Disentangling Associations Between Serum Muscle Biomarkers and Sarcopenia in the Presence of Pain and Inflammation Among Patients With Osteoarthritis: The SPSS-OK Study

Associations between biomarkers and skeletal muscle function in individuals with osteoarthritis: a systematic review and meta-analysis

OBJECTIVES

Skeletal muscle dysfunction is the primary cause of functional limitations in osteoarthritis, associated biomarkers have the potential as targets for early disease identification, diagnosis, and prevention of osteoarthritis disability. This review aimed to identify associations between biomarkers and lower limb skeletal muscle function in individuals with osteoarthritis.

METHODS

A systematic literature review and meta-analysis conducted in PubMed, MEDLINE, CINAHL, EMBASE, Scopus, SPORTDiscus and Web of Science databases from inception to 8th August 2023. Two independent reviewers performed the title, abstract, full-text screening, data extraction and methodological quality assessment. A meta-analysis was undertaken based on the available data.

RESULTS

Twenty-four studies with 4101 participants with osteoarthritis were included (females: 78%; age range; 49 to 71 years). One study reported muscle-specific biomarkers (n = 3), whilst six studies reported osteoarthritis-specific markers (n = 5). Overall, 93 biomarkers were reported, predominately characterised as inflammatory (n = 35), metabolic (n = 15), and hormones (n = 10). Muscle strength and vitamin D reported a significant association (Hedge's g: 0.58 (Standard Error (SE): 0.27; P = 0.03), k = 3 studies). Walking speed and high-sensitivity C-reactive protein reported no significant associations (Hedge's g: -0.02 (SE: 0.05; P = 0.73), k = 3 studies).

CONCLUSION

Associations between biomarkers and lower limb skeletal muscle function in individuals with osteoarthritis was limited, the few studies exploring lower limb muscle measures were mainly secondary outcomes. Furthermore, biomarkers were largely related to overall health, with a lack of muscle specific biomarkers. As such, the mechanistic pathways through which these associations occur are less evident, and difficult to draw clear conclusions on these relationships.

TRIAL REGISTRATION

Registered on PROSPERO (CRD42022359405).

Prognostic significance of creatine kinase in resected pancreatic cancer

BACKGROUND

Creatine kinase (CK) levels decrease with cancer progression and muscle wasting, but its association with pancreatic ductal adenocarcinoma (PDAC) remains unclear. The aim of this study was to investigate CK as a prognostic biomarker and surrogate marker for muscle mass in patients with PDAC.

METHODS

A retrospective analysis of 476 patients with PDAC was conducted. CK levels were categorized into low and high groups using receiver-operating characteristic (ROC) curve analysis.

RESULTS

Among the 476 patients, 200 (42.0%) and 276 (58.0%) were classified into the low and high CK groups, respectively. The low CK group had significantly poorer overall survival (p < .001) and recurrence-free survival (p < .001) compared to the high CK group. Multivariate analysis identified low CK as an independent poor prognostic factor (p < .001). The low CK group had significantly lower skeletal muscle index (p = .048) than the high CK group; however, the difference was slight and not significantly associated with sarcopenia. Additionally, combined risk assessment incorporating CK and resectability facilitated a more nuanced prognostic stratification.

CONCLUSIONS

CK served as a reliable prognostic marker independent from resectability but was less effective as a marker for sarcopenia in PDAC.

Comparison of creatine kinase elevation caused by Janus kinase inhibitors and interleukin-6 inhibitors in patients with rheumatoid arthritis: A propensity score-matched study

Objectives

This study aimed to examine whether creatine kinase (CK) elevation occurs with interleukin (IL)-6 inhibitors, as in Janus kinase (JAK) inhibitors, which are reported to increase CK levels in rheumatoid arthritis.

Patients and methods

A multicenter database of JAK inhibitor and IL-6 inhibitor treatment was retrospectively searched between January 2016 to December 2022; 142 cases (117 females, 25 males, mean age: 63.8±13.0 years; range, 20 to 85 years), with 71 cases in each group, were extracted by propensity score matching using age, sex, body mass index, and CK at 0 weeks. The outlier rate was compared. Patients' background characteristics related to elevated CK levels at 24 weeks were investigated by univariate and multivariate analyses.

