Estimating dual-energy X-ray absorptiometry-derived total body skeletal muscle mass using single-slice abdominal magnetic resonance imaging in obese subjects with and without diabetes: a pilot study

Prediction of whole body composition utilizing cross-sectional abdominal imaging in pediatrics

BACKGROUND

Although body composition is an important determinant of pediatric health outcomes, we lack tools to routinely assess it in clinical practice. We define models to predict whole-body skeletal muscle and fat composition, as measured by dual X-ray absorptiometry (DXA) or whole-body magnetic resonance imaging (MRI), in pediatric oncology and healthy pediatric cohorts, respectively.

METHODS

Pediatric oncology patients (≥5 to ≤18 years) undergoing an abdominal CT were prospectively recruited for a concurrent study DXA scan. Cross-sectional areas of skeletal muscle and total adipose tissue at each lumbar vertebral level (L1-L5) were quantified and optimal linear regression models were defined. Whole body and cross-sectional MRI data from a previously recruited cohort of healthy children (≥5 to ≤18 years) was analyzed separately.

RESULTS

Eighty pediatric oncology patients (57% male; age range 5.1-18.4 y) were included. Cross-sectional areas of skeletal muscle and total adipose tissue at lumbar vertebral levels (L1-L5) were correlated with whole-body lean soft tissue mass (LSTM) (R²= 0.896-0.940) and fat mass (FM) (R²= 0.874-0.936) (p < 0.001). Linear regression models were improved by the addition of height for prediction of LSTM (adjusted R² = 0.946-0^.971; p < 0.001) and by the addition of height and sex (adjusted R² = 0.930-0.953) (p < 0^.001)) for prediction of whole body FM. High correlation between lumbar cross-sectional tissue areas and whole-body volumes of skeletal muscle and fat, as measured by whole-body MRI, was confirmed in an independent cohort of 73 healthy children.

CONCLUSION

Regression models can predict whole-body skeletal muscle and fat in pediatric patients utilizing cross-sectional abdominal images.

Adding liver R2* quantification to proton density fat fraction MRI of vertebral bone marrow improves the prediction of osteoporosis

OBJECTIVES

To assess the predictive value of the combination of bone marrow (BM) proton density fat fraction (PDFF) and liver R2* for osteopenia and osteoporosis and the additional role of liver R2*.

METHODS

A total of 107 healthy women were included between June 2019 and January 2021. Each participant underwent dual-energy X-ray absorptiometry (DXA) and chemical shift-encoded 3.0-T MRI. PDFF measurements were performed for each lumbar vertebral body, and R2* measurements were performed in liver segments. Agreement among measurements was assessed by Bland-Altman analysis. Receiver operating characteristic (ROC) curves were generated to select optimised cut-offs for BM PDFF and liver R2*. Univariable and multivariable logistic regressions were performed. The C statistic and continuous net reclassification improvement (NRI) were adopted to explore the incremental predictive ability of liver R2*.

RESULTS

Bone mass decreased in 42 cases (39.3%) and nonbone mass decreased in 65 cases (60.7%). There were significant differences among the age groups, menopausal status groups, PDFF > 45.0% groups, and R2* > 67.7 groups. Each measurement had good reproducibility. The odds ratios (95% CIs) were 4.05 (1.22-13.43) for PDFF and 4.34 (1.41-13.35) for R2*. The C statistic (95% CI) without R2* was 0.888 (0.827-0.950), and with R2* was 0.900 (0.841-0.960). The NRI resulting from the combination of PDFF and R2* was 75.6% (p < 0.01).

CONCLUSION

The predictive improvement over the use of BM PDFF and other traditional risk factors demonstrates the potential of liver R2* as a biomarker for osteopenia and osteoporosis in healthy women.

KEY POINTS

• Liver R2* is a biomarker for the assessment of osteopenia and osteoporosis. • Liver R2* improved the ability to predict osteopenia and osteoporosis. • The intra- and interobserver measurements showed high agreement.

