Muscle analysis using pQCT, DXA and MRI

Relationship between paraspinal muscle properties and bone mineral density based on QCT in patients with lumbar disc herniation

OBJECTIVE

Increasing research suggests that paraspinal muscle fat infiltration may be a potential biological marker for the assessment of osteoporosis. Our aim was to investigate the relationship between lumbar paraspinal muscle properties on MRI and volumetric bone mineral density (vBMD) based on QCT in patients with lumbar disc herniation (LDH).

METHODS

A total of 383 patients (aged 24-76 years, 193 females) with clinically and radiologically diagnosed LDH were enrolled in this retrospective study. The muscle cross-sectional area (CSA) and the proton density fat fraction (PDFF) were measured for the multifidus (MF), erector spinae (ES) and psoas major (PS) at the central level of L3/4, L4/5 and L5/S1 on lumbar MRI. QCT was used to measure the vBMD of two vertebral bodies at L1 and L2 levels. Patients were divided into three groups based on their vBMD values: normal bone density group (> 120 mg/cm3), osteopenia group (80 to 120 mg/cm3) and osteoporosis group (< 80 mg/cm3). The differences in paraspinal muscle properties among three vBMD groups were tested by one-way ANOVA with post hoc analysis. The relationships between paraspinal muscle properties and vBMD were analyzed using Pearson correlation coefficients. Furthermore, the association between vBMD and paraspinal muscle properties was further evaluated using multiple linear regression analysis, with age and sex also included as predictors.

RESULTS

Among the 383 LDH patients, 191 had normal bone density, 129 had osteopenia and 63 had osteoporosis. In LDH patients, compared to normal and osteopenia group, paraspinal muscle PDFF was significantly greater in osteoporosis group, while paraspinal muscle CSA was lower (p < 0.001). After adjusting for age and sex, it was found that MF PDFF and PS CSA were found to be independent factors influencing vBMD (p < 0.05).

CONCLUSION

In patients with LDH, paraspinal muscle properties measured by IDEAL-IQ sequence and lumbar MR scan were found to be related to vBMD. There was a correlation between the degree of paraspinal muscle PDFF and decreasing vBMD, as well as a decrease paraspinal muscle CSA with decreasing vBMD. These findings suggest that clinical management should consider offering tailored treatment options for patients with LDH based on these associations.

MRI quantitative muscle characterization in children with X-linked hypophosphatemia

INTRODUCTION

Children with X Linked Hypophosphatemia (XLH) suffer from carential ricket, bone deformities and lameness. No previous study demonstrated a morphological distinction in muscles in these patients. The aim of this prospective study was to characterize, using Magnetic Resonance Imaging (MRI), the muscle morphology of pelvis, thigh and leg in children with XLH and to compare it with typically developed (TD) children.

HYPOTHESIS

We hypothesized that lower limbs muscles in children with XLH are different from TD children and could explain limp walking.

MATERIAL AND METHODS

Three-dimensional reconstructions of the muscles were performed in 11 patients with XLH and 15 TD children. Muscle lengths, sections and volumes were calculated and normalized with height and weight. Mean age was 10.

RESULTS

Lengths were all smaller in children with XLH except for the Medius/minimus gluteus muscles (p=0.64). The difference seemed higher in muscles with a long tendinous part as semitendinosus (0.139 vs 0,164; p<0.01). All volumes were significantly inferior in children with XLH. This preliminary study showed significant differences in muscle structures between patients with XLH and TD children.

DISCUSSION

Medius/minimus gluteus seemed to be particularly developed in children with XLH. Nevertheless it is not possible to conclude if it is related to XLH or a consequence of bone deformities.

LEVEL OF PROOF

IV.

Comparisons between dual-energy X-ray absorptiometry and bioimpedance devices for appendicular lean mass and muscle quality in Hispanic adults

The purpose of this study was to compare single- and multi-frequency bioimpedance (BIA) devices against dual-energy X-ray absorptiometry (DXA) for appendicular lean mass (ALM) and muscle quality index (MQI) metrics in Hispanic adults. One hundred thirty-one Hispanic adults (18-55 years) participated in this study. ALM was measured with single-frequency bioimpedance analysis (SFBIA), multi-frequency bioimpedance analysis (MFBIA) and DXA. ALMTOTAL (left arm + right arm + left leg + right leg) and ALMARMS (left arm + right arm) were computed for all three devices. Handgrip strength (HGS) was measured using a dynamometer. The average HGS was used for all MQI models (highest left hand + highest right hand)/2. MQIARMS was defined as the ratio between HGS and ALMARMS. MQITOTAL was established as the ratio between HGS and ALMTOTAL. SFBIA and MFBIA had strong correlations with DXA for all ALM and MQI metrics (Lin's concordance correlation coefficient values ranged from 0·86 (MQIMFBIA-ARMS) to 0·97 (Arms LMSFBIA); all P < 0·001). Equivalence testing varied between methods (e.g. SFBIA v. DXA) when examining the different metrics (i.e. ALMTOTAL, ALMARMS, MQITOTAL and MQIARMS). MQIARMS was the only metric that did not differ from the line of identity and had no proportional bias when comparing all the devices against each other. The current study findings demonstrate good overall agreement between SFBIA, MFBIA and DXA for ALMTOTAL and ALMARMS in a Hispanic population. However, SFBIA and MFBIA have better agreement with DXA when used to compute MQIARMS than MQITOTAL.

Sarcopenia in peripheral arterial disease: Establishing and validating a predictive nomogram based on clinical and computed tomography angiography indicators

Purpose

To establish, validate, and clinically evaluate a nomogram for predicting the risk of sarcopenia in patients with peripheral arterial disease (PAD) based on clinical and lower extremity computed tomography angiography (LE-CTA) imaging characteristics.

Methods

Clinical data and CTA imaging features from 281 PAD patients treated between January 1, 2019, and May 1, 2023, at two hospitals were retrospectively analyzed using binary logistic regression to identify the independent risk factors for sarcopenia. These identified risk factors were used to develop a predictive nomogram. The nomogram's effectiveness was assessed through various metrics, including the receiver operating characteristic (ROC) curve, area under the curve (AUC), concordance index (C-index), Hosmer-Lemeshow (HL) test, and calibration curve. Its clinical utility was demonstrated using decision curve analysis (DCA).

Results

Several key independent risk factors for sarcopenia in PAD patients were identified, namely age, body mass index (BMI), history of coronary heart disease (CHD), and white blood cell (WBC) count, as well as the severity of luminal stenosis (P < 0.05). The discriminative ability of the nomogram was supported by the C-index and an AUC of 0.810 (95% confidence interval: 0.757-0.862). A robust concordance between predicted and observed outcomes was reflected by the calibration curve. The HL test further affirmed the model's calibration with a P-value of 0.40. The DCA curve validated the nomogram's favorable clinical utility. Lastly, the model underwent internal validation.

Conclusions

A simple nomogram based on five independent factors, namely age, BMI, history of CHD, WBC count, and the severity of luminal stenosis, was developed to assist clinicians in estimating sarcopenia risk among PAD patients. This tool boasts impressive predictive capabilities and broad utility, significantly aiding clinicians in identifying high-risk individuals and enhancing the prognosis of PAD patients.

Running Event, Age, and Competitive Level as Predictors of Dual-Energy X-Ray Absorptiometry-Derived Body Composition and Bone Health Markers in Female Runners

ABSTRACT

Wilson, LJ and Curtis, C. Running event, age, and competitive level as predictors of dual-energy x-ray absorptiometry-derived body composition and bone health markers in female runners. J Strength Cond Res XX(X): 000-000, 2024-The aim of this study was to assess the impact of running discipline, competitive level (COMP), and age on body composition measures in female athletes. A total of n = 51 female runners (age: 30.9 ± 5.7 years, stature: 166.7 ± 5.7 cm, and body mass (BM): 57.1 ± 8.2 kg) completed a full-body dual-energy x-ray absorptiometry (DXA) scan in a cross-sectional design. One-way ANOVA or Kruskal-Wallis was used to identify differences in DXA measures and independent variables. Stepwise regression determined the contribution of independent variables on DXA measures. Body fat percentage (BF%) and fat mass (FM) differed based on COMP (BF%: H(2) = 17.451; FM: H(2) = 17.406, both p ≤ 0.0001). Competitive level modestly predicted BF% and FM (BF%: R2adj = 0.316, F(1,50) = 22.660; FM: R2adj = 0.300, F(1,50) = 21.029, both p ≤ 0.0001). Bone mineral density (BMD) and BMD Z-score (BMDZ) did not differ between age, running discipline, or COMP (age: BMD: F(2,50) = 2.825, BMDZ: F(2,50) = 2.215; running discipline: BMD: F(3,50) = 1.145, BMDZ: F(3,50) = 1.474; COMP: BMD: F(2,50) = 0.074, BMDZ: F(2,50) = 1.297, all p ≤ 0.05). Age and running discipline modestly predicted BMD and BMDZ (BMD: R2adj = 0.179, F(1,50) = 5.264; BMDZ: R2adj = 0.173, F(1,50) = 4.545, both p ≤ 0.05). These findings indicate COMP may be a predictor of BF% and FM. Age and running discipline appear predictors of bone health markers. Such findings may enable medical and sport science practitioners to tailor interventions relating to realization of training adaptations, performance, and health.

Fat infiltration in skeletal muscle: Influential triggers and regulatory mechanism

Fat infiltration in skeletal muscle (also known as myosteatosis) is now recognized as a distinct disease from sarcopenia and is directly related to declining muscle capacity. Hence, understanding the origins and regulatory mechanisms of fat infiltration is vital for maintaining skeletal muscle development and improving human health. In this article, we summarized the triggering factors such as aging, metabolic diseases and metabolic syndromes, nonmetabolic diseases, and muscle injury that all induce fat infiltration in skeletal muscle. We discussed recent advances on the cellular origins of fat infiltration and found several cell types including myogenic cells and non-myogenic cells that contribute to myosteatosis. Furthermore, we reviewed the molecular regulatory mechanism, detection methods, and intervention strategies of fat infiltration in skeletal muscle. Based on the current findings, our review will provide new insight into regulating function and lipid metabolism of skeletal muscle and treating muscle-related diseases.

Sarcopenia and poor nutritional status in older adults

BACKGROUND & AIMS

The association between sarcopenia and malnutrition has been poorly studied in the older population. The purpose of this study is to address the association between sarcopenia, according to different validated definitions, and nutritional status in a large population of community-dwelling older adults.

METHODS

Observational, cross-sectional study of the Geriatric Frailty Clinic (GFC) for Assessment of Frailty and Prevention of Disability, held by the "Gérontopôle" of the Toulouse University Hospital. Patients aged above 65 years who benefitted from a Dual X-ray Densitometry (DXA) during their assessment at the GFC from June 5th 2013 to January 28th 2020 were included. Sarcopenia was defined according to proposed validated definitions. The Mini Nutritional Assessment (MNA) was used to stratify nutritional status, and identify patients with a poor nutritional status (at risk of malnutrition or malnourished, MNA <24). Multiple logistic regression analyses were performed between MNA and each sarcopenia definition adjusted for confounders.

