[Metabolic features of the inflammatory syndrome of chronic pelvic pain (category IIIA of chronic non-bacterial prostatitis) in young men, depending on the somatotype]

PURPOSE

dentification of bioimpedance and clinical features in young men with chronic pelvic pain inflammatory syndrome (CP/CPPS NIH IIIa) depending on the somatotype.

METHOD

s. 150 men of the first period of adulthood from 22 to 35 years old with CP/CPPS NIH IIIa were examined from 2018 to 2022 years. The average age was 31 [28; 34] year. Somatotypes were computed according to Carter and Heath. Body composition was assessed anthropometry and bioimpedance analysis.

RESULTS

Ectomorphs had the least clinical, laboratory and instrumental manifestations of CP/CPPS NIH IIIa, the levels of total and free testosterone were the highest. The active cell mass predominated in the component composition of the body. Manifestations in mesomorphs had a moderate degree of severity. Endomorphs had the most severe manifestations of CP/CPPS NIH IIIa, the largest amount of fat mass was noted in the body composition than in men of other somatotypes, the hormonal status was characterized by the lowest levels of free and total testosterone, and the highest level of estradiol.

DISCUSSION

Based on the literature data and our own results, it can be assumed that the identified changes in the body component composition and hormonal status of men contribute to the maintenance of chronic inflammation in the prostate, organ ischemia, impaired intracranial metabolism, recurrent course of CP/CPPS NIH IIIa, which significantly reduces the patients quality of life and increases the risk of prostate inflammation with age.

CONCLUSION

Determining the somatotype and conducting a component analysis of body composition allows patients to be divided into groups according to the severity of manifestations of CP/CPPS NIH IIIa. The revealed patterns allow us to classify male endomorphs into the group with the most severe manifestations of CP/CPPS NIH IIIa.

Candidate Genes and Proteomic Biomarkers of Serum and Urine in Medication-Overuse Headache

Chronic headache is a topical problem of neurology, psychiatry and general practice. The medication-overuse headache (MOH) is one of the leading pathologies in the structure of chronic headache. However, early diagnosis of the MOH is challenging. We analyzed potential proteomic biomarkers of serum and urine in patients with MOH.

METHODS

We searched PubMed, Springer, Scopus, Web of Science, ClinicalKey, and Google Scholar databases for English publications over the past 10 years using keywords and their combinations.

RESULTS

We found and analyzed seven studies that met the search criteria for the purpose of the review, including 24 serum proteomic biomarkers and 25 urine proteomic biomarkers of MOH. Moreover, the candidate genes and locus of the studied serum (vitamin D-binding protein, lipocalin-type prostaglandin D2 synthase, apolipoprotein E, etc.) and urine proteomic biomarkers (uromodulin, alpha-1-microglobulin, zinc-alpha-2-glycoprotein, etc.) of MOH are presented in this review.

CONCLUSIONS

The serum and urine proteomic biomarkers of MOH can potentially help with the identification of patients with MOH development. Due to the relevance of the problem, the authors believe that further investigation of the MOH proteomic biomarkers in different ethnic and racial groups of patients with primary headache is necessary. In addition, it is important to investigate whether medications of different drug classes influence the levels of serum and urine proteomic biomarkers.

Experimental Chronic Prostatitis/Chronic Pelvic Pain Syndrome Increases Anxiety-Like Behavior: The Role of Brain Oxidative Stress, Serum Corticosterone, and Hippocampal Parvalbumin-Positive Interneurons

Mechanisms of the brain-related comorbidities in chronic prostatitis/chronic pelvic pain syndrome (CP/CPPS) are still largely unknown, although CP/CPPS is one of the major urological problems in middle-aged men, while these neuropsychological incapacities considerably diminish life quality. The objectives of this study were to assess behavioral patterns in rats with CP/CPPS and to determine whether these patterns depend on alterations in the brain oxidative stress, corticosterone, and hippocampal parvalbumin-positive (PV+) interneurons. Adult male Wistar albino rats from CP/CPPS (intraprostatic injection of 3% λ-carrageenan, day 0) and sham (0.9% NaCl) groups were subjected to pain and anxiety-like behavior tests (days 2, 3, and 7). Afterwards, rats were sacrificed and biochemical and immunohistochemical analyses were performed. Scrotal allodynia and prostatitis were proven in CP/CPPS, but not in sham rats. Ethological tests (open field, elevated plus maze, and light/dark tests) revealed significantly increased anxiety-like behavior in rats with CP/CPPS comparing to their sham-operated mates starting from day 3, and there were significant intercorrelations among parameters of these tests. Increased oxidative stress in the hippocampus, thalamus, and cerebral cortex, as well as increased serum corticosterone levels and decreased number of hippocampal PV+ neurons, was shown in CP/CPPS rats, compared to sham rats. Increased anxiety-like behavior in CP/CPPS rats was significantly correlated with these brain biochemical and hippocampal immunohistochemical alterations. Therefore, the potential mechanisms of observed behavioral alterations in CP/CPPS rats could be the result of an interplay between increased brain oxidative stress, elevated serum corticosterone level, and loss of hippocampal PV+ interneurons.

Immune Actions on the Peripheral Nervous System in Pain

Pain can be induced by tissue injuries, diseases and infections. The interactions between the peripheral nervous system (PNS) and immune system are primary actions in pain sensitizations. In response to stimuli, nociceptors release various mediators from their terminals that potently activate and recruit immune cells, whereas infiltrated immune cells further promote sensitization of nociceptors and the transition from acute to chronic pain by producing cytokines, chemokines, lipid mediators and growth factors. Immune cells not only play roles in pain production but also contribute to PNS repair and pain resolution by secreting anti-inflammatory or analgesic effectors. Here, we discuss the distinct roles of four major types of immune cells (monocyte/macrophage, neutrophil, mast cell, and T cell) acting on the PNS during pain process. Integration of this current knowledge will enhance our understanding of cellular changes and molecular mechanisms underlying pain pathogenies, providing insights for developing new therapeutic strategies.

Discovery and validation of biomarkers to aid the development of safe and effective pain therapeutics: challenges and opportunities

Pain medication plays an important role in the treatment of acute and chronic pain conditions, but some drugs, opioids in particular, have been overprescribed or prescribed without adequate safeguards, leading to an alarming rise in medication-related overdose deaths. The NIH Helping to End Addiction Long-term (HEAL) Initiative is a trans-agency effort to provide scientific solutions to stem the opioid crisis. One component of the initiative is to support biomarker discovery and rigorous validation in collaboration with industry leaders to accelerate high-quality clinical research into neurotherapeutics and pain. The use of objective biomarkers and clinical trial end points throughout the drug discovery and development process is crucial to help define pathophysiological subsets of pain, evaluate target engagement of new drugs and predict the analgesic efficacy of new drugs. In 2018, the NIH-led Discovery and Validation of Biomarkers to Develop Non-Addictive Therapeutics for Pain workshop convened scientific leaders from academia, industry, government and patient advocacy groups to discuss progress, challenges, gaps and ideas to facilitate the development of biomarkers and end points for pain. The outcomes of this workshop are outlined in this Consensus Statement.

Plasma protein patterns are strongly correlated with pressure pain thresholds in women with chronic widespread pain and in healthy controls-an exploratory case-control study

Chronic widespread pain (CWP) is a complex pain condition characterized by generalized musculoskeletal pain and often associated with other symptoms. An important clinical feature is widespread increased pain sensitivity such as lowered pain thresholds for mechanical stimuli (pressure pain thresholds [PPT]). There is a growing interest in investigating the activated neurobiological mechanisms in CWP, which includes fibromyalgia. In CWP, strong significant correlations have been found between muscle protein patterns and PPT. This explorative proteomic study investigates the multivariate correlation pattern between plasma proteins and PPT in CWP and in healthy controls (CON). In addition, this study analyses whether the important proteins for PPT differ between the 2 groups.Using 2-dimensional gel electrophoresis, we analyzed the plasma proteome of the CWP (n = 15) and the CON (n = 23) and proteins were identified using mass spectrometry. For both the CWP and the CON, the associations between the identified proteins and PPT were analyzed using orthogonal partial least square in 2 steps.Significant associations between certain plasma proteins and PPT existed both in CWP (R = 0.95; P = .006) and in CON (R = 0.89; P < .001). For both groups of subjects, we found several proteins involved in PPT that reflect different biological processes. The plasma proteins as well as the biological processes involved in PPT differed markedly between the 2 groups of subjects.This study suggests that plasma protein patterns are associated with pain thresholds in CWP. Using the plasma proteome profile of CWP to study potential biomarker candidates could provide a snapshot of ongoing systemic mechanisms in CWP.

