Beta-endorphin response to exercise. An update

Peripheral to brain and hippocampus crosstalk induced by exercise mediates cognitive and structural hippocampal adaptations

Endurance exercise leads to robust increases in memory and learning. Several exercise adaptations occur to mediate these improvements, including in both the hippocampus and in peripheral organs. Organ crosstalk has been becoming increasingly more present in exercise biology, and studies have shown that peripheral organs can communicate to the hippocampus and mediate hippocampal changes. Both learning and memory as well as other hippocampal functional-related changes such as neurogenesis, cell proliferation, dendrite morphology and synaptic plasticity are controlled by these exercise responsive peripheral proteins. These peripheral factors, also called exerkines, are produced by several organs including skeletal muscle, liver, adipose tissue, kidneys, adrenal glands and circulatory cells. Previous reviews have explored some of these exerkines including muscle-derived irisin and cathepsin B (CTSB), but a full picture of peripheral to hippocampus crosstalk with novel exerkines such as selenoprotein 1 (SEPP1) and platelet factor 4 (PF4), or old overlooked ones such as lactate and insulin-like growth factor 1 (IGF-1) is still missing. We provide 29 different studies of 14 different exerkines that crosstalk with the hippocampus. Thus, the purpose of this review is to explore peripheral exerkines that have shown to exert hippocampal function following exercise, demonstrating their particular effects and molecular mechanisms in which they could be inducing adaptations.

Combined Exercise and Diet Induce Airway Hyperreactivity While Reducing Liver Steatosis in Mice with Diet-Induced Obesity

BACKGROUND

Obesity is a multi-organ system disease, which is associated with, e.g., a higher prevalence of non-alcoholic fatty liver disease (NAFLD) and asthma. Little is known regarding the effect of obesity-related parameters (including liver integrity) and the respiratory phenotype after a combination of physical activity and diet.

METHODS

Thirty-two C57BL/6 mice were, after 27 weeks of a high fat diet (HFD), randomly assigned to two dietary interventions for three weeks: a HFD or a normal chow diet (NCD). In both dietary groups, half of the animals were subjected to a sub-maximal exercise protocol. Lung function, lung inflammation, liver histology, and metabolic profile were determined.

RESULTS

Mice with obesity did not show airway hyperreactivity after methacholine provocation. Sub-maximal exercise with diet (NCD/E) induced a significant reduction in forced expiratory volume in 0.1 s after methacholine provocation. NCD/E had significantly more neutrophils and inflammation (IFN-γ, TNF-α, IL-4, and IL-17F) in bronchoalveolar lavage compared to non-exercising mice on a HFD (HFD/NE). However, more epithelial injury (serum surfactant protein D and IL-33) was seen in HFD/NE. Additionally, hepatic steatosis and fibrosis were reduced by combined diet and sub-maximal exercise.

CONCLUSIONS

Combining sub-maximal exercise with diet induced airway hyperreactivity and pulmonary inflammation, while body weight, hepatic steatosis, and fibrosis improved.

The Perceived Benefits and Self-Efficacy of an Exercise Intervention on Tobacco Withdrawal Symptoms: A Qualitative Study Based on the Health Belief Model

Background

This study examined the effectiveness of an exercise programme as an adjunct to smoking cessation treatments. The effects of exercise on smoking habits and tobacco withdrawal symptoms (TWS) were evaluated among smokers who were in the pre-contemplation and contemplation stages.

Methods

This was a case study with convenience sampling techniques. This study lasted approximately 2 years, beginning in February 2016. This study was divided into two phases: an intervention phase followed by an interview. The participants were invited to undergo the 8-week supervised moderate aerobic exercise programme. This qualitative study involved 14 participants selected from the intervention phase. They were interviewed about their experiences using a semi-structured questionnaire guided by the health belief model.

Results

This study involved 14 participants who were aged between 26 years old and 40 years old and smoked from 11 to 20 cigarettes per day. Most participants perceived benefits and self-efficacy regarding smoking habits and tobacco withdrawal symptoms (TWS) following the exercise intervention.

Conclusion

This study demonstrated that moderate exercise might be helpful in increasing self-efficacy in smoking cessation and the findings encourage further research on exercise programmes as an adjunct to smoking cessation treatments in Malaysia.

The Nexus of Training Duration, Body Image, Nutritional Practices, and Mental Health: Insights from a Strength Training Cohort

This study investigated the intricate relationship between strength training and its effects on body image, psychological health, and nutritional habits. By examining 605 participants, divided into two groups based on training frequency, the research aimed to discern how varying intensities of training influenced different wellness facets. The investigation employed a comprehensive survey, gathering demographic data, training specifics, dietary patterns, and psychological characteristics, utilizing statistical tools for analysis. Results unveiled significant differences in dietary habits and psychological profiles between groups with higher and lower training frequencies. The group with more frequent training displayed less favourable health outcomes and suboptimal dietary habits, challenging the prevailing notion that increased training frequency leads to better health. The study emphasized the necessity of a balanced approach to physical training, highlighting the need for personalized strategies that encompass both physical and mental health considerations. The findings exposed the complexities of training regimens and their broader implications on individual health, suggesting that enhanced training frequency alone does not assure improved health outcomes. This research significantly contributed to the domain by providing insights into how the frequency of strength training could differentially affect health and well-being, offering valuable guidelines for fitness professionals and healthcare providers.

Fractional amplitude of low-frequency fluctuations associated with μ-opioid and dopamine receptor distributions in the central nervous system after high-intensity exercise bouts

Introduction

Dopaminergic, opiod and endocannabinoid neurotransmission are thought to play an important role in the neurobiology of acute exercise and, in particular, in mediating positive affective responses and reward processes. Recent evidence indicates that changes in fractional amplitude of low-frequency fluctuations (zfALFF) in resting-state functional MRI (rs-fMRI) may reflect changes in specific neurotransmitter systems as tested by means of spatial correlation analyses.

Methods

Here, we investigated this relationship at different exercise intensities in twenty young healthy trained athletes performing low-intensity (LIIE), high-intensity (HIIE) interval exercises, and a control condition on three separate days. Positive And Negative Affect Schedule (PANAS) scores and rs-fMRI were acquired before and after each of the three experimental conditions. Respective zfALFF changes were analyzed using repeated measures ANOVAs. We examined the spatial correspondence of changes in zfALFF before and after training with the available neurotransmitter maps across all voxels and additionally, hypothesis-driven, for neurotransmitter maps implicated in the neurobiology of exercise (dopaminergic, opiodic and endocannabinoid) in specific brain networks associated with "reward" and "emotion."

Results

Elevated PANAS Positive Affect was observed after LIIE and HIIE but not after the control condition. HIIE compared to the control condition resulted in differential zfALFF decreases in precuneus, temporo-occipital, midcingulate and frontal regions, thalamus, and cerebellum, whereas differential zfALFF increases were identified in hypothalamus, pituitary, and periaqueductal gray. The spatial alteration patterns in zfALFF during HIIE were positively associated with dopaminergic and μ-opioidergic receptor distributions within the 'reward' network.

