The prevalence and years lived with disability caused by low back pain in China, 1990 to 2016: findings from the global burden of disease study 2016

The Physical and Psychological Effects of Telerehabilitation-Based Exercise for Patients With Nonspecific Low Back Pain: Prospective Randomized Controlled Trial

Background

Physical therapy has demonstrated efficacy in managing nonspecific low back pain (NLBP) among patients. Nevertheless, the prevalence of NLBP poses a challenge, as the existing medical infrastructure may be insufficient to care for the large patient population, particularly in geographically remote regions. Telerehabilitation emerges as a promising method to address this concern by offering a method to deliver superior medical care to a greater number of patients with NLBP.

Objective

The purpose of this study is to demonstrate the physical and psychological effectiveness of a user-centered telerehabilitation program, consisting of a smartphone app and integrated sensors, for patients with NLBP.

Methods

This was a single-center, prospective, randomized controlled trial for individuals with NLBP for a duration exceeding 3 months. All participants were assigned randomly to either the telerehabilitation-based exercise group (TBEG) or the outpatient-based exercise group (OBEG). All participants completed a 30-minute regimen of strength and stretching exercises 3 times per week, for a total of 8 weeks, and were required to complete assessment questionnaires at 0, 2, 4, and 8 weeks. The TBEG completed home-based exercises and questionnaires using a telerehabilitation program, while the OBEG completed them in outpatient rehabilitation. The Oswestry Disability Index (ODI) served as the primary outcome measure, assessing physical disability. Secondary outcomes included the Numeric Pain Rating Scale, Fear-Avoidance Beliefs Questionnaire, and 36-item Short-Form Health Survey.

Results

In total, 54 of 129 eligible patients were enrolled and randomly assigned to the study. The completion of all the interventions and assessments in the TBEG and OBEG was 89% (24/27) and 81% (22/27). The findings indicate that no statistical significance was found in the difference of ODI scores between the TBEG and the OBEG at 2 weeks (mean difference -0.91; odds ratio [OR] 0.78, 95% CI -5.96 to 4.14; P=.72), 4 weeks (mean difference -3.80; OR 1.33, 95% CI -9.86 to -2.25; P=.21), and 8 weeks (mean difference -3.24; OR 0.92, 95% CI -8.65 to 2.17; P=.24). The improvement of the ODI in the TBEG (mean -16.42, SD 7.30) and OBEG (mean -13.18, SD 8.48) was higher than 10 after an 8-week intervention. No statistically significant differences were observed between the 2 groups at the 8-week mark regarding the Fear-Avoidance Beliefs Questionnaire (mean difference 8.88; OR 1.04, 95% CI -2.29 to 20.06; P=.12) and Numeric Pain Rating Scale (mean difference -0.39; OR 0.44, 95% CI -2.10 to 1.31; P=.64). In the subgroup analysis, there was no statistically significant difference in outcomes between the 2 groups.

Conclusions

Telerehabilitation interventions demonstrate comparable therapeutic efficacy for individuals with NLBP when compared to conventional outpatient-based physical therapy, yielding comparable outcomes in pain reduction and improvement in functional limitations.

Cortical Mechanisms Underlying Effects of Repetitive Peripheral Magnetic Stimulation on Dynamic and Static Postural Control in Patients with Chronic Non-Specific Low Back Pain: A Double-Blind Randomized Clinical Trial

INTRODUCTION

Patients with chronic non-specific low back pain (CNLBP) often experience impaired postural control, contributing to pain recurrence. Although repetitive peripheral magnetic stimulation (rPMS) combined with core muscle training (CMT) could improve postural control, its neural mechanism remains unclear. This study aims to investigate the postural control-related cortical mechanism of the effect of rPMS on patients with CNLBP.

METHODS

This unicentric, prospective, randomized, double-blind, controlled trial was conducted in a public hospital from May to December 2023. A total of 40 patients (27 females and 13 males, mean age 29.38 ± 7.72) with CNLBP were randomly assigned to either the rPMS group (real rPMS with CMT) or the sham-rPMS group (sham-rPMS with CMT) for 12 sessions over 4 weeks. The rPMS was applied to the lumbar paravertebral multifidus muscle on the painful side. Pain and disability were quantified using the visual analog scale (VAS) and Oswestry dysfunction index (ODI) pre- and post-intervention. Furthermore, the sway area and velocity of the center of pressure (COP) were measured using a force platform. The cortical activities in 6 regions of interest during 4 tasks (standing with eyes open/closed on a stable/unstable plane) were recorded by functional near-infrared spectroscopy (fNIRS) pre- and post-intervention. The repeated measure ANOVA was applied for statistical analysis. Spearman's correlation was used to determine the relationships between variables.

RESULTS

After the intervention, the rPMS group showed decreased pain intensity (p = 0.001) and sway area (unstable eyes-closed task) (p = 0.046) compared to the sham-rPMS group. Additionally, the rPMS group exhibited increased activation in left primary motor cortex (M1) (p = 0.042) and reduced in left supplementary motor area (SMA) (p = 0.045), whereas the sham-rPMS group showed no significant changes. The increased activation of left M1 was negatively correlated to the reduction of pain intensity (r = - 0.537, p = 0.018) and sway area (r = - 0.500, p = 0.029) under the static balancing task. Furthermore, there was a positive correlation between sway velocity and VAS (r = 0.451, p = 0.046) post-rPMS intervention.

CONCLUSION

Repetitive peripheral magnetic stimulation combined with core muscle training demonstrated better analgesic effects and postural control improvements, compared to sham-stimulation. This may be attributed to the increased activation of the left primary motor cortex.

CLINICAL TRIAL REGISTRATION

The trial was registered on ClinicalTrials.gov (ChiCTR2300070943).

Comparative Review of the Socioeconomic Burden of Lower Back Pain in the United States and Globally

Internationally, the United States (U.S.) cites the highest cost burden of low back pain (LBP). The cost continues to rise, faster than the rate of inflation and overall growth of health expenditures. We performed a comprehensive literature review of peer-reviewed and non- peer-reviewed literature from PubMed, Scopus, and Google Scholar for contemporary data on prevalence, cost, and projected future costs. Policymakers in the U.S. have long attempted to address the high-cost burden of LBP through limiting low-value services and early imaging. Despite these efforts, costs (~$40 billion; ~$2,000/patient/yr) continue to rise with increasing rates of unindicated imaging, high rates of surgery, and subsequent revision surgery without proper trial of non-pharmacologic measures and no corresponding reduction in LBP prevalence. Globally, the overall prevalence of LBP continues to rise largely secondary to a growing aging population. Cost containment methods should focus on careful and comprehensive clinical assessment of patients to better understand when more resource-intensive interventions are indicated.

Association of depressive symptoms with risk of incidence low back pain in middle-aged and older Chinese adults

BACKGROUND

Elevated Depressive symptoms (DS) and low back pain (LBP) pose significant and growing public health challenges, and China is no exception. This study innovatively examined the relationship between specific DS and distinct patterns of DS and incident LBP.

METHODS

This study extracted data from 4713 participants aged 45+ years from the China and Health Retirement Longitudinal Study (CHARLS), followed-up for incidence LBP (June 2011-September 2020). DS was assessed by the 10-item Center for Epidemiological Studies Depression Scale (CESD-10). The incident LBP was determined by self-reported. Latent class analysis (LCA) was employed to categorize patterns of DS. Cox proportional hazards regression models were used to examine the association between DS and incident LBP.

RESULTS

Over the 9.25-year follow-up period, 2234 incident LBP cases were identified. There was a significant independent association between positive DS and incident LBP with an HR of 1.73 (95 % CI = 1.55-1.94). Of the 10-item DS, difficulty concentrating (adjusted HR = 1.16, 95 % CI = 1.03-1.31), effortfulness (adjusted HR = 1.32, 95 % CI = 1.18-1.49), hopelessness (adjusted HR = 1.13, 95 % CI = 1.02-1.25), restless sleep (adjusted HR = 1.17, 95 % CI = 1.06-1.30), and loneliness (adjusted HR = 1.18, 95 % CI = 1.02-1.36), each independently associated with incident LBP. Regarding patterns of DS, compared to the "healthy" pattern of DS, four patterns showed significant association with incident LBP, especially the cumulative pattern of DS.

LIMITATIONS

DS and LBP were assessed based on self-reported.

CONCLUSIONS

In middle-aged and older Chinese adults, 5 specific DS (difficulty concentrating, effortfulness, hopelessness, restless sleep, and loneliness) and distinct patterns of DS indicate varied risks of developing LBP.

Burden of neck pain in general population of China, 1990-2019: An analysis for the Global Burden of Disease Study 2019

Background

Neck pain has become very common in China and has greatly affected individuals, families, and society in general. In this study, we aimed to report on the rates and trends of the prevalence, incidence, and years lived with disability (YLDs) caused by neck pain in the general population of China from 1990 to 2019.

Methods

We used data from the Global Burden of Diseases, Injuries, and Risk Factors Study 2019 (GBD 2019) study to estimate the number and age standardised rates per 100 000 population of neck pain point prevalence, annual incidence, and YLDs in 33 provinces/municipalities/autonomous regions of China, stratified by age, sex, and sociodemographic index (SDI) from 1990 to 2019. We then compared these estimates with other G20 countries.

Results

There were 6.80 × 107 patients with neck pain in 2019, presenting an increase from 3.79 × 107 in 1990. Likewise, the national age-standardised point prevalence increased slightly from 3.53% in 1990 to 3.57% in 2019. The YLDs increased by 78.08%, from 3814 × 103 in 1990 to 6792 × 103 in 2019. The age-standardised YLDs rate increased 1.50% from 352.84 in 1990 to 358.10 in 2019. The point prevalence of neck pain in 2019 was higher in females compared with males. These estimates were all above the global average level and increased more rapidly among G20 countries from 1990 to 2019. We generally observed a positive association between age-standardised YLD rates for neck pain and SDI, suggesting the burden is higher at higher sociodemographic indices.