Sex Differences in Interleukin-6 Responses Over Time Following Laboratory Pain Testing Among Patients With Knee Osteoarthritis

Epidemiological studies suggest that women are not only at a higher risk for developing knee osteoarthritis (KOA), but also report greater symptom severity compared to men. One potential underlying mechanism of these sex differences may be exaggerated inflammatory responses to pain among women compared to men. The present study examined sex differences in interleukin-6 (IL-6) response over time following experimental pain testing. We hypothesized that women, when compared to men, would show greater IL-6 reactivity when exposed to acute pain in a human laboratory setting. Eighty-four participants (36 men and 48 women) with KOA scheduled for total knee arthroplasty underwent a quantitative sensory testing (QST) battery. A total of seven IL-6 measurements were taken, twice at baseline, once immediately after QST, and every 30 minutes up to 2 hours after QST. Consistent with our hypothesis, women, when compared to men, showed accelerated increases in IL-6 levels following laboratory-evoked pain, even after controlling for body mass index, marital status, clinical pain, evoked pain sensitivity, and situational pain catastrophizing. Given that KOA is a chronic condition, and individuals with KOA frequently experience pain, these sex differences in IL-6 reactivity may contribute to the maintenance and/or exacerbation of KOA symptoms. PERSPECTIVES: The present study demonstrates that women, when compared to men, exhibit greater IL-6 reactivity after exposure to laboratory-evoked pain. Such sex differences may explain the mechanisms underlying women's higher chronic pain risk and pain perception, as well as provide further insight in developing personalized pain interventions.

The effect of vitamin D replacement on spinal inhibitory pathways in women with chronic widespread pain

Vitamin D replacement helps in pain reduction in patients with chronic widespread pain (CWP). But the current literature lack studies that investigate its mechanism. Cutaneous silent period (CSP) is the electrophysiologic analog of the spinal inhibitory pathways and an objective method to document their involvement. This study aims to show if vitamin D replacement has an effect on the spinal inhibitory pathways through CSP parameters. Female patients who have CWP with vitamin D deficiency were included. Patients received an 8-week replacement therapy of vitamin D. Patients' pain were evaluated using the visual analog scale (VAS) and Leeds assessment of neuropathic symptoms and signs pain scale (LANSS). Quality of life with Nottingham Health Profile (NHP) and CSP parameters were also recorded before and after treatment. A total of 51 patients were included in the final analyses. The mean age of the patients was 44.3 ± 12.7 (minimum 18-maximum 65). Mean symptom duration was 13.1 ± 6.7 (minimum3-maximum 24) months. Patients' mean BMI was 21.6 ± 3.9 (minimum 18.0 maximum 29.1). Patients' median VAS and LANSS scores decreased significantly (p < 0.01) and NHP scores improved significantly in all subsets (p < 0.01). Vitamin D replacement did not significantly change CSP latency and duration (p = 0.06 and p = 0.12).Vitamin D replacement does not seem to work via modifying the spinal inhibitory pathways that are involved in the formation of the cutaneous silent period. This is the first study to objectively investigate the effect of vitamin D replacement on central sensitization mechanisms.

Enrichment of genomic pathways based on differential DNA methylation profiles associated with chronic musculoskeletal pain in older adults: An exploratory study

Our study aimed to identify differentially methylated CpGs/regions and their enriched genomic pathways associated with underlying chronic musculoskeletal pain in older individuals. We recruited cognitively healthy older adults with (n = 20) and without (n = 9) self-reported musculoskeletal pain and collected DNA from peripheral blood that was analyzed using MethylationEPIC arrays. We identified 31,739 hypermethylated CpG and 10,811 hypomethylated CpG probes (ps ≤ 0.05). All CpG probes were clustered into 5966 regions, among which 600 regions were differentially methylated at p ≤ 0.05 level, including 294 hypermethylated regions and 306 hypomethylated regions (differentially methylated regions). Ingenuity pathway enrichment analysis revealed that the pain-related differentially methylated regions were enriched across multiple pathways. The top 10 canonical pathways were linked to cellular signaling processes related to immune responses (i.e. antigen presentation, programed cell death 1 receptor/PD-1 ligand 1, interleukin-4, OX40 signaling, T cell exhaustion, and apoptosis) and gamma-aminobutyric acid receptor signaling. Further, Weighted Gene Correlation Network Analysis revealed a comethylation network module in the pain group that was not preserved in the control group, where the hub gene was the cyclic adenosine monophosphate-dependent transcription factor ATF-2. Our preliminary findings provide new epigenetic insights into the role of aberrant immune signaling in musculoskeletal pain in older adults while further supporting involvement of dysfunctional GABAergic signaling mechanisms in chronic pain. Our findings need to be urgently replicated in larger cohorts as they may serve as a basis for developing and targeting future interventions.

An Analysis of Biomarkers in Patients with Chronic Pain

BACKGROUND

Because of the subjective nature of current pain assessments, limited efficacy of treatment options and risks associated with opioid abuse and diversion, the need for objective data to assist with chronic pain management has never been greater. Successful identification of mechanistic biomarkers would not only improve our understanding and ability to accurately diagnose pain disorders but would also facilitate the development of disease-modifying pain drugs.

OBJECTIVES

The objective of this study was to determine and evaluate the prevalence of abnormal biomarker findings in a population of patients with chronic pain.

STUDY DESIGN

Retrospective, observational study.

SETTING

Data analysis of biomarker test results was performed at a single industry site (Ethos Research & Development, Newport, KY) from clinical samples collected and analyzed from July to December 2018.

METHODS

A novel, pain-specific biomarker test panel that evaluates biomarkers of systemic inflammation, oxidative stress, neurotransmitter turnover, and micronutrient status was employed to determine the prevalence of abnormal findings in 17,834 unique patient samples analyzed at a national reference laboratory (Ethos Laboratories, Newport, KY). Patient biomarker results were considered abnormal if they were outside of the 95% confidence interval reference ranges established using a healthy population of donors who had no history of chronic pain or opioid use.

RESULTS

A total of 77% of patients with chronic pain exhibited at least one abnormal biomarker result (n = 13,765). The most common abnormal biomarker finding was elevated quinolinic acid, which was observed in 29% of patients (n = 5,107). Elevated pyroglutamate, indicative of glutathione depletion, was observed in 19% of patients (n = 3,314). Elevated xanthurenic acid, indicative of vitamin B6 insufficiency, was observed in 17% of patients (3,025). Elevated levels of the acrolein metabolite 3-hydroxypropyl mercapturic acid were observed in 21% of patients (n = 3,667). Elevated methylmalonic acid, indicative of a vitamin B12 deficiency, was observed in 10% of patients (n = 1,827), whereas abnormally low levels of neurotransmitter metabolites were observed in 8% of patients (n = 1,456).

LIMITATIONS

Medications and/or conditions other than those associated with chronic pain were not evaluated as potential causes of abnormal biomarker findings.

CONCLUSIONS

A novel biomarker assay that measures objective correlates to the neurobiological processes underlying chronic pain reveals a high prevalence of atypical biochemistry in a population of patients with pain. Abnormal biomarker findings presented here provide objective support for the role of cytokine-mediated inflammation, oxidative stress, abnormally low production of neurotransmitters, and micronutrient deficiencies in the development or worsening of chronic pain. This unique panel of functional pain biomarkers provides practitioners with novel, objective insight into the underlying causes of pain, which will pave the way for truly personalized pain medicine. Correcting abnormal biomarker findings with targeted, nonopioid therapies to improve patient function and alleviate pain potentially could lessen the opioid burden and drastically reduce health care costs.

KEY WORDS

Biomarker, pain, inflamation, oxidative stress, neurotransmitter, micronutrient deficiency, Kynurenine Pathway.