Results

Creatine kinase levels at 4 and 12 weeks were significantly higher with JAK inhibitors than with IL-6 inhibitors (four weeks, 72 vs. 87.5 IU/mL, p=0.016; 12 weeks, 71 vs. 95.5 IU/mL, p=0.028). The outlier rate (Grade 1) with JAK inhibitors increased significantly over time (0 weeks, 4.2%; four weeks, 18.1%; 12 weeks, 21.7%; 24 weeks, 18.3%; p=0.015), whereas that with IL-6 inhibitors increased slightly (0 weeks, 5.6%; four weeks, 9.2%; 12 weeks, 8.6%; 24 weeks, 8.5%; p=0.745), with a significant difference between the groups (p=0.035). No patients discontinued treatment due to myalgia or renal dysfunction. The factors significantly positively related to elevated CK levels at 24 weeks were male sex and creatinine. Those significantly negatively related were Steinbrocker stage and class, modified health assessment questionnaire scores, estimated glomerular filtration rate, and glucocorticoid dose.

Conclusion

Mild CK elevations with JAK inhibitors are not a particular clinical problem. CK elevation might be specific to JAK inhibitors.

Inflammatory profile in patients with rheumatoid arthritis and sarcopenia

INTRODUCTION

Sarcopenia is characterized by the loss of muscle mass and strength associated with aging; however, individuals with chronic diseases are at risk at the early stages. In rheumatoid arthritis (RA), sustained chronic inflammation influences muscle deterioration. It may expedite the development of sarcopenia, which has been linked to physical disability, cardiovascular events, disease activity of RA, and premature death. We aimed to compare the inflammatory profiles of patients with RA with and without sarcopenia.

METHODS

This cross-sectional study involved 165 women with RA. Sarcopenia was diagnosed according to criteria established by the European Working Group on Sarcopenia in Older People. To assess the inflammatory profile, concentrations of cytokines such as EGF, IL-17, IL-1α, IL-1β, IL-6, TNFα, TNFβ, and creatine kinase (CK) were measured.

RESULTS

The prevalence of sarcopenia was 15.8% (95% CI: 8.9-18.2). The median age of patients with sarcopenia was 59.5 years (49.8-65.3), compared to 50 years (43-59 years) p = 0.001. The disease duration was also longer in patients with sarcopenia, 21 years (15-30), compared to those without sarcopenia, 13 years (7.3-20) p = 0.001. The inflammatory profile differed between patients with and without sarcopenia, revealing that the cytokines IL-1α, IL-6, and TNFβ concentrations were significantly higher (p < 0.05) in patients with sarcopenia, adjusted for BMI, age, and disease duration.

CONCLUSION

Patients with RA and sarcopenia were older and exhibited longer disease duration and higher levels of inflammatory cytokines compared to those without sarcopenia. These findings suggest potential implications for clinical outcomes. Key Points • The prevalence of sarcopenia in women with rheumatoid arthritis was 15.8% (95% CI, 8.9-18.2). • Levels of IL-1α, IL-6, and TNFβ cytokines were significantly higher in women with rheumatoid arthritis and sarcopenia compared with those without sarcopenia, adjusted for BMI, age, and disease duration.

Azilsartan prevents muscle loss and fast- to slow-twitch muscle fiber shift in natural ageing sarcopenic rats