Conclusions

Neck pain is a serious public health problem in the general population in China, especially in its central and western regions, with an overall increasing trend in the last three decades. This is possibly related to changes of people's lifestyles and work patterns due to improvements in societal well-being and technology. Raising awareness of risk factors for neck pain in the general population and establishing effective preventive and treatment strategies could help reduce the future burden of neck disorders.

The epidemiology of neck and low back pain in Iran: a national and sub-national analysis from 1990 to 2019

Background

Neck pain (NP) is a condition influenced by multiple factors. It places a significant burden on individuals suffering from NP and on social and economic systems. On a global scale, low back pain (LBP) stands out as a significant contributor to years lost to disability, and this burden is on the rise due to population growth and aging.

Methods

The Global Burden of Disease database was used to collect data on the prevalence, incidence, and years lived with disability (YLD) of NP and LBP between 1990 and 2019. Various factors, including age group, gender, Iran, and its 31 provinces, were used to classify the data.

Results

Iran accounted for 0.86 million incident cases of NP in 2019, with age-standardized incident rate per 100 000 population of 934.1. Tehran has the maximum age-standardized prevalence, incidence, and YLD. Iran accounted for the age-standardized incidence rate for LBP per 100 000 population of 3492.9, and it reduced to -8.35% from 1990. Mazandaran exhibits the highest levels of prevalence, incidence, and YLD for LBP in 2019. In Iran, the point prevalence of NP in 2019 was higher in females and increased with age up to 50-54 years for females and 70-74 years for males. However, there is only a slight difference between females and males in Iran regarding LBP prevalence.

Conclusions

In this study, the authors report the prevalence, incidence, YLD, and age-standardized rates for NP and LBP in the world's general population and Iran's population based on its sub-nations in 1990 and 2019.

Mitochondrial-Targeted Metal-Phenolic Nanoparticles to Attenuate Intervertebral Disc Degeneration: Alleviating Oxidative Stress and Mitochondrial Dysfunction

As intervertebral disc degeneration (IVDD) proceeds, the dysfunctional mitochondria disrupt the viability of nucleus pulposus cells, initiating the degradation of the extracellular matrix. To date, there is a lack of effective therapies targeting the mitochondria of nucleus pulposus cells. Here, we synthesized polygallic acid-manganese (PGA-Mn) nanoparticles via self-assembly polymerization of gallic acid in an aqueous medium and introduced a mitochondrial targeting peptide (TP04) onto the nanoparticles using a Schiff base linkage, resulting in PGA-Mn-TP04 nanoparticles. With a size smaller than 50 nm, PGA-Mn-TP04 possesses pH-buffering capacity, avoiding lysosomal confinement and selectively accumulating within mitochondria through electrostatic interactions. The rapid electron exchange between manganese ions and gallic acid enhances the redox capability of PGA-Mn-TP04, effectively reducing mitochondrial damage caused by mitochondrial reactive oxygen species. Moreover, PGA-Mn-TP04 restores mitochondrial function by facilitating the fusion of mitochondria and minimizing their fission, thereby sustaining the vitality of nucleus pulposus cells. In the rat IVDD model, PGA-Mn-TP04 maintained intervertebral disc height and nucleus pulposus tissue hydration. It offers a nonoperative treatment approach for IVDD and other skeletal muscle diseases resulting from mitochondrial dysfunction, presenting an alternative to traditional surgical interventions.

Evaluation of three decades of the burden of low back pain in China before COVID-19: Estimates from the Global Burden of Disease Database 2019

Background

Low back pain (LBP) is reported as an urgent public-health concern globally because it occurs in all age groups and is now the leading cause of disability, with health systems unable to cope with this burden. We present China's burden of LBP by estimating its prevalence and years lived with disability (YLDs) from 1990 to 2019.

Methods

We obtained the data relating to LBP from the Global Burden of Disease Database (GBD) 2019. Then we calculated years lived with disability caused by LBP by multiplying the prevalence of LBP sequelae by their corresponding disability weights. We performed an analysis of the age-, sex-, and province-specific prevalence and YLDs of 33 provinces/regions in China, as well as their relationship with the sociodemographic index (SDI).

Results

China has the largest numbers of people with LBP (91.3 million) and YLDs (8.6 million) globally, and LBP is the leading cause of YLDs. The age-standardised prevalence was 7.25% in 1990, and this decreased to 5.13% in 2019. The age-standardised YLD rate was 579/100 000 in 2019, having decreased by 28.97%. Both measurements increased with age, being higher in women and varying across the 33 provinces/regions. For the 5-to-14-year age group, the prevalence (4.50%) and YLD rate (4.51%) increased in 2019 from 1990 (3.21% and 3.21%, respectively) when compared to the elderly group. Age-standardised YLD rates experienced decreases with increasing SDI, while there was an increasing tendency as SDI increased further; the changes for women were more obvious.

Conclusions

Over the three decades considered, China has continued to have the largest number of people with LBP in the world, even though the age-standardised prevalence has decreased. YLDs were found to decrease as SDI increased, but they subsequently increased again. LBP still presents a burden, particularly for children and postmenopausal women.

Research on the multidimensional brain remodeling mechanisms at the level of brain regions, circuits, and networks in patients with chronic lower back pain caused by lumbar disk herniation

Introduction

Chronic lower back pain (cLBP), frequently attributed to lumbar disk herniation (LDH), imposes substantial limitations on daily activities. Despite its prevalence, the neural mechanisms underlying lower back pain remain incompletely elucidated. Functional magnetic resonance imaging (fMRI) emerges as a non-invasive modality extensively employed for investigating neuroplastic changes in neuroscience. In this study, task-based and resting-state fMRI methodologies are employed to probe the central mechanisms of lower back pain.

Methods

The study included 71 chronic lower back pain patients (cLBP group) due to LDH and 80 age, gender, and education-matched healthy volunteers (HC group). The subjects are mainly middle-aged and elderly individuals. Visual Analog Scale (VAS), Oswestry Disability Index (ODI), and Japanese Orthopedic Association Scores (JOA) were recorded. Resting-state and task-based fMRI data were collected.

Results/discussion

No significant differences were observed in age, gender, and education level between the two groups. In the cLBP group during task execution, there was diffuse and reduced activation observed in the primary motor cortex and supplementary motor area. Additionally, during resting states, notable changes were detected in brain regions, particularly in the frontal lobe, primary sensory area, primary motor cortex, precuneus, and caudate nucleus, accompanied by alterations in Amplitude of Low Frequency Fluctuation, Regional Homogeneity, Degree Centrality, and functional connectivity. These findings suggest that chronic lower back pain may entail reduced excitability in sensory-motor areas during tasks and heightened activity in the sensory-motor network during resting states, along with modified functional connectivity in various brain regions.

Global, Regional, and National Change Patterns in the Incidence of Low Back Pain From 1990 to 2019 and Its Predicted Level in the Next Decade

Objectives: To analyze and describe the spatiotemporal trends of Low back pain (LBP) burdens from 1990 to 2019 and anticipate the following decade's incidence. Methods: Using data from the Global Burden of Disease (GBD) 2019 Study, we described net drifts, local drifts, age effects, and period cohort effects in incidence and forecasted incidence rates and cases by sex from 2020 to 2029 using the Nordpred R package. Results: LBP remained the leading cause of the musculoskeletal disease burden globally and across all socio-demographic index (SDI) regions. China is the top country. For recent periods, high-SDI countries faced unfavorable or worsening risks. The relative risk of incidence showed improving trends over time and in successively younger birth cohorts amongst low-middle-, middle- and high-middle-SDI countries. Additionally, the age-standardized incidence rates (ASIR) of LBP in both sexes globally showed a decreasing trend, but the incident cases would increase from 223 to 253 million overall in the next decade. Conclusion: As the population ages, incident cases will rise but ASIR will fall. To minimise LBP, public awareness and disease prevention and control are needed.

Estimating surgical probability: Development and validation of a prognostic model for patients with lumbar disc herniation treated with acupuncture

Lumbar disc herniation (LDH) is a common cause of pain in the lumbar spine and legs. While acupuncture has become the primary conservative treatment for LDH, some patients experience treatment failure and require surgery, causing substantial concern for clinicians. We developed an effective personalized clinical prediction model to identify the independent risk factors associated with acupuncture failure in patients with LDH. Our model aimed to predict the probability of surgery within 6 months of acupuncture failure in patients with LDH. A total of 738 patients with LDH who underwent acupuncture at 4 Chinese hospitals between January 2019 and October 2021 were selected. The patients were divided into training (n = 496) and validation (n = 242) cohorts. Seven predictive variables, including smoking, Oswestry Disability Index (ODI) score, lower-limb herniation, disc herniation type, lumbar spinal stenosis, lumbar lateral recess stenosis, and acupuncture frequency, were selected as risk factors using least absolute shrinkage and selection operato (LASSO) regression. A prediction model was developed using multivariate logistic regression analysis and a nomogram was constructed. The model exhibited good discrimination, with an area under the ROC curve (AUC) of 0.903 for the development cohort and 0.899 for the validation cohort. The Hosmer-Lemeshow goodness-of-fit test was a good fit for both cohorts (P = .956 for the development cohort; P = .513 for the validation cohort). Decision curve analysis (DCA) demonstrated that the threshold probabilities for the 2 cohorts ranged from > 4% and 5-95%, respectively. Therefore, the prediction model had a good net benefit. The nomogram established in this study, incorporating 7 risk factors, demonstrated a good predictive ability. It could predict acupuncture failure in LDH patients and the risk of surgery within 6 months, enabling physicians to conduct individualized treatment measures.

