Pack-years of tobacco cigarette smoking as a predictor of spontaneous pain reporting and experimental pain reactivity

Associations between smoking and pain in early recovery in residential substance use treatment-seekers

INTRODUCTION

A growing literature indicates bidirectional associations between pain and tobacco use. Cigarette smokers are at increased risk for chronic pain, and observational and experimental studies indicate that pain increases motivation to smoke. Tobacco use disorder frequently co-occurs with other substance use disorders, which are also associated with chronic pain vulnerability. Despite evidence that pain significantly predicts smoking and relapse, associations between smoking history/trajectory and changes in pain over the course of treatment have not been characterized. The objective of the study was to determine the association between in-treatment smoking trajectory, pack-years (i.e., number of cigarette packs smoked per day multiplied by smoking duration), pain-related interference in daily activities, and pain intensity over the course of residential treatment.

METHODS

In this study, 280 adult smokers in a residential SUD treatment center in North Central Florida completed questionnaires assessing cigarette use, pain intensity, and pain interference at treatment entry and discharge (Mean = 80.3 days, SD = 25.6). Most participants were diagnosed with alcohol use disorder (66.1 %). Opioid (27.9 %) and cannabis use disorders (29.6 %) were also common. Participants were grouped by whether their smoking increased (n = 36), decreased (n = 46), or stayed the same (n = 133) from entry to discharge.

RESULTS

Analyses indicated a positive association between pack-years and pain intensity at both baseline (r = 0.185, p = 0.018) and discharge (r = 0.184, p = 0.019). Smoking trajectory was associated with pack-years, with those decreasing smoking having greater pack-years than those sustaining or increasing use [F(2,136) = 8.62, p < 0.01, η2p = 0.114]. Mixed general linear models indicated pain intensity [F(1,274) = 44.15, p < 0.0001, η2p = 0.138] and interference in day-to-day activities [F(1,276) = 31.79, p < 0.0001, η2p = 0.103] decreased significantly over time. However, there was no main effect of smoking trajectory on pain intensity [F(2,212) = 2.051, p = 0.131, η2p = 0.019] or of smoking trajectory by time interaction [F(2, 212) = 1.228, p = 0.295, η2p = 0.011].

CONCLUSIONS

Overall, findings provide evidence that smoking behavior influences pain within the context of residential substance use treatment. Given that pain is associated with urge to use substances and risk of return to use, more consistent and rigorous assessment of pain and proactive pain management is likely to enhance substance use treatment outcomes among people who smoke.

Association between smoking and central sensitization pain: a web-based cross-sectional study

PURPOSE

This study aimed to investigate whether smoking is an independent risk factor for central sensitization syndrome (CSS) in individuals with pain as measured by the Central Sensitization Inventory (CSI).

METHODS

In 2020, we conducted an Internet survey targeting 2000 ordinary residents of Japan (aged 20-69 years) who had pain symptoms from October to November 2020. A multiple regression analysis was performed on the association between smoking status (nonsmokers and current smokers; Brinkman index) and CSI values. Moreover, compared to nonsmokers, the relative risk (RR) of the CSI cut-off score of 40 points or higher among current smokers was calculated using a modified Poisson regression model. Covariates included age, sex, body mass index, marital status, equivalized income, exercise habits, history of hypertension, history of hyperlipidemia, history of diabetes, pain chronicity, and Pain Catastrophizing Scale score.

RESULTS

This study analyzed 1,822 individuals (1,041 men and 781 women). Among those experiencing pain, current smoking was associated with the increase in CSI values (β = 0.07). The Brinkman index was also significantly associated with the increase in CSI values (β = 0.06). Current smoking also increased the risk of being over the CSI cut-off score, with a relative risk (RR) of 1.29 (95% confidence intervals, 1.04-1.60). Younger age, being women, experiencing chronic pain, and higher pain catastrophizing thinking were also significantly associated with increased CSS severity, independent of smoking status.

CONCLUSION

Smoking is an independent risk factor for CSS. This indicates that smoking may be an important factor in the management of central pain disorders.

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.

Environmental factors and their impact on chronic pain development and maintenance

It is more than recognized and accepted that the environment affects the physiological responses of all living things, from bacteria to superior vertebrates, constituting an important factor in the evolution of all species. Environmental influences range from natural processes such as sunlight, seasons of the year, and rest to complex processes like stress and other mood disorders, infections, and air pollution, being all of them influenced by how each creature deals with them. In this chapter, it will be discussed how some of the environmental elements affect directly or indirectly neuropathic pain, a type of chronic pain caused by a lesion or disease of the somatosensory nervous system. For that, it was considered the edge of knowledge in translational research, thus including data from human and experimental animals as well as the applicability of such findings.

