Approaches to Assessment of Muscle Mass and Myosteatosis on Computed Tomography: A Systematic Review

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.

Volumetric body composition analysis of the Cancer Genome Atlas reveals novel body composition traits and molecular markers Associated with Renal Carcinoma outcomes

Clinically, the body mass index remains the most frequently used metric of overall obesity, although it is flawed by its inability to account for different adipose (i.e., visceral, subcutaneous, and inter/intramuscular) compartments, as well as muscle mass. Numerous prior studies have demonstrated linkages between specific adipose or muscle compartments to outcomes of multiple diseases. Although there are no universally accepted standards for body composition measurement, many studies use a single slice at the L3 vertebral level. In this study, we use computed tomography (CT) studies from patients in The Cancer Genome Atlas (TCGA) to compare current L3-based techniques with volumetric techniques, demonstrating potential limitations with level-based approaches for assessing outcomes. In addition, we identify gene expression signatures in normal kidney that correlate with fat and muscle body composition traits that can be used to predict sex-specific outcomes in renal cell carcinoma.

Patients With Type 2 Diabetes Mellitus and Early Diabetic Kidney Disease Exhibit Lower Computed Tomography-measured Skeletal Muscle Attenuation Values: A Propensity Score-matched Study

OBJECTIVE

To investigate the association between computed tomography-measured quality characteristics of skeletal muscle (SM) and early diagnosis of diabetic kidney disease (DKD) in patients with type 2 diabetes mellitus (T2DM).

METHODS

This retrospective study included patients diagnosed with T2DM, with and without early DKD, between January 2019 and December 2021. To reduce potential bias, propensity score matching (PSM) was performed. The area and computed tomography attenuation values for SM and different abdominal adipose depots were measured. After PSM, logistic and multiple linear regression analyze were performed to analyse risk factors for early DKD.

RESULTS

A total of 267 patients were enrolled (mean age, 61.67 years ± 10.87; 155 men) and divided into two groups: T2DM with early DKD (n = 133); and T2DM without DKD (n = 134). After PSM, 230 patients were matched (T2DM with early DKD [n = 115]; and T2DM without DKD [n = 115]), with no statistical differences in general characteristics between the two groups (P > .05). In multivariate logistic regression analysis, high-density lipoprotein cholesterol (odds ratio [OR] 0.14; 95% confidence interval [CI] 0.04-0.49; P = .002), uric acid (OR 1.01; 95% CI 1.00-1.01; P = .006), and SM attenuation value (OR 0.94; 95% CI 0.90-0.98; P = .003) were independent risk factors for early DKD. Multiple linear regression analysis revealed significant correlations between SM attenuation value and cystatin C (β = -0.39, P = .004), urine albumin-to-creatinine ratio (β = -0.26, P = .026), and estimated glomerular filtration rate (β = 0.31 P = .009) after adjustment for confounders.

CONCLUSION

Patients with T2DM and lower SM attenuation values may exhibit a higher risk for early DKD than those with higher values, which provides a potential imaging biomarker for early DKD diagnosis.

CT-based sarcopenia assessment: Predicting outcomes in acute infection patients

In this retrospective cohort study, we investigated the prognostic value of sarcopenia evaluated by Computed Tomography (CT)-based indices for adverse hospitalization outcomes in patients with acute infections. We analyzed data from 225 patients admitted to the hospital for acute infections between 2019 and 2020. Patients who had undergone an abdominal CT scan either up to 1 month before or within the first 3 days of hospitalization were included. CT image analysis was used to evaluate skeletal muscle mass (by skeletal muscle index (SMI)) and muscle quality (by psoas muscle density, pMD). Low pMD was associated with higher in-hospital mortality (31% vs 11.4% p < 0.001) as well as higher longer-term mortality rates (p = 0.008 for 30 days and <0.001 for 90- and 1-year mortality). Low pMD remained an independent poor prognostic factor after controlling for confounders, with an adjusted odds ratio (aOR) of 2.74, (95% CI 1.33-5.67, p = 0.006) for 1-year mortality, and aOR of 2.61, (95% CI 1.23-5.55) for a prolonged hospital stay. Low SMI was associated with adverse outcomes, although this association was not independent after controlling for confounders. Notably, patients with both low SMI and pMD exhibited the poorest hospitalization outcomes: aOR for 1-year mortality 5.015 (95% CI 1.767-14.23, p = 0.002), and prolonged length of stay aOR 3.197, (95% CI 1.159-8.821, p = 0.025). CT-based muscle indices serve as independent prognostic factors in medical patients admitted with acute infection. Incorporating radiological assessments of sarcopenia into routine care for hospitalized patients with acute infection may enable risk stratification and early intervention in reversible conditions.

The Association Between Preoperative Sarcopenia and Sarcopenic Obesity and the Occurrence of Postoperative Complications in Patients Undergoing Pancreaticoduodenectomy for Periampullary Malignancies-A Literature Review

BACKGROUND

Sarcopenia and sarcopenic obesity, perceived as a reflection of cancer-induced cachexia, are often diagnosed in patients with periampullary malignancies. The pathophysiology of those conditions is multifactorial regarding the tumor microenvironment, immunological response, and the relationship to surrounding tissues.

METHODS

The PubMed and SCOPUS databases were systematically searched between November 2023 and December 2023. A total of 254 studies were primarily identified. Regarding the inclusion and exclusion criteria, 26 studies were finally included in the review.

RESULTS

Evaluated papers disclosed that sarcopenia was significantly associated with a higher incidence of postoperative complications, including pancreatic fistula (POPF) type B and C, with the odds ratio (OR) ranging from 2.65 (95%CI 1.43-4.93, p = 0.002) to 4.30 (95%CI 1.15-16.01, p < 0.03). Sarcopenic patients also suffered more often from delayed gastric emptying (DGE) with an OR of 6.04 (95%CI 1.13-32.32, p = 0.036). Infectious complications, postoperative hemorrhage, and intra-abdominal abscesses occurred more often in sarcopenic patients. Surgical complications were also noted more frequently when sarcopenic obesity was present. Preoperative nutritional prehabilitation seems to reduce the risk of postoperative complications. However, more prospective studies are needed.

CONCLUSIONS

Sarcopenia and sarcopenic obesity were associated with a higher incidence of multiple postoperative complications, including POPF (type B and C), DGE, hemorrhage, and infectious complications.

Effect of contrast phase on quantitative analysis of skeletal muscle and adipose tissue by computed tomography

OBJECTIVES

Significant variability exists in the contrast phases applied during computed tomography (CT) studies when assessing morphometric measurements of muscle area (CT-assessed sarcopenia) and density (CT-assessed myosteatosis) and visceral adipose tissue area (CT-assessed visceral obesity). This study explored the impact of contrast phase timing on changes in morphometric measurements of body composition.

METHODS

This single-center retrospective cohort study included 459 patients undergoing a multiphase CT scan. Morphometric measurements were obtained at the third lumbar vertebra level. Patients were classified as sarcopenic, myosteatotic, or visceral obese using predefined cutoff values. The intraclass correlation coefficient was used to assess correlations across different enhancement phases, and Cohen's κ measured the inter-enhancement agreement for sarcopenia, myosteatosis, and visceral obesity.

RESULTS

Significant differences were observed in mean visceral adipose tissue area, muscle density, and muscle area (P < 0.001). The intraclass correlation coefficient between unenhanced and arterial phases was 0.987 (95% confidence interval [CI], 0.759-0.996) for adipose tissue, 0.995 (95% CI, 0.989-0.997) for muscle area, and 0.850 (95% CI, 0.000-0.956) for muscle density. However, when morphometric measurements were categorized using predefined cutoffs, the κ agreement was considerably lower, particularly for CT-assessed myosteatosis, ranging from 0.635 (unenhanced to arterial) to 0.331 (unenhanced to late venous phase).

CONCLUSIONS

Different CT contrast phases induce small but clinically significant alterations in the measurements of muscle area and density and visceral fat. Such minor changes can result in misclassification issues when fixed cutoff values are used to diagnose myosteatosis with CT. This underscores the importance of reporting absolute values and the specific contrast phase used in future studies.

The relation between preoperative radiological sarcopenia and postoperative recovery of physical activity in older surgical cancer patients; an explorative study

To identify older surgical cancer patients at risk of decreased postoperative recovery of physical activity (PA), this study assesses whether preoperative radiological sarcopenia (RS) is associated with a decreased ability to return to baseline PA. RS was defined as decreased psoas muscle mass or -density by gender-specific cut-offs on CT-scans at level of vertebra L3. PA was assessed as steps/day measured with PA tracker and recovery of PA was defined as >90% of preoperative steps/day at 3 months postoperatively. Of 44 included patients aged 65 and over undergoing oncologic surgery, 18 patients (41%) showed RS. Seventeen patients (39%) returned to baseline PA, of which eight patients had RS (47%). RS was not associated with a return to baseline PA (OR: 1.38, 95%CI 0.39-4.92, p = 0.61). In this exploratory study, no association was found between preoperative RS and recovery of PA postoperatively.

Pretreatment Computed Tomography-Defined Sarcopenia, Treatment-Associated Muscle Loss, and Survival in Patients With Cervical Cancer: A Systematic Review and Meta-Analysis

CONTEXT

Sarcopenia has been identified as a potential predictor of poor prognosis in various types of cancer. However, the impact of pretreatment sarcopenia and the reduction of skeletal muscle mass during treatment on survival outcomes of patients with cervical cancer is still not well understood.

