Cigarette smoking, stress-induced analgesia and pain perception in men and women

A multi-center study on the use of lidocaine thermogel for pain control in outpatient operative hysteroscopy

OBJECTIVES

This study aimed to explore the use of an anesthetic lidocaine thermogel in outpatient operative hysteroscopies. Specifically, it assessed the safety, tolerability, and ease of use of the gel, as well as its potential for pain reduction during the procedure.

STUDY DESIGN

This was a multicenter observational study conducted in 9 gynecological units between March 2023 and January 2024. The study included adult women scheduled for outpatient operative hysteroscopies, excluding those with hypersensitivity to the product or recent participation in other clinical studies. The target sample size was 60 to account for potential dropouts. Data collection was electronic, and SPSS was used for analysis. The study assessed visibility conditions, procedure duration, pain scores at different stages of the procedure, and adverse event frequency. Statistical analyses utilized descriptive statistics, Student's t-tests, Wilcoxon and Friedman tests, and Chi-Square or Fisher tests as appropriate. Binary logistic regression was applied to identify factors influencing gel volume.

RESULTS

All 60 participants met the inclusion criteria. The mean age was 45.5 (SD 8.8) years, with a mean BMI of 27.0 (SD 5.6) kg/m2. Medical histories were reported in 46.7% of participants, and 50% had undergone previous gynecological surgeries. Prior to the procedure, 51.8% of participants took analgesics. The average procedure duration was 13.9 (SD 15.1) minutes. Pain scores were collected at different stages of the procedure, with median VAS scores ranging from 0 to 5 out of 10. In 50% of cases, the quality of vision during the procedure was rated 9 or higher on a 10-point scale. The full recommended dose of thermogel was administered in 91.7% of cases. The mean gel volume used was 7.0 (SD 1.9) milliliters. Regression analysis showed that younger age and a history of abortions or childbirth were significantly associated with higher gel volume use.

CONCLUSIONS

The anesthetic thermogel demonstrated effectiveness in managing pain during outpatient operative hysteroscopies, with median pain scores ranging from 0 to 5 out of 10 across different stages of the procedure. The gel showed a favorable safety profile, with only 15% of participants reporting adverse effects, all of which were minor and resolved satisfactorily. The high rate of complete gel application (91.7% of cases) and positive physician feedback suggest good tolerability and ease of use. Further research is recommended to evaluate the gel's efficacy in other gynecological procedures and to optimize application protocols based on patient-specific factors such as age and reproductive history.

Tobacco smoking and its impact on pain intensity of temporomandibular disorders: A systematic review and metanalysis

BACKGROUND

Temporomandibular disorders (TMDs) encompass a spectrum of orofacial conditions characterised by pain and dysfunction in the temporomandibular joint and surrounding structures. Tobacco smoking has been posited as a potential factor influencing the prevalence and intensity of TMD. However, the nature and extent of this relationship remain unclear due to variations in study outcomes. This systematic review aimed to consolidate existing research findings to elucidate the association between tobacco smoking and TMD pain intensity.

METHODS

A comprehensive search of electronic databases was conducted to identify relevant studies published up to June 2023. Studies investigating the relationship between tobacco smoking and TMD pain were included. Data extraction was conducted by two reviewers. Quality assessment was performed using the New Castle-Ottawa scale. Review Manager 5.4 was used to quantitatively analyse the results.

RESULTS

The review included four studies employing similar TMD assessment techniques. All studies reported elevated TMD pain intensity among tobacco users, with non-smokers exhibiting lower pain intensity. The quality of the included studies was good. Meta-analytic results showed that TMD pain intensity was higher in the smokers group compared to the non-smokers group, with a weighted mean difference (WMD) of 0.65 (BPM) (95% CI: [0.10, 1.19], p = .02).

CONCLUSION

This systematic review provides a comprehensive synthesis of the existing literature on tobacco smoking and TMD symptoms. The findings underscore the multifaceted nature of the relationship between smoking and TMD pain, highlighting its clinical relevance and the need for tailored interventions. Further research is warranted to elucidate underlying mechanisms and potential moderating factors, contributing to a more nuanced understanding of this complex association.

Acute analgesic effect of nicotine vaping using three experimental pain induction tasks: a randomized, placebo-controlled laboratory study

RATIONALE

Pain and nicotine use are co-occurring conditions with a significant impact on health. Experimental evidence supports an acute analgesic effect of nicotine which may reinforce nicotine use among those with chronic pain. Evidence for nicotine analgesia have primarily been gathered in combustible cigarette users and have not been extended to electronic nicotine delivery systems (ENDS or vaping). Furthermore, the mechanisms of nicotine analgesia in humans are not well understood.

OBJECTIVES

Assess the effect of acute vaped nicotine on subjective and behavioral indices of pain sensitivity using three tasks designed to probe distinct mechanisms of analgesia.

METHODS

This study recruited ENDS users (N = 86) to undergo a paced vaping protocol followed by pain tasks in counterbalanced order. Across four sessions, participants vaped e-liquid containing nicotine or placebo, and flavor or no-flavor in a 2 × 2 within-subject design. Assessments included cold pressor, submaximal effort tourniquet to induce ischemic pain, and temporal summation of heat pain, an index of central sensitization.

RESULTS

Compared to placebo, nicotine increased cold pressor pain tolerance (ηp2 = 0.031), ischemic pain threshold (ηp2 = 0.073) and tolerance (ηp2 = 0.056) but had no effect on temporal summation of pain. Flavor did not affect pain sensitivity. Females reported greater ischemic pain sensitivity (ηp2 = 0.027) and greater reductions in craving (ηp2 = 0.086).

CONCLUSIONS

Consistent with research from tobacco smoking, analgesia may be reinforcing and contribute to nicotine dependence among ENDS users. More research on sex differences is warranted.

Pain sensitivity as a state marker and predictor for adolescent non-suicidal self-injury

BACKGROUND

The pain analgesia hypothesis suggests that reduced pain sensitivity (PS) is a specific risk factor for the engagement in non-suicidal self-injury (NSSI). Consistent with this, several studies found reduced PS in adults as well as adolescents with NSSI. Cross-sectional studies in adults with borderline personality disorder (BPD) suggest that PS may (partially) normalize after remission or reduction of BPD symptoms. The objective of the present study was to investigate the development of PS over 1 year in a sample of adolescents with NSSI and to investigate whether PS at baseline predicts longitudinal change in NSSI.

METHODS

N = 66 adolescents who underwent specialized treatment for NSSI disorder participated in baseline and 1-year follow-up assessments, including heat pain stimulation for the measurement of pain threshold and tolerance. Associations between PS and NSSI as well as BPD and depressive symptoms were examined using negative binomial, logistic, and linear regression analyses.

RESULTS

We found that a decrease in pain threshold over time was associated with reduced NSSI (incident rate ratio = 2.04, p = 0.047) and that higher pain tolerance at baseline predicted lower probability for NSSI (odds ratio = 0.42, p = 0.016) 1 year later. However, the latter effect did not survive Holm correction (p = 0.059). No associations between PS and BPD or depressive symptoms were observed.

CONCLUSION

Our findings suggest that pain threshold might normalize with a decrease in NSSI frequency and could thus serve as a state marker for NSSI.

Pleiotropy and genetically inferred causality linking multisite chronic pain to substance use disorders

Individuals suffering from chronic pain develop substance use disorders (SUDs) more often than others. Understanding the shared genetic influences underlying the comorbidity between chronic pain and SUDs will lead to a greater understanding of their biology. Genome-wide association statistics were obtained from the UK Biobank for multisite chronic pain (MCP, Neffective = 387,649) and from the Million Veteran Program and the Psychiatric Genomics Consortium meta-analyses for alcohol use disorder (AUD, Neffective = 296,974), cannabis use disorder (CanUD, Neffective = 161,053), opioid use disorder (OUD, Neffective = 57,120), and problematic tobacco use (PTU, Neffective = 270,120). SNP-based heritability was estimated for each of the traits and genetic correlation (rg) analyses were performed to assess MCP-SUD pleiotropy. Bidirectional Mendelian Randomization analyses evaluated possible causal relationships. Finally, to identify and characterize individual loci, we performed a genome-wide pleiotropy analysis and a brain-wide analysis using imaging phenotypes available from the UK Biobank. MCP was positively genetically correlated with AUD (rg = 0.26, p = 7.55 × 10-18), CanUD (rg = 0.37, p = 8.21 × 10-37), OUD (rg = 0.20, p = 1.50 × 10-3), and PTU (rg = 0.29, p = 8.53 × 10-12). Although the MR analyses supported bi-directional relationships, MCP had larger effects on AUD (pain-exposure: beta = 0.18, p = 8.21 × 10-4; pain-outcome: beta = 0.07, p = 0.018), CanUD (pain-exposure: beta = 0.58, p = 2.70 × 10-6; pain-outcome: beta = 0.05, p = 0.014) and PTU (pain-exposure: beta = 0.43, p = 4.16 × 10-8; pain-outcome: beta = 0.09, p = 3.05 × 10-6) than the reverse. The genome-wide analysis identified two SNPs pleiotropic between MCP and all SUD investigated: IHO1 rs7652746 (ppleiotropy = 2.69 × 10-8), and CADM2 rs1248857 (ppleiotropy = 1.98 × 10-5). In the brain-wide analysis, rs7652746 was associated with multiple cerebellum and amygdala imaging phenotypes. When analyzing MCP pleiotropy with each SUD separately, we found 25, 22, and 4 pleiotropic variants for AUD, CanUD, and OUD, respectively. To our knowledge, this is the first large-scale study to provide evidence of potential causal relationships and shared genetic mechanisms underlying MCP-SUD comorbidity.

