What is pain: Are cognitive and social features core components?

Association between Socioeconomic Inequalities in Pain and All-cause Mortality in China: Evidence from the China Health and Retirement Longitudinal Study

BACKGROUND

Fewer studies focus on the equality of pain, and the relationship between pain and death is inconclusive. Investigating the distribution of pain and potential mortality risks is crucial for ameliorating painful conditions and devising targeted intervention measures.

OBJECTIVE

Our study aimed to investigate the association between inequalities in pain and all-cause mortality in China.

METHODS

Longitudinal cohort data from the China Health and Retirement Longitudinal Study (CHARLS) 2011-2013 (waves 1, wave 2) were used in this study. Pain was self-reported at baseline, and death information was obtained from the 2013 follow-up survey. The concentration index and its decomposition were used to explain the inequity of pain, and the association between pain and death was analyzed by cox proportional risk model.

RESULTS

A total of 16747 participants were included, with an average age of 59.57±9.82 years old. The prevalence of pain was 32.54% (8196/16747). The main pain type was moderate pain (36.36%), and the common pain locations were waist (19.30%), leg (14.78%), and head (13.44%). We found that the prevalence of pain was concentrated in participant with poor economic status (concentration index: -0.066, 95%CI: -0.078, -0.054), and educational level (36.49%), location (36.87%) and economic status (25.05%) contributed significantly to the inequality of pain. In addition, cox regression found that participants with pain was associated with an increased risk of all-cause mortality (HR=1.30, 95%CI: 1.06, 1.61).

CONCLUSIONS

The prevalence of pain in Chinese adults is concentrated among participants with poor economic conditions, and pain increases the risk of all-cause death. Our results highlight the importance of socioeconomic factors to reduce deaths due to pain inequities by implementing targeted interventions to reduce pain inequities.

CLINICALTRIAL

Psychosocial factors in knee osteoarthritis: Scoping review of evidence and future opportunities

OBJECTIVE

Identify, describe and produce an evidence map of studies investigating psychosocial factors association with, or effect on, clinical outcomes for people with knee osteoarthritis.

METHODS

Scoping review of interventional and observational studies was performed. Medline (Ovid), Embase (Ovid), CINAHL, PsycInfo and Web of Science were searched on the 15th May 2023. Screening, data extraction and analysis was performed by two independent researchers. Extracted information included characteristics of studies plus which psychosocial factors were used to investigate association with, or effect on, clinical outcome(s). Descriptive statistics summarized the study design, temporal trend, geographic distribution, frequency of each psychosocial factor and whether associations/effects were observed.

RESULTS

23,065 records were screened, with 108 studies selected. Eighty-two percent of studies (n = 89/108) were cross-sectional in design. Number of studies increased over time and spanned 28 countries. Most research originated from the Americas region (55 %, 59/108). Twenty-four psychosocial factors (11 psychological, 13 social) were identified. Depression (47 %, n = 48/102) and education (28 %, n = 29/102) were the most frequently reported psychological and social factors, respectively. Psychological factors were often reported to have an association with/effect on pain (81 %, n = 71/88) and physical function (75 %, n = 56/74). Social factors were less frequently reported to have an association with or effect on pain (57 %, n = 46/81) and physical function (50 %, n = 18/36).

CONCLUSION

Psychosocial factors are often associated with clinical outcomes for people with knee osteoarthritis. High-quality longitudinal studies examining a wide range of psychosocial factors across diverse cultural and geographical settings are key to continue informing the development of biopsychosocial models of care.

Effect of photobiomodulation therapy on pain perception during anesthetic puncture of dental local anesthesia: A systematic review

BACKGROUND

Local anesthetic puncture is often related to the experience of pain. This study aimed to systematically analyze the literature on changes in pain perception during the anesthetic puncture of dental local anesthesia after Photobiomodulation Therapy (PBMT).

