Ursodeoxycholic acid(UDCA)is a naturally occurring,low-toxicity,and hydrophilic bile acid(BA)in the human body that is converted by intestinal flora using primary BA.Solute carrier family 7 member 11(SLC7A11)functions to uptake extracellular cystine in exchange for glutamate,and is highly expressed in a variety of human cancers.Retroperitoneal liposarcoma(RLPS)refers to liposarcoma originating from the retroperitoneal area.Lipidomics analysis revealed that UDCA was one of the most significantly down-regulated metabolites in sera of RIPS patients compared with healthy subjects.The augmentation of UDCA concentration(≥25 μg/mL)demonstrated a suppressive effect on the proliferation of liposarcoma cells.[15N2]-cystine and[13Cs]-glutamine isotope tracing revealed that UDCA impairs cystine uptake and glutathione(GSH)synthesis.Mechanistically,UDCA binds to the cystine transporter SLC7A11 to inhibit cystine uptake and impair GSH de novo synthesis,leading to reactive oxygen species(ROS)accumulation and mitochondrial oxidative damage.Furthermore,UDCA can promote the anti-cancer effects of ferroptosis inducers(Erastin,RSL3),the murine double minute 2(MDM2)inhibitors(Nutlin 3a,RG7112),cyclin dependent kinase 4(CDK4)inhibitor(Abemaciclib),and glutaminase inhibitor(CB839).Together,UDCA functions as a cystine exchange factor that binds to SLC7A11 for antitumor activity,and SLC7A11 is not only a new transporter for BA but also a clinically applicable target for UDCA.More importantly,in combination with other antitumor chemotherapy or physiotherapy treatments,UDCA may provide effective and promising treatment strategies for RLPS or other types of tumors in a ROS-dependent manner.

Objective:To investigate the efficacy of oral folic acid intervention in lung cancer patients with radiation esophagitis (RE) caused by concurrent chemoradiotherapy.Methods:In this randomized, controlled, single-center clinical trial, a total of 82 patients with stage N 2-N 3 lung cancer including small cell lung cancer (SCLC) and non-small cell lung cancer (NSCLC) admitted to the Affiliated Cancer Hospital of Guizhou Medical University from June 2022 to October 2023 were prospectively included. All enrolled patients were randomly divided into the experimental group (folic acid group) and control group according to 1 vs. 1 of simple random method, and patients in both groups were required to receive radiation therapy for lung lesions and mediastinal metastatic lymph nodes [≥2 cycles of chemotherapy were completed during the same period of radiotherapy (≥40 Gy / 20 F) or targeted drugs were given simultaneously]. The severity of RE was evaluated using the modified common terminology criteria for adverse events criteria of the National Cancer Institute in both groups weekly at the onset of radiation esophagitis symptoms and thereafter until 1 week after the end of radiotherapy. Conventional treatment of RE was delivered according to the grading criteria of the Radiation Therapy Oncology Group. Patients in the folic acid group were given with folic acid tablets 30 mg/d orally at the beginning of radiotherapy until the end of radiotherapy, while those in the control group did not receive any drug intervention. The onset time, severity and duration of RE, and changes in the severity of esophageal toxicity after conventional treatment were recorded and analyzed. Serum folate value, serum vitamin B 12 value and homocysteine value were measured before and after radiotherapy. For continuous quantitative variables, independent sample t-test or independent sample rank-sum test was used for comparison among different groups. For categorical data, Chi-square test or Fisher's exact probability method was used for comparison among different groups. Results:During the observation period, no grade 4 or above RE was reported between two groups. The incidence of grade 0, 1, 2 and 3 RE in the folic acid and control groups was 10% (4/40) and 5% (2/41), 70% (28/40) and 42% (17/41), 15% (6/40) and 51% (21/41), 5% (2/40) and 2% (1/41), respectively. The differences were not statistically significant between two groups ( P=0.456). However, the incidence of grade 0-1 RE in the folic acid group was significantly higher than that in the control group ( Z=2.72, P=0.006). The median time of RE in the folic acid group and control group was 12 d (range 7-52 d) and 15 d (range 11-56 d) after the start of radiotherapy, respectively, with no statistically significant difference ( χ2=-0.75, P=0.456). However, median duration of the individual's most severe RE was 12 d (range 4-36 d) and 21 d (range 7-38 d) in the folic acid group and control groups, respectively, and the differences were statistically significant ( χ2=2.10, P=0.039). In the folic acid group, the grades of swallowing with pain and dysphagia were significantly declined after folic acid intervention, especially at 2 weeks after the occurrence of RE ( P=0.001, P=0.002). The remission rate of RE after 1 week in the folic acid group was higher than that in the control group, and the difference was statistically significant ( χ2=7.36, P=0.012). Conclusion:Oral intake of folic acid during concurrent chemoradiotherapy for lung cancer cannot reduce the incidence of RE, but it may reduce its severity, shorten the duration of the most severe RE in individuals, and have a certain protective effect.

