Adipose Tissue Cross-sectional Area Research Articles

Sarcopenia, adiposity and large discordance between cystatin C and creatinine-based estimated glomerular filtration rate in patients with cancer.

Creatinine-based estimated glomerular filtration rate (eGFRCRE) may overestimate kidney function in patients with sarcopenia. While cystatin C-based eGFR (eGFRCYS) is less affected by muscle mass, it may underestimate kidney function in patients with obesity. We sought to evaluate the relationship between body composition defined by computed tomography (CT) scans and discordance between creatinine, eGFRCRE and eGFRCYS in adult patients with cancer. This study is a cross-sectional study of consecutive adults with cancer with an abdominal CT scan performed within 90days of simultaneous eGFRCRE and eGFRCYS measurements between May 2010 and January 2022. Muscle and adipose tissue cross-sectional areas were measured at the level of the third lumbar vertebral body using a validated deep-learning pipeline. CT-defined sarcopenia was defined using independent sex-specific cut-offs for skeletal muscle index (<39cm2/m2 for women and <55cm2/m2 for men). High adiposity was defined as the highest sex-specific quartile of the total (visceral plus subcutaneous) adiposity index in the cohort. The primary outcome was eGFR discordance, defined by eGFRCYS>30% lower than eGFRCRE; the secondary outcome was eGFRCYS>50% lower than eGFRCRE. The odds of eGFR discordance were estimated using multivariable logistic regression modelling. Unadjusted spline regression was used to evaluate the relationship between skeletal muscle index and the difference between eGFRCYS and eGFRCRE. Of the 545 included patients (mean age 63±14years, 300 [55%] females, 440 [80.7%] non-Hispanic white), 320 (58.7%) met the criteria for CT-defined sarcopenia, and 136 (25%) had high adiposity. A total of 259 patients (48%) had >30% eGFR discordance, and 122 (22.4%) had >50% eGFR discordance. After adjustment for potential confounders, CT-defined sarcopenia and high adiposity were both associated with >30% eGFR discordance (adjusted odds ratio [aOR] 1.90, 95% confidence interval [CI] 1.12-3.24; aOR 2.01, 95% CI 1.15-3.52, respectively) and >50% eGFR discordance (aOR 2.34, 95% CI 1.21-4.51; aOR 2.23, 95% CI 1.19-4.17, respectively). A spline model demonstrated that as skeletal muscle index decreases, the predicted difference between eGFRCRE and eGFRCYS widens considerably. CT-defined sarcopenia and high adiposity are both independently associated with large eGFR discordance. Incorporating valuable information from body composition analysis derived from CT scans performed as a part of routine cancer care can impact the interpretation of GFR estimates.

Effects of two different paradigms of electrical stimulation exercise on cardio-metabolic risk factors after spinal cord injury. A randomized clinical trial.

To examine the combined effects of neuromuscular electrical stimulation-resistance training (NMES-RT) and functional electrical stimulation-lower extremity cycling (FES-LEC) compared to passive movement training (PMT) and FES-LEC in adults with SCI on (1) oxygen uptake (VO2), insulin sensitivity and glucose disposal in adults with SCI; (2) Metabolic and inflammatory biomarkers; (3) skeletal muscle, intramuscular fat (IMF) and visceral adipose tissue (VAT) cross-sectional areas (CSAs). Thirty-three participants with chronic SCI (AIS A-C) were randomized to 24 weeks of NMES-RT + FES or PMT + FES. The NMES-RT + FES group underwent 12 weeks of evoked surface NMES-RT using ankle weights followed by an additional 12 weeks of progressive FES-LEC. The control group, PMT + FES performed 12 weeks of passive leg extension movements followed by an additional 12 weeks of FES-LEC. Measurements were performed at baseline (BL; week 0), post-intervention 1 (P1; week 13) and post-intervention 2 (P2; week 25) and included FES-VO2 measurements, insulin sensitivity and glucose effectiveness using the intravenous glucose tolerance test; anthropometrics and whole and regional body composition assessment using dual energy x-ray absorptiometry (DXA) and magnetic resonance imaging to measure muscle, IMF and VAT CSAs. Twenty-seven participants completed both phases of the study. NMES-RT + FES group showed a trend of a greater VO2 peak in P1 [p = 0.08; but not in P2 (p = 0.25)] compared to PMT + FES. There was a time effect of both groups in leg VO2 peak. Neither intervention elicited significant changes in insulin, glucose, or inflammatory biomarkers. There were modest changes in leg lean mass following PMT + FES group. Robust hypertrophy of whole thigh muscle CSA, absolute thigh muscle CSA and knee extensor CSA were noted in the NMES-RT + FES group compared to PMT + FES at P1. PMT + FES resulted in muscle hypertrophy at P2. NMES-RT + FES resulted in a decrease in total VAT CSA at P1. NMES-RT yielded a greater peak leg VO2 and decrease in total VAT compared to PMT. The addition of 12 weeks of FES-LEC in both groups modestly impacted leg VO2 peak. The addition of FES-LEC to NMES-RT did not yield additional increases in muscle CSA, suggesting a ceiling effect on signaling pathways following NMES-RT. identifier NCT02660073.