Influence of smoking on patient-reported outcome measures (PROMs) in patients undergoing surgery for adult spinal deformity: a propensity score-matched analysis

PURPOSE

The purpose of this study was to determine the isolated influence of smoking in patient-reported outcome measures (PROMs) for adult spinal deformity (ASD) surgery excluding known tobacco-related complications.

METHODS

Retrospective analysis of a prospective multicenter ASD database. Patients operated on ASD with 2 year post-operative follow-up were included. Former smokers (non-active smokers) and patients developing mechanical or infectious complications were excluded. Changes of PROMs over time were analyzed using mixed models for repeated measures (MMRM). Propensity score matching (PSM) (1:1 ratio, caliper 0.10) was performed without replacement using optimum algorithm, tolerance ≤ 0.001, and estimated with 95% confidence interval (CI). PROMS in both groups were compared by paired t test or Wilcoxon signed-rank test.

RESULTS

692 out of 1246 surgical patients met our inclusion criteria. 153 smokers were matched with 153 non-smokers according to age, BMI, number of fused levels, and global tilt. After PSM both groups were homogeneous regarding baseline parameters, surgical data, and complications (mechanical complications and infection excluded). Smokers had worse baseline results for SRS-total, SRS-pain COMI-back, and ODI; smokers also showed worse 2-year outcomes for SRS-total, SRS-function, SRS-pain, SRS-self-image, and ODI. However, no differences between the two groups were found in the improvement from baseline to 2-year follow-up or in the timing of this improvement (MMRM). The proportion of patients reaching the minimal clinically important difference (MCID) after surgery was similar in the two groups, but the proportion of patients reaching patient acceptable symptom state (PASS) was significantly lower in smokers for SRS-Subtotal, SRS-function, and SRS-image.

CONCLUSION

Even in the absence of smoking-related complications, smokers had worse PROMs at baseline and 2 years after surgery with less patients achieving PASS, but similar degrees on improvement compared to non-smokers. The proportion achieving MCID was also similar between the two cohorts.

Comparison of enjoyment and energy expenditure of exergame with and without blood flow restriction in men and women

This study compared the effects of blood flow restriction (BFR) on intensity and perceived enjoyment during an exergame. Fourteen healthy young participants engaged in a boxing exergame for 20 min, with or without BFR, across two sessions. Perceived enjoyment levels were assessed using the Physical Activity Enjoyment Scale. Heart rate was monitored, and energy expenditure (EE) during exercise was calculated. A mixed model analysis of variance with repeated measures was used to evaluate differences in EE and enjoyment between exergame conditions (with and without BFR) as well as the interaction effects of these protocols with gender. Although not statistically significant, perceived enjoyment decreased with BFR inclusion for both genders. No significant differences were observed between men and women for both protocols. Regarding EE, there was no significant difference between the two groups (with and without BFR). However, a significant main effect of gender was found, with men exhibiting higher EE values in both protocols compared to women. In conclusion, exergames incorporating BFR impact perceptual responses, particularly perceived enjoyment. Furthermore, significant gender differences in EE were found, with men displaying higher values.

Sex effects in the interaction of acute stress and pain perception

ABSTRACT

A reciprocity between the stress and the pain system is recognized; however, the manner by which sex affects this reciprocity is unclear. Understanding the interactions of stress, pain, and sex may shed light on the apparent women's vulnerability to chronic pain, which often coexists with increased distress, and to affective disorders, which often coexist with chronic pain. The study's aim was to examine the effect of acute, validated, psychosocial stress on pain perception and modulation of women and men in a controlled manner. Participants were 82 women and 66 men. Heat-pain threshold, heat-pain tolerance, and pain modulation by temporal summation of pain (TSP), and pain adaptation were measured before and after exposure to the Montreal Imaging Stress Task (MIST) or to a sham task. The stress response was verified by perceived ratings of stress and anxiety, autonomic variables, and salivary cortisol. A significant stress response was obtained by the MIST among both sexes; however, women displayed a greater increase in perceived distress, and men displayed a greater increase in cortisol. Among women, TSP decreased and pain adaptation increased following the MIST, responses that were predicted by perceived distress levels. Among men, TSP increased following the MIST but was not predicted by the stress variables. In conclusion, acute stress manipulation seems to differentially affect both stress and pain responses of women and men: women exhibited stress-induced antinociception and men exhibited stress-induced pronociception. Higher perceived stress levels among women may trigger a temporary increase in pain inhibition mechanisms to serve evolutionary purposes.

The Effects of Recovery Sleep on Experimental Pain

Recent research suggests that recovery sleep (RS) has the potential to restore pain sensitivity and modulation after hyperalgesia due to preceding sleep deprivation. However, it has not yet been systematically examined whether the restoration of these pain parameters is driven by sleep characteristics of RS. Thus, the present study assessed changes in experimental pain during RS after total sleep deprivation (TSD) to test whether RS parameters predicted the restoration of the pain system. Thirty healthy participants completed one night of habitual sleep, one night of TSD and a subsequent recovery night. At-home sleep during baseline and recovery was assessed using portable polysomnography and a questionnaire. Before and after each night pressure pain thresholds (PPTs), temporal pain summation (TSP) and conditioned pain modulation (CPM) were assessed. PPTs decreased after TSD and increased following RS, indicating a restoration of pain sensitivity after hyperalgesia. RS characteristics did not predict this restoration, suggesting other mechanisms (eg, changes in serotonergic activity) underlying the observed pain changes. TSP indicated a lack of effect of experimental sleep manipulations on excitatory processes whereas CPM lacked sufficient reliability to investigate inhibitory processes. Thus, results indicate moderate effects of sleep manipulations on pain sensitivity, but not on pain modulation. PERSPECTIVE: This article highlights the potential of recovery sleep to let pain thresholds return to normal following their decrease after a night of total sleep deprivation. In contrast, endogenous pain modulation (temporal pain summation, conditioned pain modulation) was not affected by sleep deprivation and recovery sleep.

The Effect of High Nicotine Dose on Maximum Anaerobic Performance and Perceived Pain in Healthy Non-Smoking Athletes: Crossover Pilot Study

Background: In recent years, there has been intensive discussion about the positive effect of nicotine usage on enhancing sports performance. It is frequently applied through a non-burned tobacco form before physical activity. Nicotine is under the World Anti-Doping Agency (WADA) 2021 monitoring program. Therefore, study results that reveal either positive or negative effects are expected. This is the pilot study that reports the effect of 8 mg dose of nicotine on performance and perceived pain. Material and Methods: This research aimed to explore the oral intake effect of a high-nicotine dose (8 mg) on the maximum anaerobic performance and other selected physical performance parameters in healthy, well-trained adult athletes (n = 15, age 30.7 ± 3.6, BMI 25.3 ± 1.7). The cross-sectional study protocol included the oral administration of either sublingual nicotine or placebo tablets before the anaerobic load assessed by a standardized 30 s Wingate test of the lower limbs. Afterward, the Borg subjective perception of pain (CR 10) and Borg rating of perceived exertion (RPE) were evaluated. Wilcoxon signed-rank test was used for the analysis of data with a 0.05 level of significance. Results: The results revealed that oral administration of an 8 mg nicotine dose does not significantly improve any of the physical performance parameters monitored. We only reported the statistically significant positive effect in RPE (p = 0.03). Conclusion: Lower perception of pain intensity that we reported after nicotine application might be an important factor that affects performance. However, we did not report any improvement in physical performance parameters.

Novice assessors demonstrate good intra-rater agreement and reliability when determining pressure pain thresholds; a cross-sectional study

Background

Experienced assessors show good intra-rater reproducibility (within-session and between-session agreement and reliability) when using an algometer to determine pressure pain thresholds (PPT). However, it is unknown whether novice assessors perform equally well. This study aimed to determine within and between-session agreement and reliability of PPT measurements performed by novice assessors and explored whether these parameters differed per assessor and algometer type.