Objective:To analyze the changes and significance in clinical cardiac indicators of early cardiac myocardial dysfunction and cardiac substructure dose during conventional radiotherapy for N 2-N 3 non-small cell lung cancer (NSCLC) with mediastinal lymph node metastases. Methods:The data of 34 NSCLC patients with lymph node metastases in regions 4-8 admitted to the Affiliated Cancer Hospital of Guizhou Medical University from June 2022 to August 2023 were observed and analyzed. All patients were treated with volumetric modulated arc therapy with a prescribed dose of 60-70 Gy. Cardiac troponin T (cTnT) and N-terminal pro-B-type natriuretic peptide (NT-proBNP) were measured at 6 time points: within 1 week before radiotherapy ( t0); when the cumulative radiotherapy dose reaches 20 Gy ( t20), 40 Gy ( t40), 60 Gy ( t60) during radiotherapy; within 1 week after radiotherapy ( tp); 1 month after radiotherapy( tp1). Left ventricular global longitudinal strain (LVGLS) and left atrial global longitudinal strain (LAGLS) were assessed at 4 time points: t0, t40, tp and tp1, respectively. The changes in cardiac indicators at different time points during radiotherapy and their correlation with substructure doses were analyzed using analysis of variance, linear regression analysis, and Pearson correlation. Results:The correlation between cardiac substructure dose and mean heart dose (MHD) in the study cohort in the descending order was as follows: left ventricle ( B=0.43, P<0.001), right ventricle ( B=0.37, P=0.002), left atrium ( B=0.16, P<0.001), and right atrium ( B=0.15, P=0.001). There were significant differences in the changes of LVGLS and LAGLS across different time points ( F=3.13, P=0.029; F=17.18, P<0.001). At 1 month after radiation, LAGLS was significantly decreased compared to pre-radiation levels ( P=0.009), whereas no significant difference was observed in LVGLS ( P=1.000). No significant differences were observed in the changes of cTnT and NT-proBNP across different time points (all P>0.05). Significant correlations were identified between cTnT and right ventricle mean dose at t40 ( r=0.38, P=0.025), as well as between NT-proBNP and right atrium mean dose at t60 and tp ( r=0.54, P=0.001; r=0.41, P=0.016). Conclusions:At present, there is no significant difference between the sensitive serum markers of myocardial injury and LVGLS in detecting early myocardial injury. LAGLS may hold substantial clinical value. There is uncertainty about radiation injury and repair of various cardiac substructures.

Ursodeoxycholic acid (UDCA) is a naturally occurring, low-toxicity, and hydrophilic bile acid (BA) in the human body that is converted by intestinal flora using primary BA. Solute carrier family 7 member 11 (SLC7A11) functions to uptake extracellular cystine in exchange for glutamate, and is highly expressed in a variety of human cancers. Retroperitoneal liposarcoma (RLPS) refers to liposarcoma originating from the retroperitoneal area. Lipidomics analysis revealed that UDCA was one of the most significantly downregulated metabolites in sera of RLPS patients compared with healthy subjects. The augmentation of UDCA concentration (≥25 μg/mL) demonstrated a suppressive effect on the proliferation of liposarcoma cells. [¹⁵N₂]-cystine and [¹³C₅]-glutamine isotope tracing revealed that UDCA impairs cystine uptake and glutathione (GSH) synthesis. Mechanistically, UDCA binds to the cystine transporter SLC7A11 to inhibit cystine uptake and impair GSH de novo synthesis, leading to reactive oxygen species (ROS) accumulation and mitochondrial oxidative damage. Furthermore, UDCA can promote the anti-cancer effects of ferroptosis inducers (Erastin, RSL3), the murine double minute 2 (MDM2) inhibitors (Nutlin 3a, RG7112), cyclin dependent kinase 4 (CDK4) inhibitor (Abemaciclib), and glutaminase inhibitor (CB839). Together, UDCA functions as a cystine exchange factor that binds to SLC7A11 for antitumor activity, and SLC7A11 is not only a new transporter for BA but also a clinically applicable target for UDCA. More importantly, in combination with other antitumor chemotherapy or physiotherapy treatments, UDCA may provide effective and promising treatment strategies for RLPS or other types of tumors in a ROS-dependent manner.