CT Scan-Derived Muscle, But Not Fat, Area Independently Predicts Mortality in COVID-19

COVID-19 has demonstrated a highly variable disease course, from asymptomatic to severe illness and eventually death. Clinical parameters, as included in the 4C Mortality Score, can predict mortality accurately in COVID-19. Additionally, CT scan-derived low muscle and high adipose tissue cross-sectional areas (CSAs) have been associated with adverse outcomes in COVID-19. Are CT scan-derived muscle and adipose tissue CSAs associated with 30-day in-hospital mortality in COVID-19, independent of 4C Mortality Score? This was a retrospective cohort analysis of patients with COVID-19 seeking treatment at the ED of two participating hospitals during the first wave of the pandemic. Skeletal muscle and adipose tissue CSAs were collected from routine chest CT-scans at admission. Pectoralis muscle CSA was demarcated manually at the fourth thoracic vertebra, and skeletal muscle and adipose tissue CSA was demarcated at the first lumbar vertebra level. Outcome measures and 4C Mortality Score items were retrieved from medical records. Data from 578 patients were analyzed (64.6%men; mean age, 67.7 ± 13.5 years; 18.2%30-day in-hospital mortality). Patients who died within 30days demonstrated lower pectoralis CSA (median, 32.6 [interquartile range (IQR), 24.3-38.8] vs35.4 [IQR, 27.2-44.2]; P= .002) than survivors, whereas visceral adipose tissue CSA was higher (median, 151.1 [IQR, 93.6-219.7] vs112.9 [IQR, 63.7-174.1]; P= .013). In multivariate analyses, low pectoralis muscle CSA remained associated with 30-day in-hospital mortality when adjusted for 4C Mortality Score (hazard ratio, 0.98; 95%CI, 0.96-1.00; P= .038). CT scan-derived low pectoralis muscle CSA is associated significantly with higher 30-day in-hospital mortality in patients with COVID-19 independently of the 4C Mortality Score.

Body composition and Crohn's disease behavior: Is adiposity the main game changer?

ObjectiveWe investigated the association between body composition upon diagnosis and complicated phenotypes and time until surgery in patients with Crohn's disease (CD). MethodsWe conducted a retrospective cohort study including patients with CD who had a computed tomography enterography or a magnetic resonance enterography performed ≤6 mo of diagnosis. Skeletal muscle and visceral and subcutaneous adipose tissue cross-sectional areas were determined with computed tomography or magnetic resonance images at the third lumbar vertebral level, processed with the sliceOmatic (TomoVison, Magog, QC, Canada) and ABACS plugin. ResultsWe included 63 patients: 33 (52%) men, median age 35 y. Disease location (L) and behavior (B) according to the Montreal classification were L1 (ileal disease) = 28 (44%), L2 (colonic disease) = 13 (21%), L3(ileocolonic disease) = 18 (28%), L1 + L4 (ileal and isolated upper disease) = 1 (2%), L3 + L4 (ileocolonic and isolated upper disease) = 3 (5%), B1 (non-stricturing) = 39 (62%), B2 (stricturing) = 11 (17%), and B3 (penetrating)= 13 (21%); 20 (32%) patients had perianal disease. Visceral obesity was present in 12 (19%) patients and was associated with higher age of CD onset (median 60 versus 34 y; P = 0.002) and complicated disease behavior (B2 and B3) (66.7% versus 31.7%; P = 0.021). After adjusting for age and perianal disease, total adipose tissue was associated with a 4% increase in the odds of complicated behavior per 10 cm2 of total adipose tissue (odds ratio [OR] = 1.004; 95% confidence interval [CI], 1.00–1.008; P = 0.043). Median follow-up time was 3.35 y, during which 15 (24%) of patients underwent abdominal surgery. Visceral obesity was associated with 5.10-times higher risk of abdominal surgery (95% CI, 1.52–17.09; P = 0.008); after adjusting for disease behavior, visceral obesity maintained a near-significant association with a 2.90-times higher risk of surgery (95% CI, 0.83–10.08; P = 0.09). ConclusionTotal fat was associated with complicated disease phenotype and visceral obesity, with higher risk of abdominal surgery and shorter time until surgery.

Breast adipose tissue attenuation as a novel imaging biomarker for cardiometabolic risk.