OBJECTIVE

This meta-analysis was conducted to investigate the impact of pretreatment sarcopenia and treatment-associated muscle loss on survival outcomes in patients with cervical cancer.

DATA SOURCES

The PubMed, EMBASE, Web of Science, and Cochrane Library databases were searched for studies exploring the relationship between muscle loss and the prognosis of cervical cancer until January 1, 2023.

DATA EXTRACTION

The hazard ratios (HRs) and 95% CIs for overall survival (OS) and progression-free survival (PFS) were extracted.

DATA ANALYSIS

The data were analyzed using R software. The studies' quality was assessed using the Quality in Prognostic Studies tool. Twelve observational studies involving 1498 patients with cervical cancer were included in the analysis, with a prevalence of sarcopenia ranging from 24.8% to 57.5%. Sarcopenia was an independent predictor of poor OS (HR, 1.68; 95% CI, 1.28-2.21; P < .01) and PFS (HR, 1.53; 95% CI, 1.19-1.98; P < .01) in patients with cervical cancer. Additionally, the decrease in skeletal muscle during treatment was also significantly related to the OS (HR, 4.46; 95% CI, 2.87-6.94; P < .01) and PFS (HR, 2.89; 95% CI. 1.83-4.55; P < .01).

CONCLUSIONS

The prevalence of pretreatment sarcopenia was high among patients with cervical cancer. Pretreatment sarcopenia and skeletal muscle loss during treatment both negatively affected prognosis in cervical cancer.

Body Composition in Primary Hyperparathyroidism: A Potential Contributor to Weakness and Fatigue

BACKGROUND

Primary hyperparathyroidism (PHPT) patients commonly report weakness and fatigue, though the underlying mechanisms are uncertain. Our purpose is to determine whether CT-derived muscle and adipose tissue metrics are associated with weakness and fatigue in PHPT patients.

METHODS

For this retrospective study, cross-sectional muscle and adipose tissue metrics were derived from CTs in PHPT patients undergoing preoperative imaging within 1 year of parathyroid surgery. Skeletal muscle index (SMI) and visceral adipose tissue (VAT)/subcutaneous adipose tissue (SAT) ratio were calculated based on a single CT image at the level of the L3 vertebra. Established sex-specific SMI thresholds were used to define sarcopenia. Demographic and clinical data were collected from the electronic health record. When available, postoperative CT images were analyzed to assess for changes in body composition pre- and post-parathyroidectomy.

RESULTS

The cohort comprised 53 PHPT patients (38 females, 15 males, mean age 61.4 years), of whom 24 (45%) reported weakness, 43 (81%) reported fatigue, and 31 (58%) met CT-based criteria for sarcopenia. Lower SMI was significantly associated with preoperative weakness in females but not males. For both weakness and fatigue, VAT/SAT ratios were higher in symptomatic females and lower in symptomatic males than their asymptomatic counterparts, though these differences were not statistically significant. In patients with postoperative CTs (n = 23), no significant changes in CT metrics were observed after parathyroidectomy.

DISCUSSION

In females but not males with PHPT, subjective preoperative weakness was significantly associated with lower SMI. Effects of parathyroid hormone on skeletal muscle and visceral adiposity may differ by sex.

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.

Research Progress on Patients of Esophageal Cancer Complicated with Sarcopenia

Aims/Background The application of immunochemotherapy has significantly enhanced the quality of life and overall survival of patients with esophageal cancer. Sarcopenia, which is increasingly prevalent in these patients, markedly affects prognosis, but can be reversed by appropriate and effective treatment. Methods The narrative review was conducted on PubMed using the keywords ("esophageal" or "esophagus" and "sarcopenia"). Results This article reviews the measurement, timing, and intervention strategies for sarcopenia in patients with esophageal cancer. It summarizes the evaluation indicators of skeletal muscle loss in these patients, analyzes the barriers to intervention for frailty among esophageal cancer patients, and proposes corresponding countermeasures. Conclusion Patients with esophageal cancer often suffer from severe sarcopenia. Clinical intervention is crucial in addressing this issue.

Association between atherogenic dyslipidemia and muscle quality defined by myosteatosis

Background

Myosteatosis, ectopic fat accumulation in skeletal muscle, is a crucial component of sarcopenia, linked to various cardiometabolic diseases. This study aimed to analyze the association between dyslipidemia and myosteatosis using abdominal computed tomography (CT) in a large population.

Methods

This study included 11,823 patients not taking lipid-lowering medications with abdominal CT taken between 2012 and 2013. Total abdominal muscle area (TAMA), measured at the L3 level, was segmented into skeletal muscle area (SMA) and intramuscular adipose tissue. SMA was further classified into normal attenuation muscle area (NAMA: good quality muscle) and low attenuation muscle area (poor quality muscle). NAMA divided by TAMA (NAMA/TAMA) represents good quality muscle. Atherosclerotic dyslipidemia was defined as high-density lipoprotein cholesterol (HDL-C) less than 40 mg/dL in men and 50 mg/dL in women, low-density lipoprotein cholesterol (LDL-C) greater than 160 mg/dL, triglycerides (TG) greater than 150 mg/dL, small dense LDL-C (sdLDL-C) greater than 50.0 mg/dL, or apolipoprotein B/A1 (apoB/A1) greater than 0.08.

Results

The adjusted odds ratios (ORs) of dyslipidemia according to the HDL-C and sdLDL definitions were greater in both sexes in the lower quartiles (Q1~3) of NAMA/TAMA compared with Q4. As per other definitions, the ORs were significantly increased in only women for LDL-C and only men for TG and ApoB/A1. In men, all lipid parameters were significantly associated with NAMA/TAMA, while TG and ApoB/A1 did not show significant association in women.

Conclusion

Myosteatosis measured in abdominal CT was significantly associated with a higher risk of dyslipidemia. Myosteatosis may be an important risk factor for dyslipidemia and ensuing cardiometabolic diseases.

Sarcopenia predicts postoperative complications in head and neck cancer: a systematic review and meta-analysis

PURPOSE

We performed this systematic review and meta-analysis to explore the impact of preoperative sarcopenia on postoperative complication risks after head and neck cancer (HNC) surgery.

METHODS

We identified eligible studies by searching Ovid-MEDLINE, Ovid-Embase, EBM Reviews-Cochrane Central Register of Controlled Trials, Web of Science Core Collection, and Scopus. This systematic review was performed in accordance with the Preferred Reporting Items for Systematic Reviews and Meta-Analyses guidance.

RESULTS

Twenty-one studies with a total of 3480 patients met our inclusion criteria. The presence of sarcopenia significantly increased the incidence of overall postoperative complications (OR = 1.72, 95% CI 1.23, 2.41; P = 0.002; I2 = 59%). Subgroup analyses showed a higher risk of postoperative complications in the populations in which sarcopenia was diagnosed with low L3-skeletal muscle index (L3-SMI) or low cross-sectional area of the rectus femoris, but not in the group that sarcopenia was diagnosed with low C3-SMI. Preoperative sarcopenia also substantially increased the risk of severe postoperative complications (OR = 2.26), pharyngocutaneous fistulas (OR = 2.15), free flap-related complications (OR = 1.63), and surgical site infections (OR = 1.84). We also found a tendency toward a higher incidence of wound complications and 30-day mortality in patients with sarcopenia.

CONCLUSION

Preoperative sarcopenia is a negative prognostic indicator for postoperative complications in patients with HNC after surgery. To reduce the incidence of postoperative complications and improve poor prognosis, further attention needs to be paid to the evaluation and management of preoperative sarcopenia.

Age-adjusted Charlson comorbidity index and its association with body composition and overall survival in patients with colorectal cancer

OBJECTIVE

To examine the relationship between the age-adjusted Charlson comorbidity index (A-CCI) with body composition and overall survival in patients newly diagnosed with colorectal cancer (CRC).

RESEARCH METHODS AND PROCEDURES

In this cohort study, patients (≥ 18 years old) with CRC were followed for 36 months. Computed tomography images of the third lumbar were analyzed to determine body composition, including skeletal muscle area (SMA), skeletal muscle index (SMI), skeletal muscle radiodensity (SMD), visceral adipose tissue (VAT), and subcutaneous adipose tissue (SAT). Phenotypes based on comorbidity burden assessed by A-CCI and body composition parameters were established.

RESULTS

A total of 436 participants were included, 50% male, with a mean age of 61 ± 13.2 years. Approximately half of the patients (50.4%) had no comorbidity, and the A-CCI median score was 4 (interquartile range: 3-6). A higher A-CCI score was a risk factor for 36-month mortality (HR = 3.59, 95% CI = 2.17-5.95). Low SMA and low SMD were associated with a higher A-CCI. All abnormal phenotypes (high A-CCI and low SMA; high A-CCI and low SMD; high A-CCI and high VAT) were independently associated with higher 36-month mortality hazard (adjusted HR 5.12, 95% CI 2.73-9.57; adjusted HR 4.58, 95% CI 2.37-8.85; and adjusted HR 2.36, 95% CI 1.07-5.22, respectively).

CONCLUSION

The coexistence of comorbidity burden and abnormal body composition phenotypes, such as alterations in muscle or fat compartments, may pose an additional risk of mortality in patients newly diagnosed with CRC. Early assessment and management of these phenotypes could be crucial in optimizing outcomes in such patients.

