Skeletal muscle cutoff values for sarcopenia diagnosis using T10 to L5 measurements in a healthy US population

Quantification of Skeletal Muscle at the First Lumbar Level for Prognosis in Amyotrophic Lateral Sclerosis

BACKGROUND

Skeletal muscle parameters at the first lumbar vertebra (L1) level on computed tomography (CT) are common indicators for muscle mass. However, their relationship with the severity and prognosis of amyotrophic lateral sclerosis (ALS) patients remains unclear.

METHODS

This cohort study included ALS patients who underwent chest CT scans between January 2018 and January 2022 and healthy controls (HCs) matched for gender and age. Overall survival (OS) was determined from the date of chest CT to death, tracheal intubation or 1 January 2024. Using ImageJ software, skeletal muscle area and density (L1 SMA/SMD), skeletal muscle index (L1 SMI), paraspinal muscle area and density (L1 PMA/PMD) and subcutaneous fat area and density (L1 SFA/SFD) at L1 were quantified. The relationships between the quantified muscle parameters and both King's clinical stages and the Revised ALS Functional Rating Scale (ALSFRS-R) were analysed. The Cox proportional hazard model was used to evaluate the hazard ratio (HR) of skeletal muscle parameters as risk factors for outcome events, and to construct a nomogram.

RESULTS

Muscle parameters in ALS patients (n = 102; 36.27% female; mean age, 60.85 ± 10.58 years) were significantly lower compared with HCs (p < 0.001). L1 SMD (p = 0.047) and L1 PMD (p = 0.003) both differed significantly across the King's clinical stages. ALSFRS-R scores correlated with L1 SMA (r = 0.35, p < 0.001), L1 SMI (r = 0.34, p < 0.001), L1 PMA (r = 0.27, p = 0.007) and L1 PMD (r = 0.27, p = 0.007). Multivariate Cox regression analysis revealed that L1 SMA (HR = 0.96, 95% confidence interval [CI] = 0.94-0.98, p = 0.001), L1 SMD (HR = 0.92, 95% CI = 0.88-0.96, p < 0.001) and L1 PMA (HR = 1.06, 95% CI = 1.01-1.11, p = 0.022) significantly influenced ALS survival, with area under the curves (AUCs) of 0.687 and 0.851 for 1- and 3-year OS prediction. The consistency index (C-index) for the nomogram was 0.72 (95% CI = 0.641-0.793).

CONCLUSIONS

Skeletal muscle parameters at L1 level on CT are significantly associated with clinical severity and prognosis in ALS.

TRIAL REGISTRATION

Chinese Clinical Trial Registration Center: ChiCTR230078702.

Psoas muscle density predicts elective colorectal surgical outcomes more accurately than psoas muscle area or indexed area

BACKGROUND

CT measurements of psoas muscle density (PMD) and area (PMA) (with or without indexing to height-squared or body-surface-area) are used interchangeably as sarcopenia measures - it is unknown which best correlates with surgical risk.

OBJECTIVES

1.Determine the correlation between psoas muscle density, area, and indexed area; 2.Identify which psoas measures most strongly associated with surgical outcomes DESIGN: The University Hospital Geelong Colorectal database included all patients who underwent elective colorectal surgery from 2007 to 2014 (minimum five-years follow-up). Pre-operative CT scans were reviewed, psoas measures correlated with each other and with outcomes.

SETTING

University Hospital Geelong is a regional referral hospital in Victoria, Australia.

PARTICIPANTS

This database listed 552 patients, 120 were excluded as pre-operative CT-films were not accessible, leaving 432 patients included.

EXPOSURE

Psoas muscle density, area, and area indexed by height-squared and body-surface-area.

MEASUREMENTS

Pearson correlations investigated correlations between psoas muscle measures. Logistic regression and ROC-analysis investigated each psoas measures association with peri‑operative morbidity. Kaplan-Meier survival-analysis investigated the association of each psoas measure with long-term survival.

RESULTS

Mean age was 70.4 years, 41 % were female. Psoas muscle density correlated poorly with area (R2=0.15). Unindexed psoas muscle area correlated well with area indexed by height-squared (R2=0.950) and body-surface-area (R2=0.938). Long-term survival was associated with psoas muscle density (HR1.515(95 %CI 1.062-2.161)) and area (HR1.886(95 %CI 1.322-2.692)). Increasing psoas muscle density (reduced sarcopenia) was associated with decreased major-complications (OR0.963(95 %CI 0.938-0.989)) and peri‑operative mortality (OR0.903(95 %CI 0.847-0.962)), with ROC-curve AUC=0.829 indicating an accurate test. There was no association between psoas muscle area and major-complications (OR1.000(95 %CI 1.000-1.000)), nor peri‑operative mortality (OR1.000(95 %CI 0.999-1.001)), with ROC-curves AUC=0.507-0.521. Indexed area measures were not associated with outcomes.

CONCLUSIONS

Psoas muscle density and area did not correlate. Both were associated with long-term survival, but only density was associated major-complications and mortality. Indexing removed the correlation of area with long-term survival.

The extent of Skeletal muscle wasting in prolonged critical illness and its association with survival: insights from a retrospective single-center study

OBJECTIVE

Muscle wasting in critically ill patients, particularly those with prolonged hospitalization, poses a significant challenge to recovery and long-term outcomes. The aim of this study was to characterize long-term muscle wasting trajectories in ICU patients with acute respiratory distress syndrome (ARDS) due to COVID-19 and acute pancreatitis (AP), to evaluate correlations between muscle wasting and patient outcomes, and to identify clinically feasible thresholds that have the potential to enhance patient care strategies.

MATERIALS AND METHODS

A collective of 154 ICU patients (100 AP and 54 COVID-19 ARDS) with a minimum ICU stay of 10 days and at least three abdominal CT scans were retrospectively analyzed. AI-driven segmentation of CT scans quantified changes in psoas muscle area (PMA). A mixed model analysis was used to assess the correlation between mortality and muscle wasting, Cox regression was applied to identify potential predictors of survival. Muscle loss rates, survival thresholds and outcome correlations were assessed using Kaplan-Meier and receiver operating characteristic (ROC) analyses.

RESULTS

Muscle loss in ICU patients was most pronounced in the first two weeks, peaking at -2.42% and - 2.39% psoas muscle area (PMA) loss per day in weeks 1 and 2, respectively, followed by a progressive decline. The median total PMA loss was 48.3%, with significantly greater losses in non-survivors. Mixed model analysis confirmed correlation of muscle wasting with mortality. Cox regression identified visceral adipose tissue (VAT), sequential organ failure assessment (SOFA) score and muscle wasting as significant risk factors, while increased skeletal muscle area (SMA) was protective. ROC and Kaplan-Meier analyses showed strong correlations between PMA loss thresholds and survival, with daily loss > 4% predicting the worst survival (39.7%).

CONCLUSIONS

To our knowledge, This is the first study to highlight the substantial progression of muscle wasting in prolonged hospitalized ICU patients. The mortality-related thresholds for muscle wasting rates identified in this study may provide a basis for clinical risk stratification. Future research should validate these findings in larger cohorts and explore strategies to mitigate muscle loss.

CLINICAL TRIAL NUMBER

Not applicable.

Impact of Sarcopenia on Outcomes Following Endovascular Treatment of Patients with Pelvic Venous Insufficiency

PURPOSE

To investigate the influence of sarcopenia on the outcomes of endovascular treatment in patients with pelvic venous insufficiency (PVI).

MATERIAL AND METHODS

A retrospective analysis was conducted on 62 female patients who underwent endovascular treatment for PVI between January 2012 and July 2020. The patients were evaluated using the Visual Analog Scale (VAS) for chronic pelvic pain, both before treatment and three months post-treatment. A successful treatment outcome was defined as a reduction in pelvic pain by 50% or more. Sarcopenia was diagnosed based on the skeletal muscle mass index (SMI) of the patients.

RESULTS

Sarcopenia was present in 20 (32.3%) patients. There was no significant difference in preprocedural VAS scores between sarcopenic and non-sarcopenic patients (36.2 ± 16.9 vs. 34.9 ± 16.1, p = 0.781). However, non-sarcopenic patients achieved a significantly greater reduction in VAS scores post-treatment (67.6 ± 22.4% vs. 53.1 ± 24.4%, p = 0.025). A moderate negative correlation was observed between sarcopenia and successful treatment outcomes (r = -0.365, p = 0.004).

CONCLUSION

Sarcopenia negatively impacts the effectiveness of endovascular treatment in patients with PVI.

Defining Reference Values for Skeletal Muscle Metrics on Abdominal CT Using Data From Healthy Young Adult Populations: A Systematic Review and Meta-Analysis

BACKGROUND. CT muscle metrics hold promise for opportunistic sarcopenia screening and individualized clinical risk stratification, but reference values applicable across broad populations are lacking. OBJECTIVE. To estimate reference cutoff values for CT skeletal muscle metrics using data from populations of healthy young adults. EVIDENCE ACQUISITION. The PubMed, Embase, Cochrane Library, Web of Science, and Scopus databases were searched through January 1, 2025 for studies reporting skeletal muscle index (SMI) and/or skeletal muscle density (SMD) on CT at the L3 vertebral level in healthy young adults (age range, 18-45 years). For SMI and SMD in both men and women, a random effects meta-analysis was used to estimate interstudy SD (as a measure of variance among studies) and mean values for a theoretic global population of healthy young adults. Presence of significant heterogeneity among individual study means was assessed using the Q statistic. Cutoff values for the theoretic global population corresponding with a T-score of -2 (i.e., values ≥ 2 SDs below the population's mean value) were calculated, incorporating the meta-analysis results and pooled intrastudy variance. EVIDENCE SYNTHESIS. The meta-analysis included 14 studies (16,958 individuals; 11,819 men, 5139 women) reporting SMI, of which seven studies (11,175 individuals; 8372 men, 2803 women) also reported SMD. The estimated global mean value for SMI was 54.6 in men and 42.4 in women and for SMD was 47.4 HU in men and 43.6 HU in women. The interstudy SD for SMI was 5.4 in men and 4.3 in women and for SMD was 1.9 in men versus 3.2 in women; significant heterogeneity was present among individual study means for both SMI and SMD in both men and women (all p<.001). The cutoff value corresponding with a T-score of -2 for SMI was 36.3 in men and 27.5 in women and for SMD was 36.4 HU in men and 28.1 HU in women. CONCLUSION. This meta-analysis of studies performed in healthy young adults provides reference mean values and standardized cutoffs analogous to a T-score of -2 for SMI and SMD at the L3 level on abdominal CT. CLINICAL IMPACT. These results can aid opportunistic screening for sarcopenia.

Normative data for age-specific skeletal muscle area based on computed tomography in Korean population

BACKGROUND

Sarcopenia, a progressive loss of muscle mass and function, increases health risks in older adults, especially in rapidly ageing populations like Korea. Computed tomography (CT) imaging at the third lumbar vertebra (L3) level is a gold standard for assessing skeletal muscle area (SMA) and indices (SMIs), yet age- and sex-specific reference values are limited. This multicentre study aimed to establish these values for improved sarcopenia diagnosis.

METHODS

We conducted a retrospective study with 2637 healthy Korean adults (1366 men, 1271 women) aged 20 and older, using abdominal CT scans from routine health check-ups at four centres. SMA and SMIs were measured at L3, and T-scores were calculated by comparing participants' values with a healthy young reference group (ages 20-39). Sarcopenia was classified into Classes I and II using standardised cutoffs.