Certain adipose tissue depots infer higher cardiometabolic risk than body mass index (BMI). To assess breast adipose tissue (BrAT) attenuation as a novel imaging biomarker for cardiometabolic risk. We studied 151 women (mean age = 56 ± 1 years) across the weight spectrum. BrAT attenuation, abdominal adipose tissue cross-sectional areas (CSA), and attenuation were quantified using non-contrast computed tomography (CT) scans. Cardiometabolic risk factors were assessed from medical records. BrAT attenuation was lower in obese women compared to lean women. BrAT attenuation was inversely associated with BMI, waist circumference, abdominal fat CSA, fasting glucose, and triglycerides (P ≤ 0.02), and positively associated with abdominal adipose tissue attenuation (P < 0.001). BrAT attenuation had a sensitivity of 90% but a specificity of only 35% in detecting the metabolic syndrome (area under the curve = 0.63). BrAT attenuation is associated with cardiometabolic risk markers and could serve as an imaging biomarker for opportunistic risk assessment in patients undergoing CT examination of the chest.

Validation of skeletal muscle and adipose tissue measurements using a fully automated body composition analysis neural network versus a semi-automatic reference program with human correction in patients with lung cancer

Rationale and objectivesTo validate skeletal muscle and adipose tissues cross sectional area (CSA) and densities between a fully automated neural network (test program) and a semi-automated program requiring human correction (reference program) for lumbar 1 (L1) and lumbar 2 (L2) CT scans in patients with lung cancer. Materials and methodsAgreement between the reference and test programs was measured using Dice-similarity coefficient (DSC) and Bland-Altman plots with limits of agreement within 1.96 standard deviation. ResultsA total of 49 L1 and 47 L2 images were analyzed from patients with lung cancer (mean age = 70.51 ± 9.48 years; mean BMI = 27.45 ± 6.06 kg/m2; 71% female, 55% self-identified as Black and 96% as non-Hispanic ethnicity). The DSC indicates excellent overlap (>0.944) or agreement between the two measurement methods for muscle, visceral adipose tissue (VAT) and subcutaneous adipose tissue (SAT) CSA and all tissue densities at L1 and L2. The DSC was lowest for intermuscular adipose tissue (IMAT) CSA at L1 (0.889) and L2 (0.919). ConclusionThe use of a fully automated neural network to analyze body composition at L1 and L2 in patients with lung cancer is valid for measuring skeletal muscle and adipose tissue CSA and densities when compared to a reference program. Further validation in a more diverse sample and in different disease and health states is warranted to increase the generalizability of the test program at L1 and L2.

Impact of Sarcopenic Obesity on Long-Term Cancer Outcomes and Postoperative Complications After Gastrectomy for Gastric Cancer

BackgroundThe prevalence of sarcopenia in gastric cancer (GC), although varying among the reported studies, is around 60%. In the last few years, it has been recognised that sarcopenia can also occur not only in patients with weight loss and low body weight, but also in patients with normal or increased body mass index. Therefore, the term sarcopenic obesity (SO) is a new definition that further expands the implications of altered body composition. The aim of this study was to assess the impact of SO on the perioperative morbidity and the survival of GC patients undergoing gastrectomy by evaluating body composition on CT images. MethodsPreoperative CT scans were obtained from all patients with a diagnosis of GC undergoing gastrectomy with curative intent between January 2012 and December 2019. Skeletal muscle mass index (SMMI) and visceral adipose tissue (VAT) cross-sectional area at the level of the transverse processes of the third lumbar vertebra (L3) were measured. Sarcopenia and obesity were defined according to sex-specific cut-off points. ResultsAfter analysing 190 patients, the prevalence of SO was 21.1% (40 patients) and sarcopenia was 14.7% (28 patients). Multivariate analysis showed that corporal composition was an independent factor of overall survival (p = 0.049). Logistic regression was performed to identify risk factors associated with postoperative complications. SO was identified as a risk factor for serious Clavien-Dindo complications > IIIb/IV [OR 2.82 (1.1–7.1); p = 0.028]. ConclusionSO was a risk factor for severe postoperative complications as well as worse long-term oncological after a gastrectomy for GC.

Healthy US population reference values for CT visceral fat measurements and the impact of IV contrast, HU range, and spinal levels