Sarcopenia in Children with Solid Organ Tumors: An Instrumental Era

Sarcopenia has recently been studied in both adults and children and was found to be a prognostic marker for adverse outcome in a variety of patient groups. Our research showed that sarcopenia is a relevant marker in predicting outcome in children with solid organ tumors, such as hepatoblastoma and neuroblastoma. This was especially true in very ill, high-risk groups. Children with cancer have a higher likelihood of ongoing loss of skeletal muscle mass due to a mismatch in energy intake and expenditure. Additionally, the effects of cancer therapy, hormonal alterations, chronic inflammation, multi-organ dysfunction, and a hypermetabolic state all contribute to a loss of skeletal muscle mass. Sarcopenia seems to be able to pinpoint this waste to a high degree in a new and objective way, making it an additional tool in predicting and improving outcome in children. This article focuses on the current state of sarcopenia in children with solid organ tumors. It details the pathophysiological mechanisms behind sarcopenia, highlighting the technical features of the available methods for measuring muscle mass, strength, and function, including artificial intelligence (AI)-based techniques. It also reviews the latest research on sarcopenia in children, focusing on children with solid organ tumors.

Prognostic Role of Preoperative Sarcopenia Evaluation of Cervical Muscles with Long-Term Outcomes of Patients with Oral Squamous Cell Carcinoma

Accumulating evidence has shown that sarcopenia in patients with oral squamous cell carcinoma (OSCC) is at a risk of poor prognosis. There is no universal consensus on how to assess sarcopenia in patients with OSCC in daily practice. It is important to validate the usefulness of sarcopenia assessment from cervical muscles, which are frequently used in routine clinical practice in patients with OSCC. In this study, we investigated whether preoperative lumbar (L3) skeletal muscle mass and adiposity in OSCC patients were associated with cervical (C3) skeletal muscle mass and adiposity from CT measurements. We also investigated whether skeletal muscle mass and adiposity in the C3 muscles were associated with survival rates in patients with OSCC. We demonstrated that both the quality and quantity of muscle between the C3 and L3 levels were positively correlated with each other. We also demonstrated that the survival rates in patients with low sternocleidomastoid muscle mass index, high processus spinosus muscle-intramuscular adipose tissue content, and the combination of both were significantly lower than those in the controls. These results suggest that the assessment of sarcopenia from multiple neck muscles by preoperative CT measurements may be useful in predicting the prognosis of patients with OSCC.

Measuring Muscle Mass and Strength in Obesity: a Review of Various Methods

Lower muscle mass in populations with obesity is associated obesity-related diseases like hypertension and type 2 diabetes mellitus. Bariatric surgery leads to sustained weight loss. During the weight reduction, loss of muscle should be minimized. Thus reliable quantification of muscle mass is much needed and therefore the also the need for validated methods. Imaging methods, magnetic resonance imaging and computed tomography scan, have been the gold standard for many years. However, these methods are costly and have limitations such as the maximum weight. Dual-energy X-ray absorptiometry is currently the most used alternative. Other, less expensive methods are very limited in their validation in populations with morbid obesity. This narrative review summarizes the current knowledge regarding measuring muscle mass and strength in obesity.

Circulating 20S proteasome for assessing protein energy wasting syndrome in hemodialysis patients

Protein energy wasting (PEW) including muscle atrophy is a common complication in chronic hemodialysis patients. The ubiquitin proteasome system (UPS) is the main proteolytic system causing muscle atrophy in chronic kidney disease and proteasome 20S is the catalytic component of the UPS. Circulating proteasome 20S (c20S proteasome) is present in the blood and its level is related to disease severity and prognosis in several disorders. We hypothesized that c20S proteasome could be related with muscle mass, other PEW criteria and their evolution in hemodialysis patients. Stable hemodialysis patients treated at our center for more than 3 months were followed over 2 years. C20S proteasome assay was performed at baseline. Biological and clinical data were collected, muscle mass was assessed by multi-frequency bio-impedancemetry, and nutritional scores were calculated at baseline, 1 year and 2 years. Hospitalizations and mortality data were collected over the 2 years. Forty-nine patients were included. At baseline, the c20S proteasome level was 0.40[0.26–0.55] μg/ml. Low muscle mass as defined by a lean tissue index (LTI) < 10th in accordance with the International Society of Renal Nutrition and Metabolism guidelines was observed in 36% and PEW in 62%. Increased c20S proteasome levels were related with LTI at baseline (R = 0.43, p = 0.004) and with its 2 year-variation (R = -0.56, p = 0.003). Two-year survival rate was not different between higher and lower c20S proteasome values (78.9 vs 78.4%, p = 0.98 log-rank test). C20S proteasome is not a good marker for assessing nutritional status in hemodialysis patients and predicting patient outcomes.