Assessment of Psoas Muscle Index in Middle-Aged Type 2 Diabetes Patients: Impact of Insulin Therapy on Sarcopenia

OBJECTIVE

Sarcopenia, characterized by progressive skeletal muscle loss, poses significant health risks, including physical impairment and mortality. The relationship between sarcopenia and insulin resistance suggests insulin therapy's potential in preserving muscle mass, particularly in Type 2 diabetes mellitus (T2DM) patients. This study aims to evaluate the Psoas Muscle Index (PMI) via computed tomography (CT) in middle-aged T2DM patients on insulin therapy versus oral antidiabetic drugs (OAD) and controls.

METHODS

This retrospective study included 107 middle-aged T2DM patients undergoing non-contrast CT scans and 58 age-matched controls. CT images were analyzed to calculate PMI. Statistical analysis included Chi-square tests, independent samples t-tests, Mann-Whitney U tests, and correlation analyses.

RESULTS

Insulin-treated patients exhibited higher PMI than OAD users (p < 0.001), while OAD users had lower PMI than controls (p < 0.001). No significant difference was found between insulin-treated patients and controls (p = 0.616). Negative correlations were observed between T2DM duration/age and PMI across all groups, with a positive correlation between T2DM duration and BMI observed in the OAD group.

CONCLUSIONS

Insulin therapy in T2DM patients, regardless of age or disease duration, positively impacts muscle mass, highlighting its potential in preserving muscular health and advocating for tailored treatment strategies in T2DM management.

Association of mid-thigh quadriceps muscle quality with postoperative outcomes in patients with hip osteoarthritis undergoing total hip arthroplasty: a retrospective cohort study

PURPOSE

Muscle quality is more important than muscle mass for assessing physical function. Computed tomography (CT) is used to evaluate intramuscular fatty infiltration. The mid-thigh quadriceps CT attenuation values (CTV) expressed in Hounsfield units (HU) negatively correlate with physical function. Patients with hip osteoarthritis (HOA) have lower extremity muscle atrophy, including decreased cross-sectional area (CSA), CTV, and muscle strength. Using preoperative CT images, we investigated the association between mid-thigh quadriceps CSA, CTV, and postoperative outcomes in patients with HOA.

METHODS

This study included 62 patients who had unilateral HOA (62 hips) and underwent total hip arthroplasty (THA). We investigated the association between preoperative and postoperative Japanese Orthopaedic Association (JOA) hip scores, 12-item Short Form survey (SF-12), mid-thigh quadriceps CSA, and CTV.

RESULTS

The mean age was 64.7 ± 10.1 years, with 15 men (24.2%), and the mean body mass index was 24.3 ± 4.3 kg/m2. Secondary HOA was present in 79.0% of patients. The mean CSA and CTV of the mid-thigh quadriceps on the operative side were 38.8 ± 9.8 cm2 and 40.3 ± 7.8 HU, respectively. Multiple regression analyses adjusted for age and sex showed that preoperative mid-thigh quadriceps CSA was not associated with preoperative and postoperative JOA hip scores or SF-12. The preoperative mid-thigh quadriceps CTV was associated with the postoperative JOA hip score in the gait ability domain and SF-12 in the physical component summary domain.

CONCLUSION

Preoperative muscle quality is associated with postoperative outcomes in patients who have HOA regardless of age and sex.

Tumor metabolic activity is associated with subcutaneous adipose tissue radiodensity and survival in non-small cell lung cancer

BACKGROUND

Cachexia-associated body composition alterations and tumor metabolic activity are both associated with survival of cancer patients. Recently, subcutaneous adipose tissue properties have emerged as particularly prognostic body composition features. We hypothesized that tumors with higher metabolic activity instigate cachexia related peripheral metabolic alterations, and investigated whether tumor metabolic activity is associated with body composition and survival in patients with non-small-cell lung cancer (NSCLC), focusing on subcutaneous adipose tissue.

METHODS

A retrospective analysis was performed on a cohort of 173 patients with NSCLC. 18F-fluorodeoxyglucose positron emission tomography-computed tomography (PET-CT) scans obtained before treatment were used to analyze tumor metabolic activity (standardized uptake value (SUV) and SUV normalized by lean body mass (SUL)) as well as body composition variables (subcutaneous and visceral adipose tissue radiodensity (SAT/VAT radiodensity) and area; skeletal muscle radiodensity (SM radiodensity) and area). Subjects were divided into groups with high or low SAT radiodensity based on Youden Index of Receiver Operator Characteristics (ROC). Associations between tumor metabolic activity, body composition variables, and survival were analyzed by Mann-Whitney tests, Cox regression, and Kaplan-Meier analysis.

RESULTS

The overall prevalence of high SAT radiodensity was 50.9% (88/173). Patients with high SAT radiodensity had shorter survival compared with patients with low SAT radiodensity (mean: 45.3 vs. 50.5 months, p = 0.026). High SAT radiodensity was independently associated with shorter overall survival (multivariate Cox regression HR = 1.061, 95% CI: 1.022-1.101, p = 0.002). SAT radiodensity also correlated with tumor metabolic activity (SULpeak rs = 0.421, p = 0.029; SUVpeak rs = 0.370, p = 0.048). In contrast, the cross-sectional areas of SM, SAT, and VAT were not associated with tumor metabolic activity or survival.

CONCLUSION

Higher SAT radiodensity is associated with higher tumor metabolic activity and shorter survival in patients with NSCLC. This may suggest that tumors with higher metabolic activity induce subcutaneous adipose tissue alterations such as decreased lipid density, increased fibrosis, or browning.

Fatty infiltration of gastrocnemius-soleus muscle complex: Considerations for myosteatosis rehabilitation

Although previous studies have reported fatty infiltration of the gastrocnemius-soleus complex, little is known about the volumetric distribution and patterns of fatty infiltration. The purpose of this anatomical study was to document and quantify the frequency, distribution, and pattern of fatty infiltration of the gastrocnemius-soleus complex. One hundred formalin-embalmed specimens (mean age 78.1 ± 12.3 years; 48F/52M) were serially dissected to document the frequency, distribution, and pattern of fatty infiltration in the medial and lateral heads of gastrocnemius and soleus muscles. Fatty infiltration was found in 23% of specimens, 13 unilaterally (8F/5M) and 10 (5M/5F) bilaterally. The fatty infiltration process was observed to begin medially from the medial aspect of the medial head of gastrocnemius and medial margin of soleus and then progressed laterally throughout the medial head of gastrocnemius and the marginal, anterior, and posterior soleus. The lateral head of gastrocnemius remained primarily muscular in all specimens. Microscopically, the pattern of infiltration was demonstrated as intramuscular with intact aponeuroses, and septa. The remaining endo-, peri-, and epimysium preserved the overall contour of the gastrocnemius-soleus complex, even in cases of significant fatty replacement. Since the external contour of the calf is preserved, the presence of fatty infiltration may be underdiagnosed in the clinic without imaging. Myosteatosis is associated with gait and balance challenges in the elderly, which can impact quality of life and result in increased risk of falling. The findings of the study have implications in the rehabilitation management of elderly patients with sarcopenia and myosteatosis.

CT imaging-derived phenotypes for abdominal muscle and their association with age and sex in a medical biobank

The study of muscle mass as an imaging-derived phenotype (IDP) may yield new insights into determining the normal and pathologic variations in muscle mass in the population. This can be done by determining 3D abdominal muscle mass from 12 distinct abdominal muscle regions and groups using computed tomography (CT) in a racially diverse medical biobank. To develop a fully automatic technique for assessment of CT abdominal muscle IDPs and preliminarily determine abdominal muscle IDP variations with age and sex in a clinically and racially diverse medical biobank. This retrospective study was conducted using the Penn Medicine BioBank (PMBB), a research protocol that recruits adult participants during outpatient visits at hospitals in the Penn Medicine network. We developed a deep residual U-Net (ResUNet) to segment 12 abdominal muscle groups including the left and right psoas, quadratus lumborum, erector spinae, gluteus medius, rectus abdominis, and lateral abdominals. 110 CT studies were randomly selected for training, validation, and testing. 44 of the 110 CT studies were selected to enrich the dataset with representative cases of intra-abdominal and abdominal wall pathology. The studies were divided into non-overlapping training, validation and testing sets. Model performance was evaluated using the Sørensen-Dice coefficient. Volumes of individual muscle groups were plotted to distribution curves. To investigate associations between muscle IDPs, age, and sex, deep learning model segmentations were performed on a larger abdominal CT dataset from PMBB consisting of 295 studies. Multivariable models were used to determine relationships between muscle mass, age and sex. The model's performance (Dice scores) on the test data was the following: psoas: 0.85 ± 0.12, quadratus lumborum: 0.72 ± 0.14, erector spinae: 0.92 ± 0.07, gluteus medius: 0.90 ± 0.08, rectus abdominis: 0.85 ± 0.08, lateral abdominals: 0.85 ± 0.09. The average Dice score across all muscle groups was 0.86 ± 0.11. Average total muscle mass for females was 2041 ± 560.7 g with a high of 2256 ± 560.1 g (41-50 year old cohort) and a change of - 0.96 g/year, declining to an average mass of 1579 ± 408.8 g (81-100 year old cohort). Average total muscle mass for males was 3086 ± 769.1 g with a high of 3385 ± 819.3 g (51-60 year old cohort) and a change of - 1.73 g/year, declining to an average mass of 2629 ± 536.7 g (81-100 year old cohort). Quadratus lumborum was most highly correlated with age for both sexes (correlation coefficient of - 0.5). Gluteus medius mass in females was positively correlated with age with a coefficient of 0.22. These preliminary findings show that our CNN can automate detailed abdominal muscle volume measurement. Unlike prior efforts, this technique provides 3D muscle segmentations of individual muscles. This technique will dramatically impact sarcopenia diagnosis and research, elucidating its clinical and public health implications. Our results suggest a peak age range for muscle mass and an expected rate of decline, both of which vary between genders. Future goals are to investigate genetic variants for sarcopenia and malnutrition, while describing genotype-phenotype associations of muscle mass in healthy humans using imaging-derived phenotypes. It is feasible to obtain 3D abdominal muscle IDPs with high accuracy from patients in a medical biobank using fully automated machine learning methods. Abdominal muscle IDPs showed significant variations in lean mass by age and sex. In the future, this tool can be leveraged to perform a genome-wide association study across the medical biobank and determine genetic variants associated with early or accelerated muscle wasting.

