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

Body composition predicts mortality and decompensation in compensated cirrhosis patients: A prospective cohort study

Background & Aims

Body composition, particularly sarcopenia, is associated with mortality in patients with decompensated cirrhosis undergoing transplant evaluation. Similar data are limited for non-transplant eligible or compensated patients.

Methods

A total of 274 patients with cirrhosis were followed prospectively for ≤5 years after a CT scan. We utilized Analytic Morphomics® to measure body composition (fat, muscle, and bone) which was rendered into relative values (percentiles) in relation to a reference population. The model for end-stage liver disease (MELD) score was used as a reference model for survival prediction. We validated our models in a separate cohort.

Results

Our cohort had a mean Child-Pugh score of 7.0 and a mean MELD of 11.3. The median follow-up time was 5.05 years. The proportion of patients alive at 1, 3 and 5 years was 86.5%, 68.0%, and 54.3%; 13 (4.6%) underwent liver transplantation. Child-Pugh B/C (vs. A) cirrhosis was associated with decreased muscle, subcutaneous, and visceral fat area but increased subcutaneous/visceral fat density. Decreased normal density muscle mass was associated with mortality (hazard ratio [HR] 0.984, p <0.001) as well as visceral and subcutaneous fat density (HR 1.013 and 1.014, respectively, p <0.001). Models utilizing these features outperformed MELD alone for mortality discrimination in both the derivation and validation cohort, particularly for those with compensated cirrhosis (C-statistics of 0.74 vs. 0.58). Using competing risk analysis, we found that subcutaneous fat density was most predictive of decompensation (subdistribution HR 1.018, p = 0.0001).

Conclusion

The addition of body composition features to predictive models improves the prospective determination of prognosis in patients with cirrhosis, particularly those with compensated disease. Fat density, a novel feature, is associated with the risk of decompensation.

Lay summary

Am I at high risk of getting sicker and dying? This is the key question on the mind of patients with cirrhosis. The problem is that we have very few tools to help guide our patients, particularly if they have early cirrhosis (without symptoms like confusion or fluid in the belly). We found that how much muscle and fat the patient has and what that muscle or fat looks like on a CT scan provide helpful information. This is important because many patients have CT scans and this information is hiding in plain sight.

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Features of body composition can predict clinical outcomes in patients with cirrhosis awaiting liver transplantation.

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Data are lacking regarding long-term outcomes among patients with compensated disease.

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We show that features of muscle and fat are associated with decompensation and risk of death across the spectrum of cirrhosis.

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CT scans obtained for unrelated clinical purposes can be analyzed as a digital risk biomarker for patients with compensated cirrhosis.

Bedside Measures of Frailty and Cognitive Function Correlate with Sarcopenia in Patients with Cirrhosis

BACKGROUND

Frailty and sarcopenia are associated with mortality and poor outcomes among patients with cirrhosis. Frailty is multifactorial but due in part to sarcopenia and cognitive dysfunction. Data are limited regarding the correlation of bedside frailty and cognitive function measures with sarcopenia.

AIMS

To evaluate the correlations between frailty measures and muscle indices from computed tomography (CT).

METHODS

We prospectively enrolled 106 patients with clinically compensated cirrhosis (and no prior hepatic encephalopathy). All patients underwent CT scan and cognitive testing (via inhibitory control test, ICT), and were subject to hand grip, 30-s chair stands, mid-arm muscle area (MAMA), and a four-question algorithm based on the Sickness Impact Profile (SIP) predictive of minimal HE. We evaluated Spearman correlations between all measures as well as the sensitivity and specificity of each measure for falls.

RESULTS

In total, 106 (35.3%) patients (55 men) had CT scans to measure skeletal muscle area and quality. Hand grip correlated strongly with skeletal muscle area (correlation coefficient 0.64, p < 0.001) and mildly with ICT performance (0.34, p = 0.002). However, for women, the strongest correlation with hand grip was ICT performance (0.60, p < 0.001). Chair stand performance correlated best with SIP (correlation coefficient - 0.35, p < 0.001). MAMA was not correlated with CT-based muscle indices among women but was for men. Poor chair stand performance (< 10/30-s) had a sensitivity/specificity for falls of 73%/54%; low muscle radiation attenuation (density) was 40%/80% sensitive/specific.