Discussion

These findings provide new insight into the neurobiology of exercise supporting the importance of reward-related neurotransmission at least during high-intensity physical activity.

Endogenous Opioids and Exercise-Related Hypoalgesia: Modern Models, Measurement, and Mechanisms of Action

This chapter will focus on the role exercise appears to have on activation and modulating factors within the central nervous system related to endogenous like opioids and its possible contribution to exercise-induced hypoalgesia. The implications for the exercise-mediated alterations of CNS activation factors related to opioids, specifically endorphins and enkephalins, will be presented. In this update, we discuss utilization of new technology and methods to monitor mechanisms of opioid involvement to suggest their contribution with exercise mediated hypoalgesia as well as their relationships to alterations of perceptions of pain and mood. Several special populations were included to suggest that not all individuals will respond to the exercise by mediating hypoalgesia. Factors that may confound the current understanding and suggestions from the recent literature will be presented as well as suggestions for future investigations.

Can we improve exercise-induced hypoalgesia with exercise training? An overview and suggestions for future studies

Exercise-induced hypoalgesia refers to a reduction in pain sensitivity following a single bout of exercise, which has been shown to be diminished or impaired with aging and chronic pain. Exercise training (repeated bouts of exercise over time) is often recommended as a non-pharmacological treatment for chronic pain and age-related functional declines. However, whether exercise training can augment the exercise-induced hypoalgesia has not been well studied. The purpose of this paper is to 1) provide an overview of the existing literature investigating the effect of exercise training on the magnitude of exercise-induced hypoalgesia, and 2) discuss potential underlying mechanisms as well as considerations for future research. Given the paucity of randomized controlled trials in this area, the effects of exercise training on exercise-induced hypoalgesia are still unclear. Several potential mechanisms have been proposed to explain the impaired exercise-induced hypoalgesia in chronic pain and older individuals (e.g., endogenous opioid, cardiovascular, and immune system). Exercise training appears to induce physiological changes in those systems, however, further investigations are necessary to test whether this will lead to improved exercise-induced hypoalgesia. Future research should consider including a time- and age-matched non-training group and utilizing the same exercise protocol for testing exercise-induced hypoalgesia across intervention groups.

Exercise Is Medicine: How Do We Implement It?

Exercise is well known to have beneficial effects on various disease states. In this paper, we broadly describe the fundamental concepts that are shared among various disease states, including obesity, type 2 diabetes (T2D), cardiovascular disease (CVD), heart failure (HF), cancer, and psychological well-being, and the beneficial effects of exercise training within these concepts. We highlight issues involved in implementing exercise recommendations and describe the potential impacts and challenges to medical professionals and patients. Problems are identified and discussed with respect to the future roles of professionals in the current built environment with its limited infrastructure to support current physical activity recommendations.

β-Endorphins are not responsible for delayed gastric emptying of digestible solids after exercise in professional cyclists. A preliminary study

OBJECTIVE

It has been reported that professional cyclists had an accelerated solid gastric emptying which decreased by increasing the exercise intensity. That could be explained by a predominance of stress-dependent motility inhibitors such gastrointestinal hormones, neurotransmitters and or the predominance of the gastric inhibitory vagal motor circuit. The aim of this preliminary study was to evaluate the role of β-endorphins, inhibitors of gastric motility, in these findings.

METHODS

Gastric emptying of solids marked with Tc⁹⁹ while resting and plasmatic levels of β-endorphins were evaluated in 27 healthy controls and 19 professional cyclists (day 1). Besides, gastric emptying of solids was also assessed in cyclists when they reached 50% (day 1) and 75% (day 2) of the maximum oxygen consumption (low and high, respectively), during exercise on the cycle-ergometer. The third day, naloxone was administered in cyclists in order to block the β-endorphins receptors and gastric emptying was measured when they reached 75% of the maximum oxygen consumption.

RESULTS

Basal β-endorphin levels were lower in cyclists vs controls (p<0.05) and they increased with the exercise intensity (p<0.001). There were no significant differences in gastric emptying of solids with or without naloxone when 75% of the maximum oxygen consumption was reached.

CONCLUSIONS

The inhibitory effect of the exercise in the gastric emptying of solids does not seem to be secondary to the action of β-endorphins, that leaves the gastric inhibitory vagal motor circuit a more likely predominant role.

The Impacts of Supervised Exercise Intervention on Tobacco Withdrawal Symptoms

This study examined a supervised moderate-intensity aerobic exercise programme's effectiveness in regulating the Tobacco Withdrawal Symptoms (TWS) during temporary abstinence. This was a single group, pre and post-quasi intervention study. Thirty daily smokers participated in an 8-week supervised moderate-intensity aerobic exercise programme. We assessed the TWS, smoking urge, mood and stress-pleasure related hormonal variables after the aerobic exercise intervention. The measurements were conducted after overnight abstinence at baseline, post-intervention (at week-8) and post-detraining (at week-10). TWS components, smoking urge and mood were found to improve. For hormonal variables, cortisol and beta-endorphin except adrenaline showed insignificant changes at post-intervention and de-training. The findings suggest moderate-intensity exercise might help in reducing withdrawal symptoms and its adverse effects. Thus, exercise is an effective adjunct treatment in a smoking cessation programme.

Effect of Exercise on β-Endorphin and Its Receptors in Myasthenia Gravis Patients

This is a prospective observational study evaluating the change in β-endorphin (BE) and its receptors following exercise in patients with myasthenia gravis (MG) and their association with clinical improvement. Fifteen patients with mild to moderate MG, aged 16-70 years, who were able to do 6-Minute Walk Test (6-MWT) and had MG Quality of Life-15 (MGQoL-15) ≤ 45 without any contraindication for exercise were included. The patients walked 30 min daily for 3 months. The primary outcome at 3 months was > 50% improvement in MGQoL-15 from the baseline, and the secondary outcomes were MG Activities of Daily Living (MGADL), Hospital Anxiety and Depression Scale (HADS), number of steps, and distance covered on 6-MWT and adverse events. Plasma BE level, μ-opioid receptor (MOR), and δ-opioid receptor (DOR) were measured on admission and at 1 and 3 months. Twelve age- and gender-matched healthy controls who were not on regular exercise were included for comparison of BE, MOR, and DOR levels. Plasma BE level (P = 0.007) and DOR expression (P = 0.001) were lower in MG patients compared to the healthy controls. After 3 months of exercise, 6 patients improved. Plasma BE, MOR, and DOR levels increased in the first and decreased in the third month. MGQoL-15 (P < 0.001), HADS (P < 0.0001), number of steps (P < 0.007), distance (P = 0.030), and MGADL (P < 0.001) significantly improved compared to baseline. At 3 months, MGQoL-15 was associated with HADS score (P = 0.001), reduced depression (P = 0.013), MGADL (P = 0.035), and distance travelled on the 6-WMW test (P = 0.050). The improvement in depression was associated with higher BE level.

