Decreased serum biochemical markers of muscle origin in patients with ankylosing spondylitis

Comparison of shoulder muscle strength, shoulder range of motion and scapular motion in men with ankylosing spondylitis and healthy men: a case-controlled study

Background/Aims

Ankylosing spondylitis mainly affects the vertebral column, meaning that the assessment of the physical function of the upper extremity and scapulothoracic region in ankylosing spondylitis is often overlooked. Therefore, the aim of this study was to investigate shoulder muscle strength, shoulder active range of motion and three-dimensional scapular motion in patients with ankylosing spondylitis.

Methods

The study included 18 men with ankylosing spondylitis, and 16 age-matched typically healthy men as the control group. Muscle strength, active range of motion, and three-dimensional scapular motion were assessed with a digital hand-held dynamometer, an inclinometer, and an electromagnetic tracking device respectively.

Results

A decrease in shoulder flexion and abduction muscle strength on both the dominant side (P<0.001, P=0.001) and non-dominant side (P<0.001, P<0.001) was found in the ankylosing spondylitis group compared to the control group. A decrease in shoulder flexion, abduction, and external and internal rotation active range of motion on both the dominant side (P=0.001, P<0.001, P=0.015, P<0.001, respectively) and non-dominant side (P=0.001, P<0.001, P=0.017, P<0.001 respectively) was observed in the ankylosing spondylitis group. There was an increase in the upward rotation of the scapula on the non-dominant side at 30, 60, and 90° humeral elevations in the ankylosing spondylitis group compared to the control group (P=0.018, P=0.003, P=0.001 respectively). The other parameters of the scapular motion did not differ between groups (P>0.05).

Conclusions

This study showed that shoulder muscle strength and active range of motion were lower, and the upward rotation of the scapula was greater in men with ankylosing spondylitis compared to typically healthy men. The kinetics and kinematics parameters of the shoulder and scapula should be considered when assessing the physical function of patients with ankylosing spondylitis.

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

BACKGROUND/OBJECTIVE

Reduction of muscle markers, such as creatine phosphokinase (CK), in rheumatic diseases and its association with reduced muscle mass may be of clinical importance in osteoarthritis (OA). Considering the complexity of secondary sarcopenia, clarifying the association between muscle markers and sarcopenia and disentangling the involvement of OA-related conditions are of clinical importance. We investigated the association between serum muscle biomarkers and sarcopenia among patients with OA, considering the presence of pain and inflammation.

METHODS

Overall, 1425 patients with knee and hip OA scheduled for joint replacement surgery were included in a single-center cross-sectional study from Screening for People Suffering Sarcopenia in Orthopedic cohort of Kobe study. Primary outcome was sarcopenia defined by 2 criteria (the Asian Working Group for Sarcopenia and the European Working Group on Sarcopenia in Older People). Pain and inflammation were measured using the numeric rating scale and serum C-reactive protein (CRP) levels, respectively. Associations between the biomarkers (serum CK, aspartate aminotransferase, alanine aminotransferase) and sarcopenia were examined using logistic regression models.

RESULTS

Sarcopenia by the Asian Working Group for Sarcopenia criteria was present in 4.0% of patients. In adjusted analyses, sarcopenia was negatively associated with higher serum CK levels, but not with serum aspartate aminotransferase or alanine aminotransferase levels independent of pain score and serum CRP. Neither pain score nor serum CRP level was associated with sarcopenia. Similar results were found when the European Working Group on Sarcopenia in Older People criteria were used.

CONCLUSIONS

Serum CK was associated with sarcopenia, suggesting the potential usefulness for sarcopenia detection regardless of pain or inflammation in OA.

Muscle Evaluation in Axial Spondyloarthritis-The Evidence for Sarcopenia

Sarcopenia is a syndrome defined as a progressive and generalized skeletal muscle disorder associated with an increased likelihood of adverse outcomes such as falls, fractures, physical disability, and death. The actual definition of sarcopenia is based on a reduction in the values of three parameters: strength, muscle mass quantity or quality, and physical performance (the determinant of severity). Muscle wasting is a common feature in several chronic diseases, such as spondyloarthritis (SpA), and significantly increases patient morbidity and mortality. Although there has been huge progress in this field over recent years, the absence of a clear definition and clear diagnostic criteria of sarcopenia has resulted in inconsistent information regarding muscle-involvement in SpA. Thus, the aim of this review is to collect relevant evidence on muscular changes occurring during the disease process from the published literature, according to the recommended tools for sarcopenia evaluation proposed by the European Working Group on Sarcopenia in Older People 2 (EWGSOP2). In addition, data from histological, electromyography, and biochemical muscle analyses of SpA patients are also reviewed. Overall, a reduction in muscle strength with a systemic decrease in lean mass seems to be associated with a gait speed compromise. This information is usually fragmented, with no studies considering the three parameters together. This paper represents a call-to-action for the design of new studies in the future.

