Percentiles for skeletal muscle index, area and radiation attenuation based on computed tomography imaging in a healthy Caucasian population. Eur J Clin Nutr. 2018;72:288-296. [PMID: 29242526 PMCID: PMC5842880 DOI: 10.1038/s41430-017-0034-5]

Prognostic Value of Sarcopenia in Metastatic Colorectal Cancer Patients Treated with Trifluridine/Tipiracil

Sarcopenia is common in metastatic colorectal cancer (mCRC), increases the risk of treatment-related toxicity and reduces survival. Trifluridine/tipiracil (TT) chemotherapy significantly improved survival in refractory mCRC patients, but the prognostic and predictive role of pretherapeutic sarcopenia and variation in the skeletal muscle index (SMI) during this treatment has not been investigated so far. In this retrospective, observational study, clinical data on mCRC patients treated with TT at six cancer centres in Poland were collected. Computed tomography (CT) scans acquired at the time of initiation of TT (CT1) and on the first restaging (CT2), were evaluated. SMI was assessed based on the skeletal muscle area (SMA) at the level of the third lumbar vertebra. Progression-free survival (PFS) and overall survival (OS) were calculated from the treatment start. Neither initial sarcopenia nor ≥5% skeletal mass loss (SML) between CT1 and CT2 had a significant effect on PFS in treated patients (p = 0.5526 and p = 0.1092, respectively). In the multivariate analysis, reduced OS was found in patients with ≥5% SML (HR: 2.03 (1.11–3.72), p = 0.0039). We describe the prognostic role of sarcopenia beyond second line treatment and analyze other factors, such as performance status, tumor histological differentiation or carcinoembryonic antigen level that could predict TT treatment response.

Are Sarcopenia and Myosteatosis in Elderly Patients with Pelvic Ring Injury Related to Mortality, Physical Functioning and Quality of Life?

The purpose of this study was to evaluate the prevalence of sarcopenia and/or myosteatosis in elderly patients with pelvic ring injuries and their influence on mortality, patient-perceived physical functioning and quality of life (QoL). A multicenter retrospective cohort study was conducted including elderly patients aged ≥ 65 treated for a pelvic ring injury. Cross-sectional computed tomography (CT) muscle measurements were obtained to determine the presence of sarcopenia and/or myosteatosis. Kaplan–Meier analysis was used for survival analysis, and Cox proportional hazards regression analysis was used to determine risk factors for mortality. Patient-reported outcome measures for physical functioning (SMFA) and QoL (EQ-5D) were used. Multivariable linear regression analyses were used to determine the effect of sarcopenia and myosteatosis on patient-perceived physical functioning and QoL. Data to determine sarcopenia and myosteatosis were available for 199 patients, with a mean follow-up of 2.4 ± 2.2 years: 66 patients (33%) were diagnosed with sarcopenia and 65 (32%) with myosteatosis, while 30 of them (15%) had both. Mortality rates in patients at 1 and 3 years without sarcopenia and myosteatosis were 13% and 21%, compared to 11% and 36% in patients with sarcopenia, 17% and 31% in patients with myosteatosis and 27% and 43% in patients with both. Higher age at the time of injury and a higher Charlson Comorbidity Index (CCI) were independent risk factors for mortality. Patient-reported mental and emotional problems were significantly increased in patients with sarcopenia.

Impact of Muscle Mass on Survival in Patients with Sepsis: A Systematic Review and Meta-Analysis

INTRODUCTION

The aim of this study is to investigate the association between loss of muscle mass and prognosis of sepsis.

METHODS

Six databases, including PubMed, Embase, Cochrane Library, Web of Science, Scopus, and Ovid, were searched by the deadline of August 18, 2020. A meta-analysis was conducted on the collected data by means of a random-effects model. The quality of each included article was assessed according to the Newcastle-Ottawa Scale.

RESULTS

Out of 1,819 references, 6 articles and 1 conference abstract were included. Sepsis patients with a loss of muscle mass or sarcopenia had higher mortality (risk ratio [RR]: 1.94, 95% confidence intervals [CI]: 1.59-2.37; I-squared = 18.7%, p < 0.001). The RR of mortality within 30 days (RR: 2.31, 95% CI: 1.78-2.99, p < 0.001) was higher than that of mortality over 30 days. Loss of psoas muscle mass, as evaluated by CT, showed the highest RR of sepsis mortality. In addition, based on data on overall survival retrieved from 4 trials, the pooled hazard ratio (HR) for patients with a loss of muscle mass or sarcopenia was 3.04. Subgroup analysis showed that survival time was the main source of heterogeneity for the overall HR. Furthermore, the scanning areas of muscle mass in survival patients were 0.33 cm2/m2 higher than those measured in deceased patients.

CONCLUSION

A loss of muscle mass, as evaluated by CT scan, was associated with a poor outcome in sepsis.

Association Between Sarcopenia and Survival of Patients with Organ-Confined Renal Cell Carcinoma after Radical Nephrectomy

BACKGROUND

We aimed to describe the effect of preoperative sarcopenia on oncologic outcomes of organ-confined renal cell carcinoma (RCC) after radical nephrectomy.

PATIENTS AND METHODS

A total of 632 patients with pT1-2 RCC who underwent radical nephrectomy between 2004 and 2014 were retrospectively analyzed. From preoperative computerized tomography (CT) scans, skeletal muscle index (SMI) was measured and gender-specific cutoff values at third lumbar vertebra of 52.4 cm²/m² for men and 38.5 cm²/m² for women were used to define sarcopenia. Survivals were compared and associations with sarcopenia were analyzed using Kaplan-Meier log rank tests and Cox proportional hazard regression models. Median follow-up was 83 months.

RESULTS

Of 632 patients, 268 (42.4%) were classified as sarcopenic. The sarcopenic group was more advanced in age (57 versus 53 years) and more predominantly male (71.3% versus 59.9%). Sarcopenic patients had lower body mass index (BMI, 23.0 versus 25.9 kg/m²), but there was no difference in tumor size, stage, or nuclear grade. Sarcopenia was associated with poorer overall survival (OS) and cancer-specific survival (CSS; OS 94.0% versus 82.1%; p < 0.001 and CSS 97.5% versus 91.8%; p < 0.001). On multivariate analysis, sarcopenia was an independent risk factor for all-cause mortality [hazard ratio (HR) 2.58; 95% CI 1.02-6.54] and cancer-specific mortality (HR 3.07; 95% CI 1.38-6.83).

CONCLUSIONS

Sarcopenia at diagnosis was an independent risk factor for all-cause and cancer-specific mortality after radical nephrectomy for pT1-2 RCC. These findings underscore the importance of assessing presence of sarcopenia for risk stratification even among surgical candidates.

Low skeletal muscle mass by computerized tomography is associated with increased mortality risk in end-stage kidney disease patients on hemodialysis

BACKGROUND AND AIMS

Skeletal muscle (SM) area, as measured by abdominal CT at the level of the third lumbar vertebra (L3), has been proposed as a proxy of whole body muscle mass. However, population-specific reference values are lacking. In the present study we aimed at: (1) detecting low SM area on abdominal CT images in patients on hemodialysis by applying cut-offs derived from a group of healthy subjects, and (2) estimating the independent risk of all-cause mortality associated with low SM area.

METHODS

We retrospectively enrolled 212 adult patients on hemodialysis, undergoing abdominal CT scan (study group), and 87 healthy kidney donors (reference group). We obtained the gender-specific 5th percentile values of the abdominal SM area distribution from both the whole control group and the subgroup of younger (29-60 years) subjects, which we used as reference cut-offs. Then we applied those cut-offs in the study group to identify patients with low SM area. We used survival and Cox regression analysis to evaluate the risk of all-cause mortality associated with low abdominal SM area.

RESULTS

In the fully adjusted Cox regression analysis, the patients with low abdominal SM area had a higher risk of death than the patients with values above the reference cut-off derived in the subgroup of younger controls (adjHR = 1.79 (1.21; 2.67), P = 0.004).

CONCLUSIONS

Abdominal CT imaging can be used to detect low abdominal SM area in patients on hemodialysis by applying cut-offs derived from healthy subjects sharing a similar ethnic background. Low SM area as assessed by CT is independently associated with all-cause mortality in ESKD patients on hemodialysis.

Several anthropometric measurements and cancer mortality: predictor screening, threshold determination, and joint analysis in a multicenter cohort of 12138 adults

BACKGROUND

Anthropometric measurements (AMs) are cost-effective surrogates for evaluating body size. This study aimed to identify the optimal prognostic AMs, their thresholds, and their joint associations with cancer mortality.

METHODS

We performed an observational cohort study including 12138 patients with cancer at five institutions in China. Information on demographics, disease, nutritional status, and AMs, including the body mass index, mid-arm muscle circumference, mid-arm circumference, handgrip strength, calf circumference (CC), and triceps-skinfold thickness (TSF), was collected and screened as mortality predictors. The optimal stratification was used to determine the thresholds to categorize those prognostic AMs, and their associations with mortality were estimated independently and jointly by calculating multivariable-adjusted hazard ratios (HRs).

RESULTS

The study included 5744 females and 6394 males with a mean age of 56.9 years. The CC and TSF were identified as better mortality predictors than other AMs. The optimal thresholds were women 30 cm and men 32.8 cm for the CC, and women 21.8 mm and men 13.6 mm for the TSF. Patients in the low CC or low TSF group had a 13% (HR = 1.13, 95% CI = 1.03-1.23) and 22% (HR = 1.22, 95% CI = 1.12-1.32) greater mortality risk compared with their normal CC/TSF counterparties, respectively. Concurrent low CC and low TSF showed potential joint effect on mortality risk (HR = 1.39, 95% CI = 1.25-1.55).