Nonspecific Low Back Pain: Inflammatory Profiles of Patients With Acute and Chronic Pain

BACKGROUND

The pathogenesis of low back pain (LBP) remains unclear. However, recent studies suggest that the inflammatory response may be inherent in spinal pain. The purpose of this study was to discern inflammatory profiles in patients with nonspecific acute and chronic LBP in relation to those in asymptomatic individuals.

MATERIALS AND METHODS

Peripheral blood samples were obtained from asymptomatic controls and patients with nonspecific acute and chronic LBP reporting a minimum pain score of 3 on a 10-point Visual Analogue Scale (VAS). The levels of in vitro production of proinflammatory (tumor necrosis factor α [TNFα], interleukin [IL] 1β, IL-6, IL-2, interferon γ) and anti-inflammatory (IL-1 receptor antagonist, soluble receptors of TNF2, and IL-10) mediators were determined by specific immunoassays.

RESULTS

The mean VAS scores were comparable between the acute and chronic LBP patient groups. Compared with asymptomatic group, the production of TNFα, IL-1β, IL-6 and their ratios to IL-10 levels were significantly elevated in both patient groups (P=0.0001 to 0.003). In acute LBP group, the ratio of IL-2:IL-10 was also significantly increased (P=0.02). In contrast, the production of interferon γ was significantly reduced compared with the other study groups (P=0.005 to 0.01), nevertheless, it was positively correlated (P=0.006) with pain scores. In chronic LBP patients, the production of TNFα, IL-1 receptor antagonist, and soluble receptors of TNF2 was significantly increased (P=0.001 to 0.03) in comparison with the control and acute LBP groups, and TNFα and IL-1β levels were positively correlated (P<0.001) with VAS scores.

CONCLUSIONS

The inflammatory profiles of patients with acute and chronic LBP are distinct. Nonetheless, in both patient groups, an imbalance between proinflammatory and anti-inflammatory mediator levels favors the production of proinflammatory components.

Vaginal Diazepam for Nonrelaxing Pelvic Floor Dysfunction: The Pharmacokinetic Profile

BACKGROUND

Vaginal diazepam is frequently used to treat pelvic floor tension myalgia and pelvic pain despite limited knowledge of systemic absorption.

AIM

To determine the pharmacokinetic and adverse event profile of diazepam vaginal suppositories.

METHODS

We used a prospective pharmacokinetic design with repeated assessments of diazepam levels. Eight healthy volunteers were administered a 10-mg compounded vaginal diazepam suppository in the outpatient gynecologic clinic. Serum samples were collected at 0, 45, 90, 120, and 180 minutes; 8, 24, and 72 hours; and 1 week following administration of a 10-mg vaginal suppository. The occurrence of adverse events was assessed using the alternate step and tandem walk tests, the Brief Confusion Assessment Method, and numerical ratings. Plasma concentrations of diazepam and active long-acting metabolites were measured. Pharmacokinetic parameters were calculated by standard noncompartmental methods.

RESULTS

The mean peak diazepam concentration (C_max) of 31.0 ng/mL was detected at a mean time (T_max) of 3.1 hours after suppository placement. The bioavailability was found to be 70.5%, and the mean terminal elimination half-life was 82 hours. The plasma levels of temazepam and nordiazepam peaked at 0.8 ng/mL at 29 hours and 6.4 ng/mL at 132 hours, respectively. Fatigue was reported by 3 of 8 participants.

CLINICAL IMPLICATIONS

Serum plasma concentrations of vaginally administered diazepam are low; however the half-life is prolonged.

STRENGTHS & LIMITATIONS

Strengths include use of inclusion and exclusion criteria aimed at mitigating clinical factors that could adversely impact diazepam absorption and metabolism, and the use of an ultrasensitive LC-MS/MS assay. Limitations included the lack of addressing the efficacy of vaginal diazepam in lieu of performing a pure pharmacokinetic study with healthy participants.

CONCLUSION

Vaginal administration of diazepam results in lower peak serum plasma concentration, longer time to peak concentration, and lower bioavailability than standard oral use. Providers should be aware that with diazepam's long half-life, accumulating levels would occur with chronic daily doses, and steady-state levels would not be reached for up to 1 week. This profile would favor intermittent use to allow participation in physical therapy and intimacy. Larish AM, Dickson RR, Kudgus RA, et al. Vaginal Diazepam for Nonrelaxing Pelvic Floor Dysfunction: The Pharmacokinetic Profile. J Sex Med 2019;16;763-766.

Association between serum 25-hydroxyvitamin D levels and self-reported chronic pain in older adults: A cross-sectional analysis from the ViDA study

Chronic pain is a major contributor to the global burden of disability. Prior studies on the association between serum 25-hydroxyvitamin D (25(OH)D) levels and chronic pain have yielded mixed results. The Vitamin D Assessment study, a large randomized controlled trial from New Zealand, offered the opportunity to examine this association in data collected at baseline in all participants, and among those with arthritis or depression. A total of 5110 participants aged 50-84 years were recruited from community general practices. Chronic pain (lasting ≥6 months) and other baseline characteristics were collected at baseline interview. Serum 25(OH)D concentration was measured by liquid chromatography-tandem mass spectrometry. Associations between 25(OH)D levels and chronic pain were explored using multivariable log-binomial regression to estimate relative risks (RRs). Out of 5049 participants with complete data, 871 (17%) reported having this clinical outcome, and 1254 (25%) had a 25(OH)D concentration <50 nmol/L. There was no significant association between 25(OH)D and chronic pain, with vitamin D status categorized in four groups: <25.0, 25.0-49.9, 50.0-74.9, and ≥75.0 nmol/L (the highest group as reference). The unadjusted RRs were 1.09, 1.10, and 1.08, respectively (P_trend = 0.24). Adjustment for demographics, lifestyle, BMI, medical history, prescription of analgesics and vitamin D supplements did not change this finding. Similar non-significant results were observed in participants with arthritis (n = 1732) or depression (n = 528). In this multi-ethnic, community-selected sample of older adults in New Zealand, serum 25(OH)D levels were not associated with chronic pain. These results do not support a role for low vitamin D status in the prevalence of chronic pain in older adults.

Secondary adrenal insufficiency and pituitary dysfunction in oral/transdermal opioid users with non-cancer pain

Objective To evaluate pituitary function, sexual function and quality of life (QoL) in patients on oral or transdermal opioids. Design and methods Cross-sectional study comparing pituitary function, QoL and sexual function in people on long-term opioid therapy (n = 40) vs an age- and sex-matched control group (n = 25). Baseline pituitary function was assessed on blood samples collected prior to 0900 h. Further testing with corticotropin (250 µg IV) and metyrapone (30 mg/kg) stimulation tests was undertaken on participants with serum cortisol <250 nmol/L. Validated questionnaires completed to assess QoL, fatigue and sexual function. Results Secondary adrenal insufficiency (SAI) was identified on the basis of a failed stimulation test in 22.5% of opioid users vs no controls (P = 0.01). Opioid users with SAI had a higher median morphine-equivalent daily dose (MEDD), P = 0.037 - 50% with MEDD >200 mg and 0% with MEDD <60 mg had SAI. Among male participants, testosterone was inversely associated with BMI (P = 0.001) but not opioid use. A non-significant trend to low testosterone <8 nmol/L in male opioid users (11/24 opioid users vs 2/14 control, P = 0.08) suggests a small subgroup with opioid-induced androgen deficiency. Opioid users had greater fatigue, reduced quality of life in all subsections of the SF-36 and impaired sexual function in both males and females (all scores P < 0.001 compared to controls). Conclusion Long-term opioid therapy was associated with dose-related SAI in over 20% of chronic pain patients and is associated with poor quality of life, fatigue and sexual dysfunction. Obesity confounds the interpretation of opioid-induced male androgen deficiency.

Increased Central Nervous System Interleukin-8 in a Majority Postlaminectomy Syndrome Chronic Pain Population

Background and Objectives

Multiple processes have been identified as potential contributors to chronic pain, with increasing evidence illustrating an association with aberrant levels of neuroimmune mediators. The primary objectives of the present study were to examine central nervous system cytokines, chemokines, and growth factors present in a chronic pain population and to explore patterns of the same mediator molecules over time. Secondary objectives explored the relationship of central and peripheral neuroimmune mediators while examining the levels of anxiety, depression, sleep quality, and perception of pain associated with the chronic pain patient experience.