RESULTS

An age-related SMA decline was observed in both sexes, with a more significant reduction in men. Sarcopenia prevalence was higher in men based on the SMA index, while SMA/body mass index (BMI) was more sensitive in women. Class I sarcopenia ranged from 10.1% to 21.3% in men and 10.6% to 23.6% in women, with Class II prevalence between 1.0% and 5.5% in men and 1.3% and 8.3% in women.

CONCLUSION

This study establishes CT-based reference values for SMA and SMIs, supporting early sarcopenia detection, with the SMA/BMI index proving valuable for both men and women.

Validating a Practical Correction for Intravenous Contrast on Computed Tomography-Based Muscle Density

OBJECTIVE

Computed tomography (CT) measured muscle density is prognostic of health outcomes. However, the use of intravenous contrast obscures prognoses by artificially increasing CT muscle density. We previously established a correction to equalize contrast and noncontrast muscle density measurements. While this correction was validated internally, the objective of this study was to obtain external validation using different patient cohorts, muscle regions, and CT series.

METHODS

CT images from 109 patients with kidney tumors who received abdominal CT scans with a multiphase intravenous contrast protocol were analyzed. Paraspinal muscle density measurements taken during noncontrast, venous phase, and delayed phase contrast scans were collected. An a priori correction of -7.5 Hounsfield units (HU) was applied to muscle measurements. Equivalence testing was utilized to determine statistical similarity.

RESULTS

In the sample of 109 patients (mean age: 63 years [SD: 14.3]; 41.3% female), densities in smaller regions of interest within the paraspinal muscles and the entire paraspinal muscle density (PS) in venous and delayed phase contrast scans were higher than in noncontrast. Equivalence testing showed that average corrected contrast and noncontrast muscle densities were within 3 HU for both muscle measures for the total patient sample, and for a majority of male and female subsamples. The correction is suitable for regions of interests of venous contrast (90% CI: -1.90, -0.69 HU) and delayed contrast scans (90% CI: 0.075, 1.29 HU) and within the PS measures of venous contrast (90% CI: -2.04, -0.94 HU) and delayed contrast scans (90% CI: -0.11, 0.89 HU).

CONCLUSIONS

The previously established correction for contrast of -7.5 HU was applied in a new patient population, axial muscle region, muscle measurement size, and expanded on previously studied contrast phases. The correction produced contrast-corrected muscle densities that were statistically equivalent to noncontrast muscle densities. The simplicity of the correction gives clinicians a tool that seamlessly integrates into practice or research to improve harmonization of data between contrast and noncontrast scans.

Reliability and Diagnostic Accuracy of EOS Full-Body Upright Imaging for Sarcopenia: A Retrospective Study Comparing Thigh Muscle to CT-Derived Psoas Muscle Measurements

BACKGROUND

Sarcopenia increases postoperative complication and mortality rates in elderly patients. Although measurement of the psoas muscle area on computed tomography (CT) scans is traditionally used to diagnose sarcopenia, CT is not routine in orthopaedic practice and causes unnecessary radiation exposure. EOS, a low-dose full-body imaging modality, captures musculoskeletal structures in an upright position, offering an alternative for sarcopenia diagnosis.

METHODS

Patients ≥18 years of age were included in this retrospective study if they had undergone non-contrast CT spine and EOS imaging between May 2022 and May 2024. Psoas muscle measurements at L3 and L4 were made using non-contrast CT scans, while thigh muscle measurements were obtained with EOS imaging. Inter- and intra-rater reliabilities were assessed using intraclass correlation coefficients (ICCs). Predicted probabilities for L4-psoas sarcopenia were determined through logistic regression, controlling for demographic covariates and validated with an 80% to 20% train-validate split. Sarcopenia cutoffs for anteroposterior (AP) thigh thickness and lateral (LAT) quadriceps thickness were determined with use of the Youden index.

RESULTS

Sarcopenia was identified in 23.1% of 134 patients (85 female and 49 male; 121 White, 7 Black, and 6 Hispanic) on the basis of L4-psoas muscle index thresholds. EOS and CT measurements showed excellent ICCs (≥0.90). Multivariable regressions identified AP thigh thickness and LAT quadriceps thickness as significant predictors of psoas area and L4-psoas sarcopenia. The area under the receiver operating characteristic curve for identifying L4-psoas sarcopenia was 0.85 for AP thigh thickness and 0.77 for LAT quadriceps thickness. Cutoffs were 12.47 cm (males) and 10.68 cm (females) for AP thigh thickness, and 3.23 cm (males) and 2.20 cm (females) for LAT quadriceps thickness. In the validation cohort of 27 patients, the AP thigh thickness model showed 0.94 sensitivity and 0.89 specificity, while the LAT quadriceps thickness model showed 0.70 sensitivity and 1.00 specificity. Applying these cutoffs to the entire data set showed that 66.7% of males and 75.0% of females with measurements below both cutoffs had sarcopenia.

CONCLUSIONS

EOS is a reliable alternative to CT for muscle mass assessment and sarcopenia diagnosis. EOS may be a valuable tool for assessing sarcopenia without a CT scan, as thigh muscle measurements via EOS correlate well with CT-derived psoas measurements. This imaging modality aids in early sarcopenia diagnosis, potentially enhancing preoperative planning and reducing radiation exposure, unnecessary costs, and resource utilization.

LEVEL OF EVIDENCE

Prognostic Level III. See Instructions for Authors for a complete description of levels of evidence.

Association between sarcopenia and intervertebral disc degeneration: A bidirectional two-sample Mendelian randomization

BackgroundSarcopenia (SP) and Intervertebral Disc Degeneration (IVDD) are common age-related diseases that significantly affect the physical and mental health of patients. A substantial body of evidence suggests a potential association between SP and IVDD. However, the causal relationship between SP and IVDD remains uncertain.ObjectivesThis study aimed to determine whether the association between SP and IVDD is causal by employing Mendelian randomization (MR) analysis.MethodsGenome-wide association study (GWAS) data related to SP (measured by muscle lean mass, left- and right-hand grip strength, and walking speed) and IVDD were obtained from the UK Biobank and FinnGen. To investigate the causal relationship between SP and IVDD, three MR analysis methods were employed, primarily focusing on the Inverse-Variance Weighted (IVW) approach. The robustness of causal effects was ensured through multiple methods: Instrumental Variables (IVs) were evaluated using F-values; heterogeneity was assessed using Cochran's Q; horizontal pleiotropy was evaluated using MR Egger regression; and outliers was detected using MR-PRESSO and the leave-one-out method.ResultsThe analysis indicates a potential causal relationship between appendicular lean mass (ALM) and the risk of IVDD (OR = 0.89, 95% CI: 0.809-0.98; P < 0.05). Similarly, left-hand grip strength shows a potential causal relationship with IVDD risk (OR = 1.52, 95% CI:1.08-2.14; P < 0.05), as does right-hand grip strength (OR = 1.50, 95% CI:1.09-2.07; P < 0.05). Additionally, a potential causal relationship is observed between IVDD and walking speed (OR = 0.99, 95% CI:0.97-1.00; P < 0.05).ConclusionThe findings suggest that ALM may serve as a protective factor against IVDD, while left- and right-hand grip strength may be risk factors for the development of IVDD. Furthermore, IVDD appears to be a risk factor associated with reduced walking speed. Further research is necessary to elucidate the underlying mechanisms of these associations.

Sarcopenia in Patients with Chronic Thromboembolic Pulmonary Hypertension

BACKGROUND

Sarcopenia, or loss of skeletal muscle mass, has been associated with poor outcomes (e.g., functional decline, increased mortality, and low quality of life), but its role in CTEPH remains unclear. The psoas muscle index (PMI) is a validated measure of sarcopenia. We investigated the incidence of sarcopenia using PMI in CTEPH.

METHODS

Retrospective analysis of a single-center cohort of patients with CTEPH with an available computed tomography of the abdomen and pelvis (CTAP). PMI was measured at the L3 level of the CTAP and was then calculated using the formula (left psoas area + right psoas area/height2). Patients in the first quartile of PMI were classified as sarcopenic.

RESULTS

We reviewed 558 patients with CTEPH, and 97 patients had an available CTAP before intervention. Sarcopenia was identified in 26 (24.8%) of the patients and was associated with worse baseline functional status (p = 0.008), higher mean pulmonary artery pressure (48 vs. 39 mmHg; p = 0.002), and higher pulmonary vascular resistance (9.9 vs. 6.8 WU; p = 0.013). Post-PTE, patients with sarcopenia exhibited longer intensive care unit (ICU) (9 vs. 4 days, p < 0.001) and overall hospital stays (24 vs. 11 days, p < 0.001), despite similar post-operative hemodynamics achieved compared to non-sarcopenic patients.

CONCLUSIONS

CTEPH patients with sarcopenia have worse baseline functional class and hemodynamics. For those with sarcopenia requiring surgery, there is longer ICU and total hospitalization stays, but they achieve significant functional improvements and hemodynamics comparable to that of non-sarcopenic patients. Hence, the risk of longer perioperative hospitalization days is justified by the longer-term benefit of hemodynamic improvement. The use of PMI as part of routine pre-operative assessments could improve clinical decision-making in CTEPH patients undergoing surgical or medical intervention.

A comparison between radiomic biological age and chronological age in estimating kidney function

Accurate kidney function estimation hinges on essential markers of age and body size. The relative benefit of both markers has been debated with the emerging biological age and novel body size descriptors. We used radiomic biomarkers of age-related changes in body composition to construct new biological age indices as covariates of kidney function. A retrospective cohort of hospitalized patients with plasma concentrations of aminoglycosides and computed tomography images were evaluated. Aminoglycoside clearance served as a kidney function surrogate. A population pharmacokinetic model was constructed to determine whether biological age indices improved aminoglycoside clearance estimation compared to chronological age. The final dataset included 156 patients (51.92% female) with a median (minimum-maximum) age and body weight of 58 [21, 93] years and 81 [43.8, 139.3] Kg. A 1-compartment clearance model with linear elimination, incorporating biological index, serum creatinine, and drug type best fits the concentration-time data. The best radiomic biological age model included dorsal muscle group area, bone mineral density, visceral fat area, and subcutaneous fat density. The radiomic biological age model offered a modest improvement over the chronological age model. This work offers a proof-of-concept, highlighting the potential for more precise methods for aging-related kidney function estimation to aid personalized pharmacotherapy.

Different cutoff values of the skeletal muscle mass and myosteatosis result in different clinical impact on overall survival in oncology. A subanalysis of a clinical trial

BACKGROUND

Body composition analysis, particularly the assessment of sarcopenia and myosteatosis, has emerged as a potential prognostic tool in oncology. However, the clinical implication of body composition parameters remains inconsistent, largely due to the variability in cutoff values used across studies. This study examines the influence on prevalence and prognostic influence of different cutoff values for sarcopenia and myosteatosis in patients in a standardized cohort from a large clinical trial (SORAMIC).

METHODS

This study included 179 patients with unresectable liver cancer from the palliative arm of the SORAMIC trial. Skeletal muscle index (SMI) was calculated by measuring the cross-sectional area of skeletal muscle at the third lumbar vertebra (L3) on baseline CT scans. We then applied 14 published cutoff definitions for sarcopenia (SMI) and 7 for myosteatosis (muscle attenuation) to determine their prevalence in this cohort. Cox regression models were used to analyze the relationship between sarcopenia, myosteatosis, and OS.