Morphofunctional Assessment beyond Malnutrition: Fat Mass Assessment in Adult Patients with Phenylketonuria-Systematic Review

Morphofunctional assessment was developed to evaluate disease-related malnutrition. However, it can also be used to assess cardiometabolic risk, as excess adiposity increases this risk. Phenylketonuria (PKU) is the most prevalent inherited metabolic disease among adults, and obesity in PKU has recently gained interest, although fat mass correlates better with cardiometabolic risk than body mass index. In this systematic review, the objective was to assess whether adult patients with PKU have higher fat mass than healthy controls. Studies of adult PKU patients undergoing dietary treatment in a metabolic clinic reporting fat mass were included. The PubMed and EMBASE databases were searched. Relevance of articles, data collection, and risk of bias were evaluated by two independent reviewers. Ten articles were evaluated, six with a control group, including 310 subjects with PKU, 62 with mild hyperphenylalaninemia, and 157 controls. One study reported a significant and four a tendency towards an increased fat mass in all patients or only females with PKU. Limitations included not having a healthy control group, not reporting sex-specific results and using different techniques to assess fat mass. Evaluation of fat mass should be included in the morphofunctional assessment of cardiometabolic risk in adult patients with PKU.

New Perspectives for Estimating Body Composition From Computed Tomography: Clothing Associated Artifacts

As the value of clinical imaging is expanded through retrospective analyses, it is imperative that all efforts are made to optimize validity. Such considerations for retrospective designs should prioritize factors like naturalistic conditions for observations and measurement replicability, while avoiding sample biases and reliance on strict clinical timelines. Valid methodological approaches are immanent for successful translation from retrospective observational designs into prospective pragmatic research with actionable potential. In particular, thousands of studies have sought to associate clinical outcomes to measures of body composition across diverse patient groups. Post-hoc use of computed tomography (CT) to quantify adiposity and lean tissue characteristics has most frequently involved just a single slice at the level of the third lumbar vertebrae (L3). Abundant in statistical significance and inconsistencies alike, such methods have yet to be implemented or deemed valuable for making real-world clinical decisions. We present herein a concerning perspective, for both magnitude and prevalence, of a widely overlooked source of data variability for this methodology: the hinderance of pants and other tightly fit clothing.

Sarcopenia with decreased total psoas muscle area in children with high-risk neuroblastoma

BACKGROUND

We calculated psoas muscle area (PMA) z-scores in high-risk neuroblastoma patients undergoing treatment to examine the clinical significance of sarcopenia in this cohort.

METHODS

We analyzed retrospective data from patients aged 0-18 who were diagnosed with abdominal neuroblastoma between 2005 and 2019 at Samsung Medical Center. Patients categorized as high-risk undergone induction chemotherapy, neuroblastoma excision, and tandem high-dose chemotherapy with autologous stem cell transplantation (HDCT/auto-SCT) were selected. L3-4 lumbar levels on axial CT images were identified and we measured the areas of the left and right psoas muscles to determine tPMA. Total PMA z-scores were calculated using an open online tool.

RESULTS

There were 45 boys and 25 girls with a mean age of 3.86 years. CT images taken at initial diagnosis and after tandem HDCT/auto-SCT were selected to calculate tPMA z-scores. Mean elapsed time between the two measurements was 12.91 ± 1.73 months. Mean tPMA z-score significantly decreased from -0.21 ± 1.29 to -0.66 ± 0.97 (p = 0.022). Length of hospital stay was significantly longer in the group of patients whose tPMA z-scores decreased by more than .45 (177.62 ± 28.82 days vs. 165.75 ± 21.34 days, p = 0.049). Presence of sarcopenia at initial diagnosis was a significant risk factor for bacterial infection during neuroblastoma treatment.

CONCLUSION

tPMA z-scores in high-risk neuroblastoma patients decreased significantly following a treatment regimen that included induction chemotherapy, tumor resection surgery, and HDCT/auto-SCT. A greater decrease in tPMA z-score was associated with longer hospital stay during treatment.

The association between sarcopenia and adverse outcomes after complex endovascular aortic repair

BACKGROUND

Sarcopenia is identified as a predictive factor for adverse outcomes after complex endovascular aortic repair (complex EVAR). Consensus on preferred parameters for sarcopenia is not yet reached. The current study compares three CT-assessed parameters on their association with adverse outcomes after complex EVAR.

METHODS

This was a single-center retrospective cohort study. Psoas Muscle Index (PMI), Skeletal Muscle Index (SMI), and lean psoas muscle area (LPMA) were examined by CT-segmentation. PMI, SMI, and LPMA were analyzed as continuous variables. In addition, cut-off values from previous research were used to diagnose patients as sarcopenic or non-sarcopenic. Outcomes were: all-cause mortality, major adverse events (MAE), length of hospital stay, and non-home discharge. A sub-analysis was made for severe sarcopenia; sarcopenia combined with low physical performance (gait speed, Time Up and Go test, Metabolic Equivalent of Task-score).

RESULTS

We included 101 patients. A higher PMI (HR=0.590, CI: 0.374-0.930, P=0.023), SMI (HR=0.453, CI: 0.267-0.768, P=0.003), and LPMA (HR=0.559, CI: 0.333-0.944, P=0.029) were associated with a lower risk of mortality. Sarcopenia based on cut-off values for PMI and LPMA was not significantly associated with survival. Sarcopenia based on SMI did present a higher mortality risk (P=0.017). A sub-analysis showed that severely sarcopenic patients were at even higher risk of mortality (P=0.036). None of the parameters were significantly associated with the other outcomes.

CONCLUSIONS

SMI had a slightly stronger association with mortality compared to PMI and LPMA. High-risk patients were selected by adding physical performance scores. Future research could focus on complex EVAR-specific PMI and LPMA cut-off values.

Prognostic utility of paraspinal muscle index in elderly patients with community-acquired pneumonia

OBJECTIVE

This study investigated the associations between paraspinal muscle measurements on chest computed tomography and clinical outcomes of elderly patients with community-acquired pneumonia (CAP).

METHODS

This single-center, retrospective, observational study analyzed elderly patients (≥65 years) with CAP hospitalized through an emergency department between March 2020 and December 2022. We collected their baseline characteristics and laboratory data at the time of admission. The paraspinal muscle index and attenuation were calculated at the level of the 12th thoracic vertebra using chest computed tomography taken within 48 hours before or after admission. Univariable and multivariable logistic regression analyses were conducted to evaluate the association between paraspinal muscle measurements and 28-day mortality. Receiver operating characteristic (ROC) curve and area under the curve (AUC) analyses were used to evaluate the prognostic predictive power.

RESULTS

Of the 338 enrolled patients, 60 (17.8%) died within 28 days after admission. A high paraspinal muscle index was associated with low 28-day mortality in elderly patients with CAP (adjusted odds ratio, 0.994; 95% confidence interval, 0.992-0.997). The area under the ROC curve for the muscle index was 0.75, which outperformed the pneumonia severity index and the CURB-65 (confusion, urea, respiratory rate, blood pressure, age ≥65 years) metric, both of which showed an AUC of 0.64 in predicting mortality.

CONCLUSION

A high paraspinal muscle index was associated with low 28-day mortality in patients aged 65 years or older with CAP.

Assessment of myosteatosis and functionality in pretreatment gynecological cancer patients

PURPOSE

We aimed to investigate the relationship between pretreatment gynecologic cancer survival and the physical function of patients with myosteatosis. Understanding this relationship prior to treatment would help healthcare providers identify and refer patients with poor muscle quality to an exercise program prior to treatment.

METHODS

We conducted a cross-sectional analysis of 73 GC patients. Physical function was quantified using handgrip strength and an adapted version of the Senior Fitness Test (aerobic endurance not included). The EORTC QLC-C30 was used to evaluate general health quality. Myosteatosis (values below the median muscle radiodensity), muscle mass, and adipose tissue variables were calculated from the computed tomography (CT) scan at the third lumbar vertebra using specific software.

RESULTS

Seventy patients (50.9 ± 15.2) were included; 41.5% had stage III or IV disease, and 61.4% had cervical cancer. The myosteatosis group was 11.9 years older and showed reduced functioning compared to the normal-radiodensity group. Age and Timed Up and Go (TUG) test results were shown to be the most reliable predictors of muscle radiodensity in pretreatment gynecological patients according to multivariate regression analysis (R2 = 0.314).