MATERIAL AND METHODS

An electronic search was performed in eight primary databases (Embase, LILACS, BBO, LIVIVO, MedLine via PubMed, SciELO, Scopus, and Web of Science) and three additional ones (EASY, Google Scholar, and OATD) to partially capture the "gray literature". The PICO strategy was used to identify randomized clinical trials evaluating the analgesic effect of PBMT in the anesthetic puncture site of dental local anesthesia compared to placebo or control groups, without restrictions on publication language and year. Two reviewers extracted the data and assessed the individual risk of bias of the eligible studies using the Cochrane Collaboration Risk of Bias Tool version 2.0.

RESULTS

The electronic search found 3,485 records, of which eight met the eligibility criteria and were included in the qualitative synthesis. The studies were published from 2011 to 2022. None of the included studies had a low risk of bias. PBMT groups showed no significant difference in pain scores compared to placebo and control groups of most studies.

CONCLUSION

Based on a low to very low certainty of evidence, PBMT seems to have no effect on pain perception during anesthetic puncture in patients undergoing dental local anesthesia.

Association of Neighborhood Characteristics and Chronic Pain in Children and Adolescents in the United States

OBJECTIVE

To determine the associations between neighborhood characteristics and chronic pain during childhood and adolescence in the United States, 2020-2021.

METHODS

Cross-sectional analysis of the 2020 and 2021 National Survey of Children's Health. National Survey of Children's Health grouped parents' responses to questions about neighborhood characteristics into 5 categories: neighborhood support, neighborhood safety, school support, neighborhood amenities, and the presence of detracting neighborhood elements. Chronic pain was defined as parents reporting their children had "frequent or chronic difficulty with repeated or chronic physical pain, including headache or other back or body pain during the past 12 months." Multivariable Poisson regression analyses estimated associations between neighborhood characteristics and chronic pain, adjusted for sociodemographic characteristics.

RESULTS

The sample contained 55,387 children (6 to 17 years), weighted to represent 44 million nationally. Children had significantly increased rates of chronic pain if they lived in neighborhoods that were unsupportive, unsafe, had unsafe schools, fewer amenities, and greater numbers of detracting elements ( P <0.0001). After adjusting for covariates, children had significantly increased chronic pain if they lived in neighborhoods that were not supportive (adjusted prevalence rate ratio=1.7 (95% CI: 1.5-1.9, P <0.0001), with similar patterns observed for living in neighborhoods characterized as not safe, that did not have safe schools, with fewer amenities, and/or more detracting elements.

DISCUSSION

Disadvantageous neighborhood characteristics are associated with pediatric chronic pain prevalence. Future research should investigate the underlying mechanisms of this association and guide neighborhood interventions aimed at preventing and decreasing childhood chronic pain and its associated burdens.

Pilot RCT comparing low-dose naltrexone, gabapentin and placebo to reduce pain among people with HIV with alcohol problems

BACKGROUND

To estimate the effects on pain of two medications (low-dose naltrexone and gabapentin) compared to placebo among people with HIV (PWH) with heavy alcohol use and chronic pain.

METHODS

We conducted a pilot, randomized, double-blinded, 3-arm study of PWH with chronic pain and past-year heavy alcohol use in 2021. Participants were recruited in St. Petersburg, Russia, and randomized to receive daily low-dose naltrexone (4.5mg), gabapentin (up to 1800mg), or placebo. The two primary outcomes were change in self-reported pain severity and pain interference measured with the Brief Pain Inventory from baseline to 8 weeks.

RESULTS

Participants (N = 45, 15 in each arm) had the following baseline characteristics: 64% male; age 41 years (SD±7); mean 2 (SD±4) heavy drinking days in the past month and mean pain severity and interference were 3.2 (SD±1) and 3.0 (SD±2), respectively. Pain severity decreased for all three arms. Mean differences in change in pain severity for gabapentin vs. placebo, and naltrexone vs. placebo were -0.27 (95% confidence interval [CI] -1.76, 1.23; p = 0.73) and 0.88 (95% CI -0.7, 2.46; p = 0.55), respectively. Pain interference decreased for all three arms. Mean differences in change in pain interference for gabapentin vs. placebo, and naltrexone vs. placebo was 0.16 (95% CI -1.38, 1.71; p = 0.83) and 0.40 (95% CI -1.18, 1.99; p = 0.83), respectively.