CONCLUSIONS

These findings support the importance of assessing the CC and TSF simultaneously in hospitalized cancer patients to guide interventions to optimize their long-term outcomes.

Relationship Between Skeletal Muscle Area and Density and Clinical Outcome in Adults Receiving Venovenous Extracorporeal Membrane Oxygenation

OBJECTIVES

To investigate the prevalence of low skeletal muscle index (area normalized for height) and density, their trajectory of change, and to determine associations with clinical outcome in adults with severe respiratory failure requiring venovenous extracorporeal membrane oxygenation.

DESIGN

Prospective observational study.

PATIENTS

Adults receiving venovenous extracorporeal membrane oxygenation for a minimum of 72 hours and a maximum of 6 months between September 2010 and June 2017, who had a CT scan which included the third lumbar vertebra.

INTERVENTION

None.

MEASUREMENTS AND MAIN RESULTS

Skeletal muscle index and density was determined using Slice-O-Matic V5.0 (TomoVision, Montreal, QC, Canada). Low skeletal muscle index and density were defined using published criteria. Regression models were used to assess for associations between muscle index and density and clinical outcome. Two-hundred fifteen patients, median (interquartile range) age 46 years (35.0-57.0 yr) were included. Forty-five patients (21.1%) had low skeletal muscle index, and 48 (22.3%) had low skeletal muscle density on commencement of venovenous extracorporeal membrane oxygenation. Low skeletal muscle index was more prevalent in males (28.8% vs 11.6%; χ2 = 9.4; p = 0.002) and was associated with a longer duration of venovenous extracorporeal membrane oxygenation (B = 5.0; 95% CI, 0.2-9.9; p = 0.042). Higher skeletal muscle density was independently associated with ICU survival (odds ratio 1.6 per 10 Hounsfield units; 95% CI, 1.1-2.5; p = 0.025). No relationship was observed between skeletal muscle index nor density and physical function. Adequacy of energy and protein did not influence change in skeletal muscle index or density.

CONCLUSIONS

Low skeletal muscle index at the commencement of venovenous extracorporeal membrane oxygenation was associated with a longer duration of venovenous extracorporeal membrane oxygenation, whereas preserved skeletal muscle density was associated with improved survival.

Body Composition, Inflammation, and 5-Year Outcomes in Colon Cancer

IMPORTANCE

Obesity, particularly visceral obesity and sarcopenia, are poor prognostic indicators in colon cancer.

OBJECTIVES

To explore the association between body composition profiles and 5-year colon cancer outcomes and delineate the associated underlying inflammatory processes.

DESIGN, SETTING, AND PARTICIPANTS

This multicenter translational cohort study included patients with nonmetastatic colon cancer who did not have underlying chronic inflammatory disorders and were not receiving anti-inflammatory drugs referred to tertiary cancer centers from 2009 to 2015. Preoperative acute phase proteins (white cell count, C-reactive protein, and albumin), cytokines (interleukin [IL]-1b, IL-2, IL-6, IL-10, interferon γ, and tumor necrosis factor α), vascular endothelial growth factor (VEGF), and cell surface receptor expression levels (CD11b and CD14) were measured. All patients underwent follow-up for at least 5 years. Data were analyzed in December 2020.

EXPOSURE

Nonmetastatic colon cancer.

MAIN OUTCOMES AND MEASURES

The associations of body composition profiles with 5-year cancer recurrence and disease-specific mortality were analyzed using Mantel Cox log-rank test and Kaplan-Meier curves.

RESULTS

A total of 28 patients were included (median [interquartile range] age, 67 [58-72] years; 22 [78.6%] men). Low skeletal muscle area (SMA) and high visceral to total fat ratio were associated with poor clinical and oncological outcomes, including increased 5-year recurrence (low SMA: hazard ratio [HR], 2.30 [95% CI, 1.41-2.89]; P = .04; high visceral to total fat ratio: HR, 5.78 [95% CI, 3.66-7.95]; P = .02). High visceral to total fat ratio was associated with increased 5-year disease-specific mortality (HR, 5.92 [95% CI, 4.04-8.00]; P = .02). Patients with low SMA who developed a cancer recurrence, compared with those who did not, had higher C-reactive protein (mean [SD], 31.24 [6.95] mg/dL vs 8.11 [0.58] mg/dL; P = .003), IL-6 (mean [SD], 1.93 [1.16] ng/mL vs 0.88 [0.14] ng/mL; P = .004), VEGF (mean [SD], 310.03 [122.66] ng/mL vs 176.12 [22.94] ng/mL; P = .007), and CD14 (mean [SD], 521.23 [302.02] ng/mL vs 322.07 [98.35] ng/mL; P = .03) expression and lower albumin (mean [SD], 3.8 [0.6] g/dL vs 43.50 [3.69] g/dL; P = .01), IL-2 (mean [SD], 0.45 [0.25] ng/mL vs 0.94 [0.43] ng/mL; P < .001), IL-10 (mean [SD], 8.15 [1.09] ng/mL vs 16.32 [4.43] ng/mL; P = .004), and interferon γ (mean [SD], 2.61 [1.36] ng/mL vs 14.87 [3.43] ng/mL; P = .02) levels. Patients with high visceral to total fat ratio who developed recurrence had higher levels of IL-6 (mean [SD], 5.26 [7.05] ng/mL vs 2.76 [3.11] ng/mL; P = .03) and tumor necrosis factor α (mean [SD], 5.74 [4.53] ng/mL vs 4.50 [1.99] ng/mL; P = .03).

CONCLUSIONS AND RELEVANCE

These findings suggest that low SMA and high visceral to total fat ratio were associated with worse colon cancer outcomes and with increased expression of proinflammatory cytokines and VEGF and inhibition of anti-inflammatory cytokines.

Impact of sarcopenia in advanced and metastatic soft tissue sarcoma

Introduction

Advanced or metastatic soft tissue sarcoma (a/mSTS) is associated with a dismal prognosis. Patient counseling on treatment aggressiveness is pivotal to avoid over- or undertreatment. Recently, evaluation of body composition markers like the skeletal muscle index (SMI) became focus of interest in a variety of cancers. This study focuses on the prognostic impact of SMI in a/mSTS, retrospectively.

Methods

181 a/mSTS patients were identified, 89 were eligible due to prespecified criteria for SMI assessment. Baseline CT-Scans were analyzed using an institutional software solution. Sarcopenia defining cut-off values for the SMI were established by optimal fitting method. Primary end point was overall survival (OS) and secondary endpoints were progression free survival (PFS), disease control rate (DCR), overall response rate (ORR). Descriptive statistics as well as Kaplan Meier- and Cox regression analyses were administered.

Results

28/89 a/mSTS patients showed sarcopenia. Sarcopenic patients were significantly older, generally tended to receive less multimodal therapies (62 vs. 57 years, P = 0.025; respectively median 2.5 vs. 4, P = 0.132) and showed a significantly lower median OS (4 months [95%CI 1.9–6.0] vs. 16 months [95%CI 8.8–23.2], Log-rank P = 0.002). Sarcopenia was identified as independent prognostic parameter of impaired OS (HR 2.40 [95%-CI 1.4–4.0], P < 0.001). Moreover, DCR of first palliative medical treatment was superior in non-sarcopenic patients (49.2% vs. 25%, P = 0.032).

Conclusion

This study identifies sarcopenia as a prognostic parameter in a/mSTS. Further on, the data suggest that sarcopenia shows a trend of being associated with first line therapy response. SMI is a promising prognostic parameter, which needs further validation.

Weight Loss Strategies and the Risk of Skeletal Muscle Mass Loss

With energy intake restriction and exercise remaining the key diet and lifestyle approaches to weight loss, this is not without potential negative implications for body composition, metabolic health, and quality and quantity of life. Ideally, weight loss should be derived almost exclusively from the fat mass compartment as this is the main driver of metabolic disease, however, several studies have shown that there is an accompanying loss of tissue from the fat-free compartment, especially skeletal muscle. Population groups including post-menopausal women, the elderly, those with metabolic disease and athletes may be particularly at risk of skeletal muscle loss when following a weight management programme. Research studies that have addressed this issue across a range of population groups are reviewed with a focus upon the contribution of resistance and endurance forms of exercise and a higher intake dietary protein above the current guideline of 0.8 g/kg body weight/day. While findings can be contradictory, overall, the consensus appears that fat-free and skeletal muscle masses can be preserved, albeit to varying degrees by including both forms of exercise (but especially resistance forms) in the weight management intervention. Equally, higher intakes of protein can protect loss of these body compartments, acting either separately or synergistically with exercise. Elderly individuals in particular may benefit most from this approach. Thus, the evidence supports the recommendations for intakes of protein above the current guidelines of 0.8 g/kg body weight/d for the healthy elderly population to also be incorporated into the dietary prescription for weight management in this age group.

Reference Data and T-Scores of Lumbar Skeletal Muscle Area and Its Skeletal Muscle Indices Measured by CT Scan in a Healthy Korean Population

BACKGROUND

Although computed tomography (CT) is considered the gold standard for investigating skeletal muscles, diagnostic cutoff points for sarcopenia have not been established. We therefore suggested clinically relevant diagnostic cutoff points for sarcopenia based on reference values of skeletal muscle area (SMA) measured by CT scan in a large-sized healthy Asian population.

METHODS

This cross-sectional analysis included 11,845 subjects (7,314 men, 4,531 women) who underwent abdominal CT scans in South Korea. SMA including all muscles on the selected axial images of the L3 lumbar vertebrae level was demarcated using predetermined thresholds (-29 to +150 Hounsfield units). SMA indices (height-, weight-, and body mass index [BMI]-adjusted) were calculated.