RESULTS

Among the 938 patients with DXA data, a total of 809 (86.2 %) subjects were included in the analysis (mean age 81.8 ± 6.9 years, 527 females (65.1 %)). Prevalence of sarcopenia ranged from 12.6 % to 44.9 %, according to various definitions. Overall 244 (30.2 %) of the patients had a poor nutritional status (MNA-score <24), Baumgartner and Newman definitions of sarcopenia were both associated with low MNA-scores (OR = 4.69, CI 3.15-6.98 and OR = 2.30, CI 1.55-3.14, respectively), EWGSOP2 "confirmed sarcopenia" definition was also associated with low MNA-scores (OR = 3.68, CI 2.30-5.89), as well as for the lean mass definition according EWGSOP2 cut-off (OR 5.22 CI 3.52-7.73). Both FNIH and EWGSOP2 "probable sarcopenia" definitions were not associated with the risk of malnutrition.

CONCLUSIONS

In this study, the prevalence of sarcopenia ranged from 12.6 to 44.9 % according to various definitions. A score of MNA under 24, was associated with almost all of the sarcopenia definitions. This study reinforces the concept that malnutrition and sarcopenia are strictly related. When facing malnutrition in daily clinical practice, body composition should be assessed and the proposed nutritional intervention should be tailored by these results in order to prevent the onset of late-life disability.

Skeletal muscle estimation: A review of techniques and their applications

Quantifying skeletal muscle size is necessary to identify those at risk for conditions that increase frailty, morbidity, and mortality, as well as decrease quality of life. Although muscle strength, muscle quality, and physical performance have been suggested as important assessments in the screening, prevention, and management of sarcopenic and cachexic individuals, skeletal muscle size is still a critical objective marker. Several techniques exist for estimating skeletal muscle size; however, each technique presents with unique characteristics regarding simplicity/complexity, cost, radiation dose, accessibility, and portability that are important factors for assessors to consider before applying these modalities in practice. This narrative review presents a discussion centred on the theory and applications of current non-invasive techniques for estimating skeletal muscle size in diverse populations. Common instruments for skeletal muscle assessment include imaging techniques such as computed tomography, magnetic resonance imaging, peripheral quantitative computed tomography, dual-energy X-ray absorptiometry, and Brightness-mode ultrasound, and non-imaging techniques like bioelectrical impedance analysis and anthropometry. Skeletal muscle size can be acquired from these methods using whole-body and/or regional assessments, as well as prediction equations. Notable concerns when conducting assessments include the absence of standardised image acquisition/processing protocols and the variation in cut-off thresholds used to define low skeletal muscle size by clinicians and researchers, which could affect the accuracy and prevalence of diagnoses. Given the importance of evaluating skeletal muscle size, it is imperative practitioners are informed of each technique and their respective strengths and weaknesses.

Exploring the utility of bedside tests for predicting cardiorespiratory fitness in older adults

Objectives

Cardiorespiratory fitness (CRF) declines with advancing and has also, independent of age, been shown to be predictive of all-cause mortality, morbidity, and poor clinical outcomes. In relation to the older patient, there is a particular wealth of evidence highlighting the relationship between low CRF and poor surgical outcomes. Cardiopulmonary exercise testing (CPET) is accepted as the gold-standard measure of CRF. However, this form of assessment has significant personnel and equipment demands and is not feasible for those with certain age-associated physical limitations, including joint and cardiovascular comorbidities. As such, alternative ways to assess the CRF of older patients are very much needed.

Methods

Sixty-four participants (45% female) with a median age of 74 (65-90) years were recruited to this study via community-based advertisements. All participants completed three tests of physical function: (1) a step-box test; (2) handgrip strength dynamometry; and (3) a CPET on a cycle ergometer; and also had their muscle architecture (vastus lateralis) assessed by B-mode ultrasonography to provide measures of muscle thickness, pennation angle, and fascicle length. Multivariate linear regression was then used to ascertain bedside predictors of CPET parameters from the alternative measures of physical function and demographic (age, gender, body mass index (BMI)) data.

Results

There was no significant association between ultrasound-assessed parameters of muscle architecture and measures of CRF. VO2peak was predicted to some extent from fast step time during the step-box test, gender, and BMI, leading to a model that achieved an R 2 of 0.40 (p < 0.001). Further, in aiming to develop a model with minimal assessment demands (i.e., using handgrip dynamometry rather than the step-box test), replacing fast step time with non-dominant HGS led to a model which achieved an R 2 of 0.36 (p < 0.001). Non-dominant handgrip strength combined with the step-box test parameter of fast step time and BMI delivered the most predictive model for VO2peak with an R 2 of 0.45 (p < 0.001).

Conclusions

Our findings show that simple-to-ascertain patient characteristics and bedside assessments of physical function are able to predict CPET-derived CRF. Combined with gender and BMI, both handgrip strength and fast step time during a step-box test were predictive for VO2peak. Future work should apply this model to a clinical population to determine its utility in this setting and to explore if simple bedside tests are predictive of important clinical outcomes in older adults (i.e., post-surgical complications).

Imaging of Sarcopenia in Type 2 Diabetes Mellitus

Sarcopenia is an age-related condition characterized by the loss of skeletal muscle mass, muscular strength, and muscle function. In older adults, type 2 diabetes mellitus (T2DM) constitutes a significant health burden. Skeletal muscle damage and deterioration have emerged as novel chronic complications in patients with diabetes, often linked to their increased longevity. Diabetic sarcopenia has been associated with increased rates of hospitalization, cardiovascular events, and mortality. Nevertheless, effectively managing metabolic disorders in patients with T2DM through appropriate therapeutic interventions could potentially mitigate the risk of sarcopenia. Utilizing imaging technologies holds substantial clinical significance in the early detection of skeletal muscle mass alterations associated with sarcopenia. Such detection is pivotal for arresting disease progression and preserving patients' quality of life. These imaging modalities offer reproducible and consistent patterns over time, as they all provide varying degrees of quantitative data. This review primarily delves into the application of dual-energy X-ray absorptiometry, computed tomography, magnetic resonance imaging, and ultrasound for both qualitative and quantitative assessments of muscle mass in patients with T2DM. It also juxtaposes the merits and limitations of these four techniques. By understanding the nuances of each method, clinicians can discern how best to apply them in diverse clinical scenarios.

Skeletal muscle estimation using magnetic-resonance-imaging-based equations for dual-energy X-ray absorptiometry and bioelectrical impedance analysis

BACKGROUND/OBJECTIVES

Skeletal muscle mass (SMM) estimation is important but challenging in clinical settings. Criterion methods, such as magnetic resonance imaging (MRI), are often inaccessible. However, surrogate methods, such as dual-energy X-ray absorptiometry (DXA) and multi-frequency bioelectrical impedance analysis (MFBIA), can use MRI-based equations to estimate SMM, although the agreement between these methods is unclear.

SUBJECTS/METHODS

Total and segmental SMM were estimated with DXA and MFBIA using MRI-based equations in 313 healthy adults (120 M, 193 F; age 30.2 ± 13.0 y; BMI 24.6 ± 4.0 kg/m2). DXA total SMM was estimated using the Kim and McCarthy equations, and segmental SMM was estimated using the McCarthy equations. Relationships between DXA and MFBIA SMM were examined using Deming regression, Lin's concordance correlation coefficient (CCC), equivalence testing, Bland-Altman analysis, and related tests.

RESULTS

Strong linear relationships were observed for total (R2 0.95, CCC 0.96-0.97), leg (R2 0.90, CCC 0.85) and arm (R2 0.93, CCC 0.93) SMM in the entire sample. Kim equation SMM demonstrated statistical equivalence with MFBIA for total SMM, but the Deming regression slope differed from 1 and proportional bias was present. McCarthy equation total SMM exhibited a regression slope that did not differ from 1, and no proportional bias was present in the entire sample. However, equivalence with MFBIA was not observed. Systematically higher leg and arm SMM values were observed with DXA as compared to MFBIA.

CONCLUSIONS

While DXA and MFBIA total SMM generally exhibited strong agreement, higher appendicular SMM by DXA highlights technical differences between methods.

Comparison of Motion Grading in 1,000 Patients by First- and Second-Generation HR-pQCT: A Propensity Score Matched Cohort Study

In-vivo bone microstructure measured by high-resolution peripheral quantitative computed tomography (HR-pQCT) is gaining importance in research and clinical practice. Second-generation HR-pQCT (XCT2) shows improved image quality and shorter measurement duration compared to the first generation (XCT1). Predicting and understanding the occurrence of motion artifacts is crucial for clinical practice. We retrospectively analyzed data from HR-pQCT measurements at the distal radius and tibia of 1,000 patients (aged 20 to 89) evenly distributed between both generations of HR-pQCT. Motion artifacts were graded between 1 (no motion) and 5 (severe motion), with grades greater 3 considered unusable. Additionally, baseline characteristics and patients' muscle performance and balance were measured. Various group comparisons between the two generations of HR-pQCT and regression analyses between patient characteristics and motion grading were performed. The study groups of XCT1 and XCT2 did not differ by age (XCT1: 64.9 vs. XCT2: 63.8 years, p = 0.136), sex (both 74.5% females, p > 0.999), or BMI (both 24.2 kg/m2, p = 0.911) after propensity score matching. XCT2 scans exhibited significantly lower motion grading in both extremities compared to XCT1 (Radius: p < 0.001; Tibia: p = 0.002). In XCT2 motion-corrupted scans were more than halved at the radius (XCT1: 35.3% vs. XCT2: 15.5%, p < 0.001), and at the tibia the frequency of best image quality scans was increased (XCT1: 50.2% vs. XCT2: 63.7%, p < 0.001). The strongest independent predictor for motion-corrupted images is the occurrence of high motion grading at the other scanning site during the same consultation. The association between high motion grading in one scan and a corresponding high motion grading in another scan within the same session suggests a non-resting patient. Additionally, aged, female, and patients with smaller stature tend towards higher motion grading, requiring special attention to a correct extremity fixation.

Early detection and assessment of intensive care unit-acquired weakness: a comprehensive review

Intensive care unit-acquired weakness (ICU-AW) is a serious complication in critically ill patients. Therefore, timely and accurate diagnosis and monitoring of ICU-AW are crucial for effectively preventing its associated morbidity and mortality. This article provides a comprehensive review of ICU-AW, focusing on the different methods used for its diagnosis and monitoring. Additionally, it highlights the role of bedside ultrasound in muscle assessment and early detection of ICU-AW. Furthermore, the article explores potential strategies for preventing ICU-AW. Healthcare providers who manage critically ill patients utilize diagnostic approaches such as physical exams, imaging, and assessment tools to identify ICU-AW. However, each method has its own limitations. The diagnosis of ICU-AW needs improvement due to the lack of a consensus on the appropriate approach for its detection. Nevertheless, bedside ultrasound has proven to be the most reliable and cost-effective tool for muscle assessment in the ICU. Combining the Sequential Organ Failure Assessment (SOFA) score, Acute Physiology and Chronic Health Evaluation (APACHE) II score assessment, and ultrasound can be a convenient approach for the early detection of ICU-AW. This approach can facilitate timely intervention and prevent catastrophic consequences. However, further studies are needed to strengthen the evidence.