The effects of testosterone administration on muscle areas of the trunk and pelvic floor in hysterectomized women with low testosterone levels: proof-of-concept study

OBJECTIVE

The aim of this study was to determine the effect of testosterone administration on trunk and pelvic floor muscle area in women with low testosterone levels.

METHODS

Participants were hysterectomized women with total testosterone<31 ng/dL and/or free testosterone<3.5 pg/mL; participating in the Testosterone Dose Response in Surgically Menopausal Women (TDSM) trial. All participants received a standardized transdermal estradiol regimen during the 12-week run-in period, and were then randomized to receive weekly intramuscular injections of placebo, or 3, 6.25, 12.5, or 25 mg testosterone enanthate for 24 weeks. Muscle areas of the trunk and pelvis were measured at baseline and end of treatment using 1.5 Tesla magnetic resonance imaging. Total and free testosterone levels were measured by liquid chromatography-tandem mass spectrometry and equilibrium dialysis, respectively. Testosterone effect on muscle areas was analyzed using linear regression models.

RESULTS

A total of 24 women who had available baseline and posttreatment magnetic resonance imaging were included in the analysis. Increased cross-sectional areas of the paraspinal, psoas, and abdominal wall muscles were seen after testosterone administration. The estimated mean change (95% CI; P value) between treatment groups was 4.07 cm (1.26-6.88; P = 0.007) for paraspinal, 1.60 cm (0.10-3.09; P = 0.038) for psoas major, and 7.49 cm (1.96-13.02; P = 0.011) for abdominal wall muscles. Increases in psoas muscle area were significantly associated with changes in free testosterone concentrations. No significant changes in obturator internus and pelvic floor muscle areas were observed.

CONCLUSION

Short-term testosterone administration in women with low testosterone levels was associated with increased trunk muscle area.

Russian consensus on exo- and endocrine pancreatic insufficiency after surgical treatment

The Russian consensus on exo- and endocrine pancreatic insufficiency after surgical treatment was prepared on the initiative of the Russian "Pancreatic Club" on the Delphi method. His goal was to clarify and consolidate the opinions of specialists on the most relevant issues of diagnosis and treatment of exo- and endocrine insufficiency after surgical interventions on the pancreas. An interdisciplinary approach is provided by the participation of leading gastroenterologists and surgeons.

Muscles of the trunk and pelvis are responsive to testosterone administration: data from testosterone dose-response study in young healthy men

Testosterone dose-dependently increases appendicular muscle mass. However, the effects of testosterone administration on the core muscles of the trunk and the pelvis have not been evaluated. The present study evaluated the effects of testosterone administration on truncal and pelvic muscles in a dose-response trial. Participants were young healthy men aged 18-50 years participating in the 5α-Reductase (5aR) Trial. All participants received monthly injections of 7.5 mg leuprolide acetate to suppress endogenous testosterone production and weekly injections of 50, 125, 300, or 600 mg of testosterone enanthate and were randomized to receive either 2.5 mg dutasteride (5aR inhibitor) or placebo daily for 20 weeks. Muscles of the trunk and the pelvis were measured at baseline and the end of treatment using 1.5-Tesla magnetic resonance imaging. The dose effect of testosterone on changes in the psoas major muscle area was the primary outcome; secondary outcomes included changes in paraspinal, abdominal, pelvic floor, ischiocavernosus, and obturator internus muscles. The association between changes in testosterone levels and muscle area was also assessed. Testosterone dose-dependently increased areas of all truncal and pelvic muscles. The estimated change (95% confidence interval) of muscle area increase per 100 mg of testosterone enanthate dosage increase was 0.622 cm² (0.394, 0.850) for psoas; 1.789 cm² (1.317, 2.261) for paraspinal muscles, 2.530 cm² (1.627, 3.434) for total abdominal muscles, 0.455 cm² (0.233, 0.678) for obturator internus, and 0.082 cm² (0.003, 0.045) for ischiocavernosus; the increase in these volumes was significantly associated with the changes in on-treatment total and free serum testosterone concentrations. In conclusion, core muscles of the trunk and pelvis are responsive to testosterone administration. Future trials should evaluate the potential role of testosterone administration in frail men who are predisposed to falls and men with pelvic floor dysfunction.

