Skeletal Muscle Area Research Articles

Racial differences in body composition and survival among older adults with gastrointestinal malignancies

IntroductionMuscle and adipose tissue measures can be quantified from routinely obtained computed tomography (CT) images and are predictors of chemotherapy-related toxicities and survival among patients with gastrointestinal (GI) malignancies. Most studies to date have consisted of predominantly White patients, and the role of body composition among minoritized racial groups is unknown. We examined racial differences in body composition and survival among patients with GI malignancies. Materials and MethodsThis was a prospective cohort study of patients with GI malignancies. Single slices of axial CT images from L3 segments were analyzed using Slice-O-Matic software. The skeletal muscle area (cm2) was divided by height to obtain the skeletal muscle index (SMI, cm2/m2). Skeletal muscle radiodensity (SMD) in Hounsfield units (HU) was used for muscle composition. We compared body composition parameters between non-Hispanic (NH)-White and NH-Black participants. Cox models were used to examine the impact of body composition on survival. We proposed new race-specific cutoffs for body composition using optimal stratification. ResultsFive hundred forty patients were included, of which 24% were NH-Black. In Cox models stratified by race, each 5 cm2/m2 decrease in SMI was associated with increase in risk of all-cause mortality in NH-Black patients (hazard ratio [HR] 1.25; 95% confidence interval [CI] 1.04–1.49 p = 0.02). With the existing cut points, neither sarcopenia nor myosteatosis was associated with worse survival. Using a new cutoff for sarcopenia in NH-Black patients, NH-Black patients with sarcopenia (HR 2.31 95%CI 1.10–4.88 p = 0.03) and myosteatosis (HR 2.63 95% CI 1.25–5.53 p = 0.01) had worse survival. DiscussionNH-Black older patients with GI cancers and sarcopenia or myosteatosis have worse overall survival.

Abstract P187: Associations of Body Composition, Inflammation, and Lipids: The Multi-Ethnic Study of Atherosclerosis

Background: Prior evidence has linked inflammation with myopenic obesity (MO), a high cardiometabolic risk body composition phenotype characterized by low muscle and high fat mass. Inflammation may also alter lipid metabolism. This study aimed to examine the association between MO and lipids and whether inflammation is one potential mediator of their complex relationship. Methods: We conducted a cross-sectional analysis of 1,421 Multi-Ethnic Study of Atherosclerosis participants with abdominal computed tomography body composition, lipid, and inflammatory marker measurements. The ratio of total skeletal muscle area to total adipose tissue area (SM/AT) at L3-4 was used to identify MO (lowest sex-stratified tertiles of <0.52 in men and <0.44 in women). Principal component analysis was used to reduce six inflammatory markers by patterns of covariation. Parallel mediation analysis was conducted to examine whether the inflammatory components mediated the relationship between SM/AT and lipids, acknowledging the limitations of cross-sectional data. Results: The sample’s mean age was 64±10 years, 52.4% were female, and 42.1% were Caucasian. Participants with MO (n=474), compared to those without (n=947), had lower high-density lipoprotein cholesterol (HDL-C; 49±13 vs. 54±16, p<0.001), higher remnant cholesterol (RC; 28±13 vs. 24±13, p<0.001), and similar low-density lipoprotein cholesterol (LDL-C; 110±32 vs. 113±30, p=0.073). All inflammatory markers were higher in MO (p≤0.002). Parallel mediation analysis showed significant direct effects between SM/AT and both HDL-C and RC, which were mediated by component 1 but not component 2. There was no significant direct or indirect effect between SM/AT and LDL-C (Table 1). Conclusion: Participants with MO exhibited elevated levels of inflammation and unfavorable lipid profiles. Two inflammatory components were identified, one of which (IL-6, CRP, fibrinogen, and leptin) partially mediated the relationship of SM/AT with HDL-C and RC.

Cardiovascular Imaging-Derived Skeletal Muscle Mass Correlates With Fitness and Survival in Patients With Univentricular Circulation.

Aims This study aims to retrospectively quantify skeletal muscle mass from cardiovascular imaging studies in total cavopulmonary connection (TCPC) patients and to correlate calculated muscle mass with clinical outcomes. Materials and methods Ninety-one TCPC patients at a mean age of 24.0 ±5.5 years (37 women; 40.7%) who underwent chest computed tomography (CT) or cardiac magnetic resonance imaging (MRI) as part of their follow-up were identified in a single-center database. The cross-sectional skeletal muscle index (SMI) at the Th4 and Th12 levels was calculated from CT images, and the dorsal skeletal muscle area (SMA) at the Th12 level was measured from an MRI. Results Calculated SMI at Th12 level was 38.0 (34.5; 42.0) cm2.m-2 or 89.6 (81.9; 101.6) % of predicted values. The median follow-up from CT was 5.9 (3.1; 8.5) years, and the composite endpoint (death N=5, heart transplant N=6) was reached in a total of 11 (26.8%) patients. Patients with SMI (Th12) less than 90% of predicted values had a hazard ratio of 5.8 (95% CI: 1.2; 28.3) (p=0.03) for endpoint achievement. In the MRI group, dorsal SMA at the Th12 level was 27.6 ±5.1 cm2 in men and 20.0 ±5.8 cm2 in women. Correlations were found between SMA/kg and peak oxygen uptake (VO2peak) (r=0.48, p=0.0005) and fat-free mass (r=0.63, p<0.0001), respectively. Conclusions A low SMI at the Th12 level was associated with a higher risk of death or cardiac transplantation. Evaluation of skeletal muscle mass using cardiovascular imaging methods allows rapid identification of individuals at risk of sarcopenia.