RESULTS

When T-score < -2.0 was used as the cutoff for defining sarcopenia, the sex-specific cutoff points of SMA, SMA/height2, SMA/weight, and SMA/BMI were 119.3 and 74.2 cm2, 39.8 and 28.4 cm2/m2, 1.65 and 1.38 cm2/kg, and 4.97 and 3.46 in men and women, respectively. In both sexes, the SMA/BMI values peaked in the 20s and decreased gradually. The SMA/BMI yielded the highest diagnostic rate of sarcopenia (4.2% in men, 8.7% in women), while SMA/height2 provided the lowest yield (2.8% in men, 1.0% in women).

CONCLUSIONS

This is the first study to report the reference values of SMA and skeletal muscle indices (SMIs) measured on CT scans and to suggest cutoff points for diagnosis of sarcopenia based on T-score in Asian subjects. BMI-adjusted index (SMA/BMI) was the best index of CT-measured SMA to reflect the age-related muscle changes and to maximize the diagnostic yield for sarcopenia.

Thickness of rectus abdominis measured by ultrasound in critically ill patients after abdominal surgery: A retrospective cohort study

BACKGROUND

Early identification of patients at high risk of prolonged mechanical ventilation is important in critical care. Sarcopenia, the loss of muscle mass and function, has been reported to be associated with extended mechanical ventilation and prolonged ICU stay. Although ultrasound is noninvasive and widely used in critical care, there is no standard method of using it to assess sarcopenia.

OBJECTIVES

The study aims to investigate the relationship between outcomes of critically ill patients and the ratio of BMI to the thickness of rectus abdominis measured by a standardised ultrasound examination.

DESIGN

A retrospective cohort study.

SETTING

Surgical ICU of a tertiary referral hospital, from October 2017 to June 2018. The thickness of rectus abdominis (RA) was measured while performing extended focused assessment sonography for trauma. BMI was divided by the thickness of rectus abdominis over the upper abdomen to derive the BMI-RA thickness ratio.

PATIENTS

Sixteen male and 11 female patients admitted to ICU after major abdominal surgery.

MAIN OUTCOME MEASURES

The primary outcome was in-hospital mortality, and the secondary outcomes were durations of mechanical ventilation, ICU stay and hospital stay. The disease severity, serum albumin level and BMI-RA thickness ratio were also analysed.

RESULTS

Ultrasound measurement was easy to perform without adverse effects. The BMI-RA thickness ratio was significantly higher in nonsurvivors and was associated with ICU stay, hospital stay and duration of mechanical ventilation. Multivariable logistic regression showed that the BMI-RA thickness ratio was a predictor of in-hospital mortality.

CONCLUSION

The BMI-RA thickness ratio is related to the outcomes of patients transferred to ICU after major abdominal surgery. Measuring the thickness of rectus abdominis by ultrasound is well tolerated and easy to perform in surgical ICU. Larger prospective studies are required to confirm current findings.

AWGS2019 vs EWGSOP2 for diagnosing sarcopenia to predict long-term prognosis in Chinese patients with gastric cancer after radical gastrectomy

BACKGROUND

Sarcopenia is a nutrition-related disease and has a profound effect on the long-term overall survival (OS) of patients with gastric cancer. Its diagnostic criterion is critical to clinical diagnosis and treatment. However, previous research reported widely differing sarcopenia prevalence due to different criteria. AWGS2019 and EWGSOP2 are the two latest and widely adopted criteria.

AIM

To compare the effects of AWGS2019 and EWGSOP2 on the long-term OS of Chinese gastric cancer patient after radical gastrectomy.

METHODS

An observational study was conducted from July 2014 to January 2017, which included 648 consecutive gastric cancer patients who underwent radical gastrectomy. The sarcopenia elements (skeletal muscle index, handgrip strength, and gait speed) were measured within 1 mo or 7 d before surgery. The patients were followed at fixed intervals to gain the outcomes. Multivariate Cox regression analysis was performed to determine the association between sarcopenia and the long-term OS of these patients according to the two criteria separately. The predictive performance of the models with AWGS2019 and EWGSOP2 were evaluated by the concordance index (C-index) and area under the time-dependent receiver operating characteristic curve (AUC). The Akaike information criterion (AIC) was applied to compare model fits.

RESULTS

The prevalence of sarcopenia was 20.5% and 11.3% according to AWGS2019 and EWGSOP2, respectively. Sarcopenia was an independent risk factor for the long-term OS no matter based on AWGS2019 or EWGSOP2, but AWGS2019-sarcopenia in multivariate model had a higher hazard ratio (HR) [2.150 (1.547-2.988)] than EWGSOP2-sarcopenia [HR 1.599 (1.092-2.339)]. Meanwhile, the model with AWGS2019-sarcopenia [C-index 0.773 (0.742-0.804); AIC 2193.7; time-dependent AUC 0.812 (0.756-0.867) for 1-year OS, 0.815 (0.778-0.852) for 3-year OS, and 0.809 (0.759-0.859) for 5-year OS] had better predictive power and model fits than the model with EWGSOP2-sarcopenia [C-index 0.762 (0.729-0.795); AIC 2215.2; time-dependent AUC 0.797 (0.741-0.854) for 1-year OS, 0.804 (0.767-0.842) for 3-year OS, and 0.799 (0.748-0.850) for 5-year OS].

CONCLUSION

Sarcopenia is an independent risk factor for the long-term OS in Chinese gastric cancer patients undergoing radical gastrectomy. The prediction model with AWGS2019-sarcopenia has better predictive power and model fits than the prediction model with EWGSOP2-sarcopenia. AWGS2019 may be more appropriate for diagnosing sarcopenia in these Chinese patients than EWGSOP2.

Body Composition and Dose-limiting Toxicity in Colorectal Cancer Chemotherapy Treatment; a Systematic Review of the Literature. Could Muscle Mass be the New Body Surface Area in Chemotherapy Dosing?

Chemotherapy dosing is traditionally based on body surface area calculations; however, these calculations ignore separate tissue compartments, such as the lean body mass (LBM), which is considered a big pool of drug distribution. In our era, colorectal cancer patients undergo a plethora of computed tomography scans as part of their diagnosis, staging and monitoring, which could easily be used for body composition analysis and LBM calculation, allowing for personalised chemotherapy dosing. This systematic review aims to evaluate the effect of muscle mass on dose-limiting toxicity (DLT), among different chemotherapy regimens used in colorectal cancer patients. This review was carried out according to the PRISMA guidelines. MEDLINE and EMBASE databases were searched from 1946 to August 2019. The primary search terms were 'sarcopenia', 'myopenia', 'chemotherapy toxicity', 'chemotherapy dosing', 'dose limiting toxicity', 'colorectal cancer', 'primary colorectal cancer' and 'metastatic colorectal cancer'. Outcomes of interest were - DLT and chemotoxicity related to body composition, and chemotherapy dosing on LBM. In total, 363 studies were identified, with 10 studies fulfilling the selection criteria. Seven studies were retrospective and three were prospective. Most studies used the same body composition analysis software but the chemotherapy regimens used varied. Due to marked study heterogeneity, quantitative data synthesis was not possible. Two studies described a toxicity cut-off value for 5-fluorouracil and one for oxaliplatin based on LBM. The rest of the studies showed an association between different body composition metrics and DLTs. Prospective studies are required with a larger colorectal cancer cohort, longitudinal monitoring of body composition changes during treatment, similar body composition analysis techniques, agreed cut-off values and standardised chemotherapy regimens. Incorporation of body composition analysis in the clinical setting will allow early identification of sarcopenic patients, personalised dosing based on their LBM and early optimisation of these patients undergoing chemotherapy.

The Spectrum of Malnutrition/Cachexia/Sarcopenia in Oncology According to Different Cancer Types and Settings: A Narrative Review

Nutritional status in oncological patients may differ according to several modifiable and non-modifiable factors. Knowledge of the epidemiology of malnutrition/cachexia/sarcopenia may help to manage these complications early in the course of treatment, potentially impacting patient quality of life, treatment intensity, and disease outcome. Therefore, this narrative review aimed to critically evaluate the current evidence on the combined impact of tumor- and treatment-related factors on nutritional status and to draw some practical conclusions to support the multidisciplinary management of malnutrition in cancer patients. A comprehensive literature search was performed from January 2010 to December 2020 using different combinations of pertinent keywords and a critical evaluation of retrieved literature papers was conducted. The results show that the prevalence of weight loss and associated symptoms is quite heterogeneous and needs to be assessed with recognized criteria, thus allowing a clear classification and standardization of therapeutic interventions. There is a large range of variability influenced by age and social factors, comorbidities, and setting of cures (community-dwelling versus hospitalized patients). Tumor subsite is one of the major determinants of malnutrition, with pancreatic, esophageal, and other gastroenteric cancers, head and neck, and lung cancers having the highest prevalence. The advanced stage is also linked to a higher risk of developing malnutrition, as an expression of the relationship between tumor burden, inflammatory status, reduced caloric intake, and malabsorption. Finally, treatment type influences the risk of nutritional issues, both for locoregional approaches (surgery and radiotherapy) and for systemic treatment. Interestingly, personalized approaches based on the selection of the most predictive malnutrition definitions for postoperative complications according to cancer type and knowledge of specific nutritional problems associated with some new agents may positively impact disease course. Sharing common knowledge between oncologists and nutritionists may help to better address and treat malnutrition in this population.

Reference Values for Skeletal Muscle Mass at the Third Lumbar Vertebral Level Measured by Computed Tomography in a Healthy Korean Population

BACKGROUND

Sarcopenia is defined as the loss of skeletal muscle mass and is associated with negative clinical outcomes. This study aimed to establish sex-specific cutoff values for the skeletal muscle area (SMA) and skeletal muscle index (SMI) at the third lumbar vertebral (L3) level using computed tomography (CT) imaging to identify sarcopenia in healthy Korean liver donors.