Effects of High-Intensity Interval Training (HIIT) on Patients with Musculoskeletal Disorders: A Systematic Review and Meta-Analysis with a Meta-Regression and Mapping Report

The aim was to assess the impact of high-intensity interval training (HIIT) on patients with musculoskeletal disorders. We conducted a search of Medline, Embase, PEDro, and Google Scholar. We conducted a meta-analysis to determine the effectiveness of HIIT on pain intensity, maximal oxygen consumption (VO₂ max), disability, and quality of life (QoL). We employed the GRADE and PEDro scales to rate the quality, certainty, and applicability of the evidence. Results showed significant differences in pain intensity, with a moderate clinical-effect (SMD = −0.73; 95% CI: −1.40–−0.06), and in VO₂ max, with a moderate clinical-effect (SMD = 0.69; 95% CI: 0.42–0.97). However, the meta-analysis showed no statistically significant results for disability (SMD = −0.34; 95% CI: −0.92–0.24) and QoL (SMD = 0.40; 95% CI: −0.80–1.60). We compared HIIT against other exercise models for reducing pain intensity and increasing VO₂ max. The meta-analysis showed no significant differences in favour of HIIT. Meta-regression analysis revealed that pain intensity scores were negatively associated with VO₂ max (R² = 82.99%, p = 0.003). There is low-moderate evidence that the HIIT intervention for patients with musculoskeletal disorders can reduce pain intensity and increase VO₂ max but has no effect on disability and QoL. Results also showed that HIIT was not superior to other exercise models in reducing pain intensity and increasing VO₂ max.

Results from the Thailand 2022 report card on physical activity for children and youth

Background/objective

The effort to create physical activity (PA) opportunities for Thai youth, prior to 2020, was making good progress. However, the unexpected advent of the Covid-19 epidemic has posed significant challenges to maintain PA level of youth. The Thailand 2022 Report Card on Physical Activity for Children and Youth presents measurements of PA-related indicators based on the Global Matrix, with additional indicators that are relevant for childhood development.

Methods

Several data sources were employed to develop the indicators, namely: 1) The Thailand Report Card Survey 2021; 2) School health and facility data; 3) Student health indicators from the Ministry of Public Health; and 4) Relevant resources to support the development of the policy indicator.

Results

Overall, only 27% of Thai children and youth met the 60-min PA daily threshold (grade D). While behavioral indicators were mostly graded ‘poor’ (between C and F), the source of influence (i.e., family) indicators showed better grades (between A and C). One-third (33%) of the youngsters suffered from moderate-to-severe level of stress/anxiety (grade B). Overweight and sleep indicators received grades of A or A-, whereas bullying and student engagement received a grade of B. The performance on the physical literacy indicator was graded C+.

Conclusion

With the main message “Let's Move - Boost Happiness,” the results from Thailand 2022 Report Card call for a collaborative effort involving multiple sectors to improve PA and happiness of children and youth. A more comprehensive PA promotion strategy is required to provide clear direction and guidance for schools, families, and communities in order to maintain gains and raise the overall level of youth PA in Thailand.

The Architecture of Happiness

Happiness is an increasingly prominent topic of interest across academia. However, relatively little attention has been paid to how it is created, especially not in a multidimensional sense. By ‘created’ we do not mean its influencing factors, for which there is extensive research, but how it actually forms in the person. The work that has been done in this arena tends to focus on physiological dynamics, which are certainly part of the puzzle. But they are not the whole picture, with psychological, phenomenological, and socio cultural processes also playing their part. As a result, this paper offers a multidimensional overview of scholarship on the ‘architecture’ of happiness, providing a stimulus for further work into this important topic.

Restless Leg Syndrome in Hemodialysis Patients: A Narrative Review

BACKGROUND

Restless legs syndrome (RLS) is a clinical entity characterized by sensory-motor manifestations commonly observed in end-stage renal illness. Evidence suggests that RLS is a multifactorial phenomenon that can be influenced by many critical factors, including genetic predisposition, dietary patterns, and deficiency in some vitamins. Iron metabolism disorders and metabolic derangements have been generally accepted as predisposing elements in RLS. Furthermore, both pharmacological and neuroimaging studies demonstrated dopamine deficiency and dopamine receptors decrease in basal ganglia during RLS.

REVIEW SUMMARY

A literature search was done in three databases (PubMed, Google Scholar, and Cochrane) to identify the pertinent articles discussing the epidemiology, pathogenesis, and management of RLS in hemodialysis patients. RLS can affect the morbidity and mortality of patients treated with dialysis. It also has significant impacts on the quality of life since it can lead to insomnia, increased fatigue, mental health troubles, and other movement problems. Appropriate measures should be considered in this particular population so to prevent and treat RLS. Many drugs and other nonpharmacological methods have been investigated to attenuate the disease's severity. No treatment, however, could offer long-term effects.

CONCLUSION

Further efforts are still required to improve the understanding of RLS pathogenic trends to find more specific and efficient therapies. A wide range of treatment options is available. However, it can be individualized according to the patients' several factors.

The Clash of Two Epidemics: the Relationship Between Opioids and Glucose Metabolism

PURPOSE OF REVIEW

We are currently in the midst of a global opioid epidemic. Opioids affect many physiological processes, but one side effect that is not often taken into consideration is the opioid-induced alteration in blood glucose levels.

RECENT FINDINGS

This review shows that the vast majority of studies report that opioid stimulation increases blood glucose levels. In addition, plasma levels of the endogenous opioid β-endorphin rise in response to low blood glucose. In contrast, in hyperglycaemic baseline conditions such as in patients with type 2 diabetes mellitus (T2DM), opioid stimulation lowers blood glucose levels. Furthermore, obesity itself alters sensitivity to opioids, changes opioid receptor expression and increases plasma β-endorphin levels. Thus, opioid stimulation can have various side effects on glycaemia that should be taken into consideration upon prescribing opioid-based medication, and more research is needed to unravel the interaction between obesity, glycaemia and opioid use.

Components of Active Music Interventions in Therapeutic Settings—Present and Future Applications

Musical interventions in therapy have become increasingly relevant for rehabilitation in many clinics. What was long known for physiotherapy training—that the agency of the participant is crucial and moving is much more efficient for rehabilitation success than being moved—has over recent years also been shown to be true for music therapy. Accumulating evidence suggests that active musical interventions are especially efficient at helping rehabilitation success. Here, we review various approaches to active music therapy. Furthermore, we present several components that allow for manipulating musical expressiveness and physical engagement during active musical interventions, applying a technology-based music feedback paradigm. This paper will allow for a transfer of insights to other domains of music-based therapeutic interventions.

Exercise and Manual Therapy for the Treatment of Primary Headache: An Umbrella and Mapping Review

OBJECTIVE

The main aim of this study was to assess through systematic review the efficacy of exercise and manual therapy (MT) interventions in individuals with primary headache.

METHODS

In this umbrella review, 2 authors reviewed systematic reviews by searching the Cochrane Database of Systematic Reviews, MEDLINE, PEDro, Web of Science, and Google Scholar. Systematic reviews that evaluated the effectiveness of MT. Exercise-based interventions, or both in patients with primary headaches were included. Methodological quality was analyzed using the ROBIS scale, and the strength of evidence was established according to the Grading Criteria of the Physical Activity Guidelines Advisory Committee.