RESULTS

The prevalence of sarcopenia ranged from 8.9% (Van der Werf et al.) to 69.8% (Lanic et al.). Overall, 3 of the 14 cutoffs [Van Vledder et al. (HR = 1.53, p = 0.03), Coelen et al. (HR = 1.46, p = 0.03), and Derstine et al. (HR = 1.47, p = 0.04)] showed a relevant association with OS. Other cut off values were not associated with OS. The prevalence of myosteatosis varied between 10.1% (Nachit et al.) and 53.1% (Zhang et al.). One of the 7 cutoffs (Chu et al.) demonstrated a relevant association with OS (HR = 1.53, p = 0.03).

CONCLUSION

The large variability in prevalence and prognostic impact observed across different cutoff definitions underscores the urgent need for standardized, cancer-specific cutoff values for SMI and muscle attenuation. Establishing uniform criteria will enhance the reliability and clinical applicability of body composition metrics as prognostic tools in oncology. Further research should focus on refining these cutoffs and validating them across diverse cancer populations.

The impact of CT-based adipose tissue distribution and sarcopenia on treatment outcomes in patients with high-risk soft tissue sarcoma

BACKGROUND

The prognostic and predictive value of obesity and sarcopenia remains poorly defined in patients with high-risk soft tissue sarcoma (HR-STS). We sought to correlate clinical outcomes with CT-based body composition parameters in patients with HR-STS undergoing a multimodal preoperative therapy. The impact of radiologic and histopathologic response to preoperative treatment was correlated with individual fat and muscle distribution.

METHODS

Patients with locally advanced non-abdominal HR-STS and treatment with preoperative chemotherapy + regional hyperthermia (RHT) +/- radiotherapy (RT) followed by surgery between 2015 and 2022 were retrospectively evaluated. Body composition parameters measured on baseline CT scans were correlated with clinical outcomes including event-free survival (EFS) and overall survival (OS) as well as radiologic and histopathologic treatment response.

RESULTS

A total of 85 patients were included. Body composition parameters showed no significant correlation with radiologic or histopathologic treatment response. High total fat indices such as the total fat index (TFI, HR 3.56, p = 0.005) and high total fat to muscle ratio (FMR, HR 3.22, p = 0.020) were strongly associated with poor OS. Parameters for sarcopenia including skeletal muscle index (SMI) were not significantly linked to survival outcomes.

CONCLUSION

High fat indices and a high FMR are strong predictors of poor OS in patients with HR-STS. Larger studies are warranted to further clarify the prognostic impact of sarcopenia and the predictive value of body composition parameters on preoperative treatment response.

BMI-stratified cutoff values for spinal sarcopenia in Chinese adults based on CT measures: a multicentre study

BACKGROUND

Decreased size and mass of paraspinal muscles are associated with lower vertebral bone mineral density, more postoperative complications, increased mortality, and spinal sagittal imbalance. However, it is difficult to determine muscle loss in older adults with overweight and obesity. This study aimed to investigate the effects of body mass index (BMI) and central obesity on paraspinal muscle aging and to determine cutoff values for low paraspinal muscle mass/quality in Chinese community populations.

METHODS

In this nationwide cross-sectional study, abdominal CT scans and basic information were collected and analyzed from 4,305 community-dwelling adults from twelve representative cities in China between 2013 and 2017. Psoas and posterior paraspinal muscle index (PMI and PSMI) and density (PMD and PSMD) at the L3 level were measured using OsiriX software. Correlation analysis, multiple linear regression, and one-way ANOVA were performed for statistical analysis. Commonly used cutoff value calculations were applied to define low muscle index and density (Mean-2SD, 5th percentile in young people, and 20th percentile in older people) in the general population and individuals with different BMIs.

RESULTS

Correlation analysis showed that the paraspinal muscle index and density were primarily correlated with sex, BMI, and age. Multiple linear regression analysis indicated that the paraspinal muscle index (PSMI and PMI) was primarily influenced by sex (β=-0.391 and - 0.599, p < 0.001) and BMI (β = 0.442 and 0.371, p < 0.001), followed by age and waist circumference. In contrast, muscle density (PSMD and PMD) was mainly associated with sex (β=-0.405 and - 0.317, p < 0.001) and age (β=-0.409 and - 0.429, p < 0.001), with a slight influence from WC and BMI. Considering the significant effect of BMI on muscle mass, we calculated BMI-stratified cutoffs for PSMI (as 12.3/10.6, 15.0/11.7, and 15.2/11.9 cm2/m2 in normal, overweight, and obese men/women using M-2SD), PMI (as 3.8/2.9, 5.0/3.4, and 4.9/3.9 cm2/m2 in normal, overweight and obese men/women using M-2SD), and unstratified cutoffs for PSMD (as 36.3 and 31.1 HU in men and women) and PMD (as 40.1 and 36.9 HU in men and women).

CONCLUSIONS

This study found that sex and BMI were key determinants of paraspinal muscle mass, with BMI influencing paraspinal muscle number more than age. In contrast, muscle density was primarily influenced by sex and age. This study provided BMI-stratified and non-stratified cutoff values for low paraspinal muscle index and density, which aided in the identification of spinal sarcopenia in individuals with different BMIs.

Body Composition Assessment in Critically Ill Adults - Where are We now?

This narrative review provides an overview of body composition methods available for use in critically ill patients. It focuses on the relevance and discussion of the most commonly used techniques. Further, we discuss the validity of these methods with a focus on muscle mass assessment, measuring changes over time and the identification of patients with lower-than-normal muscularity. Current available evidence, as well as future directions is highlighted.

Sarcopenia, Obesity, and Sarcopenic Obesity: Retrospective Audit of Electronic Health Record Documentation versus Automated CT Analysis in 17 646 Patients

Automated opportunistic CT analysis identified sarcopenia and sarcopenic obesity in 28.5% and 5.7% of 17 646 patients, respectively, contrasting with the 0.05% underreported in the electronic health record, which highlights the potential of artificial intelligence tools to mitigate sarcopenia underdiagnosis.

Evaluation of a Computed Tomography-based Technique for Predicting Atrial Fibrillation Recurrence Following Ablation Using an Adjusted Skeletal Muscle Index

Background

This research focuses on the unresolved question of how low muscle mass influences the likelihood of atrial fibrillation (AF) recurrence after ablation treatment. Despite the growing body of evidence highlighting the importance of muscle mass in cardiovascular health, the specific impact of low muscle mass on the recurrence of AF following ablation has yet to be well-established. Thus, this study evaluated the relationship between a low computed tomography (CT)-based skeletal muscle index (SMI) of muscle sites at the fourth thoracic level (T4-SMI) and AF recurrence post-radiofrequency ablation. Furthermore, this study aimed to determine whether the T4-SMI is a predictive marker for AF recurrence.

Methods

This study included 641 patients with AF who underwent radiofrequency ablation. T4 muscle sites were determined using SliceOmatic software. Height- and body mass index (BMI)-corrected SMIs were calculated.

Results

The lowest quartile in the T4-SMI group was defined for each sex as the "low SMI" group. The height-adjusted T4-SMI thresholds were 69.7 cm2/m2 for males and 55.91 cm2/m2 for females. The BMI-adjusted thresholds were 8.10 cm2/kg/m2 for males and 5.78 cm2/kg/m2 for females. After potential confounder adjustment, low T4-SMI was associated with a higher risk of AF recurrence. The correlation between T4-SMI (height) and AF recurrence was fully validated by constructing multiple models, and adjusting for different covariates barely altered the results. Fully adjusted models suggested that compared with the fourth T4-SMI (height) quartile, the risk odds ratio (OR) with a 95% confidence interval (CI) of the "low SMI" group was 1.57 (0.76-3.22). Finally, subgroup analysis and interaction according to gender, age, overweight/obesity, hypertension, or diabetes indicate that the differences between different layers are not significant.

Conclusions

Low CT-based BMI- or height-adjusted T4-SMIs were risk factors for AF recurrence post-radiofrequency ablation. A lower T4-SMI (height) significantly correlated with AF recurrence post-ablation, regardless of gender, age, or overweight/obesity. The height adjustment performed better than the BMI adjustment in that regard.

Skeletal muscle adiposity, coronary microvascular dysfunction, and adverse cardiovascular outcomes

BACKGROUND AND AIMS

Skeletal muscle (SM) fat infiltration, or intermuscular adipose tissue (IMAT), reflects muscle quality and is associated with inflammation, a key determinant in cardiometabolic disease. Coronary flow reserve (CFR), a marker of coronary microvascular dysfunction (CMD), is independently associated with body mass index (BMI), inflammation and risk of heart failure, myocardial infarction, and death. The relationship between SM quality, CMD, and cardiovascular outcomes is not known.

METHODS

Consecutive patients (n = 669) undergoing evaluation for coronary artery disease with cardiac stress positron emission tomography demonstrating normal perfusion and preserved left ventricular ejection fraction were followed over a median of 6 years for major adverse cardiovascular events (MACEs), including death and hospitalization for myocardial infarction or heart failure. Coronary flow reserve was calculated as stress/rest myocardial blood flow. Subcutaneous adipose tissue (SAT), SM, and IMAT areas (cm2) were obtained from simultaneous positron emission tomography attenuation correction computed tomography using semi-automated segmentation at the 12th thoracic vertebra level.

RESULTS

Median age was 63 years, 70% were female, and 46% were nonwhite. Nearly half of patients were obese (46%, BMI 30-61 kg/m2), and BMI correlated highly with SAT and IMAT (r = .84 and r = .71, respectively, P < .001) and moderately with SM (r = .52, P < .001). Decreased SM and increased IMAT, but not BMI or SAT, remained independently associated with decreased CFR (adjusted P = .03 and P = .04, respectively). In adjusted analyses, both lower CFR and higher IMAT were associated with increased MACE [hazard ratio 1.78 (95% confidence interval 1.23-2.58) per -1 U CFR and 1.53 (1.30-1.80) per +10 cm2 IMAT, adjusted P = .002 and P < .0001, respectively], while higher SM and SAT were protective [hazard ratio .89 (.81-.97) per +10 cm2 SM and .94 (.91-.98) per +10 cm2 SAT, adjusted P = .01 and .003, respectively]. Every 1% increase in fatty muscle fraction [IMAT/(SM + IMAT)] conferred an independent 2% increased odds of CMD [CFR <2, odds ratio 1.02 (1.01-1.04), adjusted P = .04] and a 7% increased risk of MACE [hazard ratio 1.07 (1.04-1.09), adjusted P < .001]. There was a significant interaction between CFR and IMAT, not BMI, such that patients with both CMD and fatty muscle demonstrated highest MACE risk (adjusted P = .02).

CONCLUSIONS

Increased intermuscular fat is associated with CMD and adverse cardiovascular outcomes independently of BMI and conventional risk factors. The presence of CMD and SM fat infiltration identified a novel at-risk cardiometabolic phenotype.

Quantitative evaluation of muscle mass based on chest high-resolution CT and its prognostic value for tuberculosis: a retrospective study

Objective

This study aims to explore the prognostic value of quantitatively evaluating muscle mass using chest high resolution computed tomography (HRCT) in patients with active tuberculosis (TB).

