Psoas Muscle Cross-sectional Area as a Measure of Whole-body Lean Muscle Mass in Maintenance Hemodialysis Patients

Georg Schmorl Prize of the German Spine Society (DWG) 2023: the influence of sarcopenia and paraspinal muscle composition on patient-reported outcomes: a prospective investigation of lumbar spinal fusion patients with 12-month follow-up

PURPOSE

This study aimed to investigate the impact of sarcopenia and lumbar paraspinal muscle composition (PMC) on patient-reported outcomes (PROs) after lumbar fusion surgery with 12-month follow-up (12 M-FU).

METHODS

A prospective investigation of patients undergoing elective lumbar fusion was conducted. Preoperative MRI-based evaluation of the cross-sectional area (CSA), the functional CSA (fCSA), and the fat infiltration(FI) of the posterior paraspinal muscles (PPM) and the psoas muscle at level L3 was performed. Sarcopenia was defined by the psoas muscle index (PMI) at L3 (CSAPsoas [cm2]/(patients' height [m])2). PROs included Oswestry Disability Index (ODI), 12-item Short Form Healthy Survey with Physical (PCS-12) and Mental Component Scores (MCS-12) and Numerical Rating Scale back and leg (NRS-L) pain before surgery and 12 months postoperatively. Univariate and multivariable regression determined associations among sarcopenia, PMC and PROs.

RESULTS

135 patients (52.6% female, 62.1 years, BMI 29.1 kg/m2) were analyzed. The univariate analysis demonstrated that a higher FI (PPM) was associated with worse ODI outcomes at 12 M-FU in males. Sarcopenia (PMI) and higher FI (PPM) were associated with worse ODI and MCS-12 at 12 M-FU in females. Sarcopenia and higher FI of the PPM are associated with worse PCS-12 and more leg pain in females. In the multivariable analysis, a higher preoperative FI of the PPM (β = 0.442; p = 0.012) and lower FI of the psoas (β = -0.439; p = 0.029) were associated with a worse ODI at 12 M-FU after adjusting for covariates.

CONCLUSIONS

Preoperative FI of the psoas and the PPM are associated with worse ODI outcomes one year after lumbar fusion. Sarcopenia is associated with worse ODI, PCS-12 and NRS-L in females, but not males. Considering sex differences, PMI and FI of the PPM might be used to counsel patients on their expectations for health-related quality of life after lumbar fusion.

Association of Psoas Muscle Mass at Intensive Care Unit Admission With Physical Function and Post-discharge Destination in Survivors of Critical Illness

OBJECTIVE

Survivors of critical illness may have physical impairments, known as post-intensive care syndrome (PICS). Early screening for the risk of PICS is recommended to prevent PICS. Skeletal muscle mass is a clinically important indicator associated with various outcomes. This study aimed to examine the association of psoas muscle mass at intensive care unit (ICU) admission with the destination and physical function at hospital discharge.

METHODS

In this single-center retrospective cohort study, we reviewed the medical records of adult patients who had required emergency ICU admission and who had been intubated and mechanically ventilated. Psoas major muscle was measured as an indicator of skeletal muscle mass from abdominal computed tomography images at ICU admission. Physical function was assessed using the functional status score for the ICU and ICU mobility scale at hospital discharge. Multinomial logistic and multivariable linear regression were used to analyze the associations of the psoas muscle mass with the discharge destination and physical function at discharge.

RESULTS

We enrolled 124 patients (79 men and 45 women) with a median (interquartile range) age of 72.0 (62.0-80.0) years; 39 (31.5%) were discharged to home, 50 (40.3%) were transferred to rehabilitation wards, and 35 (28.2%) were transferred to long-term care settings. The psoas muscle area and volume were 16.9 (11.3-20.6) cm2 and 228.3 (180.2-282.0) cm3 in home discharge patients, 17.5 (11.5-21.5) cm2 and 248.4 (162.0-311.4) cm3 in rehabilitation ward patients, and 15.9 (10.3-19.5) cm2 and 184.0 (137.0-251.1) cm3 in long-term care patients. The areas and volumes of the psoas muscle were not significantly different in the three groups. Furthermore, psoas muscle mass was not significantly associated with the discharge destination and physical function.