CONCLUSION

Bedside measures of physical function, muscle bulk, and cognitive performance are correlated with CT-based muscle measures. Bedside measures of frailty may provide an advantage over sarcopenia for outcome assessment that should be confirmed prospectively.

Clinical and biological characterization of skeletal muscle tissue biopsies of surgical cancer patients

BACKGROUND

Researchers increasingly use intraoperative muscle biopsy to investigate mechanisms of skeletal muscle atrophy in patients with cancer. Muscles have been assessed for morphological, cellular, and biochemical features. The aim of this study was to conduct a state-of-the-science review of this literature and, secondly, to evaluate clinical and biological variation in biopsies of rectus abdominis (RA) muscle from a cohort of patients with malignancies.

METHODS

Literature was searched for reports on muscle biopsies from patients with a cancer diagnosis. Quality of reports and risk of bias were assessed. Data abstracted included patient characteristics and diagnoses, sample size, tissue collection and biobanking procedures, and results. A cohort of cancer patients (n = 190, 88% gastrointestinal malignancies), who underwent open abdominal surgery as part of their clinical care, consented to RA biopsy from the site of incision. Computed tomography (CT) scans were used to quantify total abdominal muscle and RA cross-sectional areas and radiodensity. Biopsies were assessed for muscle fibre area (μm² ), fibre types, myosin heavy chain isoforms, and expression of genes selected for their involvement in catabolic pathways of muscle.

RESULTS

Muscle biopsy occurred in 59 studies (total N = 1585 participants). RA was biopsied intraoperatively in 40 studies (67%), followed by quadriceps (26%; percutaneous biopsy) and other muscles (7%). Cancer site and stage, % of male participants, and age were highly variable between studies. Details regarding patient medical history and biopsy procedures were frequently absent. Lack of description of the population(s) sampled and low sample size contributed to low quality and risk of bias. Weight-losing cases were compared with weight stable cancer or healthy controls without considering a measure of muscle mass in 21 out of 44 studies. In the cohort of patients providing biopsy for this study, 78% of patients had preoperative CT scans and a high proportion (64%) met published criteria for sarcopenia. Fibre type distribution in RA was type I (46% ± 13), hybrid type I/IIA (1% ± 1), type IIA (36% ± 10), hybrid type IIA/D (15% ± 14), and type IID (2% ± 5). Sexual dimorphism was prominent in RA CT cross-sectional area, mean fibre cross-sectional area, and in expression of genes associated with muscle growth, apoptosis, and inflammation (P < 0.05). Medical history revealed multiple co-morbid conditions and medications.

CONCLUSIONS

Continued collaboration between researchers and cancer surgeons enables a more complete understanding of mechanisms of cancer-associated muscle atrophy. Standardization of biobanking practices, tissue manipulation, patient characterization, and classification will enhance the consistency, reliability, and comparability of future studies.

Single-slice CT measurements allow for accurate assessment of sarcopenia and body composition

OBJECTIVES

To evaluate the correlation between simple planimetric measurements in axial computed tomography (CT) slices and measurements of patient body composition and anthropometric data performed with bioelectrical impedance analysis (BIA) and metric clinical assessments.

METHODS

In this prospective cross-sectional study, we analyzed data of a cohort of 62 consecutive, untreated adult patients with advanced malignant melanoma who underwent concurrent BIA assessments at their radiologic baseline staging by CT between July 2016 and October 2017. To assess muscle and adipose tissue mass, we analyzed the areas of the paraspinal muscles as well as the cross-sectional total patient area in a single CT slice at the height of the third lumbar vertebra. These measurements were subsequently correlated with anthropometric (body weight) and body composition parameters derived from BIA (muscle mass, fat mass, fat-free mass, and visceral fat mass). Linear regression models were built to allow for estimation of each parameter based on CT measurements.

RESULTS

Linear regression models allowed for accurate prediction of patient body weight (adjusted R² = 0.886), absolute muscle mass (adjusted R² = 0.866), fat-free mass (adjusted R² = 0.855), and total as well as visceral fat mass (adjusted R² = 0.887 and 0.839, respectively).

CONCLUSIONS

Our data suggest that patient body composition can accurately and quantitatively be determined by using simple measurements in a single axial CT slice. This could be useful in various medical and scientific settings, where the knowledge of the patient's anthropometric parameters is not immediately or easily available.