Methods

This retrospective cohort study collected data from 309 patients with active TB diagnosed at Ningbo No.2 Hospital from 2020 to 2023. Based on the skeletal muscle index (SMI) at the T12 vertebra (with thresholds of <28.8 cm2/m2 for men and <20.8 cm2/m2 for women), patients were divided into a low muscle mass group and a normal muscle mass group. The study compared baseline characteristics, muscle mass-related indicators, body mass index (BMI), and imaging features between the two groups. The correlation between muscle mass-related indicators, BMI, and TB imaging features and prognosis was analyzed. Receiver operating characteristic (ROC) curve analysis and multivariate logistic regression were used to assess the prognostic value of muscle mass-related indicators and BMI in patients undergoing anti-TB treatment.

Results

A total of 309 patients were included in the study, divided into a normal muscle mass group (n = 229) and a low muscle mass group (n = 80). There was a significant difference in prognosis between the two groups (χ 2 test, p < 0.05). Patients in the low muscle mass group were older, had a higher proportion of males, and had a lower BMI (p < 0.05). Additionally, these patients had a higher likelihood of developing pulmonary cavities (p < 0.05). In terms of imaging features, the two groups showed significant differences in the pre-treatment proportion of pulmonary fibrotic bands, ground-glass opacities, consolidation, lesion percentage, and lesion absorption ratio (all p < 0.05). Univariate analysis indicated that both the T12 skeletal muscle index (T12 SMI) and BMI were correlated with TB imaging characteristics (p < 0.05), with T12 SMI showing a stronger correlation than BMI. Multivariable linear regression analysis revealed that after adjusting for age, gender, and T12 skeletal muscle radiation attenuation (T12 SMRA), T12 SMI remained significantly correlated with the whole-lung lesion proportion (β: - 4.56, 95% CI [-5.45 to -3.67]) and lesion absorption ratio (β:0.036, 95% CI [0.031-0.041]). Multivariable logistic regression analysis demonstrated that after accounting for age, gender, T12 SMRA, T12 SMI was significantly associated with the prognosis of TB patients (OR: 20.10, 95% CI [8.81-51.56], p < 0.05), indicating that low T12 SMI is an independent risk factor associated with poor prognosis. ROC curve analysis indicated that T12 SMI may offer advantages over BMI, with an area under the ROC curve (AUC) of T12 SMI (0.761, 95% CI [0.690-0.832]) higher than the AUC of BMI (0.700, 95% CI [0.619-0.781].

Conclusion

Quantitative evaluation of muscle mass using chest HRCT, particularly the T12 SMI, may provide valuable prognostic information for tuberculosis patients, potentially offering advantages over BMI in assessing patient outcomes.

Optimal lumbar vertebral level for trunk muscle CT assessments in opportunistic sarcopenia screening: a cross-sectional study

OBJECTIVES

This study aims to identify the optimal lumbar vertebral level for CT-based assessments of trunk muscles in relation to physical function and muscle strength, and to establish a foundation for opportunistic CT screening for sarcopenia.

DESIGN

A cross-sectional study was conducted between April 2022 and December 2022. Pearson's correlation coefficients and multiple linear regression analyses were employed to estimate the correlation between CT parameters of trunk muscle with physical function and muscle strength.

SETTING AND PARTICIPANTS

The study included community residents aged 50 years and older from Kunming, Yunnan Province, China, who were part of the SOY (Sarcopenia and Osteoporosis Study of Yunnan) cohort. A total of 615 participants were enrolled, comprising 424 men and 191 women. Among these, 31 individuals (20 men and 11 women) were diagnosed with sarcopenia.

INTERVENTIONS

Each participant underwent lumbar CT scanning, the Short Physical Performance Battery (SPPB) and handgrip strength (HGS) assessment.

PRIMARY OUTCOME MEASURES

A correlation analysis was conducted for both the general and sarcopenia groups, after adjusting for age and body mass index. Additionally, a gender-stratified analysis was performed.

RESULTS

Muscle density and muscle area at all levels exhibited a moderate correlation with grip strength, with the correlation for muscle area being more pronounced (correlation β of muscle density =0.48-0.54, p value <0.001; correlation β of muscle area=0.66-0.68, p value <0.001). However, only muscle density demonstrated a weak correlation in the correlation analysis with SPPB (correlation β of muscle density =0.09-0.12, p value <0.01). When stratified by gender, trunk muscle attenuation at the L1 vertebral level in the male group showed a more pronounced correlation with physical performance (L1-βHGS =0.25, p value <0.001 vs L2-L5-βHGS =0.16-0.19, p value =0.01-0.04; L1-βSPPB =0.31, p value <0.001 vs L2-L5-βSPPB =0.23-0.29, p value <0.01). In the female cohort, both the muscle area and muscle density at all levels showed correlations with grip strength, and the muscle area at L3 vertebrae showed the best performance (L3-βHGS =0.23, p value <0.001). In the sarcopenia group, the L1 level correlates better with HGS and SPPB than other levels. (L1-βHGS =0.54, p value =0.03 and L1-βSPPB =-0.35, p value =0.04).

CONCLUSIONS

In this study, the area and density of lumbar muscles based on CT showed correlations of varying degrees with grip strength or SPPB. The L1 layer exhibited superior performance in those aged more than 50 years, especially in the male and sarcopenia groups. This study suggests that CT-based muscle assessment at the L1 vertebra may be a feasible option for opportunistic sarcopenia screening.

TRIAL REGISTRATION NUMBER

ChiCTR210005215; Pre-results.

Is Myopenia or Myosteatosis Clinically Relevant in Systemic Sclerosis? Skeletal Muscle Assessment Using Computed Tomography

OBJECTIVES

Systemic sclerosis (SSc) is a chronic autoimmune disease characterized by fibrosis, vascular damage, and immune dysregulation, often leading to muscle abnormalities. This study aimed to evaluate the prevalence of myopenia and myosteatosis in SSc patients using computed tomography (CT) and their associations with clinical features, including lung disease and esophageal dilatation.

MATERIALS AND METHODS

SSc patients followed at Gazi University Rheumatology Clinic (2000-2024) who had thoracic CT imaging were included. Muscle mass and density were assessed at the L1 vertebral level. Skeletal muscle area (SMA) and skeletal muscle radiation attenuation (SMRA) were measured to identify myopenia and myosteatosis. Lung disease involvement and widest esophageal diameter (WED) were assessed via CT. Statistical analyses explored correlations between muscle metrics and clinical variables, with multiple linear regression identifying predictors.

RESULTS

Among 95 patients (54.7% diffuse SSc, 45.3% limited SSc; mean age 57.04 ± 13.65 years; female-to-male ratio 8.5:1), myopenia and myosteatosis prevalence were 27.3% and 41.1%, respectively. Myosteatosis was associated with female sex (p = 0.001), older age (p = 0.001), higher BMI (p = 0.043), and inflammation markers (CRP, ESR). Myopenia correlated with BMI (p = 0.001) but not clinical outcomes. Higher WED correlated with lower SMRA (p = 0.001). BMI predicted muscle mass (R² = 0.42), while age, gender, and BMI determined SMRA (R² = 0.67, p < 0.001).

CONCLUSIONS

Myosteatosis was more prevalent and strongly associated with clinical features, including lung disease and esophageal dilatation, than myopenia, underscoring the importance of muscle quality.

Evaluation of nutritional parameters that may be associated with survival in patients with locally advanced non-small cell lung carcinoma receiving definitive concurrent chemoradiotherapy: retrospective study conducted in a tertiary pulmonary hospital

Sarcopenia, defined as skeletal muscle loss, is thought to be a hallmark of cancer cachexia. It has an impact on mortality, especially in cancer patients. There are also opposing views regarding the relationship between definitive concurrent chemoradiotherapy (CRT) and sarcopenia in locally advanced lung cancer. Our aim was to investigate the prognostic effect of sarcopenia in our patients with locally advanced stage III non-small cell lung cancer (NSCLC) who received definitive concurrent CRT by using many markers, and to determine the overall survival (OS). The study was designed as a retrospective cohort. 54 patients with stage III NSCLC who received definitive concurrent CRT at the Radiation Oncology Unit of Health Sciences University Izmir Dr Suat Seren Chest Diseases and Surgery Training Hospital, between January 1, 2018 and December 31, 2019, were included in the study.92% of our patients were sarcopenic with international L3-skeletal muscle index (SMI) and Psoas muscle index (PMI) threshold values. The mean OS time was 32.4 months, and the 4-year survival rate was 38.9%. While the new threshold values specific to our patient group were 26.21 for SMI and 2.94 for PMI, SMI and PMI did not indicate OS with these values. Even with the new values, most proposed criteria for sarcopenia did not indicate OS. However, low BMI (≤21.30), low serum albumin (≤4.24 mg/dl) and low visceral fat tissue area (≤37) in univariate analysis, and low visceral fat tissue area (≤37) in multivariate analysis indicated OS. OS was poor in patients with low fat tissue area. In patients with stage III NSCLC who received definitive concurrent CRT, low visceral fat tissue area (≤37) indicated OS, rather than SMI, PMI and other sarcopenia indices.

Clinical risk factors for sarcopenia in acute and chronic pancreatitis

BACKGROUND

Sarcopenia is common in chronic pancreatitis (CP) and has been associated with unfavorable outcomes; however, it is not well studied in acute pancreatitis (AP).

AIMS

To evaluate risk factors for sarcopenia among individuals with AP or CP.

METHODS

A cross sectional analysis was performed among subjects with AP or CP seen in a tertiary care Pancreas Clinic. TeraRecon software was used to calculate the cross-sectional area of skeletal muscle, visceral fat, and subcutaneous fat at the level of the L3 vertebrae. Sarcopenia was classified using sex-specific skeletal muscle index. Univariate and multivariate logistic regressions were performed to assess differences between groups and associations with sarcopenia.

RESULTS

A total of 49 subjects with AP and 54 subjects with CP were included. Sarcopenia was more frequently observed in CP compared to AP (83.3% vs. 46.9%, p < 0.001). The multivariate logistic regression demonstrated CP, male sex, increased age, and decreased subcutaneous fat were independently associated with sarcopenia.

CONCLUSION

Sarcopenia is observed in both CP and AP. In addition to traditional risk factors (including male sex, older age, and decreased subcutaneous fat), CP is independently associated with sarcopenia. Further investigations are necessary to gain deeper insights into sarcopenia pathogenesis, which could inform potential intervention strategies.

Non-cancerous CT findings as predictors of survival outcome in advanced non-small cell lung cancer patients treated with first-generation EGFR-TKIs

PURPOSE

To identify non-cancerous factors from baseline CT chest affecting survival in advanced non-small cell lung cancer (NSCLC) treated with first-generation Epidermal Growth Factor Receptor-Tyrosine Kinase Inhibitors (EGFR-TKIs).

METHODS

Retrospective study of 172 advanced NSCLC patients treated with first-generation EGFR-TKIs as a first-line systemic treatment (January 2012 to September 2022). Baseline CT chest assessed visceral/subcutaneous fat (L1 level), sarcopenia, and myosteatosis (multiple levels), main pulmonary artery (MPA) size, MPA to aorta ratio, emphysema, and bone mineral density. Cox regression analyzed prognostic factors at 18-month outcome.