Sarcopenia is a musculoskeletal disease that reduces muscle mass and strength in older individuals. The study investigates the effects of azilsartan (AZL) on skeletal muscle loss in natural sarcopenic rats. Male Sprague-Dawley rats aged 4-6 months and 18-21 months were selected as young-matched control and natural-aged (sarcopenic) rats, respectively. Rats were allocated into young and old control (YC and OC) and young and old AZL treatment (YT and OT) groups, which received vehicles and AZL (8 mg/kg, orally) for 6 weeks. Rats were then sacrificed after muscle function analysis. Serum and gastrocnemius (GN) muscles were isolated for further endpoints. AZL significantly improved muscle grip strength and antioxidant levels in sarcopenic rats. AZL also restored the levels of insulin, testosterone, and muscle biomarkers such as myostatin and creatinine kinase in sarcopenic rats. Furthermore, AZL treatment improved the cellular and ultrastructure of GN muscle and prevented the shift of type II (glycolytic) myofibers to type I (oxidative) myofibers. The results showed that AZL intervention restored protein synthesis in natural sarcopenic rats by increasing p-Akt-1 and decreasing muscle RING-finger protein-1 and tumor necrosis factor alpha immunoexpressions. In conclusion, the present findings showed that AZL could be an effective intervention in treating age-related muscle impairments.

Associations of Serum CXCL12α and CK Levels with Skeletal Muscle Mass in Older Adults

Sarcopenia, a condition characterized by gradual loss of skeletal muscle mass and function, is a complex diagnosis; the decisive criterion in this diagnosis is the measurement of appendicular skeletal muscle index (ASMI). To identify potential serum markers predictive of sarcopenia in older adults, we evaluated correlations between ASMI, clinical data, and 34 serum inflammation markers in 80 older adults. Pearson's correlation analyses confirmed that ASMI was positively correlated with nutritional status (p = 0.001) and serum creatine kinase (CK) (p = 0.019) but negatively correlated with serum CXCL12α (p = 0.023), a chemoattractant for muscle stem cells. In the case group, ASMI was negatively correlated with serum interleukin (IL)-7 (p = 0.024), a myokine expressed and secreted from skeletal muscle cells in vitro. Multivariate binary logistic regression analyses identified four risk factors for sarcopenia in our study: advanced age (p = 0.012), malnutrition (p = 0.038), low serum CK levels (p = 0.044), and high serum CXCL12α levels (p = 0.029). Low CK and high CXCL12α levels serve as combinatorial serum markers of sarcopenia in older adults. The linear correlation between ASMI and CXCL12α levels may facilitate the development of new regression models for future studies on sarcopenia.

The correlation between serum creatine kinase with low muscle mass in type 2 diabetes patients

Creatine kinase (CK), the key enzyme in regulating energy metabolism, is demonstrated to be correlated with insulin resistance. Type 2 diabetes mellitus (T2DM) is considered as a risk factor for developing low muscle mass. The purpose of this investigation was to evaluate whether serum CK is associated with low muscle mass in T2DM patients. This cross-sectional study enrolled a consecutive population of 1086 T2DM patients recruited from the inpatients in our department. Dual-energy X-ray absorptiometry was utilized to detect the skeletal muscle index (SMI). In all, 117 males (20.24%) and 72 females (16.51%) showed low muscle mass in T2DM patients. CK was associated with a reduced risk of low muscle mass in male and female T2DM patients. SMI was correlated with age, duration of diabetes, body mass index (BMI), diastolic blood pressure (DBP), triglyceride, high-density lipoprotein cholesterol, and CK in male subjects analyzed using linear regression. Linear regression analysis showed that SMI was correlated with age, BMI, DBP, and CK in female subjects. In addition, CK was correlated with BMI and fasting plasma glucose in male and female T2DM groups. CK is inversely correlated with low muscle mass in T2DM patients.

Effects of vibration training vs. conventional resistance training among community-dwelling older people with sarcopenia: three-arm randomized controlled trial protocol

Introduction

Sarcopenia is a chronic and progressive disease, which is accompanied by the decline in muscle mass, muscle strength, and physical performance with aging, and it can lead to falls, fracture, and premature death. The prevention and treatment of sarcopenia mainly include exercise therapy and nutritional supplement. Exercise therapy is one of the most potential interventions to prevent and/or delay the progression of sarcopenia. Resistance training (RT), one of the most commonly used exercise types, is widely used in the treatment of sarcopenia, while vibration training (VT) is a prospective strategy for improving sarcopenia in older people. The aim of our study is to compare the effect of VT and RT in older people with sarcopenia on muscle mass, muscle strength, physical performance, blood biomarkers, and quality of life.