METHODS

This retrospective study included 659 healthy liver donors (408 men and 251 women) aged 20 to 60 years who had undergone abdominal CT examinations between January 2017 and December 2018. Assessment of body composition was performed with an automated segmentation technique using a deep-learning system. Sex-specific SMA and SMI distributions were assessed, and cutoff values for determining sarcopenia were defined as values at either two standard deviations (SDs) below the mean reference value or below the fifth percentile.

RESULTS

Using the SD definition, cutoff values for SMA and SMI were 117.04 cm2 and 39.33 cm2/m2, respectively, in men and 71.39 cm2 and 27.77 cm2/m2, respectively, in women. Using the fifth percentile definition, cutoff values for SMA and SMI were 126.88 cm2 and 40.96 cm2/m2, respectively, in men and 78.85 cm2 and 30.60 cm2/m2, respectively, in women.

CONCLUSION

Our data provide sex-specific cutoff values for the SMA and SMI at the L3 level measured by CT imaging in a healthy Korean population, which may be applicable for identifying sarcopenia in this population.

Comparison of ultrasound speed-of-sound of the lower extremity and lumbar muscle assessed with computed tomography for muscle loss assessment

To compare the speed of propagation of ultrasound (US) waves (SoS) of the lower leg with the clinical reference standard computed tomography (CT) at the level of lumbar vertebra 3 (L3) for muscle loss assessment. Both calf muscles of 50 patients scheduled for an abdominal CT were prospectively examined with ultrasound. A plexiglas-reflector located on the opposite side of the probe with the calf in between was used as a timing reference for SoS (m/s). CT measurements were performed at the level of L3 and included area (cm2) and attenuation (HU) of the psoas muscle, abdominal muscles, subcutaneous fat, visceral fat and abdominal area. Correlations between SoS, body mass index (BMI) and CT were determined using Pearson's correlation coefficient. Based on reported CT sarcopenia threshold values, receiver operating characteristic (ROC) analysis was performed for SoS. Inter-examiner agreement was assessed with the median difference, inter-quartile range (IQR) and intraclass correlation coefficients. SoS of the calf correlated moderately with abdominal muscle attenuation (r = 0.48; P < .001), psoas muscle attenuation (r = 0.40; P < .01), abdominal area (r = -0.44; P < .01) and weakly with subcutaneous fat area (r = -0.37; P < .01). BMI correlated weakly with psoas attenuation (r = -0.28; P < .05) and non-significantly with abdominal muscle attenuation. Normalization with abdominal area resulted in moderate correlations with abdominal muscle area for SoS (r = 0.43; P < .01) and BMI (r = -0.46; P < .001). Based on sarcopenia threshold values for skeletal muscle attenuation (SMRA), area under curve (AUC) for SoS was 0.724. Median difference between both examiners was -3.4 m/s with IQR = 15.1 m/s and intraclass correlation coefficient = 0.794. SoS measurements of the calf are moderately accurate based on CT sarcopenia threshold values, thus showing potential for muscle loss quantification.

Are muscle parameters obtained by computed tomography associated with outcome after esophagectomy for cancer?

BACKGROUND & AIMS

Esophageal cancer patients often suffer from cancer-related malnutrition and, as a result, sarcopenia. Whether sarcopenia worsens the outcome after esophagectomy is unclear. Inconsistent study results are partly caused by varying cut-off values used for defining sarcopenia. To overcome this challenge, a new statistical approach is proposed in this study: analyzing the linear association of computer tomography derived muscle parameters with important clinical short- and long-term outcomes post esophagectomy, regardless of cut-offs.

METHODS

Skeletal muscle index (SMI), quantifying muscle mass, was assessed with computed tomography (CT) in 98 patients undergoing esophagectomy. Muscle radiation attenuation (MRA) was measured to evaluate muscle quality. To evaluate the influence of the SMI and MRA on post-surgery complications, logistic regression models were used. To analyze the relationship of lengths of stay to muscle parameters, the competing risk approach introduced by Fine and Gray was applied. For survival analysis, log-rank test and Cox proportional hazards regression modeling were used.

RESULTS

Neither a relevant association of SMI nor MRA with pneumonia and esophagoenteric leak were observed. Furthermore, no relevant association to lengths of stay in intensive care or hospital were detected. If the SMI increased, the odds for pleural effusion and pleural empyema decreased, but the odds of a pulmonary embolism increased. Univariate, unadjusted long-term survival analysis revealed that lower MRA and lower SMI were associated with shorter survival (P = 0.03). However, if the analysis was adjusted for confounders, e.g., Charlson Comorbidity Index, no relevant association regarding long-term survival was detected.

CONCLUSION

Consequently, poor muscle status, determined by CT imaging, does not justify denying a patient an oncologic resection. The Charlson Comorbidity Index, however, was superior for preoperative risk stratification.

Sarcopenia is associated with blood transfusions in head and neck cancer free flap surgery

OBJECTIVE

To determine if sarcopenia is a predictor of blood transfusion requirements in head and neck cancer free flap reconstruction (HNCFFR).

METHODS

A single-institution, retrospective review was performed of HNCFFR patients with preoperative abdominal imaging from 2014 to 2019. Demographics, comorbidities (modified Charlson Comorbidity Index [mCCI]), skeletal muscle index (cm2/m2), oncologic history, intraoperative data, and 30-day postoperative complications (Clavien-Dindo score [CD]) were collected. Binary logistic regression was performed to determine predictors of transfusion.

RESULTS

Eighty (33.5%), 66 (27.6%), and 110 (46.0%) of n = 239 total patients received an intraoperative, postoperative, or any perioperative blood transfusion, respectively. Sixty-two (25.9%) patients had sarcopenia. Patients receiving intraoperative transfusions had older age (P = .035), more frequent alcoholism (P = .028) and sarcopenia (P < .001), greater mCCI (P < .001), lower preoperative hemoglobin (P < .001), reconstruction with flaps other than forearm (P = .003), and greater operative times (P = .001), intravenous fluids (P < .001), and estimated blood loss (EBL, P < .001). Postoperative transfusions were associated with major complications (CD ≥ 3; P < .001). Multivariate regression determined sarcopenia (P = .023), mCCI (P = .013), preoperative hemoglobin (P = .002), operative time (P = .036), and EBL (P < .001) as independent predictors of intraoperative transfusion requirements. Postoperative transfusions were predicted by preoperative hemoglobin (P = .007), osseous flap (P = .036), and CD ≥ 3 (P < .001). A perioperative transfusion was predicted by sarcopenia (P = .021), preoperative hemoglobin (P < .001), operative time (P = .008), and CD ≥ 3 (P = .018).

CONCLUSION

Sarcopenia is associated with increased blood transfusions in HNCFFR. Patients should be counseled preoperatively on the associated risks, and the increased blood product requirement should be accounted in resource-limited scenarios.

LEVEL OF EVIDENCE

4.

Skeletal muscle fat quantification by dual-energy computed tomography in comparison with 3T MR imaging

Objectives

To quantify the proportion of fat within the skeletal muscle as a measure of muscle quality using dual-energy CT (DECT) and to validate this methodology with MRI.

Methods

Twenty-one patients with abdominal contrast-enhanced DECT scans (100 kV/Sn 150 kV) underwent abdominal 3-T MRI. The fat fraction (DECT-FF), determined by material decomposition, and HU values on virtual non-contrast-enhanced (VNC) DECT images were measured in 126 regions of interest (≥ 6 cm²) within the posterior paraspinal muscle. For validation, the MR-based fat fraction (MR-FF) was assessed by chemical shift relaxometry. Patients were categorized into groups of high or low skeletal muscle mean radiation attenuation (SMRA) and classified as either sarcopenic or non-sarcopenic, according to the skeletal muscle index (SMI) and cut-off values from non-contrast-enhanced single-energy CT. Spearman’s and intraclass correlation, Bland-Altman analysis, and mixed linear models were employed.

Results

The correlation was excellent between DECT-FF and MR-FF (r = 0.91), DECT VNC HU and MR-FF (r = - 0.90), and DECT-FF and DECT VNC HU (r = − 0.98). Intraclass correlation between DECT-FF and MR-FF was good (r = 0.83 [95% CI 0.71–0.90]), with a mean difference of - 0.15% (SD 3.32 [95% CI 6.35 to − 6.66]). Categorization using the SMRA yielded an eightfold difference in DECT VNC HU values between both groups (5 HU [95% CI 23–11], 42 HU [95% CI 33–56], p = 0.05). No significant relationship between DECT-FF and SMI-based classifications was observed.

Conclusions

Fat quantification within the skeletal muscle using DECT is both feasible and reliable. DECT muscle analysis offers a new approach to determine muscle quality, which is important for the diagnosis and therapeutic monitoring of sarcopenia, as a comorbidity associated with poor clinical outcome.

Key Points

• Dual-energy CT (DECT) material decomposition and virtual non-contrast-enhanced DECT HU values assess muscle fat reliably.

• Virtual non-contrast-enhanced dual-energy CT HU values allow to differentiate between high and low native skeletal muscle mean radiation attenuation in contrast-enhanced DECT scans.

• Measuring muscle fat by dual-energy computed tomography is a new approach for the determination of muscle quality, an important parameter for the diagnostic confirmation of sarcopenia as a comorbidity associated with poor clinical outcome.

Assessment of sarcopenia in patients with upper gastrointestinal tumors: Prevalence and agreement between computed tomography and dual-energy x-ray absorptiometry

BACKGROUND & AIMS

Sarcopenia is associated with an increased risk of complications to treatment and lower survival rates in patients with cancer, but there is a lack of agreement on cut-off values and assessment methods. We aimed to investigate the prevalence of sarcopenia assessed by dual-energy x-ray absorptiometry (DXA) and computed tomography (CT) as well as the agreement between the methods for identification of sarcopenia.