The utility of a portable muscle ultrasound in the assessment of muscle alterations in children with acute lymphoblastic leukaemia

BACKGROUND

During treatment for acute lymphoblastic leukaemia (ALL), children are prone to musculoskeletal deterioration. However, non-invasive tools to measure muscle mass and intramuscular alterations are limited. In this study we explored the feasibility of muscle ultrasound in children with ALL. Additionally, we analysed whether automated ultrasound outcomes of muscle size and intramuscular fat infiltration (IMAT) were associated with appendicular skeletal muscle mass (ASMM), muscle strength and physical performance.

METHODS

Children with ALL, aged 3-18 years were included during maintenance therapy. Bilateral images of the rectus femoris muscle were captured using a portable linear array transducer connected to a tablet. Subsequently, an automated image annotation software (MuscleSound) was used to estimate cross-sectional area, muscle thickness and IMAT. Feasibility was assessed using acceptance (percentage of children approached who were enrolled), practicality (percentage of children that completed the ultrasound measurement after enrolment) and implementation (percentage of children that had sufficient imaging to be processed and analysed by the software). Assessments of ASMM by bioimpedance analysis, muscle strength using handheld dynamometry and timed physical performance tests were administered at the same visit. Multivariable linear models were estimated to study the associations between muscle ultrasound outcomes and ASMM, strength and physical performance, adjusted for sex, age, body mass index and ALL treatment week.

RESULTS

Muscle ultrasound was performed in 60 out of 73 invited patients (76.9%), of which 37 were boys (61.7%), and median age was 6.1 years (range: 3-18.8 years). The acceptance was 98.7%, practicality 77.9% and implementation was 100%. Patients who refused the examination (n = 13) were younger (median: 3.6, range: 3-11.2 years) compared with the 60 examined children (P = 0.0009). In multivariable models, cross-sectional area was associated with ASMM (β = 0.49 Z-score, 95% confidence interval [CI]:0.3,2.4), knee-extension strength (β = 16.9 Newton [N], 95% CI: 4.8, 28.9), walking performance (β = -0.46 s, 95% CI: -0.75, -0.18) and rising from the floor (β = -1.07 s, 95% CI: -1.71, -0.42). Muscle thickness was associated with ASMM (β = 0.14 Z-score, 95% CI: 0.04, 0.24), knee-extension strength (β = 4.73 N, 95% CI: 0.99, 8.47), walking performance (β = -0.13 s, 95% CI: -0.22, -0.04) and rising from the floor (β = -0.28 s, 95% CI: -0.48, -0.08). IMAT was associated with knee-extension strength (β = -6.84 N, 95% CI: -12.26, -1.41), walking performance (β = 0.2 s, 95% CI: 0.08, 0.32) and rising from the floor (β = 0.54 s, 95% CI: 0.27, 0.8). None of the muscle ultrasound outcomes was associated with handgrip strength.

CONCLUSIONS

Portable muscle ultrasound appears a feasible and useful tool to measure muscle size and intramuscular alterations in children with ALL. Validation studies using magnetic resonance imaging (gold standard) are necessary to confirm accuracy in paediatric populations.

Sarcopenia, More Than Just Muscle Atrophy: Imaging Methods for the Assessment of Muscle Quantity and Quality

BACKGROUND

Sarcopenia, a progressive reduction of muscle mass and function, is associated with adverse outcomes in the elderly. Sarcopenia and muscle atrophy are not equal processes. Low muscle strength in association with muscle quantity/quality reduction is currently the optimal method for assessing sarcopenia. There is a practical need for indirect measurement of muscle strength using state-of-the-art imaging techniques.

METHODS

The following provides a narrative, broad review of all current imaging techniques for evaluating muscles and identifying sarcopenia, including DEXA, CT, MRI, and high-resolution ultrasound, their main strengths, weaknesses, and possible solutions to problems regarding each technique.

RESULTS AND CONCLUSION

Well-recognized imaging methods for the assessment of muscle mass are explained, including evaluation with DEXA, CT, and MRI muscle quantity assessment, ultrasound evaluation of muscle thickness and CSA, and their correlations with established muscle mass calculation methods. A special focus is on imaging methods for muscle quality evaluation. Several innovative and promising techniques that are still in the research phase but show potential in the assessment of different properties of muscle quality, including MRI DIXON sequences, MRI spectroscopy, Diffusion Tensor Imaging, ultrasound echo intensity, ultrasound elastography, and speed-of-sound ultrasound imaging are briefly mentioned.

KEY POINTS

· Sarcopenia definition includes low muscle strength and low muscle quantity/quality.. · DEXA is a low-radiation method for whole-body composition measurement in a single image.. · CT has established cut-off values for muscle quality/quantity evaluation and sarcopenia diagnosis.. · MRI is the most sophisticated muscle quality assessment method capable of evaluating myosteatosis, myofibrosis, and microstructure.. · Ultrasound can evaluate muscle quality, including tissue architecture, and elasticity with excellent spatial resolution..

CITATION FORMAT

· Vasilevska Nikodinovska V, Ivanoski S, . Sarcopenia, More Than Just Muscle Atrophy: Imaging Methods for the Assessment of Muscle Quantity and Quality. Fortschr Röntgenstr 2023; 195: 777 - 789.

Inter- and intra-observer reliability of thoracic limb circumference measurement methods in sound dogs

Objective

The primary objectives of this study are to (1) compare the inter- and intra-observer reliability of thoracic limb circumference measurement methods in sound dogs, and (2) determine the most reliable thoracic limb positioning and location on the thoracic limb for performing circumferential measurements.

Methods

Thoracic limbs of 10 apparently sound dogs (20 limbs) were blindly and independently measured by 3 observers. Triplicate measurements were performed with dogs in lateral recumbency at 50 and 70% brachial (Br) length (length between the greater tubercle and lateral humoral epicondyle) and 25% ABr length (length between the lateral humeral epicondyle and ulnar styloid process), both with the elbow extended and at an approximate weight-bearing (WB) angle. Intra-class correlation coefficients (ICC) with a 95% confidence interval (CI) were used for data analysis with a p < 0.05 being significant.

Results

All measures had significantly good to excellent intra- (ICC 0.836-0.994, p < 0.001) and inter-observer reliability (ICC 0.834-0.996, p < 0.001). Inter-observer reliability was excellent at 25% ABr extended and WB positions, and at 50% Br WB position, with a wider confidence interval at the latter location. Intra-observer reliability was excellent across all observers for 25% ABr extended and WB, and 50% Br WB positions, also with a wider confidence interval at the latter location.

Conclusion

Circumferential measurement of the canine thoracic limb was most reliable at 25% ABr length with the elbow either in an extended or WB position.

Physiological-induced conductive response evaluation in specific muscle compartments under hybrid of electrical muscle stimulation and voluntary resistance training by electrical impedance tomography

Objective: The physiological-induced conductive response has been visualised for evaluation in specific muscle compartments under hybrid (hybridEMS) of electrical muscle stimulation (EMS) and voluntary resistance training (VRT) by electrical impedance tomography (EIT). Methods: In the experiments, tendency of conductivity distribution images σ over time was clearly detected for three specific muscle compartments, which are called AM 1 compartment composed of biceps brachii muscle, AM 2 compartment composed of triceps brachii muscle, and AM 3 compartment composed of brachialis muscle, under three training modalities. Results: From the experimental results, the tendency of physiological-induced conductive response are increased in all three training modalities with increasing training time. Correspondingly, the spatial-mean conductivity <σ>AM1,AM2,AM3 increased with the conductance value G and extracellular water ratio β of right arm by bio-impedance analysis (BIA) method. In addition, hybridEMS has the greatest effect on physiological-induced conductive response in AM 1, AM 2, and AM 3. Under hybridEMS, the spatial-mean conductivity increased from <σ pre > AM1 = 0.154 to <σ 23mins > AM1 = 0.810 in AM 1 muscle compartment (n = 8, p < 0.001); <σ pre > AM2 = 0.040 to <σ 23mins > AM2 = 0.254 in AM 2 muscle compartment (n = 8, p < 0.05); <σ pre > AM3 = 0.078 to <σ 23mins > AM3 = 0.497 in AM 3 muscle compartment (n = 8, p < 0.05). Conclusion: The paired-samples t-test results of <σ>AM1,AM2,AM3 under all three training modalities suggest hybridEMS has the most efficient elicitation on physiological induced conductive response compared to VRT and EMS. The effect of EMS on deep muscle compartment (AM 3) is slower compared to VRT and hybridEMS, with a significant difference after 15 min of training.

Machine learning algorithms for diagnosis of hip bone osteoporosis: a systematic review and meta-analysis study

BACKGROUND

Osteoporosis is a significant health problem in the skeletal system, associated with bone tissue changes and its strength. Machine Learning (ML), on the other hand, has been accompanied by improvements in recent years and has been in the spotlight. This study is designed to investigate the Diagnostic Test Accuracy (DTA) of ML to detect osteoporosis through the hip dual-energy X-ray absorptiometry (DXA) images.

METHODS

The ISI Web of Science, PubMed, Scopus, Cochrane Library, IEEE Xplore Digital Library, CINAHL, Science Direct, PROSPERO, and EMBASE were systematically searched until June 2023 for studies that tested the diagnostic precision of ML model-assisted for predicting an osteoporosis diagnosis.

RESULTS

The pooled sensitivity of univariate analysis of seven studies was 0.844 (95% CI 0.791 to 0.885, I² = 94% for 7 studies). The pooled specificity of univariate analysis was 0.781 (95% CI 0.732 to 0.824, I² = 98% for 7 studies). The pooled diagnostic odds ratio (DOR) was 18.91 (95% CI 14.22 to 25.14, I² = 93% for 7 studies). The pooled mean positive likelihood ratio (LR⁺) and the negative likelihood ratio (LR^-) were 3.7 and 0.22, respectively. Also, the summary receiver operating characteristics (sROC) of the bivariate model has an AUC of 0.878.

CONCLUSION

Osteoporosis can be diagnosed by ML with acceptable accuracy, and hip fracture prediction was improved via training in an Architecture Learning Network (ALN).

Thigh muscles are more susceptible to age-related muscle loss when compared to lower leg and pelvic muscles

BACKGROUND

A key hallmark of aging is the progressive loss of skeletal muscle mass. Due to limitations of the various methods typically applied to assess muscle mass, only limited information is available on age-related differences between various muscle groups. This study assessed differences in individual lower body muscle group volumes between healthy young and older males.

