Gender role affects experimental pain responses: a systematic review with meta-analysis

Incidence and Risk Factors of Chronic Postoperative Pain in Same-day Surgery: A Prospective Cohort Study

BACKGROUND

The amount of same-day surgery has increased markedly worldwide in recent decades, but there remains limited evidence on chronic postsurgical pain in this setting.

METHODS

This study assessed pain 90 days after ambulatory surgery in an international, multicenter prospective cohort study of patients at least 45 yr old with comorbidities or at least 65 yr old. Pain was assessed using the Brief Pain Inventory. Chronic postsurgical pain was defined as a change of more than 1 point in self-rated average pain at the surgical site between baseline and 90 days, and moderate to severe chronic postsurgical pain was defined as a score greater than 4 in self-rated average pain at the surgical site at 90 days. Risk factors for chronic postsurgical pain were identified using multivariable logistic regression.

RESULTS

Between November 2021 and January 2023, a total of 2,054 participants were included, and chronic postsurgical pain occurred in 12% of participants, of whom 93.1% had new chronic pain at the surgical site (i.e., participants without pain before surgery). Moderate to severe chronic postsurgical pain occurred in 9% of overall participants. Factors associated with chronic postsurgical pain were active smoking (odds ratio, 1.82; 95% CI, 1.20 to 2.76), orthopedic surgery (odds ratio, 4.7; 95% CI, 2.24 to 9.7), plastic surgery (odds ratio, 4.3; 95% CI, 1.97 to 9.2), breast surgery (odds ratio, 2.74; 95% CI, 1.29 to 5.8), vascular surgery (odds ratio, 2.71; 95% CI, 1.09 to 6.7), and ethnicity (i.e., for Hispanic/Latino ethnicity, odds ratio, 3.41; 95% CI, 1.68 to 6.9 and for First Nations/native persons, odds ratio, 4.0; 95% CI, 1.05 to 15.4).

CONCLUSIONS

Persistent postsurgical pain after same-day surgery is common, is usually moderate to severe in nature, and occurs mostly in patients without chronic pain before surgery.

EDITOR’S PERSPECTIVE

Associations of Gender Role and Pain in Musculoskeletal Disorders: A Mixed-Methods Systematic Review

Previous studies have investigated the association of gender roles with pain outcomes in healthy individuals. However, little is known about this association in those with musculoskeletal (MSK) disorders. Therefore, this mixed-methods systematic review aimed to investigate the association of sociocultural gender roles on pain outcomes in adults with MSK disorders. Literature from Medline, CINAHL, Web of Science, and Embase was reviewed from inception to February 2023. Eligibility criteria included studies of adults with an MSK pain disorder that explored the relationship between gender roles and pain for all primary qualitative and quantitative study designs. Exclusion criteria were grey literature, review articles, case studies, and conference proceedings. Risk of bias was assessed via the Quality Appraisal for Diverse Studies for quantitative studies and the McMaster Quality Appraisal Tool for qualitative studies. Eleven studies were included, nine qualitative, and two quantitative with a total of 540 participants (19.6% women, 80.4% men) with various MSK disorders. The convergent integrated approach was used to synthesize data from the qualitative and quantitative studies resulting in three themes and seven subthemes. Our findings identified differences in the way individuals explained the cause of their pain, were treated for their pain in a social and systemic context, and in describing the effect pain had on their lives based on gender roles. There is a need for pain management to evolve to acknowledge the individual pain experience through exploration of an individual's gender identity and roles. PERSPECTIVE: This article demonstrates that gender roles have a multidimensional influence on the pain experience in those with musculoskeletal disorders. These findings support the development of gender-sensitive, patient-centered approaches to pain management, acknowledging each individual's important roles and identities.

A control study on pain characteristics and influencing factors in patients with depressive disorders-based on a 5-year follow-up report from the epidemiological survey of mental disorders in Shandong Province, China

BACKGROUND

This study extends from the 2015 Shandong Province Epidemiological Survey of Mental Disorders in adults aged 18 and above. Over five years, it investigates pain characteristics and influencing factors in individuals with depressive disorders in Shandong Province.

METHODS

The study encompasses 871 individuals who met DSM-IV criteria for depressive disorders in 2015. Using 1:1:1 matching by gender, age, and residence, 825 non-afflicted individuals were selected as high-risk controls, and 825 screening-negative individuals became low-risk controls. A follow-up study in 2020 involved 1848 participants. Survey tools included a general information questionnaire, General Health Questionnaire-12 (GHQ-12), SCID-I/P, Global Pain Scale (GPS), Quality of Life Questionnaire (QLQ), PSQI, MoCA, and clinical data questionnaire.

RESULTS

GPS scores in the current depressive group were higher than in non-current depressive group (Z = 14.36, P < 0.01). GPS scores in study group exceeded those in high-risk and low-risk control groups (H = 93.71, P < 0.01). GPS scores in non-remission group were higher than in the remission group (Z = 8.90, P < 0.01). Regression analysis revealed positive correlations between GPS scores and physical illnesses, current depression, incumbency, GHQ-12 total score, and PSQI total score. Negative correlations were observed with QLQ total score and MoCA total score.

LIMITATIONS

The study could not assess pain during the 2015 survey, limiting controlled pain analysis before and after five years.

CONCLUSION

Depression sufferers may experience prolonged heightened pain, potentially relieved when depression subsides. Individual pain is influenced by depression, physical illnesses, sleep quality, quality of life, cognitive function, gender, residence, and occupation.

Exploring the association of gender role expectations of pain and measures of pain sensitization in people with knee osteoarthritis: A cross-sectional study

OBJECTIVES

First, we explored the association between Gender Role Expectations of Pain (GREP), and psychophysical measures of sensitization in people with knee osteoarthritis (OA). Second, we explored whether the association differed by level of GREP items (high vs low scores).

DESIGN

We conducted secondary analyses of a cohort study. Those who were (i) age of ≥40, English or French speaking, ii) diagnosed with knee OA using American College of Rheumatology criteria and iii) consulting with an orthopedic surgeon were included. GREP items pertaining to pain sensitivity and pain endurance of the typical man or woman were rated by males and females respectively. Psychophysical tests consisted of pressure pain thresholds (PPTs), Temporal Summation (TS), and Conditioned Pain Modulation (CPM). Multiple linear regression models for males and females were run with GREP scores (independent variables) and psychophysical tests (dependent variables). Next models stratified on the median split of GREP scores were run. Models were adjusted for age, BMI, pain catastrophizing, anxio-depressive symptoms, and radiographic severity.

RESULTS

280 participants (57% females; age (SD): 63.9 (9.6) and BMI (SD): 31.3 (8.40)) were included. GREP pain sensitivity scores in males were associated with CPM values (β: 95% CI: 0.09 (0.01 to 0.17)). Males with low GREP pain sensitivity or pain endurance had very small to small positive associations with PPT and CPM values.

CONCLUSION

This first exploration of gendered pain sensitivity and pain endurance by males and females has small and clinically unimportant associations with measures of pain sensitization requiring further validation.

The effect of experimental emotion induction on experimental pain: a systematic review and meta-analysis

ABSTRACT

The idea that emotions can influence pain is generally recognized. However, a synthesis of the numerous individual experimental studies on this subject is lacking. The aim of the present systematic review and meta-analysis was to synthesize the existing evidence on the effect of experimental emotion induction on experimental pain in nonclinical adults. PsycInfo and PubMed were searched up until April 10, 2023, for studies assessing differences in self-reported pain between emotion induction groups and/or control groups or between conditions within group. Risk of bias was assessed for the individual studies. The literature search yielded 78 relevant records of 71 independent studies. When compared with control conditions, the pooled results revealed a statistically significant pain-attenuating effect of positive emotion induction (between-group: Hedges g = -0.48, 95% CI: -0.72; -0.25, K = 9; within-group: g = -0.24, 95% CI: -0.32; -0.15, K = 40), and a statistically significant pain-exacerbating effect of negative emotion induction in within-group analyses but not between-group analyses (between-group: g = -0.29, 95% CI: -0.66; 0.07, K = 10; within-group: g = 0.14, 95% CI: 0.06; 0.23, K = 39). Bayesian meta-analysis provided strong support for an effect of positive emotion induction but weak support for an effect of negative emotion induction. Taken together, the findings indicate a pain-attenuating effect of positive emotion induction, while the findings for negative emotion induction are less clear. The findings are discussed with reference to theoretical work emphasizing the role of motivational systems and distraction for pain. Limitations include considerable heterogeneity across studies limiting the generalizability of the findings.