Postoperative Evaluation of Pain and Disability in Patients Undergoing Spinal Discectomy

BACKGROUND

A spinal discectomy surgery (SDS) is a common surgical procedure performed to treat lumbosacral radiculopathy.

AIM

To evaluate postoperative patterns of pain and disability in patients undergoing spinal discectomy.

METHODS AND MATERIALS

This investigation was a retrospective longitudinal review of prospective information gathered from 543 enrolled patients for lumbar radiculoplasty. The study participants were divided into two categories: Category 1 (SDS) comprising patients of lumbar radiculoplasty managed with SDS (n=270) and Category 2 (non-SDS) comprising patients of lumbar radiculoplasty managed with therapy other than SDS (n=273). It included study participants taking medication for pain control including opioids and non-opioids and physiotherapy for strengthening lower back muscles. At baseline, three months, 12 months, and 24 months after surgery, patient-reported information was gathered. Leg pain magnitude, back pain magnitude, and pain-related impairment were the key outcome metrics of interest.

RESULTS

The mean postoperative visual analog scale (VAS) score for leg pain at three-month follow-up was 4.3±1.2 in study participants in SDS and 8.1±1.3 in the non-SDS category. The VAS score was lower in the SDS category showing greater reduction in postoperative pain with statistically meaningful results (p<0.001). The mean postoperative VAS score at 12-month follow-up was 2.8±1.1 in study participants in SDS and 7.9±1.5 in the non-SDS category. The VAS score was lower in the SDS category showing greater reduction in postoperative pain with statistically meaningful results (p<0.001). The mean postoperative VAS score at 24-month follow-up was 1.7±1.2 in study participants in SDS and 7.1±1.1 in the non-SDS category. The VAS score was lower in the SDS category showing greater reduction in postoperative pain with statistically meaningful results (p<0.001).

CONCLUSION

 It was observed that after discectomy, patients suffering from lumbar radiculopathy have significant pain and disability recovery. According to these results, only a small percentage of individuals exhibit negative results at the level of impairment.

Can extracellular vesicles be considered as a potential frontier in the treatment of intervertebral disc disease?

As a global public health problem, low back pain (LBP) caused by intervertebral disc degeneration (IDD) seriously affects patients' quality of life. In addition, the prevalence of IDD tends to be younger, which brings a huge burden to individuals and society economically. Current treatments do not delay or reverse the progression of IDD. The emergence of biologic therapies has brought new hope for the treatment of IDD. Among them, extracellular vesicles (EVs), as nanoscale bioactive substances that mediate cellular communication, have now produced many surprising results in the research of the treatment of IDD. This article reviews the mechanisms and roles of EVs in delaying IDD and describes the prospects and challenges of EVs.

Pathogenesis and therapeutic implications of matrix metalloproteinases in intervertebral disc degeneration: A comprehensive review

Intervertebral disc (IVD) degeneration (IDD) is a common disorder that affects the spine and is a major cause of lower back pain (LBP). The extracellular matrix (ECM) is the structural foundation of the biomechanical properties of IVD, and its degradation is the main pathological characteristic of IDD. Matrix metalloproteinases (MMPs) are a group of endopeptidases that play an important role in the degradation and remodeling of the ECM. Several recent studies have shown that the expression and activity of many MMP subgroups are significantly upregulated in degenerated IVD tissue. This upregulation of MMPs results in an imbalance of ECM anabolism and catabolism, leading to the degradation of the ECM and the development of IDD. Therefore, the regulation of MMP expression is a potential therapeutic target for the treatment of IDD. Recent research has focused on identifying the mechanisms by which MMPs cause ECM degradation and promote IDD, as well as on developing therapies that target MMPs. In summary, MMP dysregulation is a crucial factor in the development of IDD, and a deeper understanding of the mechanisms involved is needed to develop effective biological therapies that target MMPs to treat IDD.

Rescuing Nucleus Pulposus Cells From Senescence via Dual-Functional Greigite Nanozyme to Alleviate Intervertebral Disc Degeneration

High levels of reactive oxygen species (ROS) lead to progressive deterioration of mitochondrial function, resulting in tissue degeneration. In this study, ROS accumulation induced nucleus pulposus cells (NPCs) senescence is observed in degenerative human and rat intervertebral disc, suggesting senescence as a new therapeutic target to reverse intervertebral disc degeneration (IVDD). By targeting this, dual-functional greigite nanozyme is successfully constructed, which shows the ability to release abundant polysulfides and presents strong superoxide dismutase and catalase activities, both of which function to scavenge ROS and maintain the tissue at physical redox level. By significantly lowering the ROS level, greigite nanozyme rescues damaged mitochondrial function in IVDD models both in vitro and in vivo, rescues NPCs from senescence and alleviated the inflammatory response. Furthermore, RNA-sequencing reveals ROS-p53-p21 axis is responsible for cellular senescence-induced IVDD. Activation of the axis abolishes greigite nanozyme rescued NPCs senescence phenotype, as well as the alleviated inflammatory response to greigite nanozyme, which confirms the role of ROS-p53-p21 axis in greigite nanozyme's function to reverse IVDD. In conclusion, this study demonstrates that ROS-induced NPCs senescence leads to IVDD and the dual-functional greigite nanozyme holds strong potential to reverse this process, providing a novel strategy for IVDD management.

Polydopamine Nanoparticles Targeting Ferroptosis Mitigate Intervertebral Disc Degeneration Via Reactive Oxygen Species Depletion, Iron Ions Chelation, and GPX4 Ubiquitination Suppression

Intervertebral disc degeneration (IVDD)-induced lower back pain (LBP) is a common problem worldwide. The underlying mechanism is partially accredited to ferroptosis, based on sequencing analyses of IVDD patients from the gene expression omnibus (GEO) databases. In this study, it is shown that polydopamine nanoparticles (PDA NPs) inhibit oxidative stress-induced ferroptosis in nucleus pulposus (NP) cells in vitro. PDA NPs scavenge reactive oxygen species (ROS), chelate Fe²⁺ to mitigate iron overload, and regulate the expression of iron storage proteins such as ferritin heavy chain (FHC), ferritin, and transferrin receptor (TFR). More importantly, PDA NPs co-localize with glutathione peroxidase 4 (GPX4) around the mitochondria and suppress ubiquitin-mediated degradation, which in turn exerts a protective function via the transformation and clearance of phospholipid hydroperoxides. PDA NPs further down-regulate malondialdehyde (MDA) and lipid peroxide (LPO) production; thus, antagonizing ferroptosis in NP cells. Moreover, PDA NPs effectively rescue puncture-induced degeneration in vivo by targeting ferroptosis and inhibiting GPX4 ubiquitination, resulting in the upregulation of antioxidant pathways. The findings offer a new tool to explore the underlying mechanisms and a novel treatment strategy for IVDD-induced LBP.

Changing trends of the disease burden of non-rheumatic valvular heart disease in China from 1990 to 2019 and its predictions: Findings from global burden of disease study

Objective

China has an increasing burden of non-rheumatic valvular heart disease (NRVHD) as the aging of the population is deepening. The aim was to assess the age and sex-specific prevalence and DALYs of NRVHD in China from 1990 to 2019 and to predict the burden in the next 25 years.

Methods

The Global Burden of Disease Study (2019) was used to extract the data of age- and sex-specific incidence, mortality, and disability-adjusted life years (DALYs) of NRVHD in China, 1990-2019. We estimated the annual percentage change (EAPC) to access the temporal trends of the disease burden of NRVHD. The R package called Nordpred was used to perform an age-period-cohort analysis to predict the prevalence of NRVHD in the next 25 years.

Results

The number of incident cases of NRVHD increased from 93.16 thousand in 1990 to 325.05 thousand in 2019. Overall upward trends were observed in the age-standardized incidence rate (ASIR) from 1990 to 2019. Significant temporal trends in mortality and DALYs of NRVHD were observed. High systolic blood pressure, high sodium diet, and lead exposure were the main driving forces for NRVHD. In the next 25 years, the number of new cases and deaths of NRVHD should continue to increase to 390.64 thousand and 10.0 thousand, respectively. The ASIR should show an upward trend, while the ASMR should show a downward trend among men and women.

Conclusion

In China, the overall rates of NRVHD have increased over the past 30 years, and there has been a substantial increase in the burden of NRVHD due to population growth and aging and will continue to increase in the next 25 years. Our results can help shape a multifactorial approach and public policy to reduce the NRVHD burden throughout China.

Postural Control of Patients with Low Back Pain Under Dual-Task Conditions

Low back pain is a major global public health problem, but the current intervention effect is not ideal. A large body of previous literature suggests that patients with chronic low back pain may have abnormal postural control, which is more evident in the dual task situation. In recent years, research on postural control in patients with low back pain under dual-task conditions has gradually become a hot topic. However, the results obtained from these studies were not entirely consistent. In this review, we summarized relevant studies on the performance of postural control in patients with low back pain under dual-task conditions, analyze it from the perspective of the theoretical model of dual-task interaction, the specific research paradigm of dual task, the performance of postural control, and the related factors affecting postural control performance, etc. It was reasonable to assume that patients with low back pain might have a certain degree of abnormal postural control, and this abnormality was affected by comprehensive factors such as age, cognitive resource capacity, attention needs, complex sensorimotor integration, external environment, etc. Furthermore, postural control performance in low back pain patients under dual-task conditions was further influenced by the nature and complexity of the different tasks. In general, the more attention resources were needed, the external environmental conditions were worse, and the age-related functions were degenerate, etc., the weaker posture control ability was. In short, a deeper understanding of postural control in patients with low back pain under dual-task conditions may shed light on more references for the rehabilitation and management of low back pain, as well as some new ideas for scientific research on cognition and postural control.