BACKGROUND:In recent years,epidemiological studies have shown that obesity is a risk factor for knee osteoarthritis,and fatty acid intake,metabolism and biosynthesis are closely related to the development of obesity.However,the causal relationship between fatty acids and osteoarthritis is still unknown.OBJECTIVE:Using the Mendelian randomization analysis to investigate the causal relationship between five fatty acid phenotypes and knee osteoarthritis.METHODS:The genome-wide association study data on fatty acid ratios from the UK Biobank(met-D)and genome-wide association study data on knee osteoarthritis from the EBI-A database were pooled together.Single nucleotide polymorphisms were used as instrumental variables and sensitive single nucleotide polymorphisms were selected for analysis.Two-sample Mendelian randomization analysis was conducted to evaluate the causal relationship between fatty acids and knee osteoarthritis outcome risk.We used inverse variance weighting method,MR-Egger regression method,weighted median method,weighted model method,and simple model method to study the causal relationship between fatty acids and knee osteoarthritis.Further inverse Mendelian randomization analysis was performed in the same way to ensure the validity of the results.RESULTS AND CONCLUSION:The forward analysis and inverse variance weighting method showed a causal relationship between three types of fatty acid phenotypes and knee osteoarthritis.Among them,the proportion of saturated fatty acids to total fatty acids was positively correlated with the risk of knee osteoarthritis(odds ratio[OR]=1.825,95%confidence interval(CI):1.230,2.706,P=0.003),the proportion of omega 3 polyunsaturated fatty acids to total fatty acids was negatively correlated with the risk of knee osteoarthritis(OR=0.822,95%CI:0.688 8,0.981,P=0.03),and the proportion of omega 6 polyunsaturated fatty acids to total fatty acids was positively correlated with the risk of knee osteoarthritis(OR=1.268,95%CI:1.079,1.491,P=0.004).There were two types of fatty acid phenotypes that do not have a causal relationship with knee osteoarthritis,including total fatty acids(OR=0.925,95%CI:0.804-1.066,P=0.283)and the proportion of monounsaturated fatty acids to total fatty acids(OR=0.877,95%CI:0.756-1.018,P=0.084).The reverse analysis results indicated that when knee osteoarthritis was used as exposure data,there was no significant causal relationship with the phenotype of fatty acids.The sensitivity analysis results showed that the P-values of the bidirectional Mendelian randomization Cochran's Q-test and MR Egger regression were both greater than 0.05,indicating that there was no significant heterogeneity or pleiotropy in the causal effect analysis between fatty acid phenotype and knee osteoarthritis.To conclude,reducing the content of saturated fatty acids and omega 6 polyunsaturated fatty acids and increasing the content of omega 3 polyunsaturated fatty acids can reduce the risk of knee osteoarthritis.This provides valuable clues for studying the biological mechanisms of knee osteoarthritis and exploring the early prevention and treatment of knee osteoarthritis,as well as providing new directions for the development of interventional drugs.