Outcomes of Pain Management Among Postoperative Patients: A Cross-sectional Study

PURPOSE

Postoperative pain management has always been a significant challenge for both hospital staff and surgical patients. Determination of pain management outcomes among surgically treated patients may help develop pain management strategies, improve health services that would yield better outcomes, and increase patient satisfaction. This study aimed to assess the outcomes of pain management among postoperative patients.

DESIGN

The study was a descriptive cross-sectional study.

METHODS

The research was performed on postoperative patients at two university hospitals in North Cyprus from July to September 2019. The study sample consisted of 90 patients from both hospitals. The Turkish Version of the revised American Pain Society Patient Outcome Questionnaire (APS-POQ-R-TR) was used for data collection. The Strengthening the Reporting of Observational Studies in Epidemiology (STROBE) checklist was used to report the present study.

FINDINGS

This study showed that the overall mean for pain severity and the worst pain experienced by patients after 24 hours was slightly higher than medium. Examination of interference of the pain with functions demonstrated that patients experienced problems with physical activities and sleeping. The most experienced side effects were nausea and drowsiness, and the most common emotions were anxiety and helplessness during the postsurgery period. The satisfaction rate of the patients with postoperative pain management was relatively high.

CONCLUSIONS

A holistic approach with evidence-based practices is crucial for adequate postoperative pain management. The recommendations include the development of individual pain outcome strategies to improve overall satisfaction with pain management among postoperative patients.

A developmental framework for understanding the influence of sex and gender on health: Pediatric pain as an exemplar

Sex differences are a robust finding in many areas of adult health, including cardiovascular disease, psychiatric disorders, and chronic pain. However, many sex differences are not consistently observed until after the onset of puberty. This has led to the hypothesis that hormones are primary contributors to sex differences in health outcomes, largely ignoring the relative contributions of early developmental influences, emerging psychosocial factors, gender, and the interaction between these variables. In this paper, we argue that a comprehensive understanding of sex and gender contributions to health outcomes should start as early as conception and take an iterative biopsychosocial-developmental perspective that considers intersecting social positions. We present a conceptual framework, informed by a review of the literature in basic, clinical, and social science that captures how critical developmental stages for both sex and gender can affect children's health and longer-term outcomes. The literature on pediatric chronic pain is used as a worked example of how the framework can be applied to understanding different chronic conditions.

Challenges with embedding an integrated sex and gender perspective into pain research: Recommendations and opportunities

The focus of this article, within this BBI horizons special issue, is on sex, gender, and pain. We summarise what is currently known about sex- and gender-related variations in pain, exploring intersectional biological and psychosocial mechanisms, and highlight gaps in knowledge and understanding. Five key challenges with the exploration of sex and gender in pain research are presented, relating to: conceptual imprecision, research bias, limitations with binary descriptions, integrating sex and gender, and timely adoption/implementation of good research practice. Guidance on how to overcome such challenges is provided. Despite clear evidence for sex and gender differences in pain, there are conceptual and methodological barriers to overcome. Innovation in methods and approach can help develop more effective and tailored treatment approaches for men, women, boys, girls, and gender-diverse people.

Gender-based differential management of acute low back pain in the emergency department: A survey based on a clinical vignette

BACKGROUND

Women may receive suboptimal pain management compared with men, and this disparity might be related to gender stereotypes.

OBJECTIVES

To assess the influence of patient gender on the management of acute low back pain.

DESIGN

We assessed pain management by 231 physicians using an online clinical vignette describing a consultation for acute low back pain in a female or male patient. The vignette was followed by a questionnaire that assessed physicians' management decisions and their gender stereotypes.

METHODS

We created an online clinical vignette presenting a patient with acute low back pain and assessed the influence of a patient's gender on pain management. We investigated gender-related stereotyping regarding pain care by emergency physicians using the Gender Role Expectation of Pain questionnaire.

RESULTS

Both male and female physicians tended to consider that a typical man was more sensitive to pain, had less pain endurance, and was more willing to report pain than a typical woman. These stereotypes did not translate into significant differences in pain management between men and women. However, women tended to be referred less often for imaging examinations than men and were also prescribed lower doses of ibuprofen and opioids. The physician's gender had a modest influence on management decisions, female physicians being more likely to prescribe ancillary examinations.

CONCLUSION

We observed gender stereotypes among physicians. Our findings support the hypothesis that social characteristics attributed to men and women influence pain management. Prospective clinical studies are needed to provide a deeper understanding of gender stereotypes and their impact on clinical management.

The Importance of Gender-Sensitive Health Care in the Context of Pain, Emergency and Vaccination: A Narrative Review

So far, health care has been insufficiently organized in a gender-sensitive way, which makes the promotion of care that meets the needs of women and men equally emerge as a relevant public health problem. The aim of this narrative review was to outline the need for more gender-sensitive medical care in the context of pain, emergency care and vaccinations. In this narrative review, a selective search was performed in Pubmed, and the databases of the World Health Organization (WHO), the European Institute for Gender Equality and the German Federal Ministry of Health were searched. Study data indicate that there are differences between men and women with regard to the ability to bear pain. On the other hand, socially constructed role expectations in pain and the communication of these are also relevant. Studies indicate that women receive adequate pain medication less often than men with a comparable pain score. Furthermore, study results indicate that the female gender is associated with an increased risk of inadequate emergency care. In terms of vaccine provision, women are less likely than men to utilize or gain access to vaccination services, and there are gender-sensitive differences in vaccine efficacy and safety. Sensitization in teaching, research and care is needed to mitigate gender-specific health inequalities.

Sex differences in adverse events following seasonal influenza vaccines: a meta-analysis of randomised controlled trials

BACKGROUND

Despite being a vaccine-preventable disease, influenza remains a major public health threat with vaccine safety concerns reducing vaccine acceptability. Immune responses to vaccines and adverse events may differ between males and females, but most studies do not report results by sex. Using data from clinical trials, we explored sex differences in adverse events following seasonal influenza vaccines.

METHODS

We obtained data for phase III randomised controlled trials identified through a systematic review and clinical trials registries, and performed a two-stage meta-analysis. Risk ratios (RR) and 95% confidence intervals (95% CI) comparing solicited reactions in females versus males were pooled using the Mantel-Haenszel method and a random-effects model. We used the ROBINS-I tool to assess risk of bias and the I2 statistic for heterogeneity. Main analysis was stratified by age: 18-64 years and ≥65 years.

RESULTS

The dataset for this analysis included 34 343 adults from 18 studies (12 with individual-level data and 6 with aggregate data). There was a higher risk of injection site reactions in females compared with males for both younger and older participants, with RRs of 1.29 (95% CI 1.21 to 1.37) and 1.43 (95% CI 1.28 to 1.60), respectively. Higher risk in females was also observed for systemic reactions, with RRs of 1.25 (95% CI 1.20 to 1.31) and 1.27 (95% CI 1.20 to 1.34) for younger and older participants, respectively. We also observed elevated risks of severe reactions in females, with a higher RR in younger versus older participants for systemic reactions (RRs 2.12 and 1.48, p=0.03, I2=79.7%). RRs were not found to vary between quadrivalent and trivalent vaccines.

CONCLUSION

This meta-analysis suggested a higher risk of solicited reactions following influenza vaccines for females compared with males, irrespective of age and vaccine type. Transparent communication of this risk could increase the trust in vaccines and limit vaccine hesitancy. Future studies should report results stratified by sex and explore the role of gender in the occurrence of adverse events.

Influence of Sex on Early Axial Spondyloarthritis: A Six-Year Longitudinal Analysis From a Large National Cohort

OBJECTIVE

The objective was to determine sex differences in disease outcomes in recent axial spondyloarthritis (SpA) over time.

METHODS

We analyzed the first 6 years of follow-up of the prospective French multicenter DESIR cohort. Patients analyzed had <3 years of disease, were naive to disease-modifying antirheumatic drugs, and fulfilled the Assessment of SpondyloArthritis international Society classification criteria for axial SpA. Disease activity (Ankylosing Spondylitis Disease Activity Score [ASDAS] using the C-reactive protein [CRP] level), patient global assessment (PtGA), CRP level, and radiographic sacroiliitis were compared between men and women (self-reported sex) by linear and logistic mixed-effects models. Models were created for trajectories of disease activity over 6 years in men and women, using k-means.

RESULTS

Of 494 patients analyzed (mean ± SD age 31.9 ± 7.5 years, symptoms duration 20.7 ± 11.7 months), 50.4% were men. Over 6 years of follow-up, both men and women showed clear improvements in ASDAS-CRP, PtGA, and CRP level. Women had higher ASDAS-CRP and PtGA over time compared to men (both P < 0.0001) with overall similar CRP levels (P = 0.089), whereas structural damage increased more in men (P < 0.0001). One-third of both men (33%) and women (34%) belonged to persistent high/very high disease activity trajectories, but ASDAS-CRP was globally higher in women in these trajectories.