METHODS

This cross-sectional study pooled data from two studies including patients scheduled for surgery for gastrointestinal tumors. We assessed sarcopenia using two different cut-off values derived from healthy young adults for DXA and two for CT. Additionally, we used one of the most widely applied cut-off values for CT assessed sarcopenia derived from obese cancer patients. The agreement between DXA and CT was evaluated using Cohen's kappa. The mean difference and range of agreement between DXA and CT for estimating total and appendicular lean soft tissue were assessed using Bland-Altman plots.

RESULTS

In total, 131 patients were included. With DXA the prevalence of sarcopenia was 11.5% and 19.1%. Using CT, the prevalence of sarcopenia was 3.8% and 26.7% using cut-off values from healthy young adults and 64.1% using the widely applied cut-off value. The agreement between DXA and CT in identifying sarcopenia was poor, with Cohen's kappa values ranging from 0.05 to 0.39. The mean difference for estimated total lean soft tissue was 1.4 kg, with 95% limits of agreement from -8.6 to 11.5 kg. For appendicular lean soft tissue, the ratio between DXA and CT was 1.15, with 95% limits of agreement from 0.92 to 1.44.

CONCLUSIONS

The prevalence of sarcopenia defined using DXA and CT varied substantially, and the agreement between the two modalities is poor.

Identifying Patients with Osteoarthritis at Risk of Sarcopenia using the SARC-F

Background

Sarcopenia is an important modifiable risk factor in patients being considered for elective knee or hip replacement as it may be associated with a higher risk of post-operative joint replacement complications. Our objectives are to determine the prevalence of patients with osteoarthritis at risk of sarcopenia by using the SARC-F tool, and whether risk of sarcopenia is associated with referral to an orthopaedic surgeon.

Methods

We conducted a retrospective review of patients who were 60 years or older assessed at four Canadian musculoskeletal assessment centres. Patients completed the SARC-F as part of their assessment. Multivariable logistic regression analyses were conducted to determine association between risk of sarcopenia and the odds of referral to an orthopedic surgeon for surgical consultation.

Results

3,697 patients were included and 67.8% (2,508/3,697) were at risk of sarcopenia. Prevalence was highest in those assessed for hip replacement at 72.3% (635/878). Patients at risk of sarcopenia were more likely to be referred to an orthopaedic surgeon (OR 1.299; SD 1.074–1.571).

Conclusions

Patients with osteoarthritis assessed for joint replacement are at high risk of sarcopenia, particularly individuals undergoing potential hip replacement. Patients at risk of sarcopenia are more likely to be referred to orthopaedic surgery for surgical consultation.

The role of sarcopenic obesity in high-grade endometrial cancer

OBJECTIVE

To investigate the relationship between obesity and sarcopenia in relation to overall survival (OS) and disease-specific survival (DSS) in high-grade endometrial cancer patients.

METHODS

We conducted a retrospective study in women diagnosed with high-grade endometrial cancer (EC) between February 2006 and August 2017 in the Royal Cornwall Hospital who had abdominal computerized tomography (CT)-scan as part of routine staging work-up. Sarcopenia was assessed by measuring psoas-, paraspinal- and abdominal wall muscles on CT and defined by skeletal muscle index ≤41 cm² /m² . Sarcopenic obesity was defined as sarcopenia combined with body mass index (BMI) ≥30 kg/m² .

RESULTS

A total of 176 patients with median age of 70 years and median BMI of 29.4 kg/m² were included in the study. The majority of patients (38%) had endometrioid type histology. Sarcopenia was not associated with OS (P = 0.951) or DSS (P = 0.545) However, in multivariate analysis, sarcopenic obesity was associated with reduced OS in endometrioid endometrial cancer (EEC) patients (P = 0.048).

CONCLUSION

Sarcopenic obesity is associated with OS in high-grade EEC patients, while sarcopenia without obesity is not related to OS or DSS in high-grade EC. In non-endometrioid endometrial cancer, there is no association between sarcopenic obesity and survival.

Sarcopenia and Myosteatosis Predict Adverse Outcomes After Emergency Laparotomy: A Multi-Centre Observational Cohort Study

OBJECTIVE

To determine the relationship between body composition (BC), specifically low skeletal muscle mass (sarcopenia) and poor muscle quality (myosteatosis) and outcomes in emergency laparotomy patients.

BACKGROUND

Emergency laparotomy has one of the highest morbidity and mortality rates of all surgical interventions. BC objectively identifies patients at risk of adverse outcomes in elective cancer cohorts, however evidence is lacking in emergency surgery.

METHODS

An observational cohort study of patients undergoing emergency laparotomy at ten English hospitals was performed. BC analyses were performed at the third lumbar vertebrae level using pre-operative CT images to quantify skeletal muscle index (SMI) and skeletal muscle radiation attenuation (SM-RA). Sex-specific SMI and SM-RA were determined, with the lower tertile splits defining sarcopenia (low SMI) and myosteatosis (low SM-RA). Accuracy of mortality risk prediction, incorporating SMI and SM-RA variables into risk models was assessed with regression modelling.

RESULTS

Six hundred and ten patients were included. Sarcopenia and myosteatosis were both associated with increased risk of morbidity (52.1% vs. 45.1%, p = 0.028; 57.5% vs. 42.6%, p = 0.014), 30-day (9.5% vs. 3.6%, p = 0.010; 14.9% vs. 3.4%, p < 0.001), and 1-year mortality (27.4% vs. 11.5%, p < 0.001; 29.7% vs.12.5%, p < 0.001). Risk-adjusted 30-day mortality was significantly increased by sarcopenia (OR 2.56 (95%CI 1.12-5.84), p = 0.026) and myosteatosis (OR 4.26 (2.01-9.06), p < 0.001), similarly at 1-year (OR 2.66 (95%CI 1.57-4.52), p < 0.001; OR 2.08 (95%CI 1.26-3.41), p = 0.004). BC data increased discrimination of an existing mortality risk-prediction model (AUC 0.838, 95%CI 0.835-0.84).

CONCLUSION

Sarcopenia and myosteatosis are associated with increased adverse outcomes in emergency laparotomy patients.

Quantitative assessment of erector spinae muscles and prognosis in elderly patients with pneumonia

Erector spinae muscle (ESM) size has been reported as a predictor of prognosis in patients with some respiratory diseases. This study aimed to assess the association of ESM size on all-cause in-hospital mortality among elderly patients with pneumonia. We retrospectively included patients (age: ≥ 65 years) admitted to hospital from January 2015 to December 2017 for community-acquired pneumonia who underwent chest computed tomography (CT) on admission. The cross-sectional area of the ESM (ESMcsa) was measured on a single-slice CT image at the end of the 12th thoracic vertebra and adjusted by body surface area (BSA). Cox proportional hazards regression models were used to assess the influence of ESMcsa/BSA on in-hospital mortality. Among 736 patients who were admitted for pneumonia, 702 patients (95%) underwent chest CT. Of those, 689 patients (98%) for whom height and weight were measured to calculate BSA were included in this study. Patients in the non-survivor group were significantly older, had a greater frequency of respiratory failure, loss of consciousness, lower body mass index, hemoglobin, albumin, and ESMcsa/BSA. Multivariate analysis showed that a lower ESMcsa/BSA independently predicted in-hospital mortality after adjusting for these variables. In elderly patients with pneumonia, quantification of ESMcsa/BSA may be associated with in-hospital mortality.

Trunk Skeletal Muscle Changes on CT with Long-Duration Spaceflight

Astronauts exposed to microgravity for extended time are susceptible to trunk muscle atrophy, which may compromise strength and function on mission and after return. This study investigates changes in trunk skeletal muscle size and composition using computed tomography (CT) and dual-energy X-ray absorptiometry (DXA) among 16 crewmembers (1 female, 15 male) on 4-6 month missions. Muscle cross-sectional area and muscle attenuation were measured using abdominal CT scans at pre-flight, post-flight return, 1 year post-flight, and 2-4 years post-flight. Longitudinal muscle changes were analyzed using mixed models. In six crewmembers, CT and DXA data were used to calculate subject height-normalized skeletal muscle indices. Changes in these indices were analyzed using paired t-tests and compared by imaging modality using Pearson correlations. Trunk muscle area decreased at post-flight return (- 4.7 ± 1.1%, p < 0.001) and recovered to pre-flight values at 1-4 years post-flight. Muscle attenuation changes were not significant. Skeletal muscle index from CT decreased (- 5.2 ± 1.0%, p = 0.004) while appendicular skeletal muscle index from DXA did not change significantly. In summary, trunk muscle atrophies with long-duration microgravity exposure but recovers to pre-flight values within 1-4 years. The CT measures highlight size decreases not detected with DXA, emphasizing the importance of advanced imaging modalities in assessing muscle health with spaceflight.

Cut-off values of skeletal muscle index and psoas muscle index at L3 vertebra level by computerized tomography to assess low muscle mass

BACKGROUND & AIMS

Computerized tomography (CT) is considered the gold standard for the evaluation of total skeletal muscle quantity. Skeletal muscle assessments at the L3 vertebra level revealed significantly correlated with total body muscle measurements. Clinicians need cut-offs to evaluate low muscle mass in various patients who already had CT imaging without any additional cost. This assessment is important to help the physicians to stratify the patients for mortality and other complications. It may also enable the diagnosis of malnutrition by the GLIM criteria. Few studies reported cut-offs in different populations. We aimed to provide cut-off values for total skeletal muscle index (SMI) and psoas muscle mass index (PMI) at the L3 vertebra level in the Turkish population.

METHODS

We assessed the preoperative plain CT images of living adult liver donors who were admitted to a single transplantation center between June 2010 and April 2018. We derived cut-off values with two alternative methods, the 5th percentile value or mean minus two standard deviations and from two groups of study participants, i.e. the total study population and the younger subgroup aged between 18 and 40.