BACKGROUND:In recent years,epidemiological studies have shown that obesity is a risk factor for knee osteoarthritis,and fatty acid intake,metabolism and biosynthesis are closely related to the development of obesity.However,the causal relationship between fatty acids and osteoarthritis is still unknown.OBJECTIVE:Using the Mendelian randomization analysis to investigate the causal relationship between five fatty acid phenotypes and knee osteoarthritis.METHODS:The genome-wide association study data on fatty acid ratios from the UK Biobank(met-D)and genome-wide association study data on knee osteoarthritis from the EBI-A database were pooled together.Single nucleotide polymorphisms were used as instrumental variables and sensitive single nucleotide polymorphisms were selected for analysis.Two-sample Mendelian randomization analysis was conducted to evaluate the causal relationship between fatty acids and knee osteoarthritis outcome risk.We used inverse variance weighting method,MR-Egger regression method,weighted median method,weighted model method,and simple model method to study the causal relationship between fatty acids and knee osteoarthritis.Further inverse Mendelian randomization analysis was performed in the same way to ensure the validity of the results.RESULTS AND CONCLUSION:The forward analysis and inverse variance weighting method showed a causal relationship between three types of fatty acid phenotypes and knee osteoarthritis.Among them,the proportion of saturated fatty acids to total fatty acids was positively correlated with the risk of knee osteoarthritis(odds ratio[OR]=1.825,95%confidence interval(CI):1.230,2.706,P=0.003),the proportion of omega 3 polyunsaturated fatty acids to total fatty acids was negatively correlated with the risk of knee osteoarthritis(OR=0.822,95%CI:0.688 8,0.981,P=0.03),and the proportion of omega 6 polyunsaturated fatty acids to total fatty acids was positively correlated with the risk of knee osteoarthritis(OR=1.268,95%CI:1.079,1.491,P=0.004).There were two types of fatty acid phenotypes that do not have a causal relationship with knee osteoarthritis,including total fatty acids(OR=0.925,95%CI:0.804-1.066,P=0.283)and the proportion of monounsaturated fatty acids to total fatty acids(OR=0.877,95%CI:0.756-1.018,P=0.084).The reverse analysis results indicated that when knee osteoarthritis was used as exposure data,there was no significant causal relationship with the phenotype of fatty acids.The sensitivity analysis results showed that the P-values of the bidirectional Mendelian randomization Cochran's Q-test and MR Egger regression were both greater than 0.05,indicating that there was no significant heterogeneity or pleiotropy in the causal effect analysis between fatty acid phenotype and knee osteoarthritis.To conclude,reducing the content of saturated fatty acids and omega 6 polyunsaturated fatty acids and increasing the content of omega 3 polyunsaturated fatty acids can reduce the risk of knee osteoarthritis.This provides valuable clues for studying the biological mechanisms of knee osteoarthritis and exploring the early prevention and treatment of knee osteoarthritis,as well as providing new directions for the development of interventional drugs.

Objective:To investigate the efficacy of oral folic acid intervention in lung cancer patients with radiation esophagitis (RE) caused by concurrent chemoradiotherapy.Methods:In this randomized, controlled, single-center clinical trial, a total of 82 patients with stage N 2-N 3 lung cancer including small cell lung cancer (SCLC) and non-small cell lung cancer (NSCLC) admitted to the Affiliated Cancer Hospital of Guizhou Medical University from June 2022 to October 2023 were prospectively included. All enrolled patients were randomly divided into the experimental group (folic acid group) and control group according to 1 vs. 1 of simple random method, and patients in both groups were required to receive radiation therapy for lung lesions and mediastinal metastatic lymph nodes [≥2 cycles of chemotherapy were completed during the same period of radiotherapy (≥40 Gy / 20 F) or targeted drugs were given simultaneously]. The severity of RE was evaluated using the modified common terminology criteria for adverse events criteria of the National Cancer Institute in both groups weekly at the onset of radiation esophagitis symptoms and thereafter until 1 week after the end of radiotherapy. Conventional treatment of RE was delivered according to the grading criteria of the Radiation Therapy Oncology Group. Patients in the folic acid group were given with folic acid tablets 30 mg/d orally at the beginning of radiotherapy until the end of radiotherapy, while those in the control group did not receive any drug intervention. The onset time, severity and duration of RE, and changes in the severity of esophageal toxicity after conventional treatment were recorded and analyzed. Serum folate value, serum vitamin B 12 value and homocysteine value were measured before and after radiotherapy. For continuous quantitative variables, independent sample t-test or independent sample rank-sum test was used for comparison among different groups. For categorical data, Chi-square test or Fisher's exact probability method was used for comparison among different groups. Results:During the observation period, no grade 4 or above RE was reported between two groups. The incidence of grade 0, 1, 2 and 3 RE in the folic acid and control groups was 10% (4/40) and 5% (2/41), 70% (28/40) and 42% (17/41), 15% (6/40) and 51% (21/41), 5% (2/40) and 2% (1/41), respectively. The differences were not statistically significant between two groups ( P=0.456). However, the incidence of grade 0-1 RE in the folic acid group was significantly higher than that in the control group ( Z=2.72, P=0.006). The median time of RE in the folic acid group and control group was 12 d (range 7-52 d) and 15 d (range 11-56 d) after the start of radiotherapy, respectively, with no statistically significant difference ( χ2=-0.75, P=0.456). However, median duration of the individual's most severe RE was 12 d (range 4-36 d) and 21 d (range 7-38 d) in the folic acid group and control groups, respectively, and the differences were statistically significant ( χ2=2.10, P=0.039). In the folic acid group, the grades of swallowing with pain and dysphagia were significantly declined after folic acid intervention, especially at 2 weeks after the occurrence of RE ( P=0.001, P=0.002). The remission rate of RE after 1 week in the folic acid group was higher than that in the control group, and the difference was statistically significant ( χ2=7.36, P=0.012). Conclusion:Oral intake of folic acid during concurrent chemoradiotherapy for lung cancer cannot reduce the incidence of RE, but it may reduce its severity, shorten the duration of the most severe RE in individuals, and have a certain protective effect.