Factors influencing longitudinal changes of circulating liver enzyme concentrations in subjects randomized to placebo in four clinical trials

Liver enzyme concentrations are measured as safety end points in clinical trials to detect drug-related hepatotoxicity, but little is known about the epidemiology of these biomarkers in subjects without hepatic dysfunction who are enrolled in drug trials. We studied alanine and aspartate aminotransferase (ALT and AST) in subjects randomized to placebo who completed assessments over 36 mo in a cardiovascular outcome trial [the Stabilisation of Atherosclerotic Plaque by Initiation of Darapladib Therapy ("STABILITY") trial; n = 4,264; mean age: 64.2 yr] or over 12 mo in three trials that enrolled only subjects with type 2 diabetes (T2D) [the DIA trials; n = 308; mean age: 62.4 yr] to investigate time-dependent relationships and the factors that might affect ALT and AST, including body mass index (BMI), T2D, and renal function. Multivariate linear mixed models examined time-dependent relationships between liver enzyme concentrations as response variables and BMI, baseline T2D status, hemoglobin A_1c levels, and renal function, as explanatory variables. At baseline, ALT was higher in individuals who were men, <65 yr old, and obese and who had glomerular filtration rate (GFR) >60 ml·min^-1·1.73 m^-2. ALT was not significantly associated with T2D at baseline, although it was positively associated with HbA_1c. GFR had a greater impact on ALT than T2D. ALT concentrations decreased over time in subjects who lost weight but remained stable in individuals with increasing BMI. Weight change did not alter AST concentrations. We provide new insights on the influence of time, GFR, and HbA_1c on ALT and AST concentrations and confirm the effect of sex, age, T2D, BMI, and BMI change in subjects receiving placebo in clinical trials. NEW & NOTEWORTHY Clinical trials provide high-quality data on liver enzyme concentrations from subjects randomized to placebo that can be used to investigate the epidemiology of these biomarkers. The adjusted models show the influence of sex, age, time, renal function, type 2 diabetes, HbA_1c, and body mass index on alanine aminotransferase and aspartate aminotransferase concentrations and their relative importance. These factors need to be considered when assessing potential signals of hepatotoxicity in trials of new drugs and in clinical trials investigating subjects with nonalcoholic fatty liver disease.

Reduced Appendicular Lean Body Mass, Muscle Strength, and Size of Type II Muscle Fibers in Patients with Spondyloarthritis versus Healthy Controls: A Cross-Sectional Study

Introduction. The purpose of this study was to investigate body composition, muscle function, and muscle morphology in patients with spondyloarthritis (SpA). Methods. Ten male SpA patients (mean ± SD age 39 ± 4.1 years) were compared with ten healthy controls matched for sex, age, body mass index, and self-reported level of physical exercise. Body composition was measured by dual energy X-ray absorptiometry. Musculus quadriceps femoris (QF) strength was assessed by maximal isometric contractions prior to test of muscular endurance. Magnetic resonance imaging of QF was used to measure muscle size and calculate specific muscle strength. Percutaneous needle biopsy samples were taken from m. vastus lateralis. Results. SpA patients presented with significantly lower appendicular lean body mass (LBM) (p = 0.02), but there was no difference in bone mineral density, fat mass, or total LBM. Absolute QF strength was significantly lower in SpA patients (p = 0.03) with a parallel trend for specific strength (p = 0.08). Biopsy samples from the SpA patients revealed significantly smaller cross-sectional area (CSA) of type II muscle fibers (p = 0.04), but no difference in CSA type I fibers. Conclusions. Results indicate that the presence of SpA disease is associated with reduced appendicular LBM, muscle strength, and type II fiber CSA.