CONCLUSION

In early axial SpA, clinical outcomes (disease activity and symptoms) were worse in women than men over 6 years of follow-up, whereas CRP was similar and structural damage was more frequent in men. Although similarly distributed, disease activity scores were higher in women in high/very high disease activity trajectories. Sex appears to be an important contextual factor in axial SpA.

Differing Effects of Nociception and Pain Memory on Isometric Muscle Strength in Participants With and Without a History of Injury: A Quasi-Experimental Study

OBJECTIVE

The goals of this study are to establish whether mechanical pressure pain, short-term memory recall of a painful stimulus, or long-term memory of a previous painful lower limb injury alters isometric muscle strength and whether there was a difference in responses between participants with and without a previous history of injury.

DESIGN

Fifty-nine pain-free participants (29 with previous injury and 30 without) participated in this study. Tibialis anterior isometric muscle strength was compared pre- and post-noxious mechanical stimulus with instructions to recall pain (short- and long-term).

RESULTS

Short- and long-term pain recall produced a significant reduction in muscle strength (short-term: F (1,57) = 160.472, P < 0.001; long-term: F (1,57) = 128.899, P < 0.001). A greater decrease was experienced with short- and long-term pain memory than exposure to mechanical pain (mechanical pain: -14.8% or -32.98 kg, 95% confidence interval [CI], -41.57 to -24.19; short-term: -24.1% or -52.70 kg, 95% CI = -60.98 to -44.34; long-term: -20.3% or -44.63 kg, 95% CI = -52.77 to -36.95). There was no significant difference in responses associated with an injury history.

CONCLUSIONS

Findings suggest that recalled pain memory can impact motor responses and calls attention to the role of past injury history in the rehabilitation process.

The intersection of biological sex and gender in adverse events following seasonal influenza vaccination in older adults

BACKGROUND

Women/females report more adverse events (AE) following immunization than men/males for many vaccines, including the influenza and COVID-19 vaccines. This discrepancy is often dismissed as a reporting bias, yet the relative contributions of biological sex and gender are poorly understood. We investigated the roles of sex and gender in the rate of AE following administration of the high-dose seasonal influenza vaccine to older adults (≥ 75 years) using an AE questionnaire administered 5-8 days post-vaccination. Participant sex (male or female) was determined by self-report and a gender score questionnaire was used to assign participants to one of four gender categories (feminine, masculine, androgynous, or undifferentiated). Sex steroid hormones and inflammatory cytokines were measured in plasma samples collected prior to vaccination to generate hypotheses as to the biological mechanism underpinning the AE reported.

RESULTS

A total of 423 vaccines were administered to 173 participants over four influenza seasons (2019-22) and gender data were available for 339 of these vaccinations (2020-22). At least one AE was reported following 105 vaccinations (25%), by 23 males and 82 females. The majority of AE occurred at the site of injection, were mild, and transient. The odds of experiencing an AE were 3-fold greater in females than males and decreased with age to a greater extent in females than males. The effects of gender, however, were not statistically significant, supporting a central role of biological sex in the occurrence of AE. In males, estradiol was significantly associated with IL-6 and with the probability of experiencing an AE. Both associations were absent in females, suggesting a sex-specific effect of estradiol on the occurrence of AE that supports the finding of a biological sex difference.

CONCLUSIONS

These data support a larger role for biological sex than for gender in the occurrence of AE following influenza vaccination in older adults and provide an initial investigation of hormonal mechanisms that may mediate this sex difference. This study highlights the complexities of measuring gender and the importance of assessing AE separately for males and females to better understand how vaccination strategies can be tailored to different subsets of the population.

The Relationship between Nociceptive Detection Thresholds and Pressure- and Electrical Pain Thresholds: An Explorative Study in Rheumatoid Arthritis Patients

Recently, methods have been developed enabling the characterization of the nociceptive function at the detection threshold level by measuring nociceptive detection thresholds (NDTs), rather than at the level of the pain threshold via pain threshold (PT) measurements. Both NDT and PT measurements aim to characterize (parts of) the nociceptive system. To date it is unclear if, and if so to what extent, the two outcomes relate to one another. In this study, the primary aim is to explore the relationship between the two measures in patients with rheumatoid arthritis (RA). As secondary aim, we explore differences in NDT between these RA patients with age- and sex-matched healthy controls (HC) from a readily existing dataset. In total 46 RA patients have been recruited, whereby the pressure- (PPT; bilaterally at two locations) and electrical (EPT) pain threshold were evaluated, as well as the NDTs. Significant, positive correlations were found between the EPT and PPT (R=0.54-0.60), but not with the NDTs (R≤0.25). As compared to HC, higher NDTs were found in the RA group. As the presence of a statistically significant weak relationship can only be evaluated using a larger sample size, our results indicate that there is no moderate or stronger relation between PT and NDT outcomes. This implicates that the two outcomes are not strongly driven by the same (nociceptive) mechanism(s). Future research into NDTs and what factors and/or mechanisms affect the outcome, could yield relevant insights into how to use and interpret the results of this relatively new method.Clinical Relevance - The evaluation of nociceptive detection thresholds, in isolation or together with conventionally evaluated pain thresholds, might provide valuable and complementary insights into nociceptive (dis)function in man.

Preference of musculoskeletal pain treatment in middle-aged and elderly chinese people: a machine learning analysis of the China health and retirement longitudinal study

BACKGROUND

Musculoskeletal pain is a major cause of physical disability, associated with huge socioeconomic burden. Patient preference for treatment is an important factor contributing to the choice of treatment strategies. However, effective measurements for evaluating the ongoing management of musculoskeletal pain are lacking. To help improve clinical decision making, it's important to estimate the current state of musculoskeletal pain management and analyze the contribution of patient treatment preference.

METHODS

A nationally representative sample for the Chinese population was derived from the China Health and Retirement Longitudinal Study (CHARLS). Information on the patients' demographic characteristics, socioeconomic status, other health-related behavior, as well as history on musculoskeletal pain and treatment data were obtained. The data was used to estimate the status of musculoskeletal pain treatment in China in the year 2018. Univariate analysis and multivariate analysis were used to find the effect factors of treatment preference. XGBoost model and Shapley Additive exPlanations (SHAP) method were performed to analyze the contribution of each variable to different treatment preferences.

RESULTS

Among 18,814 respondents, 10,346 respondents suffered from musculoskeletal pain. Approximately 50% of musculoskeletal pain patients preferred modern medicine, while about 20% chose traditional Chinese medicine and another 15% chose acupuncture or massage therapy. Differing preferences for musculoskeletal pain treatment was related to the respondents' gender, age, place of residence, education level, insurance status, and health-related behavior such as smoking and drinking. Compared with upper or lower limb pain, neck pain and lower back pain were more likely to make respondents choose massage therapy (P < 0.05). A greater number of pain sites was associated with an increasing preference for respondents to seek medical care for musculoskeletal pain (P < 0.05), while different pain sites did not affect treatment preference.

CONCLUSION

Factors including gender, age, socioeconomic status, and health-related behavior may have potential effects on people' s choice of treatment for musculoskeletal pain. The information derived from this study may be useful for helping to inform clinical decisions for orthopedic surgeons when devising treatment strategies for musculoskeletal pain.

Sex differences in pain expressed by patients across diverse disease states: individual patient data meta-analysis of 33,957 participants in 10 randomized controlled trials

ABSTRACT

The experience of pain is determined by many factors and has a significant impact on quality of life. This study aimed to determine sex differences in pain prevalence and intensity reported by participants with diverse disease states in several large international clinical trials. Individual participant data meta-analysis was conducted using EuroQol-5 Dimension (EQ-5D) questionnaire pain data from randomised controlled trials published between January 2000 and January 2020 and undertaken by investigators at the George Institute for Global Health. Proportional odds logistic regression models, comparing pain scores between females and males and fitted with adjustments for age and randomized treatment, were pooled in a random-effects meta-analysis. In 10 trials involving 33,957 participants (38% females) with EQ-5D pain score data, the mean age ranged between 50 and 74. Pain was reported more frequently by females than males (47% vs 37%; P < 0.001). Females also reported greater levels of pain than males (adjusted odds ratio 1.41, 95% CI 1.24-1.61; P < 0.001). In stratified analyses, there were differences in pain by disease group (P for heterogeneity <0.001), but not by age group or region of recruitment. Females were more likely to report pain, and at a higher level, compared with males across diverse diseases, all ages, and geographical regions. This study reinforces the importance of reporting sex-disaggregated analysis to identify similarities and differences between females and males that reflect variable biology and may affect disease profiles and have implications for management.