CONCLUSIONS

Discharge destination and physical function at hospital discharge were not significantly associated with psoas muscle mass at ICU admission.

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

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

Correlation between preoperative CT scan of the paraspinal, psoas, and gluteus muscles and postoperative ambulatory status in patients with femoral neck fractures

BACKGROUND

This study aimed to investigate the relationship between femoral neck fractures and sarcopenia.

METHODS

This was a retrospective analysis of 92 patients with femoral neck fractures, from September 2017 to March 2020, who were classified into high ambulatory status (HG) and low ambulatory status (LG) groups. Ambulatory status was assessed before surgery, one week after surgery, at discharge, and during the final follow-up. To evaluate sarcopenia, muscle mass and fatty degeneration of the muscles were measured using preoperative CT. An axial slice of the superior end of the L5 vertebra was used to evaluate the paraspinal and psoas muscles, a slice of the superior end of the femoral head for the gluteus maximus muscle, and a slice of the inferior end of the sacroiliac joint for the gluteus medius muscle. The degeneration of the muscles was evaluated according to the Goutallier classification.

RESULTS

The cross-sectional area of the gluteus medius and paraspinal muscles was significantly correlated with ambulatory status before the injury, at discharge, and during the final follow-up.

CONCLUSIONS

Measurement of the gluteus medius and paraspinal muscles has the potential to evaluate sarcopenia and predict ambulatory status after femoral neck fractures.

Concordance between muscle mass assessed by bioelectrical impedance analysis and by muscle ultrasound: a cross-sectional study in a cohort of patients on chronic hemodialysis

BACKGROUND

Sarcopenia is a common problem in hemodialysis (HD) patients, and it is diagnosed by low muscle mass, strength and/or low physical performance. Muscle ultrasound (US) is a non-invasive portable tool that might be used for assessment of muscle mass. The aim of the current study was to investigate the concordance between muscle US and bioelectrical impedance analysis (BIA) in diagnosis of sarcopenia in HD patients.

METHODS

This cross-sectional study included 41 HD patients. Sarcopenia was diagnosed according to the European Working Group on Sarcopenia in Older People (EWGSOP). The skeletal mass index was measured by BIA and the muscle strength was measured by handgrip strength. Muscle US was used to measure cross-sectional area (CSA) and thickness of quadriceps and biceps muscles.

RESULTS

The current study included 41 patients on HD (25 males), with a mean (SD) age of 44.18 (13.11) years and a median HD duration of 48 months. Sarcopenia was diagnosed in 58.5% of the patients. Patients with sarcopenia had significantly lower quadriceps muscle CSA than those without sarcopenia. The optimal cut-offs of quadriceps muscle CSA for both males and females for the diagnosis of sarcopenia were 2.96 and 2.92 cm2, respectively.

CONCLUSION

Sarcopenia is prevalent among Egyptian HD patients. US on quadriceps muscle CSA could be used for diagnosis of sarcopenia in these patients.