RESULTS

Thirty-one systematic reviews containing 79 trials and involving 9103 patients were included. The 7 exercise-related systematic reviews reported beneficial effects on primary headache based on unclear to moderate evidence. Of the 23 MT-related systematic reviews, 11 reported enhanced effectiveness compared with usual care; however, overall heterogeneity and risk of bias were high. Systematic reviews that evaluated the effectiveness of MT, exercise-based interventions, or both in patients with primary headaches were included.

CONCLUSION

Results show that exercise could be an effective therapy for the treatment of primary headache, with moderate to limited quality of evidence regarding the positive effects in terms of pain intensity and frequency and duration of headache. Moderate quality of evidence was found regarding the ability of MT to reduce pain intensity in patients with tension-type headaches, but quality of evidence was limited in terms of frequency of headache and disability and pain reduction in patients with migraine.

IMPACT

Exercise could be an effective treatment in patients with primary headache. Manual therapy showed limited evidence to reduce pain intensity in patients with tension-type headache. It is not possible to establish a preferential exercise protocol or MT program, so psychosocial and behavioral variables need to be considered in future studies.

Tobacco smoking among physicians and medical students

Tobacco smoking is a mental and behavioral disease. It causes significant pathology and premature death in more than seven million individuals a year around the globe. Because smoking is such important public health issue, the general public will benefit from targeted preventive strategies. Medical doctors have a vital role in smoking cessation of their patients. Non-smokers are more successful in this role than chronic smokers. Governmental regulation on smoking, as well as strict no-smoke policy in hospitals and university campuses will help not only medical students, other health workers and the general public to quit smoking and contribute to the general good health of this population. The aim of this comment is to analyse the current smoking habits of physicians and medical students and presents policies and other help to the medical students to stop tobacco smoking.

Effects of mento-physical exercises on mental fatigue of shift work

Objectives. This study aims to investigate whether mento-physical exercises can decrease mental fatigue during shift work. Methods. Research subjects including the control room staff of an urban train system were chosen randomly, for whom mental fatigue was assessed before and after rest breaks for control and experimental groups. A new protocol was applied in the experimental group, including breathing exercises, isometric and isotonic exercises, and progressive relaxation during the inter-shift break. A designed questionnaire and the Stroop test were used to evaluate fatigue and the reaction time, respectively. Results. Pre and post-test results showed that mental, visual and physical fatigue and reaction time decreased by 14.48, 49.22, 26.85 and 8.35% in the control group and 36.42, 48.48, 76.37 and 20.56% in the experimental group, respectively. Conclusions. At the 5% α level, Student's t test showed that mento-physical exercises effectively decreased mental and physical fatigue as well as reaction time in the experimental group compared to the control group.

Metabolic Syndrome and Psychological Effects of Exercise in Hemodialysis Patients

Metabolic syndrome (MS) and anxiety disorders are common problems among hemodialysis patients (HD). However, there have been no studies defining the role of physical activity in reducing anxiety in HD patients with MS. This study was aimed to determine the effects on the severity of anxiety of a four-week rehabilitation program for HD patients, with or without metabolic syndrome (MS), planned and adapted to their abilities. The study was single-center, interventional, non-randomized, and prospective. Fifty-eight individuals completed the project (28 HD patients and 30 controls (C) with normal kidney function). Each group was divided into two subgroups with respect to MS. The mean age of the subjects in the HD and C groups was 56.9 ± 13.3 years (x¯ ± SD) and 61.5 ± 8.3 years (x¯ ± SD), respectively. Planned and adapted to the patient's abilities, the rehabilitation program based on physiotherapy was provided to each subject for 4 weeks. Baseline and post-intervention determined anxiety levels using the State-Trait Anxiety Inventory (STAI). The X1 scale tests state anxiety, and the X2 scale tests trait anxiety. Post-intervention, there was no significant difference in the intensity of state anxiety observed in HD patients compared to C with normal renal function, as observed before the program. After four weeks of regular physical activity planned and adapted to the patient's abilities in an inpatient ward, the level of state anxiety (X1) and trait anxiety (X2) lowered considerably in all HD patients (respectively: 35.1 ± 8.0 vs. 29.2 ± 5.0, p = 0.001 for X1 and 41.8 ± 9.1 vs. 38.1 ± 5.9, p = 0.008 for X2). The rehabilitation program significantly reduced the intensity of state anxiety (X1) in HD patients with MS (35.8 ± 7.9 vs. 29.2 ± 5.1; p = 0.01). The rehabilitation program helped to significantly reduce the intensity of trait anxiety (X2) in HD patients without MS (41.9 ± 10.7 vs. 36.9 ± 5.9; p = 0.04). Four-week physical activity planned and adapted to the patient's abilities reduces the intensity of anxiety in HD patients and controls with normal renal function. HD patients with MS benefit more in terms of reducing perceived state anxiety, and HD patients without MS in terms of reducing trait anxiety.

Aerobic exercise with blood flow restriction causes local and systemic hypoalgesia and increases circulating opioid and endocannabinoid levels

This study examined the effect of aerobic exercise with and without blood flow restriction (BFR) on exercise-induced hypoalgesia and endogenous opioid and endocannabinoid systems. In a randomized crossover design, pain-free individuals performed 20 min of cycling in four experimental trials: 1) low-intensity aerobic exercise (LI-AE) at 40% V̇o_2max; 2) LI-AE with low-pressure BFR (BFR40); 3) LI-AE with high-pressure BFR (BFR80); and 4) high-intensity aerobic exercise (HI-AE) at 70% V̇o_2max. Pressure pain thresholds (PPTs) were assessed before and 5 min postexercise. Circulating concentrations of beta-endorphin and 2-arachidonoylglycerol were assessed before and 10 min postexercise. In the exercising legs, postexercise PPTs were increased following BFR40 and BFR80 compared with LI-AE (23-32% vs. 1-2% increase, respectively). The increase in PPTs was comparable to HI-AE (17-20% increase) with BFR40 and greater with BFR80 (30-32% increase). Both BFR80 and HI-AE increased PPTs in remote areas of the body (increase of 26-28% vs. 19-21%, respectively). Postexercise circulating beta-endorphin concentration was increased following BFR40 (11%) and HI-AE (14%), with the greatest change observed following BFR80 (29%). Postexercise circulating 2-arachidonoylglycerol concentration was increased following BFR40 (22%) and BFR80 (20%), with the greatest change observed following HI-AE (57%). Addition of BFR to LI-AE can trigger both local and systemic hypoalgesia that is not observed follow LI-AE alone and activate endogenous opioid and endocannabinoid systems of pain inhibition. Compared with HI-AE, local and systemic hypoalgesia following LI-AE with high-pressure BFR is greater and comparable, respectively. LI-AE with BFR may help pain management in load-compromised individuals.NEW & NOTEWORTHY We have shown that performing blood flow restriction (BFR) during low-intensity aerobic exercise can trigger local and systemic hypoalgesia, which is not typically observed with this intensity of exercise. High-pressure BFR triggers greater and comparable hypoalgesia than high-intensity aerobic exercise in the exercising limbs and remote areas of the body, respectively. Performing BFR during low-intensity aerobic exercise activates the opioid and endocannabinoid systems, providing novel insight into potential mechanisms of hypoalgesia with BFR exercise.