Methods

Ten novice assessors measured PPTs over four test locations (tibialis anterior muscle, rectus femoris muscle, extensor carpi radialis brevis muscle and paraspinal muscles C5-C6) in 178 healthy participants, using either a Somedic Type II digital algometer (10 raters; 88 participants) or a Wagner Force Ten FDX 25 digital algometer (nine raters; 90 participants). Prior to the experiment, the novice assessors practiced PPTs for 3 h per algometer. Each assessor measured a different subsample of ~9 participants. For both the individual assessor and for all assessors combined (i.e., the group representing novice assessors), the standard error of measurement (SEM) and coefficient of variation (CV) were calculated to reflect within and between-session agreement. Reliability was assessed using intraclass correlation coefficients (ICC1,1).

Results

Within-session agreement expressed as SEM ranged from 42 to 74 kPa, depending on the test location and device. Between-session agreement, expressed as SEM, ranged from 36 to 76 kPa and the CV ranged from 9-16% per body location. Individual assessors differed from the mean group results, ranging from -55 to +32 kPa or from -9.5 to +6.6 percentage points. Reliability was good to excellent (ICC1,1: 0.87 to 0.95). Results were similar for both types of algometers.

Conclusions

Following 3 h of algometer practice, there were slight differences between assessors, but reproducibility in determining PPTs was overall good.

Cortisol response to psychosocial stress, mental distress, fatigue and quality of life in coronary artery disease patients

We aimed to explore the relationship between cortisol response to psychosocial stress, mental distress, fatigue and health related quality of life (HRQoL) in individuals with coronary artery disease (CAD) after recent acute coronary syndrome (ACS). A cross-sectional study initially included 113 subjects (88% men, 53 ± 7 years) 1-3 weeks after ACS. Cortisol response was assessed by measuring salivary cortisol during Trier Social Stress Test. Mental distress was measured with Hospital Anxiety and Depression Scale, State-Trait Anxiety Inventory, and Type D Scale-14. Fatigue symptoms were evaluated using Multidimensional Fatigue Inventory 20-items, while HRQoL was assessed with 36-Item Short Form Medical Outcome Questionnaire. After conducting multivariable linear regression analyses, diminished cortisol response sampled after Public speech (T3-T1, + 15 min) was significantly associated with higher anxiety symptoms (β = -0.224; p = 0.035), while diminished cortisol response sampled after preparation time (T2-T1, + 10 min) was significantly linked with the presence of Type D personality (β = -0.290; p = 0.006; β = -0.282; p = 0.008 respectively), even after controlling for confounders (i.e., sex, age, education, New York Heart Association functional class, beta-blockers and baseline levels of cortisol measures). We found that mental distress, but not fatigue and HRQoL, was linked with blunted cortisol response during anticipation time of psychosocial stress, independently of potential covariates.

Consensus statement on smoking cessation in patients with pain

Smoking is closely associated with the development of various cancers and tobacco-related illnesses such as cardiovascular and respiratory disorders. However, data are scarce on the relationship between smoking and both acute and chronic pain. In addition to nicotine, tobacco smoke contains more than 4000 different compounds. Although nicotine is not the sole cause of smoking-induced diseases, it plays a critical role in pain-related pathophysiology. Despite the acute analgesic effects of nicotine, long-term exposure leads to tolerance and increased pain sensitivity due to nicotinic acetylcholine receptor desensitization and neuronal plastic changes. The purpose of smoking cessation interventions in smoking patients with pain is primarily not only to reduce their pain and associated limitations in activities of daily living, but also to improve the outcomes of underlying pain-causing conditions and reduce the risks of tobacco-related disorders. This statement aims to summarize the available evidence on the impact of smoking on pain and to inform medical professionals of the significance of smoking cessation in patients with pain.

No relevant differences in conditioned pain modulation effects between parallel and sequential test design. A cross-sectional observational study

Background

Conditioned pain modulation (CPM) is measured by comparing pain induced by a test stimulus with pain induced by the same test stimulus, either during (parallel design) or after (sequential design) the conditioning stimulus. Whether design, conditioning stimulus intensity and test stimulus selection affect CPM remains unclear.

Methods

CPM effects were evaluated in healthy participants (N = 89) at the neck, forearm and lower leg using the cold pressor test as the conditioning stimulus. In three separate experiments, we compared the impact of (1) design (sequential versus parallel), (2) conditioning stimulus intensity (VAS 40/100 versus VAS 60/100), and (3) test stimulus selection (single versus dual, i.e., mechanical and thermal). Statistical analyses of the main effect of design (adjusted for order) and experiment were conducted using linear mixed models with random intercepts.

Results

No significant differences were identified in absolute CPM data. In relative CPM data, a sequential design resulted in a slightly lower CPM effect compared to a parallel design, and only with a mechanical test stimulus at the neck (−6.1%; 95% CI [−10.1 to −2.1]) and lower leg (−5.9%; 95% CI [−11.7 to −0.1]) but not forearm (−4.5%; 95% CI [−9.0 to 0.1]). Conditioning stimulus intensity and test stimulus selection did not influence the CPM effect nor the difference in CPM effects derived from parallel versus sequential designs.

Conclusions

Differences in CPM effects between protocols were minimal or absent. A parallel design may lead to a minimally higher relative CPM effect when using a mechanical test stimulus. The conditioning stimulus intensities assessed in this study and performing two test stimuli did not substantially influence the differences between designs nor the magnitude of the CPM effect.

Fatigue Is Associated With Diminished Cardiovascular Response to Anticipatory Stress in Patients With Coronary Artery Disease

BACKGROUND

Fatigue and psychophysiological reactions to mental stress are known to be problematic in coronary artery disease (CAD) patients. Currently, studies exploring the relationship between fatigue and cardiovascular reactivity to stress are scarce and inconsistent. The current study aimed to investigate the links between cardiovascular response to mental stress and fatigue in CAD patients after acute coronary syndrome (ACS).

METHODS

The cross-sectional study investigated 142 CAD patients (85% males, 52 ± 8 years) within 2-3 weeks after recent myocardial infarction or unstable angina pectoris. Fatigue symptoms were measured using Multidimensional Fatigue Inventory 20-items, while cardiovascular reactivity to stress [i.e., systolic (S) and diastolic (D) blood pressure (ΔBP), and heart rate (ΔHR)] was evaluated during Trier Social Stress Test (TSST). In addition, participants completed psychometric measures, including the Hospital Anxiety and Depression scale and the Type D Scale-14. Multivariable linear regression analyses were completed to evaluate associations between fatigue and cardiovascular response to TSST, while controlling for confounders.

RESULTS

After controlling for baseline levels of cardiovascular measures, age, gender, education, heart failure severity, arterial hypertension, smoking history, use of nitrates, anxiety and depressive symptoms, Type D Personality, perceived task difficulty, and perceived task efforts, cardiovascular reactivity to anticipatory stress was inversely associated with both global fatigue (ΔHR: β = -0.238; p = 0.04) and mental fatigue (ΔSBP: β = -0.244; p = 0.04; ΔHR β = -0.303; p = 0.01) as well as total fatigue (ΔSBP: β = -0.331; p = 0.01; ΔHR: β = -0.324; p = 0.01).

CONCLUSION

In CAD patients after ACS, fatigue was linked with diminished cardiovascular function during anticipation of a mental stress challenge, even after inclusion of possible confounders. Further similar studies exploring other psychophysiological stress responses are warranted.

Blunted Pain Modulation Response to Induced Stress in Women with Fibromyalgia with and without Posttraumatic Stress Disorder Comorbidity: New Evidence of Hypo-Reactivity to Stress in Fibromyalgia?

There is evidence regarding the presence of alterations in both the stress response and the endogenous pain modulation systems of people with fibromyalgia (FM). However, research on pain modulation under induced stress on FM patients is scarce and contradictory. The present study analyzes stress-induced changes in pain and intolerance thresholds among FM patients, examining the possible existence of differences linked to PTSD comorbidity and gaining insights into the role of cardiovascular reactivity. Eighteen women diagnosed with FM and comorbid PTSD (FM + PTSD), 18 women diagnosed with FM and no PTSD (FM-PTSD), and 38 healthy women (HC) were exposed to the Social Stress Test task. Pressure pain thresholds and intolerance thresholds were measured before and during stress induction, and after a recovery period, while systolic blood pressure and heart rate were simultaneously recorded. Overall, while pain thresholds decreased during stress and recovery for HC, no significant changes were observed for women with FM. The intolerance threshold decreased for HC during stress, but was maintained at basal level during recovery. FM-PTSD women exhibited a delayed response, with a drop at recovery. For FM + PTSD, tolerance levels remained unchanged. In addition, cardiovascular reactivity did not seem to explain these results. This performance of the pain modulation system seems to follow the same pattern of hypoactive responsiveness under stressors that has previously been observed in FM patients on the autonomic and neuroendocrine axes. Such a hypoactive pattern may involve a non-adaptive response that may contribute to the development and maintenance of chronic pain.