KEY POINTS

• Easy to perform measurements on a single CT slice highly correlate with clinically valuable parameters of body composition. • Body composition data were acquired using bioelectrical impedance analysis to correlate CT measurements with a non-imaging-based method, which is frequently lacking in previous studies. • The obtained equations facilitate a quick, opportunistic assessment of relevant parameters of body composition.

A Clinical Feasible Method for Computed Tomography-Based Assessment of Sarcopenia in Patients With Chronic Pancreatitis

OBJECTIVES

Sarcopenia is a serious but often overlooked complication of chronic pancreatitis (CP). We investigated the prevalence and risk factors for sarcopenia in patients with CP and determined the utility of a computed tomography (CT)-based method, based on psoas muscle measurements, for easy and clinical feasible diagnosis of sarcopenia.

METHODS

This was a retrospective multicenter study of 265 patients with CP. We used segmentation of CT images to quantify skeletal muscle mass and diagnose sarcopenia. On the same CT image as used for muscle segmentation, psoas muscle thickness and cross-sectional area were measured and receiver operating characteristic analyses defined age and sex-specific cutoffs for diagnosing sarcopenia.

RESULTS

The prevalence of sarcopenia was 20.4%. The optimal height-adjusted psoas muscle cross-sectional area cutoff for diagnosing sarcopenia was 3.3 cm/m in males and 2.5 cm/m in females. The corresponding area under the receiver operating characteristic curves were 0.8 and 0.9, with sensitivities of 84% and 81% and specificities of 62% and 81%, respectively. Comparable diagnostic performance characteristics were observed for psoas muscle thickness.

CONCLUSIONS

Sarcopenia is present in 1 of 5 patients with CP. Assessment of psoas muscle parameters provides a clinical feasible method to diagnose sarcopenia.

A nonlinear relationship between visceral adipose tissue and frailty in adult lung transplant candidates

Frailty is a state of decreased physiologic reserve associated with poor outcomes before and after lung transplantation. Obesity, particularly central obesity characterized by excess proinflammatory visceral adipose tissue (VAT), is associated with incident frailty in middle-aged and older adults. The association between VAT and frailty in advanced lung disease, however, is unknown. In two, nonoverlapping multicenter cohorts of adults listed for lung transplantation, we measured VAT area on bioelectrical impedance assay (BIA) in one cohort and cross-sectional VAT and subcutaneous adipose tissue (SAT) areas on abdominal computed tomography (CT) in the other. We identified a nonlinear relationship between greater VAT by BIA and frailty. In fully adjusted piecewise regression models, every 20 cm² increase in VAT area was associated with 50% increased odds of frailty in subjects with high VAT (95% CI 1.2-1.9, P < .001), and 10% decreased odds of frailty (95% CI 0.7-1.04, P = .12) in subjects with low VAT. Compared to frail subjects with low VAT, those with high VAT were more likely to have low grip strength and less likely to have weight loss, suggesting that mechanisms of frailty may differ by VAT. Further investigation of mechanisms linking VAT and frailty may identify new targets for prevention and treatment.

CT- and MRI-Based Assessment of Body Composition and Pancreatic Fibrosis Reveals High Incidence of Clinically Significant Metabolic Changes That Affect the Quality of Life and Treatment Outcomes of Patients with Chronic Pancreatitis and Pancreatic Cancer

Background and Objectives: Both chronic pancreatitis (CP) and pancreatic ductal adenocarcinoma (PDAC) may lead to cachexia, sarcopenia, and osteoporosis due to different mechanisms. Neither patient gender, age, nor body weight are good predictors of these metabolic changes having a significant negative impact on the quality of life (QOL) and treatment outcomes. The aim of this study was to evaluate radiological changes in body composition and to compare them with manifestations of exocrine and endocrine pancreatic insufficiency, body mass, and QOL among patients with CP and PDAC. Materials and Methods: Prospectively collected data of 100 patients with diagnosed CP or PDAC were used for analysis. All patients underwent dual-energy X-ray absorptiometry (DXA), computed tomography (CT), and magnetic resonance imaging (MRI). The European Organization for Research and Treatment of Cancer Quality of Life Questionnaire-C30 (EORTC QLQ-C30) was used to assess QOL. Diabetes and changes in fecal elastase-1 were also assessed. Results: There was no significant difference in skeletal muscle mass (SMM) among patients with CP and PDAC (p = 0.85). Significantly more underweight patients had low SMM (p = 0.002). Patients with CP had more pronounced pancreatic fibrosis (PF) (p < 0.001). Data showed a significant relationship between a high degree of PF and occurrence of diabetes (p = 0.006) and low fecal elastase-1 levels (p = 0.013). A statistically significant lower QOL was determined in patients with PF ≥ 50% and in the CP group. Conclusions: Sarcopenia and osteoporosis/osteopenia are highly prevalent among patients with chronic pancreatitis and pancreatic cancer, and CT- and MRI-based assessment of body composition and pancreatic fibrosis could be a potentially useful tool for routine detection of these significant metabolic changes.