RESULTS

Median overall survival was 17.57 months (14.87-20.10) with 76 (44.19%) patients died at 18 months. Deceased had lower baseline BMI (21.10 ± 3.44) vs. survived (23.25 ± 4.45) (p < 0.001). Univariable analysis showed 5 significant prognostic factors: low total adiposity with/without cutoff [HR 2.65 (1.68-4.18), p < 0.001; 1.00 (0.99-1.00), p = 0.006;], low subcutaneous adipose tissue (SAT) with/without cutoff [HR 1.95 (1.23-3.11), p = 0.005; 0.99 (0.98-0.99), p = 0.005], low SAT index (SATI) with/without cutoff [1.74 (1.10-2.78), p = 0.019; 0.98 (0.97-0.99), p = 0.003], high VSR [1.67 (1.06-2.62), p = 0.026], and high MPA size with/without cutoff [2.23 (1.23-4.04), p = 0.005; 1.09 (1.04-1.16), p = 0.001]. MPA size, MPA size > 29 mm, and total adiposity ≤85 cm2 remained significant in multivariable analysis, adjusted by BMI [HR 1.14 (1.07-1.21), p < 0.001; 3.10 (1.81-5.28), p < 0.001; 3.91 (1.63-9.40), p = 0.002]. There was no significant difference of sarcopenic and myosteatotic parameters between the two groups.

CONCLUSION

In advanced EGFR-mutated NSCLC patients, assessing pre-treatment prognosis is warranted to predict the survival outcome and guide decision regarding EGFR-TKI therapy. Enlarged MPA size, low total adiposity, and low subcutaneous fat (lower SAT, lower SATI, and higher VSR) are indicators of poor survival. Large MPA size (>29 mm) or low total adiposity (≤85 cm2) alone predict 18-month death.

The prognostic significance of sarcopenia in patients treated with definitive radiotherapy: A systematic review

Sarcopenia describes the degenerative loss of muscle mass and strength, and is emerging as a pan-cancer prognostic biomarker. It is linked with increased treatment toxicity, decreased survival and significant healthcare financial burden. Systematic analyses of sarcopenia studies have focused on outcomes in patients treated surgically or with systemic therapies. There are few publications concerning patients treated with radiotherapy. This manuscript presents a pan-cancer systematic review of the association between sarcopenia and survival outcomes in patients treated with definitive (chemo-)radiotherapy. A literature search was performed, with 26 studies identified, including a total of 5,784 patients. The prognostic significance of sarcopenia was mixed. This may reflect lack of consensus in methods used to measure skeletal muscle mass and define sarcopenia. Many papers analyse small samples and present sarcopenia cutoffs optimised on the local population, which may not generalise to external populations. Recent advances in artificial intelligence allow for automatic measurement of body composition by segmenting the muscle compartment on routinely collected imaging. This provides opportunity for standardisation of measurement methods and definitions across populations. Adopting sarcopenia diagnosis into clinical workflows could reduce futile treatments and associated financial burden, by reducing treatment toxicities, and improving treatment completion, patient survival, and quality-of-life after cancer.

Growth and physical development of children at apparent risk of sarcopenia

BACKGROUND

The consequences of sarcopenia on growth have received little attention. We analysed the potential risk resulting from the low lean mass for age expressed through the appendicular lean body mass index (aLBMI) and the ratio aLBM/trunk fat mass (trFM).

METHODS

The sample consisted of 580 participants 10-13 yrs evaluated twice in a 12-month interval: height, trFM, total and aLBM, whole-body bone mineral density less head (WBLH BMD), tibia and radius SOS, maturity and handgrip strength were measured. All variables except maturity and BMI were standardised according to sex and age group (Z-score) using the sample as a reference. A high risk of sarcopenia was identified for Z-scores ≤ -1 on aLBMI (Group B) or aLBM/trFM (Group C), while Z-scores > -1 on both markers were considered at low risk for sarcopenia (Group A). The ANCOVA adjusted for maturity was used to compare the three groups.

RESULTS

Girls showed a more significant decrease in the total BMC/LBM ratio in Group B and a minor increase in WBLH BMD in Group C (p < 0.050); boys in Group B showed a tendency to gain less height (p = 0.053).

CONCLUSION

The high risk of sarcopenia expressed through aLBMI or aLBM/trFM Z-score ≤ -1 compromises bone mineralisation in girls.

IMPACT

The findings emphasise the necessity of implementing routine screening protocols for sarcopenia risk within clinical environments and educational institutions. Such screenings should extend beyond merely assessing body mass index to encompass broader body composition variables like lean body mass. By integrating these assessments into routine health evaluations, healthcare professionals and educators can proactively identify at-risk individuals and initiate timely interventions for suboptimal physical growth and development.

Aged-Related Fibroblast Activation Protein Expression in Skeletal Muscles Evaluated by PET Imaging

BACKGROUND

Fibroblast activation protein (FAP) is prominently involved in the tumour microenvironment and tissue remodelling processes in most cancers, and its expression is also noted in normal skeletal muscle. This study aims to explore the relationship between FAP expression and age-related muscle characteristics through FAP inhibitor (FAPI) PET/CT imaging.

METHODS

This retrospective analysis studied 54 patients with lung cancer (n = 27) and pancreatic cancer (n = 27) using FAPI PET/CT. Imaging-based muscle features including the mean standardised uptake value (SUVmean), skeletal muscle index (SMI) and Hounsfield units (HU) were evaluated. Age-related FAP expression in skeletal muscles was also evaluated using the Genotype-Tissue Expression (GTEx) dataset. Statistical analyses included Spearman's rank correlation and Kruskal-Wallis test, with a p-value of less than 0.05 considered significant.

RESULTS

Analysis revealed a moderate to strong positive correlation between FAPI SUVmean and age (ρ = 0.368, p = 0.006), with older age groups showing higher muscle uptake. Within specific cohorts, the FAPI-74 group demonstrated a stronger correlation (ρ = 0.500, p = 0.008) compared to the FAPI-46 group (ρ = 0.319, p = 0.105). SUVmean also correlated negatively with muscle density (HU) (ρ = -0.298, p = 0.029), suggesting an association with higher fat infiltration. GTEx data supported these findings, showing a significant increase in FAP expression across age groups (p < 0.001), with the highest median FAP in the 70-79 age group.

CONCLUSIONS

This study demonstrates an age-related increase in FAPI uptake in skeletal muscle, correlated with changes in muscle density and fat infiltration. The role of FAP extends beyond pathology to normal muscle, indicating broader biological functions. Accordingly, FAPI PET shows promise for assessing age-related muscle health and quality.

Low Muscle Mass in the Internal Medicine Ward: Prevalence and Survival Implications

BACKGROUND

Low muscle mass is common in hospitalized patients. It is associated with adverse clinical outcomes. Reported prevalence varies widely due to non-universally accepted diagnostic criteria and the heterogeneity of the populations studied. Non-surgical ill patients are underrepresented in the literature.

AIMS

To estimate the prevalence of low muscle index and its impact on survival in patients admitted to an internal medicine unit.

METHODS

We prospectively enrolled patients with abdominal CT scans on admission to the Internal Medicine ward. We assessed muscle mass index (L3MI) at the level of the L3 lumbar vertebra. The primary outcome was to estimate the prevalence of low muscle mass on admission. Secondary outcomes were to determine the relationship of low L3MI with hospital mortality, length of stay, nosocomial infections, and hospital readmission.

RESULTS

One hundred and seven patients were included. The prevalence of low L3MI was 46.7%. An L3MI of 46.3 cm2/m2 in men and 40.9 cm2/m2 in women predicted death at one year with a sensitivity of 66% and a specificity of 78% (AUC = 0.62 [95% CI 0.38-0.86]) and 69 and 66% (AUC of 0.63 [95% IC 0.47-0.78]), respectively. In-hospital mortality, death at 60, 90, and 360 d, and hospital readmission were significantly higher in patients with low L3MI.

CONCLUSION

Almost half of the patients admitted to an internal medicine ward have low muscle mass index. The cutoff point of 40.9 cm2/m2 in females and 46.3 cm2/m2 in males predicts relevant clinical variables. We established the better L3MI cutoff value to predict 12-month mortality.

Preoperative Chest CT Myosteatosis Indicates Worse Postoperative Survival in Stage 0-IIB Non-Small Cell Lung Cancer

Background Skeletal muscle density (SMD) and intermuscular adipose tissue (IMAT) are myosteatosis markers. The prognostic value of myosteatosis markers in preoperative risk stratification of patients with early-stage non-small cell lung cancer (NSCLC) remains unknown. Purpose To assess whether increased myosteatosis markers at chest CT before lung resection of early-stage NSCLC are associated with and predictive of worse overall survival (OS). Materials and Methods This retrospective cohort study included patients with stage 0-IIB NSCLC who underwent lobectomy or bilobectomy at three hospitals between 2014 and 2017. The indexes (cross-sectional area [in centimeters squared] divided by height [in meters squared]) and densities (mean attenuation [in Hounsfield units]) of skeletal muscle, subcutaneous adipose tissue (SAT), and IMAT were assessed at CT at the level of the 12th thoracic vertebral body via semiautomated threshold-based segmentation. Associations of SMD and the IMAT index with OS were evaluated via separate Cox proportional hazards models adjusted for skeletal muscle index, SAT index, SAT density, and relevant confounders. The ability of indexes and densities to predict OS was explored with penalized Cox proportional hazards models and internally validated concordance statistics. Results Among 838 patients (median age, 68 years [IQR, 61-74 years]; 475 [56.7%] female patients), 219 died after a median follow-up of 5.3 years (IQR, 3.0-6.4 years). Increased myosteatosis, represented by decreased SMD and an increased IMAT index, was associated with worse OS (adjusted hazard ratio, 0.87 [95% CI: 0.80, 0.93]; P < .001 and adjusted hazard ratio, 1.24 [95% CI: 1.12, 1.37]; P < .001, respectively). There was no evidence of an association between OS and skeletal muscle index, SAT index, and SAT density. The predictive performance (concordance) increased from 0.723 (95% CI: 0.686, 0.753) to 0.731 (95% CI: 0.692, 0.762) after including myosteatosis markers. Conclusion Increased thoracic myosteatosis markers were associated with worse OS after lobectomy or bilobectomy of stage 0-IIB NSCLC, independent of skeletal muscle index, SAT index, and SAT density, and improved OS prediction. © RSNA, 2025 Supplemental material is available for this article.

The effect of pre-existing sarcopenia on outcomes of critically ill patients treated for COVID-19

Background

Sarcopenia, defined by a loss of skeletal muscle mass and function, has been identified as a prevalent condition associated with poor clinical outcome among critically ill patients. This study aims to evaluate the impact of pre-existing sarcopenia on outcomes in critically ill patients with acute respiratory failure (ARF) due to COVID-19.

Material and Methods

A retrospective study was carried out on COVID-19 patients admitted to intensive care. Pre-existing sarcopenia was assessed using early CT scans. Clinical outcomes, including duration of high-flow oxygenation (HFO), mechanical ventilation (MV), length of hospital stay (LOS) and ICU mortality, were evaluated according to sarcopenia status.

Results

Among the studied population, we found a high prevalence (75 patients, 50%) of pre-existing sarcopenia, predominantly in older male patients. Pre-existing sarcopenia significantly impacted HFO duration (6.8 (+/-4.4) vs. 5 (+/-2.9) days; p=0.005) but did not significantly affect MV requirement (21 (28%) vs. 23 (37.3%); p=185), MV duration (7 vs. 10 days; p=0.233), ICU mortality (12 (16%) vs. 10 (13.3 %); p=0.644) or hospital LOS (27 vs. 25 days; p=0.509). No differences in outcomes were observed between sarcopenic and non-sarcopenic obese patients.