Methods

Cerebrospinal fluid (CSF) from a population of majority postlaminectomy syndrome patients (N = 8) was compared with control CSF samples (N = 30) to assess for significant differences in 10 cytokines, chemokines, and growth factors. The patient population was then followed over time, analyzing CSF, plasma, and psychobehavioral measures.

Results

The present observational study is the first to demonstrate increased mean CSF levels of interleukin-8 (IL-8; P < 0.001) in a small population of majority postlaminectomy syndrome patients, as compared with a control population. Over time in pain patients, CSF levels of IL-8 increased significantly (P < 0.001).

Conclusions

These data indicate that IL-8 should be further investigated and psychobehavioral components considered in the overall chronic pain paradigm. Future studies examining the interactions between these factors and IL-8 may identify novel targets for treatment of persistent pain states.

Metabolomic markers of fatigue: Association between circulating metabolome and fatigue in women with chronic widespread pain

BACKGROUND

Fatigue is a sensation of unbearable tiredness that frequently accompanies chronic widespread musculoskeletal pain (CWP) and inflammatory joint disease. Its mechanisms are poorly understood and there is a lack of effective biomarkers for diagnosis and onset prediction. We studied the circulating metabolome in a population sample characterised for CWP to identify biomarkers showing specificity for fatigue.

MATERIAL AND METHODS

Untargeted metabolomic profiling was conducted on fasting plasma and serum samples of 1106 females with and without CWP from the TwinsUK cohort. Linear mixed-effects models accounting for covariates were used to determine relationships between fatigue and metabolites. Receiver operating curve (ROC)-analysis was used to determine predictive value of metabolites for fatigue.

RESULTS

While no association between fatigue and metabolites was identified in twins without CWP (n=711), in participants with CWP (n=395), levels of eicosapentaenoate (EPA) ω-3 fatty acid were significantly reduced in those with fatigue (β=-0.452±0.116; p=1.2×10-4). A significant association between fatigue and two other metabolites also emerged when BMI was excluded from the model: 3-carboxy-4-methyl-5-propyl-2-furanpropanoate (CMPF), and C-glycosyltryptophan (p=1.5×10-4 and p=3.1×10-4, respectively). ROC analysis has identified a combination of 15 circulating metabolites with good predictive potential for fatigue in CWP (AUC=75%; 95% CI 69-80%).

CONCLUSION

The results of this agnostic metabolomics screening show that fatigue is metabolically distinct from CWP, and is associated with a decrease in circulating levels of EPA. Our panel of circulating metabolites provides the starting point for a diagnostic test for fatigue in CWP.

Validation of standard operating procedures in a multicenter retrospective study to identify -omics biomarkers for chronic low back pain

Chronic low back pain (CLBP) is one of the most common medical conditions, ranking as the greatest contributor to global disability and accounting for huge societal costs based on the Global Burden of Disease 2010 study.

Large genetic and -omics studies provide a promising avenue for the screening, development and validation of biomarkers useful for personalized diagnosis and treatment (precision medicine). Multicentre studies are needed for such an effort, and a standardized and homogeneous approach is vital for recruitment of large numbers of participants among different centres (clinical and laboratories) to obtain robust and reproducible results. To date, no validated standard operating procedures (SOPs) for genetic/-omics studies in chronic pain have been developed.

In this study, we validated an SOP model that will be used in the multicentre (5 centres) retrospective “PainOmics” study, funded by the European Community in the 7th Framework Programme, which aims to develop new biomarkers for CLBP through three different -omics approaches: genomics, glycomics and activomics.

The SOPs describe the specific procedures for (1) blood collection, (2) sample processing and storage, (3) shipping details and (4) cross-check testing and validation before assays that all the centres involved in the study have to follow.

Multivariate analysis revealed the absolute specificity and homogeneity of the samples collected by the five centres for all genetics, glycomics and activomics analyses.

The SOPs used in our multicenter study have been validated. Hence, they could represent an innovative tool for the correct management and collection of reliable samples in other large-omics-based multicenter studies.

[Histamine metabolism disorder in pathogenesis of chronic pelvic pain in patients with external genital endometriosis]

Objective. To study features of histamine metabolism in patients with chronic pelvic pain associated with external genital endometriosis. Methods. For quantitative assessment of histamine level in peripheral blood was taken from 100 patients which than was centrifuged. In blood serum histamine concentration was determined by enzyme-linked immunosorbent assay method with reagents «Histamine ЕLISA» on the machine BAE-1000 Histamine (Labor Diagnostika Nord - LDN, Hermany). A pain syndrome was assessed by Visual Analog Scale (VAS), quality of life assessment - by Endometriosis Health Profile Questionnaire (EHR-30), level of anxiety was determined by Spielberger-Khanin questionnaire. The results. Showed statistically higher histamine level in patients with severe pain according to VAS. After assessment of results obtained from Spielberger-Khanin questionnaire 100% experimental group's women with external genital endometriosis (n = 60) were noted to be have high level of state and trait anxiety, then 40% women of control group (n = 16) have moderate level of anxiety. The incidence of depression in women with chronic pelvic pain was 58.3% (n = 35) and the main part (n = 20) were women with severe stage of pelvic pain according to VAS. Conclusions. Psycho emotional condition of women with external genital endometriosis associated pelvic pain characterized by higher depression and anxiety levels, with significant decrease quality of life. Direct relationship also was found between pain syndrome intensity and histamine level in peripheral blood in patients with external genital endometriosis.

Signs of ongoing inflammation in female patients with chronic widespread pain: A multivariate, explorative, cross-sectional study of blood samples

This cross-sectional study investigates the plasma inflammatory profile of chronic widespread pain (CWP) patients compared to healthy controls (CON). Rather than analyzing a relatively few substances at a time, we used a new multiplex proximity extension assay (PEA) panel that enabled the simultaneous analysis of 92 inflammation-related proteins, mainly cytokines and chemokines.Seventeen women with CWP and 21 female CON participated and a venous blood sample was drawn from all subjects. Pain intensity and pain thresholds for pressure, heat, and cold were registered. A PEA panel (92 proteins) was used to analyze the blood samples. Multivariate data analysis by projection was used in the statistical analyses.Eleven proteins significantly differentiated the CON and CWP subjects (R = 0.58, Q = 0.37, analysis of variance of cross-validated predictive residuals P = 0.006). It was not possible to significantly regress pain thresholds within each group (CON or CWP). Positive significant correlations existed between several proteins and pain intensities in CWP, but the model reliability of the regression was poor.CWP was associated with systemic low-grade inflammation. Larger studies are needed to confirm the results and to investigate which alterations are condition-specific and which are common across chronic pain conditions. The presence of inflammation could promote the spreading of pain, a hallmark sign of CWP. As it has been suggested that prevalent comorbidities to pain (e.g., depression and anxiety, poor sleep, and tiredness) also are associated with inflammation, it will be important to determine whether inflammation may be a common mediator.

'Omics' biomarkers associated with chronic low back pain: protocol of a retrospective longitudinal study

INTRODUCTION

Chronic low back pain (CLBP) produces considerable direct costs as well as indirect burdens for society, industry and health systems. CLBP is characterised by heterogeneity, inclusion of several pain syndromes, different underlying molecular pathologies and interaction with psychosocial factors that leads to a range of clinical manifestations. There is still much to understand in the underlying pathological processes and the non-psychosocial factors which account for differences in outcomes. Biomarkers that may be objectively used for diagnosis and personalised, targeted and cost-effective treatment are still lacking. Therefore, any data that may be obtained at the '-omics' level (glycomics, Activomics and genome-wide association studies-GWAS) may be helpful to use as dynamic biomarkers for elucidating CLBP pathogenesis and may ultimately provide prognostic information too. By means of a retrospective, observational, case-cohort, multicentre study, we aim to investigate new promising biomarkers potentially able to solve some of the issues related to CLBP.