Residents of Mountainous Areas Have a Higher Low Back Pain Prevalence Than Flat Areas of Chongqing, China: A Cross-Sectional Study

Background and Purpose

Epidemiological studies on low back pain in residents living in mountainous areas are scarce. The study was aimed at investigating the prevalence and associated factors of low back pain in Chongqing, relatively impoverished mountainous areas of China.

Materials and Methods

This was a cross-sectional study conducted at selected community or village health service centers in Chongqing over a 2-month period (May 2021 to June 2021), which included adults of Chongqing aged >18 years with or without low back pain (N=1820) chosen by stratified, cluster-sampling. Associated factors of low back pain including sociodemographic characteristics, lifestyle, and occupational features were collected, along with medical history, Oswestry Disability Questionnaire (ODI), and Numerical Rating Scale (NRS) of patients with low back pain, and carried out for at least 20 minutes per respondent. Univariate and multivariate logistic regression models were utilized for statistical analysis.

Results

Overall, 30.5% of 1704 respondents presented with low back pain, with 26.3% living in flat areas and 35.6% in mountainous areas. The associated factors of low back pain were mountainous area residence (OR 1.4, 95% CI 1.1-1.8), advanced age (OR 1.8, 95% CI 1.3-2.5 for those aged 45-59 years, OR 2.3, 95% CI 1.6-3.4 for those aged 60-74 years, and OR 2.1, 95% CI 1.2-3.6 for those aged ≥75 years), married or remarried (OR 1.9, 95% CI 1.1-3.2), divorced or widowed (OR 2.7, 95% CI 14-5.4), moderate labor intensity (OR 1.4, 95% CI 1.1-1.8), frequent stoop (OR 1.6, 95% CI 1.1-2.4), and depressed mood (OR 1.6, 95% CI 1.2-2.1). Residents in the mountainous areas had a higher score on Oswestry Disability Questionnaire (8.3 [SD 6.3] vs 6.2 [SD 4.3]) than those in flat areas.

Conclusion

Mountainous areas in Chongqing had higher prevalence of low back pain as 35.6%, compared with 26.3% in flat areas, with more severe dysfunction in low back pain patients. Multifactorial analysis found that the factors associated with low back pain in Chongqing residents included mountain residence, labor intensity, stoop, psychological factors and frequency of exercise.

Design and evaluation of a parallel mechanism for wearable lumbar support exoskeleton

BACKGROUND

Work-related musculoskeletal disorders (WMSDs) are a serious problem, and manual material handling (MMH) tasks remain common in most industries. Thus, a lightweight and active exoskeleton is needed.

OBJECTIVE

A facile, convenient, multifunctional, wearable lumbar support exoskeleton (WLSE) was proposed to relieve the muscular tension and fatigue especially in the way of WMSDs.

METHOD

Based on the screw theory and virtual power principle, the parallel structure was used as the scheme choice for selecting suitable actuators and joints. The exoskeleton, which was characterized by high adaptability and complied with human motion, included branch unit, mechanism branch units, control units and sensors. Furthermore, using surface electromyography (sEMG) signal evaluation, an experiment which contains several tests was designed to evaluate whether WLSE had effect on supporting and reliving muscular fatigue while lifting-up different weight of objects under wearing without traction (T1) and wearing with traction (T2).

RESULTS

Data collected were analyzed statistically by the two-way ANOVA. It showed that the RMS of sEMG was obviously reduced while carrying the heavy objects with WLSE under T2, and the MF values always performed the decreasing trend in T2/T1.

CONCLUSION

This paper proposed a facile, convenient, multifunctional WLSE. From the results, it was concluded that the WLSE was significantly effective in reliving the muscle tension and muscle fatigue while lifting to prevent and treat WMSDs.

Bibliometric and visual analysis of research on the links between the gut microbiota and pain from 2002 to 2021

BACKGROUND AND AIMS

The gut microbiota is involved in the regulation of pain, which is proved by plenty of evidence. Although a substantial quantity of research on the link between the gut microbiota and pain has emerged, no study has focused on the bibliometric analysis of this topic. We aim to present a bibliometric review of publications over the past 20 years and predict research hot spots.

METHODS

Relevant publications between 2002 and 2021 were extracted from the Science Citation Index-Expanded (SCI-EXPANDED) of the Web of Science Core Collection (WoSCC) database on April 22, 2022. CiteSpace (version 5.8 R3c), VOSviewer, the Online Analysis Platform of Literature Metrology, and the R package bibliometrix were used to analyze and visualize.

RESULTS

A total of 233 articles have been published between 2002 and 2021. The number of publication outputs increased rapidly since 2016. The collaboration network revealed that the USA, Baylor College of Medicine, and Vassilia Theodorou were the most influential country, institute, and scholar, respectively. Alimentary pharmacology and therapeutics and Gut were the most co-cited journal and Neurogastroenterology and Motility was the most productive journal. Visceral sensitivity, fibromyalgia, gastrointestinal, chronic pain, stress, gut microbiome, LGG, brain-gut axis, SLAB51, and sequencing were the top 10 clusters in co-occurrence cluster analysis. Keyword burst detection indicated that the brain-gut axis and short-chain fatty acid were the current research hot spots.

CONCLUSION

Research on the links between the gut microbiota and pain has increased rapidly since 2016. The current research focused on the brain-gut axis and short-chain fatty acid. Accordingly, the SCFAs-mediated mechanism of pain regulation will be a research direction of great importance on the links between the gut microbiota and pain. This study provided instructive assistance to direct future research efforts on the links between the gut microbiota and pain.

Age and Sex in Back Pain Intensity—Retrospective Study of Conservatory vs. Surgical Discopathy Treatment

(1) Background: The frequency of back pain diagnosis and treatment has markedly increased in recent years. Back pain may be caused by many factors and discopathy is one of them. The aim of the study was to assess the impact of age and sex on back pain intensity in rehabilitated patients with discopathy treated conservatively and surgically; (2) Methods: The study included 137 patients: 96 undergoing conservative therapy and 41 after back surgery due to discopathy. VAS and the Laitinen scale were used for pain assessment. All patients underwent a multidirectional rehabilitation program at the Department of Rehabilitation and Physical Medicine of the Medical University in Łódź; (3) Results: No statistically significant effect of age and sex was observed on the level of pain intensity on VAS and the Laitinen scale; (4) Conclusions: Age and sex do not seem to affect back pain intensity in rehabilitated patients treated conservatively and surgically for discopathy. The problem requires further research on a larger group of patients.

Transcriptome profiling of microRNAs reveals potential mechanisms of manual therapy alleviating neuropathic pain through microRNA-547-3p-mediated Map4k4/NF-κb signaling pathway

BACKGROUND

Local neuroinflammation secondary to spinal nerve compression in lumbar disk herniation (LDH) is a key driver contributing to neuropathic pain. Manual therapy (MT), a widely used nonsurgical therapy, can relieve LDH-mediated pain by reducing inflammation. MT has attracted extensive attention; however, its mechanism remains poorly understood. MicroRNAs (miRNAs) are important regulators of pain signaling transduction, but are rarely reported in the chronic compression of dorsal root ganglia (CCD) model, and further investigation is needed to decipher whether they mediate anti-inflammatory and analgesic effects of MT.

METHODS

We used a combination of in vivo behavioral and molecular techniques to study MT intervention mechanisms. Neuropathic pain was induced in a CCD rat model and MT intervention was performed according to standard procedures. Enzyme-linked immunosorbent assay (ELISA) was used to detect inflammatory cytokine levels in dorsal root ganglia (DRG). Small RNA sequencing, immunofluorescence, Western blot, and qRT-PCR were performed to screen miRNAs and their target genes and determine core factors in the pathway possibly regulated by miRNA-mediated target gene in DRG of MT-treated CCD rats.

RESULTS

Compared with naive rats, small RNA sequencing detected 22 differentially expressed miRNAs in DRG of CCD rats, and compared with CCD rats, MT-treated rats presented 19 differentially expressed miRNAs, which were functionally associated with nerve injury and inflammation. Among these, miR-547-3p was screened as a key miRNA mediating neuroinflammation and participating in neuropathic pain. We confirmed in vitro that its function is achieved by directly regulating its target gene Map4k4. Intrathecal injection of miR-547-3p agomir or MT intervention significantly reduced Map4k4 expression and the expression and phosphorylation of IκBα and p65 in the NF-κB pathway, thus reducing the inflammatory cytokine levels and exerting an analgesic effect, whereas intrathecal injection of miR-547-3p antagomir led to opposite effects.

CONCLUSIONS

In rats, CCD-induced neuropathic pain leads to variation in miRNA expression in DRG, and MT can intervene the transcription and translation of inflammation-related genes through miRNAs to improve neuroinflammation and alleviate neuropathic pain. MiR-547-3p may be a key target of MT for anti-inflammatory and analgesia effects, which is achieved by mediating the Map4k4/NF-κB pathway to regulate downstream inflammatory cytokines.

Time Trends in the Incidence of Spinal Pain in China, 1990 to 2019 and Its Prediction to 2030: The Global Burden of Disease Study 2019

BACKGROUND

With increasing life expectancy in China, the associated burden of low back and neck pain (spinal pain) on the healthcare system increases, posing a substantial public health challenge. This study aimed to investigate trends in spinal pain incidence across China from 1990 to 2019 and to predict incidence trends between 2020 and 2030.