Precision MRI phenotyping of muscle volume and quality at a population scale

Introduction: Magnetic resonance imaging (MRI) enables direct measurements of muscle volume and quality, allowing for an in-depth understanding of their associations with anthropometric traits, and health conditions. However, it is unclear which muscle volume measurements: total muscle volume, regional measurements, measurements of muscle quality: intermuscular adipose tissue (IMAT) or proton density fat fraction (PDFF), are most informative and associate with relevant health conditions such as dynapenia and frailty. Methods: We have measured image-derived phenotypes (IDPs) including total and regional muscle volumes and measures of muscle quality, derived from the neck-to-knee Dixon images in 44,520 UK Biobank participants. We further segmented paraspinal muscle from 2D quantitative MRI to quantify muscle PDFF and iron concentration. We defined dynapenia based on grip strength below sex-specific cut-off points and frailty based on five criteria (weight loss, exhaustion, grip strength, low physical activity and slow walking pace). We used logistic regression to investigate the association between muscle volume and quality measurements and dynapenia and frailty. Results: Muscle volumes were significantly higher in male compared with female participants, even after correcting for height while, IMAT (corrected for muscle volume) and paraspinal muscle PDFF were significantly higher in female compared with male participants. From the overall cohort, 7.6% (N = 3,261) were identified with dynapenia, and 1.1% (N = 455) with frailty. Dynapenia and frailty were positively associated with age and negatively associated with physical activity levels. Additionally, reduced muscle volume and quality measurements were associated with both dynapenia and frailty. In dynapenia, muscle volume IDPs were most informative, particularly total muscle exhibiting odds ratios (OR) of 0.392, while for frailty, muscle quality was found to be most informative, in particular thigh IMAT volume indexed to height squared (OR = 1.396), both with p-values below the Bonferroni-corrected threshold (p < 8.8 × 10 - 5 ). Conclusion: Our fully automated method enables the quantification of muscle volumes and quality suitable for large population-based studies. For dynapenia, muscle volumes particularly those including greater body coverage such as total muscle are the most informative, whilst, for frailty, markers of muscle quality were the most informative IDPs. These results suggest that different measurements may have varying diagnostic values for different health conditions.

Influences of trans-theoretical model-based diet nursing intervention on sarcopenia and quality of life in maintenance hemodialysis patients

OBJECTIVE

to explore the influences of a trans-theoretical model-based diet nursing intervention on sarcopenia and quality of life in maintenance hemodialysis patients.

METHODS

the clinical data of 243 patients with maintenance hemodialysis (MHD) admitted to our hospital from January 2019 to August 2020 were retrospectively analyzed. A 1:1 orientation score matching (PSM) method was adopted, and patients with different intervention methods were matched based on gender, age, education time, dialysis age, body mass index, underlying diseases, annual income, and whether they were malnourished. Finally, 82 cases were included in the control group (routine nursing and dietary guidance) and 80 cases in the intrevention group (dietary nursing intervention based on the trans-theoretical model), respectively.

RESULTS

After PSM, 82 cases in the control group and 80 cases in the intrevention group were included in the study. After the intervention, the incidence of sarcopenia, the extracellular water rate (ECF/TBF) value, and the malnutrition rate of the intrevention group were lower than those of the control group (p < 0.05); the scores of self-care, facing difficulties, potassium intake management, salt intake management, fluid restriction management, the levels of serum albumin, prealbumin and transferrin were all higher than those of the control group (p < 0.05); the SF-36 Concise Health Scale score of the intrevention group was higher than that of the control group (p < 0.05). The 1-year survival rate in the intrevention group (95.00 %) was higher than that in the control group (85.37 %) (p < 0.05).

CONCLUSION

a TTM-based diet nursing intervention can help improve the dietary management behavior of MHD patients, prevent malnutrition, reduce the incidence of sarcopenia, and improve their quality of life and survival rate.

A Comparative Analysis of Frailty, Disability, and Sarcopenia With Patient Characteristics and Outcomes in Adult Spinal Deformity Surgery

STUDY DESIGN

Retrospective case series study.

OBJECTIVES

This study aims to compare preoperative indices, including the modified frailty index-11 (mFI-11), modified frailty index-5 (mFI-5), Oswestry Disability Index (ODI), and psoas muscle index (PMI), as they relate to outcomes in adult spinal deformity (ASD) surgery.

METHODS

We identified 235 patients who underwent thoracolumbar ASD surgery (≥4 levels). The mFI-11, mFI-5, ODI, and PMI were determined from preoperative visits and correlated to outcome measures, including perioperative transfusion, duration of anesthesia, hospital and ICU length of stay (LOS), discharge disposition, readmission, change in ODI at last follow-up, revision surgery, and mortality.