Measurements of visceral adipose tissue cross-sectional area and radiation attenuation from computed tomography (CT) scans provide useful information about risk and mortality. However, scan protocols vary, encompassing differing vertebra levels and utilizing differing phases of contrast enhancement. Furthermore, fat measurements have been extracted from CT using different Hounsfield Unit (HU) ranges. To our knowledge, there have been no large studies of healthy cohorts that reported reference values for visceral fat area and radiation attenuation at multiple vertebra levels, for different contrast phases, and using different fat HU ranges. Two-phase CT scans from 1,677 healthy, adult kidney donors (age 18–65) between 1999 and 2017, previously studied to determine healthy reference values for skeletal muscle measures, were utilized. Visceral adipose tissue cross-sectional area (VFA) and radiation attenuation (VFRA) measures were quantified using axial slices at T10 through L4 vertebra levels. T-tests were used to compare males and females, while paired t-tests were conducted to determine the effect (magnitude and direction) of (a) contrast enhancement and (b) different fat HU ranges on each fat measure at each vertebra level. We report the means, standard deviations, and effect sizes of contrast enhancement and fat HU range. Male and female VFA and VFRA were significantly different at all vertebra levels in both contrast and non-contrast scans. Peak VFA was observed at L4 in females and L2 in males, while peak VFRA was observed at L1 in both females and males. In general, non-contrast scans showed significantly greater VFA and VFRA compared to contrast scans. The average paired difference due to contrast ranged from 1.6 to − 8% (VFA) and 3.2 to − 3.0% (VFRA) of the non-contrast value. HU range showed much greater differences in VFA and VFRA than contrast. The average paired differences due to HU range ranged from − 5.3 to 22.2% (VFA) and − 5.9 to 13.6% (VFRA) in non-contrast scans, and − 4.4 to 20.2% (VFA) and − 4.1 to 12.6% (VFRA) in contrast scans. The − 190 to − 30 HU range showed the largest differences in both VFA (10.8% to 22.2%) and VFRA (7.6% to 13.6%) compared to the reference range (− 205 to − 51 HU). Incidentally, we found that differences in lung inflation result in very large differences in visceral fat measures, particularly in the thoracic region. We assessed the independent effects of contrast presence and fat HU ranges on visceral fat cross-sectional area and mean radiation attenuation, finding significant differences particularly between different fat HU ranges. These results demonstrate that CT measurements of visceral fat area and radiation attenuation are strongly dependent upon contrast presence, fat HU range, sex, breath cycle, and vertebra level of measurement. We quantified contrast and non-contrast reference values separately for males and females, using different fat HU ranges, for lumbar and thoracic CT visceral fat measures at multiple vertebra levels in a healthy adult US population.

P139 Body composition and Crohn’s disease behavior: Is adiposity the main game changer?

Abstract Background Introduction: Visceral fat has been associated with unfavorable outcomes in Crohn’s disease (CD) patients. We investigated the association between body composition upon diagnosis and complicated phenotypes and time until surgery in patients with CD. Methods retrospective cohort study including patients with CD who had a computed tomography enterography (CT) or an entero magnetic resonance (MR) performed within 6 months of diagnosis. Skeletal muscle, visceral and subcutaneous adipose tissue cross-sectional areas were determined with CT or MR images at L3 vertebrae level, after being processed with Slice-o-Matic (Tomovison) and ABCS module (applicable only to CT scan images). Logistic regression was used to assess predictors of disease behaviourand time until abdominal urgery was modeled with proportional hazards Cox models. Results We included 63 patients: 33(52%) men with median age of 35 years. Disease location and behaviour according to Montreal classification was as follows: L1=28(44%), L2=13(21%), L3=18(28%), L1+L4=1(2%), L3+L4=3(5%); B1=39(62%), B2=11(17%), B3=13(21%); 20(32%) patients had perianal disease. At diagnosis, 17(27%) patients were treated with corticosteroids. Anti-TNF agents were started in 8(13%) patients, azathioprine in 23(36%), combination therapy in 15(24%); 17(27%) patients did not start any medical therapy. Visceral obesity was present in 12(19%) patients at diagnosis. Visceral obesity was associated with higher age of CD onset (median 60 vs 34 years, p=0.002) and complicated disease behaviour(B2/B3) at diagnosis (66.7% vs 31.7%, p=0.021), with an approximately 4 times higher risk of complicated behaviour(OR=4.37, 95%IC=1.19–18.44, p=0.03).After adjusting for age and perianal disease, total adipose tissue (visceral and subcutaneous fat) remained statistically significant and was associated with a 4% increase in the odds of complicated behaviourat diagnosis per 10 cm2of total adipose tissue (OR 1.004,95%CI 1.00–1.008, p=0.043). Median follow-up time was 3.35 years, during which 15 (24%) of patients underwent abdominal surgery. Visceral obesity was associated with a 5.10 times higher risk of abdominal surgery during follow-up (95%CI 1.52–17.09, p=0.008); after adjusting to disease behaviour, visceral obesity maintained a near significant association with a 2.90 times higher risk of surgery (95%CI 0.83–10.08, p=0.09). Conclusion In our cohort of patients with newly diagnosed CD, total fat upon diagnosis seems to be associated with B2 and B3 disease phenotypes. Furthermore, visceral obesity was associated with a 5.10 times higher risk of abdominal surgery during follow-up and with a shorter time until surgery.

Body composition predictors of outcome in patients with COVID-19.