METHODS

Data were derived from the Global Burden of Disease Study (GBD) 2019. The annual percentage change (APC) and average annual percentage change (AAPC) between 1990 and 2019 were calculated using Joinpoint regression analysis. The effects of age, period, and cohort on spinal pain were estimated by an age-period-cohort model. An autoregressive integrated moving average (ARIMA) model was used to forecast incidence trends from 2020 to 2030.

RESULTS

From 1990 to 2019, the age-standardized incidence rate (ASIR) of low back pain (LBP) significantly decreased in both male and female subjects, while the ASIR of neck pain (NP) slightly increased regardless of sex. Joinpoint regression analysis showed that the incidence rates of LBP decreased in all age groups, and incidence rates of NP increased after 45 years old among men and women. The age effects showed that the relative risks (RR) of LBP incidence increased with age, and the group aged 40-49 years had the highest RR for NP incidence, regardless of sex. Period effects showed that the risk of NP continuously increased with increasing time periods, but not in LBP. The cohort effect showed a continuously decreasing trend in later birth cohorts. The prediction results of the ARIMA model show that the ASIR of NP in both male and female subjects in China shows an increasing trend in the next 10 years, and the ASIR of LBP increased in male but decreased in female subjects.

CONCLUSION

Spinal pain has remained a major public health burden over the past 30 years in China and will likely increase further with population aging. Therefore, spinal pain should be a priority for future research on prevention and therapy, and is especially critical as the aging population increases in China.

Quantifying the stiffness of lumbar erector spinae during different positions among participants with chronic low back pain

Objective

The purposes of this study were to (1) detect the intra- and inter-reliabilities of the lumbar erector spinae stiffness by MyotonPRO among participants with chronic lower back pain (CLBP); (2) compare the muscle stiffness between pain and non-pain sides during different positions; (3) explore the correlation between intensity of pain and muscle stiffness.

Design

Twenty participants with CLBP were recruited and the stiffness measurements were carried out by two experienced physiotherapists (operators Ⅰ and Ⅱ). Each participant was evaluated by the operatorⅠ in different postures (static prone and sitting). After a 5-day interval, the same participant was reassessed by the operatorⅠ in the static prone posture. For the inter-rater reliability test, each participant was quantified by both operators once, with 30 minutes between the measurements on the same day. The intensity of pain was evaluated using a 0–10 visual analog scale (VAS).

Results

The intra- and inter-rater reliabilities were excellent (ICC = 0.88–0.99). The MDC values ranged from 25.03 to 86.26 N/m. Examples of Bland-Altman plots showed good agreement. The erector spinae stiffness on the painful sides was higher with a marked increase in the sitting position (P < .05) when compared with the non-painful side. However, there was no significant difference in the prone position (P > .05). The intensity of pain among adults with CLBP was not associated with muscle stiffness of the lumbar erector spinae muscle.

Conclusions

Our findings indicated that the MyotonPRO is a feasible device in quantifying the stiffness of the lumbar erector spinae muscle in patients with CLBP. Meanwhile, the erector spinae stiffness on the painful sides was higher in the sitting when compared with the non-painful side.

Curcumenol Mitigates the Inflammation and Ameliorates the Catabolism Status of the Intervertebral Discs In Vivo and In Vitro via Inhibiting the TNFα/NFκB Pathway

Low back pain (LBP) caused by intervertebral disc degeneration (IVDD) is accredited to the release of inflammatory cytokines followed by biomechanical and structural deterioration. In our study, we used a plant-derived medicine, curcumenol, to treat IVDD. A cell viability test was carried out to evaluate the possibility of using curcumenol. RNA-seq was used to determine relative pathways involved with curcumenol addition. Using TNFα as a trigger of inflammation, the activation of the NF-κB signaling pathway and expression of the MMP family were determined by qPCR and western blotting. Nucleus pulposus (NP) cells and the rats’ primary NP cells were cultured. The catabolism status was evaluated by an ex vivo model. A lumbar instability mouse model was carried out to show the effects of curcumenol in vivo. In general, RNA-seq revealed that multiple signaling pathways changed with curcumenol addition, especially the TNFα/NF-κB pathway. So, the NP cells and primary NP cells were induced to suffer inflammation with the activated TNFα/NF-κB signaling pathway and increased expression of the MMP family, such as MMP3, MMP9, and MMP13, which would be mitigated by curcumenol. Owing to the protective effects of curcumenol, the height loss and osteophyte formation of the disc could be prevented in the lumbar instability mouse model in vivo.

Anxiety Symptoms and Associated Factors Among Chronic Low Back Pain Patients in China: A Cross-Sectional Study

Background

This study aimed to investigate the prevalence of anxiety symptoms among patients with chronic low back pain and explore its related factors.

Methods

A cross-sectional study was conducted on patients with chronic low back pain from two general hospitals in China. Anxiety symptoms were assessed by the Generalized Anxiety Disorder-7. Binary logistic regression was used to examine the association between demographic characteristics, pain severity, pain self-efficacy, family functioning and anxiety symptoms.

Results

This study involved 1,172 chronic low back pain patients, with an effective rate of 94.67%. The prevalence of anxiety symptoms among patients with chronic low back pain in China was 23.89%. In the binary logistic regression, patients with more severe pain (OR = 1.15, 95%CI: 1.11–1.18) and pain duration between 1~5 years (1~3 years: OR = 2.45, 95%CI: 1.38–4.36; 3~5 years: OR = 2.99, 95%CI: 1.49–6.00) had a higher risk to anxiety symptoms. In contrast, patients with higher monthly income (OR = 0.62, 95%CI: 0.39–0.98), better family functioning (highly functional family: OR = 0.22, 95% CI: 0.13–0.37; moderately dysfunctional family: OR = 0.44, 95% CI: 0.27–0.72) and higher pain self-efficacy (OR = 0.95, 95%CI: 0.94–0.96) had a lower risk to anxiety symptoms.

Conclusion

The prevalence of anxiety symptoms among chronic low back pain patients was high in China. Targeted intervention measures should be taken to reduce anxiety symptoms levels of chronic low back pain patients.

Disability burden due to musculoskeletal conditions and low back pain in Australia: findings from GBD 2019

BACKGROUND

To report the national prevalence, years lived with disability (YLDs) and attributable risk factors for all musculoskeletal conditions and separately for low back pain (LBP), as well as compare the disability burden related to musculoskeletal with other health conditions in Australia in 2019.

METHODS

Global Burden of Disease (GBD) 2019 study meta-data on all musculoskeletal conditions and LBP specifically were accessed and aggregated. Counts and age-standardised rates, for both sexes and across all ages, for prevalence, YLDs and attributable risk factors are reported.

RESULTS

In 2019, musculoskeletal conditions were estimated to be the leading cause of YLDs in Australia (20.1%). There were 7,219,894.5 (95% UI: 6,847,113-7,616,567) prevalent cases of musculoskeletal conditions and 685,363 (95% UI: 487,722-921,471) YLDs due to musculoskeletal conditions. There were 2,676,192 (95% UI: 2,339,327-3,061,066) prevalent cases of LBP and 298,624 (95% UI: 209,364-402,395) YLDs due to LBP. LBP was attributed to 44% of YLDs due to musculoskeletal conditions. In 2019, 22.3% and 39.8% of YLDs due to musculoskeletal conditions and LBP, respectively, were attributed to modifiable GBD risk factors.

CONCLUSIONS

The ongoing high burden due to musculoskeletal conditions impacts Australians across the life course, and in particular females and older Australians. Strategies for integrative and organisational interventions in the Australian healthcare system should support high-value care and address key modifiable risk factors for disability such as smoking, occupational ergonomic factors and obesity.

Prussian Blue Nanoparticles Stabilize SOD1 from Ubiquitination-Proteasome Degradation to Rescue Intervertebral Disc Degeneration

Discography often destroys the hypoxic environment in the intervertebral disc and accelerates intervertebral disc degeneration (IVDD). Therefore, it often fails to meet the requirements for application in clinical practice. This technology mainly increases the reactive oxygen species (ROS) in the IVD. As so, it is particularly critical to develop strategies to avoid this degeneration mechanism. Prussian blue nanoparticles (PBNPs) are found to enhance development under magnetic resonance T1 and have antioxidant enzyme activity. The key results of the present study confirm that PBNPs alleviate intracellular oxidative stress and increase the intracellular activities of antioxidant enzymes, such as superoxide dismutase 1 (SOD1). PBNPs can rescue nucleus pulposus cell degeneration by increasing oxidoreductase system-related mRNA and proteins, especially by stabilizing SOD1 from ubiquitination-proteasome degradation, thus improving the mitochondrial structure to increase antioxidation ability, and finally rescuing ROS-induced IVDD in a rat model. Therefore, it is considered that PBNPs can be a potential antioxidation-protective discography contrast agent.

Prevalence of Sarcopenia in Pain Patients and Correlation Between the 2 Conditions: A Systematic Review and Meta-analysis

OBJECTIVES

Sarcopenia is a generalized and progressive skeletal muscle disorder and has been proven to be associated with many diseases; however, the correlation between sarcopenia and pain has not yet been systematically clarified. This review aimed to investigate the prevalence of sarcopenia in patients with pain and to ascertain whether pain is independently associated with sarcopenia.

DESIGN

Systematic review and meta-analysis.

SETTING AND PARTICIPANTS

A systematic literature search was performed from the Cochrane Central Register of Controlled Trials, Embase, MEDLINE and Epub Ahead of Print, In-Process, In-Data-Review, and Other Non-Indexed Citations, Daily and Versions for observational studies from inception until February 2021, and our search was updated on December 31, 2021.