Methods and analysis

Our study is a 12-week, three-arm randomized controlled trial with assessor-blinded. The diagnosis criteria for subject recruitment adopt the guidelines for the Asian Working Group for Sarcopenia. A total of 54 subjects who met the criteria were randomized into one of the following three groups: VT group, RT group, and control group. The VT group and RT group received a 12-week whole-body vibration training and a resistance training program three times every week, respectively. The primary outcome is lower limb muscle strength, and the secondary outcomes include muscle mass, upper limb muscle strength, physical performance, blood biomarkers, and quality of life. We then performed assessments three times, at baseline (0 week), after intervention (12 weeks), and follow-up (24 weeks). The adverse events were also be reported. All outcome measurements were performed by the same researchers. Data were saved in the unified database, and the collected data of all subjects were analyzed by intention-to-treat analysis.

Ethics and dissemination

This study was reviewed and approved by the Ethical Committee of Xinhua Hospital Chongming Branch. The findings of the study were authorized in peer-reviewed journals with online access; meanwhile, it will be presented at domestic or international academic congresses.

Clinical trial registration

Chinese Clinical Trial Registry (ChiCTR2100051178), registered on 15 September 2021.

Prognostic significance of preoperative low serum creatine kinase levels in gastric cancer

PURPOSE

We evaluated the clinicopathological and prognostic significance of preoperative serum creatine kinase (CK) levels in gastric cancer.

PATIENTS AND METHODS

The subjects of this retrospective study were 942 patients who underwent surgery without preoperative chemotherapy for gastric cancer (643 men and 299 women), excluding Stage IV gastric cancer, between January, 2001 and December, 2020. We set the cutoff values for CK according to gender, as 64 U/L for men and 57 U/L for women, and evaluated the clinicopathological, prognostic, and gender significance of low CK levels by multivariate analysis.

RESULTS

Tumor depth was significantly associated with low serum CK levels (p < 0.001). The low CK group showed significantly worse overall survival than the high CK group (p = 0.01). The prognostic impact of low CK levels was evident only in men (p = 0.009). In women, low CK levels were not an independent risk factor for poor prognosis (p = 0.33). These prognostic impacts of low CK levels on overall survival and recurrence-free survival were similar.

CONCLUSION

Low preoperative CK levels in men with gastric cancer were predictive of poor survival. These prognostic impacts of low CK levels were not evident in women.

Identification of Coenzyme Q10 and Skeletal Muscle Protein Biomarkers as Potential Factors to Assist in the Diagnosis of Sarcopenia

The aim of this study was to explore the use of coenzyme Q10 and skeletal muscle protein biomarkers in the diagnosis of sarcopenia. Subjects with or without sarcopenia were recruited. The anthropometric, muscle strength and endurance measurements were assessed. Muscle proteins (albumin and creatine kinase), myokines (irisin and myostatin), and the coenzyme Q10 level were measured. Approximately half of the subjects suffered from a low coenzyme Q10 concentration (<0.5 μM). The levels of creatinine kinase and irisin were significantly lower in subjects with sarcopenia (p ≤ 0.05). In receiver operating characteristic analyses, irisin and creatine kinase showed a better prediction capability for sarcopenia (area under the curve, irisin: 0.64 vs. creatinine kinase: 0.61) than other biomarkers. Additionally, a low level of irisin (<118.0 ng/mL, odds ratio, 6.46, p < 0.01), creatine kinase (<69.5 U/L, odds ratio, 3.31, p = 0.04), or coenzyme Q10 (<0.67 μM, odds ratio, 9.79, p < 0.01) may increase the risk for sarcopenia even after adjusting for confounders. Since the levels of coenzyme Q10 and muscle biomarkers, such as irisin and creatine kinase, are associated with sarcopenia, we suggest they could be used as candidate markers to assist in the diagnosis of sarcopenia.