CONCLUSION

Gynecological healthcare professionals should be aware that prompt exercise programs might be especially beneficial for older patients with reduced TUG performance to preserve muscle function and quality.

Prevalence and clinical implications of sarcopenia in breast cancer: a systematic review and meta-analysis

PURPOSE

The impact of sarcopenia in oncology is increasingly recognized, yet little is known about its clinical implications in breast cancer. This systematic review and meta-analysis estimates the overall prevalence of sarcopenia in breast cancer, quantifies skeletal muscle index (SMI), and comprehensively evaluates sarcopenia's impact on clinical outcomes.

METHODS

We systematically searched primary original research published before June 2023 in four databases: the Cochrane Library via Wiley, CINAHL Plus with Full Text, Embase via Elsevier Excerpta Medica, and Medline via Ovid. Standardized mean SMI and 95% confidence interval (CI) were calculated by applying the random-effects model. The methodological quality of the included studies was assessed using the National Institutes of Health quality assessment checklist.

RESULTS

The systematic review included 17 studies with a total of 9863 patients; the meta-analysis included 12 of these studies. The mean prevalence of sarcopenia in breast cancer (stages I-III) was 32.5%. The mean SMI assessed by CT was 43.94 cm2/m2 (95% CI 42.87, 45.01; p < .01). Overall, low muscle mass was associated with chemotherapy toxicities, dose reductions, dose delays, or treatment discontinuation. Low muscle mass was generally associated with poor survival, but in some studies, this association was not significant or reversed direction.

CONCLUSION

Sarcopenia is not just a state of muscle mass loss, but an influencing factor on therapeutic effects and survival rates in oncology. It is thus necessary to recognize the risk of sarcopenia throughout the trajectory of cancer treatment, identify low muscle mass early, and manage it from a prehabilitation perspective.

Association of physical activity with fatty infiltration of muscles after total hip arthroplasty

OBJECTIVE

This study aimed to investigate the association between muscle density as an indicator of fatty infiltration of lower extremity muscles and physical activity (PA) after total hip arthroplasty (THA) and identify the patient characteristics with high postoperative PA.

METHODS

This study included 62 female patients who underwent THA for unilateral hip osteoarthritis. Muscle density of the gluteus maximus, gluteus medius, iliopsoas, and quadriceps muscles was measured using computed tomography (CT). PA was assessed using University of California, Los Angeles (UCLA) activity scores. CT and UCLA activity score were obtained before and 1 year after THA. The patients were divided into two groups, sufficient (score ≥ 6) and insufficient (score < 6) activity groups, based on their level of PA as determined by their UCLA activity score 1 year after THA. The association of PA with the amount of changes in muscle density was examined with Spearman's rank correlation coefficient. Logistic regression analysis was performed to identify postoperative factors determining PA at 1 year after THA.

RESULTS

Spearman's rank correlation coefficient showed a significantly positive association between recovery in PA and an increase in muscle density of the gluteus maximus, gluteus medius, iliopsoas, and quadriceps muscles. Additionally, logistic regression analysis confirmed that postoperative muscle densities of the gluteus maximus and quadriceps muscles were variables determining the PA 1 year after THA.

CONCLUSION

The findings of this study indicated that the improvement of fatty infiltration in lower limb muscles, especially in the gluteus maximus and quadriceps, is likely to promote the increase in postoperative PA.

Glucocorticoid-Induced Myopathy: Typology, Pathogenesis, Diagnosis, and Treatment

Glucocorticoid-induced myopathy is a non-inflammatory toxic myopathy typified by proximal muscle weakness, muscle atrophy, fatigue, and easy fatigability. These vague symptoms coupled with underlying disorders may mask the signs of glucocorticoid-induced myopathy, leading to an underestimation of the disease's impact. This review briefly summarizes the classification, pathogenesis, and treatment options for glucocorticoid-induced muscle wasting. Additionally, we discuss current diagnostic measures in clinical research and routine care used for diagnosing and monitoring glucocorticoid-induced myopathy, which includes gait speed tests, muscle strength tests, hematologic tests, bioelectrical impedance analysis (BIA), dual-energy X-ray absorptiometry (DXA), computed tomography (CT), magnetic resonance imaging (MRI), electromyography, quantitative muscle ultrasound, histological examination, and genetic analysis. Continuous monitoring of patients receiving glucocorticoid therapy plays an important role in enabling early detection of glucocorticoid-induced myopathy, allowing physicians to modify treatment plans before significant clinical weakness arises.

Myosteatosis is associated with poor survival after kidney transplantation: a large retrospective cohort validation

PURPOSE

We aim to establish diagnostic thresholds of sarcopenia and myosteatosis based on CT measurements, and to validate their prognostic value in a large cohort of kidney transplant recipients.

METHODS

Local healthy population with abdominal CT between 2010 and 2022, and patients underwent kidney transplantation between 2015 and 2019 at our center were retrospectively included. The skeletal muscle index and muscle attenuation of abdominal muscles were calculated based on CT image at the middle of the third lumbar vertebra. Primary endpoints included all-cause mortality and death censored allograft survival.

RESULTS

Age- and sex-specific thresholds for sarcopenia and myosteatosis were established based on 1598 healthy local population. The final patient cohort consisted of 992 kidney transplant recipients (median age 34 years, interquartile range 28-44 years; 694 males), including 33 (3.3%) with sarcopenia and 95 (9.5%) with myosteatosis. Multivariate analysis revealed myosteatosis (adjusted hazard ratio = 3.08, p = 0.022) was an independent baseline risk factor of mortality after adjusting for age, the history of cancer, and the history of cardiovascular event. Multivariate analysis found preemptive transplantation (adjusted hazard ratio = 0.36, p = 0.037) was an independent protective factor of allograft loss. No difference was found in the prognosis between kidney transplant recipients with and without sarcopenia.

CONCLUSION

Myosteatosis was an independent risk factor of mortality after kidney transplantation, but sarcopenia was not. Neither sarcopenia nor myosteatosis was associated with graft loss.

Myosteatosis is associated with coronary artery calcification in patients with type 2 diabetes

BACKGROUND

Myosteatosis, rather than low muscle mass, is the primary etiologic factor of sarcopenia in patients with type 2 diabetes mellitus (T2DM). Myosteatosis may lead to a series of metabolic dysfunctions, such as insulin resistance, systematic inflammation, and oxidative stress, and all these dysfunctions are closely associated with the acceleration of T2DM and atherosclerosis.

AIM

To investigate the association between myosteatosis and coronary artery calcification (CAC) in patients with T2DM.

METHODS

Patients with T2DM, who had not experienced major cardiovascular events and had undergone both abdominal and thoracic computed tomography (CT) scans, were included. The mean skeletal muscle attenuation was assessed using abdominal CT images at the L3 level. The CAC score was determined from thoracic CT images using the Agatston scoring method. Myosteatosis was diagnosed according to Martin's criteria. Severe CAC (SCAC) was defined when the CAC score exceeded 300. Logistic regression and decision tree analyses were performed.

RESULTS

A total of 652 patients with T2DM were enrolled. Among them, 167 (25.6%) patients had SCAC. Logistic regression analysis demonstrated that myosteatosis, age, duration of diabetes, cigarette smoking, and alcohol consumption were independent risk factors of SCAC. Myosteatosis was significantly associated with an increased risk of SCAC (OR = 2.381, P = 0.003). The association between myosteatosis and SCAC was significant in the younger patients (OR = 2.672, 95%CI: 1.477-4.834, P = 0.002), but not the older patients (OR = 1.456, 95%CI: 0.863-2.455, P = 0.188), and was more prominent in the population with lower risks of atherosclerosis. The decision tree analyses prioritized older age as the primary variable for SCAC. In older patients, cigarette smoking was the main contributing factor for SCAC, while in younger patients, it was myosteatosis.

CONCLUSION

Myosteatosis is a novel risk factor for atherosclerosis in patients with T2DM, especially in the population with younger ages and fewer traditional risk factors.

Clinical, functional, and opportunistic CT metrics of sarcopenia at the point of imaging care: analysis of all-cause mortality

PURPOSE

This study examines clinical, functional, and CT metrics of sarcopenia and all-cause mortality in older adults undergoing outpatient imaging.

METHODS

The study included outpatients ≥ 65 years of age undergoing CT or PET/CT at a tertiary care institution. Assessments included screening questionnaires for sarcopenia (SARC-F) and frailty (FRAIL scale), and measurements of grip strength and usual gait speed (6 m course). Skeletal muscle area (SMA), index (SMI, area/height2) and density (SMD) were measured on CT at T12 and L3. A modified SMI was also examined (SMI-m, area/height). Mortality risk was studied with Cox proportional hazard analysis.

RESULTS

The study included 416 patients; mean age 73.8 years [sd 6.2]; mean follow-up 2.9 years (sd 1.34). Abnormal grip, SARC-F, and FRAIL scale assessments were associated with higher mortality risk (HR [95%CI] = 2.0 [1.4-2.9], 1.6 [1.1-2.3], 2.0 [1.4-2.8]). Adjusting for age, higher L3-SMA, T12-SMA, T12-SMI and T12-SMI-m were associated with lower mortality risk (HR [95%CI] = 0.80 [0.65-0.90], 0.76 [0.64-0.90], 0.84 [0.70-1.00], and 0.80 [0.67-0.90], respectively). T12-SMD and L3-SMD were not predictive of mortality. After adjusting for abnormal grip strength and FRAIL scale assessments, T12-SMA and T12-SMI-m remained predictive of mortality risk (HR [95%CI] = 0.83 [0.70-1.00] and 0.80 [0.67-0.97], respectively).