METHODS

Sarcopenia prevalence was calculated according to the corresponding number of patients with sarcopenia and pain. We performed meta-analyses with random effects models to calculate the pooled prevalence of sarcopenia in pain and its correlations. Subgroup analyses were also performed based on pain classification, pain location, and diagnostic criteria for sarcopenia. Heterogeneity between the studies was described using the I² statistic.

RESULTS

Fourteen observational studies (13,953 participants, 44% women, and mean age from 40.1 to 76.6 years) were included. Study quality was rated moderate to high. The overall sarcopenia prevalence in patients with pain was 0.11 (95% CI 0.07-0.15, P < .001; I² = 92.3%). People with pain were independently associated with a higher risk of sarcopenia than those without pain (odds ratio [OR] 1.35; 95% CI 1.17-1.56; P = .025; I² = 51.1%). Subgroup analyses showed that the cumulative prevalence and effect measures of sarcopenia were increased when individuals suffered secondary musculoskeletal pain (Prevalence = 12%; OR 1.45; 95% CI 1.19-1.78) and low back pain (Prevalence = 21%; OR 1.95; 95% CI 1.22-3.12).

CONCLUSIONS AND IMPLICATIONS

The prevalence of sarcopenia in patients with pain is relatively high, and pain is significantly associated with sarcopenia in older adults. Attention is needed to screen sarcopenia among patients with pain and optimize its early detection and management in clinical practice.

Epidemiological trends of low back pain at the global, regional, and national levels

Purpose

We aimed to assess the global, regional, and national burdens of low back pain (LBP) from 1990 to 2019 by gender, age, and the sociodemographic index (SDI) from the Global Burden of Disease (GBD) 2019 study.

Methods

The number of incident cases, disability-adjusted life years (DALYs), age-standardized incidence rates, and age-standardized DALY rates during 1990–2019 were obtained from the GBD 2019 study. The estimated annual percentage changes (EAPCs) in the age-standardized incidence rates and age-standardized DALY rates were determined to measure the temporal trends of LBP.

Results

In 2019, there were an estimated 223.5 million cases of LBP and 63.7 million LBP-related DALYs worldwide. During 1990–2019, the age-standardized incidence rate [EAPC =  − 0.41; 95% confidence interval (CI) − 0.46 to − 0.36] and age-standardized DALY rate decreased (EAPC =  − 0.51; 95% CI − 0.56 to − 0.46) globally. The age-standardized incidence rate of LBP decreased the most in low-middle SDI regions. The age-standardized incidence rate of LBP decreased the most in South Asia (EAPC, − 1.51), East Asia (EAPC, − 0.68), and Australasia (EAPC, − 0.26). The incidence in male subjects was lower than that in female subjects. The largest decreases in the age-standardized incidence rate and age-standardized DALY rate of LBP were observed in India, and China.

Conclusions

The global age-standardized incidence rate and age-standardized DALY rate of LBP showed a downward trend, especially in East and South Asia. In addition, a heavier burden of LBP was observed in older and female populations.

Association of Lumbar MRI Findings with Current and Future Back Pain in a Population-based Cohort Study

STUDY DESIGN

Population-based cohort study.

OBJECTIVE

We examined associations between common lumbar degenerative changes observed on magnetic resonance imaging (MRI) and present or future low back pain (LBP).

SUMMARY OF BACKGROUND DATA

The association between lumbar MRI degenerative findings and LBP is unclear. Longitudinal studies are sparse.

METHODS

Participants (n = 3369) from a population-based cohort study were imaged at study entry, with LBP status measured at baseline and 6-year follow-up. MRI scans were reported on for the presence of a range of MRI findings. LBP status was measured on a 0 to 10 scale. Regression models were used to estimate the cross-sectional and longitudinal associations between individual and multiple MRI findings and LBP severity. Separate longitudinal analyses were conducted for participants with and without baseline pain.

RESULTS

MRI findings were present in persons with and without back pain at baseline. Higher proportions were found in older age groups. 76.4% of participants had a least one MRI finding and 8.3% had five or more different MRI findings. Cross-sectionally, most MRI findings were slightly more common in those with LBP and pain severity was slightly higher in those with MRI findings (ranging from 0.06 for high intensity zone to 0.83 for spondylolisthesis). In the longitudinal analyses, we found most MRI findings were not associated with future LBP-severity regardless of the presence or absence of baseline pain. Compared to zero MRI findings, having multiple MRI findings (five or more) was associated with mildly greater pain-severity at baseline (0.84; 0.50-1.17) and greater increase in pain-severity over 6 years in those pain free at baseline (1.21; 0.04-2.37), but not in those with baseline pain (-0.30; -0.99 to 0.38).

CONCLUSION

Our study shows that the MRI degenerative findings we examined, individually or in combination, do not have clinically important associations with LBP, with almost all effects less than one unit on a 0 to 10 pain scale.Level of Evidence: 3.

The burden of low back pain, rheumatoid arthritis, osteoarthritis, and gout and their respective attributable risk factors in Brazil: results of the GBD 2017 study

INTRODUCTION

Musculoskeletal (MSK) disorders are a major cause of disability worldwide. Different modifiable risk factors are associated to these disorders. The objective of this study was to analyze the burden of low back pain (LBP), rheumatoid arthritis (RA), osteoarthritis (OA), and gout, attributable to risk factors, in 2017.

METHODS

The burden of LBP, RA, OA, and gout, and attributable risk factors were analyzed using data extracted from the Global Burden of Disease (GBD) Brasil-2017 study. Descriptive analysis was conducted to compare disability-adjusted life years (DALY) rates between sexes and age groups (15-49 and 50-69 years), in 2017.

RESULTS

The highest rates of DALY due to LBP were attributed to occupational ergonomic factors in the 15-49-year group, regardless of sex and males aged 50-69 years, whereas smoking was the major contributor in the 50-69-year female group. RA-related DALY rates were attributed to smoking and were higher among women aged 50-69 years. High body mass index (BMI) was the most relevant risk factor for the burden of OA, with higher rates detected in the 50-69-year group, and it was the most significant risk factor for DALY rate attributed to gout, regardless of sex or age group.

CONCLUSIONS

Occupational surveillance measures are indicated to prevent LBP. Actions to decrease smoking and overweight, and the surveillance of weight gain are warranted to decrease the burden of LBP, RA and OA, and gout, respectively. These actions will be more effective if age and sex differentials are considered in planning.

Mesenchymal Stem Cell-Derived Exosomes as a Novel Strategy for the Treatment of Intervertebral Disc Degeneration

Intervertebral disc degeneration (IVDD) has been reported to be the most prevalent contributor to low back pain, posing a significant strain on the healthcare systems on a global scale. Currently, there are no approved therapies available for the prevention of the progressive degeneration of intervertebral disc (IVD); however, emerging regenerative strategies that aim to restore the normal structure of the disc have been fundamentally promising. In the last decade, mesenchymal stem cells (MSCs) have received a significant deal of interest for the treatment of IVDD due to their differentiation potential, immunoregulatory capabilities, and capability to be cultured and regulated in a favorable environment. Recent investigations show that the pleiotropic impacts of MSCs are regulated by the production of soluble paracrine factors. Exosomes play an important role in regulating such effects. In this review, we have summarized the current treatments for disc degenerative diseases and their limitations and highlighted the therapeutic role and its underlying mechanism of MSC-derived exosomes in IVDD, as well as the possible future developments for exosomes.

Global, regional and national burden of low back pain 1990-2019: A systematic analysis of the Global Burden of Disease study 2019

BACKGROUND

To comprehensively analyze the global level and trends of prevalence, incidence and years lived with disability (YLDs) for low back pain (LBP) from 1990 to 2019 by age, sex and sociodemographic index (SDI).

METHODS

Publicly available modelled data and methods were obtained from the Global Burden of Diseases (GBD) study 2019, and used to evaluate the global burden of LBP through a systematic analysis.

RESULTS

Globally, the age-standardized prevalence, incidence and YLDs rate of LBP were slightly decreased from 1990 to 2019, but the number of the prevalent cases, incident cases and YLDs had substantially increased, and LBP remains the leading cause of YLDs in 2019 worldwide. The number of prevalent cases was increased with age and peaked at the age of 45-54 years for both sexes, and the global prevalence rate was higher in females than in males and increased with age, peaking at the 80-84 age group in both sexes in 2019. Overall, a positive association between the age-standardized YLD rate and SDI was observed over the past thirty years. At the national revel, the United States, Denmark and Switzerland had the three highest levels of age-standardized prevalence, while Zambia, Zimbabwe and Canada showed the highest increase in the age-standardized prevalence during 1990-2019.

CONCLUSIONS

LBP is a major public health issue globally, and its burden remains high. Increasing population awareness about its risk factors and preventive measures for LBP are needed to reduce the future burden of this condition.

THE TRANSLATIONAL POTENTIAL OF THIS ARTICLE

Due to the high prevalence and heavy burden of LBP globally, it is important to update its epidemiological data. This systematic analysis provides researchers and healthcare policy makers with up-to-date, comprehensive and comparable information on global LBP burden, which is of clinical translational significance.

Prevalence and factors associated with comorbid depressive symptoms among people with low back pain in China: A cross-sectional study

BACKGROUND

Low back pain is a common medical condition among the general population that is associated with many adverse health effects when comorbid with depressive symptoms. However, little is known about depressive symptoms in the population with low back pain in China. Our study evaluated the prevalence of depressive symptoms and analyzed the factors associated with this condition in the Chinese population with low back pain.