Effects of Mindfulness-Based Stress Reduction on Experimental Pain Sensitivity and Cortisol Responses in Women With Early Life Abuse: A Randomized Controlled Trial

OBJECTIVE

Early life abuse (ELAb) initiates pathophysiological cascades resulting in long-term maladaptive stress responsivity, hyperalgesia, and an increased risk of psychopathology. Mindfulness-based stress reduction (MBSR) is effective in modifying psychological and somatic symptoms; thus, we predicted that MBSR would be particularly efficacious for women with ELAb.

METHOD

Medically healthy women (mean age = 31 years) with or without a history of early (≤13 years) physical or sexual abuse provided self-report measures and were tested in the laboratory before and after randomization to standard MBSR (n = 52) or social support (SSG) (n = 60) for 8 weeks. The laboratory procedure involved pain testing using the cold pressor and temporal summation of heat pain (indexing central sensitization) procedures, and exposure to the Trier Social Stress Test. Plasma cortisol in response to the experimental protocol was assessed as area under the curve (AUC).

RESULTS

The interventions differentially impacted pain sensitivity and cortisol AUC for women with ELAb, as MBSR increased the temporal summation of heat pain intensity ratings (p = .024) and reduced cortisol AUC (p = .004). For women without ELAb, MBSR decreased cold pressor tolerance (p = .045) and decreased the temporal summation of heat pain intensity ratings relative to SSG (p = .024). Both MBSR and SSG improved depression symptoms and emotion regulation abilities (p values < .001); however, MBSR was associated with greater benefits in describing emotions (p = .008) and impulse control (p = .017) for women with ELAb.

CONCLUSIONS

Women with ELAb benefited from MBSR-specific improvements in central sensitization, mindfulness skills, and emotion regulation abilities. This is the first study to examine the efficacy of MBSR in modifying affective and somatic symptoms based on ELAb status and provides evidence for considering ELAb in tailoring treatment approaches.Trial Registration: ClinicalTrials.gov Identifier: NCT01995916; https://clinicaltrials.gov/ct2/show/NCT01995916.

Collagenase Treatment of Dupuytren's Disease with Minimum 5-Year Follow-Up: Recurrence, Reintervention, and Satisfaction

BACKGROUND

The objective of this study was to determine the rates of patient satisfaction, perceived recurrence of flexion deformity, and additional treatment after collagenase clostridium histolyticum treatment for Dupuytren's contracture at a minimum of 5-year follow-up.

METHODS

A retrospective study was performed of 199 digits in 142 patients who underwent collagenase clostridium histolyticum treatments from April of 2010 to December of 2013 with a minimum of 5-year follow-up. Patients were contacted by telephone regarding perceived recurrence, additional treatment, satisfaction, and willingness to undergo this treatment again.

RESULTS

At an average 7.2-year follow-up, 160 of 199 digits (80 percent) had perceived recurrence, and 105 of 199 digits (53 percent) underwent additional treatment. Average satisfaction was 6.5 on a Likert scale ranging from 1 to 10, and 67 percent would undergo collagenase clostridium histolyticum treatment again. Multivariable logistic regression analysis showed that higher Charlson Comorbidity Index (OR, 0.77; 95 percent CI, 0.63 to 0.93) and isolated metacarpophalangeal joint involvement (OR, 0.53; 95 percent CI, 0.29 to 0.97) were associated with decreased odds of additional treatment, and higher American Society of Anesthesiologists physical status classification (OR, 2.49; 95 percent CI, 1.35 to 4.48) and nonsmoker status (OR, 0.23; 95 percent CI, 0.09 to 0.59) were associated with willingness to undergo the treatment again.

CONCLUSIONS

Patients may be counseled that the long-term perceived recurrence rate of Dupuytren's contractures after collagenase clostridium histolyticum treatment is high, and more than half of patients seek additional treatment. Satisfaction and willingness to undergo collagenase clostridium histolyticum treatment decrease with perceived recurrence.

CLINICAL QUESTION/LEVEL OF EVIDENCE

Therapeutic, III.

Cardiovascular Reactivity to Acute Mental Stress: THE IMPORTANCE OF TYPE D PERSONALITY, TRAIT ANXIETY, AND DEPRESSION SYMPTOMS IN PATIENTS AFTER ACUTE CORONARY SYNDROMES

PURPOSE

Links between psychophysiological reactions to stress stimuli and perceived mental distress, including type D personality, anxiety, and depression, are still under debate. The aim of this study was to examine associations between cardiovascular reactivity to social stress and mental distress in patients after acute coronary syndrome.

METHODS

Patients (n = 116, 86% males, 52 ± 8 yr) with coronary artery disease 2 wk after acute coronary syndrome were evaluated for sociodemographic, clinical characteristics and coronary artery disease risk factors. The Trier Social Stress Test was employed to measure cardiovascular reactions to social stress (systolic and diastolic blood pressure and heart rate). Mental distress assessment included type D personality (Type D Scale), anxiety and depressive symptoms (Hospital Anxiety and Depression Scale), and state and trait anxiety (State-Trait Anxiety Inventory).

RESULTS

Multiple linear regression analysis showed associations between type D personality and lower heart rate during Trier Social Stress Test periods of task instruction (β = -.196, P < .04), preparation time (β = -.232, P < .01), and recovery time (β = -.209, P < .029). Higher trait anxiety was linked with lower heart rate during baseline rest (β = -.287, P < .01), task instruction (β = -.286, P < .01), preparation time (β = -.241, P < .01), and recovery period (β = -.209, P < .05). Depressive symptoms were associated with higher systolic blood pressure during baseline rest (β =.187, P < .05), task instruction (β = .306 P < .01), and free speech (β = .264, P < .05).

CONCLUSIONS

Mental distress was associated with cardiovascular stress reactions independent from possible covariates, suggesting dysregulated psychophysiological reactions to acute stress.

Exercise-induced pain threshold modulation in healthy subjects: a systematic review and meta-analysis

Background

The use of exercise is a potential treatment option to modulate pain (exercise-induced hypoalgesia). The pain threshold (PT) response is a measure of pain sensitivity that may be a useful marker to assess the effect of physical exercise on pain modulation.

Aim

The aim of this systematic review and meta-analysis is to evaluate the PT response to exercise in healthy subjects.

Methods

We searched in MEDLINE, EMBASE, Web of Science, Lilacs, and Scopus using a search strategy with the following search terms: "exercise" OR "physical activity" AND "Pain Threshold" from inception to December 2nd, 2019. As criteria for inclusion of appropriate studies: randomized controlled trials or quasi-experimental studies that enrolled healthy subjects; performed an exercise intervention; assessed PT. Hedge's effect sizes of PT response and their 95% confidence intervals were calculated, and random-effects meta-analyses were performed.

Results

For the final analysis, thirty-six studies were included (n=1326). From this we found a significant and homogenous increase in PT in healthy subjects (ES=0.19, 95% CI= 0.11 to 0.27, I2=7.5%). According to subgroup analysis the effect was higher in studies: with women (ES=0.36); performing strength exercise (ES=0.34), and with moderate intensity (ES=0.27), and no differences by age were found. Confirmed by the meta-regression analysis.

Conclusion

This meta-analysis provides evidence of small to moderate effects of exercise on PT in healthy subjects, being even higher for moderate strength exercise and in women. These results support the idea of modulation of the endogenous pain system due to exercise and highlight the need of clinical translation to chronic pain population.