Low muscle mass at initiation of anti-TNF therapy for inflammatory bowel disease is associated with early treatment failure: a retrospective analysis

BACKGROUND/OBJECTIVES

Delayed treatment failure occurs in a significant proportion of inflammatory bowel disease (IBD) patients treated with tumor necrosis factor-alpha (TNF) antagonists. Identification of predictors of loss of response (LOR) may help to optimize therapy. We sought to determine whether body composition parameters at the commencement of anti-TNF therapy were associated with earlier treatment failure.

SUBJECTS/METHODS

A retrospective cohort study was performed on 68 patients who had undergone cross-sectional abdominal imaging coincident with the commencement of anti-TNF drugs. Analysis of the images at the third lumbar vertebra was performed using standard techniques to determine cross-sectional areas of skeletal muscle (SM), visceral adipose tissue, subcutaneous adipose tissue and intermuscular adipose tissue. Treatment failure was defined as: post-induction hospital admission or surgery for IBD, escalation of TNF dose or immunosuppressants for clinical LOR, emergence of a new fistula or Crohn's Disease Activity Index (CDAI) >150.

RESULTS

Two-thirds of patients had myopenia. Patients with less than gender-specific median SM area had a median time to failure of 520 (s.d. 135) days compared to 1100 (s.d. 151) days for those with more than median SM area (P=0.036). No difference was found in disease duration, inflammatory markers or CDAI between quartiles of SM area. No relation between outcomes and measures of adipose tissue, weight or body mass index was observed.

CONCLUSIONS

Identifying low muscle mass at anti-TNF induction as a risk factor for treatment failure may contribute to a more tailored approach to IBD therapy.

Weight and Body Composition Compartments do Not Predict Therapeutic Thiopurine Metabolite Levels in Inflammatory Bowel Disease

OBJECTIVES:

Thiopurine drugs are the most commonly used steroid-sparing therapies in moderate-to-severe inflammatory bowel disease (IBD). Their complex metabolism and their narrow therapeutic windows means that optimal dosing is difficult. However, weight-based dosing is the norm. Similar antimetabolites are dosed by body composition parameters. In IBD, treatment response and toxicity has been shown to correlate with thiopurine metabolite levels. We sought to determine whether weight or body composition parameters predicted therapeutic 6-thioguanine nucleotide (6TGN) or toxic 6-methylmercaptopurine (6MMP) levels.

METHODS:

This single-center retrospective cohort study identified 66 IBD patients who had body composition analysis and thiopurine metabolite levels tested. Statistical analysis was performed using Spearman correlation, Kruskal–Wallis, Mann–Whitney, and unpaired t tests and receiver-operator operating characteristic curves. A P value of <0.05 was considered significant.

RESULTS:

No correlation was identified between 6TGN and any body composition parameters, absolute drug dose or drug dose/kg of fat mass, fat-free mass (FFM), subcutaneous adipose tissue area, or visceral adipose tissue area. However, 6MMP correlated with azathioprine dose, thiopurine dose/kg of body weight, and with several body composition parameters.

CONCLUSIONS:

No relationship was found between therapeutic metabolite levels and weight or body composition compartments. Higher thiopurine doses, especially in relation to FFM, are associated with higher levels of potentially hepatotoxic 6MMP and shunting toward this metabolite. Conventional weight-based dosing to attain therapeutic metabolite levels appears unreliable and may be replaced by metabolite level testing.

Feasibility of using head and neck CT imaging to assess skeletal muscle mass in head and neck cancer patients

OBJECTIVES

Patients with head and neck cancer (HNC) have a higher risk of malnutrition and sarcopenia, which is associated with adverse clinical outcome. As abdominal CT-imaging is often used to detect sarcopenia, such scans are rarely available in HNC patients, possibly explaining why no studies investigate the effect of sarcopenia in this population. We correlated skeletal muscle mass assessed on head and neck CT-scans with abdominal CT-imaging.

METHODS

Head and neck, and abdominal CT-scans of trauma (n=51) and HNC-patients (n=52) were retrospectively analyzed. On the head and neck CT-scans, the paravertebral and sternocleidomastoid muscles were delineated. On the abdominal CT-scans, all muscles were delineated. Cross-sectional area (CSA) of the muscles at the level of the C3 vertebra was compared to CSA at the L3 level using linear regression. A multivariate linear regression model was established.