Background/ObjectiveObesity is a strong risk factor for adverse outcomes in patients hospitalized with COVID-19, however, the distribution of fat and the amount of muscle mass are more accurate risk factors than BMI. The objective of this study was to assess body composition measures obtained on opportunistic abdominal CTs as predictors of outcome in patients hospitalized with COVID-19. We hypothesized that elevated visceral and intermuscular adipose tissue would be associated with adverse outcome.Subjects/MethodsOur retrospective study was IRB-approved and HIPAA-compliant. The study group comprised 124 patients (median age: 68 years, IQR: 56, 77; 59 weeks, 65 months) who were admitted with COVID-19 to a single hospital and who had undergone abdominal CT for clinical purposes. Visceral adipose tissue (VAT), subcutaneous adipose tissue (SAT), intermuscular adipose tissue (IMAT), and paraspinal and abdominal muscle cross-sectional areas (CSA) were assessed. Clinical information including prognostic factors, time of admission to the intensive care unit (ICU) and time of death within 28 days were obtained. Multivariate time-to-event competing risk models were fitted to estimate the hazard ratio (HR) for a composite outcome of ICU admission/mortality associated with a one standard deviation increase in each body compositional measure. Each model was adjusted for age, sex, race, BMI, and cardiometabolic comorbidities.ResultsThere were 50 patients who were admitted to the ICU or deceased over a median time of 1 day [IQR 1, 6] from hospital admission. Higher VAT/SAT ratio (HR of 1.30; 95% CI 1.04–1.62, p = 0.022) and higher IMAT CSA (HR of 1.44; 95% CI 1.10–1.89, p = 0.008) were associated with a reduced time to ICU admission or death in adjusted models.ConclusionVAT/SAT and IMAT are predictors of adverse outcome in patients hospitalized with COVID-19, independent of other established prognostic factors. This suggests that body composition measures may serve as novel biomarkers of outcome in patients with COVID-19.

Computerized Tomography‐Derived Abdominal Body Fat Indices in a Healthy Young Midwestern US Population

Objective We report body composition via Computerized Tomography (CT)-derived adipose metric values for a young healthy population in the Midwestern United States across age, sex, and Body Mass Index (BMI) including Subcutaneous Adipose Tissue (SAT), Visceral adipose tissue (VAT), Sketelal Muscle (SM), and waist circumference (WC). Background To improve upon current inaccurate clinical assessments of body composition, national guidelines have recommended expanding diagnostic CT reporting to include body composition metrics which are currently not part of standard reporting. SAT, VAT, SM, and WC are easily measured in an automated format, providing precise measurement and better identification of adipose tissue distribution over traditional methods. However, there exists a paucity of normal reference values for these metrics. Data collected from a young and healthy population has been requested to allow for disease state comparisons. Aside from importance in body composition, these adipose metrics are also clinically relevant to other disease states, especially VAT with cardiovascular health. Hypothesis Pre-existing diagnostic CT scans be re-analyzed to obtain clinically relevant population-based data on body composition. Methods Pre-existing abdominal non-contrast computerized tomography (CT) scans from a young Midwestern population (19-40 years) were analyzed using Aquarius iNtuition software with automated identification of waist circumference and adipose tissue and skeletal muscle cross-sectional areas and densities. Normal health status and lack of chronic medical conditions among participants and Body Mass Index (BMI) were confirmed by automated screening and manual medical record review prior to analysis. Any abnormal or acute findings on CT led to exclusion. Results From 193 (45 male, 148 female) CT scans, for males, VAT surface area (SA) was 186.0 cm2 (SD=95.4) with attenuation (ATT) -96.7 HU (SD=8.6) and SAT SA was 265.6 cm2 (SD=191.5) with ATT -102.4 HU (SD=7.8); for females, VAT SA was 116.2 cm2 (SD=63.6) with ATT -93.8 HU (SD=8.7) and SAT SA was 309.6 cm2 (SD=186.2) with ATT -103.9 HU (SD=6.4). SM SA for males was 193.3 cm2 (SD=30.6) with ATT 40.4 HU (SD=8.4). SM SA for females was 127.9 cm2 (SD=21.9) with ATT 38.0 HU (SD=6.6) (Table 1). Pearson's correlation revealed BMI was statistically significant to the 0.01 level for a positive correlation with VAT, SAT, and SM SAs and a negative correlation for VAT, SAT, and SM ATTs (Figure 1 - VAT and BMI). Percentiles for sex-specific adipose tissue indices in accordance with body mass index were generated. An Analysis of Variance (ANOVA) revealed males have statistically significantly higher VAT SA than females (p<0.001). Additionally, males have lower VAT ATT than Women (p=0.048). Males also have significantly higher SM SA than females and higher SM ATT than Women (p=0.045). Conclusions Adipose tissue indices are newly generated for a young healthy Midwestern United States population. This study provides novel data as our population is young, devoid of chronic disease states, and from a population with minimal existing data. Such information has the ability to provide a baseline for comparison across disease states and body weights.