Effects of smoking on patients with chronic pain: a propensity-weighted analysis on the Collaborative Health Outcomes Information Registry

Tobacco smoking is associated with adverse health effects, and its relationship to pain is complex. The longitudinal effect of smoking on patients attending a tertiary pain management center is not well established. Using the Collaborative Health Outcomes Information Registry of patients attending the Stanford Pain Management Center from 2013 to 2017, we conducted a propensity-weighted analysis to determine independent effects of smoking on patients with chronic pain. We adjusted for covariates including age, sex, body mass index, depression and anxiety history, ethnicity, alcohol use, marital status, disability, and education. We compared smokers and nonsmokers on pain intensity, physical function, sleep, and psychological and mood variables using self-reported NIH PROMIS outcomes. We also conducted a linear mixed-model analysis to determine effect of smoking over time. A total of 12,368 patients completed the CHOIR questionnaire of which 8584 patients had complete data for propensity analysis. Smokers at time of pain consultation reported significantly worse pain intensities, pain interference, pain behaviors, physical functioning, fatigue, sleep-related impairment, sleep disturbance, anger, emotional support, depression, and anxiety symptoms than nonsmokers (all P < 0.001). In mixed-model analysis, smokers tended to have worse pain interference, fatigue, sleep-related impairment, anger, emotional support, and depression over time compared with nonsmokers. Patients with chronic pain who smoke have worse pain, functional, sleep, and psychological and mood outcomes compared with nonsmokers. Smoking also has prognostic importance for poor recovery and improvement over time. Further research is needed on tailored therapies to assist people with chronic pain who smoke and to determine an optimal strategy to facilitate smoking cessation.

Blood Flow Restriction Exercise: Effects of Sex, Cuff Width, and Cuff Pressure on Perceived Lower Body Discomfort

Narrow cuffs cause less discomfort than wide cuffs immediately following elbow flexion exercise in combination with blood flow restriction, possibly due to a balling up effect of the bicep underneath the cuff. In this study, we sought to examine the impact of cuff width, sex, and pressure on perceived discomfort in the quadriceps, following knee extensions. One hundred participants completed three separate experiments. In Experiment 1, we compared participants' discomfort at rest after using a 5 and a 12 cm cuff. In Experiment 2, we compared the discomfort from these two cuffs after four sets of exercise. In Experiment 3, we used the same exercise protocol as in Experiment 2, but we compared the discomfort between a 12 cm cuff inflated to an inappropriate pressure and a 12 cm cuff inflated to the recommended pressure. We found no sex differences in Experiments 1 and 3. In Experiment 1, the narrow cuff had higher discomfort (16 vs 12 AU). In Experiment 2, men reported higher discomfort than women, with no discomfort differences related to cuff width, though narrow cuffs were most preferred. In Experiment 3, cuffs inflated to a pressure intended for narrow cuffs were associated with higher discomfort, and participants preferred to use it less. In summary, we found no strong evidence for discomfort differences due to cuff width. There was some indication that participants preferred narrow cuffs with pressures inflated to the recommended relative pressure. Muscle shape may influence how cuff width affects discomfort.

Neuropeptide and cytokine regulation of pain in the context of substance use disorders

Substance use disorders (SUDs) are frequently accompanied by affective symptoms that promote negative reinforcement mechanisms contributing to SUD maintenance or progression. Despite their widespread use as analgesics, chronic or excessive exposure to alcohol, opioids, and nicotine produces heightened nociceptive sensitivity, termed hyperalgesia. This review focuses on the contributions of neuropeptide (CRF, melanocortin, opioid peptide) and cytokine (IL-1β, TNF-α, chemokine) systems in the development and maintenance of substance-induced hyperalgesia. Few effective therapies exist for either chronic pain or SUD, and the common interaction of these disease states likely complicates their effective treatment. Here we highlight promising new discoveries as well as identify gaps in research that could lead to more effective and even simultaneous treatment of SUDs and co-morbid hyperalgesia symptoms.

A modality-specific dysfunction of pain processing in schizophrenia

Clinical observations showed that schizophrenia (SCZ) patients reported little or no pain under various conditions that are commonly associated with intense painful sensations, leading to a higher risk of morbidity and mortality. However, this phenomenon has received little attention and its underlying neural mechanisms remain unclear. Here, we conducted two experiments combining psychophysics, electroencephalography (EEG), and functional magnetic resonance imaging (fMRI) techniques to investigate neural mechanisms of pain insensitivity in SCZ patients. Specifically, we adopted a stimulus-response paradigm with brief stimuli of different sensory modalities (i.e., nociceptive, non-nociceptive somatosensory, and auditory) to test whether pain insensitivity in SCZ patients is supra-modal or modality-specific, and used EEG and fMRI techniques to clarify its neural mechanisms. We observed that perceived intensities to nociceptive stimuli were significantly smaller in SCZ patients than healthy controls, whereas perceived intensities to non-nociceptive somatosensory and auditory stimuli were not significantly different. The behavioral results were confirmed by stimulus-evoked brain responses sampled by EEG and fMRI techniques, thus verifying the modality-specific nature of the modulation of nociceptive information processing in SCZ patients. Additionally, significant group differences were observed in the spectral power of alpha oscillations in prestimulus EEG and the seed-based functional connectivity in resting-state fMRI (seeds: the thalamus and periaqueductal gray that are key nodes in ascending and descending pain pathways respectively), suggesting a possible contribution of cortical-subcortical dysfunction to the phenomenon. Overall, our study provides insight into the neural mechanisms of pain insensitivity in SCZ and highlights a need for systematic assessments of their pain-related diseases.

Risk factors for liposomal bupivacaine resistance after total hip or knee arthroplasties: a retrospective observational cohort in 237 patients

Purpose

Liposomal bupivacaine demonstrated promise decreasing postoperative pain in total hip and total knee arthroplasty (THA/TKA). Some randomized trials have shown non-superior results; however, confounding variables were not accounted for in such analyses. This study attempts to determine risk factors associated with failure of pain management in patients receiving liposomal bupivacaine.

Methods

Postoperative pain scores were collected following primary or revision arthroplasties between January 2016 and December 2017. Retrospective analysis of institutional total joint quality and outcomes registry was screened and patients undergoing primary or revision arthroplasties who completed a multi-modal pain management including liposomal bupivacaine were included in the study. Patients with a history of infection/deviated from the institutional pain management protocol were excluded.

Results

A total of 237 patients were included for analysis. Younger patients less than 64 years old had significantly higher pain scores between 0 and 12 h and > 24 h. Active smokers had significantly higher pain scores between 0 and 6 h and > 24 h. Patients with a history of opioid use/pain management had significantly higher pain scores at 6-12 h and 24-48 h. Regression analysis indicated risk factors for resistance to liposomal bupivacaine are younger patients less than 64 years old, those undergoing primary THA, and patients with a history of smoking/pain management/opioid use.

Conclusion

We identify risk factors for resistance to liposomal bupivacaine, which include younger age less than 64 years old, history of smoking/pain management/opioid use. Future studies should use these risk factors as exclusion criteria when using liposomal bupivacaine or initiating any randomized trials regarding efficacy.

The association of cardiovascular reactivity during the Trier Social Stress Test with quality of life in coronary artery disease patients

OBJECTIVE

Knowledge of objective psychophysiological stress parameters and its relationship to health-related quality of life (HRQoL) is limited in patients with coronary artery disease (CAD). The aim was to investigate the association of cardiovascular reaction to psychosocial stress with HRQoL in patients with CAD.

METHODS

One-hundred and thirty-six patients (84.6% men, age 52 ± 8) within 2-3 weeks after acute coronary syndromes (ACS) during cardiac rehabilitation were recruited in this cross-sectional study. Patients were evaluated for HRQoL (SF-36 questionnaire), symptoms of anxiety and depression (Hospital Anxiety and Depression scale) and Type D personality (DS14 scale). Trier Social Stress Test (TSST) was employed to evaluate cardiovascular reactivity (systolic and diastolic blood pressure [BP], and heart rate [HR]) to psychosocial stress. Multiple linear regression analyses were performed to test for the associations between cardiovascular reactivity and HRQoL, while controlling for possible confounders.

RESULTS

After controlling for baseline levels of HR, gender, age, NYHA functional class, AH, Type D personality, symptoms of anxiety and depression, use of beta-blockers, and history of smoking, the SF-36 Social functioning scale (β = -0.182; p = .03) and SF-36 Vitality scale (β = -0.203; p = .03) was associated with prolonged HR recovery following stress evoking tasks. No associations were found between HRQoL and BP measures during the TSST.

CONCLUSION

In CAD patients who have experienced ACS, HRQoL was associated with prolonged HR recovery after mental stress, even after controlling for potential confounder. Future studies should investigate the possible role of mediating factors involved in the mechanisms relating cardiovascular stress response and HRQoL.

Widespread pain and pain intensity in patients with early rheumatoid arthritis. A cross-sectional comparison between smokers and non-smokers

AIM

The aim was to investigate if smoking status at time for diagnoses of rheumatoid arthritis was associated with pain intensity or pain spread.

DESIGN

A cross-sectional study conducted in 2012-2013.

METHODS

Seventy-eight patients, of whom 16 were current smokers and 62 never or previous smokers, with newly diagnosed rheumatoid arthritis were assessed as to pain intensity, widespread pain and disease activity.