Sarcopenia accompanied by systemic inflammation can predict clinical outcomes in patients with head and neck cancer undergoing curative therapy.

Evaluation of sarcopenia accompanied by systemic inflammation status is a more beneficial prognostic marker than sarcopenia alone in various cancers. However, few studies have focused on this combination in patients with head and neck squamous cell cancer (HNSCC). In this study, we investigated how the combination of sarcopenia and systemic inflammation could affect survival in patients with HNSCC. Moreover, we explored which systemic inflammation markers could be better prognostic indicators when accompanied by sarcopenia. We retrospectively reviewed the medical records of patients with HNSCC treated between 2012 and 2016. Sarcopenia was defined by the skeletal muscle area measured on a computed tomography image slice at the level of the third cervical vertebra. The neutrophil/lymphocyte, platelet/lymphocyte, and lymphocyte/monocyte ratios (NLR, PLR, and LMR, respectively) were used as systemic inflammation markers that were combined with sarcopenia to evaluate prognosis. A total of 100 patients were enrolled, and 71 patients were considered sarcopenia. Patients with sarcopenia had significantly lower LMR and higher NLR and PLR. They also showed worse overall survival (OS) and progression-free survival (PFS). The comparative assessment of multiple combination patterns of sarcopenia and systemic inflammation indices proved that sarcopenia plus LMR considered as most reliable indicator for prognosis in HNSCC patients. Sarcopenia plus low LMR was a significantly poor prognostic factor both for OS and PFS with greater HR values than sarcopenia alone. The combination of sarcopenia and LMR was considered the most sensitive prognostic factor in patients with HNSCC, suggesting it might be beneficial for identifying poor outcome risks.

Visceral obesity and sarcopenia as predictors of efficacy and hematological toxicity in patients with metastatic breast cancer treated with CDK 4/6 inhibitors.

We aimed to investigate whether visceral adipose tissue (VAT), subcutaneous adipose tissue (SAT), and skeletal muscle area (SMA) index are predictive for efficacy and hematological toxicity in ER+HER2-metastatic breast cancer (BC) patients who received CDK 4/6 inhibitors. This retrospective cohort study analyzed 52 patients who were treated with CDK 4/6 inhibitors between January 2018 and February 2021. The values of VAT, SAT, SMA indices and hematological parameters were noted before the start, at the third and sixth months of this treatment. The skeletal muscle area (SMA) and adipose tissue measurements were calculated at the level of the third lumbar vertebra. A SMA-index value of <40cm2/m2 was accepted as the threshold value for sarcopenia. Patients with sarcopenia had a worse progression-free survival (PFS) compared to patients without sarcopenia (19.6 vs. 9.0months, p=0.005). Patients with a high-VAT-index had a better PFS (20.4 vs. 9.3months, p=0.033). Only the baseline low-SMA- index (HR: 3.89; 95% CI: 1.35-11.25, p=0.012) and baseline low-VAT-index (HR: 2.15; 95% CI: 1.02-4.53, p=0.042) had significantly related to poor PFS in univariate analyses. The low-SMA-index was the only independent factor associated with poor PFS (HR: 3.99; 95% CI: 1.38-11.54, p=0.011). No relationship was observed between body composition parameters and grade 3-4 hematological toxicity. The present study supported the significance of sarcopenia and low visceral adipose tissue as potential early indicators of poor PFS in patients treated with CDK 4/6 inhibitors.

The identification of an optimal body size parameter to adjust skeletal muscle area on chest CT in COVID-19 patients.

The most efficient way to adjust skeletal muscle area (SMA) derived from chest CT to body size remains unclear. We hypothesized that vertebral body area (VBA) measurement would allow such efficient adjustment. We conducted a retrospective observational study of chest CT imaging in a cohort of critically ill COVID-19 patients. We measured paravertebral SMA at T5 level and T5 vertebral body anteroposterior length, width, and area. We used linear regression and multivariable modelling to assess the association of VBA with SMA. In 48 COVID-19 patients in ICU, T5 VBA could be easily derived from simple width and anteroposterior length linear measurements. T5 VBA (measured manually or estimated from width and length) performed similarly to height (R2 of 0.22) as an adjustment variable for SMA, with R2 of 0.23 and 0.22, respectively. Gender had the strongest correlation with SMA (R2 = 0.28). Adding height or age to a model using gender and VBA did not improve correlation. Gender and estimated VBA from simple linear measurements at T5 level on CT images can be utilized for adjustment of SMA without the need for height. Validation of these findings in larger cohorts of critically ill patients is now needed.