RESULTS

The study population involved 601 subjects with a mean age of 32.5 ± 9 (range: 18-59 years) and 326 (54.2%) was male. The younger subgroup was composed of 482 individuals with a mean age of 28.8 ± 5.9 and 55.6% male. In patients aged between 18 and 40, PMI and SMI cut-offs by using the 5th percentile were 5.40 cm²/m², 41.42 cm²/m² for males; and 3.56 cm²/m², 30.70 cm²/m² for females; respectively. The cut-offs of PMI and SMI by using mean minus two standard deviations were 4.62 cm²/m², 38.67 cm²/m² for males; and 2.66 cm²/m², 27.8 cm²/m² for females; respectively. These cut-offs were comparable to the other populations.

CONCLUSIONS

Our study provided cut-offs to be used in CT images for PMI and SMI. There is a need for further longitudinal studies to verify whether these cut-offs are successful in predicting mortality or other adverse outcomes associated with low muscle mass.

Optimal body size adjustment of L3 CT skeletal muscle area for sarcopenia assessment

Measurements of skeletal muscle cross-sectional area (SMA) at the level of the third lumbar (L3) vertebra derived from clinical computed tomography (CT) scans are commonly used in assessments of sarcopenia, the loss of skeletal muscle mass and function associated with aging. As SMA is correlated with height and Body Mass Index (BMI), body size adjustment is necessary to fairly assess sarcopenic low muscle mass in individuals of different height and BMI. The skeletal muscle index, a widely used measure, adjusts for height as [Formula: see text] but uses no BMI adjustment. There is no agreed upon standard for body size adjustment. We extracted L3 SMA using non-contrast-enhanced CT scans from healthy adults, split into 'Under-40' and 'Over-40' cohorts. Sex-specific allometric analysis showed that height to the power of one was the optimal integer coefficient for height adjusted SMA in both males and females. We computed two height-adjusted measures [Formula: see text] and [Formula: see text], comparing their Pearson correlations versus age, height, weight, and BMI separately by sex and cohort. Finally, in the 'Under-40' cohort, we used linear regression to convert each height-adjusted measure into a z-score ([Formula: see text], [Formula: see text]) adjusted for BMI. [Formula: see text] was less correlated with height in both males and females ([Formula: see text], [Formula: see text] and [Formula: see text], [Formula: see text]) than [Formula: see text] ([Formula: see text] and [Formula: see text], [Formula: see text]). [Formula: see text] was uncorrelated with BMI and weight, and minimally correlated with height in males and females ([Formula: see text], [Formula: see text] and [Formula: see text], [Formula: see text]). The final [Formula: see text] equation was: [Formula: see text], where [Formula: see text], [Formula: see text], [Formula: see text], and sex = 1 if male, 0 if female. We propose [Formula: see text] for optimal height adjustment and the [Formula: see text] score for optimal height and BMI adjustment. By minimizing correlations with height and BMI, the [Formula: see text] score produces unbiased assessments of relative L3 skeletal muscle area across the full range of body sizes.

Association Between Muscle Quality Measured by Abdominal Computed Tomography and Subclinical Coronary Atherosclerosis

OBJECTIVE

Low muscle mass was known to be associated with cardiovascular diseases. However, only few studies investigated the association between muscle quality and subclinical coronary atherosclerosis. Thus, we evaluated whether muscle quality measured by abdominal computed tomography is associated with the risk of coronary artery calcification. Approach and Results: We conducted a cross-sectional study on 4068 subjects without cardiovascular disease who underwent abdominal and coronary computed tomography between 2012 and 2013 during health examinations. The cross-sectional area of the skeletal muscle was measured at the L3 level (total abdominal muscle area) and segmented into normal attenuation muscle area, low attenuation muscle area, and intramuscular adipose tissue. We calculated the normal attenuation muscle area/total abdominal muscle area index, of which a higher value reflected a higher proportion of good quality muscle (normal attenuation muscle area) and a lower proportion of myosteatosis (low attenuation muscle area and intramuscular adipose tissue). In women, as the normal attenuation muscle area/total abdominal muscle area quartiles increased, the odds ratios (95% CIs) for significant coronary artery calcification (>100) consistently decreased (0.44 [0.24-0.80], 0.39 [0.19-0.81], 0.34 [0.12-0.98]; P=0.003) after adjusting for cardiovascular risk factors including visceral fat area and insulin resistance. In men, the odds ratios in the Q2 group were significantly lower than those in the Q1, but the association was attenuated in Q3-4 after adjustment.

CONCLUSIONS

A higher proportion of good quality muscle was strongly associated with a lower prevalence of significant coronary artery calcification after adjustment, especially in women. Poor skeletal muscle quality may be an important risk factor for subclinical coronary atherosclerosis.

Malnutrition and non-compliance to nutritional recommendations in patients with cirrhosis are associated with a lower survival

BACKGROUND

Malnutrition is frequently encountered in patients with cirrhosis and appears to significantly impact their prognosis. While evaluating the burden of malnutrition in cirrhosis is gathering momentum, as suggested by multiple recently published reports, there is still a persistent scarcity of solid data in the field, especially with regards to the role of nutritional interventions.

AIM

To assess the prevalence of malnutrition in patients with advanced cirrhosis and to evaluate its impact on survival.

METHODS

One hundred and one consecutive patients with advanced cirrhosis were screened for malnutrition using the Subjective Global Assessment (SGA) criteria and the mid-arm circumference (MAC). Malnutrition was defined as SGA class B and C and MAC < 10^th percentile. All patients were interviewed regarding their food intake using an adapted questionnaire. Subsequently, total energy intake was calculated and further subdivided in main nutrients. The data were then compared to the available recommendations at the time of analysis to assess adherence.

RESULTS

54/79 patients (68.4%) in the decompensated group had malnutrition, while only 3/22 patients (13.6%) were malnourished in the compensated group. After a median follow-up time of 27 mo (0-53), the overall mortality was 70%. Survival was significantly lower among patients with malnutrition. The mortality rates were 50% at 1 year and 63% at 2 years for the patients with malnutrition, compared to 21% at 1 year and 30% at 2 years for patients without malnutrition (P = 0.01). On multivariate analysis, the factors independently associated with mortality were age, creatinine level and adherence to the protein intake recommendations. The mortality was lower in patients with the appropriate protein intake: 8% at 1 year and 28% at 2 years in the adherent group, compared to 47% at 1 year and 56% at 2 years in the non-adherent group.

CONCLUSION

The prevalence of malnutrition is high among patients with advanced cirrhosis and might be related in part to a low adherence to nutritional recommendations, especially with regards to protein intake.

Impact of sarcopenia on glycemic control and atherosclerosis in Japanese patients with type 2 diabetes: Cross-sectional study using outpatient clinical data

AIM

This study examined the association among sarcopenia and various surrogate markers of atherosclerosis in Japanese patients with type 2 diabetes (T2D).

METHODS

Patients with T2D who visited the outpatient clinic comprised the study's participants. Handgrip strength (Grip), usual gait speed (GS) and skeletal muscle index, in addition to glycated hemoglobin, ankle-brachial index (ABI) and intima-media thickening (IMT), were measured in 1030 patients for the diagnosis of sarcopenia. From these results were obtained three categorical data (without sarcopenia [NS], sarcopenia with two factors [Sw2], sarcopenia with three factors [Sw3]), and continuous data for atherosclerosis.

RESULTS

Glycated hemoglobin was significantly high among patients in the Sw3 category, as well as among all patients with sarcopenia, compared with those in the NS group, after adjustment was made for age, gender, duration of diabetes, and medications for hypertension and dyslipidemia. ABI was significantly low among the Sw2 and Sw3 patients, as well as among all patients with sarcopenia, but mean and maximum IMT were not when compared with the NS category of patients after the adjustment described above. However, skeletal muscle index, Grip and GS were positively associated with ABI after the adjustment. Grip and GS were negatively associated with maximum IMT after the adjustment.

CONCLUSIONS

These results imply that measurements to diagnose sarcopenia could play an important role for early detection of preclinical atherosclerosis, specifically peripheral artery disease, among Japanese patients with T2D. Geriatr Gerontol Int 2020; 20: 1196-1201.

Evaluation of Sarcopenia with F-18 FDG PET/CT and relation with disease outcomes in patients with multiple myeloma

INTRODUCTION

Multiple myeloma (MM) is a potentially incurable haematological malignancy with devastating manifestations including lytic bone lesions leading to fractures and renal insufficiency. As a disease of patients with a mean age of 66 years, both the disease and the continuous efforts of treatments lead to frailty and devastation. From this stand point, we aimed to evaluate the development of muscle loss in MM patients and also with a new method of sarcopenia evaluation, F-18 FDG PET/CT. While used for bone disease routinely, this method brings a fresh perspective of metabolic quantitation of alteration of muscles which may be regarded as muscle quality.

MATERIALS AND METHODS

Data and images of 105 patients with MM both before and after treatment were evaluated in a retrospective manner.

RESULTS

Both female and male patients were observed to be effected after MM treatment in terms of lumbar and femoral muscle evaluations with CT. Metabolic evaluations confirmed a loss of quality in muscles in terms of metabolic volume and total lesion glycolysis.

CONCLUSION

Sarcopenia should be evaluated in every patient and regarded as a treatment target. FDG PET/CT is an easy and handy tool to assess muscle mass and quality as well as MM disease status.