Effects of Protein-Rich Nutritional Composition Supplementation on Sarcopenia Indices and Physical Activity during Resistance Exercise Training in Older Women with Knee Osteoarthritis

Older adults with knee osteoarthritis (KOA) are at high risk of sarcopenia. Protein-rich nutritional composition supplementation (PS) combined with resistance exercise training (RET) improves muscle gains and facilitates physical activity in older adults. However, whether PS augments the effects of RET on muscle mass and PA in patients with KOA remains unclear. Therefore, this study identified the effects of PS on sarcopenic indices and PA in older women with KOA subjected to an RET program. Eligible older women aged 60–85 years and diagnosed as having KOA were randomly assigned to either the experimental group (EG) or the control group (CG). Both groups performed RET twice a week for 12 weeks. The EG received additional PS during this period. Outcome measures included appendicular lean mass index, walking speed, physical activity, and scores on the Western Ontario and McMaster Universities Osteoarthritis Index—WOMAC). All measures were tested at baseline and after intervention. With participant characteristics and baseline scores as covariates, analysis of variance was performed to identify between-group differences in changes in all outcome measures after intervention. Statistical significance was defined as p < 0.05. Compared with the CG, the EG achieved greater changes in appendicular lean mass index (adjusted mean difference (aMD) = 0.19 kg/m², p < 0.01), physical activity (aMD = 30.0 MET-hour/week, p < 0.001), walking speed (aMD = 0.09 m/s, p < 0.05), and WOMAC global function (aMD = −8.21, p < 0.001) after intervention. In conclusion, PS exerted augmentative effects on sarcopenic indices, physical activity, and perceived global WOMAC score in older women with KOA through 12 weeks of RET.

The prevalence and risk factors of sarcopenia in rheumatoid arthritis patients: A systematic review and meta-regression analysis

BACKGROUND

Sarcopenia is an ever-increasingly recognized entity in aging or chronically-ill individuals. A recent surge of researches came out on sarcopenia in rheumatoid arthritis (RA). However, the results varied widely. We tried to assess the prevalence of and associated factors with sarcopenia in patients with RA.

METHODS

We searched the investigations dealing with the prevalence of and associated factors with sarcopenia in RA from PubMed, EMBASE, CENTRAL, EBSCOhost, Airiti Library, CEPS, CNKI and J-STAGE from the inception to January 11, 2020. Effects regarding prevalence and associated factors were extracted and evaluated by random-effects model. Sensitivity analysis was also performed.

RESULTS

Seventeen studies containing 3,140 RA subjects were identified. After exclusion of outliers, the pooled prevalence of sarcopenia was 31%. Neither ongoing-study districts nor diagnostic modalities affected prevalence significantly. Any associated factors being mentioned in at least two publications were analyzed, yielding functional limitation (Steinbrocker stage III/IV), high CRP and RF seropositivity as the significant risk factors. Based on disease durations, we carried out meta-regression and found DAS28 and HAQ are predictive models. There was no alteration in the interpretation of results from sensitivity analysis after removal of any studies skewed in sampling distribution.

CONCLUSIONS

The prevalence of sarcopenia in patients with RA is high, compared to that in general counterparts. Disease duration rather than age, residing area or diagnostic modalities influences sarcopenia development; DAS28 and HAQ predict occurrence. High index of suspicion to facilitate early detection of sarcopenia in RA patients is important.

Characterization of the plasma proteomic profile of frailty phenotype

Frailty is a risk factor for poor health outcomes in older adults. The aim of this study was to identify plasma proteomic biomarkers of frailty in 752 men and women older than 65 years of age from the InCHIANTI study. One thousand three hundred one plasma proteins were measured using an aptamer-based assay. Associations of each protein with frailty status were assessed using logistic regression and four proteins creatine kinase M-type (CKM), B-type (CKB), C-X-C motif chemokine ligand 13 (CXCL13), and thrombospondin 2 (THBS2) were associated with frailty status. Two proteins, cyclin-dependent kinase 5 (CDK5/CDK5R1) and interleukin 1 alpha (IL1A), were associated with worsening of frailty status over time in volunteers free of frailty at baseline. Using partial least squares discriminant analysis (PLS-DA), data of 1301 proteins was able to discriminate between frail and non-frail with a 2% error rate. The proteins with greater discriminatory ability represented the inflammation, blood coagulation, and cell growth pathways. The utility of these proteins as biomarkers of frailty should be further explored.