Achievement of adequate nutrition contributes to maintaining the skeletal muscle area in patients with sepsis undergoing early mobilization: a retrospective observational study

BackgroundThe onset of muscle loss in critically ill patients, known as intensive care unit-acquired weakness (ICU-AW), worsens their outcomes. Preventing muscle loss, which begins in the early phase of critical illness, is crucial in patient care. Adequate nutrition management may contribute to maintaining muscles; however, its evidence in patients with sepsis is insufficient. This study aimed to analyze the association between energy achievement rate in the first 7-days of critical care and muscle area changes evaluated by computed tomography (CT).MethodsThis was a retrospective observational study. Patients with sepsis admitted to the intensive care (ICU) of a tertiary care hospital in Japan were included. They were divided into three groups according to tertiles of the first 7-day energy achievement rate calculated using administered energy doses and basement energy expenditure. Skeletal muscle area (SMA) and changes in SMA were determined by CT on ICU admission and within days 7–10 of ICU admission. SMA maintenance was defined as SMA change ≥ 100%. Logistic regression analyses were performed to analyze the association of energy achievement rate with SMA changes (primary outcome) and in-hospital 28-day mortality (secondary outcome).ResultsPatients (n = 93) were classified into low, middle, and high groups according to their 7-day energy achievement rate (median rates, 16.8%, 38.8%, and 73.4%, respectively). The CT scans showed that SMA decreased between the CT scans in the low and middle groups, whereas it was maintained in the high group (median changes, -8.5%, -11.7%, and 2.8%, respectively). Univariate and multivariate logistic regression analyses showed that high energy achievement rate was significantly associated with SMA maintenance (reference, middle energy achieved group; univariate, odds ratio [95% confidence interval] 6.23 [2.04–19.10], P = 0.0013; multivariate, odds ratio [95% confidence interval] 5.92 [1.90–18.40], P = 0.0021). There was no significant difference in the association between energy achievement rate and mortality among the three groups.ConclusionsOur study found that a fulfillment of energy achievement in the first 7 days of hospitalization was associated with maintenance of muscle area. Thus, satisfying adequate energy should be considered even in patients with sepsis.

Impact of preoperative subcutaneous adipose, visceral adipose and skeletal muscle on the outcomes of the oldest-old colorectal cancer patients after surgery

BackgroundColorectal cancer (CRC) is one of the most common tumors worldwide, with rising numbers of elderly patients affected. Nutritional status significantly influences tumor prognosis. We aimed to investigate the association of subcutaneous and visceral adipose tissue and skeletal muscle mass with the prognosis of the oldest-old patients with CRC, after surgery. PatientsWe retrospectively reviewed 210 patients >75 years who underwent surgical treatment at the Department of Gastrointestinal Surgery, Beijing Hospital, between December 2010 and December 2020. MaterialsSubcutaneous adipose, visceral adipose, and skeletal muscle areas were measured using BMI_CT. The cut-off values of the CT measurements were then confirmed using receiver operating characteristic (ROC) curve analysis. ResultsSubcutaneous adipose tissue index (SATI), visceral adipose tissue index (VATI), and total adipose tissue index (TATI) were significantly associated with sex and BMI. Notably, the oldest-old CRC patients with high SATI, VATI, and TATI scores exhibited significantly higher rates of wound complications and reduced postoperative hospitalization durations. Intriguingly, patients with high VATI and TATI demonstrated significantly better 5-year Overall survival (OS), Cancer-specific survival (CSS), and Disease-free survival (DFS) than patients in the other groups. Similar results were observed in patients with a high visceral-to-subcutaneous fat ratio (VSR) and skeletal muscle index (SMI) scores. ConclusionSignificantly improving skeletal muscle content while concurrently managing the total adipose content, especially visceral adipose tissue, may aid in extending the survival time of oldest-old patients with CRC after surgery.

Influence of nutritional status and body composition on postoperative events and outcome in patients treated for primary localized retroperitoneal sarcoma.