Objective:To analyze the changes and significance in clinical cardiac indicators of early cardiac myocardial dysfunction and cardiac substructure dose during conventional radiotherapy for N 2-N 3 non-small cell lung cancer (NSCLC) with mediastinal lymph node metastases. Methods:The data of 34 NSCLC patients with lymph node metastases in regions 4-8 admitted to the Affiliated Cancer Hospital of Guizhou Medical University from June 2022 to August 2023 were observed and analyzed. All patients were treated with volumetric modulated arc therapy with a prescribed dose of 60-70 Gy. Cardiac troponin T (cTnT) and N-terminal pro-B-type natriuretic peptide (NT-proBNP) were measured at 6 time points: within 1 week before radiotherapy ( t0); when the cumulative radiotherapy dose reaches 20 Gy ( t20), 40 Gy ( t40), 60 Gy ( t60) during radiotherapy; within 1 week after radiotherapy ( tp); 1 month after radiotherapy( tp1). Left ventricular global longitudinal strain (LVGLS) and left atrial global longitudinal strain (LAGLS) were assessed at 4 time points: t0, t40, tp and tp1, respectively. The changes in cardiac indicators at different time points during radiotherapy and their correlation with substructure doses were analyzed using analysis of variance, linear regression analysis, and Pearson correlation. Results:The correlation between cardiac substructure dose and mean heart dose (MHD) in the study cohort in the descending order was as follows: left ventricle ( B=0.43, P<0.001), right ventricle ( B=0.37, P=0.002), left atrium ( B=0.16, P<0.001), and right atrium ( B=0.15, P=0.001). There were significant differences in the changes of LVGLS and LAGLS across different time points ( F=3.13, P=0.029; F=17.18, P<0.001). At 1 month after radiation, LAGLS was significantly decreased compared to pre-radiation levels ( P=0.009), whereas no significant difference was observed in LVGLS ( P=1.000). No significant differences were observed in the changes of cTnT and NT-proBNP across different time points (all P>0.05). Significant correlations were identified between cTnT and right ventricle mean dose at t40 ( r=0.38, P=0.025), as well as between NT-proBNP and right atrium mean dose at t60 and tp ( r=0.54, P=0.001; r=0.41, P=0.016). Conclusions:At present, there is no significant difference between the sensitive serum markers of myocardial injury and LVGLS in detecting early myocardial injury. LAGLS may hold substantial clinical value. There is uncertainty about radiation injury and repair of various cardiac substructures.