METHODS AND ANALYSIS

The study follows a two-phase, 1:2 case-control model. A total of 12 000 individuals (4000 cases and 8000 controls) will be enrolled; clinical data will be registered, with particular attention to pain characteristics and outcomes of pain treatments. Blood samples will be collected to perform -omics studies. The primary objective is to recognise genetic variants associated with CLBP; secondary objectives are to study glycomics and Activomics profiles associated with CLBP.

ETHICS AND DISSEMINATION

The study is part of the PainOMICS project funded by European Community in the Seventh Framework Programme. The study has been approved from competent ethical bodies and copies of approvals were provided to the European Commission before starting the study. Results of the study will be reviewed by the Scientific Board and Ethical Committee of the PainOMICS Consortium. The scientific results will be disseminated through peer-reviewed journals.

TRIAL REGISTRATION NUMBER

NCT02037789; Pre-results.

No association between level of vitamin D and chronic low back pain in Swedish primary care: a cross-sectional case-control study

OBJECTIVE

Assessment of vitamin D levels and deficiency status in individuals with chronic low back pain (CLBP) in a Swedish general population, compared with controls matched for sex and age.

DESIGN

Cross-sectional case-control study.

SETTING

Primary care, southern Sweden.

SUBJECTS

Participants (n = 44) with self-reported low back pain for at least 3 months and individually sex- and age-matched controls without a chronic pain condition (n = 44), recruited from the general population by random letter of invitation.

MAIN OUTCOME MEASURE

Association between vitamin D level and CLBP when adjusting for possible confounders in a multivariate forward conditional logistic regression model.

RESULTS

Mean S-25-hydroxyvitamin D levels were 81 and 80 nmol/L in the CLBP and control group, respectively. The prevalence of vitamin D deficiency was low and similar in the CLBP group and the control group. Vitamin D level was not associated with CLBP when potential confounders were taken into account.

CONCLUSIONS

No difference in vitamin D levels between participants with CLBP and matched controls could be demonstrated in the present sample. Assessment of vitamin D level and deficiency status may be of questionable value in the management of CLBP in primary care settings at similar latitudes, unless there are additional risk factors for deficiency or specific indicators of osteomalacia. Key points Vitamin D deficiency is common and reported in many chronic pain conditions, including chronic low back pain (CLBP), but evidence for an association and causality is insufficient. • The present study found no association between vitamin D levels and CLBP in a case-control sample of 44 + 44 individuals from the Swedish general population. • Prevalence of vitamin D deficiency was low and comparable in individuals with CLBP and controls without chronic pain, matched for sex and age. • Assessment of vitamin D status, for the purpose of finding and treating an underlying cause of pain, may be of limited value in the management of CLBP in primary care settings at similar latitudes.

Differential expression of P2X7 receptor and IL-1β in nociceptive and neuropathic pain

BACKGROUND

Despite substantial progress, pathogenesis and therapy of chronic pain are still the focus of many investigations. The ATP-gated P2X7 receptor (P2X7R) has previously been shown to play a central role in animal models of nociceptive inflammatory and neuropathic pain. Recently, we found that the adaptive immune system is involved in the pathophysiology of chronic nociceptive and neuropathic pain in humans. So far, data regarding P2X7R expression patterns on cells of the adaptive immune system of pain patients are scarce. We therefore analyzed the P2X7R expression on peripheral blood lymphocytes and monocytes, as well as serum levels of IL-1β in patients suffering from chronic nociceptive and neuropathic pain in comparison to healthy volunteers in order to identify individuals who might benefit from a P2X7R modulating therapy.

METHODS

P2X7R messenger RNA (mRNA) and protein expression were determined in patients with either chronic nociceptive low back pain (CLBP) or neuropathic pain (NeP), and in healthy volunteers by quantitative real-time PCR (qPCR) and by fluorescence-assisted cell-sorting (FACS), respectively. IL-1β serum levels were measured with a multiplex cytokine assay.

RESULTS

Compared to healthy volunteers, P2X7R mRNA (1.6-fold, p = 0.038) and protein levels were significantly increased on monocytes (NeP: 24.6 ± 6.2, healthy volunteers: 17.0 ± 5.4; p = 0.002) and lymphocytes (NeP: 21.8 ± 6.5, healthy volunteers: 15.6 ± 5.2; p = 0.009) of patients with NeP, but not in patients with CLBP. Similarly, IL-1β serum concentrations were significantly elevated only in NeP patients (1.4-fold, p = 0.04).

CONCLUSIONS

A significant upregulation of P2X7R and increased IL-1β release seems to be a particular phenomenon in patients with NeP. P2X7R inhibitors may therefore represent a potential option for the treatment of this frequently intractable type of pain. German Clinical Trial Register (DRKS): Registration Trial DRKS00005954.

Diagnosis of endometriosis in women with chronic pelvic pain

PURPOSE OF INVESTIGATION

To assess the accuracy of CA-125 determination associated with clinical history and of the neutrophil/lymphocyte (N/L) ratio for a presumptive diagnosis of endometriosis in women with chronic pelvic pain (CPP).

MATERIALS AND METHODS

This was a cross-sectional study of data from the medical records of women with CPP submitted to laparoscopy from August 1999 to January 2009 at the University Hospital. The performance of the evaluation of CA-125 and of the N/L ratio for the prediction of endometriosis was compared based on the corresponding ROC curves and their 95% confidence intervals.

RESULTS

CA-125 levels were significantly higher in women with CPP and endometriosis and their association with a complaint of dysmenorrhea improved their sensitivity. For a cut-off of 20 IU/ml, the predictive value for a diagnosis of endometriosis in women with CPP was 97.6%. Dyspareunia, subfertility, and N/L ratio were not useful for a diagnosis of endometriosis in women with CPP.

CONCLUSION

The association of elevated CA-125 levels with a complaint of dysmenorrhea is adequate in a presumptive and accurate diagnosis of endometriosis in this specific group of women with CPP, permitting an early institution of clinical treatment without the need of previous laparoscopic confirmation.

The Association between Chronic Widespread Musculoskeletal Pain, Depression and Fatigue Is Genetically Mediated

BACKGROUND

Chronic widespread muscoloskeletal pain (CWP) is prevalent in the general population and associated with high health care costs, so understanding the risk factors for chronic pain is important for both those affected and for society. In the present study we investigated the underlying etiological structure of CWP to understand better the association between the major clinical features of fatigue, depression and dihydroepiandrosterone sulphate (DHEAS) using a multivariate twin design.

METHODOLOGY/PRINCIPLE FINDINGS

Data were available in 463 UK female twin pairs including CWP status and information on depression, chronic fatigue and serum DHEAS levels. High to moderate heritabilities for all phenotypes were obtained (42.58% to 74.24%). The highest phenotypic correlation was observed between fatigue and CWP (r = 0.45), and the highest genetic correlation between CWP and fatigue (rg = 0.78). Structural equation modeling revealed the AE Cholesky model to provide the best model of the observed data. In this model, two additive genetic factors could be detected loading heavily on CWP-A2 explaining 40% of the variance and A3 20%. The factor loading heaviest on DHEAS showed only a small loading on the other phenotypes and none on fatigue at all. Furthermore, one distinct non-shared environmental factor loading specifically on CWP-but not on any of the other phenotypes-could be detected suggesting that the association between CWP and the other phenotypes is due only to genetic factors.

CONCLUSIONS/SIGNIFICANCE

Our results suggest that CWP and its associated features share a genetic predisposition but that they are relatively distinct in their environmental determinants.

The effects of black soybean (Glycine max var.) on chronic cervical pain of sedentary office workers in a northern Chinese population

Chronic cervical pain is a common symptom of sedentary office workers. Black soybean (Glycine max var.) has rich necessary nutrients for the therapy of chronic pain. Thus, it may ease chronic cervical pain. To prove our claim, 260 sedentary office workers with chronic pain were recruited and they consumed the defined diets at breakfast, lunch, and dinner with 1 g, 5 g and 10 g (3 g, 15 g, 30 g daily) cooked black soybean for 24 weeks. Visual analog scale (VAS), neck disability index (NDI) pain scores and short-form 36 (SF-36) health survey questionnaires were applied in the study. The levels of N-methyl-D-aspartate receptors (NMDAR) were measured. The VAS and NDI pain scores reduced and SF-36 scores increased in a 15 or 30 g black soybean daily group compared with a 3 g black soybean daily group after a 24-week therapy (P < 0.05). The 30 g black soybean daily group was better than the 15 g black soybean daily group in relieving chronic cervical pain of sedentary office workers (p < 0.05). The levels of NMDAR were lower in the 15 or 30 black soybean daily group than those in the 3 g black soybean daily group (P < 0.05). Black soybean can ameliorate chronic cervical pain by down-regulating the levels of NMDAR.