Retroperitoneal sarcomas (RPS) are rare tumours of mesenchymal origin, commonly presented as a large tumour mass at time of diagnosis. We investigated the impact of body composition on outcome in patients operated on for primary localized RPS. We retrospectively analysed data for all patients operated on for primary RPS at our institution between 1999 and 2020. Preoperative skeletal muscle area (SMA), visceral and subcutaneous adipose tissue area (VAT and SAT) and muscle radiation attenuation (MRA) were calculated using computed tomography scans at the level of third lumbar vertebra. European Working Group on Sarcopenia in Older People (EWGSOP2) criteria were applied to define myopenia. Using maximum log-rank statistic method we determined the optimal cut-off values of body composition parameters. Myosteatosis was defined based on determined MRA cut-offs. In total 58 patient were eligible for the study. With a median follow-up of 116 months, the estimated 5-year overall survival (OS) and local-recurrence free survival (LRFS) were 66.8% and 77.6%, respectively. Patients with myopenia had significantly lower 5-year OS compared to non-myopenic (p = 0.009). Skeletal muscle index and subcutaneous adipose tissue index predicted LRFS on univariate analysis (p = 0.052 and p = 0.039, respectively). In multivariate analysis high visceral-to-subcutaneous adipose tissue area ratio (VSR) independently predicted higher postoperative complication rate (89.2% vs. 10.8%, p = 0.008). Myosteatosis was associated with higher postoperative morbidity. Myopenia affected survival, but not postoperative outcome in RPS. Visceral obesity, VSR (> 0.26) and myosteatosis were associated with higher postoperative morbidity. VSR was better prognostic factor than VAT in RPS.

Abdominal Body Composition Reference Ranges and Association With Chronic Conditions in an Age- and Sex-Stratified Representative Sample of a Geographically Defined American Population.

Body composition can be accurately quantified from abdominal computed tomography (CT) exams and is a predictor for the development of aging-related conditions and for mortality. However, reference ranges for CT-derived body composition measures of obesity, sarcopenia, and bone loss have yet to be defined in the general population. We identified a population-representative sample of 4900 persons aged 20 to 89 years who underwent an abdominal CT exam from 2010 to 2020. The sample was constructed using propensity score matching an age and sex stratified sample of persons residing in the 27-county region of Southern Minnesota and Western Wisconsin. The matching included race, ethnicity, education level, region of residence, and the presence of 20 chronic conditions. We used a validated deep learning based algorithm to calculate subcutaneous adipose tissue area, visceral adipose tissue area, skeletal muscle area, skeletal muscle density, vertebral bone area, and vertebral bone density from a CT abdominal section. We report CT-based body composition reference ranges on 4649 persons representative of our geographic region. Older age was associated with a decrease in skeletal muscle area and density, and an increase in visceral adiposity. All chronic conditions were associated with a statistically significant difference in at least one body composition biomarker. The presence of a chronic condition was generally associated with greater subcutaneous and visceral adiposity, and lower muscle density and vertebrae bone density. We report reference ranges for CT-based body composition biomarkers in a population-representative cohort of 4649 persons by age, sex, body mass index, and chronic conditions.

Tumor-Derived Sarcopenia Factors Are Diverse in Different Tumor Types: A Pan-Cancer Analysis.

Cancer-associated muscle wasting is a widespread syndrome in people with cancer and is characterized by weight loss and muscle atrophy, leading to increased morbidity and mortality. However, the tumor-derived factors that affect the development of muscle wasting and the mechanism by which they act remain unknown. To address this knowledge gap, we aimed to delineate differences in tumor molecular characteristics (especially secretion characteristics) between patients with and without sarcopenia across 10 tumor types from The Cancer Genome Atlas (TCGA). We integrated radiological characteristics from CT scans of TCGA cancer patients, which allowed us to calculate skeletal muscle area (SMA) to confirm sarcopenia. We combined TCGA and GTEx (The Genotype-Tissue Expression) data to analyze upregulated secretory genes in 10 tumor types compared with normal tissues. Upregulated secretory genes in the tumor microenvironment and their relation to SMA were analyzed to identify potential muscle wasting biomarkers (560 samples). Meanwhile, their predictive values for patient survival was validated in 3530 samples in 10 tumor types. A total of 560 participants with transcriptomic data and SMA were included. Among those, 136 participants (24.28%) were defined as having sarcopenia based on SMA. Enrichment analysis for upregulated secretory genes in cancers revealed that pathways associated with muscle wasting were strongly enriched in tumor types with a higher prevalence of sarcopenia. A series of SMA-associated secretory protein-coding genes were identified in cancers, which showed distinct gene expression profiles according to tumor type, and could be used to predict prognosis in cancers (p value ≤ 0.002). Unfortunately, those genes were different and rarely overlapped across tumor types. Tumor secretome characteristics were closely related to sarcopenia. Highly expressed secretory mediators in the tumor microenvironment were associated with SMA and could affect the overall survival of cancer patients, which may provide a valuable starting point for the further understanding of the molecular basis of muscle wasting in cancers. More importantly, tumor-derived pro-sarcopenic factors differ across tumor types and genders, which implies that mechanisms of cancer-associated muscle wasting are complex and diverse across tumors, and may require individualized treatment approaches.