Effects of Physiotherapy vs. Acupuncture in Quality of Life, Pain, Stiffness, Difficulty to Work and Depression of Women with Fibromyalgia: A Randomized Controlled Trial

BACKGROUND

Fibromyalgia is a chronic clinical condition characterized by pain and other associated symptoms that have a negative impact on the quality of life of the affected person. The objective of this study was to assess the effectiveness of a core stability training physiotherapy program compared to an acupuncture treatment on quality of life, pain, joint stiffness, difficulty to work and depression of women with fibromyalgia.

METHODS

This was a single-blind, randomized clinical controlled trial. Women with fibromyalgia were randomized to a core stability physiotherapy program group (n = 45), an acupuncture treatment group (n = 45) and a control group (n = 45) for 13 weeks. Measurements were taken at baseline (week 0), post-intervention (week 6) and at follow-up (week 13). The primary outcome measure was quality of life (Spanish Fibromyalgia Impact Questionnaire). The secondary outcome measures were pain, joint stiffness, difficulty to work and depression (Visual Analogue Scale).

RESULTS

In total, 103 participants completed the study. The results, from a descriptive perspective, showed improvements in all the outcome measures in both intervention groups (physiotherapy and acupuncture) at weeks 6 and 13 in relation to week 0 and in comparison to the control group. Only the difficulty to work measure in the acupuncture group showed a slight decrease at week 13. In particular, mean (±SD) Spanish Fibromyalgia Impact Questionnaire score at 6 weeks was 62.89 ± 16.91 for the physiotherapy group, 62.5 ± 18.09 for the acupuncture group and 67.45 ± 17.07 for the control group. However, these improvements were not statistically significant.

CONCLUSION

Core stability-based physiotherapy and acupuncture showed non-significant improvements in quality of life, pain, joint stiffness, difficulty to work and depression in women with fibromyalgia.

Roles of β-Endorphin in Stress, Behavior, Neuroinflammation, and Brain Energy Metabolism

β-Endorphins are peptides that exert a wide variety of effects throughout the body. Produced through the cleavage pro-opiomelanocortin (POMC), β-endorphins are the primarily agonist of mu opioid receptors, which can be found throughout the body, brain, and cells of the immune system that regulate a diverse set of systems. As an agonist of the body's opioid receptors, β-endorphins are most noted for their potent analgesic effects, but they also have their involvement in reward-centric and homeostasis-restoring behaviors, among other effects. These effects have implicated the peptide in psychiatric and neurodegenerative disorders, making it a research target of interest. This review briefly summarizes the basics of endorphin function, goes over the behaviors and regulatory pathways it governs, and examines the variability of β-endorphin levels observed between normal and disease/disorder affected individuals.

Pelvic-floor relaxation techniques using biofeedback – more effective therapy for chronic prostatitis/chronic pelvic pain syndrome

Objective:

Chronic prostatitis/chronic pelvic pain syndrome (CP/CPPS) is characterized by pelvic pain and voiding symptoms, the management of which is challenging. The present study was designed to assess the efficacy of biofeedback and pelvic-floor relaxation treatment for CP/CPPS.

Methods:

A total of 84 patients diagnosed with CP/CPPS were randomly assigned to one of the two groups: conventional therapy (group A) and pelvic-floor muscle relaxation and biofeedback (group B). The Biofeedback and Electrical Stimulation apparatus was used for pelvic-floor muscle electrical stimulation and relaxation with biofeedback. National Institutes of Health Chronic Prostatitis Symptom Index (NIH-CPSI) scores were evaluated at the start of therapy, after 3 months of treatment and at 6 months (3 months after last treatment received).

Results:

At 3 months, patients in both groups had a significant decrease (improvement in symptoms) in NIH-CPSI scoring. However, at 6 months, only 19 (47.5%) patients in group A maintained a fall in NIH-CPSI score >6 compared with 37 (94.8%) patients in group B ( p<0.05). At 6 months, there was significant decrease in NIH-CPSI score in group B, whereas in group A, scores had increased (worsening of symptoms).

Conclusions:

Pelvic-floor muscle relaxation and biofeedback training is a safe and effective treatment for CP/CPPS with sustained efficacy.

Blunted endogenous opioid release following an oral dexamphetamine challenge in abstinent alcohol-dependent individuals

Addiction has been proposed as a 'reward deficient' state, which is compensated for with substance use. There is growing evidence of dysregulation in the opioid system, which plays a key role in reward, underpinning addiction. Low levels of endogenous opioids are implicated in vulnerability for developing alcohol dependence (AD) and high mu-opioid receptor (MOR) availability in early abstinence is associated with greater craving. This high MOR availability is proposed to be the target of opioid antagonist medication to prevent relapse. However, changes in endogenous opioid tone in AD are poorly characterised and are important to understand as opioid antagonists do not help everyone with AD. We used [11C]carfentanil, a selective MOR agonist positron emission tomography (PET) radioligand, to investigate endogenous opioid tone in AD for the first time. We recruited 13 abstinent male AD and 15 control participants who underwent two [11C]carfentanil PET scans, one before and one 3 h following a 0.5 mg/kg oral dose of dexamphetamine to measure baseline MOR availability and endogenous opioid release. We found significantly blunted dexamphetamine-induced opioid release in 5 out of 10 regions-of-interest including insula, frontal lobe and putamen in AD compared with controls, but no significantly higher MOR availability AD participants compared with HC in any region. This study is comparable to our previous results of blunted dexamphetamine-induced opioid release in gambling disorder, suggesting that this dysregulation in opioid tone is common to both behavioural and substance addictions.

The Analgesic Effect of Transcranial Direct Current Stimulation (tDCS) combined with Physical Therapy on Common Musculoskeletal Conditions: A Systematic Review and Meta-Analysis

BACKGROUND

The analgesic effects of transcranial Direct Current Stimulation (tDCS) combined with physical therapy remain unclear.

OBJECTIVE

To systematically review available evidence comparing tDCS with any physical therapy modality (PTM) to PTM alone or PTM with sham tDCS on pain relief on common musculoskeletal (MSK) conditions, namely knee osteoarthritis (KOA), chronic low back pain (CLBP), myofascial pain syndrome (MPS) and fibromyalgia.

METHODS

EMBASE and MEDLINE were searched from inception to April 2019 for randomized controlled trials. Reviewers independently assessed the studies quality and extracted data according to the PRISMA protocol. The GRADE approach was used to asses quality of evidence and a "Summary of Findings" table was created. The analyses used random-effects model. The primary outcome was pain reduction after treatment.