RESULTS

Of the participants, 56% had unacceptable pain, 77% had spread pain and 28% had chronic widespread pain. There were no differences in pain intensity, widespread pain or chronic widespread pain between smoking status groups. However, there was a positive association between pain intensity and disease activity, r = 0.52.

CONCLUSION

In this study, patients with early rheumatoid arthritis had a high-frequency unacceptable pain and wide spread pain, irrespective of smoking status. However, we cannot exclude that the inflammatory-associated pain overshadowed a possible negative effect of smoking.

Racial differences in presentations and predictors of acute pain after motor vehicle collision

African Americans experience a greater burden of acute pain than non-Hispanic white individuals across of variety of acute medical conditions, but it is unknown whether this is the case after trauma. We evaluated pain, pain-related characteristics (eg, peritraumatic distress), and analgesic treatment in 2 cohorts of individuals (African American [n = 931] and non-Hispanic white [n = 948]) presenting to the emergency department (ED) after a motor vehicle collision. We performed a propensity-matched analysis (n = 796 in each group) to assess racial differences in acute pain in the ED. In multivariable models conducted within the matched sample, race was associated with moderate to severe axial pain (odds ratio [OR] 3.2; 95% confidence interval [CI]: 2.1-5.0, P < 0.001) and higher average numerical rating scale scores (1.3; 95% CI: 1.1-1.6; P < 0.001). After adjustment for pain and other covariates, non-Hispanic white patients were more likely to receive an opioid analgesic in the ED (OR 2.0; 95% CI: 1.4-3.0, P < 0.001) or at discharge (OR 4.9; 95% CI: 3.4-7.1, P < 0.001) and also less likely to receive an NSAID in the ED (OR 0.54; 95% CI: 0.38-0.78; P = 0.001) or at discharge (0.31; 95% CI: 0.43-0.84). Racial differences in the severity of acute posttraumatic pain after a motor vehicle collision are not explained by factors such as socioeconomic status or crash characteristics. Despite a higher burden of acute pain, African Americans were less likely to receive opioid analgesics and more likely to receive NSAIDs. Further work is needed to understand the relationship between pain severity, disparities in analgesic treatment, and longer term outcomes, such as post-motor vehicle collision chronic pain.

The impact of cuff width and biological sex on cuff preference and the perceived discomfort to blood-flow-restricted arm exercise

OBJECTIVE

To investigate the influence of cuff width, sex, and applied pressure on the perceived discomfort associated with blood flow restriction at rest and following exercise.

APPROACH

Experiment 1 (n  =  96) consisted of four sets of biceps exercise to failure with a narrow and wide cuff inflated to the same relative pressure. Experiment 2 (n  =  87) compared two wide cuffs, one of which was inflated to a relative pressure obtained from a narrow cuff. Experiment 3 (n  =  50) compared the discomfort of wide and narrow cuffs at rest. Effects are presented as median δ (95% credible interval).

MAIN RESULTS

There was no sex effect for any variable of interest. In Experiment 1, the narrow cuff resulted in less discomfort than the wide cuff (39.3 versus 42.5; median δ  -0.388 (-0.670, -0.109)). Participants also rated the narrow cuff as more preferable. Experiment 2 found that a wide cuff inflated to a narrow cuffs pressure resulted in greater discomfort than a wide cuff (44 versus 40.9; median δ: 0.420 (0.118, 0.716)). Experiment 3 found no difference between cuff widths.

SIGNIFICANCE

Blood flow restricted exercise with a narrow cuff results in less discomfort than a wider cuff inflated to the same relative pressure. This effect is not observed at rest and suggests that the wide cuff produces a differential environment compared to a narrow cuff when combined with exercise. Additionally, applying a pressure meant for a narrow cuff to a wide cuff augments the applied pressure and subsequent discomfort to blood flow restricted exercise.

Impact of early life adversity on the stress biobehavioral response during nicotine withdrawal

Exposure to early life adversity (ELA) is associated with increased subsequent risk for addiction and relapse. We examined changes in psychobiological responses to stress in dependent smokers and nonsmoking controls and evaluated how history of early adversity may exacerbate acute changes during nicotine withdrawal and acute stress. Smokers were randomly assigned to one of two conditions; 24 h withdrawal (66 smokers) from smoking and all nicotine-containing products or smoking ad libitum (46 smokers) prior to an acute laboratory stress induction session; and 44 nonsmokers provided normal referencing. The laboratory session included a baseline rest, stress and recovery periods. Plasma and saliva samples for the measurement stress hormones and cardiovascular and self-report mood measures were collected multiple times during the session. Multivariate analysis confirmed that all groups showed stress-related increases in negative mood, cardiovascular measures and stress hormones, particularly smokers in the withdrawal condition. Individuals with high ELA showed greater adrenocorticotropic hormone (ACTH), but lower plasma and salivary cortisol levels, than those with low ELA. Cortisol differences were abolished during tobacco withdrawal. These findings demonstrate that ELA moderates the effects of withdrawal on stress-related biobehavioral changes.

The effect of passive heat stress on distress andself-control in male smokers and non-smokers

In the current study, we tested the effects of core body temperature increases (e.g. heat stress) on affect, self-reported physical discomfort, and subsequent self-control in male smokers and nonsmokers using a novel passive heat stress paradigm, within a distress tolerance framework. Twenty-eight men (14 smokers), completed both heat stress and control sessions in randomized order. Results revealed that increases in core body temperature were associated with increased anxiety, irritability, and body discomfort as well as decreased happiness, with stronger effects for smokers. Smokers and nonsmokers both evidenced less self-control during the heat session and did not differ on this measure, nor on a measure of interoceptive sensitivity. The current study indicates that heat stress is a viable method for studying distress tolerance in men, and suggests the value in examining dynamic changes in self-control as a function of distress. Implications will be discussed for distress tolerance in general and smokers in specific.

Cigarette Smoking and Musculoskeletal Pain Severity Among Male and Female Afghanistan/Iraq Era Veterans

Objective

Cigarette smoking and musculoskeletal pain are prevalent among Department of Veterans Affairs (VA) health care system users. These conditions frequently co-occur; however, there is limited empirical information specific to Afghanistan/Iraq era veterans. The present study sought to examine gender differences in the association between cigarette smoking and moderate to severe musculoskeletal pain in US veterans with Afghanistan/Iraq era service.

Methods

A random sample of 5,000 veterans with service after November 11, 2001, participated in a survey assessing health care needs and barriers to care. One thousand ninety veterans completed the survey assessing post-traumatic stress disorder (PTSD) symptoms, depressive symptoms, and current pain severity. Multivariate logistic regression was used to examine the association between gender, cigarette smoking status, and current moderate to severe musculoskeletal pain.

Results

Findings indicated a significant gender by smoking interaction on moderate/severe musculoskeletal pain, adjusting for age, self-reported race/ethnicity and weight status, combat exposure, probable PTSD, depressive symptoms, service-connected injury during deployment, and VA health care service utilization. Deconstruction of the interaction indicated that female veteran smokers, relative to female nonsmokers, had increased odds of endorsing moderate to severe musculoskeletal pain (odds ratio [OR] = 2.73, 95% confidence interval [CI] = 1.16-6.41), whereas this difference was nonsignificant for male veterans (OR = 1.03, 95% CI = 0.69-1.56).

Conclusions

Survey data from Operation Enduring Freedom/Operation Iraqi Freedom veterans suggest an association between current smoking, gender, and moderate to severe musculoskeletal pain. The stronger relationship between smoking and pain in women supports the need for interventional and longitudinal research that can inform gender-based risk factors for pain in veteran cigarette smokers.

Stress and Addiction: When a Robust Stress Response Indicates Resiliency

OBJECTIVE

Stress reactivity research has traditionally focused on the idea that exaggerated responses to stress may have adverse effects on health. Accumulating evidence suggests that attenuated responses to stress and delayed recovery may also be problematic.

METHODS

This review focuses on the role of the stress response of the hypothalamic-pituitary-adrenocortical axis, the endogenous opioid system, and the cardiovascular system in hypertension, pain perception, and addictive behaviors. Results from multiple methods of assessment and stress paradigms conducted in our laboratory over the past two decades are integrated with research from other investigators and with existing theories.

RESULTS

Research indicates that exaggerated biological and physiological responses to stress and attenuated pain perception are associated with hypertension and risk for cardiovascular diseases. This research complements work linking reduced stress responses with enhanced pain sensitivity and discomfort. Multiple studies have also demonstrated that an attenuated stress response is linked to exacerbation of withdrawal symptoms and relapse in nicotine addiction. Evidence indicates important moderators (i.e., sex, personality traits, and early life adversity) and hypothalamic-pituitary-adrenocortical- and endogenous opioid system-related mechanisms in the altered response to stress. I integrate these findings in a conceptual model emphasizing that robust stress responses in the context of addiction and relapse should be considered as a marker of resiliency.