Intermediate Syndrome Following Acute Organophosphate Poisoning: Correlation with Initial Serum Levels of Muscle Enzymes

Following acute organophosphate poisoning, intermediate syndrome essentially relates to the impairment of neuromuscular transmission due to prolonged inhibition of acetylcholinesterase activity at the muscle end-plate. However, the role of muscle injury in the development of intermedicate syndrome is not clear. The aim of this study was to determine whether the initial serum levels of the muscle enzymes can predict the subsequent development of intermediate syndrome. We reviewed the files of 47 adult patients with organophosphate poisoning between April 2003 and February 2006. The muscle enzymes were obtained within first 24 hr from each patient. Among the patients, 17% (n = 8) had severe poisoning and 83% (n = 39) mild poisoning. In 10 patients (21%), intermediate syndrome was observed. Of the patients with severe poisoning, 63% (n = 5) developed subsequent intermediate syndrome; among those with mild poisoning, 13% (n = 5) developed intermediate syndrome. There was no significant difference in initial serum levels of creatine kinase and aspartate aminotransferase between the patients with severe poisoning and mild poisoning, and there was no difference in initial serum levels of creatine kinase and aspartate aminotransferase between the patients with and without intermediate syndrome. The serum levels of the muscle enzymes measured within the first 24 hr may not predict the subsequent development of intermediate syndrome.

Preliminary evidence for cachexia in patients with well-established ankylosing spondylitis

OBJECTIVES

Cachexia, defined as an accelerated loss of skeletal muscle in the context of a chronic inflammatory response, is common in rheumatoid arthritis but it has not been demonstrated in patients with ankylosing spondylitis (AS). The aim of this study was to determine muscle wasting and its functional consequences in a group of patients with well-established AS.

METHODS

Nineteen male patients (mean age 53 yrs) with long-standing AS (mean disease duration 19 yrs) and radiological changes (84% had one or more syndesmophytes) were compared with 19 age-matched healthy males with similar levels of habitual physical activity. Body composition was assessed by dual energy X-ray absorptiometry. Muscle strength was measured by isokinetic knee extension and hand grip dynamometry, and by 30 s arm curl and chair sit-to-stand tests.

RESULTS

AS patients showed a statistically and clinically significant 12% reduction in arms and legs lean mass, a proxy measure of total body skeletal muscle mass, compared with healthy controls (P < 0.05). This muscle loss was significantly associated with reduced upper and lower body strength (correlation coefficients ranging between 0.37 and 0.79, P < 0.05).

CONCLUSION

These results provide preliminary evidence that cachexia is a functionally relevant systemic complication of AS, particularly in patients with long-standing disease and radiological changes. Progressive resistance training and other interventions aimed at stimulating skeletal muscle growth might be beneficial in this population, and further studies on the pathophysiology of cachexia in AS patients are needed.

Gonadal and adrenal sex steroids in ankylosing spondylitis

A role for sex steroids in the pathogenesis of AS is suggested by the male predominance, the peak age of onset in young adults, the increased number of first manifestations and flares after pregnancy, and the fact that sex steroids may modulate immune functions. There is a theoretic possibility that (normal levels of) androgens are indeed relevant in the male sex skew of AS. It has been reported that men with AS have higher than normal androgen levels; however, the evidence that serum testosterone levels are elevated in patients with AS is not robust. Elevated DHEAS and 17 alpha-hydroxyprogesterone levels have been reported in male AS patients; these may be secondary to inflammation and stress but may theoretically also be causally related to AS. These elevations might result from a partial late onset 11 beta- or 21-hydroxylase deficiency. Current data on sex steroid hormones provide no straightforward explanation for the male predominance in AS. It is fair to say that present data in patients with long-standing AS are too limited to suggest a role for androgens in the perpetuation of the disease, but a role in the initiation and the early stages of AS cannot be excluded. Such information can only be obtained from prospective studies. Cross-sectional studies cannot clearly distinguish causal relation from secondary disease effects, because blood sampling to test these hypotheses only takes place many years after the onset of disease. The impact of sex steroids on these features of AS is still unresolved. There is as yet no rationale for the use of medication that modifies sex steroid hormones in the management of AS. Alternative explanations for the higher male prevalence of AS may be found in the different chromosomal configuration and body composition of men and women.