[THE ROLE OF OSTEOCALCIN IN COURSE OF OSTEOARTHRITIS AND TYPE 2 DIABETES MELLITUS]

We studied the level of osteocalcin and its relationships with carbohydrate metabolism and clinical and radiographic changes in patients with osteoarthritis (OA) and type 2 diabetes mellitus (DM 2) and their combination. Significant negative correlation between the level of osteocalcin and carbohydrate metabolism, and clinical and radiographic changes in patients with OA and DM 2 was found. We determined, that negative correlation of osteocalcin with carbohydrate metabolism and radiographic changes, and more pronounced pain in OA maybe an indication that the lack of production of osteocalcin leads to more severe changes during the OA on the background of DM 2 diabetes mellitus.

[THE APPLICATION OF ANTIHOMOTOXIC DRUG PREPARATIONS IN THE COMPLEX TREATMENT IN PATIENTS WITH NEUROLOGICAL MANIFESTATIONS OF LUMBAR OSTEOCHONDROSIS]

The expediency of application homeosyniatry by preparations of Traumel S and Placenta Compositum after the offered chart in relation to a complex with classic acupuncture and in relation to the group of the generally accepted treatment has been proved in complex treatment patients with reflex syndromes of lumbar osteochondrosis. A similar conclusion was done after the statistically reliable (P < 0.05) dynamics of parameters of endogenous intoxication, liperoxydation and antioxydant systems of the protection (by the level of katalase, superoxyddismutase, SH-groups, ceruloplasmine).

Musculoskeletal Pain, Self-reported Physical Function, and Quality of Life in the Teen-Longitudinal Assessment of Bariatric Surgery (Teen-LABS) Cohort

IMPORTANCE

Obesity is associated with chronic musculoskeletal pain and is a risk factor for disability and osteoarthritis.

OBJECTIVES

To describe the prevalence, sites, and intensity of musculoskeletal pain in adolescents with severe obesity; to evaluate associations between musculoskeletal pain and self-reported physical function as well as weight-related quality of life; and to evaluate the association between musculoskeletal pain and high-sensitivity C-reactive protein level.

DESIGN, SETTING, AND PARTICIPANTS

Teen-Longitudinal Assessment of Bariatric Surgery (Teen-LABS) is a prospective, observational study that collects standardized data on adolescents undergoing weight loss surgery at 5 US centers. We examined baseline data from this cohort between February 28, 2007, and December 30, 2011. We excluded adolescents with Blount disease and slipped capital femoral epiphyses. A total of 233 participants were included in these analyses.

MAIN OUTCOMES AND MEASURES

We assessed musculoskeletal pain and pain intensity of the lower back, hips, knees, and ankles/feet using the visual analog scale, categorizing musculoskeletal pain into lower back pain, lower extremity (hips, knees, and feet/ankles combined) pain, and no pain. We assessed self-reported physical function status with the Health Assessment Questionnaire Disability Index and assessed weight-related quality of life with the Impact of Weight on Quality of Life-Kids measure. We adjusted for sex, race, age at surgery, body mass index (BMI; calculated as weight in kilograms divided by height in meters squared), and clinical depressive symptoms in regression analyses.

RESULTS

Among the 233 participants, the mean (SD) age at surgery was 17.1 (1.56) years and the median BMI was 50.4. Participants were predominantly female (77%), white (73%), and non-Hispanic (93%). Among the participants, 49% had poor functional status and 76% had musculoskeletal pain. Lower back pain was prevalent (63%), followed by ankle/foot (53%), knee (49%), and hip (31%) pain; 26% had pain at all 4 sites. In adjusted analyses, compared with pain-free participants, those reporting lower extremity pain had greater odds of having poor physical function according to scores on the Health Assessment Questionnaire Disability Index (odds ratio = 2.82; 95% CI, 1.35 to 5.88; P < .01). Compared with pain-free participants, those reporting lower extremity pain had significantly lower Impact of Weight on Quality of Life-Kids total scores (β = -9.42; 95% CI, -14.15 to -4.69; P < .01) and physical comfort scores (β = -17.29; 95% CI, -23.32 to -11.25; P < .01). After adjustment, no significant relationship was observed between musculoskeletal pain and high-sensitivity C-reactive protein level.

CONCLUSIONS AND RELEVANCE

Adolescents with severe obesity have musculoskeletal pain that limits their physical function and quality of life. Longitudinal follow-up will reveal whether weight loss surgery reverses pain and physical functional limitations and improves quality of life.

Chronic pain, body mass index and cardiovascular disease risk factors: tests of moderation, unique and shared relationships in the Study of Women's Health Across the Nation (SWAN)

Chronic pain may be related to cardiovascular disease (CVD) risk. The current study examined whether persistent bodily pain was related to cardiovascular disease risk factors, whether these effects were moderated by body mass index (BMI), and, if not, whether chronic pain accounted for unique variance in CVD risk factors. Participants were women (N = 2,135) in the Study of Women's Health Across the Nation. A high pain frequency variable (high pain in 0 through 4 assessments) was coded to reflect the frequency of high levels of bodily pain across the first 3 years of the study. Six CVD risk factors and BMI were measured at follow-up year 3. High pain frequency and BMI were correlated significantly with risk factors, although effects for the former were small. Hierarchical multiple regressions revealed high pain frequency × BMI interactions for 5 of 6 CVD risk factors. Dissecting the interactions revealed a similar pattern across 4 risk factors: for women with normal BMI, there was a "dose-response" in which increasing frequency of high pain revealed increasingly worse CVD risk factor levels, whereas for women with obese BMI, high pain frequency was unrelated to risk factors. For obese women, increasing frequency of high pain was associated with higher blood glucose. Although BMI is a well-established CVD risk factor, evaluation of CVD risk level may be improved by considering the incidence of persistent pain, particularly in normal weight women (BMI < 25 kg/m(2)) lower BMI.

Blood testing in chronic pain management

Blood testing is quickly becoming a useful laboratory tool for opioid prescribers who wish to document and assess patient tolerance, more objectively monitor patient safety, and evaluate patient compliance using information that is not available with traditional urine drug testing (UDT). Blood testing does not need to be performed as frequently as UDT but provides extremely valuable information which can be used to more accurately evaluate patient compliance and assist with interpreting blood toxicology results commonly used in impairment or overdose cases. This narrative review presents the current evidence supporting the use of blood testing within the chronic pain management setting. In addition, this review aims to introduce and discuss the role of routine blood testing within the chronic pain management setting. Blood testing for the purpose of documenting opioid tolerance is a relatively novel tool for pain physicians and as such this review is not intended to be a comprehensive or exhaustive review of the scientific or medical literature. Prescribers must also be aware that this type of laboratory testing need only be administered to chronic pain patients receiving daily opioid therapy. Patients taking infrequent, low dose, or as needed medications are not anticipated to benefit from this type of test. Based on the complexity of both achieving acceptable outcomes with opioid treatment and the legal and societal issues at hand, we feel that the addition of blood concentration levels will become the standard of care in the near future.