Pain interference among adult dual combustible and electronic tobacco users in terms of perceived barriers for quitting

Electronic cigarette (e-cigarette) use has become increasingly common among combustible cigarette users, and dual use may represent a more severe type of nicotine addiction. Experiencing pain is one prevalent domain that may be important to understand quit processes and behavior among dual users. Although most past research on pain and nicotine/tobacco has focused on combustible cigarette use, initial work on e-cigarette users has found that greater pain severity is associated with higher levels of dependence and negative thinking patterns about e-cigarette use. Yet, there has been no effort to explore the experience of pain among dual users in terms of perceived barriers for quitting combustibles or e-cigarettes. The present study sought to examine pain interference among dual combustible and e-cigarette users in terms of perceived barriers for quitting among 138 (45.9% female; Mage = 35.96 years, SD = 7.16) adult dual users (i.e., users of both combustible cigarette and e-cigarettes). Hierarchical linear regression models indicated that pain interference was significantly associated with both perceived barriers for cessation of combustible cigarettes and perceived barriers for cessation of e-cigarettes. Overall, the present investigation served as an initial evaluation of the role of pain interference in terms of perceived barriers for quitting combustible and e-cigarettes among adult daily dual users. (PsycInfo Database Record (c) 2024 APA, all rights reserved).

Pain-Related Smoking Expectancies and Smoking Behavior Among U.S. Adult Cigarette Smokers with Chronic Pain

BACKGROUND

This study investigated the factor structure of a measure of pain-smoking interrelations and expectancies (pain and smoking inventory (PSI)) and examined associations with risk factors for smoking maintenance among smokers with chronic pain (CP).

METHOD

Participants (n = 504; M age = 46 ± 13 years; 58% female) completed an online survey about health-related factors and smoking characteristics. Data were analyzed using Horn's parallel analysis (PA) and multiple linear regression.

RESULTS

PA indicated that a single-dimension structure was the best fit for the PSI. Our regression model accounted for 34% of the variance in PSI score. The PSI was associated with younger age, higher education, poorer physical functioning, greater pain severity and pain intensity, higher psychological distress, greater nicotine dependence, lower self-efficacy and greater perceived difficulty quitting, and lifetime use of behavioral treatment for quitting smoking.

CONCLUSION

This research is the first step in identifying potential targets for smoking cessation approaches tailored to smokers with CP.

Pleural fluid adenosine deaminase to serum C-reactive protein ratio for diagnosing tuberculous pleural effusion

BACKGROUND

Tuberculous pleural effusion (TPE) and malignant pleural effusion (MPE) may occasionally show similar cytological and biochemical picture including ADA. In such cases, differentiating TPE and MPE is challenging and needs histopathology of pleural tissue which may involve invasive procedures. The present study aims to evaluate the diagnostic accuracy of pleural fluid ADA to serum CRP (ADA/CRP) ratio to discriminate between tuberculous and malignant pleural effusion. In addition, we investigated whether the ratio ADA/CRP adds diagnostic value to ADA.

METHODS

This cross-sectional study was conducted in the National Institute of Diseases of the Chest and Hospital (NIDCH), Mohakhali, Dhaka, from July 2021 to February 2022 on diagnosed patients of TPE and malignant pleural effusion MPE. A receiver operating characteristic curve (ROC) was constructed for identifying TPE. The added value of the ADA/CRP ratio to ADA was evaluated using the net reclassification improvement (NRI) and integrated discrimination improvement (IDI). A value of p < 0.05 was considered statistically significant for all tests.

RESULTS

Fifty-nine patients were enrolled in this study, of which 31 had TPE, and 28 had MPE. Pleural fluid ADA to serum CRP ratio and pleural fluid ADA level was significantly higher in patients with TPE, but there was no significant difference in serum CRP levels between patients with TPE and MPE. At cut off value of > 1.25, pleural fluid ADA to serum CRP ratio had a sensitivity of 93.8%, specificity of 85.2%, and positive and negative predictive values were 88.2% and 92% respectively, in the diagnosis of TPE and area under ROC curve (AUC) was 0.94. The NRI and IDI analyses revealed added diagnostic value of ADA/CRP to ADA.