CONCLUSIONS

A blunted stress response may indicate long-term physiological dysregulation that could usher harmful consequences for cardiovascular disease, pain perception, and addictive disorders. The impact of dysregulation is influenced by multiple individual and situational factors that should be considered in evaluating the clinical significance of stress response dysregulation.

Clinical Characteristics and Treatment Patterns Among Patients Diagnosed With Cluster Headache in U.S. Healthcare Claims Data

OBJECTIVE

To characterize demographics, clinical characteristics, and treatment patterns of patients with cluster headache (CH).

BACKGROUND

CH is an uncommon trigeminal autonomic cephalalgia with limited evidence-based treatment options. Patients suffer from extremely painful unilateral headache attacks and autonomic symptoms with episodic and chronic cycles.

DESIGN/METHODS

This retrospective analysis used insurance claims from Truven Health Analytics MarketScan® research databases from 2009 to 2014. Two cohorts were compared: CH patients (with ≥2 CH claims) were propensity score matched with 4 non-headache controls, all with continuous enrollment for 12 months before and after the date of first CH claim or matched period among controls.

RESULTS

CH patients (N = 7589) were mainly male (57.4%) and 35-64 years old (73.2%), with significantly more claims for comorbid conditions vs controls (N = 30,341), including depressive disorders (19.8% vs 10.0%), sleep disturbances (19.7% vs 9.1%), anxiety disorders (19.2% vs 8.7%), and tobacco use disorders (12.8% vs 5.3%), with 2.5 times greater odds of suicidal ideation (all P < .0001). Odds of drug dependence were 3-fold greater among CH patients (OR = 2.8 [95% CI 2.3-3.4, P < .0001]). CH patients reported significantly greater use of prescription medications compared with controls; 25% of CH patients had >12 unique prescription drug claims. Most commonly prescribed drug classes for CH patients included: opiate agonists (41%), corticosteroids (34%), 5HT-1 agonists (32%), antidepressants (31%), NSAIDs (29%), anticonvulsants (28%), calcium antagonists (27%), and benzodiazepines (22%). Only 30.4% of CH patients received recognized CH treatments without opioids during the 12-month post-index period. These patients were less likely to visit emergency departments or need hospitalizations (26.8%) as compared to CH patients with no pharmacy claims for recognized CH treatments or opioids (33.6%; P < .0001).

CONCLUSIONS

The burden of CH is associated with significant co-morbidity, including substance use disorders and suicidal ideation, and treatment patterns indicating low use of recognized CH treatments.

Perinatal Depression, Adverse Life Events, and Hypothalamic-Adrenal-Pituitary Axis Response to Cold Pressor Stress in Latinas: An Exploratory Study

BACKGROUND

Latinas are disproportionately affected by perinatal depression (PND) as well as by adverse life events (ALEs), an independent predictor of PND. Dysregulation of the hypothalamic-pituitary-adrenal (HPA) axis has been seen both in women with PND and with a history of ALEs in non-Latinas. Although some evidence suggests that HPA axis dysregulation may mediate the link between ALEs and PND, this hypothesis has received little attention and there are no studies that have examined these pathways in Latinas. The primary aim of the present study was to explore, in a Latina sample, associations between ALEs, PND, and HPA axis stress reactivity to a physical stressor, the cold pressor test (CPT). The secondary aim was to explore whether HPA axis reactivity and PND were associated with pain sensitivity to the CPT.

METHODS

Thirty-four Latinas were enrolled in their third trimester of pregnancy and interviewed at 4 and 8 weeks postpartum. Depression status was determined using the Edinburgh Postnatal Depression Scale (≥10). At 8 weeks postpartum, 27 women underwent laboratory-induced pain testing using the CPT. Plasma adrenocorticotropic hormone and cortisol were sampled before and after the CPT to generate a stress reactivity score (post-pre). Pain sensitivity and ALEs were also assessed.

RESULTS

At enrollment, 26% of women were depressed, and 18% were depressed at 8 weeks postpartum. Fifty-two percent reported at least one childhood ALE. There was a significant and positive association between any childhood ALE and prenatal depression scores (p = .025). Infant-related ALEs were significantly associated with greater adrenocorticotropic hormone reactivity to the CPT (p = .030). Women with a history of any childhood ALE exhibited a blunted cortisol response to the CPT (p = .045). Women with a history of PND at 4 weeks had greater adrenocorticotropic hormone stress reactivity to the CPT (p = .027). No effects of PND were seen for pain sensitivity measures in response to the CPT, although there was a positive and significant correlation between pain tolerance and cortisol response to the CPT in the whole sample.

CONCLUSIONS

Given the associations between ALEs and PND and their individual effect on HPA axis stress reactivity, future studies on PND should include a larger sample of Latinas to test the mediating effects of HPA axis reactivity on associations between ALEs and PND.

Assessment of pain in adolescents: Influence of gender, smoking status and tobacco abstinence

PURPOSE

We examined sex differences between smokers and nonsmokers in pain threshold, tolerance, and intensity and the effect of pain on cardiovascular measures, withdrawal, and craving during acute smoking abstinence.

METHODS

Ninety-six (53 smokers, 43 nonsmokers) adolescents completed the Cold Pressor Task (CPT) to assess pain responses after minimal (1h) and 42-hour smoking deprivation. Vital signs and craving were assessed before and after CPT completion.

RESULTS

Smokers, compared to nonsmokers, had significantly lower pain tolerance (p<0.01) and pain threshold (p<0.001). Female smokers had significantly lower pain tolerance prior to, and following, 42-hour deprivation compared to male smokers (p's<0.01), male nonsmokers (p's<0.01), and female nonsmokers (p's<0.001), while male smokers demonstrated significantly decreased pain tolerance following 42-hour deprivation (p<0.05). Additionally, during minimal deprivation, at time of hand removal, female smokers had higher pain intensity compared to female nonsmokers (p<0.05) and male smokers (p<0.01). Withdrawal was not significantly correlated with any CPT measures or subjective pain during or following minimal deprivation or acute abstinence. Craving was associated with pain 15s after hand submersion (p=0.007) at 42-hour deprivation.

CONCLUSIONS

Smokers had a lower pain threshold than non-smokers, with female smokers demonstrating lower pain tolerance during minimal deprivation than all comparison groups, and, continuing to have diminished pain tolerance compared to female nonsmokers following 42h of abstinence. Male smokers demonstrated tobacco-deprivation-induced reductions in pain tolerance. Further study of pain-related factors that may contribute to relapse and maintenance of smoking behaviors, and mechanisms of these relationships among adolescent smokers is warranted.

The effects of alcoholism and smoking on advanced cancer patients admitted to an acute supportive/palliative care unit

AIM

The aim of this prospective study was to determine the characteristics and symptom burden of advanced cancer patients with alcoholism problems and smoking, who were referred to an acute palliative/supportive care unit (ASPCU) of a comprehensive cancer center.

METHODS

Patients' characteristics, indications for admission, kind of admission, awareness of prognosis, and anticancer treatments were recorded. The Edmonton Symptom Assessment Scale (ESAS) was used to assess physical and psychological symptoms, and the CAGE questionnaire for the diagnosis of alcoholism. Patients were also divided in three groups: persistent smokers (PS), former smokers (FS), and non-smokers (NS). The Memorial Delirium Assessment Scale (MDAS) was used to assess the cognitive status of patients. Analgesic drugs and their doses at admission and discharge were recorded, as well opioid escalation index during hospital stay.

RESULTS

Three hundred fourteen consecutive cancer patients were surveyed. Forty-seven (14.9%), 143 (45.5%), and 124 (39.5%) subjects were PS-patients, FS-patients, and NS-patients, respectively. Sixteen patients were CAGE-positive. Females were more frequently NS, while males were more frequently FS (p = 0.0005). Statistical differences were also observed in disease awareness among the categories of smoking (p = 0.048). No statistical differences were found in ESAS items, except for drowsiness at T0 in NS-patients. Differences were found in OME and OEI, although the large variability of data did not determined a statistical difference. Higher values of nausea (at T0, p = 0.0005), dyspnea (at T0 and TX, p = 0.08 and 0.023, respectively), and well-being (at TX p = 0.003) were reported in CAGE-positive patients. No correlation was found between CAGE-positive patients and smokers.

CONCLUSION

Although smoking and alcoholism have obvious implications in advanced cancer patients, data remain controversial, as present data did provide limited data to confirm risk factors for advanced cancer patients. Clinical response was not strongly influenced by these risk factors.