METHODS

Lower body muscle mass assessments were performed in 10 young (age: 27 ± 4 y) and 10 older (age: 71 ± 6 y) healthy, male adults using Dual-energy X-ray Absorptiometry (DXA), single slice (thigh) Computed Tomography (CT), as well as Magnetic Resonance Imaging (MRI). Muscle volumes of all individual muscle groups in the lower body were assessed by MRI.

RESULTS

Leg lean mass, as assessed with DXA, was not significantly different between older (9.2 ± 1.0 kg) and young (10.5 ± 2.0 kg) men (P = 0.075). Thigh muscle cross-sectional area, as assessed with CT, was significantly lower (by 13 %) in the older (137 ± 17 cm²) compared to young (157 ± 24 cm²) participants (P = 0.044). MRI-derived lower body muscle volume was also significantly lower (by 20 %) in older (6.7 ± 0.9 L) compared to young (8.3 ± 1.3 L) men (P = 0.005). This was primarily attributed to substantial differences in thigh (24 %), rather than lower leg (12 %) and pelvis (15 %) muscle volume in the older vs the young. Thigh muscle volume averaged 3.4 ± 0.5 L in older and 4.5 ± 0.7 L in young men (P = 0.001). Of all thigh muscle groups, the quadriceps femoris showed the most profound difference (30 %) between young (2.3 ± 0.4 L) and older (1.6 ± 0.2 L) men (P < 0.001).

CONCLUSIONS

The most profound differences in lower body muscle volume between young and older men are observed in the thigh. Within the thigh muscle groups, the quadriceps femoris shows the largest difference in muscle volume between young and older men. Finally, DXA appears less sensitive when compared to CT and MRI to assess age-related differences in muscle mass.

Limited effect of over-the-counter doses of ibuprofen on mechanisms regulating muscle hypertrophy during resistance training in young adults

We have previously shown that maximal over-the-counter doses of ibuprofen, compared with low doses of acetylsalicylic acid, reduce muscle hypertrophy in young individuals after 8 wk of resistance training. Because the mechanism behind this effect has not been fully elucidated, we here investigated skeletal muscle molecular responses and myofiber adaptations in response to acute and chronic resistance training with concomitant drug intake. Thirty-one young (aged 18-35 yr) healthy men (n = 17) and women (n = 14) were randomized to receive either ibuprofen (IBU; 1,200 mg daily; n = 15) or acetylsalicylic acid (ASA; 75 mg daily; n = 16) while undergoing 8 wk of knee extension training. Muscle biopsies from the vastus lateralis were obtained before, at week 4 after an acute exercise session, and after 8 wk of resistance training and analyzed for mRNA markers and mTOR signaling, as well as quantification of total RNA content (marker of ribosome biogenesis) and immunohistochemical analysis of muscle fiber size, satellite cell content, myonuclear accretion, and capillarization. There were only two treatment × time interaction in selected molecular markers after acute exercise (atrogin-1 and MuRF1 mRNA), but several exercise effects. Muscle fiber size, satellite cell and myonuclear accretion, and capillarization were not affected by chronic training or drug intake. RNA content increased comparably (∼14%) in both groups. Collectively, these data suggest that established acute and chronic hypertrophy regulators (including mTOR signaling, ribosome biogenesis, satellite cell content, myonuclear accretion, and angiogenesis) were not differentially affected between groups and therefore do not explain the deleterious effects of ibuprofen on muscle hypertrophy in young adults.NEW & NOTEWORTHY Here we show that mTOR signaling, fiber size, ribosome biogenesis, satellite cell content, myonuclear accretion, and angiogenesis were not differentially affected between groups undergoing 8 wk of resistance training with concomitant anti-inflammatory medication (ibuprofen versus low-dose aspirin). Atrogin-1 and MuRF-1 mRNA were more downregulated after acute exercise in the low-dose aspirin group than in the ibuprofen group. Taken together it appears that these established hypertrophy regulators do not explain the previously reported deleterious effects of high doses of ibuprofen on muscle hypertrophy in young adults.

Validity of the relative fat mass pediatric index (RFMp) for the analysis of body composition in physically active youths at different stages of biological maturation

BACKGROUND

The paediatric relative fat mass (RFMp) index was valid for analysis of percent body fat (BF%). However, the validation did not consider biological maturation (BM) stages. The present study aimed to verify the validity of the RFMp index in the estimation of BF% in children and adolescents of both sexes at different stages of BM.

METHODS

A cross-sectional study was conducted with a sample of 146 young (males: 64.5%. females: 35.5%. age: 13.0 ± 2.2 years) practising sports modalities. We tested the validity of four RFMp equations (1: for boys aged 8-14 years; 2: for girls aged 8-14 years; 3: for both sexes aged 8-14 years; and 4: for both sexes aged 15-19 years) to analyse BF% using dual-energy X-ray absorptiometry as a reference method. BM was analysed by peak height velocity (PHV). Thus, we created subgroups by BM stage (pre-PHV, circum-PHV and post-PHV).

RESULTS

Analyses of agreement between methods showed that only the RFMp-3 equation was reliable to analyse BF% in subjects of both sexes aged 8-14 years at the circum-PHV BM stage (proportion bias 95% confidence interval = -0.3 to 0.5, p = 0.7. concordance correlation coefficient = 0.3; validity = 0.9).

CONCLUSIONS

The RFMp equation developed for the paediatric population of both sexes aged 8-14 years was valid for predicting BF% in children and adolescents of both sexes at the Circum-PHV stage of the BM.

Examining Factors Associated with Dynapenia/Sarcopenia in Patients with Schizophrenia: A Pilot Case-Control Study

Sedentary behavior in patients with schizophrenia causes muscle weakness, is associated with a higher risk of metabolic syndrome, and contributes to mortality risk. This pilot case-control study aims to examine the associated factors for dynapenia/sarcopenia in patients with schizophrenia. The participants were 30 healthy individuals (healthy group) and 30 patients with schizophrenia (patient group), who were matched for age and sex. Descriptive statistics, Welch's t-test, cross-tabulations, adjusted residuals, Fisher's exact probability test (extended), and/or odds ratios (ORs) were calculated. In this study, dynapenia was significantly more prevalent in patients with schizophrenia than in healthy individuals. Regarding body water, Pearson's chi-square value was 4.41 (p = 0.04), and significantly more patients with dynapenia were below the normal range. In particular, body water and dynapenia showed a significant association, with an OR = 3.42 and 95% confidence interval [1.06, 11.09]. Notably, compared with participants of the healthy group, patients with schizophrenia were overweight, had less body water, and were at a higher risk for dynapenia. The impedance method and the digital grip dynamometer used in this study were simple and useful tools for evaluating muscle quality. To improve health conditions for patients with schizophrenia, additional attention should be paid to muscle weakness, nutritional status, and physical rehabilitation.

Fat infiltration in the thigh muscles is associated with symptomatic spinal stenosis and reduced physical functioning in adults with achondroplasia

BACKGROUND

Symptomatic spinal stenosis is a prevalent complication in adults with achondroplasia. Increased muscle fat infiltration (MFI) and reduced thigh muscle volumes have also been reported, but the pathophysiology is poorly understood. We explored whether the increased MFI and reduced thigh muscle volumes were associated with the presence of symptomatic spinal stenosis and physical functioning.

METHODS

MFI and thigh muscle volumes were assessed by MRI in 40 adults with achondroplasia, and compared to 80 average-statured controls, matched for BMI, gender, and age. In achondroplasia participants, the six-minute walk-test (6MWT), the 30-s sit-to-stand test (30sSTS), and a questionnaire (the IPAQ) assessed physical functioning.

RESULTS

Symptomatic spinal stenosis was present in 25 of the participants (the stenosis group), while 15 did not have stenosis (the non-stenosis group). In the stenosis group, 84% (21/25) had undergone at least one spinal decompression surgery. The stenosis group had significantly higher MFI than the non-stenosis group, with an age-, gender and BMI-adjusted difference in total MFI of 3.3 percentage points (pp) (95% confidence interval [CI] 0.04 to 6.3 pp; p = 0.03). Compared to matched controls, the mean age-adjusted difference was 3.3 pp (95% CI 1.7 to 4.9 pp; p < 0.01). The non-stenosis group had MFI similar to controls (age-adjusted difference - 0.9 pp, 95% CI - 3.4 to 1.8 pp; p = 0.51). MFI was strongly correlated with the 6MWT (r = - 0.81, - 0.83, and - 0.86; all p-values < 0.01), and moderately correlated with the 30sSTS (r = - 0.56, - 0.57, and - 0.59; all p-values < 0.01). There were no significant differences in muscle volumes or physical activity level between the stenosis group and the non-stenosis group.

CONCLUSION

Increased MFI in the thigh muscles was associated with the presence of symptomatic spinal stenosis, reduced functional walking capacity, and reduced lower limb muscle strength. The causality between spinal stenosis, accumulation of thigh MFI, and surgical outcomes need further study. We have demonstrated that MRI might serve as an objective muscle biomarker in future achondroplasia studies, in addition to functional outcome measures. The method could potentially aid in optimizing the timing of spinal decompression surgery and in planning of post-surgery rehabilitation.

Impact of Sarcopenia on Non-Alcoholic Fatty Liver Disease

With the increasing incidence of non-alcoholic fatty liver disease (NAFLD) and the aging of the population, sarcopenia is attracting attention as one of the pathological conditions involved in the development and progression of NAFLD. In NAFLD, sarcopenia is closely associated with insulin resistance and results from the atrophy of skeletal muscle, an insulin target organ. In addition, inflammatory cytokines that promote skeletal muscle protein breakdown, low adiponectin levels leading to decreased insulin sensitivity, and hyperleptinemia are also involved in NAFLD pathogenesis. The presence of sarcopenia is a prognostic factor and increases the risk of mortality in patients with cirrhosis and post-treatment liver cancer. Sarcopenia, the presence of which mainly occurs due to decreased muscle mass, combined with increased visceral fat, can lead to sarcopenia-associated obesity, which increases the risk of NASH, liver fibrosis, and cardiovascular disease. In order to treat sarcopenia, it is necessary to properly evaluate sarcopenia status. Patients with high BMI, as in sarcopenic obesity, may improve with caloric restriction. However, inadequate oral intake may lead to further loss of muscle mass. Aerobic and resistance exercise should also be used appropriately.

Determinants of muscle density and clinical outcomes: Findings from the Hertfordshire Cohort Study

PURPOSE

The age-related loss of skeletal muscle mass and strength is associated with adverse health outcomes. However, to date, peripheral quantitative computed tomography (pQCT)-derived muscle density has been little studied. We used a well characterised cohort of older adults to identify lifestyle and anthropometric determinants of pQCT-derived muscle density measured 11 years later, and to report relationships between pQCT-derived muscle density with history of falls and prevalent fractures.