Circulating microRNA expression profile: a novel potential predictor for chronic nervous lesions

The mechanisms of chronic neuropathic pain are not clear. Serum microRNAs (miRNAs) might show a special feature for chronic nervous lesions. However, little is known about the changes in circulating miRNAs for the neuropathic pain. Therefore, changes in the circulating miRNAs expression profile for the neuropathic pain were investigated. Serum was collected from rats before and after spinal nerve ligation (SNL) surgery, and a microarray analysis was performed to determine the changes in miRNA expression profile. The expression of inflammatory cytokines in serum from the same individuals, including interleukin-6 (IL-6), tumor necrosis factor-α (TNF-α), and monocyte chemotactic protein-1 (MCP-1), was also measured. The results showed that the expression levels of IL-6, TNF-α, and MCP-1 were significantly elevated in SNL rats which were significantly correlated with pain levels. Nine miRNAs with significantly different expression levels before and after SNL surgery were identified by microarray analysis, which were further validated by quantitative real-time polymerase chain reaction analyses. Compared with naive rats without SNL surgery, the expression of five miRNAs (hsa-miR-221, hsa-miR-34c, hsa-miR-21, hsa-miR-30a-5p, and hsa-miR-206) in the serum of rats after SNL surgery was decreased and four miRNAs (hsa-miR-31-5p, hsa-miR-133b, hsa-miR-22, and hsa-miRPlus-A1087) were increased, suggesting that miRNA changes may involve in the regulation of neuropathic pain. TargetScan was used to predict mRNA targets for these miRNAs, and the results showed that the transcripts with multiple predicted target sites belonged to neurologically important pathways. Bioinformatics analysis revealed that several target genes are related to the activation of cell signaling associated with nervous lesions. In this study, the changes to miRNA profiles in serum under neuropathic pain conditions were shown for the first time, suggesting that circulating miRNAs profile in serum is a potential predictor for neuropathic pain.

Dietary omega-6 fatty acid lowering increases bioavailability of omega-3 polyunsaturated fatty acids in human plasma lipid pools

BACKGROUND

Dietary linoleic acid (LA, 18:2n-6) lowering in rats reduces n-6 polyunsaturated fatty acid (PUFA) plasma concentrations and increases n-3 PUFA (eicosapentaenoic (EPA) and docosahexaenoic acid (DHA)) concentrations.

OBJECTIVE

To evaluate the extent to which 12 weeks of dietary n-6 PUFA lowering, with or without increased dietary n-3 PUFAs, alters unesterified and esterified plasma n-6 and n-3 PUFA concentrations in subjects with chronic headache.

DESIGN

Secondary analysis of a randomized trial. Subjects with chronic headache were randomized for 12 weeks to (1) average n-3, low n-6 (L6) diet; or (2) high n-3, low n-6 LA (H3-L6) diet. Esterified and unesterified plasma fatty acids were quantified at baseline (0 weeks) and after 12 weeks on a diet.

RESULTS

Compared to baseline, the L6 diet reduced esterified plasma LA and increased esterified n-3 PUFA concentrations (nmol/ml), but did not significantly change plasma arachidonic acid (AA, 20:4n-6) concentration. In addition, unesterified EPA concentration was increased significantly among unesterified fatty acids. The H3-L6 diet decreased esterified LA and AA concentrations, and produced more marked increases in esterified and unesterified n-3 PUFA concentrations.

CONCLUSION

Dietary n-6 PUFA lowering for 12 weeks significantly reduces LA and increases n-3 PUFA concentrations in plasma, without altering plasma AA concentration. A concurrent increase in dietary n-3 PUFAs for 12 weeks further increases n-3 PUFA plasma concentrations and reduces AA.

Clearance of meperidine and its metabolite normeperidine in hemodialysis patients with chronic noncancer pain

CONTEXT

Normeperidine accumulates in patients with impaired renal function and may cause central neurotoxicity. However, some uremic patients still undergo meperidine treatment for chronic pain.

OBJECTIVES

To prevent normeperidine side effects and complications, we investigated the clearance rate and extraction ratio of meperidine and normeperidine in hemodialysis patients with chronic pain.

METHODS

Three hemodialysis patients, with diagnoses of chronic pancreatitis, chronic back pain, and intractable intra-abdominal pain, received long-term (more than six months) administration of meperidine for chronic noncancer pain. During regular hemodialysis, 72 blood samples in total were collected from the afferent port, efferent port, and ultradiafiltrate port at eight time points. The plasma concentrations of meperidine and normeperidine were determined by high-performance liquid chromatography.

RESULTS

The prehemodialysis plasma concentrations of meperidine and normeperidine were 2963 ± 315 and 2369 ± 1974 ng/mL, which declined to 591 ± 109 and 853 ± 765 ng/mL, with 80% and 65% reduction, respectively. The plasma clearance and extraction ratios of meperidine were 22.7 ± 9.8 mL/minute and 10.1 ± 5.6% and for normeperidine 26.0 ± 11.4 mL/minute and 10.8 ± 2.5%, respectively.

CONCLUSION

Hemodialysis can efficiently remove meperidine and its active metabolite, normeperidine, in uremic patients receiving long-term meperidine therapy for chronic noncancer pain.

[Chronic non-cancer-related pain. Long-term treatment with rapid-release and short-acting opioids in the context of misuse and dependency]

Annually published data show a continual increase in the volume of opioid prescriptions in Germany, thus indicating an intensification of opioid therapy. The majority of opioids are prescribed to treat chronic non-cancer-related pain. On the basis of current guidelines, as well as in terms of the lack of data regarding long-term use of opioids and their effectiveness beyond a period of 3 months, this development must be viewed critically. With reference to four case reports, we discuss and evaluate opioid therapy in relation to medication misuse and the development of drug dependency. Particular emphasis is placed on the administration of rapid-release and short-acting opioid preparations, which we consider to be particularly problematic.

Medication compliance in patients with chronic pain

BACKGROUND

Despite hints about the high incidence of pain patients misreporting their pain medication use, there are only a few non-controlled studies on the topic that focus solely on opioids.

OBJECTIVE

Using toxicological analyses in a cross-sectional study, we investigated patients' reliability regarding their report of any current pain medication use.

STUDY DESIGN

A cross-sectional study.

SETTING

A comprehensive pain center and a surgical unit of a German University Hospital.

METHODS

Consecutive outpatients at their first visit to the pain clinic (PG, n = 243) and pre-surgical control patients (SG, n = 100) suffering from pain reported on their current pain medication. The patients' reports were verified in serum and urine using specific toxicological methods. Two types of noncompliance were defined: under-reporting (detection of non-reported substances) and over-reporting (reported substances undetectable). The impact of clinical parameters on compliance was investigated using binary logistic regression.

RESULTS

The incidence of noncompliance was significantly higher in the PG (43.3%) than in the SG (24%; P < 0.05). Under-reporting occurred similarly in both groups (31% PG; 23% SG), whereas over-reporting predominantly appeared in the PG (11% vs. 2%; P < 0.05). Opioids were not most frequently under-reported, but the highest proportion of under-reported drugs (under-reported in relation to detection incidence) was found for non-opioid analgesics (NSAIDs: 29% PG; 25% SG; other: 42% PG; 32% SG) and psychotropic drugs (35% PG; 53% SG). In the PG, logistic regression revealed high depression scores to be predictive for noncompliance (odds ratio 2.12).

LIMITATIONS

Due to lack of a structured follow-up interview motives of under- and over-reporting stay speculative.

CONCLUSIONS

Under-reporting of non-opioid analgesics is the main type of noncompliance, a disquieting fact in light of their toxicity and adverse effects. Further research is required in terms of drug assessment and compliance improvement strategies in pain clinics; therefore, toxicological monitoring is indispensable.

CLINICAL TRIAL

NCT01625065; Medi-3889-10.

Crocin improved locomotor function and mechanical behavior in the rat model of contused spinal cord injury through decreasing calcitonin gene related peptide (CGRP)

Various approaches have been offered to alleviate chronic pain resulting from spinal cord injuries (SCIs). Application of herbs and natural products, with potentially lower adverse effects, to cure diseases has been recommended in both traditional and modern medicines. Here, the effect of crocin on chronic pain induced by spinal cord contusion was investigated in an animal model. Female Wistar rats were randomly divided into five groups (5 rats in each); three groups were contused at the L1 level. One group was treated with crocin (150mg/kg) two weeks after spinal cord injury; the second group, control, was treated with vehicle only; and the third group was treated with ketoprofen. Two normal groups were also considered with or without crocin treatment. The mechanical behavioral test, the locomotor recovery test and the thermal behavioral test were applied weekly to evaluate the injury and recovery of rats. Significant improvements (p<0.05) in mechanical behavioral and locomotor recovery tests were seen in the rats treated with crocin. Thermal behavioral test did not show any significant changes due to crocin treatment. Plasma concentration of calcitonin-gene related peptide (CGRP) changed from 780.2±2.3 to 1140.3±4.5pg/ml due to SCI and reached 789.1±2.7pg/ml after crocin treatment. These changes were significant at the level of p<0.05. The present study shows the beneficial effects of crocin treatment on chronic pain induced by SCI, through decreasing CGRP as an important mediator of inflammation and pain.