Subcutaneous and visceral adipose tissue in patients with primary and recurrent incisional hernia

PurposeVisceral obesity rather than body mass index has been reported to be associated with a higher incidence of incisional hernias. The aim of this study was to examine the relationship between CT measured adipose tissue and muscle in primary and recurrent incisional hernia.MethodsPatients with a ‘Primary’ or ‘Recurrent incisional hernia’ were obtained from a prospective cohort of patients who were being assessed for incisional hernia repair over a 2-year period. Computerised tomography (CT)-images were analysed using NIH Image-J software to quantify adipose tissue and skeletal muscle cross-sectional areas at the level of lumber vertebra 3/4 using standard Hounsfield units. To test inter-observer ‘absolute agreement’, each parameter was measured independently by two investigators and reliability analysis performed.ResultsThirty-six patients were included in the study: 15 had a Primary while 21 had a Recurrent incisional hernia. Both groups had similar baseline characteristics. Reliability analysis for CT-measured areas showed very high interclass correlation coefficient (ICC) between observers. Patients in the recurrent group had significantly greater subcutaneous adipose tissue (SAT) [median = 321.9cm2 vs 230.9cm2, p = 0.04] and visceral adipose tissue (VAT) [median = 221.1cm2 vs 146.8cm2, p = 0.03] than those in the primary group. There was no difference in skeletal muscle areas for right [median = 2.8cm2 vs 2.9cm2] and left [median = 3.7cm2 vs 4.1cm2] rectus muscles between groups.ConclusionOur study shows that patients with a recurrent incisional hernia have significantly more subcutaneous and visceral adipose tissue than those with a primary incisional hernia. Further studies in this area are required if we are to reduce the burden of recurrent hernia following repair of a primary incisional hernia.

Intramuscular Fat Influences Neuromuscular Activation of the Gluteus Medius in Older Adults.

The amount of tissue between the muscle and surface electromyography (sEMG) electrode influences the sEMG signals. Increased intramuscular adipose tissue (IMAT) of the hip abductor muscles negatively impacts balance in older individuals, but it is unknown if this is related to the ability to activate the muscles. The aim of this preliminary study was to investigate the influence of gluteus medius (GM) IMAT on sEMG amplitude during maximal voluntary isometric contractions (MVIC) of the hip abductors in older adults. We recruited 12 healthy community-dwelling older adults that underwent a spiral computerized tomography scan. High density lean (HDL), IMAT, and subcutaneous adipose tissue (SUBFAT) cross-sectional area of the GM were assessed. sEMG signal from the GM was recorded while participants performed an MVIC of the hip abductors. There was a negative correlation between GM activation and IMAT (r = −0.58, P = 0.046), and also SUBFAT (r = −0.78, P = 0.002) and a positive correlation with HDL (r = 0.73, P = 0.006). When controlling for SUBFAT, the partial correlations demonstrated a consistent negative correlation between GM activation and IMAT (r = −0.60, P = 0.050) but no relationship with HDL. The current results are important for helping to interpret the results from sEMG by accounting for IMAT. In conclusion, the neuromuscular activation of the GM may be reduced by the quantity of IMAT.

Skeletal muscle and adipose tissue changes in the first phase of treatment of pediatric solid tumors.

Body composition is increasingly recognized as an important factor in cancer outcomes. Use of computed tomography (CT) in cancer care provides the opportunity to accurately quantify whole‐body lean and adipose tissues from images at the third lumbar spine. We sought to substantiate the use of routinely captured, single‐slice chest CT images at the thoracic level for evaluation of skeletal muscle, residual lean tissue, and adiposity among pediatric solid tumor patients. We performed a retrospective analysis among children who underwent treatment for a solid tumor at Columbia University Irving Medical Center. Skeletal muscle (SM), residual lean tissue (RLT), and adipose tissue cross‐sectional areas (cm2) were analyzed at diagnosis and at first follow‐up for disease evaluation (6–14 weeks). Imaging analysis was performed utilizing slice‐O‐matic image analysis software. Of the 57 patients identified, 39 had chest CT imaging that included intervertebral level T12‐L1, and 22 also had concurrent imaging at L3. Correlation coefficients between body composition variables at T12‐L1 and L3 were strong (r = 0.93–0.98). Paired t‐test showed a significant decrease in SM (−4.2 ± 8.12, p = 0.003) and RLT (−10.7 ± 28.5, p = 0.025) as well as a trend toward a significant increase in visceral adipose tissue (3.10 ± 9.65, p = 0.052). Univariable analysis demonstrated a significant association between increasing age and increased SM loss (β = −0.496 with SE = 0.194, p = 0.011), and a lack of association between body mass index and body composition changes. We provide the first line of evidence that single‐slice images from routinely obtained chest CT scans provide a simple, readily available mechanism for assessing body composition in pediatric solid tumor patients. Adverse body composition changes were observed, particularly among adolescents and young adults.Precis: Changes in body composition can be detected via routine CT images in pediatric patients undergoing treatment for solid tumors.