The intersection of biological sex and gender in adverse events following seasonal influenza vaccination in older adults

Background Women/females report more adverse events (AE) following immunization than men/males for many vaccines, including the influenza and COVID-19 vaccines. This discrepancy is often dismissed as a reporting bias, yet the relative contributions of biological sex and gender are poorly understood. We investigated the roles of sex and gender in the rate of AE following administration of the high-dose seasonal influenza vaccine to older adults (≥ 75 years) using an AE questionnaire administered 5-8 days post-vaccination. Participant sex (male or female) was determined by self-report and a gender score questionnaire was used to assign participants to one of four gender categories (feminine, masculine, androgynous, or undifferentiated). Sex steroid hormones and inflammatory cytokines were measured in plasma samples collected prior to vaccination to elucidate a possible biological mechanism for the AE reported. Results A total of 423 vaccines were administered to 173 participants over four influenza seasons (2019-22) and gender data were available for 339 of these vaccinations (2020-22). At least one AE was reported following 105 vaccinations (25%), by 23 males and 82 females. The majority of AE occurred at the site of injection, were mild, and transient. The odds of experiencing an AE were 3-fold greater in females than males and decreased with age to a greater extent in females than males. The effects of gender, however, were not statistically significant, supporting a central role of biological sex in the occurrence of AE. In males, estradiol was significantly associated with IL-6 and with the probability of experiencing an AE. Both associations were absent in females, suggesting a sex-specific effect of estradiol on the occurrence of AE that supports the finding of a biological sex difference. Conclusions These data support a larger role for biological sex than for gender in the occurrence of AE following influenza vaccination in older adults and provide an initial investigation of hormonal mechanisms that may mediate this sex difference. This study highlights the complexities of measuring gender and the importance of assessing AE separately for males and females to better understand how vaccination strategies can be tailored to different subsets of the population.

Are people good prognosticators of their own pain? An exploration of the relationship between sex-specific pain beliefs and clinical pain evaluation

BACKGROUND

Under-explored to date are the interacting influences of patient sex on multi-modal evaluation techniques that tap different domains of the pain experience.

OBJECTIVES

The primary aim of Study 1 was to explore the accuracy of sex-specific personal pain beliefs in relation to quantitative pain indicators within sexes, and the secondary objective was to compare the accuracy of sex-specific personal pain beliefs in relation to quantitative pain indicators between sexes. The primary objective of Study 2 was to explore the accuracy of sex-specific personal pain beliefs and self-rated pain severity within sexes, and the secondary objective was to compare sex-specific personal pain beliefs and pain severity ratings between sexes.

METHODS

A cross-sectional analysis on two datasets was performed (Study 1, n = 50; Study 2, n = 111). For both studies, independent samples t-tests were used to identify differences in clinical pain evaluations based on sex-specific pain beliefs. Receiver Operating Characteristic (ROC) curves were used to compare the predictive accuracy of males and females clinical pain evaluations based on their ability to handle pain.

RESULTS

There were no statistically significant differences in clinical pain evaluations based on self-rated pain beliefs in either study. In Study 2, males were descriptively more accurate predictors of their clinical pain evaluations than were females, though none of the between sex comparisons were statistically significant.

CONCLUSION

This work highlights the importance of considering all available clinical pain evaluations as one technique is unlikely to represent the patients pain experience.

Is Lethality Different between Males and Females? Clinical and Gender Differences in Inpatient Suicide Attempters

According to the gender paradox in suicidology, an important sex difference has been reported with a preponderance of females in nonfatal suicidal behavior and a preponderance of males in completed suicide. Furthermore, females and males present different risk factors for suicide. The present study explored possible clinical differences between male and female psychiatric inpatients who had recently attempted suicide. The study included 177 adult inpatients hospitalized following a suicide attempt at the University Psychiatric Clinic, Sant'Andrea Hospital, Sapienza University of Rome. Clinical features assessed included psychiatric diagnosis, method and lethality of suicide attempts using the Risk/Rescue Rating Scale, the history of suicide attempts, age at onset of psychiatric illness, the presence of substance or alcohol use, and the length of stay. The results found that males and females differed in the method used for the suicide attempt, the scores for risk and rescue, and the length of hospitalization post-suicide attempt. In conclusion, identifying gender characteristics of patients at higher risk of suicide is important for implementing specific suicide prevention strategies and reducing the risk of future suicidal behavior in psychiatric inpatients.

Effectiveness of combined extracorporeal shock-wave therapy and hyaluronic acid injections for patients with shoulder pain due to rotator cuff tendinopathy: a person-centered approach with a focus on gender differences to treatment response

Background

Rotator cuff (RC) tendinopathy is a common shoulder pain condition. Extracorporeal shockwave therapy (ESWT) and hyaluronic acid peritendinous injection are viable treatment options for RC tendinopathy.

The aim of this study is to evaluate the response in two different therapeutic rehabilitative approaches, the combined treatment ESWT plus hyaluronic acid injections (E + Hy) compared to ESWT alone (ESWT-al), in a cohort of patients with RC tendinopathy according to gender differences.

Methods

This is a retrospective longitudinal cohort study of patients with painful RC tendinopathy. Patients that had received a clinical evaluation, a shoulder ultra sound examination, as well as the Shoulder Pain and Disability Index (SPADI) questionnaire, and the Numerical Rating Scale (NRS) for pain at baseline, 1-month (T1) and 2-month follow-ups (T2) were included.

Results

Medical records of 53 patients were analyzed. In the comparison between baseline to T1 and similarly from baseline to T2, a statistically significant reduction has been reported in the NRS (p < 0.001) and in the SPADI (p < 0.001) in the entire study group. At T1, patients in the E + Hy compared to ESWT-al group, showed a slight but statistically significant reductions in both NRS and SPADI score, while these changes were more evident at T2 (p < 0.001). Interestingly, a gender dimorphism in NRS and in SPADI was found, with female patients that apparently responded better to the combined E + Hy compared to ESWT-al approach.

Conclusion

This retrospective cohort study suggests that the combination of ESWT plus HyA injections seems to be more effective than ESWT alone in RC tendinopathy in both genders. Moreover, in ESWT alone treatment, male patients reported better outcomes compared to females. However, further randomized controlled trials should be structured to confirm and enforce these conclusions.

Supplementary Information

The online version contains supplementary material available at 10.1186/s12891-022-05819-3.

Sex and gender differences in pain

Chronic pain affects 20% of adults and is one of the leading causes of disability worldwide. Women and girls are disproportionally affected by chronic pain. About half of chronic pain conditions are more common in women, with only 20% having a higher prevalence in men. There are also sex and gender differences in acute pain sensitivity. Pain is a subjective experience made up of sensory, cognitive, and emotional components. Consequently, there are multiple dimensions through which sex and gender can influence the pain experience. Historically, most preclinical pain research was conducted exclusively in male animals. However, recent studies that included females have revealed significant sex differences in the physiological mechanisms underlying pain, including sex specific involvement of different genes and proteins as well as distinct interactions between hormones and the immune system that influence the transmission of pain signals. Human neuroimaging has revealed sex and gender differences in the neural circuitry associated with pain, including sex specific brain alterations in chronic pain conditions. Clinical pain research suggests that gender can affect how an individual contextualizes and copes with pain. Gender may also influence the susceptibility to develop chronic pain. Sex and gender biases can impact how pain is perceived and treated clinically. Furthermore, the efficacy and side effects associated with different pain treatments can vary according to sex and gender. Therefore, preclinical and clinical research must include sex and gender analyses to understand basic mechanisms of pain and its relief, and to develop personalized pain treatment.

Personal influencing factors for pressure pain threshold in healthy people: A systematic review and meta-analysis

All studies that investigated personal factors influencing pressure pain threshold (PPT) in healthy people were synthesized. Data was summarized, and risk of bias (RoB) and level of evidence were determined. Results were pooled per influencing factor, grouped by body region and included in meta-analyses. Fifty-four studies were eligible. Five had low, nine moderate, and 40 high RoB. Following meta-analyses, a strong conclusion was found for the influence of scapular position, a moderate for the influence of gender, and a weak for the influence of age (shoulder/arm region) and blood pressure on PPT. In addition, body mass index, gender (leg region), alcohol consumption and pain vigilance may not influence PPT. Based on qualitative summary, depression and menopause may not influence PPT. For other variables there was only preliminary or conflicting evidence. However, caution is advised, since the majority of included studies showed a high RoB and several were not eligible to include in meta-analyses. Heterogeneity was high in the performed meta-analyses, and most conclusions were weak. More standardized research is necessary.