METHODS

A lifestyle questionnaire was administered to 197 men and 178 women, aged 59-70 at baseline. After a median of 11.5 (IQR 10.9, 12.3) years, pQCT (Stratec XCT2000) of the radius and tibia was performed to measure forearm muscle density (FMD) and calf muscle density (CMD). Presence of falls and fractures since the age of 45 were determined through participant recall; vertebral fractures were also ascertained through vertebral fracture assessment using iDXA. Total hip BMD (TH aBMD) was assessed using DXA. Baseline characteristics in relation to muscle density at follow-up were examined using linear regression; associations between muscle density and prior falls and fractures were investigated using logistic regression. All analyses were adjusted for sex and age.

RESULTS

Mean (SD) age at muscle density measurement was 76.3 (2.6) years. Mean (SD) FMD was 79.9 (3.1) and 77.2 (3.2) among males and females, respectively; CMD was 80.7 (2.6) and 78.5 (2.6) among males and females, respectively. Significant sex-differences in muscle density were observed at each site (p < 0.001). Female sex, lower weight, and lower body mass index were associated (p < 0.05) with both lower FMD and CMD. Additional correlates of lower CMD included older age and shorter stature. Lifestyle measures were not associated with muscle density in this cohort. Lower FMD was related to increased risk of previous fracture (odds ratio (95 % CI) per SD lower FMD: 1.42 (1.07, 1.89), p = 0.015) but not after adjustment for TH aBMD (p > 0.08). No significant relationships were seen between muscle density and falls.

CONCLUSION

Female sex, older age, and lower BMI were associated with subsequent lower muscle density in older community-dwelling adults. Lower FMD was related to increased risk of previous fracture. Changes in muscle density over time might precede adverse outcomes such as falls and fractures and may be a long-term predictor of frailty. It could be also suggested that muscle density could be a more clinically meaningful surrogate of functional decline and disability than muscle size or mass, but more studies are needed to support this notion.

Visceral adipose tissue is a better predictor than BMI in the alternative Fistula Risk Score in patients undergoing pancreatoduodenectomy

BACKGROUND

Muscle attenuation (MA) and visceral adipose tissue (VAT) have not yet been included in the currently used alternative Fistula Risk Score (a-FRS). The aim of this study was to examine the added value of these parameters as predictors of clinically relevant postoperative pancreatic fistula (CR-POPF) in the a-FRS after pancreatoduodenectomy compared to Body Mass Index (BMI).

METHODS

A single center retrospective cohort study was performed in patients who underwent pancreatoduodenectomy between 2009 and 2018. The a-FRS model was reproduced, MA and VAT were both combined and separately added to the model instead of BMI using logistic regression analysis. Model discrimination was assessed by ROC-curves.

RESULTS

In total, 329 patients were included of which 55 (16.7%) developed CR-POPF. The a-FRS model showed an AUC of 0.74 (95%CI: 0.68-0.80). In this model, BMI was not significantly associated with CR-POPF (p = 0.16). The MA + VAT model showed an AUC of 0.81 (95%CI: 0.75-0.86). VAT was significantly associated with CR-POPF (per cm², OR: 1.01; 95%CI: 1.00-1.01; p < 0.001). The AUC of the MA + VAT model differed significantly from the AUC of the a-FRS model (p = 0.001).

CONCLUSION

Visceral adipose tissue is of added value in the a-FRS compared to BMI in predicting CR-POPF in patients undergoing pancreatoduodenectomy.

Is predicted body-composition and relative fat mass an alternative to body-mass index and waist circumference for disease risk estimation?

BACKGROUND AND AIMS

New methods to estimate body-composition have recently been proposed, but their relation to diseases, such as diabetes and coronary heart disease, needs further investigation. The purpose of this study was to investigate the association between proposed prediction of body-composition (PBC); Relative Fat Mass (RFM), Body Mass Index (BMI), Waist Circumference (WC) and disease.

METHODS

In a cross-sectional cohort (NHANES) the association between the four body measures and diabetes, high blood pressure, coronary heart disease, cancer, arthritis, and hospitalization were assessed. A total of 13,348 people was included in this study. Receiver operating characteristic (ROC), Area Under Curve (AUC) and statistical testing were used to evaluate the differences.

RESULTS

PBC/RFM had significant higher AUC than BMI or WC for diabetes, high blood pressure, hospitalization, and arthritis. PBC had a significant higher AUC than RFM, BMI, WC for Cancer and coronary heart disease.

CONCLUSIONS

RFM and PBC could be a better indicator to distinguish amongst people with a risk of diseases compared to traditional measures such as BMI and WC. However, future studies need to investigate the longitudinal association between RFM, PBC and the risk of disease development to assess if these measures are better suited for risk-stratification.

Season-Long Changes in the Body Composition Profiles of Competitive Female Rugby Union Players Assessed via Dual Energy X-Ray Absorptiometry

Background: Reference data for the body composition values of female athletes are limited to very few sports, with female Rugby Union players having mostly been omitted from such analyses.Methods: Using dual energy X-ray absorptiometry (DXA) scans, this study assessed the body composition profiles (body mass, bone mineral content; BMC, fat mass; FM, lean mass; LM, bone mineral density; BMD) of 15 competitive female Rugby Union players before and after the 2018/19 competitive season. Total competitive match-play minutes were also recorded for each player.Results: Body mass (73.7 ± 9.6 kg vs 74.9 ± 10.2 kg, p ≤ 0.05, d = 0.13) and BMC (3.2 ± 0.4 kg vs 3.3 ± 0.4 kg, p ≤ 0.05, d = 0.15) increased pre- to post-season for all players. Conversely, FM (21.0 ± 8.8 kg), LM (50.7 ± 3.9 kg), and BMD (1.31 ± 0.06 g·cm^-2) were similar between time-points (all p > .05). Accounting for position, body mass (r_partial(12) = 0.196), FM (r_partial(12) = -0.013), LM (r_partial(12) = 0.351), BMD (r_partial(12) = 0.168) and BMC (r_partial(12) = -0.204) showed no correlation (all p > .05) against match-play minutes.Conclusion: The demands of the competitive season influenced specific body composition indices (i.e., body mass, BMC) in female Rugby Union players; a finding which was unrelated to the number of minutes played in matches. While the causes of such differences remain unclear, practitioners should be cognizant of the body composition changes occurring throughout a female Rugby Union competitive season and, where necessary, consider modifying variables associated with adaptation and recovery accordingly.

Appendicular skeletal muscle mass assessment in dogs: a scoping literature review

BACKGROUND

Monitoring changes in appendicular skeletal muscle mass is frequently used as a surrogate marker for limb function. The primary objective of this study was to review scientific information related to the assessment of appendicular skeletal muscle mass in dogs. The secondary objective was to develop practical recommendations for serial evaluation of muscle mass.

METHODS

A scoping review was conducted with a systematic search of PubMed, Web of Science, CAB abstract, and Cochrane from inception to June 2021. The following modalities were included in the search: limb circumference, diagnostic ultrasound, computed tomography, magnetic resonance imaging, and dual-energy x-ray absorptiometry.

RESULTS

A total of 62 articles that measured appendicular skeletal muscle mass in dogs were identified. Limb circumference (55 articles) was the most commonly used modality. Its reliability was investigated in five studies. Several factors, including measuring tape type, body position, joint angles, and the presence of hair coat, were reported as variables that can affect measurements. Diagnostic ultrasound (five articles) was validated in three articles, but there is scarce information about observer reliability and variables affecting the measurement. Computed tomography (four articles) and magnetic resonance imaging (one article) have been used to validate other modalities at a single time point rather than as a clinical tool for serial muscle mass monitoring. Dual-energy x-ray absorptiometry (two articles) has been used to quantify specific skeletal muscle mass but was mainly used to evaluate body composition in dogs.

CONCLUSION

Limb circumference and ultrasound are likely the main modalities that will continue to be used for serial muscle mass measurement in the clinical setting unless a new technology is developed. The reliability of limb circumference is questionable. Several key factors, including measuring tape type, body position, joint angles, and coat clipping, need to be controlled to improve the reliability of limb circumference measurements. Ultrasound may provide a reasonable alternative, but further studies are required to evaluate the reliability of this modality and identify factors that influence ultrasound measurements.

Comparisons between skeletal muscle imaging techniques and histology in tracking midthigh hypertrophic adaptations following 10 weeks of resistance training

This study had two aims. AIM1 was to determine the agreement between mid-thigh vastus lateralis (VL) cross-sectional area measured by ultrasound (mCSA_US) versus magnetic resonance imaging (mCSA_MRI) at a single time point, and the ability of each to detect hypertrophic changes. AIM2 was to assess the relationships between pre-to-post training changes in thigh lean mass determined by DXA, VL mCSA_US, ultrasound-determined VL thickness (VL_Thick), and VL mean myofiber cross-sectional area (fCSA) with changes in VL mCSA_MRI. Twelve untrained males (Age: 20±1 y, BMI: 26.9±5.4 kg/m²; n=12) engaged in a 10-week resistance training program (2x/week) where right mid-thigh images and VL biopsies were obtained prior to and 72-hours following the last training bout. Participants' VL mCSA_MRI (p=0.005), DXA thigh lean mass (p=0.015), and VL_Thick (p=0.001) increased following training, whereas VL mCSA_US and fCSA did not. For AIM1, mCSA_US demonstrated excellent concordance (CCC = 0.830) with mCSA_MRI, albeit mCSA_US values were systematically lower compared to mCSA_MRI (mean bias: -2.29 cm²). Additionally, PRE-to-POST VL mCSA changes between techniques exhibited good agreement (CCC = 0.700; mean bias: -1.08 cm²). For AIM2, moderate, positive correlations existed for PRE-to-POST changes in VL mCSA_MRI and DXA thigh lean mass (r=0.580, p=0.048), mCSA_US (r=0.622, p=0.031), and VL_Thick (r=0.520, p=0.080). A moderate, negative correlation existed between mCSA_MRI and fCSA (r=-0.569, p=0.054). Our findings have multiple implications: i) resistance training-induced hypertrophy was dependent on the quantification method, ii) ultrasound-determined mCSA shows good agreement with MRI, and iii) tissue-level changes poorly agreed with mean fCSA changes and this requires further research.

The prognostic impact of myosteatosis on overall survival in gynecological cancer patients: A meta-analysis and trial sequential analysis

Myosteatosis is a novel imaging biomarker for survival in gynecological cancer patients; however, the evidence is inconsistent. This meta-analysis aims to investigate the impact of myosteatosis on overall survival in the gynecological oncology setting. Three databases (PubMed, EMBASE, and Web of Science) were systematically searched for relevant literature up to October 30th, 2021. A random-effects model was used to evaluate the predictive effect of myosteatosis on overall survival in the gynecological cancer population. The Newcastle-Ottawa Scale was used to assess the methodological quality of the included studies. Trial sequential analysis was used to control the risk of random errors. Twelve studies with a total of 2519 patients were included. Myosteatosis was associated with a 50% increased mortality risk (HR 1.50, 95% CI 1.24-1.82, P < 0.001) in gynecological cancer patients. Subgroup analyses stratified by study design, statistical model, treatment, sample size, and stage confirmed the predictive value of myosteatosis on survival. However, the prognostic ability of myosteatosis only was held in the American and European populations but lost in Asians. Additionally, myosteatosis was not associated with the increased mortality in endometrial and cervical cancers, except for ovarian cancers. Overall, myosteatosis is a powerful predictor of reduced overall survival in gynecological cancer patients. This article is protected by copyright. All rights reserved.