CONCLUSION

This study shows that the ADA/CRP ratio improves the diagnostic usefulness of ADA for TPE.

A Novel Metric for Predicting Severity of Disease Features in Friedreich's Ataxia

BACKGROUND

Friedreich's ataxia (FRDA), most commonly caused by a GAA triplet repeat (GAA-TR) expansion in intron 1 of the FXN gene, is characterized by deficiency of frataxin protein and clinical features such as progressive ataxia, dysarthria, impaired proprioception and vibration, abolished deep tendon reflexes, Babinski sign, and vision loss in association with non-neurological features such as skeletal anomalies, hearing loss, cardiomyopathy, and diabetes. Pathogenic GAA-TRs range in size from 60 to 1500 triplets and negatively correlate with age of onset. Clinical severity is predicted by a combination of GAA-TR length and disease duration (DD) via multivariable regressions, which cannot typically be used for the small sample sizes in most studies on this rare disease.

OBJECTIVE

We aimed to develop a single metric, which we call "disease burden" (DB), that encompasses both GAA-TR length and DD for predicting disease features of FRDA in small sample sizes.

METHODS

Linear regression and multivariable regression analysis was used to determine correlation coefficients between different disease features of FRDA.

RESULTS

Using large datasets for validation, we found that DB predicts measures of neurological dysfunction in FRDA better than GAA-TR length or DD. Analogous results were found using small datasets.

CONCLUSIONS

FRDA DB is a novel metric of disease severity that has utility in small datasets to demonstrate correlations that would not otherwise be evident with either GAA-TR or DD alone. This is important for discovering new biomarkers, as well as improving the prediction of severity of disease features in FRDA. © 2023 International Parkinson and Movement Disorder Society.

Longitudinal Associations Between Pain and Use of Cigarettes and E-cigarettes in the Population Assessment of Tobacco and Health (PATH) Study

INTRODUCTION

Pain has been implicated in the onset and maintenance of nicotine addiction, and there is initial cross-sectional evidence of covariation between pain and the use of cigarettes and e-cigarettes. The goals of the current study were to: (1)test pain severity as a predictor of initiating co-use of cigarettes and e-cigarettes, (2)examine longitudinal associations between pain and use/co-use of cigarettes and e-cigarettes, (3)generate the first prevalence rate data regarding cigarette and e-cigarette use as a function of pain, and (4)examine gender as a moderator of these associations.

AIMS AND METHODS

Data were drawn from Waves 1-4 of the Population Assessment of Tobacco and Health Study (2013-2018).

RESULTS

Among exclusive cigarette smokers at Wave 1 (n = 7719), pain severity was associated with a greater likelihood of and faster trajectory to initiating co-use of cigarettes and e-cigarettes (ps < .05). A significant pain × gender interaction (p < .05) revealed this prospective relationship was stronger among women. Among adult respondents who provided at least three waves of data (n = 24 255), greater Wave 1 pain severity was positively associated with e-cigarette use, cigarette smoking, and co-use of cigarettes and e-cigarettes at Waves 2, 3, and 4 (ps < .001). At Wave 4 (n = 33 822), adults with moderate or severe pain endorsed rates of e-cigarette and cigarette use almost two times greater versus no or low pain (ps < .001).

CONCLUSIONS

Collectively, these findings provide evidence that pain likely serves as an important candidate risk factor for the initiation and maintenance of cigarette and e-cigarette use.

IMPLICATIONS

This is the first prospective study to show that pain serves as an important risk factor for initiation and maintenance of cigarette and e-cigarette use over time. Weighted prevalence estimates further demonstrated that individuals with moderate or severe pain endorsed rates of cigarette and e-cigarette use and co-use approximately two times greater compared to those with no or low pain. These findings highlight a subpopulation of nicotine users more susceptible to greater healthcare burden, nicotine dependence, and physical impairment. Nicotine users with comorbid pain may benefit from integrated interventions that address pain in the context of cessation.

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.

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.

The Impact of Smoking on the Development and Severity of Chronic Pain

PURPOSE OF REVIEW

The purpose of this review is to examine the impact of smoking and its role on the development of chronic pain and provide a critical review of recent literature.