RESULTS

Eight articles were included. Only one study had low risk of bias. Quality of evidence was considered low or very low. Significant reduction in pain scores were found for fibromyalgia and KOA (Standardized mean difference (SMD) = -1.94 [95% CI: -3.37 to -0.49; I ²=76.4%] and SMD = -2.35 [95% CI: -3.63 to -1.06; I ²=69.7%] respectively). Subgroup analysis considering the type of PTM despite MSK condition revealed significant reduction in pain scores for exercise, SMD = -1.20 [95% CI: -1.683 to -0.717; I ²=10.8%].

CONCLUSIONS

Large heterogeneity and low quality of evidence and limited number of studies were found. Results suggest a potential analgesic effect of tDCS in combination with a PTM for fibromyalgia and KOA. Subgroup analysis suggests a stronger effect of tDCS when combined with an exercise based PTM.

Association between attending exercise-based cardiac rehabilitation and cardiovascular risk factors at one-year post myocardial infarction

Background

Randomized trials confirm the benefits of exercise-based cardiac rehabilitation on cardiovascular risk factors. Whether exercise-based cardiac rehabilitation provides the same favourable effects in real-life cardiac rehabilitation settings, in the modern era of myocardial infarction treatment, is less well known. We examined the association between attending exercise-based cardiac rehabilitation and improvements in cardiovascular risk factors at one-year post myocardial infarction in patients included in the Swedish heart disease registry, SWEDEHEART.

Methods

In this retrospective registry-based cohort study, we included 19 136 patients post myocardial infarction (75% men, 62.8±8.7 years) who were registered in SWEDEHEART between 2011 and 2013. The association between attending exercise-based cardiac rehabilitation (43% participation rate) and changes in cardiovascular risk profile between baseline and one-year follow-up was assessed using multivariable regression analysis adjusting for age, comorbidities and medication.

Results

Attenders more often reported to have stopped smoking (men 64% vs 50%; women 64% vs 53%, p<0.001 for both, only smokers at baseline considered), be more physically active (men 3.9±2.5 vs 3.4±2.7 days/week; women 3.8±2.6 vs 3.0±2.8 days/week, p<0.001 for both) and achieved a slightly larger reduction in triglycerides (men -0.2±0.8 vs -0.1±0.9 mmol/L, p = 0.001; women -0.1±0.6 vs 0.0±0.8 mmol/L, p = 0.01) at one-year compared to non-attenders. Male attenders gained less weight (+0.0±5.7 vs +0.3±5.7 kg, p = 0.01) while female attenders achieved better lipid control (total cholesterol -1.2±1.4 vs -0.9±1.4 mmol/L, p<0.001; low-density lipoprotein -1.2±1.2 vs -0.9 ±1.2 mmol/L, p<0.001) compared to non-attenders.

Conclusions

In an unselected registry cohort of patients post myocardial infarction, compared to non-attenders those attending exercise-based cardiac rehabilitation achieved significantly larger improvements in cardiovascular risk factors at one-year after the acute event.

The different hormonal system during exercise stress coping in horses

The review discusses the hormonal changes during exercise stress. The exercise generally produces a rise of adrenaline (A), noradrenaline (NA), adrenocorticotropic hormone (ACTH), cortisol, glucagon, growth hormone, arginine vasopressine, etc., and a drop of insulin. The hormonal events during reestablishment of homeostasis due to exercise stress can be divided into a catabolic phase, with decreased tolerance of effort, and reversible biochemical, hormonal and immunological changes, and an anabolic phase, with a higher adaptive capacity, and enhanced performance. The two main hormonal axes activated in the catabolic phase are sympathetic–adrenal–medullary system and hypothalamic-pituitary-adrenal (HPA) axis, while in the anabolic phase, growth hormone-insulin-like factor I axis, and gonadal axes. The hormonal responses during exercise and recovery can be regarded as regulatory and integrated endocrine responses. The increase of catecholamines and ACTH is dependent on the intensity of exercise; a marked increase in plasma A occurs during exercises with high emotional content. The response of cortisol is correlated with the duration of exercise, while the effect of exercise duration on b-endorphin changes is highly dependent on the type of exercise performed. Cortisol and b-endorphin changes usually occur in phase, but not during exercises with high emotional content. Glucocorticoids and iodothyronines are involved in meeting immediate energy demands, and a model of functional interactions between HPA axis and hypothalamic-pituitary-thyroid axis during exercise stress is proposed. A modulation of coping responses to different energy demanding physical activities required for sport activities could be hypothesized. This review supports the proposed regulation of hypophysiotropic TRHergic neurons as metabolic integrators during exercise stress. Many hormonal systems (ghrelin, leptin, glucose, insulin, and cortisol) are activated to control substrate mobilizations and utilization. The cardiovascular homeostasis, the fluid and electrolyte balance during exercise are highly dependent on vasoactive hormones (antidiuretic hormone, atrial natriuretic peptide, renin–angiotensin–aldosterone, and prostaglandins) control.

Beneficial Effects of Regular Physical Activity on Exercise-Induced Analgesia in Adolescent Males

PURPOSE

To evaluate exercise-induced analgesia (EIA) effectiveness in healthy adolescent males and to investigate possible associations between EIA and physiological/psychological variables.

METHODS

Twenty-eight healthy adolescent males (14-17 y) participated in this study. EIA was evaluated by comparing perceptions of heat pain stimulations before and after an increasing maximal load test on a cycle ergometer (VO2max).

RESULTS

Pain intensity for mild and strong heat pain stimulations significantly decreased following physical exercise (mild: EIA = 28.6%; 95% confidence interval, 0.9-1.9; P < .001 and strong: EIA = 11.3%; 95% confidence interval, 0.3-1.4; P = .002). The number of physical activity hours per week was positively correlated with the effectiveness of EIA for mild and strong pain intensity (r = .41, P = .03 and r = .43, P = .02, respectively).

CONCLUSIONS

Intense physical exercise decreases perception of intensity of experimental heat pain in healthy adolescent males. The least physically active adolescents have reduced EIA effectiveness to experimental heat pain stimulations compared with physically active ones. Adolescents adopting an active lifestyle have more endogenous pain inhibition and could, therefore, potentially be less disposed to suffer from chronic pain later in life.

Acute and chronic pain in orofacial trauma patients

Trauma or injury to the dentition and supporting tissues is associated with pain and discomfort, as expected, that may present immediately, shortly afterwards, or within a few days. Pain is an essential response to injury because it allows the organism to develop avoidance behavior to potential threats and helps the organism to avoid usage of the injured organ during the healing process. Not only does external trauma induce pain, but also essential invasive dental procedures such as extractions, dental implant insertions, root canal treatments, and oral surgeries are accompanied by similar post-surgical (post-traumatic) pain. The pain intensity after trauma varies and does not always correlate with the extent of injury. Trauma to the orofacial region or the teeth may also indirectly affect and induce pain in other orofacial structures such as the masticatory muscles, the temporomandibular joint, and even the cervical spine. In most cases, the pain will resolve as soon as healing of the affected tissue occurs or after dental and routine palliative treatment. In a limited number of cases, the pain persists beyond healing and evolves into a chronic pain state. Chronic pain in the orofacial region presents diagnostic and management challenges. Misdiagnosis or delayed diagnosis of the oral chronic pain condition may lead to unnecessary dental treatment. This article will discuss diagnosis and treatment for acute and chronic pain as well as potential mechanisms involved in the undesirable transition from acute to chronic pain.