METHODS

We conducted a cross-sectional analysis of data from the 2018 China Health and Retirement Longitudinal Study. We collected low back pain information for each participant and identified depressive symptoms using the brief version of the Center for Epidemiologic Studies Depression Scale. A wide range of sociodemographic and health-related characteristics of the subjects were extracted. We measured the prevalence of depressive symptoms comorbid with low back pain and analyzed the associated factors by multiple logistic regression.

RESULTS

A total of 5,779 respondents aged 45 and over with low back pain formed the sample, 41.8% of whom reported depressive symptoms. Multiple logistic regression analysis indicated greater vulnerability to depressive symptoms among females (OR = 1.41, 95% CI, 1.16-1.73), relatively younger persons (60-74 years: OR = 0.72, 95% CI, 0.63-0.83; ≥ 75 years: OR = 0.62, 95% CI, 0.49-0.79, reference: 45-59 years), those from the central and western regions (central: OR = 1.39, 95% CI, 1.18-1.64; western: OR = 1.56, 95% CI, 1.33-1.83), participants with extremely short sleep duration (OR = 2.74, 95% CI, 2.33-3.23), those with poor self-perceived health status (OR = 2.91, 95% CI, 2.34-3.63,), multisite pain (OR = 1.54, 95% CI, 1.20-1.98) and disability in activities of daily living (Basic: OR = 1.70, 95% CI, 1.47-1.98; Instrumental: OR = 1.95, 95% CI, 1.70-2.24).

CONCLUSION

Depressive symptoms were highly prevalent in the Chinese population ≥ 45 years with low back pain. More attention should be paid to the individuals at high-risk confirmed by this study to facilitate early identification and intervention against depressive symptoms.

Can Acupuncture Improve Chronic Spinal Pain? A Systematic Review and Meta-Analysis

STUDY DESIGN

Systematic review and meta-analysis.

OBJECTIVE

To investigate the effect and safety of acupuncture for the treatment of chronic spinal pain.

METHODS

MEDLINE, EMBASE, the Cochrane Central Register of Controlled Trials (CENTRAL), Web of Science, the WHO Clinical Trial Registry, and the US National Library of Medicine clinical trial registry were searched from January 1, 2000, to November 1, 2019. Randomized controlled trials (RCTs) involving patients with chronic spinal pain treated by acupuncture versus sham acupuncture, no treatment, or another treatment were included.

RESULTS

Data was extracted from 22 RCTs including 2588 patients. Pooled analysis revealed that acupuncture can reduce chronic spinal pain compared to sham acupuncture (weighted mean difference [WMD] -12.05, 95% confidence interval [CI] -15.86 to -8.24), mediation control (WMD -18.27, 95% CI -28.18 to -8.37), usual care control (WMD -9.57, 95% CI -13.48 to -9.44), and no treatment control (WMD -17.10, 95% CI -24.83 to -9.37). In terms of functional disability, acupuncture can improve physical function at immediate-term follow-up (standardized mean difference [SMD] -1.74, 95% CI -2.04 to -1.44), short-term follow-up (SMD -0.89, 95% CI -1.15 to -0.62), and long-term follow-up (SMD -1.25, 95% CI -1.48 to -1.03).

CONCLUSION

In summary, compared to no treatment, sham acupuncture, or conventional therapy such as medication, massage, and physical exercise, acupuncture has a significantly superior effect on the reduction in chronic spinal pain and function improvement. Acupuncture might be an effective treatment for patients with chronic spinal pain and it is a safe therapy.

Neuroscience20 (BRAIN20, SPINE20, and MENTAL20) Health Initiative: A Global Consortium Addressing the Human and Economic Burden of Brain, Spine, and Mental Disorders Through Neurotech Innovations and Policies

Neurological disorders significantly impact the world's economy due to their often chronic and life-threatening nature afflicting individuals which, in turn, creates a global disease burden. The Group of Twenty (G20) member nations, which represent the largest economies globally, should come together to formulate a plan on how to overcome this burden. The Neuroscience-20 (N20) initiative of the Society for Brain Mapping and Therapeutics (SBMT) is at the vanguard of this global collaboration to comprehensively raise awareness about brain, spine, and mental disorders worldwide. This paper aims to provide a comprehensive review of the various brain initiatives worldwide and highlight the need for cooperation and recommend ways to bring down costs associated with the discovery and treatment of neurological disorders. Our systematic search revealed that the cost of neurological and psychiatric disorders to the world economy by 2030 is roughly $16T. The cost to the economy of the United States is $1.5T annually and growing given the impact of COVID-19. We also discovered there is a shortfall of effective collaboration between nations and a lack of resources in developing countries. Current statistical analyses on the cost of neurological disorders to the world economy strongly suggest that there is a great need for investment in neurotechnology and innovation or fast-tracking therapeutics and diagnostics to curb these costs. During the current COVID-19 pandemic, SBMT, through this paper, intends to showcase the importance of worldwide collaborations to reduce the population's economic and health burden, specifically regarding neurological/brain, spine, and mental disorders.

Burden of valvular heart disease, 1990-2017: Results from the Global Burden of Disease Study 2017

Background

Valvular heart disease (VHD) is expected to cause an increase in public-health problems in the coming years, especially in elderly populations. We aim to estimate the incidence, mortality, and burden of VHD, by age, from 1990 to 2017 in 195 countries and territories.

Methods

We estimated the incidence, mortality, and burden of VHD based on the Global Burden of Disease Study 2017. All metrics are presented with their 95% uncertainty intervals (UIs). The Socio-demographic Index was used to identify whether developmental status correlates with health outcomes.

Results

The global incidence of rheumatic heart disease (RHD) decreased by 8.67% between 1990 and 2017, while that of non-rheumatic VHD (NRVHD) increased by 45.10%. There was a 54.00% decrease in age-standardized death rate (ASDR) for RHD, but a small and non-significant decrease (-3.00%) in the ASDR for NRVHD. The global age-standardized disability-adjusted life years (DALY) rate of RHD decreased by 53.52%, while there was a 12.62% reduction in the age-standardized DALY rate of NRVHD.

Conclusions

The burden from different VHDs demonstrated a diverse change at a global level between 1990 and 2017. Although RHD burden has an obvious means of mitigation, a substantially high incidence of NRVHD was observed over this time period, especially in the elderly, which may lead to high health care costs and signify the potential for even higher costs in the future.

Diagnostic Role of Magnetic Resonance Imaging in Low Back Pain Caused by Vertebral Endplate Degeneration

Low back pain (LBP) is a common health issue worldwide with a huge economic burden on healthcare systems. In the United States alone, the cost is estimated to be $100 billion each year. Intervertebral disc degeneration is considered one of the primary causes of LBP. Moreover, the critical role of the vertebral endplates in disc degeneration and LBP is becoming apparent. Endplate abnormalities are closely correlated with disc degeneration and pain in the lumbar spine. Imaging modalities such as plain film radiography, computed tomography, and fluoroscopy are helpful but not very effective in detecting the causes behind LBP. Magnetic resonance imaging (MRI) can be used to acquire high-quality three-dimensional images of the lumbar spine without using ionizing radiation. Therefore, it is increasingly being used to diagnose spinal disorders. However, according to the American College of Radiology, current referral and justification guidelines for MRI are not sufficiently clear to guide clinical practice. This review aimed to evaluate the role of MRI in diagnosing LBP by considering the correlative contributions of vertebral endplates. The findings of the review indicate that MRI allows for fine evaluations of endplate morphology, endplate defects, diffusion and perfusion properties of the endplate, and Modic changes. Changes in these characteristics of the endplate were found to be closely correlated with disc degeneration and LBP. The collective evidence from the literature suggests that MRI may be the imaging modality of choice for patients suffering from LBP. LEVEL OF EVIDENCE: 1 TECHNICAL EFFICACY STAGE: 3.

[Research progress of endogenous repair strategy in intervertebral disc]

Objective

To review the research progress of endogenous repair strategy (ERS) in intervertebral disc (IVD).

Methods

The domestic and foreign literature related to ERS in IVD in recent years was reviewed, and its characteristics, status, and prospect in the future were summarized.

Results

The key of ERS in IVD is to improve the vitality of stem/progenitor cells in IVD or promote its migration from stem cell Niche to the tissue that need to repair. These stem/progenitor cells in IVD are derived from nucleus pulposus, annulus fibrosus, and cartilaginous endplate, showing similar biological characteristics to mesenchymal stem cells including the expression of the specific stem/progenitor cell surface markers and gene, and also the capacity of multiple differentiations potential. However, the development, senescence, and degeneration of IVD have consumed these stem/progenitor cells, and the harsh internal microenvironment further impair their biological characteristics, which leads to the failure of endogenous repair in IVD. At present, relevant research mainly focuses on improving the biological characteristics of endogenous stem/progenitor cells, directly supplementing endogenous stem/progenitor cells, biomaterials and small molecule compounds to stimulate the endogenous repair in IVD, so as to improve the effect of endogenous repair.

Conclusion

At present, ERS has gotten some achievements in the treatment of IVD degeneration, but its related studies are still in the pre-clinical stage. So further studies regarding ERS should be carried out in the future, especially in vivo experiments and clinical transformation.

Neck pain is the leading cause of disability burden in China: Findings from the Global Burden of Disease Study 2017

Background

Neck pain (NP) is a common musculoskeletal problem; however, the prevalence and years lived with disability (YLD) of NP in China are still unclear. This study sought to estimate the age-, sex- and province-specific prevalence and YLD of NP in China.

Methods

Adopting the methodology framework and analytical strategies used in the Global Burden of Disease (GBD), Injuries, and Risk Factors Study (2017), the prevalence and YLD of NP in China were estimated by age, sex, year, and provinces/regions.