CONCLUSION

Neither gabapentin nor low-dose naltrexone appeared to improve pain more than placebo among PWH with chronic pain and past-year heavy alcohol use.

CLINICAL TRIAL REGISTRATION

ClinicalTrials.gov (NCT4052139).

Unraveling Catechol-O-Methyltransferase rs4680 SNP's Role in Patients' Response to Tramadol and Its Adverse Effects: A Pharmacogenetics Insight into Postoperative Pain Management

Effective postoperative pain management is essential for patient well-being and an efficient healthcare system. Variations in the Catechol O-Methyltransferase (COMT) gene, specifically rs4680, play a crucial role in pain perception and opioid response. This study seeks to elucidate the impact of rs4680 polymorphism on tramadol efficacy and adverse reactions in post-surgical patients. We performed an uncontrolled cohort pharmacogenetics study in which participants underwent postoperative tramadol administration. The frequencies of rs4680 alleles were determined and the association between rs4680 genotypes and the efficacy of tramadol analgesic as pain relief, measured by the Numeric Rating Scale (NRS), was analyzed. Secondary outcomes included tramadol-induced sedation levels, opioid-induced nausea and vomiting, and other adverse effects of tramadol. Data analysis, using IBM SPSS Statistics 23, focused on pain and side effect differences across genotypes, with statistical significance set to p ≤ 0.05. The COMT (rs4680) genotype distribution exhibited a 'G' allele frequency of 41.5% and an 'A' allele frequency of 58.5%, with the AA genotype present in 44% of individuals, adhering to the Hardy-Weinberg equilibrium (p = 0.788). Patients with the AA genotype reported lower pain scores post-tramadol administration across all times examined (p < 0.001), but also experienced statistically significant (p < 0.001) higher incidences of tramadol-induced nausea, vomiting, and sedation. However, GG genotype individuals experienced poor pain relief from tramadol, requiring more supplemental analgesia. These significant findings underscore the critical role of COMT rs4680 polymorphism in response to tramadol and the necessity of a personalized approach to postoperative pain management.

Lifetime ostracism experiences and mechanisms of pain

One social mechanism by which marginalization is enacted is via ostracism. Recent research has demonstrated ostracism's impact on physical health, but little is known about the relationship between accumulated lifetime experiences of ostracism and pain. Despite recent calls for added attention to social modulation of pain and social indicators of pain disparities, the impact of specific social factors on pain-including those of ostracism-are not well understood. Results of laboratory studies on the effects of acute ostracism experiences on pain sensitivity have been mixed. However, these studies have not considered lived and repeated experiences of ostracism, and primarily included single static measures of pain sensitivity. Additionally, inclusion and representation of the relationship between ostracism experiences and pain among people with minoritized identities are lacking in the current literature. In this study, we explored accumulated lifetime experiences of ostracism as a potential contributing factor to enhanced pain and one social mechanism by which societal inequity may create and maintain inequity in pain. We extracted measures of lifetime experiences of ostracism from six studies focused on social factors and (non-chronic) pain conducted between 2016 and 2020 (n = 505 adults). To retain and examine diversity within the sample, we used moderation and within-group analyses. Results indicate that greater experiences of lifetime ostracism are associated with lower cold pain tolerance, but not other pain measures, in the whole sample. Moderation and within-group analyses reveal opposing patterns of results between populations included in the extant literature (White participants, convenience samples) and those under-represented in the scientific literature (racialized groups, community samples). This study provides an example of a diversity science approach to examining social indicators of pain, illustrates the limited generalizability of previous studies on ostracism and pain, and highlights the need for increased representation and inclusion to understand mechanisms of pain and inequity.