Effect of smoking status and nicotine dependence on pain intensity and outcome of treatment in Indian patients with temporomandibular disorders: A longitudinal cohort study

PURPOSE

Evidence regarding the association of smoking with various forms of chronic musculoskeletal pain is vast, but that with temporomandibular disorders (TMD) is scarce.

AIMS

The aims of this study are to evaluate the effect of smoking status (SS) and nicotine dependence (ND) on TMD pain intensity and treatment outcome in an Indian population with TMD.

SUBJECTS AND METHODS

Nine hundred and sixty-two patients with TMD were selected for this longitudinal cohort study. Lifetime SS was evaluated and patients were classified as current smokers (YS), former smokers (FS), or nonsmokers (NS). The Fagerstrom test was used to evaluate the ND of YS. Pain intensity was evaluated using visual analog scale scores. Six months posttreatment, the pain intensity was again recorded. The effect of treatment was evaluated using a global transition outcome measure and categorized as treatment success or failure. A minimum 30% reduction in pain was used as a criterion for categorizing patients as those who had gotten "better." Data obtained from the study were compared using Chi-square tests, paired samples t-tests, and one-way ANOVA tests. The criterion for statistical significance for all analyses was set at P = 0.05.

RESULTS

Among groups of SS, YS showed the maximum pain intensity at baseline and posttreatment. The outcome of treatment was most successful in NS and least in FS. The number of patients who had gotten "better" after treatment was significantly highest in NS. There was no significant difference between groups of ND with respect to pain intensity, treatment outcome, or "better" patients.

CONCLUSIONS

Among Indian patients with TMD, smokers reported significantly greater pain intensity and poorer response to treatment than NS. Pain intensity or treatment outcome was independent of ND.

Pressure and cold pain threshold reference values in a large, young adult, pain-free population

Background and aims

Currently there is a lack of large population studies that have investigated pain sensitivity distributions in healthy pain free people. The aims of this study were: (1) to provide sex-specific reference values of pressure and cold pain thresholds in young pain-free adults; (2) to examine the association of potential correlates of pain sensitivity with pain threshold values.

Methods

This study investigated sex specific pressure and cold pain threshold estimates for young pain free adults aged 21–24 years. A cross-sectional design was utilised using participants (n =617) from the Western Australian Pregnancy Cohort (Raine) Study at the 22-year follow-up. The association of site, sex, height, weight, smoking, health related quality oflife, psychological measures and activity with pain threshold values was examined. Pressure pain threshold (lumbar spine, tibialis anterior, neck and dorsal wrist) and cold pain threshold (dorsal wrist) were assessed using standardised quantitative sensory testing protocols.

Results

Reference values for pressure pain threshold (four body sites) stratified by sex and site, and cold pain threshold (dorsal wrist) stratified by sex are provided. Statistically significant, independent correlates of increased pressure pain sensitivity measures were site (neck, dorsal wrist), sex (female), higher waist-hip ratio and poorer mental health. Statistically significant, independent correlates of increased cold pain sensitivity measures were, sex (female), poorer mental health and smoking.

Conclusions

These data provide the most comprehensive and robust sex specific reference values for pressure pain threshold specific to four body sites and cold pain threshold at the dorsal wrist for young adults aged 21–24 years. Establishing normative values in this young age group is important given that the transition from adolescence to adulthood is a critical temporal period during which trajectories for persistent pain can be established.

Implications

These data will provide an important research resource to enable more accurate profiling and interpretation of pain sensitivity in clinical pain disorders in young adults. The robust and comprehensive data can assist interpretation of future clinical pain studies and provide further insight into the complex associations of pain sensitivity that can be used in future research.

Heightened cold pain and pressure pain sensitivity in young female adults with moderate-to-severe menstrual pain

This study investigated the association between menstrual pain severity and psychophysical measures of cold and pressure pain sensitivity. A cross-sectional design was used with young women (n = 432) from the Western Australian Pregnancy Cohort (Raine) Study. Menstrual pain severity and oral contraception use was obtained from questionnaires at 20 and 22-year follow-ups. A visual analog scale (VAS; range from 0 [none] to 10 [unbearable]) was used to measure menstrual pain severity at both 20 and 22 years over the 3-year period, with 3 groups created: (1) no pain or mild pain (VAS 0-3), (2) at least moderate pain at a minimum of 1 of the 2 time points (hereafter named "mixed)", and (3) severe pain (VAS 8-10). Cold pain sensitivity (dorsal wrist) and pressure pain sensitivity (lumbar spine, upper trapezius, dorsal wrist, and tibialis anterior) were assessed using standardised quantitative sensory testing protocols. Confounding variables included number of musculoskeletal pain sites, oral contraceptive use, smoking, physical activity, body mass index, psychological distress, and sleep. Severe menstrual pain and mixed menstrual pain were positively associated with heightened cold pain sensitivity (distant from menstrual pain referral site) and pressure pain sensitivity (local to menstrual pain referral site). These associations remained significant after adjusting for potential confounding variables including multisite musculoskeletal pain. Our findings suggest peripheral and central neurophysiological mechanisms contributing to heightened pain sensitivity in young women with moderate and severe menstrual pain. These data highlight the need for innovative management approaches to attenuate the negative impact of severe menstrual pain in young women.

Acute analgesic effects of nicotine and tobacco in humans: a meta-analysis

Although animal models have consistently demonstrated acute pain inhibitory effects of nicotine and tobacco, human experimental studies have yielded mixed results. The main goal of this meta-analysis was to quantify the effects of nicotine/tobacco administration on human experimental pain threshold and tolerance ratings. A search of PubMed and PsycINFO online databases identified 13 eligible articles, including k = 21 tests of pain tolerance (N = 393) and k = 15 tests of pain threshold (N = 339). Meta-analytic integration for both threshold and tolerance outcomes revealed that nicotine administered through tobacco smoke and other delivery systems (eg, patch, nasal spray) produced acute analgesic effects that may be characterized as small to medium in magnitude (Hedges g = 0.35, 95% confidence interval = 0.21-0.50). Publication bias-corrected estimates remained significant and indicated that these effects may be closer to small. Sex composition was observed to be a significant moderator, such that pain threshold effects were more robust among samples that included more men than women. These results help to clarify a mixed literature and may ultimately help to inform the treatment of both pain and nicotine dependence. Pain and tobacco smoking are both highly prevalent and comorbid conditions. Current smoking has been associated with more severe chronic pain and physical impairment. Acute nicotine-induced analgesia could make smoking more rewarding and harder to give up. Future research should use dynamic measures of experimental pain reactivity and further explore biopsychosocial mechanisms of action.

Social Support Attenuates Physiological Stress Responses and Experimental Pain Sensitivity to Cold Pressor Pain

BACKGROUND

Social support improves health and has been shown to attenuate stress and pain. The precise characteristics of social support responsible for these effects, however, remain elusive.

PURPOSE

The purpose of this study is to examine the relative efficacy of social support versus a neutral non-verbal social presence to attenuate stress and pain.

METHODS

Seventy-six participants provided pain ratings and task assessments during a cold pressor task (CPT) in one of three conditions: verbal social support, neutral non-support, or alone. Reactivity to the CPT was assessed via cardiovascular measures, cortisol, and subjective ratings.

RESULTS

Participants receiving social support showed attenuated blood pressure, heart rate, and cortisol reactivity, as well as reduced pain ratings, task difficulty, tension, and effort compared to neutral non-support and alone conditions.

CONCLUSIONS

Social support, not the mere presence of another individual, attenuated stress and pain during a CPT. Given the negative health consequences of stress and pain, clinical studies incorporating social support into medical procedures and treatments are warranted.

The Implications of Tobacco Smoking on Acute Postoperative Pain: A Prospective Observational Study

Background. The clinical importance of cigarette smoking on acute postoperative pain perception is not fully understood. Methods. To determine whether smokers who underwent major surgery need more postoperative opiate than do nonsmokers. We prospectively enrolled 407 male and 441 female participants who underwent in-hospital surgery. Current-smokers were compared with nonsmokers and past-smokers about opiate use during the first 72 h after surgery. Results. A greater proportion of males had more smoking history than females. The average age of male current-smokers is smaller than both nonsmokers and past-smokers. The surgical type (upper abdomen, lower abdomen, extremities, spine, and others) and duration of surgery have no differences between current-smokers, past-smokers, and nonsmokers. Statistically, the male current-smokers required more opiate analgesics during the first 72 h following surgery compared with the male nonsmokers and past-smokers; furthermore, the male current-smokers reported higher pain intensity when moving and at rest on day 1 after surgery. Conclusions. In this study, the male current-smokers required more morphine in the first 72 h after surgery than did the nonsmokers and past-smokers. Furthermore, smoking was more prevalent among the males than the females. Health care providers must be aware of the potential for increased narcotic requirements in male current-smokers.