Comparison of bioelectrical impedance analysis and computed tomography for the assessment of muscle mass in patients with gastric cancer

BackgroundLow muscle mass was significantly correlated with poor clinical outcomes in cancer patients. This study aimed to compare the differences between bioelectrical impedance analysis (BIA) and computed tomography (CT) in measuring skeletal muscle mass and detecting low muscle mass in patients with gastric cancer (GC). MethodThis cross-sectional study included a total of 302 consecutive patients diagnosed with GC at our institution from October 2021 to March 2023. CT images were analyzed at the L3 level to obtain the cross-sectional area of skeletal muscle, which was subsequently used for calculating whole-body skeletal muscle mass via the Shen equation and skeletal muscle tissue density. BIA was utilized to measure skeletal muscle mass using the manufacturer's proprietary algorithms. Skeletal muscle mass (kg) was divided by height squared (m2) to obtain skeletal muscle index (SMI, kg/m2). Pearson's correlation coefficient was performed to assess the correlation between SMI measured by BIA and CT. The agreement between the two methods was assessed using Bland-Altman analyses. The clinically acceptable agreement was defined as the 95% limits of agreement (LOA) for the percentage bias falling within ± 10%. The area under the receiver operating characteristic curve (AUC) was used to evaluate the performance of BIA in identifying low muscle mass. ResultsA total of 59 patients (19.5%) were identified as having low muscle mass based on CT analysis, whereas only 19 patients (6.3%) met the criteria for low muscle mass according to BIA analysis. BIA-measured SMI showed a strong positive correlation with CT-measured SMI in all patients (r = 0.715, P < 0.001). With Bland-Altman analysis, there was a significant mean bias of 1.18 ± 0.96 kg/m2 (95% CI 1.07–1.29, P < 0.001) between SMI measured by BIA and CT. The 95% LOA for the percentage bias ranged from -7.98 to 33.92%, which exceeded the clinically acceptable range of ± 10%. A significant difference was observed in the mean bias of SMI measured by BIA and CT between patients with and without GLIM malnutrition (1.42 ± 0.91 kg/m2 versus 0.98 ± 0.96 kg/m2, P < 0.001). The cut-off values for BIA-measured SMI in identifying low muscle mass using CT as the reference were 10.11 kg/m2 for males and 8.71 kg/m2 for females (male: AUC = 0.840, 95% CI: 0.772–0.908; female: AUC = 0.721, 95% CI: 0.598–0.843). ConclusionsDespite a significant correlation, the values of skeletal muscle mass obtained BIA and CT cannot be used interchangeably. The BIA method may overestimate skeletal muscle mass in GC patients compared to CT, especially among those with GLIM malnutrition, leading to an underestimation of low muscle mass prevalence.

Surgical decision making in locally advanced esophageal adenocarcinoma.

299 Background: Trimodality therapy consisting of chemoradiation followed by surgery (CRT+S) is considered optimal therapy for locally advanced adenocarcinoma (ACA) of the esophagus, yet the morbidity of surgery is substantial. We used CT-derived body composition and age to categorize patients into perioperative surgical mortality risk groups. Among patients with locally advanced esophageal ACA who were treated with CRT, the benefit of surgery (CRT+S) was examined in low-risk and high-risk patients. Methods: The association of perioperative mortality with age and skeletal muscle gauge (SMG) was estimated using a group of 290 patients undergoing esophagectomy of various histologies between 2010 and 2022. CT scans were analyzed to calculate SMG as the product of skeletal muscle area and skeletal muscle density. Logistic regression models were used to evaluate the association of age and SMG with 90-day surgical mortality. Patients were classified based on their predicted probability of 90 day mortality into low and high risk groups, where high risk was defined as the highest-risk 25% of patients. This model was then applied to the study cohort of patients with ACA. Log-rank tests were used to compare overall survival by treatment (CRT vs CRT+S) in the high risk and low risk groups. Results: Of 316 patients with locally advanced ACA treated with CRT, 254 underwent surgery (CRT+S). 90-day post operative mortality in the CRT+S group was 5.1%. 74 patients were categorized as high-risk and 242 as low-risk. Among low-risk patients, 213 (88.0%) were treated with surgery (CRT+S) and had a significantly longer overall survival compared to CRT (p&lt;0.0001), with median survival of 40.6mo (95% CI 32.3, 55.5) in the CRT+S group and 17.3mo (95% CI 13.3, 36.4) in the CRT group. Among 74 high risk patients, 41 (55.4%) were treated with surgery. We did not find a difference in overall survival between the surgical group (CRT+S) and the group treated with CRT alone (p=0.34). The median survival was 27.4mo (95% CI 15.8, 32.9) in the CRT group compared to 23.0mo (95% CI 14.7, 54.4) in the CRT+S group. Conclusions: Our retrospective study demonstrated that for low-risk patients with adenocarcinoma of the esophagus, there is a survival benefit to the addition of surgery. Conversely, we failed to detect a survival benefit to the addition of surgery in the highest-risk quartile of patients. Measurement of body composition may help identify a high-risk subset of patients with locally advanced adenocarcinoma of the esophagus who may benefit from forgoing surgery after chemoradiation.