Quantification of body composition in renal cell carcinoma patients: Comparing computed tomography and magnetic resonance imaging measurements

PurposeBody composition measures provide valuable information for prognostication and treatment election in cancer patients. We investigated the novel use of magnetic resonance imaging (MRI) for skeletal muscle and adipose tissue cross-sectional area measurements in preoperative renal cell carcinoma (RCC) patients. Materials and methodsRCC patients with pre-operative CT and MRI abdominal imaging were identified. Semi-automatic segmentation measurement of skeletal muscle area (SMA), intramuscular fat area (IMFA), visceral fat area (VFA), subcutaneous fat area (SFA), linear measurements of psoas, paraspinal muscles were performed. Pearson correlation coefficients, Bland-Altman plot analyses were done. Multivariable regression analysis examined the relationship between patient characteristics and skeletal muscle. ResultsImage analysis was performed on 58 RCC patients with preoperative CT and MRI imaging. For segmentation measures, r = 0.99, 0.99, 0.99, and 0.98 for SMA, IMFA, VFA, SFA, respectively, and 0.96 for linear measures of skeletal muscle. Bland-Altman analysis revealed a bias toward larger CT value for SMA (1.35 %), linear muscle measures (2.79 %), and SFA (10.34 %), and toward larger MRI values for IMFA (0.75 %) and VFA (5.81 %). ECOG ≥ 1 was associated with lower skeletal muscle than ECOG 0 for all measurements. ConclusionsStrong correlation of CT and MRI cross sectional measurements of skeletal muscle and adipose tissues supports the use of axial MRI images for comprehensive measurement of body composition. This has widespread implications for body composition research and cancer patient care.

Multilevel Body Composition Analysis on Chest Computed Tomography Predicts Hospital Length of Stay and Complications After Lobectomy for Lung Cancer: A Multicenter Study.

To investigate the impact of thoracic body composition on outcomes after lobectomy for lung cancer. Preoperative identification of patients at risk for adverse outcomes permits treatment modification. The impact of body composition on lung resection outcomes has not been investigated in a multicenter setting. A total of 958 consecutive patients undergoing lobectomy for lung cancer at 3 centers from 2014 to 2017 were retrospectively analyzed. Muscle and adipose tissue cross-sectional area at the fifth, eighth, and tenth thoracic vertebral body was quantified. Prospectively collected outcomes from a national database were abstracted to characterize the association between sums of muscle and adipose tissue and hospital length of stay (LOS), number of any postoperative complications, and number of respiratory postoperative complications using multivariate regression. A priori determined covariates were forced expiratory volume in 1 second and diffusion capacity of the lungs for carbon monoxide predicted, age, sex, body mass index, race, surgical approach, smoking status, Zubrod and American Society of Anesthesiologists scores. Mean patient age was 67 years, body mass index 27.4 kg/m2 and 65% had stage i disease. Sixty-three percent underwent minimally invasive lobectomy. Median LOS was 4 days and 34% of patients experienced complications. Muscle (using 30 cm2 increments) was an independent predictor of LOS (adjusted coefficient 0.972; P = 0.002), any postoperative complications (odds ratio 0.897; P = 0.007) and postoperative respiratory complications (odds ratio 0.860; P = 0.010). Sarcopenic obesity was also associated with LOS and adverse outcomes. Body composition on preoperative chest computed tomography is an independent predictor of LOS and postoperative complications after lobectomy for lung cancer.

Influence of body composition and muscle strength on outcomes after multimodal oesophageal cancer treatment.

BackgroundInfluence of sarcopenia in combination with other body composition parameters and muscle strength on outcomes after oesophageal surgery for oesophageal cancer remains unclear. The objectives were (i) to describe the incidence of sarcopenia in relation to adipose tissue quantity and distribution and muscle strength; (ii) to evaluate if neoadjuvant chemoradiation (nCRTx) influences body composition and muscle strength; and (iii) to evaluate the influence of body composition and muscle strength on post‐operative morbidity and long‐term survival.MethodsThis retrospective study included patients with oesophageal cancer who received nCRTx followed by surgery between January 2011 and 2016. Skeletal muscle, visceral, and subcutaneous adipose tissue cross‐sectional areas were calculated based on computed tomography scans, and muscle strength was measured using hand grip tests, 30 seconds chair stand tests, and maximal inspiratory and expiratory pressure tests prior to nCRTx and after nCRTx.ResultsA total of 322 patients were included in this study. Sarcopenia was present in 55.6% of the patients prior to nCRTx and in 58.2% after nCRTx (P = 0.082). Patients with sarcopenia had a significantly lower muscle strength and higher fat percentage. The muscle strength and incidence of sarcopenia increased while the mean body mass index and fat percentage decreased during nCRTx. A body mass index above 25 kg/m2 was associated with anastomotic leakage (P = 0.032). Other body composition parameters were not associated with post‐operative morbidity. A lower handgrip strength prior to nCRTx was associated with pulmonary and cardiac complications (P = 0.023 and P = 0.009, respectively). In multivariable analysis, a lower number of stands during the 30 seconds chair stand test prior to nCRTx (hazard ratio 0.93, 95% confidence interval 0.87–0.99, P = 0.017) and visceral adipose tissue of >128 cm2 after nCRTx (hazard ratio 1.81, 95% confidence interval 1.30–2.53, P = 0.001) were associated with worse overall survival.ConclusionsSarcopenia occurs frequently in patients with oesophageal cancer and is associated with less muscle strength and a higher fat percentage. Body composition changes during nCRTx did not influence survival. Impaired muscle strength and a high amount of visceral adipose tissue are associated with worse survival. Therefore, patients with poor fitness might benefit from preoperative nutritional and muscle strengthening guidance, aiming to increase muscle strength and decrease visceral adipose tissue. However, this should be confirmed in a large prospective study.