Results

In China, the age-standardized point prevalence rate of NP was 4,532.6 per 100,000 persons in 1990 and increased slightly to 4,634.4 per 100,000 persons in 2017. The prevalence of NP was 48.0 million in 1990 and rose dramatically to 87.3 million in 2017 (an increase of 82.0%). The age-standardized YLD rate of NP was 454.0 per 100,000 persons in 1990, and there was a slight increase to 465.6 per 100,000 persons in 2017. The all-age YLD of NP was 4.8 million in 1990 and rose to 8.8 million in 2017 (which represents an increase of 81.1%). In 1990, NP was the third leading cause of YLD in China, and in 2017, NP was the leading cause of disability burden.

Conclusions

This study estimated the prevalence and disability burden of NP in China. NP is currently the leading cause of disability burden in China; however, it is currently inadequately recognized and should receive further attention and be subject to further research.

Multidisciplinary programme for rehabilitation of chronic low back pain - factors predicting successful return to work

Background

There are no clear indicators for predicting return to work for patients with chronic low back pain (LBP). We aim to report the outcomes of a 14-week multidisciplinary programme targeting patients with chronic LBP who failed conventional physiotherapy to provide functional rehabilitation. Also, this study will identify factors predicting successful return to work (RTW).

Methods

A collected cohort of patients with chronic LBP was consecutively enrolled into the programme from 1996 to 2014. All recruited patients failed to RTW despite at least 3 months of conservative treatment. Patient underwent weekly multidisciplinary sessions with physiotherapists, occupational therapists and clinical psychologists. Patient perceived function was considered the primary outcome of the programme. Patients were assessed for their sitting, standing and walking tolerance. Oswestry Disability Index (ODI) and Spinal Function Sort Score (SFSS) were used to assess patient perceived disability.

Results

One hundred and fifty-eight patients were recruited. After the programme, statistically significant improvement was found in ODI (47.5 to 45.0, p = 0.01) and SFSS (98.0 to 109.5, p <  0.001). There was statistically significant improvement (p <  0.01) in sitting, standing, walking tolerance and straight leg raise tests. 47.4% of the patients were able to meet their work demand. Multivariate logistic regression model (R² = 59.5%, χ² (9) = 85.640, p <  0.001) demonstrated that lower initial job demand level and higher patient-perceived back function correlated with greater likelihood of returning to work.

Conclusion

The results of this study may support the use of this multidisciplinary programme to improve patient function and return to work.

Effects of an industrial passive assistive exoskeleton on muscle activity, oxygen consumption and subjective responses during lifting tasks

The purpose of this study was to evaluate the effects of an industrial passive assisted exoskeleton (IPAE) with simulated lifting tasks on muscle activity, oxygen consumption, perceived level of exertion, local perceived pressure, and systemic usability. Eight workers were required to complete two lifting tasks with and without the IPAE, that were single lifting tasks (repeated 5 times) and 15 min repeated lifting tasks respectively. Both of the tasks required subjects to remove a toolbox from the ground to the waist height. The test results showed that IPAE significantly reduced the muscle activity of the lumbar erector spinae, thoracic erector spinae, middle deltoid and labrum-biceps muscles; the reduction effect during the 15 min lifting task was reached 21%, 12%, 32% and 38% respectively. The exoskeleton did not cause significant differences in oxygen consumption and the perceived level of exertion, but local perceived pressure on the shoulders, thighs, wrists, and waist of the subjects could be produced. 50% of the subjects rated the usability of the equipment as acceptable. The results illustrate the good potential of the exoskeleton to reduce the muscle activity of the low back and upper arms. However, there is still a concern for the obvious contact pressure.

Low expression of miR-142-3p promotes intervertebral disk degeneration

Background

Intervertebral disk degeneration (IDD) is a degenerative disease characterized by cytoplasm loss and extracellular matrix degradation. Numerous evidence reported that miRNAs participated in IDD development. Nevertheless, the function of miR-142-3p in IDD development remains unknown. This study mainly explored the potential role and function of miR-142-3p in IDD development.

Methods

One percent fetal bovine serum was used to induce the degeneration of ATDC5 cells, and miR-142-3p level was examined by qRT-PCR. Then, miR-142-3p mimic/inhibitor and its corresponding negative control were transfected into ATDC5 normal and degenerative cells. Viability, migration, invasion, apoptosis, cycle, Bax, Bcl-2, P62, and Beclin1 expression levels were assessed using CCK8, wound healing assay, annexin V-FITC/PI staining, western blot, and qRT-PCR, respectively.

Results

The results revealed that the expression levels of MMP13, ADAMTS5, MMP3, and Col-X were increased as well as the expression levels of SOX-9 and Col-II were reduced in ATDC5 degenerative cells, indicating the degeneration model was constructed. We observed that miR-142-3p was decreased in ATDC5 degenerative cells and its suppression could promote ATDC5 cell degeneration. However, miR-142-3p overexpression could reverse the cell viability inhibition, as well as apoptosis and autophagy enhancement in ATDC5 degenerative cells.

Conclusions

Our results proved that miR-142-3p may play an important role in disk degeneration. Further animal study is needed to illustrate the role of the miR-142-3p in IDD development.

Supplementary Information

The online version contains supplementary material available at 10.1186/s13018-020-02194-4.

Low back pain among Italian runners: A cross-sectional survey

BACKGROUND

Low Back Pain (LBP) is commonly reported as a very frequent disorder in sports, but its prevalence in runners remains unclear.

OBJECTIVES

To determine the prevalence of LBP in a wide sample of Italian runners.

DESIGN

A cross-sectional online survey.

SETTING

A national survey, according to the CHERRIES and STROBE guidelines, was performed in 2019.

PARTICIPANTS

2539 Italian runners.

METHODS

A sample of Italian runners registered with national running associations was recruited. The survey was conducted using an online survey development platform. The questionnaire was self-reported and included 38 questions.

MAIN OUTCOME MEASURES

Descriptive statistics and frequencies were used to analyze results. Relationships between demographics, daily habits and running characteristics and the responses given was calculated with Cramer's V. Only correlation values higher >0.60 were deemed of interest.

RESULTS

2539 questionnaires (63.5%) were valid for analysis. In total, 22.6% of runners reported having experienced LBP in the past year. Most participants (77.0%) reporting episodes of LBP believed it was not caused by running. No significant correlations (Cramer's V < 0.60) were found between LBP and demographics, training characteristics or lifestyle habits.

CONCLUSION

The prevalence of LBP among Italian runners was 22,57%. LBP was not associated with training, equipment or lifestyle.

Prevalence and Associated Factors of Depressive Symptoms Among Patients With Chronic Low Back Pain: A Cross-Sectional Study

Background: Few studies have focused on depressive symptoms among patients with chronic low back pain in China. The aim of this cross-sectional study was to assess the prevalence and associated factors of depressive symptoms in patients with chronic low back pain. Methods: From May to August 2021, 1,172 patients with chronic low back pain were recruited in China. Depressive symptoms were assessed through the Patient Health Questionnaire. Associations of demographic characteristics, clinical characters and social-psychological factors with depressive symptoms were investigated among patients with chronic low back pain. Results: The prevalence of depressive symptoms was 25.00%. Logistic regression analysis found that duration of pain in 1-5 years (1-3 years: OR = 2.91, 95%CI: 1.65-5.14, 3-5 years: OR = 3.09, 95%CI: 1.55-6.15) and more severe pain (OR = 1.13, 95%CI: 1.10-1.17) were associated with higher risks of depressive symptoms. Better family function (good family function: OR = 0.25, 95%CI: 0.15-0.41, moderate family dysfunction: OR = 0.47, 95%CI: 0.29-0.77) and higher pain self-efficacy (OR = 0.94, 95%CI: 0.93-0.95) were associated with lower risks of depressive symptoms. Conclusion: Patients with chronic low back pain have a high prevalence of depressive symptoms in China. Duration of pain, pain severity, family function and pain self-efficacy were predictors of depressive symptoms among chronic low back pain patients in China. Early identification of the associated factors may be helpful for the timely management of depressive symptoms.

Tetrahydropalmatine exerts analgesic effects by promoting apoptosis and inhibiting the activation of glial cells in rats with inflammatory pain

BACKGROUND

Pain is an unpleasant sensory experience that usually plays a protective role. Inflammatory pain is often severe and stubborn, which has a great impact on the quality of life of patients. However, there has been no breakthrough in the treatment strategy and mechanism of inflammatory pain.

METHODS

This study investigated the analgesic effect of tetrahydropalmatine (THP) in rats injected with complete Freund's adjuvant (CFA)-induced inflammatory pain. Allodynia and gait analysis of rats were used to evaluate the analgesic effect at different time points before and after operation. THP (2.5, 5, and 10 mg/kg) was administered intraperitoneally once daily for 7 days post Day 3. The expression levels of TNF-α and IL-1β in the spinal cord were measured by enzyme-linked immunosorbent assay. The activation of astrocytes and microglial cells in the spinal cord was tested by western blot before and after THP treatment. The apoptosis of glial cells was tested by flow cytometry after treatment with THP in the primary cultured glial cell model.

RESULTS

CFA treatment induced significant allodynia and caused abnormal gait in rats. Administration of THP at 10 mg/kg significantly alleviated CFA-induced inflammatory pain behaviors. Moreover, CFA-induced activation of glial cells and the increased levels of TNF-α and IL-1β were inhibited by THP administration. In addition, THP promotes apoptosis in primary cultured glial cells. This study suggests the possible clinical utility of THP in the treatment of inflammatory pain.

CONCLUSION

THP plays an analgesic role by inhibiting the activation of glial cells and promoting apoptosis.