Adverse childhood experiences and bodily pain at 10 years of age: Findings from the Generation XXI cohort

BACKGROUND

Youth and young adults with pain conditions report having a history of adverse childhood experiences (ACEs) more frequently than their healthy peers. The relationship between ACEs and pain before adolescence in population-based settings is not extensively researched.

OBJECTIVE

To examine the association between the history of ACEs and bodily pain at 10 years of age.

PARTICIPANTS AND SETTING

Cross-sectional analysis of 4738 participants of Generation XXI population-based birth cohort, recruited in 2005-06 in Porto, Portugal.

METHODS

Study includes self-reported data on ACEs exposures and bodily pain (pain presence, sites, and intensity a week prior to the interview). Adjusted odds ratios (AOR) and 95% confidence intervals (CI) were obtained from binary and multinomial logistic regression analyses to estimate the likelihood of various pain features according to the extent of exposure to ACEs (i.e., 0 ACEs, 1-3 ACEs, 4-5 ACEs, and ≥ 6 ACEs).

RESULTS

Prevalence of pain, multisite, and high-intensity pain a week prior to the interview increased with increasing exposure to ACEs. After controlling for sociodemographic characteristics, children who had experienced ≥6 ACEs were more likely to report pain [AOR 3.18 (95% CI 2.19, 4.74)], multisite pain [AOR 2.45 (95% CI 1.37, 4.40)], and high-intensity pain [AOR 4.27 (95% CI 2.56, 7.12)] compared with children with no ACEs.

CONCLUSIONS

A dose-response association was observed between the cumulative number of ACEs and reports of pain in 10-year-old children, suggesting that embodiment of ACEs starts as early as childhood and that pain related to ACEs begins earlier than previously reported.

Factors Influencing Pain Response Following Patient Education and Supervised Exercise in Male and Female Subjects With Hip Osteoarthritis

OBJECTIVE

To understand factors associated with pain intensity responder status following nonsurgical hip osteoarthritis (OA) intervention, according to sex.

METHODS

Data were from individuals with hip OA participating in the Danish Good Life With Osteoarthritis in Denmark 8-week education and exercise program. The following factors were recorded at program entry: age; education; mental well-being; comorbidities; body mass index; symptoms in hip, knee, and low back; and program-specific factors including education sessions, former participant lectures, and supervised exercise sessions. Pain intensity was recorded at baseline and at month 3 (post-program) on a 0-100-mm visual analog scale. Response was defined as pain intensity improvement of ≥30% from baseline to post-program. Logistic regression was used and conducted separately in male and female subjects.

RESULTS

The sample included 791 men and 2,253 women. Female subjects had a mean baseline pain score of 47.2 of 100 (95% confidence interval [95% CI] 46.4-48.1) and male subjects had a score of 41.7 (95% CI 40.3-43.1). By post-program, the proportion of pain responders was 50.4% among women and 45.8% among men (difference P = 0.025). Among women, program-specific factors (attending former participant lectures and more supervised exercise sessions) were positively associated with pain response, as were better mental well-being and fewer comorbidities, while symptoms in other joints/sites were associated with a decreased likelihood of response. Among men, program-specific factors were not associated with response, while better mental well-being and fewer comorbidities were associated with being a responder.

CONCLUSION

Findings suggest that the influence of some factors on pain response differ for male and female subjects and point to a potential need for targeted approaches for men and women who may require different key messages/approaches from health care providers.

Volunteers' concerns about facial neuromuscular electrical stimulation

Facial neuromuscular electrical stimulation (NMES) is the application of an electrical current to the skin to induce muscle contractions and has enormous potential for basic research and clinical intervention in psychology and neuroscience. Because the technique remains largely unknown, and the prospect of receiving electricity to the face can be daunting, willingness to receive facial NMES is likely to be low and gender differences might exist in the amount of concern for the sensation of pain and skin burns. We investigated these questions in 182 healthy participants. The likelihood of taking part (LOTP) in a hypothetical facial NMES study was measured both before and after presenting a detailed vignette about facial NMES including its risks. Results showed that LOTP was generally high and that participants remained more likely to participate than not to, despite a decrease in LOTP after the detailed vignette. LOTP was significantly predicted by participants' previous knowledge about electrical stimulation and their tendency not to worry about the sensations of pain, and it was inversely related to concerns for burns and loss of muscle control. Fear of pain was also inversely related to LOTP, but its effect was mediated by the other concerns. We conclude that willingness to receive facial NMES is generally high across individuals in the studied age range (18-45) and that it is particularly important to reassure participants about facial NMES safety regarding burns and loss of muscle control. The findings are relevant for scholars considering using facial NMES in the laboratory.

Intravenous ketorolac versus morphine in children presenting with suspected appendicitis: a pilot single-centre non-inferiority randomised controlled trial

OBJECTIVES

Despite a lack of evidence demonstrating superiority to non-steroidal anti-inflammatory drugs, like ketorolac, that are associated with lower risk of harms, opioids remain the most prescribed analgesic for acute abdominal pain. In this pilot trial, we will assess the feasibility of a definitive trial comparing ketorolac with morphine in children with suspected appendicitis. We hypothesise that our study will be feasible based on a 40% consent rate.

METHODS AND ANALYSIS

A single-centre, non-inferiority, blinded (participant, clinician, investigators and outcome assessors), double-dummy randomised controlled trial of children aged 6-17 years presenting to a paediatric emergency department with ≤5 days of moderate to severe abdominal pain (≥5 on a Verbal Numerical Rating Scale) and are investigated for appendicitis. We will use variable randomised blocks of 4-6 and allocate participants in 1:1 ratio to receive either intravenous (IV) ketorolac 0.5 mg/kg+IV morphine placebo or IV morphine 0.1 mg/kg+IV ketorolac placebo. Analgesic co-intervention will be limited to acetaminophen (commonly used as first-line therapy). Participants in both groups will be allowed rescue therapy (morphine 0.5 mg/kg) within 60 min of our intervention. Our primary feasibility outcome is the proportion of eligible patients approached who provide informed consent and are enrolled in our trial. Our threshold for feasibility will be to achieve a ≥40% consent rate, and we will enrol 100 participants into our pilot trial.

ETHICS AND DISSEMINATION

Our study has received full approval by the Hamilton integrated Research Ethics Board. We will disseminate our study findings at national and international paediatric research conferences to garner interest and engage sites for a future multicentre definitive trial.

TRIAL REGISTRATION

NCT04528563, Pre-results.

Motor Learning in Response to Different Experimental Pain Models Among Healthy Individuals: A Systematic Review

Learning new movement patterns is a normal part of daily life, but of critical importance in both sport and rehabilitation. A major question is how different sensory signals are integrated together to give rise to motor adaptation and learning. More specifically, there is growing evidence that pain can give rise to alterations in the learning process. Despite a number of studies investigating the role of pain on the learning process, there is still no systematic review to summarize and critically assess investigations regarding this topic in the literature. Here in this systematic review, we summarize and critically evaluate studies that examined the influence of experimental pain on motor learning. Seventeen studies that exclusively assessed the effect of experimental pain models on motor learning among healthy human individuals were included for this systematic review, carried out based on the preferred reporting items for systematic reviews and meta-analyses (PRISMA) statement. The results of the review revealed there is no consensus regarding the effect of pain on the skill learning acquisition and retention. However, several studies demonstrated that participants who experienced pain continued to express a changed motor strategy to perform a motor task even 1 week after training under the pain condition. The results highlight a need for further studies in this area of research, and specifically to investigate whether pain has different effects on motor learning depending on the type of motor task.

Interviewer effects in a survey examining pain intensity and pain interference in nursing home residents

Introduction

Face-to-face surveys are applied frequently when conducting research in older populations. Interviewers play a decisive role in data quality, may affect measurement and influence results. This study uses survey data about pain in nursing home residents and analyses, whether affiliation-of-interviewer (internal vs. external to nursing home) and gender-of-interviewer affect residents’ responses in terms of interviewer variance and systematically varying pain reports.

Methods

Overall, 258 nursing home residents with up to moderate cognitive impairment were examined by 61 interviewers about pain intensity and interference applying the Brief Pain Inventory. Interviewer variance was measured using intra-interviewer correlation coefficients (ρ). Two-factorial covariance analysis was applied to analyse whether pain intensity and interference scores differ by interviewer characteristics.

Results

Interviewer heterogeneity accounts for almost one quarter of total variance on average. Interviewer variance is higher for internal and male interviewers than for external and female interviewers. Covariance analyses show significant effects of interviewer characteristics on pain reports. Average pain intensity and interference scores vary considerably by interviewer gender and affiliation. Highest pain intensity was reported towards female internal and male external interviewers; highest pain interference was reported towards male external interviewers.