Conclusions

Pre-existing sarcopenia in critically ill COVID-19 patients is associated with longer HFO duration but not with other adverse outcomes. Further research is needed to elucidate the mechanisms and broader impact of sarcopenia on septic critically ill patient outcomes.

Sarcopenia diagnosed by computed tomography predicts postoperative complications in advanced epithelial ovarian cancer

BACKGROUND & AIMS

Surgery combined with chemotherapy remains the mainstay of treatment for advanced epithelial ovarian cancer. It is important to evaluate the occurrence of postoperative complications before operation and to prevent them. The purpose of this study is to investigate the role of sarcopenia diagnosed by CT scans in predicting postoperative complications in patients with ovarian cancer.

METHODS

Patients with PDS or IDS in the First Affiliated Hospital of Wenzhou Medical University from August 2017 to August 2022 were included. Sarcopenia was identified using CT scans at the T12 level. According to the Clavien-Dindo classification, postoperative complications are considered to have occurred in grades 2 and above. Logistic regression analysis was used to identify risk factors contributing to postoperative complications. P < 0.05 was considered statistically significant.

RESULTS

A total of 139 patients were included. Sarcopenia was observed in 24(17.27%) patients with advanced epithelial ovarian cancer. Compared to the non-sarcopenia group, the sarcopenia group had a higher incidence of postoperative complications (62.50% VS 42.61%, p = 0.032). Multivariate logistic analysis confirmed sarcopenia (OR = 3.241, p = 0.026), age over 65 years (OR = 3.296, p = 0.005), and intraoperative bleeding (OR = 1.002, p < 0.001) as independent predictors of postoperative complications in ovarian cancer.

DISCUSSION & CONCLUSIONS

Sarcopenia diagnosed based on CT body composition analysis may serve as a potential predictor for postoperative complications. Further research is warranted to explore preventive strategies and interventions to improve outcomes in this population.

[18F]FDG PET/CT beyond staging: Prognostic significance of sarcopenia and adipose tissue metabolism in esophageal carcinomas

AIM

This study aimed to investigate the relationship between PET and CT parameters and sarcopenia, adipose tissue, and tumor metabolism in esophageal carcinoma (EC) and its impact on survival in EC.

METHOD

Our study included 122 EC patients who underwent PET/CT for staging. Muscle and adipose tissue characteristics were evaluated, including lumbar (L3) and cervical (C3) muscle areas, psoas major (PM) and sternocleidomastoid muscle (SCM) parameters, and PET parameters for visceral and subcutaneous adipose tissue (SAT). Sarcopenia was determined using CT images, with a threshold for muscle tissue at the L3 vertebral level, and its impact on overall survival (OS) was investigated.

RESULTS

Sarcopenia was detected in 48 patients. SULmax in the primary tumor (PT) was significantly higher in sarcopenic patients (SP). The frequency of distant metastasis was higher in SP and OS was significantly lower. In the locally advanced stage, sarcopenia status decreased survival. L3, PM, C3, and SCM muscle areas were highly correlated. Subcutaneous adipose tissue SUVmax was significantly increased in SP and those with distant metastasis. Univariate analysis identified PT SULmax, PT SUVmean, PT TLG, lymph node and distant metastasis, SAT SUVmax, and sarcopenia as poor prognostic factors, while multivariate analysis confirmed BMI, distant metastasis, PT SUVmean, PT TLG as independent predictors of OS.

CONCLUSION

This study demonstrated that sarcopenia, linked to reduced survival, correlates with primary tumor SULmax, distant metastasis, and subcutaneous tissue PET parameters, exerting a notable impact on survival, particularly in locally advanced stages. Attenuation-corrected CT can be used instead of diagnostic CT, and sarcopenia can be diagnosed using not only L3 but also C3 slices.

Body composition of metabolically unhealthy normal-weight patients with aortic stenosis: a prospective cohort study

BACKGROUND

The aim of this study was to evaluate the prognostic impact of computed tomography (CT)-based body composition parameters in metabolically unhealthy normal-weight patients (MUHNW) with aortic stenosis (AS) undergoing transcatheter aortic valve replacement (TAVR).

METHODS

This prospective cohort study involved adults with normal weight scheduled for TAVR. Patients were divided into two groups: metabolically healthy normal-weight (MHNW) and MUHNW. The primary outcome was major adverse cardiovascular events (MACEs), and the secondary outcomes were all-cause mortality and prolonged hospital stay. Logistic regression was used to explore the relationships between variables and outcomes, and Cox regression models were applied to examine the effects of different parameters on patient prognosis. Incremental discriminative improvement (IDI) and the C-index were used to determine the influence of hybrid parameters on the predictive efficiency of the model.

RESULTS

The cohort study included 182 patients divided into two groups: MHNW metabolically healthy normal-weight (n = 97) and MUHNW (n = 85). Over a median follow-up of 0.8 years, multivariable logistic regression analysis revealed significant associations of the skeletal muscle index (SMind) (HR: 0.50, 95% CI: 0.29 - 0.84, p = 0.01), subcutaneous adipose tissue index (SATind) (HR: 0.63, 95% CI: 0.45 - 0.88, p = 0.01), and visceral adipose tissue index (VATind) (HR: 1.34, 95% CI: 1.10 - 1.63, p < 0.01) with the risk of experiencing MACEs, whereas epicardial adipose tissue (EAT) was not significantly associated with the risk of experiencing MACEs in the multivariable model (HR: 1.10, 95% CI: 0.97 - 1.24, p = 0.14). For the primary outcome, adjusted for significant covariates, the model had an IDI of 0.25 and a C-index of 0.8, with significant associations of SMind (HR: 0.73, 95% CI: 0.62 - 0.87, p < 0.01), SATind (HR: 0.87, 95% CI: 0.78 - 0.97, p = 0.01), and VATind (HR: 1.25, 95% CI: 1.12-1.40, p < 0.01) with the risk of experiencing MACEs. For the secondary outcome, the model had an IDI of 0.36 and a C-index of 0.93, with EAT showing a significant protective effect against all-cause mortality and prolonged hospital stay (HR: 0.97, 95% CI: 0.93 - 0.99; p = 0.04).

CONCLUSIONS

Body composition parameters, including, VATind, SMind, and SATind, are significant predictors of MACEs in patients undergoing TAVR. Additionally, EAT shows a significant protective effect against all-cause mortality and prolonged hospital stay. These findings highlight the potential importance of comprehensive body composition assessments in the risk stratification and management of AS patients.

Skeletal Muscle Mass Loss Leads to Prolonged Mechanical Ventilation and Higher Tracheotomy Rates in Critically Ill Patients

Background: Skeletal muscle mass depletion adversely affects critically ill patient outcomes. Standardized methods for assessing muscle mass in this population are limited, particularly regarding changes during ICU stays and their implications for risk stratification. Methods: In this secondary analysis of our prospective data registry of surgical ICU patients, we used a single slice extracted from a computed tomography scan to determine the patient's direction of absolute change in skeletal muscle mass between two different time points (-14 d to +0 d and +5 d to +21 d) during his or her critical illness. Results: In total, 98 surgical patients were included in the final analysis. A decrease in a patient's skeletal muscle mass is associated with prolonged mechanical ventilation compared to patients whose skeletal muscle mass remained the same or increased (415 vs. 42 h, p = 0.003). Patients losing skeletal muscle mass also needed to be ventilated more frequently (88.3% vs. 60.5%, p = 0.002), had a higher rate of tracheotomy (50.0% vs. 23.7%, p = 0.011), and had an increased ICU length of stay (22 vs. 13 days, p = 0.045). Conclusions: A decreased skeletal muscle index in early critical illness negatively impacts ventilation parameters, highlighting the importance of monitoring and managing muscle mass changes to optimize outcomes in ICU patients.

Ethnic differences in CT derived abdominal body composition measures: a comparative retrospect pilot study between European and Inuit study population

Understanding ethnic variations in body composition is crucial for assessing health risks. Universal models may not suit all ethnicities, and there is limited data on the Inuit population. This study aimed to compare body composition between Inuit and European adults using computed tomography (CT) scans and to investigate the influence of demographics on these measurements. A retrospective analysis was conducted on 50 adults (29 Inuit and 21 European) who underwent standard trauma CT scans. Measurements focused on skeletal muscle index (SMI), various fat indices, and densities at the third lumbar vertebra level, analyzed using the Wilcoxon-Mann-Whitney test and multiple linear regression. Inuit women showed larger fat tissue indices and lower muscle and fat densities than European women. Differences in men were less pronouncehd, with only Intramuscular fat density being lower among Inuit men. Regression indicated that SMI was higher among men, and skeletal muscle density decreased with Inuit ethnicity and age, while visceral fat index was positively associated with age. This study suggests ethnic differences in body composition measures particularly among women, and indicates the need for Inuit-specific body composition models. It higlights the importance of further research into Inuit-specific body composition measurements for better health risk assessment.

The chest CT perspective on sarcopenia: Exploring reference values for muscle mass quantity/quality and its application in elderly adults

OBJECTIVE

To determine reference values for diagnosing sarcopenia through chest CT scans and evaluate their suitability for use among the Chinese elderly population.

METHODS

Chest CT scans were obtained from 500 healthy individuals aged 19-39. Skeletal muscle mass was assessed on chest CT at the level of T4 by the skeletal muscle area (T4SMA), skeletal muscle index (T4SMI), T12 erector spinae muscle area (T12ESMA), and T12 skeletal muscle index (T12SMI), as well as skeletal muscle density (SMD) at T4 and T12 levels. The diagnostic threshold for sarcopenia was defined as a gender-specific value below 2 SD of the mean value in the young group. These cutoff values were then applied to a group of older adults aged 65 and over.

RESULTS

Diagnostic thresholds for low skeletal muscle in men were 110.05 cm², 36.01 cm²/m², 29.56 cm², and 9.65 cm²/m² for T4SMA, T4SMI, T12ESMA, and T12SMI, respectively. For women, the thresholds were: 69.93 cm², 26.51 cm²/m², 17.84 cm²/m², and 6.87 cm²/m², respectively. Diagnostic thresholds for low SMD were 38.63HU in men, 34.74 HU for women at T4 level. At T12 level, the cutoff values were 40.94 HU for men and 36.63 HU for women. Sarcopenia prevalence in men, defined by T4SMA, T4SMI, T12ESMA, and T12SMI cutoffs, was 35.6%, 18.9%, 36.7%, and 23.7%, respectively. In women, sarcopenia prevalence was 5.1%, 3.2%, 3.2%, and 1.9%, respectively.

CONCLUSION

This study established reference values for sarcopenia diagnosis through chest CT scans among the Chinese population, highlighting the importance of utilizing chest CT scans for sarcopenia detection and muscle health monitoring in older adults.

Integrating 18F-FDG PET/CT radiomics and body composition for enhanced prognostic assessment in patients with esophageal cancer

BACKGROUND

This study aimed to develop a predictive model utilizing radiomics and body composition features derived from 18F-FDG PET/CT scans to forecast progression-free survival (PFS) and overall survival (OS) outcomes in patients with esophageal squamous cell carcinoma (ESCC).

METHODS

We analyzed data from 91 patients who underwent baseline 18F-FDG PET/CT imaging. Radiomic features extracted from PET and CT images and subsequent radiomics scores (Rad-scores) were calculated. Body composition metrics were also quantified, including muscle and fat distribution at the L3 level from CT scans. Multiparametric survival models were constructed using Cox regression analysis, and their performance was assessed using the area under the time-dependent receiver operating characteristic (ROC) curve (AUC) and concordance index (C-index).