RESULTS

Our cohort had a mean age of 69.6 years and a male:female ratio of 1:2 with 177 undergoing an index surgery and 58 patients presenting after a failed multilevel fusion. The average number of levels fused was 9.3. The mFI-11 and mFI-5 were similar in predicting the need for intraoperative and postoperative transfusion. However, the mFI-11 was able to predict longer ICU and hospital LOS and mortality. The average preoperative ODI was 44.9% with an average decrease of 10.1% at the last follow-up. Preoperative ODI was the most significant predictor of postoperative change of ODI. Sarcopenia, defined as the lowest quartile of PMI values measured at L3 and L4, was not associated with any meaningful outcomes.

CONCLUSION

The mFI-11 better correlated with outcomes, indicating its increased prognostic value compared to other preoperative indices in ASD surgery. Preoperative ODI remains a significant predictor of postoperative change in ODI when evaluating ASD patients.

Association Between Preoperative Sarcopenia and Early Postoperative Outcomes in Pediatric Patients Undergoing Total Correction of Tetralogy of Fallot: A Retrospective Cohort Study

OBJECTIVES

To identify the association between preoperative low muscle mass and early postoperative outcomes in pediatric patients undergoing total correction of tetralogy of Fallot (TOF).

DESIGN

A retrospective cohort study.

SETTING

A single university hospital in Seoul, South Korea.

PARTICIPANTS

Pediatric patients (≤3 years) who underwent total correction of TOF between May 2008 and February 2018.

INTERVENTIONS

None.

MEASUREMENTS AND MAIN RESULTS

Cross-sectional areas of the pectoralis and erector spinae muscles were measured using preoperative chest computed tomography (CT) scans, and adjusted to body surface area to define muscle mass index. The patients were divided into sarcopenia, presarcopenia, and no sarcopenia groups based on cutoff values determined using the mean and SD of the muscle mass index in the third z-weight quintile. Of a total of 330 patients included in the final analysis, 13 were associated with the sarcopenia group, 57 in the presarcopenia group, and 260 in the no sarcopenia group. The sarcopenia group exhibited a higher incidence of major adverse events than the presarcopenia and no sarcopenia groups, respectively (38% v 25% v 18%; p = 0.033). Logistic regression analyses revealed that only younger age at the time of surgery was significantly associated with major adverse events (odds ratio 0.82; 95% CI 0.72-0.94, p = 0.003).

CONCLUSIONS

The incidence of sarcopenia, as assessed by preoperative chest CT, was low in pediatric patients undergoing total correction of TOF, and preoperative sarcopenia did not predict early postoperative major adverse events.

Psoas Muscle Index as a Predictor of Perioperative Outcomes in Geriatric Patients Undergoing Spine Surgery

STUDY DESIGN

Single-center retrospective study.

OBJECTIVE

The objective of this study was to evaluate the association of psoas muscle mass defined sarcopenia with perioperative outcomes in geriatric patients undergoing elective spine surgery.

METHODS

We included geriatric patients undergoing thoracolumbar spinal surgery. Total psoas surface area (TPA) was measured on preoperative axial computerized tomography or magnetic resonance imaging at the L3 vertebra and normalized to the L3 vertebral body area. Patients were divided into quartiles by normalized TPA, and the fourth quartile (Q4) was compared to quartiles 1-3 (Q1-3). Outcomes included perioperative transfusions, length of stay (LOS), delirium, pseudoarthrosis, readmission, discharge disposition, revision surgery, and mortality.

RESULTS

Of the patients who met inclusion criteria (n = 196), the average age was 73.4 y, with 48 patients in Q4 and 148 patients in Q1-3. Q4 normalized TPA cut-off was <1.05. Differences in Q4 preoperative characteristics included significantly lower body mass index, baseline creatinine, and a greater proportion of females (Table 1). Q4 patients received significantly more postoperative red blood cell and platelet transfusions and had longer ICU LOS (P < .05; Table 2). There was no difference in intraoperative transfusion volumes, delirium, initiation of walking, discharge disposition, readmission, pseudoarthrosis, or revision surgery (Tables 2 and 3). Mortality during follow-up was higher in Q4 but was not statistically significant (P = .075).