Controlled randomized trial of walking exercise with positive education on cardiovascular fitness and happiness in retired older adults

AIM

Regular walking exercise (RWE) is associated with increased cardiovascular fitness and might elevate subjective psychological well-being. Positive education links positive psychology concepts with self-efficacy through the curriculum, which helps foster well-being. This study examines if regular walking exercise with positive education has better effects on cardiovascular fitness and happiness than RWE alone in retired older adults.

METHODS

Three arms of experimental design were used: pedometer walking exercise training (PWET); positive education and pedometer walking exercise training (PEPWET); and pedometer walking exercise (PWE). Trained walking exercise was provided to the PWET and PEPWET groups by a walking exercise coach three times per week, for 45 min per session for 12 weeks. Positive education was designed and led by a licensed PhD psychologist every other week. Of 150 participants, 60, 60 and 30 were randomly assigned to PWET, PEPWET and PWE, respectively. Demographic information, Chinese Happiness Inventory, RWE, and 6-min walking distance were assessed before and after the intervention.

RESULTS

The percentage of participants who practiced RWE after 12 weeks was significantly higher in the PEPWET group (96.7%), followed by the PWET (75%) and PWE groups (40%). Cardiovascular fitness in the PWET and PEPWET groups was significantly better than in the PWE group. Chinese Happiness Inventory scores in the PWET and PEPWET groups were significantly higher than in the PWE group, and the PEPWET group also showed significantly higher Chinese Happiness Inventory scores than the PWET group.

CONCLUSIONS

In addition to RWE, the study findings show that positive education can be beneficial to promote older adults' RWE, cardiovascular fitness and happiness. Geriatr Gerontol Int 2019; 19: 879-884.

Physical activity as an adjunct treatment for erectile dysfunction

Increasing data are available to suggest that physical activity and lifestyle modification in general can benefit erectile function, with effect sizes comparable with established treatment options such as testosterone therapy and phosphodiesterase type 5 inhibitors. Despite this evidence, primary-care physicians are rarely afforded critical information on the underlying mechanisms through which physical activity works as a treatment, severely hampering treatment credibility for both physician and patient. Physical activity is associated with psychological and metabolic adaptations that are compatible with the adaptations required for the treatment of erectile dysfunction (ED). These adaptations include increased expression and activity of nitric oxide synthase, strengthened endothelial function, acute rises in testosterone, decreased stress and anxiety, and improved body image. Use of physical activity as a first-line treatment option for ED is limited, and explicit physical activity guidelines for the treatment of ED are required. Such guidelines should include not only a suggested exercise programme but also guidelines for physician-patient communication that might enhance patient receptivity and therapy continuation. An understanding of how physical activity affects erectile function, as well as its effectiveness in treating ED compared with other established treatments, can benefit urologists and primary-care physicians searching for noninvasive treatment options for men presenting with poor erectile function.

The Effect of Physical Activity on Cognitive Performance in an Italian Elementary School: Insights From a Pilot Study Using Structural Equation Modeling

When compared to the previous generations, younger generations have become sedentary on a global level. Physical activity positively contributes to human growth and development, causing, indeed, both physiological and psychological benefits. The aim of the current study was examining the relationship between physical activity and school achievement in a sample of 80 Italian elementary (viz. primary) school last year responding children (11.0 ± 0.3 years, 1.46 ± 0.09 m, 39.5 ± 7.9 kg). Such an aim was fulfilled by investigating eventual correlations between physical tests results and school marks and by disclosing eventual mutual relationships between socio-demographics, family context, lifestyle (including physical activity), and school performance information using a structural modeling approach. Children were assessed for lower/upper limbs muscle strength and running/agility performance. Pearson's correlation between physical tests and school performance was studied. We found that agility correlated with English, Italian, mathematics, music, and sport marks, whereas jump correlated with English, mathematics, sport, and technologies marks. Sprint correlated with mathematics, sport, and technologies marks. All correlation coefficients were moderate, except for correlations between sport marks and physical tests (strong correlation). From the structural model, we found that socio-demographics and lifestyle significantly impacted on school achievement. In particular, lifestyle was found to fully moderate the impact of the family context on school achievement. Schools and households represent important settings for improving children physical and psychological-cognitive health and status, offering physical activities opportunities.

Brain Modulation by Electric Currents in Fibromyalgia: A Structured Review on Non-invasive Approach With Transcranial Electrical Stimulation

Fibromyalgia syndrome (FMS) is a complex disorder where widespread musculoskeletal pain is associated with many heterogenous symptoms ranging from affective disturbances to cognitive dysfunction and central fatigue. FMS is currently underdiagnosed and often very poorly responsive to pharmacological treatment. Pathophysiology of the disease remains still obscure even if in the last years fine structural and functional cerebral abnormalities have been identified, principally by neurophysiological and imaging studies delineating disfunctions in pain perception, processing and control systems. On such basis, recently, neurostimulation of brain areas involved in mechanism of pain processing and control (primary motor cortex: M1 and dorsolateral prefrontal cortex: DLPFC) has been explored by means of different approaches and particularly through non-invasive brain stimulation techniques (transcranial magnetic and electric stimulation: TMS and tES). Here we summarize studies on tES application in FMS. The great majority of reports, based on direct currents (transcranial direct currents stimulation: tDCS) and targeting M1, showed efficacy on pain measures and less on cognitive and affective symptoms, even if several aspects as maintenance of therapeutical effects and optimal stimulation parameters remain to be established. Differently, stimulation of DLPFC, explored in a few studies, was ineffective on pain and showed limited effects on cognitive and affective symptoms. Very recently new tES techniques as high-density tDCS (HD-tDCS), transcranial random noise stimulation (tRNS) and tDCS devices for home-based treatment have been explored in FMS with interesting even if very preliminary results opening interesting perspectives for more effective, well tolerated, cheap and easy therapeutic approaches.

Prediction of running-induced Achilles tendinopathy with pain sensitivity - a 1-year prospective study

Background and aims Achilles tendinopathy is common among runners, but the etiology remains unclear. High mechanical pain sensitivity may be a predictor of increased risk of developing Achilles tendinopathy in this group. The purpose of this study was to investigate whether local pain sensitivity could predict the development of Achilles tendinopathy in recreational male runners. The overall hypothesis was that high pain sensitivity would be related to a higher risk of developing Achilles tendinopathy among recreational male runners. Methods Ninety-nine recreational male runners were recruited and followed prospectively for 1 year. At baseline and after 500 km of running the pressure pain threshold (PPT) was assessed at the infraspinatus and at the Achilles tendon (AT-PPT). Based on the AT-PPT at baseline, a median split was used to divide the runners into two groups. The high pain sensitivity groups was defined as runners displaying a pain pressure threshold below 441 kPa on the Achilles tendon, while the low pain sensitivity group was defined as runners displaying a pain pressure threshold above 441 kPa on the Achilles tendon, respectively. Subsequently, the cumulative risk difference between the two groups was assessed by using the pseudo-observation method. Results High pain sensitivity runners sustained 5%-point (95% CI: -0.18 to 0.08) more Achilles tendinopathy episodes during the first 1,500 km. No significant group differences in risk were found at 100, 250, 500, 1,000 and 1,500 km of running. Conclusions No significant association was found between mechanical pain sensitivity in the Achilles tendon and the risk of developing Achilles tendinopathy. However, the risk difference indicated a association between a high mechanical pain sensitivity and an increased risk of developing Achilles tendinopathy. It is plausible that changes in pain sensitivity were masked by unmeasured covariates, such as the differences in progression/regression of training volume and running speed between the two groups. This study was limited in size, which limited the possibility to account for covariates, such as differences in progression/regression of running speed between runners. With the limitations in mind, future studies should control the training volume, speed and running shoes in the design or account for it in the analysis. Implications Pain sensitivity of the Achilles tendon seems not to be related to an increased risk of developing Achilles pain in relation to running.