RECENT FINDINGS

Recent studies demonstrate the bidirectional and dependent relationship between smoking and chronic pain. Those who are in pain have a more difficult time in the cessation of smoking as well as an increased sensitivity to pain during abstinence, lower confidence, and higher relapse rates. The fear of pain and the anxiety and depression that abstinence causes results in a grim outcome for long-term cessation. The dependent nature between chronic pain and smoking is affected by numerous variables. Providers should consider a multiprong approach to treating chronic pain and targeting smoking cessation treatment by providing motivational therapy, nicotine replacement, and medication therapies to prevent relapse, and providing those who are more likely to relapse with a higher level of care.

Effect of central sensitization on dizziness-related symptoms of persistent postural-perceptual dizziness

Background

Persistent postural-perceptual dizziness (PPPD) is a chronic functional dizziness symptom triggered by psychological stress, but its pathophysiology is unknown. Central sensitization is considered the cause of functional diseases, such as medically unexplained symptoms, and is a psychosocially affected condition. However, the association between dizziness symptoms in PPPD and central sensitization remains unclear. Thus, we conducted a cross-sectional study on the relation between dizziness symptoms and central sensitization in PPPD.

Methods

We recruited 61 outpatients with dizziness who met the PPPD diagnostic criteria. In addition to the evaluation of dizziness symptoms using the Dizziness Handicap Inventory, the participants were evaluated using the Hospital Anxiety and Depression Scale, Pittsburgh Sleep Quality Index, and Central Sensitization Inventory (CSI). A CSI score of 40 or higher was defined as central sensitization syndrome (CSS), and the severity of each condition in CSS and non-CSS participants was compared. We also evaluated the association between dizziness symptoms and central sensitization and coexisting symptoms using linear multiple regression analysis.

Results

We analyzed the data of 50 valid responses (valid response rate of 82.0 percent). Compared with the non-CSS group, the CSS group had a higher degree of disability owing to dizziness and a higher rate of complications of anxiety and depression. The regression analysis results showed that the severity of central sensitization was a related factor that could enhance the dizziness symptoms of PPPD.

Conclusions

Central sensitization may affect the dizziness symptoms of PPPD as an exacerbating factor.

A large-scale population-based epidemiological study on the prevalence of central sensitization syndromes in Japan

A cross-sectional study of 21,665 Japanese residents was performed to investigate the prevalence of central sensitization syndromes (CSS). CSS were assessed using the Central Sensitization Inventory (CSI-A). CSS were defined as a CSI-A score of 40 or higher. Age, sex, district, 10 CSS-related diseases (CSI-B), lifestyle, and mental factors were rated in a self-reported survey. The prevalence of CSS and its relationship with potential factors were examined by sex using descriptive and logistic regression models. The prevalence of CSS was 4.2% in all participants and was significantly higher in women (4.9%) than in men (2.7%). Adjusted odds ratios correlated with CSS for an age of 80–97 years versus 60–79 years (2.07 and 2.89), one or more CSI-B diseases (3.58 and 3.51), few sleeping hours (2.18 and 1.98), high perceived stress (5.00 and 4.91), low (2.94 and 2.71) and high (0.45 and 0.66) resilience versus moderate resilience, and exercise habits (0.68 and 0.55) in men and women (all P < 0.05). The relationship between CSS and age 20 and 59 years, ex-smokers, coffee intake, and alcohol intake differed by sex. The prevalence of CSS was estimated to be low in the healthy population. CSS correlated with CSS-related diseases and some positive and negative factors.

Pain and smoking study (PASS): A comparative effectiveness trial of smoking cessation counseling for veterans with chronic pain

Introduction

Smoking is associated with greater pain intensity and pain-related functional interference in people with chronic pain. Interventions that teach smokers with chronic pain how to apply adaptive coping strategies to promote both smoking cessation and pain self-management may be effective.

Methods

The Pain and Smoking Study (PASS) is a randomized clinical trial of a telephone-delivered, cognitive behavioral intervention among Veterans with chronic pain who smoke cigarettes. PASS participants are randomized to a standard telephone counseling intervention that includes five sessions focusing on motivational interviewing, craving and relapse management, rewards, and nicotine replacement therapy versus the same components with the addition of a cognitive behavioral intervention for pain management. Participants are assessed at baseline, 6, and 12 months. The primary outcome is smoking cessation.