Conclusion

Residents’ answers substantially differ in relation to who is assessing pain. There is a risk of imprecise and biased survey estimates on sensitive topics like pain in nursing homes. Interviewer gender and affiliation seem to evoke gender-specific and status-related expectations and attributions which influence residents’ response process. Interviewer effects pose a considerable threat to survey data quality in institutionalised older populations.

Effects of transcutaneous electrical nerve stimulation (TENS) in people with knee osteoarthritis: A systematic review and meta-analysis

OBJECTIVE

To evaluate the effects of Transcutaneous Electric Nerve Stimulation (TENS) on pain, function, walking ability and stiffness in people with Knee osteoarthritis (KOA).

DESIGN

Systematic review and meta-analysis of randomized controlled trials.

METHODS

We searched MEDLINE, EMBASE, PubMed, Cochrane Central Register of Controlled Trials, Physiotherapy Evidence Database (PEDro), clinicaltrials.gov and Web of Science (last search November 2021) for randomized controlled trials. The Cochrane Risk of Bias Tool was used for the included studies, and Grading of Recommendations, Assessment, Development, and Evaluations (GRADE) was used to interpret the certainty of results. Standardized Mean Differences (SMDs) and 95% confidence interval (CI) were calculated for meta-analysis.

RESULTS

Twenty-nine studies were found (1398 people, age range 54-85, 74% are female) and fourteen were included in this review. Intervention duration was divided as short term (immediately after intervention), medium term (<four weeks) and long term (≥ four weeks). Active TENS showed greater improvement in Visual Analogue Scale (VAS) than sham TENS.Combining TENS with other interventions produced superior outcomes compared with other interventions for VAS in all the terms. In the meanwhile, TENS combined with other interventions was superior to other interventions for the pain subgroup of Western Ontario and McMaster Universities Arthritis Index in the medium term and long term. TENS combined with other interventions was superior to other interventions for function in the medium term and long term.

CONCLUSION

TENS could significantly relieve pain, decrease dysfunction and improve walking ability in people with KOA, but it is not effective for stiffness.

Randomized cross-over evaluation of investigator gender on pain thresholds in healthy volunteers

Background and aims: This randomized cross-over study in healthy volunteers was designed primarily to evaluate the potential impact of investigator gender on electrical pain threshold (EPT) and corresponding pain intensity levels, and secondly to evaluate potential differences in those interventions between female and male study participants. Methods: Forty adult volunteers (22 females) were included. An electrical stimulation device was used to determine EPT levels (in pain magnitude scores) in series of three in each study participant - once by a female, and once by a male investigator - according to a predefined cross-over design schedule. Corresponding levels of pain intensity were scored on a visual analog scale (VAS) slide ruler. Results: Study data was obtained and analysed in all participants. Significantly higher EPT levels were determined by the female investigator compared with the male investigator (median 22 (IQR 12-31) vs. 8 (6-10) pain magnitude scores; p<0.0001), despite similar levels of reported pain intensity (1.9 (1.2-3.0) vs. 2.0 (1.1-3.4) VAS units; p>0.300). There were no differences in EPT levels between female and male subjects evaluated by female (p>0.300) and male (p=0.125) investigators, or between the first and second series of stimulation (p>0.300). Conclusions: Our finding of significantly higher EPT levels when study participants of both genders - despite no difference in reported pain intensity - were evaluated by a female than by a male investigator, indicates a potential impact of investigator gender on the individual perception of pain. Implications: By contributing to a better understanding of how individual pain threshold levels are potentially influenced by investigator gender, this study might facilitate future evaluation of pain conditions in both preclinical and clinical settings.

Are all pain tolerance tasks the same? Convergent validity of four behavioral pain tolerance tasks, self-reported capability for suicide, and lifetime self-injurious behaviors

OBJECTIVES

Discrepancies persist regarding the extent to which different pain measures provide similar information and relate to capability for suicide and self-injurious behaviors. This study examined pain threshold, tolerance, and persistence across four modalities (cold, heat, pressure, shock) and assessed associations with self-reported capability for suicide, non-suicidal self-injury (NSSI), and suicide attempts.

METHODS

A sample of 211 students who reported lifetime suicidal ideation completed four behavioral pain tasks and self-reported on capability for suicide, NSSI, and self-injurious behaviors.

RESULTS

All pain thresholds, tolerances, and persistences were positively correlated across the four tasks. Pain facets were related to self-reported capability for suicide with small effect sizes but generally did not differ across suicide attempt or NSSI histories.

CONCLUSIONS

Pain thresholds, tolerances, and persistences demonstrated convergent validity across the four modalities, suggesting that these tasks provide similar information. Although the relation between pain and self-injurious behaviors remains unclear, these tasks can generally be used interchangeably.

The Effect of Sleep Quality on Pain in Chilean Individuals with Musculoskeletal Disorders

Poor sleep quality (SQ) negatively affects pain associated with musculoskeletal disorders (MSD). As the level of economic development of a country determines its sanitary conditions, these can influence the sleep–pain relationship; therefore, it is relevant to generate evidence in the population with MSD in developing countries. This cross-sectional study sought to determine the effect of poor SQ on pain in Chilean individuals with MSD, controlling for sex and duration of pain (in months). Method: A total of 228 individuals were included. SQ was measured with the Pittsburg Sleep Quality Index (PSQI), pain (intensity, interference and distress relative to pain) was measured with visual analog scales. Structural equation modeling (SEM) was performed to analyze the effect of SQ on pain. Results: A high frequency of poor SQ was present in the studied group, and was more prevalent in women. The SEM model evidenced that poor SQ predicts greater pain. Sex influences sleep quality and pain, but not pain duration. Conclusions: These findings indicate that poor SQ predicts higher pain in MSD and that women exhibit worse SQ and more significant pain than men. Our findings support that SQ should be considered in the comprehensive approach to pain in individuals with MSD.

The influence of sex and level of physical activity on maximum tolerance to mechanical pain

Background

A difference in maximum tolerance to mechanical pain (MTMP) between the sexes is widely studied but there is still no consensus on whether the level of physical activity (PA) influences pain.

Objectives

To compare the MTMP between men and women with different levels of PA.

Methods

Sixty five individuals were divided in female (n = 35) and male group (n = 30). The main outcome measures were PA level and MTMP by pressure algometry. Pressure was applied three times on both sides at the following points: cervical (5^th and 7^th) and lumbar (3^th and 5^th) vertebrae; trapezius, rhomboid, gluteus, gastrocnemius, pectoralis major, tibialis anterior, and deltoid muscles, elbow, hand, knee, and ankle.

Results

It was observed that the PA level has little influence on the MTMP at all the assessed points and that men have greater MTMP than women.

Conclusion

Sex, not the PA level, influences the MTMP.

Masculinity's association with the interpersonal theory of suicide among military personnel

OBJECTIVE

Given that the majority of those who die by suicide are male, masculine traits have been examined as a potential link to the development of capability for suicide. However, research has not examined if such traits influence suicidal desire (i.e., thwarted belongingness, perceived burdensomeness). This study examined the influence of stereotypically masculine traits of stoicism, sensation seeking, physical aggression, verbal aggression, and self-reliance on all three components of the Interpersonal Theory of Suicide within a sample of male and female service members.

METHODS

A total of 953 service members were recruited as part of a larger study.

RESULTS

Sensation seeking and stoicism were positively associated with capability for suicide. With regard to suicidal desire, self-reliance and verbal aggression were positively associated with both perceived burdensomeness and thwarted belongingness. Stoicism was positively associated with thwarted belongingness.

CONCLUSIONS

Findings suggest that different masculine traits are associated with the three components of the Interpersonal Theory of Suicide in various ways. Stoicism may be an especially important masculine trait that influences a component of suicidal desire and capability for suicide.

The association of sex, age and FKBP5 genotype with common somatic symptoms: A replication study in the lifelines cohort study

OBJECTIVE

Our aim was to replicate a recent study that reported an association between the rs9470080 CC-genotype and common somatic symptoms in women, but not in men. Additionally, we quantified the genetic contribution to phenotypic variation in common somatic symptom levels.

METHODS

We used data from the Lifelines Cohort Study, including 28,299 participants (60.0% female; 44.2% CC-genotype; mean age 42.9 (14.2) years). Common somatic symptoms were measured with the SCL-90 SOM subscale. To assess the association between the rs9470080 genotype and SCL-90 SOM scores we applied similar analyses as the original study, including independent t-tests, two-way ANOVAs and a mixed ANOVA. To estimate the proportion of phenotypic variance in SCL-90 SOM scores explained by single nucleotide polymorphisms (SNPs), we used a genomic-relatedness-based restricted maximum-likelihood method.