Visceral Adipose Tissue Radiodensity Is Linked to Prognosis in Hepatocellular Carcinoma Patients Treated with Selective Internal Radiation Therapy.

Hepatocellular carcinoma (HCC) constitutes the fourth leading cause of cancer-related mortality. Various factors, such as tumor size, tumor multiplicity, and liver function, have been linked to the prognosis of HCC. The aim of this study was to explore the prognostic significance of muscle, subcutaneous and visceral adipose tissue (VAT) mass, and radiodensity, in a cohort of 101 HCC patients treated with selective internal radiation therapy (SIRT). Muscle and adipose tissue cross sectional area (cm2/m2) and radiodensity, reported as the Hounsfield Unit (HU), were determined using pre-SIRT computed tomography images. Cox proportional hazard models and exact logistic regression were conducted to assess associations between body composition and adverse outcomes. Majority of the patients were male (88%) with a mean VAT radiodensity of −85 ± 9 HU. VAT radiodensity was independently associated with mortality (HR 1.05; 95% CI: 1.01–1.08; p = 0.01), after adjusting for cirrhosis etiology, Barcelona Clinic Liver Cancer stage, previous HCC treatment, and portal hypertension markers. Patients with a high VAT radiodensity of ≥–85 HU had a two times higher risk of mortality (HR 2.01, 95% CI 1.14–3.54, p = 0.02), compared to their counterpart. Clinical features of portal hypertension were more prevalent in patients with high VAT radiodensity. High VAT radiodensity was associated with severe adverse events after adjusting for confounding factors. High VAT radiodensity is independently associated with both increased mortality and severe adverse events in patients treated with SIRT. VAT radiodensity measurement might serve as an objective approach to identify patients who will experience the most benefit from SIRT.

Clinical evaluation of fully automated thigh muscle and adipose tissue segmentation using a U-Net deep learning architecture in context of osteoarthritic knee pain

ObjectiveSegmentation of thigh muscle and adipose tissue is important for the understanding of musculoskeletal diseases such as osteoarthritis. Therefore, the purpose of this work is (a) to evaluate whether a fully automated approach provides accurate segmentation of muscles and adipose tissue cross-sectional areas (CSA) compared with manual segmentation and (b) to evaluate the validity of this method based on a previous clinical study.Materials and methodsThe segmentation method is based on U-Net architecture trained on 250 manually segmented thighs from the Osteoarthritis Initiative (OAI). The clinical evaluation is performed on a hold-out test set bilateral thighs of 48 subjects with unilateral knee pain.ResultsThe segmentation time of the method is < 1 s and demonstrated high agreement with the manual method (dice similarity coeffcient: 0.96 ± 0.01). In the clinical study, the automated method shows that similar to manual segmentation (− 5.7 ± 7.9%, p < 0.001, effect size: 0.69), painful knees display significantly lower quadriceps CSAs than contralateral painless knees (− 5.6 ± 7.6%, p < 0.001, effect size: 0.73).DiscussionAutomated segmentation of thigh muscle and adipose tissues has high agreement with manual segmentations and can replicate the effect size seen in a clinical study on osteoarthritic pain.

Dietary manipulation and testosterone replacement therapy may explain changes in body composition after spinal cord injury: A retrospective case report.

BACKGROUNDReduced level of physical activity, high-fat diet and skeletal muscle atrophy are key factors that are likely to contribute to deleterious changes in body composition and metabolic following spinal cord injury (SCI). Reduced caloric intake with lowering percentage macronutrients of fat and increasing protein intake may likely to improve body composition parameters and decrease ectopic adiposity after SCI.AIMTo highlight the effects of dietary manipulation and testosterone replacement therapy (TRT) on body composition after SCIMETHODSA 31-year-old male with T5 SCI was administered transdermal TRT daily for 16 wk. Caloric intake and percentage macronutrients were analyzed using dietary recalls. Magnetic resonance imaging and dual-energy x-ray absorptiometry were used to measure changes in body composition.RESULTSCaloric intake and fat percentage were reduced by 445 kcal/d and 6.5%, respectively. Total body weight decreased by 8%, body fat decreased by 29%, and lean mass increased by 7%. Thigh subcutaneous adipose tissue cross-sectional area was reduced by 31%.CONCLUSIONManipulation of caloric intake, fat percentage, and protein percentage may have influenced body composition after SCI.