Results

The 371 participants are 88% male, a median age of 60 years old (range 24–82), and smoke a median of 15 cigarettes per day. Participants are mainly white (61%), unemployed (70%), 33% had a high school degree or less, and report their overall health as “Fair” (40%) to “Poor” (11%). Overall, pain was moderately high (mean pain intensity in past week = 5.2 (Standard Deviation (SD) = 1.6) and mean pain interference = 5.5 (SD = 2.2)). Pain-related anxiety was high (mean = 47.0 (SD = 22.2)) and self-efficacy was low (mean = 3.8 (SD = 1.6)).

Conclusions

PASS utilizes an innovative smoking and pain intervention to promote smoking cessation among Veterans with chronic pain. Baseline characteristics reflect a socioeconomically vulnerable population with a high burden of mental health comorbidities.

I smoke to cope with pain: patients' perspectives on the link between cigarette smoking and pain

BACKGROUND

For people with chronic pain, cigarette smoking is associated with greater pain intensity and impairment. Researchers have hypothesized a reciprocal relationship in which pain and smoking exacerbate each other, resulting in greater pain and increased smoking. This study aimed to qualitatively examine patient perspectives on this association.

METHODS

A retrospective thematic analysis of smoking cessation counseling notes for 136 veterans in the Pain and Smoking Study, a tailored smoking cessation trial, was conducted. A validated codebook was applied to each counseling note by four independent coders using Atlas.ti (Atlas.ti, Berlin, Germany). Coders participated in a consensus-forming exercise with salient themes validated among the wider research team.

KEY RESULTS

Participants averaged 60 years of age (range 28-77 years) and were 9% female. The median number of cigarettes smoked per day was 15, with a mean pain intensity score in the last week (from 0-10) of 5.1. While not all patients acknowledged a connection between pain and smoking, we found that (1) pain motivates smoking and helps manage pain-related distress, as a coping strategy and through cognitive distraction, and (2) pain motivates smoking but smoking does not offer pain relief. Concerns about managing pain without smoking was identified as a notable barrier to cessation.

CONCLUSION

Many patients with chronic pain who smoke readily identified pain as a motivator of their smoking behavior and are reluctant to quit for this reason. Integrated interventions for smokers with pain should address these perceptions and expectancies and promote uptake of more adaptive self-management strategies for pain.

Pain Status as a Predictor of Smoking Cessation Initiation, Lapse, and Relapse

INTRODUCTION

Pain and cigarette smoking are highly prevalent and frequently co-occurring conditions that interact in the manner of a positive feedback loop. Despite initial evidence that smokers with co-occurring pain may experience greater difficulty quitting, we are unaware of previous research that has tested prospective associations between pain status and the attainment of smoking cessation milestones.

AIMS AND METHODS

This study examined past 2-week pain status as a predictor of cessation milestones among current smokers who were motivated to quit (Sample 1; N = 301) and smokers who recently initiated a cessation attempt (Sample 2; N = 242). Cessation milestones included initiation of a quit attempt and 7-day point prevalence abstinence (PPA; Sample 1), lapse/relapse (Sample 2), and 7-day PPA at 2-month follow-up (both samples). Indirect associations between pain status and cessation milestones via confidence in quitting and nicotine withdrawal were also examined.

RESULTS

Smokers with pain (vs. no pain) were as follows: less likely to initiate a quit attempt and achieve 7-day PPA; more likely to lapse and/or relapse; and less likely to report 7-day PPA at follow-up. Pain status was indirectly associated with latency cessation milestones via confidence in quitting and with latency to lapse via withdrawal severity.

CONCLUSIONS

This study demonstrated that pain status can predict smoking cessation outcomes. Clinical implications include the need to assess pain in the context of quitting and that smokers with co-occurring pain may benefit from tailored/integrated cessation interventions.

IMPLICATIONS

A growing empirical literature indicates that the presence of co-occurring pain probably contributes to the maintenance of cigarette dependence. The current results provide novel evidence that smokers with co-occurring past 2-week pain are less likely to initiate a quit attempt and maintain smoking abstinence than smokers without co-occurring pain. These findings suggest that smokers with pain face unique barriers to quitting and underscore the utility of assessing and addressing pain among all smokers who are planning a smoking cessation attempt.