RESULTS

We could not replicate the original study's findings. We found no association between the rs9470080 genotype and common somatic symptom levels in either female or male participants (F(1, 8775) = 1.07, p = 0.30 and F(1,13,903) = 0.01, p = 0.93, respectively). Genome-wide heritability analyses show that 12.1% (p = 2.1e-08) of the phenotypic variance in common somatic symptom levels in Lifelines can be explained by SNPs. The genetic contribution to common somatic symptom levels was higher in male participants (SNP-h² = 20.5%; p = 9.1e-08) than in female participants (SNP-h² = 12.0%, p = 2.8e-05).

CONCLUSION

Our findings of significant SNP-h² and the sex-specific differences herein, does warrant further sex-stratified research of individual genetic variants associated with common somatic symptoms. Preferably, further research should be performed within the analytic framework of a genome-wide association study.

"Big girls don't cry": the effect of the experimenter's sex and pain catastrophising on pain

OBJECTIVES

The expression of pain in males and females involves complex socio-psychological mechanisms. Males may report lower pain to a female experimenter to appear strong, whereas females may report higher pain to a male experimenter to appear weak and to seek protection. However, evidence to support these stereotypes is inconclusive. Individuals who catastrophise about pain rate higher pain than those who do not. How pain catastrophising interacts with the effect of the experimenter's sex on pain reports is yet to be explored. Thus, the aim of this study was to determine whether pain catastrophising moderated the effect of the experimenter's sex on pain reports in healthy males and females.

METHODS

Participants (n=60, 30 males) were assigned to one of four experimental conditions: males tested by male experimenters, males tested by female experimenters, females tested by male experimenters, and females tested by female experimenters. Participants completed the Pain Catastrophising Scale, and then sensitivity to heat and to blunt (pressure-pain threshold) and sharp stimuli was assessed on both forearms, and to high frequency electrical stimulation (HFS) administered to one forearm.

RESULTS

Females reported lower pressure-pain thresholds than males irrespective of the experimenters' sex. Females reported lower sharpness ratings to male than female experimenters only when the test stimuli were moderately or intensely sharp. Higher pain catastrophising scores were associated with higher sharpness ratings in females but not males. Additionally, higher pain catastrophising scores were associated with greater temporal summation of pain to HFS, and with lower pressure-pain thresholds in females who were tested by male experimenters.

CONCLUSIONS

These findings indicate that the experimenters' sex and the participant's pain catastrophising score influence pain reports, particularly in females. Awareness of these psychosocial factors is important in order to interpret pain responses in a meaningful way, especially when females are tested by male experimenters. A greater awareness of sex/gender role biases and their potential interaction with pain catastrophising may help researchers and clinicians to interpret pain reports in meaningful ways. In turn, this may help to improve delivery of treatments for patients with chronic pain.

Pressure pain thresholds in individuals with knee pain: a cross-sectional study

Background

Knee osteoarthritis (KOA), chronic widespread pain (CWP) and overweight/obesity are public health problems that often coincide, and there is a multifactorial and unclear relationship between them. The study aimed to (1) investigate pain sensitivity, assessed by pressure pain thresholds (PPTs), among women and men with knee pain and (2) associations with, respectively, radiographic KOA (rKOA), CWP, and overweight/obesity.

Methods

Baseline data from an ongoing longitudinal study involving 280 individuals with knee pain in the 30–60 age group. Pain sensitivity was assessed by PPTs on eight different tender points using a pressure algometer. The participants’ knees were x-rayed. Self-reported CWP and number of pain sites were assessed with a pain figure, and overweight/obesity was measured using body mass index (BMI), visceral fat area (VFA), and body fat percentage, assessed with a bioimpedance. Associations were analysed using regression analyses.

Results

Women reported lower PPTs than men (p < 0.001), but no PPTs differences were found between those with and without rKOA. Low PPTs was associated with female sex, more pain sites, CWP, and a higher VFA and body fat percentage. The tender points second rib and the knees were most affected. The prevalence of CWP was 38 %.

Conclusions

The modifiable factors, increased VFA, and body fat could be associated with increased pain sensitivity among individuals with knee pain. Longitudinal studies are needed to further investigate the associations.

Supplementary Information

The online version contains supplementary material available at 10.1186/s12891-021-04408-0.

An fNIRS Investigation of Masculinity, Femininity, and Sex on Nonparents' Empathic Response to Infant Cries

According to societal stereotypes, the female sex and people who are more feminine have been considered to be more empathic than males and people who are more masculine. Therefore, females and feminine individuals are expected to respond more empathically to an infant's cries. While this hypothesis was tested using self-report scales, it has not been explored thoroughly in terms of prefrontal cortex (PFC) activity, which may be a more objective means of measuring empathy. Specifically, the medial PFC (mPFC) is involved in social cognitive processing and thus a good proxy to measure the level of empathy. This study aims to (1) assess if the empathic response, in terms of medial PFC (mPFC) activity, to infant cries differ between sexes; (2) investigate if the empathic response is moderated by levels of masculinity and femininity. Functional near-infrared spectroscopy (fNIRS) was used to measure nonparent participants' (18 males, 20 females) mPFC response to infant cries of different pitches (high and low). The Toronto Empathy Questionnaire was used to measure trait empathy and Bem's Sex Role Inventory was used to measure the level of masculinity and femininity. Results revealed that biological sex had no significant effect on the empathic response towards infant cries of varying pitch. Furthermore, masculinity, not femininity, was correlated with an increase in empathic response in the mPFC to high but not low-pitch infant cries. We reason that this is because of the higher aversiveness and inflicted pain associated with higher-pitched cries, which induces more emotional and physical pain that masculine individuals seek to avoid. Overall, the results suggest that greater masculinity would imply greater mentalizing and processing of empathy-related information.

COPAHS Study: protocol of a randomised experimental study comparing the effects of hypnosis, mindfulness meditation, and spiritual practices on experimental pain in healthy adults

BACKGROUND

There has been an increasing interest in studying the potential benefits of so-called complementary and alternative approaches for pain management, such as hypnosis and mindfulness-based interventions. More recently, researchers have been interested in studying the effects of spiritual practices on pain experience as well. These practices may increase pain tolerance, result in a positive re-appraisal of pain and influence other psychological variables that are known to be associated with pain experience. The purpose of this study is to evaluate and compare the immediate effects of self-hypnosis, mindfulness meditation, and a spiritual intervention relative to a control condition for increasing pain tolerance and reducing pain intensity and pain-related stress, in response to experimental painful stimulation.

METHODS AND ANALYSIS

Recruitment is anticipated to start in November 2020. This is a randomised quantitative experimental mixed-design repeated-measures study with three assessment points: baseline (T0), pre-test (T1) and post-test (T2). Eligible healthy adults will be randomised to one of the four study conditions. Interventions will be a 20-minute audio-guided practice of either self-hypnosis, mindfulness meditation, or Christian prayer. Participants in the control group will not be instructed to use any specific strategy during the painful stimulation. Participants will be submitted to a first cycle of Cold Pressor Arm Wrap. They will then listen to a 20-minute audio recording inducing one of the three interventions, or, in the case of the control group, to a 20-minute audio recording of text from a natural history textbook. Primary outcomes are pain intensity and pain tolerance. Pain-related stress as measured by salivary cortisol level and heart rate variability are secondary outcomes.

ETHICS AND DISSEMINATION

This study was approved by ISPA-University Institute's internal Ethics Committee for Research on 3rd December 2018 (reference I/010/12/2018). Findings will be published in peer-reviewed indexed journals and presented at conferences.

TRIAL REGISTRATION NUMBER

ClinicalTrials.gov registry (NCT04491630). Stage: pre-results.

Men, Chronic Pain, and Prescription Pain Medication Use: The Role of Gender Role Beliefs in a Longitudinal Moderated Mediation Model

OBJECTIVE

Although past research has established that men with chronic pain are more likely to misuse prescription pain medications in a myriad of ways compared with women, little is known about men's medication use in the context of their gender role beliefs. The aim of the present study was to examine the role of men's domestic gender role beliefs on their use of prescription pain medication for chronic pain.

METHODS

Using a nationally representative data set with 304 men with chronic pain, this study examined a longitudinal moderated mediation model in which pain interference mediates the longitudinal relationship between somatic amplification and prescription pain medication use, with domestic gender role beliefs as a moderator of the aforementioned mediated relationship.

RESULTS

Results indicated a significant moderated mediation model in which pain interference fully mediated the relationship between somatic amplification and prescription pain medication use, with men's domestic gender role beliefs moderating this mediated relationship. Specifically, domestic gender role beliefs moderated the relationship between pain interference and prescription pain medication use. Men with higher levels of traditional domestic gender role beliefs strengthened the mediated relationship, contributing to increased prescription pain medication use.