Reliable and robust method for abdominal muscle mass quantification using CT/MRI: An explorative study in healthy subjects

Background

Quantification of abdominal muscle mass by cross-sectional imaging has been increasingly used to diagnose sarcopenia; however, the technical method for quantification has not been standardized yet. We aimed to determine an optimal method to measure the abdominal muscle area.

Methods

Among 50 consecutive subjects who underwent abdominal CT and MRI for possible liver donation, total abdominal muscle area (TAMA) and total psoas muscle area (TPA) at the L3 inferior endplate level were measured by two blinded readers. Inter-scan agreement between CT and MRI and inter-reader agreement between the two readers were evaluated using intraclass correlation coefficient (ICC) and within-subject coefficient of variation (WSCV). To evaluate the effect of measurement level, one reader measured TAMA and TPA at six levels from the L2 to L4 vertebral bodies.

Results

TAMA was a more reliable biomarker than TPA in terms of inter-scan agreement (ICC: 0.928 vs. 0.788 for reader 1 and 0.853 vs. 0.821 for reader 2, respectively; WSCV: 8.3% vs. 23.4% for reader 1 and 10.4% vs. 22.3% for reader 2, respectively) and inter-reader agreement (ICC: 0.986 vs. 0.886 for CT and 0.865 vs. 0.669 for MRI, respectively; WSCV: 8.2% vs. 16.0% for CT and 11.6% vs. 29.7% for MRI, respectively). In terms of the measurement level, TAMA did not differ from the L2_inf to L4_inf levels, whereas TPA increased with a decrease in measurement level.

Conclusions

TAMA is a better biomarker than TPA in terms of inter-scan and inter-reader agreement and robustness to the measurement level. CT was a more reliable imaging modality than MRI. Our results support the use of TAMA measured by CT as a standard biomarker for abdominal muscle area measurement.

Immunohistochemical phenotyping of T cells, granulocytes, and phagocytes in the muscle of cancer patients: association with radiologically defined muscle mass and gene expression

BACKGROUND

Inflammation is a recognized contributor to muscle wasting. Research in injury and myopathy suggests that interactions between the skeletal muscle and immune cells confer a pro-inflammatory environment that influences muscle loss through several mechanisms; however, this has not been explored in the cancer setting. This study investigated the local immune environment of the muscle by identifying the phenotype of immune cell populations in the muscle and their relationship to muscle mass in cancer patients.

METHODS

Intraoperative muscle biopsies were collected from cancer patients (n = 30, 91% gastrointestinal malignancies). Muscle mass was assessed histologically (muscle fiber cross-sectional area, CSA; μm²) and radiologically (lumbar skeletal muscle index, SMI; cm²/m² by computed tomography, CT). T cells (CD4 and CD8) and granulocytes/phagocytes (CD11b, CD14, and CD15) were assessed by immunohistochemistry. Microarray analysis was conducted in the muscle of a second cancer patient cohort.

RESULTS

T cells (CD3+), granulocytes/phagocytes (CD11b+), and CD3-CD4+ cells were identified. Muscle fiber CSA (μm²) was positively correlated (Spearman's r = > 0.45; p = < 0.05) with the total number of T cells, CD4, and CD8 T cells and granulocytes/phagocytes. In addition, patients with the smallest SMI exhibited fewer CD8 T cells within their muscle. Consistent with this, further exploration with gene correlation analyses suggests that the presence of CD8 T cells is negatively associated (Pearson's r = ≥ 0.5; p = <0.0001) with key genes within muscle catabolic pathways for signaling (ACVR2B), ubiquitin proteasome (FOXO4, TRIM63, FBXO32, MUL1, UBC, UBB, UBE2L3), and apoptosis/autophagy (CASP8, BECN1, ATG13, SIVA1).