Ancestral contribution of the muscle-specific creatine kinase (CKM) polymorphism rs4884 in the knee osteoarthritis risk: a preliminary study

INTRODUCTION/OBJECTIVES

Articular cartilage and periarticular muscle tissues are strongly affected during knee osteoarthritis (OA). Creatine kinase (CK) is an enzyme expressed in several tissues, but the isoform CK-MM is specific of skeletal muscle, and its serum concentration is used as a biomarker of muscle damage. Genetic variants of the CKM gene have been associated with various pathologies, but to date, there are no reports of association with OA. Due to the rs4884 polymorphism being well represented in the Mexican population, it is used as an ancestry informative marker; thus, the goal of this preliminary report was to evaluate the association of this polymorphism in primary knee OA Mexican patients.

METHOD

Eighty-seven patients with primary knee OA were compared with 107 healthy controls. Serum CK-MM was determined using the dot blot system, and genotyping was performed using the OpenArray system. Logistic regression models were used to assess the association between the rs4884 polymorphism and OA susceptibility adjusting by gender, age, and body mass index.

RESULTS

There were no significant differences in serum CK-MM values between patients and controls. The GG genotype and the G allele had a higher frequency in the control group compared with the OA group (24.3% vs. 12.6%, OR = 0.34, 95% CI = 0.14-0.84, P = 0.019; and 40.2% vs. 28.2%, OR = 0.51, 95% CI = 0.32-0.82, P = 0.005, respectively).

CONCLUSIONS

Our results suggest a protection role of the rs4884 polymorphism against knee OA development; further studies are required to confirm it. Key Points • CK-MM enzyme catalyzes the conversion of creatine and ATP to create phosphocreatine and ADP; this reaction is reversible. • In tissues that consume ATP rapidly, such as skeletal muscle, the phosphocreatine serves as an important energy reservoir. • During knee OA, peripheral muscle tissues of the joint may be affected. • The rs4884 polymorphism of the CKM gene may participate as a protective factor in the development of OA.

Is inflammatory signaling involved in disease-related muscle wasting? Evidence from osteoarthritis, chronic obstructive pulmonary disease and type II diabetes

Muscle loss is an important feature that occurs in multiple pathologies including osteoarthritis (OA), chronic obstructive pulmonary disease (COPD) and type II diabetes (T2D). Despite differences in pathogenesis and disease-related complications, there are reasons to believe that some fundamental underlying mechanisms are inherent to the muscle wasting process, irrespective of the pathology. Recent evidence shows that inflammation, either local or systemic, contributes to the modulation of muscle mass and/or muscle strength, via an altered molecular profile in muscle tissue. However, it remains ambiguous to which extent and via which mechanisms inflammatory signaling affects muscle mass in disease. Therefore, the objective of the present review is to discuss the role of inflammation on skeletal muscle anabolism, catabolism and functionality in three pathologies that are characterized by an eventual loss in muscle mass (and muscle strength), i.e. OA, COPD and T2D. In OA and COPD, most rodent models confirmed that systemic (COPD) or muscle (OA) inflammation directly induces muscle loss or muscle dysfunctionality. However, in a patient population, the association between inflammation and muscular maladaptations are more ambiguous. For example, in T2D patients, systemic inflammation is associated with muscle loss whereas in OA patients this link has not consistently been established. T2D rodent models revealed that increased levels of advanced glycation end-products (AGEs) and a decreased mTORC1 activation play a key role in muscle atrophy, but it remains to be elucidated whether AGEs and mTORC1 are interconnected and contribute to muscle loss in T2D patients. Generally, if any, associations between inflammation and muscle are mainly based on observational and cross-sectional data. There is definitely a need for longitudinal evidence through well-powered randomized control trials that take into account confounders such as age, disease-phenotypes, comorbidities, physical (in) activity etc. This will allow to improve our understanding of the complex interaction between inflammatory signaling and muscle mass loss and hence contribute to the development of therapeutic strategies to combat muscle wasting in these diseases.