Prevalence, Wellbeing, and Symptoms of Dysmenorrhea among University Nursing Students in Greece

Dysmenorrhea (pain during menstruation) is one of the most common medical conditions among women of reproductive age. Dysmenorrhea has been studied around the world but not yet in Greece. The aim of the present study was to investigate the prevalence, characteristics, and impact of dysmenorrhea on the wellbeing (exercising, and social and academic functioning) among nursing students in Greece. A cross-sectional study of 637 nursing students was conducted by administering a questionnaire at a university in Athens. The prevalence of dysmenorrhea was 89.2% and the rate of severe intensity was 52.5%. Factors that were associated with severe dysmenorrhea were family history (p = 0.02), early menarche (p = 0.05) and menstruation duration (p = 0.05). Women with moderate and severe pain reported using pain relievers (non-steroidal anti-inflammatory drugs (NSAIDs), paracetamol etc., p < 0.0005). Finally, activities affected by severe pain were class attendance (p = 0.01), personal studying (p < 0.0005), exercising (p < 0.0005), and socializing (p < 0.0005). Exam attendance (p = 0.27) and clinical placement attendance (p = 0.48) were not affected by severe dysmenorrhea. Dysmenorrhea has a high prevalence among nursing students and seems to affect important aspects of wellbeing and academic performance when the pain intensity is severe. The present findings lay the foundation for further investigation of dysmenorrhea both in the Greek population and cross-culturally.

Developing an optimized strategy with transcranial direct current stimulation to enhance the endogenous pain control system in fibromyalgia

INTRODUCTION

Fibromyalgia affects more than 5 million people in the United States and has a detrimental impact on individuals' quality of life. Current pharmacological treatments provide limited benefits to relieve the pain of fibromyalgia, along with a risk of adverse effects; a scenario that explains the increasing interest for multimodal approaches. A tailored strategy to focus on this dysfunctional endogenous pain inhibitory system is transcranial direct current stimulation (tDCS) of the primary motor cortex. By combining tDCS with aerobic exercise, the effects can be optimized. Areas covered: The relevant literature was reviewed and discussed the methodological issues for designing a mechanistic clinical trial to test this combined intervention. Also, we reviewed the neural control of different pathways that integrate the endogenous pain inhibitory system, as well as the effects of tDCS and aerobic exercise both alone and combined. In addition, potential neurophysiological assessments are addressed: conditioned pain modulation, temporal slow pain summation, transcranial magnetic stimulation, and electroencephalography in the context of fibromyalgia. Expert commentary: By understanding the neural mechanisms underlying pain processing and potential optimized interventions in fibromyalgia with higher accuracy, the field has an evident potential of advancement in the direction of new neuromarkers and tailored therapies.

Spinal interleukin-10 produces antinociception in neuropathy through microglial β-endorphin expression, separated from antineuroinflammation

Interleukin 10 (IL-10) is antinociceptive in various animal models of pain without induction of tolerance, and its mechanism of action was generally believed to be mediated by inhibition of neuroinflammation. Here we reported that intrathecal IL-10 injection dose dependently attenuated mechanical allodynia and thermal hyperalgesiain male and female neuropathic rats, with ED₅₀ values of 40.8 ng and 24 ng, and E_max values of 61.5% MPE and 100% MPE in male rats. Treatment with IL-10 specifically increased expression of the β-endorphin (but not prodynorphin) gene and protein in primary cultures of spinal microglia but not in astrocytes or neurons. Intrathecal injection of IL-10 stimulated β-endorphin expression from microglia but not neurons or astrocytes in both contralateral and ipsilateral spinal cords of neuropathic rats. However, intrathecal injection of the β-endorphin neutralizing antibody, opioid receptor antagonist naloxone, or μ-opioid receptor antagonist CTAP completely blocked spinal IL-10-induced mechanical antiallodynia, while the microglial inhibitor minocycline and specific microglia depletor reversed spinal IL-10-induced β-endorphin overexpression and mechanical antiallodynia. IL-10 treatment increased spinal microglial STAT3 phosphorylation, and the STAT3 inhibitor NSC74859 completely reversed IL-10-increased spinal expression of β-endorphin and neuroinflammatory cytokines and mechanical antiallodynia. Silence of the Bcl3 and Socs3 genes nearly fully reversed IL-10-induced suppression of neuroinflammatory cytokines (but not expression of β-endorphin), although it had no effect on mechanical allodynia. In contrast, disruption of the POMC gene completely blocked IL-10-stimulated β-endorphin expression and mechanical antiallodynia, but had no effect on IL-10 inhibited expression of neuroinflammatory cytokines. Thus this study revealed that IL-10 produced antinociception through spinal microglial β-endorphin expression, but not inhibition of neuroinflammation.

Potential approaches to prevent hypoglycemia-associated autonomic failure

Clear health benefits are associated with intensive glucose control in type 1 diabetes mellitus (T1DM). However, maintaining near-normal glycemia remains an elusive goal for many patients, in large part owing to the risk of severe hypoglycemia. In fact, recurrent episodes of hypoglycemia lead to 'hypoglycemia-associated autonomic failure' (HAAF), characterized by defective counter-regulatory responses to hypoglycemia. Extensive studies to understand the mechanisms underlying HAAF have revealed multiple potential etiologies, suggesting various approaches to prevent the development of HAAF. In this review, we present an overview of the literature focused on pharmacological approaches that may prevent the development of HAAF. The purported underlying mechanisms of HAAF include: 1) central mechanisms (opioid receptors, ATP-sensitive K+(KATP) channels, adrenergic receptors, serotonin selective receptor inhibitors, γ-aminobuyric acid receptors, N-methyl D-aspartate receptors); 2) hormones (cortisol, estrogen, dehydroepiandrosterone (DHEA) or DHEA sulfate, glucagon-like peptide-1) and 3) nutrients (fructose, free fatty acids, ketones), all of which have been studied vis-à-vis their ability to impact the development of HAAF. A careful review of the current literature reveals many promising therapeutic approaches to treat or reduce this important limitation to optimal glycemic control.