CONCLUSION

The skeletal muscle immune environment of cancer patients is comprised of immune cell populations from the adaptive and innate immunity. Correlations of T cells, granulocyte/phagocytes, and CD3-CD4+ cells with muscle mass measurements indicate a positive relationship between immune cell numbers and muscle mass status in cancer patients. Further exploration with gene correlation analyses suggests that the presence of CD8 T cells is negatively correlated with components of muscle catabolism.

Deep learning-based muscle segmentation and quantification at abdominal CT: application to a longitudinal adult screening cohort for sarcopenia assessment

OBJECTIVE

To investigate a fully automated abdominal CT-based muscle tool in a large adult screening population.

METHODS

A fully automated validated muscle segmentation algorithm was applied to 9310 non-contrast CT scans, including a primary screening cohort of 8037 consecutive asymptomatic adults (mean age, 57.1±7.8 years; 3555M/4482F). Sequential follow-up scans were available in a subset of 1171 individuals (mean interval, 5.1 years). Muscle tissue cross-sectional area and attenuation (Hounsfield unit, HU) at the L3 level were assessed, including change over time.

RESULTS

Mean values were significantly higher in males for both muscle area (190.6±33.6 vs 133.3±24.1 cm², p<0.001) and density (34.3±11.1 HU vs 27.3±11.7 HU, p<0.001). Age-related losses were observed, with mean muscle area reduction of -1.5 cm²/year and attenuation reduction of -1.5 HU/year. Overall age-related muscle density (attenuation) loss was steeper than for muscle area for both sexes up to the age of 70 years. Between ages 50 and 70, relative muscle attenuation decreased significantly more in females (-30.6% vs -18.0%, p<0.001), whereas relative rates of muscle area loss were similar (-8%). Between ages 70 and 90, males lost more density (-22.4% vs -7.5%) and area (-13.4% vs -6.9%, p<0.001). Of the 1171 patients with longitudinal follow-up, 1013 (86.5%) showed a decrease in muscle attenuation, 739 (63.1%) showed a decrease in area, and 1119 (95.6%) showed a decrease in at least one of these measures.

CONCLUSION

This fully automated CT muscle tool allows for both individualized and population-based assessment. Such data could be automatically derived at abdominal CT regardless of study indication, allowing for opportunistic sarcopenia detection.

ADVANCES IN KNOWLEDGE

This fully automated tool can be applied to routine abdominal CT scans for prospective or retrospective opportunistic sarcopenia assessment, regardless of the original clinical indication. Mean values were significantly higher in males for both muscle area and muscle density. Overall age-related muscle density (attenuation) loss was steeper than for muscle area for both sexes, and therefore may be a more valuable predictor of adverse outcomes.

Prognostic Impact of Low Skeletal Muscle Mass on Major Adverse Cardiovascular Events in Coronary Artery Disease: A Propensity Score-Matched Analysis of a Single Center All-Comer Cohort

The impact of sarcopenia on atherosclerotic cardiovascular disease remains unclear. We aimed to investigate the prognostic impact of sarcopenia on coronary artery disease (CAD). A total of 475 patients with CAD who underwent successful percutaneous coronary intervention (PCI) and computed tomography (CT) were enrolled. The cross-sectional area of skeletal muscle at the first lumbar (L1) vertebral level was measured, and sex-specific cut-off values of L1 skeletal muscle index (L1 SMI; male <31.00 cm2/m2, female <25.00 cm2/m2) were obtained. The primary outcome was 3-year all-cause mortality and the secondary outcome was 3-year major adverse cardiovascular events (MACEs). Low L1 SMI was present in 141 (29.7%) of 475 patients. The incidence of all-cause mortality (23.7% vs. 5.9%, p < 0.001) and MACEs (39.6% vs. 11.8%, p < 0.001) was significantly higher in patients with low L1 SMI than in those with high L1 SMI. In multivariate analysis, low L1 SMI was an independent predictor of higher risk of all-cause mortality (hazard ratio (HR): 4.07; 95% confidence interval (CI): 1.95-8.45; p < 0.001) and MACEs (HR: 3.76; 95% CI: 2.27-6.23; p < 0.001). These findings remained consistent after propensity score-matched analysis with 91 patient pairs (C-statistic = 0.848). CT-diagnosed low skeletal muscle mass is a powerful predictor of adverse outcomes in patients with CAD undergoing PCI.

