared with the other study groups.⁶⁸ Further, patients with chronic pain and comorbid active depression who completed Mindfulness-Based Cognitive Therapy (MBCT), when compared to treatment as usual, demonstrated significant improvement in body awareness. Further, the positive effect of MBCT on depression severity was mediated by the Not-Distracting subscale of the MAIA-2.⁷⁷ Relatedly, neuroimaging studies have shown that mindfulness meditation and yoga, in particular, may be able to downregulate painful stimuli by increased sensory processing of the pain sensation itself, rather than by distraction away from it, and by replacing attempts to exert more cognitive control over the pain with a distinct brain state of cognitive disengagement.⁷⁸

There are several limitations in the study that need to be considered. First, this is a cross-sectional study, and thus, does not provide a test of causal relations. Longitudinal data are preferred to cross-sectional evidence for testing associations between changes in latent traits. However, theoretical contributions can come from cross-sectional mediation analyses when viewed as a type of variance partitioning, rather than a proxy for longitudinal relations, and can be useful even if none of the variables involve a temporal dimension. This study does provide support for future clinical trials to evaluate the effects of interventions that promote adaptive body awareness to explore the causal and directional relationship of these relationships. Second, medical diagnoses for pain conditions were not confirmed. Future research should replicate this study with individuals with medically confirmed diagnoses of pain conditions. Third, the survey was conducted during the COVID-19 pandemic and approximately 56% of the sample endorsed sheltering in place. Given the scarcity of data, we do not know the effects of sheltering in place, though in this sample, sheltering in place was not correlated with any study variables. Fourth, while the CSI can give an indication of the presence and severity CS-related symptoms, future research should employ more objective indicators of CS, such as quantitative sensory testing methods. Given all participants had to report high CSI values for inclusion, our findings may not extend to other people with chronic pain and lower CSI values. Finally, this study does not include any neuroimaging data and, therefore, interpretations of results must be taken with caution.

In summary, these novel findings support the complex literature on body awareness and chronic pain, and specifically examine the relationship between body awareness, CS-related symptoms, and associated pain intensity. Results suggest that frequency of attention to bodily sensations is distinct from cognitive-affective appraisal of bodily sensation and these two higher-order processes may have divergent influences on perceived pain and CS-related symptoms. Further, our findings uniquely demonstrated that adaptive body awareness completely mediated the relationship between CS-related symptoms and pain intensity. Understanding these relationships may potentially inform more effective and personalized treatment approaches for patients suffering from CS.

TABLE 4.

Effects of adaptive body awareness on CSI using linear regression analysis (n = 280)

	B SE	β	p
Step one
Age	−0.19 (0.06)	−0.18	0.005*
Sex at birth	4.71 (1.89)	0.15	0.01*
Pain duration	2.11 (0.60)	0.22	0.001*
Step two
MAIA-2 Not-Distracting	−0.56 (0.12)	−0.23	≤0.001*
MAIA-2 Not-Worrying	−1.17 (0.16)	−0.38	≤0.001**
MAIA-2 Body Trusting	−0.38 (0.19)	−0.10	0.53

Abbreviations: CSI, Central Sensitization Inventory; MAIA-2, Multidimensional Assessment of Interoceptive Awareness-2.

^*p < 0.05;

^**p < 0.001.

What does this study add.

These novel findings suggest that frequency of attention to bodily sensations is distinct from cognitive-affective appraisal of bodily sensation and these two higher order processes may have divergent influences on perceived pain and central sensitization-related symptoms. Further, our findings uniquely demonstrated that adaptive body awareness completely mediated the relationship between central sensitization-related symptoms and pain intensity. Understanding these relationships may potentially inform more effective and personalized treatment approaches for patients suffering from central sensitization.

What is Known.

Maladaptive body awareness is thought to contribute and maintain symptoms of central sensitization. Less is known about the relationship between CS and adaptive body awareness.

DATA AVAILABILITY STATEMENT

The data that support the findings of this study are available from the corresponding author, [DC] upon reasonable request.