RESULTS

HNC-patients had significantly lower muscle CSA than trauma patients (37.9 vs. 45.1cm², p<0.001, corrected for sex and age). C3 muscle CSA strongly predicted L3 muscle CSA (r=0.785, p<0.001). This correlation was stronger in a multivariate model including sex, age and weight (r=0.891, p<0.001).

DISCUSSION

Assessment of skeletal muscle mass on head and neck CT-scans is feasible and may be an alternative to abdominal CT-imaging. This method allows assessment of sarcopenia using routinely performed scans without additional imaging or additional patient burden. Identifying sarcopenic patients may help in treatment selection, or to select HNC patients for physiotherapeutic or nutritional interventions to improve their outcome.

CT Measures of Bone Mineral Density and Muscle Mass Can Be Used to Predict Noncancer Death in Men with Prostate Cancer

Purpose To determine if computed tomographic (CT) metrics of bone mineral density and muscle mass can improve the prediction of noncancer death in men with localized prostate cancer. Materials and Methods Institutional review board approval was obtained, with waiver of informed consent. All patients who underwent radiation therapy for localized prostate cancer between 2001 and 2012 with height, weight, and past medical history documented and who underwent CT that included the L4-5 vertebral interspace were included. On a single axial CT section obtained at the mid-L5 level, the mean CT attenuation of the trabecular bone of the L5 vertebral body (L5_HU) was measured. The height-normalized psoas cross-sectional area (Psoas_L4-5) was measured on a single CT section obtained at the L4-5 vertebral interface. Multivariable Cox proportional hazards models were used to assess effects on noncancer death. By using parameter estimates from an adjusted model, a prognostic index for prediction of noncancer death was generated and compared with age-adjusted Charlson Comorbidity Index (CCI) by using the Harrell c statistic. Results Six hundred fifty-three men met the inclusion criteria. Prostate cancer risk grouping, androgen deprivation, race, age-adjusted CCI, L5_HU, and Psoas_L4-5 were included in a multivariable model. Age-adjusted CCI (hazard ratio [HR] = 1.36, P < .001), L5_HU (HR = 2.88 for L5_HU < 105 HU, HR = 1.42 for 105 HU ≤ L5_HU ≤ 150 HU, P < .001), Psoas_L4-5 (HR = 1.95 for Psoas_L4-5 < 7.5 cm²/m², P = .003), and race (HR = 1.68 for African American race, HR = 1.77 for other nonwhite race, P = .019) were independent predictors of noncancer death. The prognostic index yielded a c value of 0.747 for the prediction of noncancer death versus 0.718 for age-adjusted CCI alone. Conclusion L5_HU and Psoas_L4-5, which are surrogates for bone mineral density and muscle mass, respectively, were independent predictors of noncancer death. The prognostic index that incorporated these measures with the CCI was associated with improved accuracy for prediction of noncancer death. ^© RSNA, 2016 Online supplemental material is available for this article.

Body composition analysis using abdominal scans from routine clinical care in patients with Crohn's Disease

OBJECTIVE

Crohn's Disease is associated with body composition changes, which have important treatment and prognostic implications. Measurement of body composition usually requires dedicated scanning or measurement, with retrospective analysis of existing datasets impossible. We sought to determine whether single slice analysis of abdominal scans, obtained during routine clinical care, in patients with Crohn's Disease accurately predicts body composition compartments.

MATERIALS AND METHODS

Abdominal CT images of patients with Crohn's disease were analyzed and comparison was made with total body fat-free mass, total body fat mass, femoral neck t-score, and other parameters reported from DXA, the reference method.

RESULTS

Thirty-seven subjects were identified, 15 male and 22 female, with a mean age of 43.8 years. There was significant correlation (Pearson r = 0.923, p < 0.001) between skeletal muscle area from CT and total fat-free mass measured by DXA. Similarly, total body fat mass correlated strongly (r = 0.928, p < 0.0001) with subcutaneous fat area. In this cohort of ambulatory Crohn's Disease patients, low muscle mass/sarcopenia was prevalent and predictive of lower bone mineral density.

CONCLUSIONS

Fat mass, fat-free mass, and appendicular skeletal muscle index can be predicted by analysis of a single CT slice in patients with Crohn's Disease. Similar to published data from healthy subjects, the L3 vertebral body level provided the most robust correlation with most parameters. This study represents the first published use of routinely obtained abdominal imaging to demonstrate this relationship - and to predict body composition components - in patients with inflammatory bowel disease.