Quantification of fat and skeletal muscle tissue at abdominal computed tomography: associations between single-slice measurements and total compartment volumes

PURPOSE

Body composition is of great prognostic value in several severe diseases, including different types of cancer as well as cardiometabolic disorders. We aimed to investigate the correlations of skeletal muscle mass and abdominal adipose tissue compartments between volumetric and single-slice measurements to study the usefulness of several anatomical landmarks for estimation of total compartment volumes using abdominal CT-scans.

METHODS

In this retrospective study volumetric quantifications of paraspinal skeletal muscles (SM) and adipose tissue compartments (visceral adipose tissue, VAT; subcutaneous adipose tissue, SAT) were performed in 50 consecutive patients (26 male; mean age, 63 ± 15 years) who underwent abdominal multislice-CT for diagnostic purposes using an in-house software. Associations between total volumes of SM, VAT, and SAT with single-slice measurements at eight predefined anatomical landmarks (median intervertebral disk spaces T12/L1 to L5/S1; level of the umbilicus (U); level of the radix of the superior mesenteric artery (SMA)) were studied using correlation coefficients.

RESULTS

Statistical analysis revealed a strong association between single-slice measurements of adipose tissue compartments with total VAT and SAT volume (VAT: all r > 0.89, P < 0.001; SAT: all r > 0.95, P < 0.001). The strongest associations with total SM volume were found for single-slice measurements obtained at L3/4 (r = 0.94, P < 0.001) and were further improved by normalization to height (r = 0.98, P < 0.001).

CONCLUSIONS

Single-slice measurements of SM, VAT, and SAT at several anatomical landmarks are strongly associated with total compartment volumes and therefore allow for easy and simultaneous assessment of skeletal muscle mass and adipose tissue compartment volumes.

Cancer-Associated Malnutrition and CT-Defined Sarcopenia and Myosteatosis Are Endemic in Overweight and Obese Patients

BACKGROUND

Overweight/obese patients' large fat mass can mask the loss of skeletal muscle, which is associated with mortality in the oncology setting. We investigated the prevalence of computed tomography (CT)-defined sarcopenia and myosteatosis across different levels of nutrition risk assessed by the Patient-Generated Subjective Global Assessment Short Form (PG-SGA SF). We also evaluated whether the PG-SGA SF, sarcopenia, and myosteatosis were prognostic of overall survival.

METHODS

This was a prospective, observational study. Consecutive patients with body mass index ≥25.0 kg/m² with newly diagnosed head and neck cancer (any stage) or lung and gastrointestinal tract cancer (locally recurrent or metastatic) were screened at presentation to oncology clinics. Nutrition risk was assigned based on PG-SGA SF triage recommendations. Based on CT, patients were classified with sarcopenia and/or myosteatosis using published cutoffs. Survival analyses were conducted.

RESULTS

Patients (n=1157) were 63.6 ± 11.4 years, 64% male, and 61% had stage IV disease. Sarcopenia and myosteatosis were prevalent across PG-SGA SF nutrition risk categories (scores 0-1 [no risk; 36% sarcopenic; 44% myosteatotic], scores 2-3 [37%; 37%], scores 4-8 [40%; 41%], and scores ≥9 [high risk; 50%; 49%]). In multivariable survival analysis, PG-SGA SF scores ≥9 (hazard ratio [HR] 2.08, 95% confidence interval [CI] 1.66-2.60, P<0.001), sarcopenia (HR 1.25, 95% CI 1.06-1.46, P=0.006), and myosteatosis (HR 1.25, 95% CI 1.07-1.46, P<0.001) independently predicted reduced survival.

CONCLUSION

CT-defined sarcopenia and myosteatosis are prevalent across different levels of nutrition risk in overweight/obese patients with cancer. Assessment of skeletal muscle using CT adds prognostic value to the PG-SGA SF.