Formula for the Cross-Sectional Area of the Muscles of the Third Lumbar Vertebra Level from the Twelfth Thoracic Vertebra Level Slice on Computed Tomography

The purpose of this study was to investigate a means by which to reflect muscle mass using chest computed tomography (CT). A cross-sectional study was conducted with patients aged ≥ 65 years having abdominal and chest CT scans. The formula to predict third lumbar vertebra (L3) cross-sectional area (CSA) of the muscles from the erector muscles of the spine at the twelfth thoracic vertebra (Th12) level slice on CT was created using the five-fold cross-validation method. Correlation between predicted L3 CSA and measured L3 CSA of the muscles was assessed by intraclass correlation coefficients (ICC) and correlation coefficients (r) in the data of the development, and predictability was examined with accuracy and F-values in the validation study. The development study included 161 patients. The developed formula was as follows: −1006.38 + 16.29 × age + 1161.80 × sex (if female, 0; if male, 1) + 55.91 × body weight + 2.22 × CSA of the erector muscles at Th12. The formula demonstrated strong concordance and correlation (ICC = 0.849 [0.800–0.887] and r = 0.858 [0.811–0.894]). The validation study included 34 patients. The accuracy and F-value between predicted CSA and measured CSA were high (accuracy = 0.889–0.944, F-value = 0.931–0.968). We developed a formula predicting CSA at L3 using Th12 CT slice. This formula could be used to assess decreased muscle mass even with chest CT alone.

Skeletal Muscle Composition Predicts Outcome in Critically Ill Patients

Supplemental Digital Content is available in the text.

Parameters of patients’ body composition have been suggested as prognostic markers in several clinical conditions including cancer and liver transplantation, but only limited data on its value in critical illness exist to date. In this study, we aimed at evaluating a potential prognostic value of the skeletal muscle mass and skeletal muscle myosteatosis of critically ill patients at admission to the ICU.

Magnetic resonance imaging assessment of body composition parameters in Crohn's disease

BACKGROUND

Body composition, currently evaluated by computed tomography scan, is related to poor evolution and severity of Crohn's disease (CD). Few MRI studies have been performed, yet it is the most commonly used imaging modality for the surveillance of the disease.

AIM

Evaluate the feasibility of MRI body composition measurement and compare the variation according to the activity of the disease.

METHODS

A cohort of 132 consecutive patients was studied. The visceral adiposity index (VAI), subcutaneous adiposity index (SAI) and skeletal muscle index (SMI) were measured. Patients were divided into 2 groups according to disease activity. Sarcopenic status was defined according to the cut off value (SMI < 38.9 cm²/m² in women and < 54.4 cm²/m² in men).

RESULTS

MRI measurements of body composition parameters were feasible and reproducible. After adjustment, sarcopenia was more common (2.07 [1.02; 4.27], p = 0.046), and the SMI (-4.90 [-9.36; -0.431], p = 0.032) was lower in active disease. The SAI was lower (-14.7 [-29.8; 0.258], p = 0.054) in active disease. The VAI tended to be higher with active disease (3.91 [-3.50; 11.9], p = 0.34), and the VAI/SAI+VAI ratio was higher (9.40 [4.72; 14.1], p<0.001).

CONCLUSION

Assessment of body composition is feasible and reproducible in routine MR and parameters are related to disease activity.

The clinical relevance and mechanism of skeletal muscle wasting

Skeletal muscle wasting occurs in both chronic and acute diseases. Increasing evidence has shown this debilitating process is associated with short- and long-term outcomes in critical, cancer and surgical patients. Both muscle quantity and quality, as reflected by the area and density of a given range of attenuation in CT scan, impact the patient prognosis. In addition, ultrasound and bioelectrical impedance analysis (BIA) are also widely used in the assessment of body composition due to their bedside viability and no radioactivity. Mechanism researches have revealed complicated pathways are involved in muscle wasting, which include altered IGF1-Akt-FoxO signaling, elevated levels of myostatin and activin A, activation of NF-κB pathway and glucocorticoid effects. Particularly, central nervous system (CNS) has been proven to participate in regulating muscle wasting in various conditions, such as infection and tumor. Several promising therapeutic agents have been under developing in the treatment of muscle atrophy, such as myostatin antagonist, ghrelin analog, non-steroidal selective androgen receptor modulators (SARMs). Notably, nutritional therapy is still the fundamental support in combating muscle wasting. However, the optimizing and tailored nutrition regimen relies on accurate metabolism measurement and large clinical trials in the future. Here, we will discuss the current understanding of muscle wasting and potential treatment in clinical practice.

Percentiles for body composition parameters based on computed tomography in patients with endometrial cancer

OBJECTIVES

The aim of this study was to provide the percentiles of distribution of body composition parameters according to cancer staging and body mass index (BMI) stratum, as well as to identify the contribution of age, BMI, and cancer staging in the variation of the different parameters of body composition in a population of patients with endometrial cancer.

METHODS

We enrolled 545 patients who had pretreatment computed tomography images, which were used to assess total skeletal muscle (SM); low- and high-radiodensity SM; visceral, subcutaneous, and intramuscular adipose tissue; and mean skeletal muscle radiodensity (SMD). All the body composition parameters were normalized by the square of the stature. They were then presented on average and at the 5th, 50th and 95th percentiles. The correlation of these parameters with age, BMI, and cancer stage was tested, and then a multiple linear regression analysis was performed. P ≤ 0.05 was accepted as statistically significant.

RESULTS

BMI was associated with body fat parameters and low-radiodensity SM index; cancer stage was associated with SM index, mean SMD, and high-radiodensity SM index.

CONCLUSION

This study provides age, stage, and BMI specific percentiles for body composition parameters, which allowed an in-depth interpretation of how such body compartments, especially the low/high SM sub-ranges, varies according to these stratification variables.

Protocol for understanding acute sarcopenia: a cohort study to characterise changes in muscle quantity and physical function in older adults following hospitalisation

BACKGROUND

Older adults are vulnerable to the effects of acute sarcopenia (acute muscle insufficiency) following hospitalisation. However, this condition remains poorly characterised to date. It is hypothesised that acute sarcopenia arises due to a combination of bed rest and inflammatory surge. This study aims to characterise changes in muscle quantity and function, determining which factors (clinical and biological) are most predictive, and how these relate to change in physical function at 13 weeks.

METHODS

This study will include three groups of patients aged 70 years and older; patients undergoing elective colorectal surgery, patients admitted for emergency abdominal surgery, and patients admitted under general medicine with acute bacterial infections. Changes in muscle quantity (Bilateral Anterior Thigh Thickness with ultrasound and bioelectrical impedance analysis) and muscle function (muscle strength, physical performance) within 1 week of hospitalisation or surgery will be characterised, with follow-up of patients at 13 weeks. Physical function will be measured using the Patient Reported Outcome Measures Information System, and the Short Physical Performance Battery (or gait speed alone within 1 week of surgery).

DISCUSSION

This study will fully characterise changes in muscle quantity and function in hospitalised older adults and enable risk stratification towards targeted interventions in clinical practice. The results of this study will inform further research involving interventions to ameliorate changes.

TRIAL REGISTRATION

ClinicalTrials.gov Identifier: NCT03858192 ; Prospectively registered 28th February 2019.

Preoperative assessment of skeletal muscle mass during magnetic resonance enterography in patients with Crohn's disease

Measurement of the psoas muscle area has been applied to estimate lean muscle mass as a surrogate marker of sarcopenia, but there is a paucity of evidence regarding the influence of sarcopenia on clinical outcomes following inflammatory bowel disease surgery. The aim of this study was to evaluate the association between MRI enterography defined sarcopenia and postoperative complications in patients undergoing elective ileocaecal resection for Crohn’s disease. To obtain cross sectional area measurement of the psoas muscle, the freehand area tool was used to trace the margin of each psoas muscle at the level of L4, with the sum recorded as Total Psoas Area (TPA). The total cross sectional muscle area of the abdominal wall was recorded as Skeletal Muscle Area (SMA), while myosteatosis was measured by normalising the psoas muscle intensity with the mean intensity of the cerebrospinal fluid. The primary outcome was the incidence of 30-day postoperative complications in patients in the lowest quartile of TPA and SMA. 31 patients were included and ten patients (32.25%) developed postoperative complications within 30 days of surgery. The cut-off values for the lowest quartile for TPA were 11.93 cm² in men and 9.77 cm² in women, including a total of 8 patients (25.8%) with 5 patients in this group (62.5%) developing postoperative complications and 3 patients (37.5%) Clavien-Dindo class ≥ 3 complications. The cut-off values for the lowest quartile for SMA were 73.49 cm² in men and 65.85 cm² in women, with 4 patients out of 8 (50%) developing postoperative complications. Psoas muscle cross sectional area and skeletal mass area can be estimated on Magnetic Resonance Enterography as surrogate markers of sarcopenia with high inter-observer agreement.

Quantification of skeletal muscle mass: sarcopenia as a marker of overall health in children and adults

Sarcopenia is defined as the loss of muscle mass or function and has been associated with increased morbidity and mortality in a variety of diseased populations. Sarcopenia results from a higher rate of muscle protein degradation compared to protein synthesis and is an important marker of metabolic status related to nutrition and physical activity. The diagnosis of sarcopenia is accomplished by clinical assessment demonstrating decreased muscle function and radiographic confirmation of decreased muscle mass, via dual X-ray absorptiometry, bioelectric impedance or cross-sectional imaging with CT or MRI. However, normative data for skeletal muscle mass are lacking, especially for children and young adults. Additionally, studies of skeletal muscle mass by cross-sectional imaging in children are scarce. Here, we review the concept of sarcopenia with an emphasis on its relevance in the pediatric population.