CONCLUSION

CT areal metrics were weaker predictors of all-cause mortality than clinical and functional metrics of sarcopenia in our older patient cohort; a CT density metric (SMD) was not predictive. Of areal CT metrics, SMI (area/height2) appeared to be less effective than non-normalized SMA or SMA normalized by height1.

Hepatocellular carcinoma in patients with non-alcoholic fatty liver disease is associated with heterogeneous pattern of fat infiltration in skeletal muscles

OBJECTIVES

To evaluate the association between fat infiltration in skeletal muscles (myosteatosis) and hepatocellular carcinoma (HCC) in patients with non-alcoholic fatty liver disease (NAFLD).

METHODS

In a cross-sectional cohort of 72 histologically proven NAFLD patients (n = 38 with non-alcoholic steatohepatitis; NASH), among which 20 had HCC diagnosed on biopsy, we used proton density fat fraction (PDFF) at MRI to evaluate myosteatosis in skeletal muscles (mean fat fraction and first order radiomic-based pattern) at the third lumbar level, namely in erector spinae (ES), quadratus lumborum (QL), psoas, oblique, and rectus muscles.

RESULTS

PDFFES was 70% higher in patients with HCC when compared to those without HCC (9.6 ± 5.5% versus 5.7 ± 3.0%, respectively, p < 0.001). In multivariate logistic regression, PDFFES was a significant predictor of the presence of HCC (AUC = 0.72, 95% CI 0.57-0.86, p = 0.002) independently from age, sex, visceral fat area, and liver fibrosis stage (all p < 0.05). The relationship between PDFFES and HCC was exacerbated in patients with NASH (AUC = 0.79, 95% CI 0.63-0.86, p = 0.006). In patients with NASH, radiomics features of heterogeneity such as energy and entropy in any of the paraspinal muscles (i.e., ES, QL, or psoas) were independent predictors of HCC. EnergyES identified patients with HCC (n = 13) in the NASH population with AUC = 0.92 (95% CI 0.82-1.00, p < 0.001).

CONCLUSION

In patients with NAFLD, and more specifically in those with NASH, the degree and heterogeneity of myosteatosis is independently associated with HCC irrespective of liver fibrosis stage.

CLINICAL RELEVANCE STATEMENT

Our data suggest that myosteatosis could be used as a biomarker of HCC in the ever-expanding NAFLD population and pave the way for further investigation in longitudinal studies.

KEY POINTS

• HCC in patients with non-alcoholic fatty liver disease, and more specifically in those with non-alcoholic steatohepatitis, is independently associated with severe fatty infiltration (myosteatosis) of paravertebral skeletal muscles. • Association between myosteatosis and HCC is independent from liver fibrosis stage. • Histogram-based radiomics features of myosteatosis predicts the risk of HCC in patients with non-alcoholic steatohepatitis.

Making the invisible visible: imaging techniques for assessing muscle mass and muscle quality in chronic kidney disease

Muscle wasting and low muscle mass are prominent features of protein energy wasting (PEW), sarcopenia and sarcopenic obesity in patients with chronic kidney disease (CKD). In addition, muscle wasting is associated with low muscle strength, impaired muscle function and adverse clinical outcomes such as low quality of life, hospitalizations and increased mortality. While assessment of muscle mass is well justified, the assessment of skeletal muscle should go beyond quantity. Imaging techniques provide the means for non-invasive, comprehensive, in-depth assessment of the quality of the muscle such as the infiltration of ectopic fat. These techniques include computed tomography (CT), magnetic resonance imaging (MRI) and ultrasound. Dual energy X-ray absorptiometry is also an imaging technique, but one that only provides quantitative and not qualitative data on muscle. The main advantage of imaging techniques compared with other methods such as bioelectrical impedance analysis and anthropometry is that they offer higher precision and accuracy. On the other hand, the higher cost for acquiring and maintaining the imaging equipment, especially CT and MRI, makes these less-used options and available mostly for research purposes. In the field of CKD and end-stage kidney disease (ESKD), imaging techniques are gaining attention for evaluating muscle quantity and more recently muscle fat infiltration. This review describes the potential of these techniques in CKD and ESKD settings for muscle assessment beyond that of muscle quantity.

Fatigue, sarcopenia, and frailty in older adults with inflammatory bowel disease

Inflammatory bowel diseases (IBDs) are characterized by a multifactorial clinical picture, in which age-related physical, functional and psychological symptoms may coexist. The accurate evaluation and identification of such symptomatology acquires considerable importance in the context of older adults, since those core factors typical of IBD may also expose older patients to an increased risk for age-related negative outcomes, such as frailty and disability. The purpose of the present review was to provide an updated overview on the evaluation and management of IBD in the elderly population, with regard to fatigue, sarcopenia, and frailty. The assessment of fatigue might contribute to the identification of early symptoms of IBD, such as pain and mood disorders, which should be treated timely to offer elderly patient a better quality of life. Similarly, an accurate evaluation of sarcopenia might represent a useful Prognostic Index to identify those patients at risk of developing physical frailty. Frailty in IBD should be evaluated not only in relation to the occurrence of negative outcomes, but also should be considered itself as an outcome itself in IBD. A recommendation for future research on this topic might be the implementation of randomized trials, which include older adults and evaluate fatigue, sarcopenia, and frailty. Similarly, the development of tailored intervention programs, based on both physical and psychological outcomes, with the purpose of improving patients' adaptation to the disease, and monitoring the evolution of symptoms and the response to therapies over time, should be encouraged.

Sarcopenic Obesity in Cervical Carcinoma: A Strong and Independent Prognostic Factor beyond the Conventional Predictors (ESTHER Study-AFRAID Project)

Locally advanced cervical cancer represents a significant treatment challenge. Body composition parameters such as body mass index, sarcopenia, and sarcopenic obesity, defined by sarcopenia and BMI ≥ 30 kg/m2, have been identified as potential prognostic factors, yet their overall impact remains underexplored. This study assessed the relationship between these anthropometric parameters alongside clinical prognostic factors on the prognosis of 173 cervical cancer patients. Survival outcomes in terms of local control (LC), distant metastasis-free survival (DMFS), disease-free survival (DFS), and overall survival (OS) were analyzed using Kaplan regression methods-Meier and Cox. Older age, lower hemoglobin levels, higher FIGO (International Federation of Gynecology and Obstetrics) stages, and lower total radiation doses were significantly associated with worse outcomes. Univariate analysis showed a significant correlation between BMI and the outcomes examined, revealing that normal-weight patients show higher survival rates, which was not confirmed by the multivariate analysis. Sarcopenia was not correlated with any of the outcomes considered, while sarcopenic obesity was identified as an independent negative predictor of DFS (HR: 5.289, 95% CI: 1.298-21.546, p = 0.020) and OS (HR: 2.645, 95% CI: 1.275-5.488, p = 0.009). This study highlights the potential of sarcopenic obesity as an independent predictor of clinical outcomes. These results support their inclusion in prognostic assessments and treatment planning for patients with advanced cervical cancer.

Biomarkers of Body Composition

The importance and impact of imaging biomarkers has been increasing over the past few decades. We review the relevant clinical and imaging terminology needed to understand the clinical and research applications of body composition. Imaging biomarkers of bone, muscle, and fat tissues obtained with dual-energy X-ray absorptiometry, computed tomography, magnetic resonance imaging, and ultrasonography are described.

Computed tomography-based abdominal sarcopenic indices and bio-impedance analysis-based skeletal muscle mass index in hemodialyzed patients

BACKGROUND AND AIMS

Information about muscle wasting in hemodialyzed patients evaluated using computed tomography (CT) is limited. The present study aimed to examine the relationships between CT-based abdominal sarcopenic indices and bio-impedance analysis (BIA)-based skeletal muscle mass index (SMMI) in these patients.

METHODS

A total of 100 consecutive maintenance hemodialyzed patients who underwent CT and BIA were included. The psoas muscle index (PMI), paraspinous muscle index (PSMI), and abdominal skeletal muscle index (ASMI) were calculated by adjusting each muscle area to the height square. The psoas muscle thickness per height (PMTH) was measured using a single cross-sectional CT image obtained at the level of the third lumbar vertebra. The relationships between these CT-based sarcopenic indices and the BIA-based SMMI were examined. Moreover, the diagnostic values of these CT-based indices for BIA-defined muscle wasting (defined by the sex-specific SMMI: males, <7.0 kg/m2; females, <5.7 kg/m2) were investigated.

RESULTS

The PMI, PMTH, PSMI, and ASMI were significantly correlated with the SMMI (r = 0.678, 0.760, 0.708, and 0.785, respectively; p < 0.0001 for all). Twenty-eight patients with reduced muscle mass determined by BIA were identified. After age-sex adjustment, a multivariate logistic regression analysis revealed that the C-statistics of the PMI, PMTH, PSMI, and ASMI for the diagnosis of low muscle mass were 0.863 (p = 0.0099), 0.870 (p = 0.013), 0.891 (p = 0.040), and 0.950 (reference), respectively.