Body composition and postoperative outcomes after minimally invasive esophagectomy.

300 Background: Esophagectomy is a complex operation associated with significant morbidity for even fit, healthy patients. Prior studies have utilized hand grip strength or muscle mass to predict postoperative esophagectomy outcomes. This study however, used skeletal muscle gauge (SMG), a CT-derived body composition measure, along with age, to classify patients into groups to summarize perioperative surgical mortality after minimally invasive esophagectomy. Methods: A total of 396 patients undergoing minimally invasive esophagectomy between 2010 and 2022 were identified. Preoperative CT scans at the L3 vertebral level were analyzed to calculate skeletal muscle gauge (SMG) as the product of skeletal muscle area and skeletal muscle density. Patient demographics, histology, treatment, and outcomes including anastomotic leak, pneumonia, prolonged ventilation, discharge destination, 30-day readmission, and 90-day mortality were collected. Patients were grouped into quartiles of SMG and by age (≥75 and &lt;75 years). 90-day postoperative mortality for the high risk group in the bottom SMG quartile (Q1) was compared to the low-risk group in the top 3 quartiles (Q234). Results: Mean age was 62.8 years (SD 10.4). Patients were 84.4% male with 87.4% White, 10.6% Black, 1.8% Hispanic, and 0.3% Asian. Histologically, 86.4% of patients had adenocarcinoma while 11.4% had squamous cell carcinoma. Anastomotic leak occurred in 8.1%, pneumonia in 16.7%, ventilation greater than 48 hours in 20.7%, and discharge to home in 82.1% of patients. 30-day readmission occurred in 16.4% and 90-day mortality in 6.1% of patients. 8 patients did not have CT scans available. Analysis of 90-day mortality as a function of age &gt;75 and SMG risk group showed 33.3% mortality among patients &gt;75 in Q1 for SMG, 9.6% for patients &lt;75 in Q1 for SMG, 5.6% for patients &gt;75 in Q234 for SMG, and 2.2% in 264 patients &lt;75 in Q234 for SMG for subjects who had available scan data (n = 388). Conclusions: As expected, patients with older age and lower SMG have higher mortality after esophagectomy compared to younger patients with higher SMG. Patients who are &gt;75 years old and in the bottom SMG quartile represent a small group (27/388 = 7% of the total) which are identified as a high-risk group with a mortality of 33.3%. This study identifies a small subset of patients whose risk of surgery may outweigh the benefit, particularly in patients already treated with chemoradiation. Preoperative body composition, as measured by SMG, in combination with age can be used to predict postoperative mortality after minimally invasive esophagectomy and guide treatment decisions. [Table: see text]

Body composition measurements and clinical outcomes in patients with resectable pancreatic adenocarcinoma – analysis from SWOG S1505

Sarcopenic obesity and muscle attenuation have been associated with survival in patients with borderline resectable and advanced pancreatic ductal adenocarcinoma (PDA); however, these relationships are unknown for patients with resectable PDA. This study examined the associations between skeletal muscle and adipose tissue as measured on baseline computed tomography (CT) and the overall survival (OS) of participants with resectable PDA in a secondary analysis of the Southwest Oncology Group S1505 clinical trial (identifier: NCT02562716). The S1505 phase II clinical trial enrolled patients with resectable PDA who were randomized to receive modified FOLFIRINOX or gemcitabine and nab-paclitaxel as perioperative chemotherapy, followed by surgical resection. Baseline axial CT images at the L3 level were analyzed with externally validated software, and measurements were recorded for skeletal muscle area and skeletal muscle density, visceral adipose tissue area (VATA) and density, and subcutaneous adipose tissue area and density. The relationships between CT metrics and OS were analyzed using Cox regression models, with adjustment for baseline participant characteristics. Of 98 eligible participants with available baseline abdominal CT, 8 were excluded because of imaging quality (eg, orthopedic hardware), resulting in 90 evaluable cases: 51 men (57.0%; mean age, 63.2 years [SD, 8.5]; mean body mass index [BMI], 29.3kg/m2 [SD, 6.4]), 80 White (89.0%), 6 Black (7.0%), and 4 unknown race (4.0%). Sarcopenia was present in 32 participants (35.9%), and sarcopenic obesity was present in 10 participants (11.2%). Univariable analyses for the 6 variables of interest indicated that the standardized mean difference (hazard ratio [HR], 0.75; 95% CI, 0.57-0.98; P=.04) was statistically significantly associated with OS. In models adjusted for sex, race, age, BMI, performance score, contrast use, sarcopenia, and sarcopenic obesity, VATA was statistically significantly associated with OS (HR, 1.58; 95% CI, 1.00-2.51; P=.05). No difference was observed in OS between participants according to sarcopenic obesity or sarcopenia categories. The median OS estimates were 25.1 months for participants without sarcopenic obesity, 18.6 months for participants with sarcopenic obesity, 23.6 months for participants without sarcopenia, and 27.9 months for participants with sarcopenia. This was the first study to systematically evaluate body composition parameters in a prospective multicenter trial of patients with resectable PDA who received perioperative chemotherapy. Visceral adipose tissue was associated with survival; however, there was no association between OS and sarcopenia or sarcopenic obesity. Further studies should evaluate these findings in more detail.