HR-pQCT for the Evaluation of Muscle Quality and Intramuscular Fat Infiltration in Ageing Skeletal Muscle

Myosteatosis is the infiltration of fat in skeletal muscle during the onset of sarcopenia. The quantification of intramuscular adipose tissue (IMAT) can be a feasible imaging modality for the clinical assessment of myosteatosis, important for the early identification of sarcopenia patients and timely intervention decisions. There is currently no standardized method or consensus for such an application. The aim of this study was to develop a method for the detection and analysis of IMAT in clinical HR-pQCT images of the distal tibia to evaluate skeletal muscle during the ageing process, validated with animal and clinical experimentation. A pre-clinical model of ovariectomized (OVX) rats with known intramuscular fat infiltration was used, where gastrocnemii were scanned by micro-computed tomography (micro-CT) at an 8.4 μm isotropic voxel size, and the images were analyzed using our modified IMAT analysis protocol. IMAT, muscle density (MD), and muscle volume (MV) were compared with SHAM controls validated with Oil-red-O (ORO) staining. Furthermore, the segmentation and IMAT evaluation method was applied to 30 human subjects at ages from 18 to 81 (mean = 47.3 ± 19.2). Muscle-related parameters were analyzed with functional outcomes. In the animal model, the micro-CT adipose tissue-related parameter of IMAT% segmented at −600 HU to 100 HU was shown to strongly associate with the ORO-positively stained area (r = 0.898, p = 0.002). For the human subjects, at an adjusted threshold of −600 to −20 HU, moderate positive correlations were found between MV and MD (r = 0.642, p < 0.001), and between MV and IMAT volume (r = 0.618, p < 0.01). Moderate negative correlations were detected between MD and IMAT% (r = −0.640, p < 0.001). Strong and moderate associations were found between age and MD (r = −0.763, p < 0.01), and age and IMAT (r = 0.559, p < 0.01). There was also a strong correlation between IMAT% and chair rise time (r = 0.671, p < 0.01). The proposed HR-pQCT evaluation protocol for intramuscular adipose-tissue produced MD and IMAT results that were associated with age and physical performance measures, and were of good predictive value for the progression of myosteatosis or sarcopenia. The protocol was also validated on animal skeletal muscle samples that showed a good representation of histological lipid content with positive correlations, further supporting the clinical application for the rapid evaluation of muscle quality and objective quantification of skeletal muscle at the peripheral for sarcopenia assessment.

Fatty Liver Index and Skeletal Muscle Density

Accumulation of fat in the liver and skeletal muscle is associated with obesity and poor health outcomes. Liver steatosis is a characteristic of non-alcoholic fatty liver disease (NAFLD) and myosteatosis, of poor muscle quality in sarcopenia. In this study of 403 men (33-96 years), we investigated associations between the fatty liver index (FLI) and muscle density, as markers of fat accumulation in these organs. We also investigated associations between the FLI and parameters of sarcopenia, including DXA-derived appendicular lean mass (ALM) and handgrip strength by dynamometry. Muscle density was measured using pQCT at the radius and tibia. FLI was calculated from BMI, waist circumference, and levels of triglycerides and gamma-glutamyltransferase. There was a pattern of decreasing muscle density across increasing quartiles of FLI. After adjusting for age and lifestyle, mean radial muscle density in Q4 was 2.1% lower than Q1 (p < 0.001) and mean tibial muscle density was 1.8% lower in Q3 and 3.0% lower in Q4, compared to Q1 (p = 0.022 and < 0.001, respectively). After adjusting for age and sedentary lifestyle, participants in the highest FLI quartile were sixfold more likely to have sarcopenia. In conclusion, our results suggest that fat accumulation in the liver co-exists with fat infiltration into skeletal muscle.

The Impact of Resistance Exercise on Muscle Mass in Glioblastoma in Survivors (RESIST): Protocol for a Randomized Controlled Trial

Background

Glioblastoma is the most common primary brain malignancy in adults, accounting for approximately 48% of all brain tumors. Standard treatment includes radiation and temozolomide chemotherapy. Glioblastomas are highly vascular and can cause vasogenic brain edema and mass effect, which can worsen the neurologic symptoms associated with the disease. The steroid dexamethasone (DEX) is the treatment of choice to reduce vasogenic edema and intracranial pressure associated with glioblastoma. However high-dose DEX or long-term use can result in muscle myopathy in 10%-60% of glioblastoma patients, significantly reducing functional fitness and quality of life (QOL). There is a wealth of evidence to support the use of exercise as an adjuvant therapy to improve functional ability as well as help manage treatment-related symptoms. Specifically, resistance training has been shown to increase muscle mass, strength, and functional fitness in aging adults and several cancer populations. Although studies are limited, research has shown that exercise is safe and feasible in glioblastoma populations. However, it is not clear whether resistance training can be successfully used in glioblastoma to prevent or mitigate steroid-induced muscle myopathy and associated loss of function.

Objective

The primary purpose of this study is to establish whether an individualized circuit-based program will reduce steroid-induced muscle myopathy, as indicated by maintained or improved functional fitness for patients on active treatment and receiving steroids.

Methods

This is a 2-armed, randomized controlled trial with repeated measures. We will recruit 38 adult (≥18 years) patients diagnosed with either primary or secondary glioblastoma who are scheduled to receive standard radiation and concurrent and adjuvant temozolomide chemotherapy postsurgical debulking and received any dose of DEX through the neurooncology clinic and the Nova Scotia Health Cancer Center. Patients will be randomly allocated to a standard of care waitlist control group or standard of care + circuit-based resistance training exercise group. The exercise group will receive a 12-week individualized, group and home-based exercise program. The control group will be advised to maintain an active lifestyle. The primary outcome, muscle myopathy (functional fitness), will be assessed using the Short Physical Performance Battery and hand grip strength. Secondary outcome measures will include body composition, cardiorespiratory fitness, physical activity, QOL, fatigue, and cognitive function. All measures will be assessed pre- and postintervention. Participant accrual, exercise adherence, and safety will be assessed throughout the study.

Results

This study has been funded by the Canadian Cancer Society Atlantic Cancer Research Grant and the J.D. Irving Limited–Excellence in Cancer Research Fund (grant number 707182). The protocol was approved by the Nova Scotia Health and Acadia University’s Research Ethics Boards. Enrollment is anticipated to begin in March 2022.

Conclusions

This study will inform how individualized circuit-based resistance training may improve functional independence and overall QOL of glioblastoma patients.

Trial Registration

ClinicalTrails.gov NCT05116137; https://www.clinicaltrials.gov/ct2/show/NCT05116137

International Registered Report Identifier (IRRID)

DERR1-10.2196/37709

Two-megahertz impedance index prediction equation for appendicular lean mass in Korean older people

Background

Whole-body bioelectrical impedance analysis (BIA) has been accepted as an indirect method to estimate appendicular lean mass (ALM) comparable to dual-energy X-ray absorptiometry (DXA). However, single or limited frequencies currently used for these estimates may over or under-estimate ALM. Accordingly, there is a need to measure the impedance parameter with appendicular lean-specific across multiple frequencies to more accurately estimate ALM. We aimed to validate muscle-specific frequency BIA equation for ALM using multifrequency BIA (MF-BIA) with DXA as the reference.

Methods

195 community-dwelling Korean older people (94 men and 101 women) aged 70 ~ 92y participated in this study. ALM was measured by DXA and bioimpedance measures at frequencies of 5 kHz ~ 3 MHz were assessed for independent predictive variables. Regression analyses were used to find limb-specific frequencies of bioimpedance, to develop the ALM equations and to conduct the internal cross-validation. The six published equations and the final equation of MF-BIA were externally cross-validated.

Results

195 participants completed the measurements of MF-BIA and DXA. Using bivariate regression analysis, the 2 MHz impedance index explained R² = 91.5% of variability (P < 0.001) in ALM and predictive accuracy of standard error of estimate (SEE) was 1.0822 kg ALM (P < 0.001). Multiple stepwise regression analysis obtained in the development group had an adjusted R² of 9.28% (P < 0.001) and a SEE of 0.97 kg ALM. The cross-validation group had no significant difference between the measured ALM and the predicted ALM (17.8 ± 3.9 kg vs. 17.7 ± 3.8 kg, P = .486) with 93.1% of R² (P < 0.001) and 1.00 kg ALM of total error. The final regression equation was as follows: ALM = 0.247ZI_@2 MHz + 1.254SEX_M1F0 + 0.067Xc_@5 kHz + 1.739 with 93% of R² (P < 0.001), 0.97 kg ALM of SEE (Subjective Rating as “excellent” for men and “very good” for women). In the analysis of the diagnostic level for sarcopenia of the final regression, the overall agreement was 94.9% (k = 0.779, P < 0.001) with 71.4% of sensitivity, 98.8% of specificity, 91.3 of positive prediction value and 95.3% of negative prediction value.

Conclusion

The newly developed appendicular lean-specific high-frequency BIA prediction equation has a high predictive accuracy, sensitivity, specificity, and agreement for both individual and group measurements. Thus, the high-frequency BIA prediction equation is suitable not only for epidemiological studies, but also for the diagnosis of sarcopenia in clinical settings.

Muscle Mass Measurement Using Machine Learning Algorithms with Electrical Impedance Myography

Sarcopenia is a wild chronic disease among elderly people. Although it does not entail a life-threatening risk, it will increase the adverse risk due to the associated unsteady gait, fall, fractures, and functional disability. The import factors in diagnosing sarcopenia are muscle mass and strength. The examination of muscle mass must be carried in the clinic. However, the loss of muscle mass can be improved by rehabilitation that can be performed in non-medical environments. Electronic impedance myography (EIM) can measure some parameters of muscles that have the correlations with muscle mass and strength. The goal of this study is to use machine learning algorithms to estimate the total mass of thigh muscles (MoTM) with the parameters of EIM and body information. We explored the seven major muscles of lower limbs. The feature selection methods, including recursive feature elimination (RFE) and feature combination, were used to select the optimal features based on the ridge regression (RR) and support vector regression (SVR) models. The optimal features were the resistance of rectus femoris normalized by the thigh circumference, phase of tibialis anterior combined with the gender, and body information, height, and weight. There were 96 subjects involved in this study. The performances of estimating the MoTM used the regression coefficient (r²) and root-mean-square error (RMSE), which were 0.800 and 0.929, and 1.432 kg and 0.980 kg for RR and SVR models, respectively. Thus, the proposed method could have the potential to support people examining their muscle mass in non-medical environments.