Diagnosis of Sarcopenia in Head and Neck Computed Tomography: Cervical Muscle Mass as a Strong Indicator of Sarcopenia

OBJECTIVES

Patients with head and neck cancer (HNC) have a high risk of sarcopenia, which is associated with poor prognosis. Skeletal-muscle area and index at the third lumbar (L3) vertebra level (L3MA and L3MI) are recommended for the detection of sarcopenia. However, L3 level is not included in many imaging protocols and there are no data for optimal levels and cutoffs for the diagnosis of sarcopenia in head and neck computed tomography (HNCT) scans. Our aim was to assess the relationship between cervical paravertebral muscle values and L3MI and to investigate optimal level to diagnose sarcopenia on HNCTs.

METHODS

Patients with HNC (n=159) who underwent positron emission tomography-CT for tumor staging were retrospectively analyzed. On CT images, paravertebral and sternocleidomastoid muscle areas at second (C2), third (C3), and fourth (C4) cervical vertebrae levels (C2MA, C3MA, C4MA, SCMA) and L3MA were measured. Cross-sectional areas were normalized for stature (muscle area/height square) and muscle index (C2MI, C3MI, C4MI, SCMI, L3MI) values were obtained. Spearman correlation and linear regression analyses were used for assessing correlations. To calculate the diagnostic performance of SCMI, C2MI, C3MI, and C4MI for the diagnosis of sarcopenia with respect to the cutoffs of L3MI, receiver operating characteristic (ROC) analysis was used.

RESULTS

Males had significantly higher muscle areas than females. Although C2MI, C3MI, C4MI, and SCMI values all showed very strong and significant correlation with L3MI (P<0.001). According to the ROC analysis, the best discriminative for sarcopenia was C3MI in males (area under curve [AUC], 0.967) and SCMI in females (AUC, 0.898).

CONCLUSION

C2MI, C3MI, C4MI, and SCMI values can be used as alternatives for the diagnosis of sarcopenia in routine HNCT examinations.

Cross-sectional and longitudinal assessment of muscle from regular chest computed tomography scans: L1 and pectoralis muscle compared to L3 as reference in non-small cell lung cancer

Background

Computed tomography (CT) is increasingly used in clinical research for single-slice assessment of muscle mass to correlate with clinical outcome and evaluate treatment efficacy. The third lumbar level (L3) is considered as reference for muscle, but chest scans generally do not reach beyond the first lumbar level (L1). This study investigates if pectoralis muscle and L1 are appropriate alternatives for L3.

Methods

CT scans of 115 stage IV non-small cell lung cancer patients were analyzed before and during tumor therapy. Skeletal muscle assessed at pectoralis and L1 muscle was compared to L3 at baseline. Furthermore, the prognostic significance of changes in muscle mass determined at different locations was investigated.

Results

Pearson’s correlation coefficient between skeletal muscle at L3 and L1 was stronger (r=0.90, P<0.001) than between L3 and pectoralis muscle (r=0.71, P<0.001). Cox regression analysis revealed that L3 (HR 0.943, 95% CI: 0.92–0.97, P<0.001) and L1 muscle loss (HR 0.954, 95% CI: 0.93–0.98, P<0.001) predicted overall survival, whereas pectoralis muscle loss did not.

Conclusion

L1 is a better alternative than pectoralis muscle to substitute L3 for analysis of muscle mass from regular chest CT scans.

Influence of Methods Used to Establish Sarcopenia Cutoff Values for Skeletal Muscle Measures Using Unenhanced and Contrast-Enhanced Computed Tomography Images

BACKGROUND

Multiple cutoff values of computed tomography (CT)-based skeletal muscle measures have been proposed, but there is currently no consensus used to identify sarcopenia. We aimed to evaluate the influence of statistical methods used to establish sarcopenia cutoff values and to examine the impact of contrast enhancement on the skeletal muscle measures.

METHODS

The skeletal muscle area (SMA) and muscle radiation attenuation (MRA) of 316 healthy individuals were measured on unenhanced CT images at the third lumbar vertebra level, and the skeletal muscle index (SMI) was SMA divided by height squared. Possible cutoff values were established using 2 methods: 5^th percentile of individuals aged 20-60 years or mean - 2 × SD of individuals aged 20-50 years. The concordance was assessed using Cohen's κ coefficients and McNemar test. The skeletal muscle parameters on 3 phases from 30 CT examinations were compared.