Prevalence and impact of comorbid chronic pain and cigarette smoking among people living with HIV

Rates of chronic pain and cigarette smoking are each substantially higher among people living with HIV (PLWH) than in the general population. The goal of these analyses was to examine the prevalence and impact of comorbid chronic pain and cigarette smoking among PLWH. Participants included 3289 PLWH (83% male) who were recruited from five HIV clinics. As expected, the prevalence of smoking was higher among PLWH with chronic pain (41.9%), than PLWH without chronic pain (26.6%, p < .0001), and the prevalence of chronic pain was higher among current smokers (32.9%), than among former (23.6%) or never (17%) smokers (ps < .0001). PLWH who endorsed comorbid chronic pain and smoking (vs. nonsmokers without chronic pain) were more likely to report cocaine/crack and cannabis use, be prescribed long-term opioid therapy, and have virologic failure, even after controlling for relevant sociodemographic and substance-related variables (ps < .05). These results contribute to a growing empirical literature indicating that chronic pain and cigarette smoking frequently co-occur, and extend this work to a large sample of PLWH. Indeed, PLWH may benefit from interventions that are tailored to address bidirectional pain-smoking effects in the context of HIV.

Pain intensity, e-cigarette dependence, and cessation-related outcomes: The moderating role of pain-related anxiety

Pain and nicotine dependence are prevalent, co-occurring conditions posited to interact in the manner of a positive feedback loop; however, most research to date has been conducted among tobacco cigarette smokers. Initial evidence suggests that pain is a risk factor for greater e-cigarette dependence, and additional research is needed to examine covariation between pain and e-cigarette use. There is reason to suspect that pain-related anxiety (i.e., the tendency to respond to pain with anxiety or fear) may be associated with greater e-cigarette dependence and difficulty quitting, and that pain intensity and pain-related anxiety may interact to confer greater risk for e-cigarette use. The current study represents the first examination of cross-sectional associations between pain intensity, pain-related anxiety, and e-cigarette dependence, motivation to quit, history of lifetime e-cigarette quit attempts, perceived barriers to cessation, and negative expectancies during abstinence from e-cigarettes. Participants (N = 520 e-cigarette users, 52.1% female, Mage = 34.85) completed an online survey assessing health behaviors. Results indicated that pain-related anxiety was positively associated with e-cigarette dependence and perceived barriers to cessation (ps < 0.05). Pain-related anxiety was found to moderate relations between pain intensity and primary outcomes, such that pain intensity was positively associated with motivation to quit, likelihood of past failed quit attempt, and negative abstinence expectancies among participants who endorsed high (but not moderate or low) levels of pain-related anxiety. Future research would benefit from examining prospective associations between pain-related anxiety, pain intensity, and e-cigarette use/cessation trajectories among individuals with chronic pain.

Smokers with pain are more likely to report use of e-cigarettes and other nicotine products

Pain and tobacco cigarette smoking frequently co-occur, and smokers report using cigarettes to self-medicate pain. Despite the growing popularity of e-cigarettes and alternative nicotine products, no research has examined their use as a function of pain status. The goal of this study was to test cross-sectional relations between the presence of pain and current use of e-cigarettes, lifetime polynicotine use, and lifetime use of individual nicotine products. The sample was comprised of current daily smokers (N = 301) who were recruited to participate in a web-based longitudinal study examining predictors of cessation milestones. Results indicated that smokers who endorsed past-2-week significant pain (vs. no past-2-week pain) were 3 times more likely to endorse current e-cigarette use, reported having used a greater number of nicotine products in their lifetime, and were nearly 3 times more likely to endorse lifetime polynicotine use. In terms of individual products, smokers with pain were approximately 4 times as likely to have tried e-cigarettes and 7 times more likely to have tried cigars. This is the first study to demonstrate that smokers who endorse significant pain are also more likely to endorse use of e-cigarettes and other combustible nicotine products. Future research is needed to examine polynicotine use in relation to pain reporting among more varied samples of smokers and nonsmokers. (PsycInfo Database Record (c) 2020 APA, all rights reserved).

Associations between smoking status and bodily pain in a cross-sectional survey of UK respondents

BACKGROUND

Research indicates that ex- and current smokers report increased levels of bodily pain compared with never smokers. This could be secondary to smoking-related disease or psychological characteristics of smokers, or it could be a neurological or vascular effect of a period of regular smoking.

AIMS

We compared self-reported levels of bodily pain in daily, never daily and former daily smokers stratified by age group and adjusting for a wider range of covariates than has been undertaken to-date, including health status, neuroticism, anxiety and depression.

METHOD

223,537 UK respondents aged 16+ years were surveyed between 2009 and 2013 in the British Broadcasting Corporation (BBC) Lab UK Study. Respondents provided information on bodily pain, smoking status and a range of sociodemographic, health, behavioural and psychological characteristics.