CONCLUSIONS

CT-based abdominal sarcopenic indices presented here may be useful for evaluating muscle wasting in hemodialyzed patients; the ASMI may be the most recommended sarcopenic index for such evaluations.

Imaging of Sarcopenia in Type 2 Diabetes Mellitus

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

Automatic deep learning method for third lumbar selection and body composition evaluation on CT scans of cancer patients

Introduction

The importance of body composition and sarcopenia is well-recognized in cancer patient outcomes and treatment tolerance, yet routine evaluations are rare due to their time-intensive nature. While CT scans provide accurate measurements, they depend on manual processes. We developed and validated a deep learning algorithm to automatically select and segment abdominal muscles [SM], visceral fat [VAT], and subcutaneous fat [SAT] on CT scans.

Materials and Methods

A total of 352 CT scans were collected from two cancer centers. The detection of the third lumbar vertebra and three different body tissues (SM, VAT, and SAT) were annotated manually. The 5-fold cross-validation method was used to develop the algorithm and validate its performance on the training cohort. The results were validated on an external, independent group of CT scans.

Results

The algorithm for automatic L3 slice selection had a mean absolute error of 4 mm for the internal validation dataset and 5.5 mm for the external validation dataset. The median DICE similarity coefficient for body composition was 0.94 for SM, 0.93 for VAT, and 0.86 for SAT in the internal validation dataset, whereas it was 0.93 for SM, 0.93 for VAT, and 0.85 for SAT in the external validation dataset. There were high correlation scores with sarcopenia metrics in both internal and external validation datasets.

Conclusions

Our deep learning algorithm facilitates routine research use and could be integrated into electronic patient records, enhancing care through better monitoring and the incorporation of targeted supportive measures like exercise and nutrition.

Muscle-related parameters-based machine learning model for predicting postinduction hypotension in patients undergoing colorectal tumor resection surgery

Objectives

This study used machine learning algorithms to identify important variables and predict postinduction hypotension (PIH) in patients undergoing colorectal tumor resection surgery.

Methods

Data from 318 patients who underwent colorectal tumor resection under general anesthesia were analyzed. The training and test sets are divided based on the timeline. The Boruta algorithm was used to screen relevant basic characteristic variables and establish a model for the training set. Four models, regression tree, K-nearest neighbor, neural network, and random forest (RF), were built using repeated cross-validation and hyperparameter optimization. The best model was selected, and a sorting chart of the feature variables, a univariate partial dependency profile, and a breakdown profile were drawn. R2, mean absolute error (MAE), mean squared error (MSE), and root MSE (RMSE) were used to plot regression fitting curves for the training and test sets.

Results

The basic feature variables associated with the Boruta screening were age, sex, body mass index, L3 skeletal muscle index, and HUAC. In the optimal RF model, R2 was 0.7708 and 0.7591, MAE was 0.0483 and 0.0408, MSE was 0.0038 and 0.0028, and RMSE was 0.0623 and 0.0534 for the training and test sets, respectively.

Conclusion

A high-performance algorithm was established and validated to demonstrate the degree of change in blood pressure after induction to control important characteristic variables and reduce PIH occurrence.

Computed tomography evaluation of skeletal muscle quality and quantity in people with morbid obesity with and without metabolic abnormality

We investigated the differences in quantity and quality of skeletal muscle between metabolically healthy obese (MHO) and metabolically unhealthy obese (MUO) individuals using abdominal CT. One hundred and seventy-two people with morbid obesity who underwent bariatric surgery and 64 healthy control individuals participated in this retrospective study. We divided the people with morbid obesity into an MHO and MUO group. In addition, nonobese metabolic healthy people were included analysis to provide reference levels. CT evaluation of muscle quantity (at the level of the third lumbar vertebra [L3]) was performed by calculating muscle anatomical cross-sectional area (CSA), which was normalized to patient height to produce skeletal muscle index (SMI). Muscle quality was assessed as skeletal muscle density (SMD), which was calculated from CT muscle attenuation. To characterize intramuscular composition, muscle attenuation was classified into three categories using Hounsfield unit (HU) thresholds: -190 HU to -30 HU for intermuscular adipose tissue (IMAT), -29 to +29 HU for low attenuation muscle (LAM), and +30 to +150 HU for normal attenuation muscle (NAM). People with morbid obesity comprised 24 (14%) MHO individuals and 148 (86%) MUO individuals. The mean age of the participants was 39.7 ± 12.5 years, and 154 (65%) participants were women. MUO individuals had a significantly greater total skeletal muscle CSA than MHO individuals in the model that adjusted for all variables. Total skeletal muscle SMI, SMD, NAM index, LAM index, and IMAT index did not differ between MHO and MUO individuals for all adjusted models. Total skeletal muscle at the L3 level was not different in muscle quantity, quality, or intramuscular composition between the MHO and MUO individuals, based on CT evaluation. MHO individuals who are considered "healthy" should be carefully monitored and can have a similar risk of metabolic complications as MUO individuals, at least based on an assessment of skeletal muscle.

Body Composition Evaluation and Clinical Markers of Cardiometabolic Risk in Patients with Phenylketonuria

Cardiovascular diseases are the main cause of mortality worldwide. Patients with phenylketonuria (PKU) may be at increased cardiovascular risk. This review provides an overview of clinical and metabolic cardiovascular risk factors, explores the connections between body composition (including fat mass and ectopic fat) and cardiovascular risk, and examines various methods for evaluating body composition. It particularly focuses on nutritional ultrasound, given its emerging availability and practical utility in clinical settings. Possible causes of increased cardiometabolic risk in PKU are also explored, including an increased intake of carbohydrates, chronic exposure to amino acids, and characteristics of microbiota. It is important to evaluate cardiovascular risk factors and body composition in patients with PKU. We suggest systematic monitoring of body composition to develop nutritional management and hydration strategies to optimize performance within the limits of nutritional therapy.

Different computed tomography parameters for defining myosteatosis in patients with advanced non-small cell lung cancer

BACKGROUND & AIMS

Myosteatosis, excess muscle fat infiltration, is a novel prognostic factor in cancer patients. To define myosteatosis, skeletal muscle radiodensity (SMD) is most commonly used, while intramuscular adipose tissue (IMAT) is newly introduced. We aimed to compare SMD-defined and IMAT-defined myosteatosis for predicting overall survival (OS) in patients with advanced non-small cell lung cancer (NSCLC) and to explore whether patients with both low SMD and high IMAT had a shorter OS than patients with low SMD or high IMAT alone.

METHODS

We consecutively and prospectively recruited adult patients with stage IIIB or IV NSCLC at a teaching hospital. The mean SMD of all skeletal muscle areas and the area of IMAT on the unenhanced chest computed tomography (CT) images at the 12th thoracic vertebral level were segmented using Mimics version 21.0. Myosteatosis was defined by either low SMD (SMD-defined myosteatosis) or high IMAT (IMAT-defined myosteatosis). The optimal cutoffs for low SMD and high IMAT were also determined using the maximally selected rank statistics method. We calculated hazard ratios (HRs) and the corresponding confidence intervals (CIs) to evaluate the associations of OS with low SMD, high IMAT, and a combination of them.

RESULTS

We included 565 patients (345 men and 220 women; mean age 58.5 ± 9.0 years). Lower IMAT exhibited a tendency toward a favorable prognosis in men (p = 0.0015) and women (p < 0.0001); whereas higher SMD tended to have a favorable prognosis in men (p = 0.0006) and women (p < 0.0001). At baseline, 423 (74.9 %) participants had high IMAT, 432 (76.5 %) participants had low SMD and 370 (65.5 %) participants had both high IMAT and low SMD. Compared to those without either high IMAT or low SMD, the participants with either high IMAT or low SMD had a shorter OS, while the participants with both High IMAT and Low SMD had the shortest OS (log-rank p < 0.0001). After adjustment for the same confounders, high IMAT (HR, 1.44; 95 % CI, 1.10-1.87) and low SMD (HR, 1.92; 95 % CI, 1.36-2.43) were separately associated with poor prognosis. Moreover, the combination of high IMAT and low SMD indicated a higher risk of poor prognosis (HR, 2.43; 95 % CI, 1.62-3.66).

CONCLUSIONS

Both SMD-defined and IMAT-defined myosteatosis are highly prevalent in patients with advanced NSCLC and may serve as independent prognostic factors for OS. The diagnosis of myosteatosis might consider a combination of low SMD and high IMAT because this would help identify patients at a higher risk of mortality.

Impact of sarcopenia on outcomes in surgical patients: a systematic review and meta-analysis

BACKGROUND

Surgeons have historically used age as a preoperative predictor of postoperative outcomes. Sarcopenia, the loss of skeletal muscle mass due to disease or biological age, has been proposed as a more accurate risk predictor. The prognostic value of sarcopenia assessment in surgical patients remains poorly understood. Therefore, the authors aimed to synthesize the available literature and investigate the impact of sarcopenia on perioperative and postoperative outcomes across all surgical specialties.

METHODS

The authors systematically assessed the prognostic value of sarcopenia on postoperative outcomes by conducting a systematic review and meta-analysis according to Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) guidelines, searching the PubMed/MEDLINE and EMBASE databases from inception to 1st October 2022. Their primary outcomes were complication occurrence, mortality, length of operation and hospital stay, discharge to home, and postdischarge survival rate at 1, 3, and 5 years. Subgroup analysis was performed by stratifying complications according to the Clavien-Dindo classification system. Sensitivity analysis was performed by focusing on studies with an oncological, cardiovascular, emergency, or transplant surgery population and on those of higher quality or prospective study design.