Association of Muscle Mass Loss with Diabetes Development in Liver Transplantation Recipients.

Post-transplant diabetes mellitus (PTDM) is one of the most significant complications after transplantation. Patients with end-stage liver diseases requiring transplantation are prone to sarcopenia, but the association between sarcopenia and PTDM remains to be elucidated. We aimed to investigate the effect of postoperative muscle mass loss on PTDM development. A total of 500 patients who underwent liver transplantation at a tertiary care hospital between 2005 and 2020 were included. Skeletal muscle area at the level of the L3-L5 vertebrae was measured using computed tomography scans performed before and 1 year after the transplantation. The associations between the change in the muscle area after the transplantation and the incidence of PTDM was investigated using a Cox proportional hazard model. During the follow-up period (median, 4.9 years), PTDM occurred in 165 patients (33%). The muscle mass loss was greater in patients who developed PTDM than in those without PTDM. Muscle depletion significantly increased risk of developing PTDM after adjustment for other confounding factors (hazard ratio, 1.50; 95% confidence interval, 1.23 to 1.84; P=0.001). Of the 357 subjects who had muscle mass loss, 124 (34.7%) developed PTDM, whereas of the 143 patients in the muscle mass maintenance group, 41 (28.7%) developed PTDM. The cumulative incidence of PTDM was significantly higher in patients with muscle loss than in patients without muscle loss (P=0.034). Muscle depletion after liver transplantation is associated with increased risk of PTDM development.

Skeletal Muscle Area on CT: Determination of an Optimal Height Scaling Power and Testing for Mortality Risk Prediction.

BACKGROUND. Sarcopenia is commonly assessed on CT by use of the skeletal muscle index (SMI), which is calculated as the skeletal muscle area (SMA) at L3 divided by patient height squared (i.e., a height scaling power of 2). OBJECTIVE. The purpose of this study was to determine the optimal height scaling power for SMA measurements on CT and to test the influence of the derived optimal scaling power on the utility of SMI in predicting all-cause mortality. METHODS. This retrospective study included 16,575 patients (6985 men, 9590 women; mean age, 56.4 years) who underwent abdominal CT from December 2012 through October 2018. The SMA at L3 was determined using automated software. The sample was stratified into two groups: 5459 patients without major medical conditions (based on ICD-9 and ICD-10 codes) who were included in the analysis for determining the optimal height scaling power and 11,116 patients with major medical conditions who were included for the purpose of testing this power. The optimal scaling power was determined by allometric analysis (whereby regression coefficients were fitted to log-linear sex-specific models relating height to SMA) and by analysis of statistical independence of SMI from height across scaling powers. Cox proportional hazards models were used to test the influence of the derived optimal scaling power on the utility of SMI in predicting all-cause mortality. RESULTS. In allometric analysis, the regression coefficient of log(height) in patients 40 years old and younger was 1.02 in men and 1.08 in women, and in patients older than 40 years old, it was 1.07 in men and 1.10 in women (all p < .05 vs regression coefficient of 2). In analyses for statistical independence of SMI from height, the optimal height scaling power (i.e., those yielding correlations closest to 0) was, in patients 40 years old and younger, 0.97 in men and 1.08 in women, whereas in patients older than 40 years old, it was 1.03 in men and 1.09 in women. In the Cox model used for testing, SMI predicted all-cause mortality with a higher concordance index using of a height scaling power of 1 rather than 2 in men (0.675 vs 0.663, p < .001) and in women (0.664 vs 0.653, p < .001). CONCLUSION. The findings support a height scaling power of 1, rather than a conventional power of 2, for SMI computation. CLINICAL IMPACT. A revised height scaling power for SMI could impact the utility of CT-based sarcopenia diagnoses in risk assessment.

Assessment of body composition-related imaging parameters indicative of sarcopenia in Chinese patients with Crohn's disease: correlation with disease severity and biologic efficacy.