CONCLUSIONS

These findings suggest that although men's perceptions of somatic stimuli through its perceived interference contribute to their medication use, the extent to which they consume prescription pain medication depends on their beliefs in domestic gender roles during chronic pain.

Gender Medicine and Physiotherapy: A Need for Education. Findings from an Italian National Survey

BACKGROUND

Gender medicine permeates all sectors of medicine, from prevention to treatment and rehabilitation; it aims to customize the care path, ensuring equity in the access to health care system services. It is unclear to what extent physiotherapists' treatment choices align with gender medicine principles. The aim of this survey is to detect the need of Italian physiotherapists to deepen knowledge in gender medicine.

MATERIALS AND METHODS

An 18-item survey assessed the characteristics of responders about knowledge of gender medicine. An online survey was performed in 2020 using SurveyMonkey Software. Data were analyzed by statistical regression.

RESULTS

A total of 617 physiotherapists voluntarily participated in the study (53.84% of the target population). The majority of responders (68.4%) declared having general information about gender medicine, but 55.43% of them claimed to have heard of it but did not know properly what gender medicine was about; 92.38% of the physiotherapists believed that they needed training to acquire knowledge in gender medicine.

CONCLUSIONS

Gender equity matters for health. Moderate knowledge of gender medicine' principles and modest application of these findings were used in clinical practice of physiotherapy. Physiotherapists declared that they need training in gender medicine.

The gender context of pain

Pain is a major source of global suffering, with women bearing the greatest burden. Alongside biology, psychological and social factors, including gender, help explain these differences. However, there has been no direct attempt to develop a unified social psychological model of men and women's pain. By drawing on approaches to both gender and pain, a gender context model of pain is presented. It proposes that pain is partly influenced by the gender context in which it occurs, which operates at both individual and interpersonal levels. The model is used to structure an appraisal of the existing evidence around gender and pain, and explore whether the model helps explain why such variation occurs. It is argued that despite evidence for an association between gender and pain, there are empirical gaps that need to be addressed. Implications and directions for future investigations into sex, gender and pain are considered.

Is There a Gender Self-Advocacy Gap? An Empiric Investigation Into the Gender Pain Gap

There are documented differences in the efficacy of medical treatment for pain for men and women. Women are less likely to have their pain controlled and receive less treatment than men. We are investigating one possible explanation for this gender pain gap: that there is a difference in how women and men report their pain to physicians, and so there is a difference in how physicians understand their pain. This paper describes an exploratory study into gendered attitudes towards reporting uncontrolled pain to a physician. This exploratory study provided subjects with a vignette describing a situation in which their pain is not being treated adequately and asked them questions about their attitudes towards self-advocacy and the strategies they would likely use to express themselves. We found that women scored higher than men on measures of patient likelihood to self-advocate. Women also reported intending to use more varied self-advocacy strategies than men. This suggests it is unlikely that patient's communication styles are to blame for the gender pain gap.

No Pain, No Gain? The Influence of Gender and Athletic Status on Reporting Pain in Sports

Collegiate athletes are frequently exposed to pain/injury, which has the potential to negatively impact their physical and psychological health. This quasi-experimental study investigated the influence of gender and athletic status on deciding whether pain should be reported to the head coach in a vignette. Participants included 236 undergraduates who read four vignettes describing athletes (two men, two women) who were experiencing pain while playing a sport and made recommendations about whether the athlete should report the pain. Regardless of the gender of the athlete in the vignette, women and non-Division I athletes were more confident that the pain should be reported to the coach than men and athletes. Division I athletes’ recommendations for others to report pain did not align with what they reported practicing themselves. These results suggest that athletes and coaches should receive education about the factors that may lead an athlete to choose not to report pain.

An Emerging Role for Prolactin in Female-Selective Pain

Women experience many pain conditions more frequently when compared with men, but the biological mechanisms underlying sex differences in pain remain poorly understood. In particular, little is known about possible sex differences in peripheral nociceptors, the fundamental building blocks of pain transmission. Emerging evidence reveals that prolactin (PRL) signaling at its cognate prolactin receptor (PRLR) in primary afferents promotes nociceptor sensitization and pain in a female-selective fashion. In this review, we summarize recent progress in understanding the female-selective role of PRL/PRLR in nociceptor sensitization and in pathological pain conditions, including postoperative, inflammatory, neuropathic, and migraine pain, as well as opioid-induced hyperalgesia. The clinical implications of the peripheral PRL/PRLR system for the discovery of new therapies for pain control in women are also discussed.

Gender and sex independently associate with common somatic symptoms and lifetime prevalence of chronic disease

Sex and gender influence health differently. Associations between sex and health have been extensively studied, but gender (i.e. psychosocial sex) has been largely neglected, partly due to the absence of gender measures in cohort studies. Therefore, our objective was to test the unique associations of gender and sex with common somatic symptoms and chronic diseases, using a gender index created from existing cohort data. We applied LASSO logistic regression to identify, out of 153 unique variables, psychosocial variables that were predictive of sex (i.e. gender-related) in the Dutch LifeLines Cohort Study. These psychosocial variables covered gender roles and institutionalized gender. Using the estimated coefficients, gender indexes were calculated for each adult participant in the study (n = 152,728; 58.5% female; mean age 44.6 (13.1) years). We applied multiple ordinal and logistic regression to test the unique associations of the gender index and sex, and their interactions, with common somatic symptoms assessed by the SCL-90 SOM and self-reported lifetime prevalence of chronic diseases, respectively. We found that in 10.1% of the participants the gender index was not in line with participants' sex: 12.5% of men and 8.4% of women showed a discrepancy between gender index and sex. Feminine gender characteristics are associated with increased common somatic symptoms and chronic diseases, especially in men. Female sex is associated with a higher common somatic symptom burden, but not with a higher prevalence of chronic diseases. The study shows that gender and sex uniquely impact health, and should be considered in epidemiological studies. Our methodology shows that consideration of gender measures in studies is necessary and feasible, based on data generally present in cohort studies.

Psychological Characteristics in Patients with Chronic Complex Regional Pain Syndrome: Comparisons with Patients with Major Depressive Disorder and Other Types of Chronic Pain

Objective

This study investigated psychological characteristics of patients with chronic complex regional pain syndrome (CRPS) and examined relationships between psychosocial factors and pain severity.

Methods

In total, 76 patients with CRPS, 95 patients with other types of chronic pain, 171 healthy controls, and 66 patients with major depressive disorder (MDD) were included. Minnesota Multiphasic Personality Inventory (MMPI-2) profiles and scores on the Beck Depression Inventory and State-Trait Anxiety Inventory were calculated. Pain intensity was measured using a visual analog scale (VAS).

Results

Patients with CRPS scored higher on the Hypochondriasis (Hs), Depression (D), Hysteria (Hy), Paranoia (Pa), and Psychasthenia (Pt) scales of the MMPI-2 compared to healthy controls. The CRPS group scored lower on the D, Psychopathic deviate (Pd), Pa, Pt, Schizophrenia (Sc), and Social introversion (Si) scales compared to the MDD group. Although CRPS patients reported higher levels of pain than patients with other types of pain, the MMPI profiles of the two pain groups did not differ significantly. Linear regression analyses revealed that pain severity was significantly associated with depression and scores on the Masculinity-Femininity (Mf) scale.

Conclusion

This is the first comparative study of the psychological characteristics of chronic CRPS patients, healthy controls, and patients with MDD. The neurotic profiles of CRPS patients were more psychologically adaptable than were those of patients with MDD; however, this profile was shared by both pain groups. The present findings further showed that, although pain severity was not a major contributor to depression, patients with CRPS should be evaluated for depressive symptoms.

Suicide Risk and Restricted Emotions in Women: The Diverging Effects of Masculine Gender Norms and Suicide Capability

This study investigated whether gender moderated the association between masculine socialization pressures of restrictive emotionality and suicide risk through suicide capability (i.e., fearlessness about death). A sample of inpatients admitted for recent suicidality (n = 194) completed validated measures of restrictive emotionality, fearlessness about death, and current suicide risk. A moderated mediation effect was found opposite the hypothesized direction: fearlessness about death mediated the relationship between endorsement of the masculine gender norm of restrictive emotionality and suicide risk in women, but not men. Gender did not moderate the association between restrictive emotionality and fearlessness about death. The diverging gender effects suggest that the masculine gender norm of restrictive emotionality is associated with suicide capability in men and women, while acquired fearlessness about death is more informative of risk for suicide in women than men.