RESULTS

The concordance between the 2 methods was almost perfect (κ coefficients: 0.830-0.849) for low MRA but slight to moderate (κ coefficients: 0.189-0.591) for low SMI, especially in the men (P < 0.01). Compared with the unenhanced images, the mean SMA, SMI, and MRA on the contrast-enhanced images increased by 0.8%-1.7%, 0.8%-1.8%, and 14.8%-21.6% (all P < 0.001), respectively, and only the changes in MRA were clinically significant.

CONCLUSIONS

The methods for establishing cutoff values and contrast enhancement influence the identification of low SMI and low MRA, respectively. Thus, the definition of sarcopenia should include the standardized method for establishing cutoff values and the phase of CT for analysis.

Changes of computed tomography-based body composition after adrenalectomy in patients with endogenous hypercortisolism

CONTEXT

Data on longitudinal changes of computed tomography (CT)-determined visceral fat area (VFA), skeletal muscle area (SMA) and skeletal muscle radiodensity (SMD) after adrenalectomy are limited in patients with hypercortisolism.

OBJECTIVE

To examine the association of severity of cortisol excess and improvement of CT-based muscle and fat parameters after adrenalectomy.

DESIGN

Retrospective observational cohort study.

PATIENTS

One hundred thirty-four patients with overt Cushing's syndrome (CS; n = 39), mild autonomous cortisol excess (MACE; n = 57), or nonfunctioning adrenal tumour (NFAT; n = 38) at a tertiary endocrinology institution between 2006 and 2017 were included.

MEASUREMENTS

Changes in CT-determined VFA, visceral-to-subcutaneous fat ratio (VSR), SMA, skeletal muscle index (SMI), and SMD measured at the third lumbar vertebra (L3).

RESULTS

At baseline, CS patients had higher VFA, lower SMA, SMI and SMD values, compared to NFAT or MACE patients. Compared to NFAT, significant decreases in VFA and increases in SMA, SMI and SMD was observed in CS 1 year after adrenalectomy. In MACE, adjusted mean changes of SMD but not VFA, SMA or SMI differ significantly compared to NFAT (+8.9% vs -3.4%, P = 0.032). In a multivariate linear regression model, the increase by 1 μg/dL of post-dexamethasone serum cortisol at baseline was independently associated with greater reduction of VFA (-3.95%), VSR (-3.07%), and increase in SMD (+0.92%, P < 0.05 for all) after adrenalectomy.

CONCLUSIONS

The severity of cortisol excess was associated with greater improvement of L3 VFA, VSR and SMD 1 year after adrenalectomy. These CT-based markers may allow more objective assessment of treatment benefit at earlier stage.

Sarcopenia: revised European consensus on definition and diagnosis

Background

in 2010, the European Working Group on Sarcopenia in Older People (EWGSOP) published a sarcopenia definition that aimed to foster advances in identifying and caring for people with sarcopenia. In early 2018, the Working Group met again (EWGSOP2) to update the original definition in order to reflect scientific and clinical evidence that has built over the last decade. This paper presents our updated findings.

Objectives

to increase consistency of research design, clinical diagnoses and ultimately, care for people with sarcopenia.

Recommendations

sarcopenia is a muscle disease (muscle failure) rooted in adverse muscle changes that accrue across a lifetime; sarcopenia is common among adults of older age but can also occur earlier in life. In this updated consensus paper on sarcopenia, EWGSOP2: (1) focuses on low muscle strength as a key characteristic of sarcopenia, uses detection of low muscle quantity and quality to confirm the sarcopenia diagnosis, and identifies poor physical performance as indicative of severe sarcopenia; (2) updates the clinical algorithm that can be used for sarcopenia case-finding, diagnosis and confirmation, and severity determination and (3) provides clear cut-off points for measurements of variables that identify and characterise sarcopenia.

Conclusions

EWGSOP2's updated recommendations aim to increase awareness of sarcopenia and its risk. With these new recommendations, EWGSOP2 calls for healthcare professionals who treat patients at risk for sarcopenia to take actions that will promote early detection and treatment. We also encourage more research in the field of sarcopenia in order to prevent or delay adverse health outcomes that incur a heavy burden for patients and healthcare systems.