Sarcopenia, a major clinical problem in old age, potential causes, clinical consequences and therapeutic possibilities

Sarcopenia or degeneration of skeletal muscle tissue with aging, is responsible for functional de-cline and loss of independence in older adults. The purpose of this article is to review the current definitions of sarcopenia, its potential causes, clinical consequences and the potential for prop-hylactic and curative intervention. Sarcopenia is recognized as a major clinical problem for the elderly, and the research in this area is growing exponentially. One of the most important recent developments has been convergence in the operational definition of sarcopenia that combines muscle mass, strength and muscle function. In 2010, the European Working Group on Sarcopenia in Oder People (EWGSOP) published a definition of sarcopenia aimed at promoting progress in the identification and care of the elderly. In early 2018 (EWGSOP2) he met again to update the original definition to reflect the scientific and clinical evidence that has been built over the past decade. The cause of sarcopenia is considered to be multifactorial: hormonal changes, neurologi-cal decline, sedentary / immobilization for a long period, chronic diseases, obesity, all these fac-tors contribute to the onset of sarcopenia. Prophylactic or curative interventions are essentially aimed at nutrition and exercise. Although pharmaceutical agents are developed that target seve-ral biological pathways, proper nutrition and specific physical exercises remain the gold stan-dard for therapy. Through this review, we want to draw attention to the need to implement complex analyzes of the elderly patient, regardless of the acute problem with which he presents himself at the consultation. These analyses should contain tests, measurements, questionnaires that identify in time a possible musculoskeletal degeneration. The results did not show any sig-nificant difference between the perception of sarcopenia, the way of approaching it and the prophylactic or therapeutic treatment. We focused on this pathology because sarcopenia is rela-tively newly observed, defined, it is not fully investigated and a clinical skill has not been for-med for the evaluation of the elderly patient. Keywords: Skeletal muscle, elderly, sarcopenia, degeneration, exercises

The effect of sarcopenia on outcomes following orthopaedic surgery : a systematic review

AIMS

Sarcopenia is characterized by a generalized progressive loss of skeletal muscle mass, strength, and physical performance. This systematic review primarily evaluated the effects of sarcopenia on postoperative functional recovery and mortality in patients undergoing orthopaedic surgery, and secondarily assessed the methods used to diagnose and define sarcopenia in the orthopaedic literature.

METHODS

A systematic search was conducted in MEDLINE, EMBASE, and Google Scholar databases according to the Preferred Reporting Items for Systematic reviews and Meta-Analyses (PRISMA) guidelines. Studies involving sarcopenic patients who underwent defined orthopaedic surgery and recorded postoperative outcomes were included. The quality of the criteria by which a diagnosis of sarcopenia was made was evaluated. The quality of the publication was assessed using Newcastle-Ottawa Scale.

RESULTS

A total of 365 studies were identified and screened, 26 full-texts were reviewed, and 19 studies were included in the review. A total of 3,009 patients were included, of whom 2,146 (71%) were female and 863 (29%) were male. The mean age of the patients was 75.1 years (SD 7.1). Five studies included patients who underwent spinal surgery, 13 included hip or knee surgery, and one involved patients who underwent fixation of a distal radial fixation. The mean follow-up was 1.9 years (SD 1.9; 5 days to 5.6 years). There was wide heterogeneity in the measurement tools which were used and the parameters for the diagnosis of sarcopenia in the studies. Sarcopenia was associated with at least one deleterious effect on surgical outcomes in all 19 studies. The postoperative rate of mortality was reported in 11 studies (57.9%) and sarcopenia was associated with poorer survival in 73% (8/11) of these. The outcome was most commonly assessed using the Barthel Index (4/19), and sarcopenic patients recorded lower scores in 75% (3/4) of these. Sarcopenia was defined using the gold-standard three parameters (muscle strength, muscle quantity or quality, and muscle function) in four studies (21%), using two parameters in another four (21%) and one in the remaining 11 (58%). The methodological quality of the studies was moderate to high.

CONCLUSION

There is much heterogeneity in the reporting of the parameters which are used for the diagnosis of sarcopenia, and evaluating the outcome of orthopaedic surgery in sarcopenic patients. However, what data exist suggest that sarcopenia impairs recovery and increases postoperative mortality, especially in patients undergoing emergency surgery. Further research is required to develop processes that allow the accurate diagnosis of sarcopenia in orthopaedics, which may facilitate targeted pre- and postoperative interventions that would improve outcomes. Cite this article: Bone Joint J 2022;104-B(3):321-330.

Establishment and Validation of Pre-Therapy Cervical Vertebrae Muscle Quantification as a Prognostic Marker of Sarcopenia in Patients With Head and Neck Cancer

Background

Sarcopenia is prognostic for survival in patients with head and neck cancer (HNC). However, identification of this high-risk feature remains challenging without computed tomography (CT) imaging of the abdomen or thorax. Herein, we establish sarcopenia thresholds at the C3 level and determine if C3 sarcopenia is associated with survival in patients with HNC.

Methods

This retrospective cohort study was conducted in consecutive patients with a squamous cell carcinoma of the head and neck with cross-sectional abdominal or neck imaging within 60 days prior to treatment. Measurement of cross-sectional muscle area at L3 and C3 levels was performed from CT imaging. Primary study outcome was overall survival.

Results

Skeletal muscle area at C3 was strongly correlated with the L3 level in both men (n = 188; r = 0.77; p < 0.001) and women (n = 65; r = 0.80; p < 0.001), and C3 sarcopenia thresholds of 14.0 cm²/m² (men) and 11.1 cm²/m² (women) were best predictive of L3 sarcopenia thresholds. Applying these C3 thresholds to a cohort of patients with neck imaging alone revealed that C3 sarcopenia was independently associated with reduced overall survival in men (HR = 2.63; 95% CI, 1.79, 3.85) but not women (HR = 1.18, 95% CI, 0.76, 1.85).

Conclusions

This study identifies sarcopenia thresholds at the C3 level that best predict L3 sarcopenia in men and women. In HNC, C3-defined sarcopenia is associated with poor survival outcomes in men, but not women, suggesting sarcopenia may differentially affect men and women with HNC.

Height-adjusted lean body mass and its associations with physical activity and kidney function in pediatric kidney transplantation

BACKGROUND

Although LBM is positively associated with health outcomes, studies assessing determinants for the accrual of ht-LBM, such as physical activity, are limited. This study aimed to assess ht-LBM levels in pediatric kidney transplant recipients and test its association with baseline and contemporaneous variables, including physical activity.

METHODS

A retrospective cross-sectional review was performed on 46 pediatric kidney transplant recipients, and a longitudinal review was performed on a subset of recipients with serial post-transplant (n = 21) and pre/post-transplant (n = 11) ht-LBM measurements. Ht-LBM measurements were obtained using DXA scans.

RESULTS

This cohort was 16.0 (IQR 12.3, 17.7) years old, 56.5% male and 46 ± 45 months post-transplant with a mean ht-LBM of 15.1 ± 2.5 kg/m² . A median ht-LBM increase of 1.6 kg/m² (IQR - 0.1, 2.6 kg/m² ; p < .01) was observed, over 29.2 ± 12.0 months from the earliest post-transplant scan obtained at 46 ± 25 months post-transplant until the most recent post-transplant scan. A 1.7 ± 1.4 kg/m² (p < .01) increase was observed between pre- and post-transplant DXA scans which were taken at 12 ± 11 months pre-transplant and 13 ± 6 months post-transplant, respectively. In separate adjusted models, lower physical activity questionnaire scores (n = 17, beta = 1.55, p = .02), faster rate of estimated glomerular filtration rate decline (beta = 0.05, p < .048) adjusted for annualized change in BSA, and younger age at scan (beta = 0.32, p < .01) were each significant predictors of lower ht-LBM.

CONCLUSIONS

Physical activity and kidney function may influence ht-LBM in the pediatric kidney transplant population.

Comparison of quadriceps muscle size and quality in adults with cystic fibrosis with different severities of cystic fibrosis transmembrane conductance regulator protein dysfunction

Background

Cystic fibrosis (CF) is characterized by CF transmembrane conductance regulator (CFTR) dysfunction. CFTR protein is expressed in human skeletal muscle; however, its impact on skeletal muscle is unknown. The objectives of this study were to compare quadriceps muscle size and quality between adults with various severities of CFTR protein dysfunction.

Methods

We conducted a prospective, cross-sectional study comparing 34 adults with severe versus 18 with mild CFTR protein dysfunction, recruited from a specialized CF centre. Ultrasound images of rectus femoris cross-sectional area (RF-CSA) and quadriceps layer thickness for muscle size, and rectus femoris echogenicity (RF-ECHO) (muscle quality) were obtained. Multivariable linear regression models were developed using purposeful selection technique.

Results

People with severe CFTR protein dysfunction had larger RF-CSA by 3.22 cm², 95% CI (1.03, 5.41) cm², p=.0049], after adjusting for oral corticosteroid use and Pseudomonas aeruginosa colonization. However, a sensitivity analysis indicated that the result was influenced by the specific confounders being adjusted for in the model. We did not find any significant differences in quadriceps layer thickness or RF-ECHO between the two groups.

Conclusion

We found no differential impact of the extent of diminished CFTR protein activity on quadriceps muscle size or quality in our study cohort. Based on these findings, CFTR mutation status cannot be used differentiate leg muscle size or quality in people with CF.

Higher Body Fat in Children and Adolescents With Type 1 Diabetes-A Systematic Review and Meta-Analysis

AIMS

Higher prevalence of overweight and obesity in children and adolescents with type 1 diabetes (T1D) suggests alterations are required in body composition. However, differences in body composition between children with T1D and typically developing children (TDC) have not been synthesized using meta-analysis. Therefore, we conducted a systematic review and meta-analysis to compare body composition between children with T1D and TDC, and to explore the role of disease and non-disease related factors in potential body composition differences.

METHODS

Studies were performed comparing dual-energy x-ray absorptiometry-acquired total body fat and lean mass, absolute (kg) and relative (%) values, between children with T1D and TDC. We reported mean differences with 95% confidence intervals (CI) from meta-analysis and relative between-group %-differences. We used meta-regression to explore the role of sex, age, height, body mass, body mass index, Hemoglobin A1c, age of onset, disease duration, and insulin dosage in the potential body composition differences between children with T1D and TDC, and subgroup analysis to explore the role of geographic regions (p < 0.05).

RESULTS

We included 24 studies (1,017 children with T1D, 1,045 TDC) in the meta-analysis. Children with T1D had 1.2 kg more fat mass (kg) (95%CI 0.3 to 2.1; %-difference = 9.3%), 2.3% higher body fat % (0.3-4.4; 9.0%), but not in lean mass outcomes. Age of onset (β = -2.3, -3.5 to -1.0) and insulin dosage (18.0, 3.5-32.6) were negatively and positively associated with body fat % mean difference, respectively. Subgroup analysis suggested differences among geographic regions in body fat % (p < 0.05), with greater differences in body fat % from Europe and the Middle East.