RESULTS

A total of 294 studies comprising 97 643 patients, of which 33 070 had sarcopenia, were included in our analysis. Sarcopenia was associated with significantly poorer postoperative outcomes, including greater mortality, complication occurrence, length of hospital stay, and lower rates of discharge to home (all P <0.00001). A significantly lower survival rate in patients with sarcopenia was noted at 1, 3, and 5 years (all P <0.00001) after surgery. Subgroup analysis confirmed higher rates of complications and mortality in oncological (both P <0.00001), cardiovascular (both P <0.00001), and emergency ( P =0.03 and P =0.04, respectively) patients with sarcopenia. In the transplant surgery cohort, mortality was significantly higher in patients with sarcopenia ( P <0.00001). Among all patients undergoing surgery for inflammatory bowel disease, the frequency of complications was significantly increased among sarcopenic patients ( P =0.007). Sensitivity analysis based on higher quality studies and prospective studies showed that sarcopenia remained a significant predictor of mortality and complication occurrence (all P <0.00001).

CONCLUSION

Sarcopenia is a significant predictor of poorer outcomes in surgical patients. Preoperative assessment of sarcopenia can help surgeons identify patients at risk, critically balance eligibility, and refine perioperative management. Large-scale studies are required to further validate the importance of sarcopenia as a prognostic indicator of perioperative risk, especially in surgical subspecialties.

Reduced CT-derived erector spinae muscle area: a poor prognostic factor for short- and long-term outcomes in idiopathic pulmonary fibrosis patients

AIM

To assess the relationship between idiopathic pulmonary fibrosis (IPF) prognosis, baseline skeletal muscle mass, and attenuation on computed tomography (CT) and clinical parameters.

MATERIAL AND METHODS

This retrospective cohort study enrolled 195 patients. The mean follow-up duration was 42.52 months. Erector spinae muscle area (ESMA), pectoralis muscle area (PMA), and the attenuation of the erector spinae muscle at the level of T12 vertebrae were measured. Muscle indexes were obtained by adjusting the measured muscle areas to the patients' heights. The relationship between baseline CT-derived muscle metrics and clinical parameters including short- and long-term mortality were evaluated.

RESULTS

There was a moderate correlation between ESMA and PMA and pectoralis muscle index (PMI; r=0.536, p<0001 and r=0.403, p<0.001 respectively). ESMA correlated significantly with forced expiratory volume in 1 second (FEV1; hazard ratio [HR] = 0.488 p<0.001) and forced vital capacity (FVC; HR=0.501, p<0.001). Compared with PMA, ESMA was more strongly associated with 1- and 2-year mortality in patients with IPF (HR=0.957, p=0.022). The survival rate in male patients with sarcopenia was significantly worse (p=0.040).

CONCLUSION

ESMA measurements obtained from CT correlated with clinical parameters in IPF patients and were also predictors of short- and long-term survival.

Computed tomography-determined skeletal muscle density predicts 3-year mortality in initial-dialysis patients in China

BACKGROUND

Skeletal muscle mass and quality assessed by computed tomography (CT) images of the third lumbar vertebra (L3) level have been established as risk factors for poor clinical outcomes in several illnesses, but the relevance for dialysis patients is unclear. A few studies have suggested a correlation between CT-determined skeletal muscle mass and quality at the first lumbar vertebra (L1) level and adverse outcomes. Generally, chest CT does not reach beyond L1. We aimed to determine whether opportunistic CT scan (chest CT)-determined skeletal muscle mass and quality at L1 are associated with mortality in initial-dialysis patients.

METHODS

This 3-year multicentric retrospective study included initial-dialysis patients from four centres between 2014 and 2017 in China. Unenhanced CT images of the L1 and L3 levels were obtained to assess skeletal muscle mass [by skeletal muscle index, (SMI), cm2 /m2 ] and quality [by skeletal muscle density (SMD), HU]. Skeletal muscle measures at L1 were compared with those at L3. The sex-specific optimal cutoff values of L1 SMI and L1 SMD were determined in relation to all-cause mortality. The outcomes were all-cause death and cardiac death. Cox regression models were applied to investigate the risk factors for death.

RESULTS

A total of 485 patients were enrolled, of whom 257 had both L1 and L3 images. Pearson's correlation coefficient between L1 and L3 SMI was 0.84 (P < 0.001), and that between L1 and L3 SMD was 0.90 (P < 0.001). No significant association between L1 SMI and mortality was observed (P > 0.05). Low L1 SMD (n = 280, 57.73%) was diagnosed based on the optimal cutoff value (<39.56 HU for males and <33.06 HU for females). Multivariate regression analysis revealed that the low L1 SMD group had higher risks of all-cause death (hazard ratio 1.80; 95% confidence interval 1.05-3.11, P = 0.034) and cardiac death (hazard ratio 3.74; 95% confidence interval 1.43-9.79, P = 0.007).

CONCLUSIONS

In initial-dialysis patients, there is high agreement between the L1 and L3 measures for SMI and SMD. Low SMD measured at L1, but not low SMI, is an independent predictor of both all-cause death and cardiac death.

Opportunistic assessment of ischemic heart disease risk using abdominopelvic computed tomography and medical record data: a multimodal explainable artificial intelligence approach

Current risk scores using clinical risk factors for predicting ischemic heart disease (IHD) events-the leading cause of global mortality-have known limitations and may be improved by imaging biomarkers. While body composition (BC) imaging biomarkers derived from abdominopelvic computed tomography (CT) correlate with IHD risk, they are impractical to measure manually. Here, in a retrospective cohort of 8139 contrast-enhanced abdominopelvic CT examinations undergoing up to 5 years of follow-up, we developed multimodal opportunistic risk assessment models for IHD by automatically extracting BC features from abdominal CT images and integrating these with features from each patient's electronic medical record (EMR). Our predictive methods match and, in some cases, outperform clinical risk scores currently used in IHD risk assessment. We provide clinical interpretability of our model using a new method of determining tissue-level contributions from CT along with weightings of EMR features contributing to IHD risk. We conclude that such a multimodal approach, which automatically integrates BC biomarkers and EMR data, can enhance IHD risk assessment and aid primary prevention efforts for IHD. To further promote research, we release the Opportunistic L3 Ischemic heart disease (OL3I) dataset, the first public multimodal dataset for opportunistic CT prediction of IHD.

A simplified D3 -creatine dilution method for skeletal muscle mass determination with dynamic correction of creatinine and D3 -creatinine using ultra-performance liquid chromatography-tandem mass spectrometry

This study developed a simple method for muscle mass determination based on D3 -creatine dilution by removing the matrix effects of ultra-performance liquid chromatography-tandem mass spectrometry analysis through mutual correction of creatinine and D3 -creatinine. Rats were administered an oral tracer dose of D3 -creatine at age 6 weeks. Creatinine and D3 -creatinine in urine were detected using ultra-performance liquid chromatography-tandem mass spectrometry after diluting 20 times to obtain D3 -creatinine enrichment factor (mole percent excess). The mole percent excess obtained from peak area could be used to calculate muscle mass using the improved formula. The limit of detection was 0.500 ng/mL for D3 -creatinine. Creatinine and D3 -creatinine could be mutually corrected because of the same matrix effect, and D3 -creatine spillage was negligible within 0.22%. Isotopic steady time was consistent with that obtained using conventional methods. Bland-Altman plots demonstrated the satisfying consistency between the proposed method and magnetic resonance imaging. This is a simple and rapid measuring method of muscle mass based on D3 -creatine dilution that requires no accurate quantification of creatinine and D3 -creatinine concentrations and no urine sample collection to obtain D3 -creatine spillage.

Sarcopenia and myosteatosis diagnostic tool for gastrointestinal cancer: creatinine to cystatin C ratio as evaluation marker

OBJECTIVE

This study aimed to develop a simplified diagnostic tool for assessing sarcopenia and myosteatosis in gastrointestinal cancer patients, focusing on the creatinine to cystatin C ratio (CCR) as an evaluation marker.

METHODS

955 patients were split into training (n = 671) and validation (n = 284) cohorts. Using logistic regression, risk factors for sarcopenia and myosteatosis were identified. The predictive capacity of the developed model was examined. The association between CCR and muscle imaging parameters, along with its impact on clinical outcomes, was analyzed.

RESULTS

No significant differences were observed in baseline traits between cohorts. CCR emerged as a significant risk factor for both sarcopenia and myosteatosis. Nomograms for diagnosing these conditions demonstrated strong predictive ability, with AUC values indicating high accuracy (sarcopenia AUC: 0.865-0.872; myosteatosis AUC: 0.848-0.849). The clinical utility of the nomograms was confirmed through decision curve analysis. CCR showed significant association with muscle imaging parameters and was a reliable indicator for assessing the risk of sarcopenia, myosteatosis, and cachexia. Moreover, CCR was able to differentiate between patient survival and disease progression rates.

CONCLUSION

A diagnostic tool for sarcopenia and myosteatosis in gastrointestinal cancer patients was developed, with CCR being a pivotal biomarker for disease diagnosis and prognosis prediction.