RESULTS

Multivariate analysis identified Rad-scorePFS (P = 0.003), sarcopenia (P < 0.001), and visceral adipose tissue index (VATI) (P < 0.001) as independent predictors of PFS. For OS, Rad-scoreOS (P = 0.001), sarcopenia (P = 0.002), VATI (P = 0.037), stage (P = 0.042), and body mass index (BMI) (P = 0.008) were confirmed as independent prognostic factors. Integration of the Rad-score with clinical variables and body composition parameters enhanced predictive accuracy, yielding C-indices of 0.810 (95% CI: 0.737-0.884) for PFS and 0.806 (95% CI: 0.720-0.891) for OS.

CONCLUSIONS

This study underscored the potential of combining Rad-score with clinical and body composition data to refine prognostic assessment in ESCC patients.

Impact of sarcopenia on the prognosis of patients with advanced non-small cell lung cancer treated with antiangiogenic therapy: A propensity score matching analysis

BACKGROUND

Limited information is available regarding the impact of sarcopenia on the prognosis of antiangiogenic therapy in individuals with advanced non-small cell lung cancer (NSCLC). This study primarily sought to examine the prognostic significance of sarcopenia in individuals with advanced NSCLC undergoing antiangiogenic therapy.

METHODS

We retrospectively enrolled all patients who met the inclusion and exclusion criteria from 2019 to 2021 at Nantong University Hospital. Patients were grouped according to the presence or absence of sarcopenia. After propensity score matching (PSM), progression-free survival (PFS), overall survival (OS), and adverse event rates were compared between the two groups. Factors associated with prognosis were screened using univariate and multivariate analyses.

RESULTS

A total of 267 patients were included, with a total of 201 matched at baseline after PSM (77 in the sarcopenia group and 124 in the non-sarcopenia group). The sarcopenia group had lower PFS (p = 0.043) and OS (p = 0.011) than the non-sarcopenia group and a higher incidence of adverse events (p = 0.044). Multivariate analysis suggested that sarcopenia is an independent prognostic risk factor for OS in advanced NSCLC patients receiving antiangiogenic therapies (p = 0.009). Results of subgroup analyses showed some differences in the impact of sarcopenia on survival prognosis in populations with different characteristics.

CONCLUSION

Patients with advanced NSCLC with comorbid sarcopenia exhibit a worse prognosis when treated with antiangiogenic therapy, and preventing and ameliorating sarcopenia may lead to better survival outcomes in patients with advanced NSCLC.

Impact of sarcopenia and fat distribution on outcomes in penile cancer

Sarcopenia, defined as age-associated loss of skeletal muscle function and muscle mass, is a negative prognostic marker for survival in several tumor entities. However, data evaluating the impact of sarcopenia and fat distribution on penile cancer are rarely described. We performed a retrospective study including 38 patients who were diagnosed with squamous cell carcinoma of the penis. By measuring skeletal muscle mass and fat distribution at axial abdominal computed tomography images at the third lumbar vertebra several body composition parameters including skeletal muscle index (SMI), psoas muscle index (PMI), visceral obesity and visceral-to-subcutaneous fat ratio were determined. Among 38 patients, 26% (n = 10) of the patients with penile cancer were identified as sarcopenic. SMI, age, lymph node metastases, distant metastases and penile cancer of the shaft were identified as significant risk factors for overall survival. PMI and distant metastases were significantly associated with cancer specific survival. None of the analysed adipose tissue parameters could be identified as risk factors for survival in this study. We showed that sarcopenia occurs in a relevant part of patients with penile cancer and is a significant risk factor for overall survival (p = 0.032) and cancer specific survival (p = 0.034) for patients with penile cancer. Regarding fat distribution further studies are needed to evaluate its impact on sarcopenia and survival.

Validating the use of body mass index with computed tomography in a racially and ethnically diverse cohort of patients admitted with SARS-CoV-2

BACKGROUND

Body mass index (BMI) is criticized for being unjust and biased in relatively healthy racial and ethnic groups. Therefore, the current analysis examines if BMI predicts body composition, specifically adiposity, in a racially and ethnically diverse acutely ill patient population.

METHODS

Patients admitted with SARS-CoV-2 having an evaluable diagnostic chest, abdomen, and/or pelvic computed tomography (CT) study (within 5 days of admission) were included in this retrospective cohort. Cross-sectional areas (centimeters squared) of the subcutaneous adipose tissue (SAT), visceral adipose tissue (VAT), and intramuscular adipose tissue (IMAT) were quantified. Total adipose tissue (TAT) was calculated as sum of these areas. Admission height and weight were applied to calculate BMI, and self-reported race and ethnicity were used for classification. General linear regression models were conducted to estimate correlations and assess differences between groups.

RESULTS

On average, patients (n = 134) were aged 58.2 (SD = 19.1) years, 60% male, and racially and ethnically diverse (33% non-Hispanic White [NHW], 33% non-Hispanic Black [NHB], 34% Hispanic). Correlations between BMI and SAT and BMI and TAT were strongest revealing estimates of 0.707 (0.585, 0.829) and 0.633 (0.534, 0.792), respectively. When examining the various adiposity compartments across race and ethnicity, correlations were similar and significant differences were not detected for TAT with SAT, VAT, or IMAT (all P ≥ 0.05).

CONCLUSIONS

These findings support the routine use of applying BMI as a proxy measure of total adiposity for acutely ill patients identifying as NHW, NHB, and Hispanic. Our results inform the validity and utility of this tool in clinical nutrition practice.

Impact of Sarcopenia on Treatment Outcomes and Toxicity in Locally Advanced Rectal Cancer

Background and Objectives: Sarcopenia, a condition characterized by muscle mass loss, is prevalent in up to 68% of rectal cancer patients and has been described as a negative prognostic factor, impacting overall survival and tumor response. While there are extensive data on rectal cancer globally, only a handful of studies have evaluated the role of sarcopenia in locally advanced rectal cancer (LARC). Our study aimed to investigate the relationship between sarcopenia, overall response rate, and toxicity in patients who underwent total neoadjuvant treatment (TNT) for LARC. Materials and Methods: We performed a retrospective study of patients with rectal cancer treated with TNT and surgery with curative intent between 2021 and 2023 at Prof. Dr. Ion Chiricuta Institute of Oncology, Cluj-Napoca. Sarcopenia was assessed on MRI images by measuring the psoas muscle area (PMA) at the level of the L4 vertebra before and after neoadjuvant therapy. The primary endpoints were the overall complete response rate (oCR) and acute toxicity. Results: This study included 50 patients with LARC. The oCR rate was 18% and was significantly associated with post-treatment sarcopenia (OR 0.08, p = 0.043). Patients who did not achieve a clinical or pathologic complete response had, on average, an 8% muscle loss during neoadjuvant therapy (p = 0.022). Cystitis and thrombocytopenia were significantly associated with post-treatment sarcopenia (p = 0.05 and p = 0.049). Conclusions: Sarcopenia and loss of psoas muscle during neoadjuvant therapy were negatively associated with tumor response in locally advanced rectal cancer. Thrombocytopenia and cystitis are more frequent in sarcopenic than non-sarcopenic patients undergoing neoadjuvant chemoradiation for rectal cancer.

Prognostic value of computed tomography‑derived skeletal muscle index and radiodensity in patients with gastric cancer after curative gastrectomy

The association of computed tomography (CT)-derived skeletal muscle index (SMI) and skeletal muscle radiodensity (SMD) with postoperative prognosis in patients with gastric cancer (GC) remains unknown. Therefore, the present study aimed to assess the association between SMI and SMD with 5-year overall survival (OS) and recurrence-free survival (RFS) in patients with GC. SMI and SMD were measured preoperatively in patients who underwent gastrectomy. Patients were categorized into Groups 1 (high SMI and SMD), 2 (high SMI or SMD) and 3 (low SMI and SMD). OS and RFS rates were assessed using Kaplan-Meier analysis and the log-rank test. Among 459 patients, OS and RFS rates were significantly lower in the low-SMD group than in the high-SMD group (OS, 83.4% vs. 88.8%, respectively; P=0.04 and RFS, 80.5% vs. 87.2%, respectively; P=0.02). OS and RFS rates were also significantly lower in Group 3 than in Groups 2 and 1 (P=0.006). Multivariate analysis revealed that a low SMI and SMD (Group 3) was a significant independent prognostic factor for OS [hazard ratio (HR), 2.32; 95% confidence interval (CI), 1.17-4.59; P=0.016] and RFS (HR, 2.28; 95% CI, 1.19-4.37; P=0.013). In summary, low SMI and SMD values may be useful postoperative prognostic indicators for patients with GC.

Three-dimensional numerical schemes for the segmentation of the psoas muscle in X-ray computed tomography images

The analysis of the psoas muscle in morphological and functional imaging has proved to be an accurate approach to assess sarcopenia, i.e. a systemic loss of skeletal muscle mass and function that may be correlated to multifactorial etiological aspects. The inclusion of sarcopenia assessment into a radiological workflow would need the implementation of computational pipelines for image processing that guarantee segmentation reliability and a significant degree of automation. The present study utilizes three-dimensional numerical schemes for psoas segmentation in low-dose X-ray computed tomography images. Specifically, here we focused on the level set methodology and compared the performances of two standard approaches, a classical evolution model and a three-dimension geodesic model, with the performances of an original first-order modification of this latter one. The results of this analysis show that these gradient-based schemes guarantee reliability with respect to manual segmentation and that the first-order scheme requires a computational burden that is significantly smaller than the one needed by the second-order approach.

Relative muscle indices and healthy reference values for sarcopenia assessment using T10 through L5 computed tomography skeletal muscle area