RESULTS

After adjusting for all covariates, in 16-34-year-olds, reported levels of bodily pain in former daily smokers (Badj = 0.72, 95% CI = 0.30, 1.15, p < .001) and daily smokers (Badj = 0.50, 95% CI = 0.18, 0.82, p < .01) were higher than in never daily smokers. Reported levels of bodily pain were also higher in former daily smokers than in never daily smokers in those aged 35-64 (Badj = 1.04, 95% CI = 0.69, 1.38, p < .001) and 65 + years (Badj = 1.65, 95% CI = 0.07, 3.24, p < .05).

CONCLUSIONS

After adjusting for key characteristics, former daily smokers reported higher levels of bodily pain compared with never daily smokers at all ages. This raises the possibility that a period of smoking may have lasting effects on pain experiences.

Prevalence of smoking in adults with spinal cord stimulators: a systematic review and meta-analysis

BACKGROUND

Smoking adversely impacts pain-related outcomes of spinal cord stimulation (SCS). However, the proportion of SCS patients at risk of worse outcomes is limited by an incomplete knowledge of smoking prevalence in this population. Thus, the primary aim of this systematic review is to determine the prevalence of smoking in adults with chronic pain treated with SCS.

METHODS

A comprehensive search of databases from 1 January 1980 to 3 January 2019 was conducted. Eligible study designs included (1) randomized trials; (2) prospective and retrospective cohort studies; and (3) cross-sectional studies. The risk of bias was assessed using a tool specifically developed for prevalence studies. A total of 1619 records were screened, 19 studies met inclusion criteria, and the total number of participants was 10 838.

RESULTS

Thirteen studies had low or moderate risk of bias, and six had a high risk of bias. All 19 studies reported smoking status and the pooled prevalence was 38% (95% CI 30% to 47%). The pooled prevalence in 6 studies of peripheral vascular diseases was 56% (95% CI 42% to 69%), the pooled prevalence of smoking in 11 studies of lumbar spine diagnoses was 28% (95% CI 20% to 36%) and the pooled prevalence in 2 studies of refractory angina was 44% (95% CI 31% to 58%).

CONCLUSIONS

The estimated prevalence of smoking in SCS patients is 2.5 times greater than the general population. Future research should focus on development, testing and deployment of tailored smoking cessation treatments for SCS patients.

Enhancement of Opioid Antinociception by Nicotine

Nicotine can produce antinociception in preclinical pain models; however, the ability of nicotine to augment the antinociceptive effects of opioid agonists has not been investigated. The present experiments were conducted to determine how nicotine modifies the effects of opioid agonists differing in efficacy. Male squirrel monkeys responded for the delivery of milk under a fixed ratio 10 schedule of reinforcement. During the 30-second timeout period following each milk delivery, the subject's tail was immersed in 35, 50, 52, or 55°C water, and the latency to remove the tail was recorded. Dose-response functions for tail-withdrawal latency and operant performance were determined for fentanyl, oxycodone, buprenorphine, and nalbuphine alone and after treatment with nicotine. Excepting nalbuphine, all opioids produced dose-related disruptions in food-maintained responding and increases in tail-withdrawal latency at each water temperature. Nicotine did not exacerbate the behaviorally disruptive effects of the μ-opioids on operant performance but produced a significant mecamylamine-sensitive enhancement of the antinociceptive potency of each opioid. Failure of arecoline to augment the antinociceptive effects of oxycodone and antagonism by mecamylamine suggests this nicotine-induced augmentation of prescription opioid antinociception was nicotinic acetylcholine receptor (nAChR) mediated. This was reflected in leftward shifts in the antinociceptive dose-response curve of each opioid, ranging from 2- to 7-fold increases in the potency of oxycodone across all water temperatures to an approximately 70-fold leftward shift in the antinociceptive dose-response curve of nalbuphine at the lower and intermediate water temperatures. These results suggest that nicotine may enhance μ-opioid antinociceptive effects without concomitantly exacerbating their behaviorally disruptive effects. SIGNIFICANCE STATEMENT: Prescription opioids remain the most effective pain-management pharmacotherapeutics but are limited by their adverse effects. The present results indicate that nicotine enhances antinociceptive effects of various opioid agonists in nonhuman primates without increasing their disruptive effects on operant performance. These results suggest that nicotine might function as an opioid adjuvant for pain management by enabling decreased clinically effective analgesic doses of prescription opioids without exacerbating their adverse behavioral effects.