CONCLUSION

Preoperative TPA in geriatric patients undergoing elective spine surgery is associated with increased need for intensive care and postoperative blood transfusion. Preoperative normalized TPA is a convenient measurement and could be included in geriatric preoperative risk assessment algorithms.

Newly developed sarcopenia after liver transplantation, determined by a fully automated 3D muscle volume estimation on abdominal CT, can predict post-transplant diabetes mellitus and poor survival outcomes

BACKGROUND

Loss of muscle mass is the most common complication of end-stage liver disease and negatively affects outcomes for liver transplantation (LT) recipients. We aimed to determine the prognostic value of a fully automated three-dimensional (3D) muscle volume estimation using deep learning algorithms on abdominal CT in patients who underwent liver transplantation (LT).

METHODS

This retrospective study included 107 patients who underwent LT from 2014 to 2015. Serial CT scans, including pre-LT and 1- and 2-year follow-ups were performed. From the CT scans, deep learning-based automated body composition segmentation software was used to calculate muscle volumes in 3D. Sarcopenia was calculated by dividing average skeletal muscle area by height squared. Newly developed-(ND) sarcopenia was defined as the onset of sarcopenia 1 or 2 years after LT in patients without a history of sarcopenia before LT. Patients' clinical characteristics, including post-transplant diabetes mellitus (PTDM) and Model for end-stage liver disease score, were compared according to the presence or absence of sarcopenia after LT. A subgroup analysis was performed in the post-LT sarcopenic group. The Kaplan-Meier method was used for overall survival (OS).

RESULTS

Patients with ND-sarcopenia had poorer OS than those who did not (P = 0.04, hazard ratio [HR], 3.34; 95% confidence interval [CI] 1.05 - 10.7). In the subgroup analysis for post-LT sarcopenia (n = 94), 34 patients (36.2%) had ND-sarcopenia. Patients with ND-sarcopenia had significantly worse OS (P = 0.002, HR 7.12; 95% CI 2.00 - 25.32) and higher PTDM occurrence rates (P = 0.02, HR 4.93; 95% CI 1.18 - 20.54) than those with sarcopenia prior to LT.

CONCLUSION

ND-sarcopenia determined by muscle volume on abdominal CT can predict poor survival outcomes and the occurrence of PTDM for LT recipients.

Comparative analysis of the sarcopenia and HALP score on postoperative outcomes in pancreatic cancer patients after pancreatoduodenectomy

BACKGROUND

Sarcopenia and HALP (Hemoglobin, Albumin, Lymphocyte, and Platelet) scores are factors commonly associated with postoperative outcomes used in cancer patients. This study aims to evaluate the effect of these two prognostic factors on postoperative outcomes in operated pancreatic cancer patients and their correlation with each other.

METHODS

The study is a single-center, retrospective study conducted with 179 patients diagnosed with pancreatic adenocarcinoma after pancreatoduodenectomy (PD) between January 2012 and January 2022. The Psoas muscular index (PMI) and HALP scores of the patients were calculated. Cut-off values were determined in order to determine the nutritional status of the patients and to group them. The cut-off value of the HALP score was determined according to survival status. In addition, the clinical data and pathological findings of tumors were collected. These two parameters were evaluated in terms of length of hospital stay, postoperative complication rates, fistula development, and overall survival, and their correlations with each other were examined.

RESULTS

Of the patients, 74 (41.3%) were female, and 105 (58.7%) were male. According to PMI cut-off values, 83 (46.4%) patients were in the sarcopenia group. According to the HALP score cut-off values, 77 (43.1%) patients were in the low HALP group. Sarcopenia and Low HALP group had a higher risk of death (respectively Hazard ratio:5.67, CI:3.58-8.98, Hazard ratio:5.95, CI: 3.72-9.52) (p < 0.001). There was a moderate correlation between PMI and HALP score (rs = 0.34, p = 0.01). The correlation in these values was higher in the female gender.