Sarcopenia is the age-related loss of skeletal muscle mass and function. Computed tomography (CT) assessments of sarcopenia utilize measurements of skeletal muscle cross-sectional area (SMA), radiation attenuation (SMRA), and intramuscular adipose tissue (IMAT). Unadjusted SMA is strongly correlated with both height and body mass index (BMI); therefore, SMA must be adjusted for body size to assess sarcopenic low muscle mass fairly in individuals of different heights and BMI. SMA/height (rather than S M A / h e i g h t 2 ) provides optimal height adjustment, and vertebra-specific relative muscle index (RMI) equations optimally adjust for both height and BMI. Since L3 measurement is not available in all CT scans, sarcopenic low muscle mass may be assessed using other levels. Both a mid-vertebral slice and an inferior slice have been used to define 'L3 SMA', but the effect of vertebral slice location on SMA measurements is unexplored. Healthy reference values for skeletal muscle measures at mid- and inferior vertebra slices between T10 and L5, have not yet been reported. We extracted T10 through L5 SMA, SMRA, and IMAT at a mid-vertebral and inferior slice using non-contrast-enhanced CT scans from healthy, adult kidney donor candidates between age 18 and 73. We compared paired differences in SMA between the mid-vertebral slice versus the inferior slice. We calculated the skeletal muscle gauge as S M G HT = S M R A ∗ S M I HT . We used allometric analysis to find the optimal height scaling power for SMA. To enable comparisons with other published reference cohorts, we computed two height-adjusted measures; S M I HT = S M A / h e i g h t (optimal) and S M I H T 2 = S M A / h e i g h t 2 (traditional). Using the young, healthy reference cohort, we utilized multiple linear regression to calculate relative muscle index z-scores ( R M I HT , R M I H T 2 ), which adjust for both height and BMI, at each vertebra level. We assessed Pearson correlations of each muscle area measure versus age, height, weight, and BMI separately by sex and vertebra number. We assessed the differences in means between age 18-40 versus 20-40 as the healthy, young adult reference group. We reported means, standard deviations, and sarcopenia cutpoints (mean-2SD and 5th percentile) by sex and age group for all measures. Sex-specific allometric analysis showed that height to the power of one was the optimal adjustment for SMA in both men and women at all vertebra levels. Differences between mid-vertebra and inferior slice SMA were statistically significant at each vertebra level, except for T10 in men. S M I HT was uncorrelated with height, whereas S M I H T 2 was negatively correlated with height at all vertebra levels. Both S M I HT and S M I H T 2 were positively correlated with BMI at all vertebra levels. R M I HT was uncorrelated with BMI, weight, and height (minimal positive correlation in women at L3 inf , L4 mid , and L5 inf ) whereas R M I H T 2 was uncorrelated with BMI, but negatively correlated with height and weight at all levels. There were no significant differences in SMA between 18-40 versus 20-40 age groups. Healthy reference values and sarcopenic cutpoints are reported stratified by sex, vertebra level, and age group for each measure. Height to the power of one (SMA/height) is the optimal height adjustment factor for SMA at all levels between T10 mid through L5 inf . The use of S M A / h e i g h t 2 should be discontinued as it retains a significant negative correlation with height and is therefore biased towards identifying sarcopenia in taller individuals. Measurement of SMA at a mid-vertebral slice is significantly different from measurement of SMA at an inferior aspect slice. Reference values should be used for the appropriate slice. We report sarcopenic healthy reference values for skeletal muscle measures at the mid-vertebral and inferior aspect slice for T10 through L5 vertebra levels. Relative muscle index (RMI) equations developed here minimize correlation with both height and BMI, producing unbiased assessments of relative muscle mass across the full range of body sizes. We recommend the use of these RMI equations in other cohorts.

Quantification of muscle recovery in post-ICU patients admitted for acute pancreatitis: a longitudinal single-center study

OBJECTIVES

Critically ill patients with severe pancreatitis exhibit substantial muscle wasting, which limits in-hospital and post-hospital outcomes. Survivors of critical illness undergo extensive recovery processes. Previous studies have explored pancreatic function, quality of life, and costs post-hospitalization for AP patients, but none have comprehensively quantified muscle loss and recovery post-discharge. By applying an AI-based automated segmentation tool, we aimed to quantify muscle mass recovery in ICU patients after discharge.

MATERIALS

Muscle segmentation was performed on 22 patients, with a minimum of three measurements taken during hospitalization and one clinically indicated examination after hospital discharge. Changes in psoas muscle area (PMA) between admission, discharge and follow up were calculated. T-Test was performed to identify significant differences between patients able and not able to recover their muscle mass.

RESULTS

Monitoring PMA shows muscle loss during and gain after hospitalization: The mean PMA at the first scan before or at ICU admission (TP1) was 17.08 cm², at the last scan before discharge (TP2), mean PMA was 9.61 cm². The percentage change in PMA between TP1 and TP2 ranged from - 85.42% to -2.89%, with a mean change of -40.18%. The maximum muscle decay observed during the stay was - 50.61%. After a mean follow-up period of 438.73 days most patients (81%) were able to increase their muscle mass. Compared to muscle status at TP1, only 27% of patients exhibited full recovery, with the majority still presenting a deficit of 31.96%.

CONCLUSION

Muscle recovery in ICU patients suffering from severe AP is highly variable, with only about one third of patients recovering to their initial physical status. Opportunistic screening of post-ICU patient recovery using clinically indicated imaging and AI-based segmentation tools enables precise quantification of patients' muscle status and can be employed to identify individuals who fail to recover and would benefit from secondary rehabilitation. Understanding the dynamics of muscle atrophy may improve prognosis and support personalized patient care.

Sarcopenia is associated with chemoradiotherapy discontinuation and reduced progression-free survival in glioblastoma patients

PURPOSE

Sarcopenia may complicate treatment in cancer patients. Herein, we assessed whether sarcopenia measurements derived from radiation planning computed tomography (CT) were associated with complications and tumor progression during radiochemotherapy for glioblastoma.

METHODS

Consecutive patients undergoing radiotherapy planning for glioblastoma between 2010 and 2021 were analyzed. Retrocervical muscle cross-sectional area (CSA) was measured via threshold-based semi-automated radiation planning CT analysis. Patients in the lowest sex-specific quartile of muscle measurements were defined as sarcopenic. We abstracted treatment characteristics and tumor progression from the medical records and performed uni- and multivariable time-to-event analyses.

RESULTS

We included 363 patients in our cohort (41.6% female, median age 63 years, median time to progression 7.7 months). Sarcopenic patients were less likely to receive chemotherapy (p < 0.001) and more likely to be treated with hypofractionated radiotherapy (p = 0.005). Despite abbreviated treatment, they more often discontinued radiotherapy (p = 0.023) and were more frequently prescribed corticosteroids (p = 0.014). After treatment, they were more often transferred to inpatient palliative care treatment (p = 0.035). Finally, progression-free survival was substantially shorter in sarcopenic patients in univariable (median 5.1 vs. 8.4 months, p < 0.001) and multivariable modeling (hazard ratio 0.61 [confidence interval 0.46-0.81], p = 0.001).

CONCLUSION

Sarcopenia is a strong risk factor for treatment discontinuation and reduced progression-free survival in glioblastoma patients. We propose that sarcopenic patients should receive intensified supportive care during radiotherapy and during follow-up as well as expedited access to palliative care.

Influence of weight-adjusted contrast enhancement on computed tomography-derived skeletal muscle measures: a retrospective proof-of-concept comparative study between Danish females and males

BACKGROUND

Computed tomography (CT) has an underutilized potential for evaluating body composition in clinical settings. Often conducted with intravenous contrast (IVC), CT scans yield unused body composition data due to unclear effects on skeletal muscle area (SMA), skeletal muscle index (SMI), and muscle density (SMD).

OBJECTIVES

This study investigates whether weight-adjusted IVC influences SMA, SMI, and SMD differently in females and males compared with noncontrast abdominal CT. In addition, the study explores associations between contrast and noncontrast-assessed SMA, SMI, SMD, and demographic factors.

METHODS

A comparative observational retrospective study was conducted on Danish patients who underwent consecutive 4-phased contrast-enhanced abdominal CT scans (noncontrast, arterial, venous, and late venous phases). Muscle measures were evaluated using validated semiautomated threshold-based software by 3 independent raters.

RESULTS

The study included 72 patients (51 males and 21 females) with a mean age of 59 (55 and 62) y. Weight-adjusted IVC increased SMA by ≤3.28 cm2 (95% confidence interval [CI]: 2.58, 3.98) corresponding to 2.4% (1.8, 2.9) in the late venous phase compared with noncontrast CT. Analysis between sexes showed no difference in the effects of IVC on SMA and SMI between females and males. However, females exhibited a higher increase in SMD during the venous by a mean of 1.7 HU (0.9; 2.5) and late venous phases with a mean HU of 1.80 (1.0; 2.6) compared with males. Multivariate regression analysis indicated an association between the differences in SMD and sex during venous (-1.38, 95% CI: -2.48, -0.48) and late venous phases (-1.23, 95% CI: -2.27, -0.19).

CONCLUSIONS

Weight-adjusted IVC leads to increased SMA, SMI, and SMD. Although SMA and SMI differences were consistent across the sexes, females exhibited a significantly higher SMD increase than males in the venous and late venous phases. Further investigations are necessary to determine the applicability of SMD as a muscle quality proxy in IVC CT scans.

Early Postoperative Patient-Reported Outcomes of Sarcopenia Versus Nonsarcopenia in Patients Undergoing Video-Assisted Thoracoscopic Surgery for Lung Cancer

BACKGROUND

To compare early postoperative patient-reported outcomes between sarcopenic and nonsarcopenic patients undergoing video-assisted thoracoscopic surgery (VATS) for lung cancer.

METHODS

The data used in this study were acquired from a longitudinal prospective study (CN-PRO-Lung 1) between November 2017 and January 2020. Skeletal muscle index was measured at L3 vertebral level on preoperative computed tomography to identify sarcopenia based on an established threshold. Symptoms severity and status of functional impairments were reported as proportions of patients with clinically relevant moderate-to-severe scores on 0-10 scales, which were measured by using the MD Anderson Symptom Inventory-Lung Cancer at baseline, daily postoperative hospitalization, and weekly after discharge up to 4 weeks. Symptom severity, functional status, and postoperative clinical outcomes were compared between the sarcopenia and nonsarcopenia groups.

RESULTS

This study included 125 patients undergoing VATS for lung cancer. Sarcopenia was identified in 34 (27.2%) patients. Sarcopenic patients reported more moderate-to-severe pain (P = 0.002) at discharge and more moderate-to-severe fatigue (P = 0.027) during the 4 weeks after discharge. Besides, sarcopenic patients had a longer recovery time from both pain (P = 0.002) and fatigue (P = 0.007) than nonsarcopenic patients. Meanwhile, no significant between-group difference was found in the postoperative clinical outcomes (all P > 0.05).

CONCLUSIONS

Sarcopenic patients undergoing VATS for lung cancer may have more pain and fatigue, as well as longer symptoms recovery time than nonsarcopenic patients during the early postoperative period.

Thoracic sarcopenia measured by Hounsfield unit average calculation predicts morbidity and mortality in coronary artery bypass grafting

OBJECTIVES

The aim of the study was to investigate the potential prognostic role of preoperative measurement of erector spinae myosteatosis with Hounsfield unit average calculation as a marker for sarcopenia and frailty in patients undergoing coronary bypass surgery.

METHODS

Preoperative computer tomography-derived measurements of 479 consecutive patients undergoing coronary bypass surgery between January 2017 and December 2019 were retrospectively performed. The erector spinae muscle at the level of the 12th vertebra was manually outlined bilaterally on the axial computer tomography slices and Hounsfield unit average calculation was performed. The lower quartile of muscle density values was defined as myosteatotic and thus sarcopenic. Sarcopenic (n = 121) versus non-sarcopenic patients (n = 358) were compared regarding postoperative morbidity and short- and long-term mortality. Results were adjusted for age, body mass index, atrial fibrillation and hypertension using inverse probability weighting.

RESULTS

Sarcopenia was associated with higher 30-day mortality (4.1% vs 0.8%; P = 0.012), mid-term mortality after 1 year (9.3% vs 3.1%; P = 0.047) and 2 years (10.8% vs 4.2%; P = 0.047). Long-term mortality (5 years) was 20.8% for sarcopenic and 13.0% for non-sarcopenic patients but was not found to be significantly different (P = 0.089). Sarcopenia was associated with higher rates of reintubation (7.5% vs 1.1%; P < 0.001), sternal wound infections (7.5% vs 2.8%; P = 0.039) and acute kidney injury requiring haemodialysis (2.5% vs 0.4%; P = 0.021).

CONCLUSIONS

In patients undergoing coronary bypass surgery, sarcopenia was associated with increased short-term mortality, mid-term mortality and morbidity. The measurement of erector spinae myosteatosis could be an easy and useful parameter in preoperative risk assessment.