To evaluate the prognostic value of body composition-related imaging parameters in assessing Crohn's disease (CD) severity and biological responses in Chinese patients. We retrospectively analyzed electronic medical records and Computed tomography (CT) images from 117 CD patients, including 90 with sarcopenia and 27 without. We calculated subcutaneous fat area (SFA), visceral fat area, skeletal muscle area (SMA), mesenteric fat index (MFI), skeletal muscle index (SMI), and muscle attenuation (MA). CD Activity Index (CDAI) score and Simple Endoscopic Score for CD (SES-CD) were used to evaluate inflammation and biologic efficacy. Correlation and comparative analyses were performed to determine associations between imaging parameters and clinical data. Receiver operating characteristic curve analysis evaluated the predictive performance of combined body composition indicators. Sarcopenia was associated with higher CDAI scores and lower body mass index, albumin, and hemoglobin levels but was not associated with SES-CD or rates of clinical/endoscopic remission or response to biologic therapy. SMI was inversely correlated with CDAI score and SES-CD and positively correlated with albumin and hemoglobin. Endoscopy responders had higher SMA, MFI, SMI, and MA than non-responders. SES-CD improvement was positively correlated with MFI and MA and negatively correlated with SFA. The combined analysis of SMI, MFI, and MA yielded an area under the curve of 0.743 for predicting endoscopic response to biologic therapies in CD patients. SMI may indicate CD severity, while MFI and MA could predict biologic response. Integrating multiple body composition parameters enhances treatment outcome evaluation, suggesting their potential utility in CD assessment.

Implications of Sarcopenia and Glucometabolism Parameters of Muscle Derived From Baseline and End-of-Treatment 18F-FDG PET/CT in Diffuse Large B-Cell Lymphoma.

We previously found that the incidence of sarcopenia increased with declining glucose metabolism of muscle in patients with treatment-naïve diffuse large B-cell lymphoma (DLBCL). This study aimed to investigate the relationship between sarcopenia and muscle glucometabolism using 18F-FDG PET/CT at baseline and end-of-treatment, analyze the changes in these parameters through treatment, and assess their prognostic values. The records of 103 patients with DLBCL (median 54 years [range, 21-76]; male:female, 50:53) were retrospectively reviewed. Skeletal muscle area at the third lumbar vertebral (L3) level was measured, and skeletal muscle index (SMI) was calculated to determine sarcopenia, defined as SMI < 44.77 cm²/m² and < 32.50 cm²/m² for male and female, respectively. Glucometabolic parameters of the psoas major muscle, including maximum standardized uptake value (SUVmax) and mean standardized uptake value (SUVmean), were measured at L3 as well. Their changes across treatment were also calculated as ΔSMI, ΔSUVmax, and ΔSUVmean; Δbody mass index was also calculated. Associations between SMI and the metabolic parameters were analyzed, and their associations with progression-free survival (PFS) and overall survival (OS) were identified. The incidence of sarcopenia was 29.1% and 36.9% before and after treatment, respectively. SMI (P = 0.004) was lower, and sarcopenia was more frequent (P = 0.011) at end-of-treatment than at baseline. The SUVmax and SUVmean of muscle were lower (P < 0.001) in sarcopenia than in non-sarcopenia at both baseline and end-of-treatment. ΔSMI was positively correlated with ΔSUVmax of muscle (P = 0.022). Multivariable Cox regression analysis showed that sarcopenia at end-of-treatment was independently negatively associated with PFS (adjusted hazard ratio [95% confidence interval], 2.469 [1.022-5.965]), while sarcopenia at baseline was independently negatively associated with OS (5.051 [1.453-17.562]). Sarcopenic patients had lower muscle glucometabolism, and the muscular and metabolic changes across treatment were positively correlated. Sarcopenia at baseline and end-of-treatment was negatively associated with the prognosis of DLBCL.

Evaluation of the Anatomical Cross-Sectional Area of Psoas Major Muscle Using an Ultrasound Imaging System Combined With an Inertial Measurement Unit: Improved Reliability in the US Using IMU-Based Positioning Techniques.

Introduction: Recently, ultrasound (US) imaging has been used to estimate the cross-sectional area of skeletal muscle, but the reliability is uncertain. To improve the reliability of the US, we investigated skeletal muscle thickness measurement using an inertial measurement unit (IMU) to determine the direction of US beam incidence based on posture angle information. In addition, we examined whether the anatomical cross-sectional area (ACSA) of muscle can be estimated from the muscle thickness measured using the US with the IMU. Methods: In Experiment 1, two examiners measured the right psoas major at the fourth lumbar vertebra level in 10 university students using the US with and without an IMU. The intraclass correlation coefficient (ICC) was used to examine intra- and inter-rater variability. In Experiment 2, the two examiners measured the muscle thickness of the right psoas major in 31 male subjects using the US with an IMU. In addition, the ACSA of this muscle was measured using MRI. Pearson's correlation coefficient was used to examine the relationship between muscle thickness and ACSA, and a single regression analysis was performed. Results: Both intrarater reliability ICC (1, 2) and inter-rater reliability ICC (2, 2) were higher when US was used with IMU compared to without IMU (Experiment 1). A significant positive correlation (r = 0.84, p < 0.01) was observed between muscle thickness and ACSA (Experiment 2). The regression equation was significant at R 2 = 0.71 (p < 0.01). Conclusion: Using an IMU during US measurement of the psoas major improves intra- and interexaminer reliability and can be used to estimate the ACSA of the muscle.