Nutrition interventions to treat low muscle mass in cancer

Many patients with cancer experience poor nutritional status, which detrimentally impacts clinical outcomes. Poor nutritional status in cancer is primarily manifested by severe muscle mass (MM) depletion, which may occur at any stage (from curative to palliative) and often co-exists with obesity. The objective of this article was to discuss gaps and opportunities related to the role of nutrition in preventing and reversing low MM in cancer. It also provides a narrative review of relevant nutritional interventions for patients capable of oral intake. The impact of nutrition interventions to prevent/treat low MM in cancer is not well understood, potentially due to the limited number of studies and of clinically viable, accurate body composition assessment tools. Additionally, the type of study designs, inclusion criteria, length of intervention, and choice of nutritional strategies have not been optimal, likely underestimating the anabolic potential of nutrition interventions. Nutrition studies are also often of short duration, and interventions that adapt to the metabolic and behavioural changes during the clinical journey are needed. We discuss energy requirements (25-30 kcal/kg/day) and interventions of protein (1.0-1.5 g/kg/day), branched-chain amino acids (leucine: 2-4 g/day), β-hydroxy β-methylbutyrate (3 g/day), glutamine (0.3 g/kg/day), carnitine (4-6 g/day), creatine (5 g/day), fish oil/eicosapentanoic acid (2.0-2.2 g/day EPA and 1.5 g/day DHA), vitamin/minerals (e.g. vitamin D: 600-800 international units per day), and multimodal approaches (nutrition, exercise, and pharmaceutical) to countermeasure low MM in cancer. Although the evidence is variable by modality type, interventions were generally not specifically studied in the context of cancer. Understanding patients' nutritional requirements could lead to targeted prescriptions to prevent or attenuate low MM in cancer, with the overall aim of minimizing muscle loss during anti-cancer therapy and maximizing muscle anabolism during recovery. It is anticipated that this will, in turn, improve overall health and prognostication including tolerance to treatment and survival. However, oncology-specific interventions with more robust study designs are needed to facilitate these goals.

Sarcopenia and myosteatosis at presentation adversely affect survival after esophagectomy for esophageal cancer

Background Esophageal cancer remains a disease with poor survival and many complications. Measuring muscle mass and quality can identify patients with diminished muscle mass (sarcopenia) and muscle fat infiltration (myosteatosis). We studied the impact of sarcopenia and myosteatosis in resectable esophageal cancer on overall survival and complications. Patients and methods 139 patients received a radical esophagectomy. Skeletal muscle area (SMA) and muscle attenuation (MA) in CT images at L3 level were recorded and groups with and without sarcopenia and myosteatosis were compared for overall survival (OS), perioperative mortality, conduit complications, pleuropulmonary complications, respiratory failure requiring mechanical ventilation and other significant complications. Results Prevalence of sarcopenia and myosteatosis at presentation was 16.5% and 51.8%, respectively. Both were associated with decreased OS. Median survival was 18.3 months (CI 5.4-31.1) vs 31.0 months (CI 7.4-54.6) for sarcopenia/no sarcopenia (log rank p = 0.042) and 19.0 months (CI 13.3-24.7) vs 57.1 months (CI 15.2-99.0) for myosteatosis (log rank p = 0.044), respectively. A relationship between sarcopenia and myosteatosis and other negative outcomes after esophagectomy could not be established. Conclusions Sarcopenia and myosteatosis before esophagectomy are associated with decreased overall survival but not with more frequent perioperative complications. Identification of patients at risk can guide therapeutic decisions and interventions aimed at replenishing muscle reserves.

The impact of preoperative sarcopenia on postoperative complications following esophagectomy for esophageal neoplasia: a systematic review and meta-analysis

Esophageal cancer is characterized by profound changes in body composition due to dysphagia and generalized cachexia. Sarcopenia or muscle wasting is a component of cachexia associated with poor postoperative performance status. The skeletal muscle index (SMI) calculated by computed tomography scans at the level of the third lumbar vertebra is an easily quantifiable and reproducible measure of sarcopenia. The aim of this meta-analysis is to investigate the impact of preoperative sarcopenia (low SMI) on postoperative complications after esophagectomy for neoplastic lesions. In this context, a comprehensive literature search was undertaken to identify studies reporting short-term postoperative outcomes in relation to their preoperative SMI values. Cumulative risk ratios (RR) and risk differences (RD) and their respective 95% confidence intervals (CIs) were calculated using a random-effect model. A total of 11 studies incorporating 1,979 total patients (964 patients with sarcopeniaversus 1,015 without sarcopenia) were included in the final analysis. The results demonstrated a significant increase in overall morbidity (RR 1.16, 95% CI 1.01-1.33), respiratory complications (RR 1.64, 95% CI 1.21-2.22) and anastomotic leaks (RR 1.39, 95% CI 1.10-1.76) in patients with sarcopenia. No statistically significant difference was noted in overall mortality (RD 0, 95% CI -0.02-0.02) or Clavien-Dindo grade III or greater complications (RR 1.17, 95% CI 0.96-1.42). The above results demonstrate the validity of the SMI as a predictive factor for post-esophagectomy complications. Although the risk associated with sarcopenia is not prohibitive for surgery, patients with low SMI require closer vigilance during their postoperative course due to the increased propensity for respiratory and anastomotic complications.

Radiographic assessment of sarcopenia in the trauma setting: a systematic review

Background

Compared with similarly injured patients of a younger age, elderly patients have worse outcomes from acute injury. One factor adversely affecting outcomes is sarcopenia, which has been assessed in healthy elderly populations through established clinical and radiological criteria. However, in the acute care setting, no such criteria have been established. Sarcopenia has been opportunistically assessed via radiographic means but there is as of yet no gold standard. The purpose of this review is to summarize the radiological methods used to diagnose sarcopenia in the acute care setting, and suggest ways in which these methods may lead to a consensus definition of sarcopenia and its relationship to patient outcomes.

Methods

A systematic survey of medical databases was conducted, with 902 unique publications identified. After screening and application of inclusion and exclusion criteria, data regarding study population, outcome, imaging modality, and criteria for assessment of sarcopenia were extracted from 20 studies. Quality was assessed with the Newcastle-Ottawa Scale.

Results

CT was the imaging modality for 18 of the studies, with total psoas muscle cross-sectional area at the level of L3 and L4 being the dominant method for assessing sarcopenia. Adjustment for body morphology most commonly used patient height or L4 vertebral body area. The majority of articles found radiographically assessed sarcopenia to be significantly correlated to outcomes such as mortality, length of hospital stay, morbidity, and in-hospital complications

Conclusions

Establishing a consistent definition would strengthen its applicability and generalizability to admission and discharge planning.

Level of evidence

Systematic review, level III.

Reference Values for Skeletal Muscle Mass - Current Concepts and Methodological Considerations

Assessment of a low skeletal muscle mass (SM) is important for diagnosis of ageing and disease-associated sarcopenia and is hindered by heterogeneous methods and terminologies that lead to differences in diagnostic criteria among studies and even among consensus definitions. The aim of this review was to analyze and summarize previously published cut-offs for SM applied in clinical and research settings and to facilitate comparison of results between studies. Multiple published reference values for discrepant parameters of SM were identified from 64 studies and the underlying methodological assumptions and limitations are compared including different concepts for normalization of SM for body size and fat mass (FM). Single computed tomography or magnetic resonance imaging images and appendicular lean soft tissue by dual X-ray absorptiometry (DXA) or bioelectrical impedance analysis (BIA) are taken as a valid substitute of total SM because they show a high correlation with results from whole body imaging in cross-sectional and longitudinal analyses. However, the random error of these methods limits the applicability of these substitutes in the assessment of individual cases and together with the systematic error limits the accurate detection of changes in SM. Adverse effects of obesity on muscle quality and function may lead to an underestimation of sarcopenia in obesity and may justify normalization of SM for FM. In conclusion, results for SM can only be compared with reference values using the same method, BIA- or DXA-device and an appropriate reference population. Limitations of proxies for total SM as well as normalization of SM for FM are important content-related issues that need to be considered in longitudinal studies, populations with obesity or older subjects.

Prenatal exposure to di-(2-ethylhexyl) phthalate and decreased skeletal muscle mass in 6-year-old children: A prospective birth cohort study

BACKGROUND/AIM

Phthalate is a well-known endocrine-disrupting chemical that has anti-androgenic effects. Although there are several studies on the relationship between body composition and phthalate, studies that investigated the effects of phthalate on skeletal muscle during childhood are lacking.

METHODS

We analyzed data from 481 mother-and-child pairs enrolled in the Environment and Development of Children cohort in South Korea. We examined the association between phthalate metabolites (mono [2-ethyl-5-hydroxyhexyl] phthalate [MEHHP], mono [2-ethyl-5-oxohexyl] phthalate [MEOHP], molar sum of MEHHP and MEOHP [Σ DEHP], and mono-n-butyl phthalate [MnBP]) in prenatal maternal urine and children's urine at the age of 6, and body composition indices (body mass index [BMI] z-score, percentage of fat mass, fat mass index, percentage of skeletal muscle, and the skeletal muscle index [SMI]) measured when the child was 6 years using a bioelectrical impedance analyzer.

RESULTS

A 2-fold increase in Σ DEHP and MnBP in the prenatal maternal urine was significantly associated with a -0.07 unit (95% CI: -0.11, -0.03) and -0.09 unit (95% CI: -0.14, -0.03) change in SMI, respectively, in 6-year old girls alone. BMI z-score was also negatively associated with a 2-fold increase in MEHHP and MnBP in prenatal maternal urine as -0.11 unit (95% CI: -0.22, -0.01) and -0.15 unit (95% CI: -0.28, -0.02) change, respectively, only among girls. Among boys, phthalate metabolites in the prenatal and children's urine were not significantly associated with any body composition indices.

CONCLUSIONS

Our longitudinal study shows that high levels of prenatal exposure to phthalates are significantly associated with decreased SMI among girls. We can postulate that anti-androgenic effects of phthalates during pregnancy may affect girl offspring's muscle growth.