Association of pain with HbA1c in a predominantly black population of community-dwelling adults with diabetes: a cross-sectional analysis

AIMS

To assess the relationship between pain and HbA(1c) levels in a predominantly black population with diabetes, and to determine whether self-management behaviours (exercise and diet) and symptoms of depression mediate this relationship.

METHODS

We analysed cross-sectional data from 417 community-dwelling individuals with diabetes in rural Alabama, USA. Binary logistic regression was used to analyse the relationship between pain and HbA(1c) levels, defined as relatively good [≤ 64 mmol/mol (≤ 8.0%)] and relatively poor [> 64 mmol/mol (> 8.0%)], after adjusting for sociodemographics, insulin use, medication count, cigarette smoking history and body mass index (BMI). We examined the mediating roles of exercise, diet, and symptoms of depression using bootstrapping.

RESULTS

Participants were primarily black (86.6%), female (76.1%) and reported an annual income of ≤$20,000 (52.7%). Their mean (sd) age was 59.6 (12.8) years. The majority of the participants reported moderate to extreme pain (71.5%). Participants reporting pain were more than twice as likely to have HbA(1c) levels > 64 mmol/mol (8.0%) in the fully adjusted model (odds ratio 2.33 [95% CI 1.28-4.24]; P < 0.05). Diet significantly mediated the relationship between pain and HbA(1c) control (β = 0.06; 95% CI: 0.01-0.17), but only in the unadjusted model. Exercise and symptoms of depression were not significant mediators.

CONCLUSIONS

A significant independent relationship between pain and HbA(1c) control was found in this mainly black population, which was not explained by self-management behaviours or symptoms of depression. Future research is needed to delineate the mechanism by which pain influences HbA(1c) control, especially among black people with diabetes on low incomes.

Psychologic and biologic factors associated with fatigue in patients with persistent radiculopathy

Fatigue is a common symptom associated with neuropathic pain (NP) and can have negative consequences on psychosocial functioning, physical endurance, and quality of life. Recent evidence indicates that immune activation modulated through the increased release of proinflammatory cytokines can predict fatigue in some patient populations. Although earlier studies have shown that immune activation is a pathophysiologic feature of NP, there have been no studies to examine the relationship between immune activation and fatigue in persons with NP. Therefore, the purpose of this exploratory study was to: 1) determine the relationships among fatigue, pain, psychosocial factors, and selected biologic markers of immune activation (interleukin [IL] 6 and soluble IL-6 receptor [sIL-6R]) in participants with persistent radiculopathy; and 2) determine the differences in these variables based on fatigue severity. Participants (n = 80) were classified according to their level of fatigue as low (27.5%), moderate (32.5%), or high (40%), and significant differences were found between fatigue categories (p = .001). Multivariate analyses of variance revealed that individuals with moderate to high levels of fatigue differed from those with the lowest levels of fatigue in psychologic distress, depressive symptoms, IL-6, and sIL-6R, whereas the differences between moderate and high levels of fatigue were significant for psychologic distress and sIL-6R only. The findings suggest that immune activation affects fatigue severity and possibly other behavioral responses, offering important information when providing care to patients with persistent radiculopathy. The integration of biobehavioral nursing interventions in pain management may have a greater impact on quality of life than treatment focused only on pain.

[Antibodies to endogenous bioregulators and their association with age and sex in chronic pain syndrome]

Authors studied changes in the levels of antibodies to endogenous bioregulators (Ab) to Β-endorphin, orphanin, serotonin, dopamine and angiotensin in 36 healthy people and 109 patients with dorsopathy with chronic pain syndrome. The association of these immunological indicators with age and sex was found. It has been concluded that the levels of Ab to endogenous bioregulators may be considered as a marker of algic system pathology that does not depend on age and is sex-related.

The effect of social stress on chronic pain perception in female and male mice

The current investigations on social stress primarily point to the negative health consequences of being in a stressful social hierarchy. The repetitive nature of such stressors seems to affect behavioral response to pain both in rodents and humans. Moreover, a large discrepancy in the possibility of social stresses affecting pain perception in the two genders exists. The present study examined the effect of chronic social stress on nociceptive responses of both sexes by implementing of food deprivation, food intake inequality and unstable social status (cage-mate change every 3 days) for a period of 14 days in 96 Balb/c mice. In this regard we injected 20 µl formalin 2% into the plantar surface of hind paw at the end of stress period and scored pain behaviors of all subjects, then serum concentrations of proinflammatory cytokines were measured. Our results showed that there was significant difference in chronic phase of formalin test following implementation of food deprivation and inequality (P<0.05) as compared to control group, so that pain perception was decreased considerably and this decline in inequality exposed subjects was well above isolated ones (P<0.05); whereas unstable social situation did not affect pain perception. Moreover, IL-1 and IL-6 concentrations in serum of stressed mice of both genders were well above control group (p<0.05). Finally, despite chronic pain perception in control and unstable male subjects was larger than females; the decrease of chronic pain perception in male stressed animals (poverty and inequality experienced subjects) was much more than stressed females. These results revealed that although food deprivation and social inequality can induce hypoalgesia, some socioeconomic situations like social instability don't affect pain sensation, whereas there were similar increases of proinflammatory cytokines level in all socially stressed subjects. In addition, males display larger hypoalgesic responses to inequality as compared with females.

[Whether dyslipidemia plays the pathogenetic role in the development of noninflammatory chronic prostatitis/chronic pelvic pain syndrome?]

The study examined symptomatology in 74 patients with chronic abacterial prostatitis. The features of blood lipid metabolism in inflammatory and noninflammatory forms of disease are redefined. Dynamic characteristics of arterial blood flow in the prostate gland of patients with chronic abacterial prostatitis are determined. Comparative analysis between groups revealed significant differences in some indices of blood lipid profile, and arterial flow velocity parameters of the prostate in patients studied; correlations between the intensity of pain, the type of dyslipoproteinemia and arterial ischemia of the prostate are shown. The feasibility of analysis of the blood lipoprotein spectrum in the differential diagnosis of inflammatory and noninflammatory forms of chronic abacterial prostatitis is demonstrated.

Misdiagnosis in fibromyalgia: a multicentre study

BACKGROUND

Fibromyalgia (FM) is the second most common cause of visits to rheumatologists after osteoarthritis, and may be difficult to diagnose in many patients. It is associated with various rheumatic disorders such as rheumatoid arthritis, spondyloarthropathies (SpA) and connective tissue disease (CTD), and a late diagnosis or misdiagnosis is a common and underestimated problem.

OBJECTIVES

The aim of this study was to investigate the 'underdiagnosis' of FM, and which rheumatic diseases tend to be confused with it.

METHODS

The following data were collected at baseline: symptoms, disease duration, physical examination findings, previous and current investigations and management, laboratory tests, tender point count, tender and swollen joint counts, and spinal pain. The clinimetric evaluation included the Fibromyalgia Impact Questionnaire (FIQ) and Fibromyalgia Assessment Status (FAS).

RESULTS

The study population consisted of 427 outpatients (418 females and 9 males; mean age 49.3 years; mean disease duration 8.5 years). Fifty-seven patients (13.3%) had been previously misdiagnosed as having other musculoskeletal disorders (MSDs); 370 patients had been previous correctly diagnosed as having FM, or were diagnosed as having it during the course of the study. The FM and MSD groups were comparable in terms of demographic data and referral patterns. Disease duration was longer and the erythrocyte sedimentation rate was higher in the MSD patients, who also had less severe FIQ and lower pain visual analogue scale scores. Moreover, the FIQ and FAS scores correlated in the MS group.

CONCLUSIONS

The findings of this study suggest that, although FM is a wellknown clinical entity, differential diagnosis with SpA, CTD and inflammatory arthritis can still be a challenge for rheumatologists and general practitioners.