CONCLUSION

This meta-analysis indicated 9% higher body fat in children with T1D. Earlier diabetes onset and higher daily insulin dosage were associated with body fat % difference between children with T1D and TDC. Children with T1D from Europe and the Middle East may be more likely to have higher body fat %. More attention in diabetes research and care toward body composition in children with T1D is needed to prevent the early development of higher body fat, and to minimize the cardiovascular disease risk and skeletal deficits associated with higher body fat.

Does sarcopenia affect outcomes in pediatric surgical patients? A scoping review

OBJECTIVE

Adults with sarcopenia have a greater risk of postoperative complications, a higher rate of ICU admission, and an increased length of hospital stay. Few studies have explored the prevalence or importance of sarcopenia in the pediatric population. This study reviews the published literature on sarcopenia in the pediatric population, including pediatric surgery.

METHODS

Original studies related to sarcopenia in children were identified using the Preferred Reporting Items for Systematic Reviews and Meta-Analyses Extension for Scoping Reviews (PRISMA-ScR) guidelines and the PubMed database.

RESULTS

A total of 390 articles were screened, with 28 meeting inclusion criteria. Twenty (71%) studies provided a means to define abnormal and 18 studies (64%) showed that a specific disease process could impact lean muscle mass in children. Only 4 (14%) studies associated the change in muscle mass with an outcome. Two studies investigated sarcopenia and outcomes in the pediatric surgical patient and demonstrated associations with worse outcomes.

CONCLUSION

Despite studies showing an association between sarcopenia and negative outcomes in the adult surgical population, there remains a paucity of evidence regarding the impact of sarcopenia on the pediatric population. Future studies are needed to ascertain the relationship between muscle mass and outcomes in pediatric surgical patients.

Peripheral Quantitative Computed Tomography Derived Muscle Density Is Associated With Physical Performance in Older Adults

PURPOSE

The assessment of body composition is an integral part in diagnosing sarcopenia. The purpose of this study was to determine the relationships between peripheral quantitative computed tomography (pQCT)-derived measures of body composition and measures of physical performance in older adults.

METHODS

Muscle density, muscle area, and fat area of 168 patients aged 65 years and older (76.3±6.5) were measured with pQCT at the distal forearm additionally to clinical assessment consisting of medical history, physical examination and physical assessment including hand grip strength, gait speed and chair rise tests. Regression analyses assessed associations between patients' physical performance and pQCT derived data.

RESULTS

Among the three pQCT parameters, especially muscle density was significantly correlated with all of the three measures of physical performance even after adjusting for sex, age, BMI, vitamin D serum level and the level of physical activity. The same analysis for muscle area achieved significance level only for handgrip strength but not for gait speed nor for chair rise time. Fat area was significantly correlated only with gait speed after adjusting for sex and age. The association of muscle density with physical performance held up in an additional subanalysis stratified by body mass index.

CONCLUSION

Muscle density, a proxy for muscle fat infiltration, seems to be better than muscle area or fat area at assessing muscle quality and physical performance in older adults. This association seems to be independent of the body mass index.

Relevance of nutritional assessment and treatment to counteract cardiac cachexia and sarcopenia in chronic heart failure

Chronic heart failure (CHF) is frequently associated with the involuntary loss of body weight and muscle wasting, which can determine the course of the disease and its prognosis. While there is no gold standard malnutrition screening tool for their detection in the CHF population, several bioelectrical and imaging methods have been used to assess body composition in these patients (such as Dual Energy X-Ray Absorptiometry and muscle ultrasound, among other techniques). In addition, numerous nutritional biomarkers have been found to be useful in the determination of the nutritional status. Nutritional considerations include the slow and progressive supply of nutrients, avoiding high volumes, which could ultimately lead to refeeding syndrome and worsen the clinical picture. If oral feeding is insufficient, hypercaloric and hyperproteic supplementation should be considered. β-Hydroxy-β-methylbutyrate and omega-3 polyunsaturated fatty acid administration prove to be beneficial in certain patients with CHF, and several interventional studies with micronutrient supplementation have also described their possible role in these subjects. Taking into account that CHF is sometimes associated with gastrointestinal dysfunction, parenteral nutritional support may be required in selected cases. In addition, potential therapeutic options regarding nutritional state and muscle wasting have also been tested in clinical studies. This review summarises the scientific evidence that demonstrates the necessity to carry out a careful nutritional evaluation and nutritional treatment to prevent or improve cardiac cachexia and sarcopenia in CHF, as well as improve its course.

Skeletal Muscle Quality: A Biomarker for Assessing Physical Performance Capabilities in Young Populations

Muscle quality (MQ), defined as the amount of strength and/or power per unit of muscle mass, is a novel index of functional capacity that is increasingly relied upon as a critical biomarker of muscle health in low functioning aging and pathophysiological adult populations. Understanding the phenotypical attributes of MQ and how to use it as an assessment tool to explore the efficacy of resistance exercise training interventions that prioritize functional enhancement over increases in muscle size may have implications for populations beyond compromised adults, including healthy young adults who routinely perform physically demanding tasks for competitive or occupational purposes. However, MQ has received far less attention in healthy young populations than it has in compromised adults. Researchers and practitioners continue to rely upon static measures of lean mass or isolated measures of strength and power, rather than using MQ, to assess integrated functional responses to resistance exercise training and physical stress. Therefore, this review will critically examine MQ and the evidence base to establish this metric as a practical and important biomarker for functional capacity and performance in healthy, young populations. Interventions that enhance MQ, such as high-intensity stretch shortening contraction resistance exercise training, will be highlighted. Finally, we will explore the potential to leverage MQ as a practical assessment tool to evaluate function and enhance performance in young populations in non-traditional research settings.

Effects of multimodal prehabilitation on muscle size, myosteatosis, and dietary intake of surgical patients with lung cancer - a randomized feasibility study

Many patients with lung cancer undergo surgery, which can increase the risk for muscle loss, leading to worsened outcomes. A multimodal prehabilitation intervention integrating dietary and muscle assessment may help clinicians better understand changes in these outcomes. This pilot assessed feasibility of multimodal prehabilitation in early-stage surgical lung cancer patients and explored relationships between body composition, muscle characteristics and dietary intake, as well as muscle changes due to prehabilitation. Patients were randomized to one of two groups: multimodal prehabilitation including nutritional supplements (fish oil with vitamin D3 + whey protein with leucine), exercise and relaxation, or standard of care. Physical function, dietary intake and muscle were evaluated at 0 and 4 weeks pre-operatively. Of 87 patients assessed for eligibility, 34 (39%) were randomized and 3 (9%) were lost to follow-up. Median age was 69 years and baseline protein intake was 1.0 g/kg/d. Adherence to exercise (86%) and supplements was high (93%); 3 patients (16%) reported side effects. Supplements significantly increased protein, omega-3 fatty acid, leucine and vitamin D intake. There were no significant changes in muscle characteristics. Multimodal prehabilitation with dietary and muscle analyses proved to be feasible. An adequately powered randomized controlled trial is warranted. ClinicalTrials.gov registration no: NCT04610606. Novelty: • Multimodal prehabilitation incorporating dietary assessment and muscle analysis is feasible for early-stage surgical lung cancer patients. • An adequately powered randomized controlled trial is warranted to further explore functional and post-operative outcomes.

The Assessment of Skeletal Muscle and Cortical Bone by Second-generation HR-pQCT at the Tibial Midshaft

BACKGROUND

Peripheral quantitative computed tomography (pQCT) is the current densitometric gold-standard for assessing skeletal muscle at the 66% proximal tibia site. High resolution peripheral quantitative computed tomography (HR-pQCT) is a leading technology for quantifying bone microarchitecture at the distal extremities, and with the second-generation HR-pQCT it is possible to measure proximal limb sites. Therefore, the objectives of this study were to: (1) assess the feasibility of using HR-pQCT to assess skeletal muscle parameters at the 66% proximal tibia site, and (2) test HR-pQCT skeletal muscle measurement reproducibility at this site.

METHODS

Adult participants (9 males; 7 females; ages 31-75) received 1 pQCT scan and 2 HR-pQCT scans at the 66% proximal site of the nondominant tibia. Participants were repositioned between HR-pQCT scans to test reproducibility. HR-pQCT and pQCT scans were analyzed to quantify muscle cross-sectional area (CSA) and muscle density. Coefficients of determination and Bland-Altman plots compared muscle parameters between pQCT and HR-pQCT. For short-term reproducibility, root-mean-square of coefficient of variance and least significant change were calculated.

RESULTS

HR-pQCT and pQCT measured muscle density and muscle CSA were positively correlated (R² = 0.66, R² = 0.95, p < 0.001, respectively). Muscle density was equivalent between HR-pQCT and pQCT; however, there was systematic and directional bias for muscle CSA, such that muscle CSA was 11% lower with HR-pQCT and bias increased with larger muscle CSA. Root-mean-square of coefficient of variance was 0.67% and 0.92% for HR-pQCT measured muscle density and muscle CSA, respectively, while least significant change was 1.4 mg/cm³ and 174.0 mm² for muscle density and muscle CSA, respectively.

CONCLUSION

HR-pQCT is capable of assessing skeletal muscle at the 66% site of the tibia with good precision. Measures of muscle density are comparable between HR-pQCT and pQCT.

Sarcopenia is a Predictor for Adverse Clinical Outcome in Pediatric Inflammatory Bowel Disease

OBJECTIVES

Inflammatory bowel disease (IBD) has a high impact on nutritional status. Sarcopenia is related to higher risk of surgery and rescue therapy in adults with IBD; however, comparable data in pediatric populations are scarce. We evaluated muscle mass as a predictor of disease outcome in pediatric IBD.

METHODS

All pediatric IBD patients who underwent magnetic resonance enterography (MRE) during 2008 to 2019 were included. Muscle mass was assessed by measuring the area of the psoas muscle at the upper level of L3 on MRE. The psoas area divided by the body surface area (BSA) yielded the psoas index. Clinical and radiological data, including disease location, activity, course, and medications were documented. The control group included non-IBD children who underwent an MR imaging study.

RESULTS

We enrolled 101 IBD patients, 69 (68.3%) with Crohn disease (CD) and 32 (31.7%) with ulcerative colitis (UC) (mean age 15.03 ± 3.27 years). The psoas index was significantly lower in the IBD patients compared with the 87 controls (326 vs 528, respectively, P < 0.001). Patients with a psoas index in the lowest quartile had significantly higher risk for biologic therapy (multivariate analysis, hazard ratio [HR] = 12.1, P = 0.046) and disease exacerbation (HR = 9, P = 0.047) independently of body mass index, compared with patients with a psoas index in the uppermost quartile.

CONCLUSIONS

Sarcopenia correlates with the radiological severity of pediatric IBD and serves as a predictor for adverse clinical disease outcome. Muscle mass measurement in MRE studies may serve as a possible marker for disease outcome in this population.