Objective:To analyze the clinical characteristics of long-term survival patients with advanced non-small cell lung cancer (NSCLC) treated with chemotherapy combined with primary tumor radiotherapy, and to establish a Nomogram prognostic model, aiming to provide a certain reference for making a decision about the treatment of advanced NSCLC.Methods:A retrospective analysis was made on the data of 260 NSCLC patients who participated in two prospective clinical studies from January 2003 to May 2012 and the data of 138 NSCLC patients admitted to the Affiliated Cancer Hospital of Guizhou Medical University from January 2014 to August 2020. The former 260 cases were used as a training set and the latter 138 cases were used as the validation set. The overall survival (OS) of ≥ 18 months was defined as long-term survival (LTS). The clinical characteristics of LTS patients were compared with those with OS less than 18 months. The clinical characteristics and treatment-related parameters between the two types of patients were compared using the χ2 test. A multivariate analysis was made using logistic regression, and a nomogram model was built using RStudio. Results:The median OS of the training set was 13.4 months (95% CI: 11.9-14.9), with 1-, 2-, and 3-year OS rates of 55.4%, 19.1%, and 11.9%, respectively. In the training set, 87 cases had LTS and were classified as the LTS group, while 173 cases had OS less than 18 months and were classified as the non-LTS group. The univariate analysis showed that the prognostic factors affecting LST included the KPS score, T status, the number of metastatic organs, the number of metastatic lesions, brain metastasis, bone metastasis, the number of chemotherapy cycles, the biologically effective dose (BED) to the primary tumor, hemoglobin level, platelet count, plasma D-dimer, fibrinogen level, lactate dehydrogenase, and lung immune prognostic index (LIPI; χ2=4.72-12.63, P < 0.05). The multivariable analysis showed that the independent prognostic factors of LTS included a number of chemotherapy cycles ≥ 4, BED ≥ 70 Gy, platelets ≤ 220×10 9/L, D-dimer ≤ 0.5 mg/L, and a good LIPI score ( P= 0.002, 0.036, 0.005, 0.008, and 0.002). A nomogram model was established using the meaningful parameters obtained in the multivariable analysis, determining that the training and validation sets had a consistency index (C-index) of 0.750 and 0.727, respectively. As shown by the analytical result of the corrected curves, for the advanced NSCLC patients treated with thoracic radiotherapy, their LTS probability predicted using the nomogram prognostic model was highly consistent with their actual LTS probability. Both the analytical result of the receiver operating characteristic (ROC) curves and the decision curve analysis (DCA) result showed that the composite prediction model was more beneficial than a single prediction model. Conclusions:For patients with advanced NSCLC treated with thoracic radiotherapy, the independent prognostic factors of LTS included the number of chemotherapy cycles, BED, platelet count, pre-chemotherapy D-dimer, and LIPI score. The Nomogram prognostic model built based on these prognostic factors is a convenient, intuitive, and personalized prediction model used to screen patients who can benefit from thoracic radiotherapy.

ObjectiveTo test the inter-tester reliability and test-retest reliability of MyotonPRO for evaluating neck and shoulder muscle performance parameters in patients with unilateral chronic neck pain, observe the difference of muscle performance between the healthy and affected sides of patients with chronic neck pain, and analyze the factors that cause the imbalance of muscle performance in patients with chronic neck pain. MethodsFrom January to June, 2023, 32 patients with unilateral chronic neck pain in Guangdong Second Traditional Chinese Medicine Hospital were selected. Two testers used the same MyotonPRO equipment to measure the muscle tone, muscle hardness and muscle elasticity on both sides of the sternocleidomastoid muscle and the upper trapezius muscle in the relaxed position. Tester 1 repeated the measurement after an interval of 30 minutes, and Tester 2 was measured within the time interval between the two measurements of Tester 1. The intraclass correlation coefficient (ICC), standard error of mean (SEM) and minimum detectable change (MDC) were calculated simultaneously. The measurement results were plotted into Bland-Altman diagram and systematic bias analysis was performed. The difference in muscle characteristics between the affected side and the healthy side was compared. At the same time, the Visual Analogue Scale (VAS) score and body mass index (BMI) of the subjects were collected for correlation analysis. ResultsExcept the sternocleidomastoid muscle elasticity of the affected side (ICC = 0.697), the inter-tester reliability of all other parameters was high to very high (ICC = 0.719 to 0.952, SEM = 0.04 to 6.53, MDC = 0.12 to 18.11). The test-retest reliability of all parameters was high (ICC = 0.883 to 0.981, SEM = 0.03 to 5.72, MDC = 0.09 to 15.84). Bland-Altman plot analysis showed that the scatter distribution was consistent. The muscle tone, muscle hardness and muscle elasticity of sternocleidomastoid muscle and upper trapezius muscle were higher on the affected side than on the healthy side (t > 2.846, P < 0.05). The asymmetry index of tension, hardness and elasticity of upper trapezius muscle and sternocleidomastoid muscle was significantly positively correlated with VAS score and BMI (r > 0.385, P < 0.05). ConclusionMyotonPRO has good inter-tester reliability and retest reliability in evaluating the muscle performance of both sides of patients with chronic neck pain. The muscle tone, muscle hardness and muscle elasticity of sternocleidomastoid muscle and upper trapezius muscle on the affected side were higher than on the healthy side, and the difference of muscle performance was positively correlated with pain and BMI.