CONCLUSIONS

In line with the data obtained from our study, HALP score and sarcopenia are among the important parameters used to evaluate postoperative complications and provide information about survival. Patients with a low HALP score and sarcopenic have an increased likelihood of developing postoperative complications and a lower survival.

The effects of muscle mass and quality on mortality of patients with acute kidney injury requiring continuous renal replacement therapy

This study examined the effects of muscle mass on mortality in patients with acute kidney injury requiring continuous renal replacement therapy. It was conducted in eight medical centers between 2006 and 2021. The data of 2200 patients over the age of 18 years with acute kidney injury who required continuous renal replacement therapy were retrospectively collected. Skeletal muscle areas, categorized into normal and low attenuation muscle areas, were obtained from computed tomography images at the level of the third lumbar vertebra. Cox proportional hazards models were used to investigate the association between mortality within 1, 3, and 30 days and skeletal muscle index. Sixty percent of patients were male, and the 30-day mortality rate was 52%. Increased skeletal muscle areas/body mass index was associated with decreased mortality risk. We also identified a 26% decreased risk of low attenuation muscle area/body mass index on mortality. We established that muscle mass had protective effects on the mortality of patients with acute kidney injury requiring continuous renal replacement therapy. This study showed that muscle mass is a significant determinant of mortality, even if the density is low.

Ultrasound and magnetic resonance imaging as diagnostic tools for sarcopenia in immune-mediated rheumatic diseases (IMRDs)

Sarcopenia is characterized by loss of muscle mass, altered muscle composition, fat and fibrous tissue infiltration, and abnormal innervation, especially in older individuals with immune-mediated rheumatic diseases (IMRDs). Several techniques for measuring muscle mass, strength, and performance have emerged in recent decades. The portable dynamometer and gait speed represent the most frequently used tools for the evaluation of muscle strength and physical efficiency, respectively. Aside from dual-energy, X-ray, absorptiometry, and bioelectrical impedance analysis, ultrasound (US) and magnetic resonance imaging (MRI) techniques appear to have a potential role in evaluating muscle mass and composition. US and MRI have been shown to accurately identify sarcopenic biomarkers such as inflammation (edema), fatty infiltration (myosteatosis), alterations in muscle fibers, and muscular atrophy in patients with IMRDs. US is a low-cost, easy-to-use, and safe imaging method for assessing muscle mass, quality, architecture, and biomechanical function. This review summarizes the evidence for using US and MRI to assess sarcopenia.

Pretransplant Psoas Muscle Cross-Sectional Area and Postkidney Transplant Outcomes

BACKGROUND

Sarcopenia is associated with adverse outcomes in end-stage kidney disease. We evaluated if pretransplant sarcopenia affects posttransplant outcomes in kidney transplant (KT) recipients.

METHODS

In this single-center retrospective study of adult patients with end-stage kidney disease, we analyzed the association between pre-KT psoas muscle cross-sectional area and critical posttransplant outcomes of decline in estimated glomerular filtration rate (eGFR), graft loss, rehospitalization, and mortality using Cox proportional hazard model adjusted for age, sex, and race.

RESULTS

Pre-KT abdomen and pelvic computed tomography scans performed during evaluation for KT eligibility were available for 573 KT recipients. Of these, 465 KT recipients received kidney alone transplant, 71 received simultaneous liver kidney transplant (SLK), and 37 received simultaneous pancreas kidney transplant (SPK). Patients were 49 (SD, 13) years old, 16% Black, and 60% men. For kidney alone transplant recipients, a higher psoas muscle cross-sectional area was associated with a shorter length of hospitalization (β coefficient = -0.003; 95% CI, -0.005 to -0.0007). Conversely, pre-KT psoas muscle cross-sectional area did not predict decline in eGFR, graft loss, mortality, or early rehospitalization. For SLK recipients, psoas muscle cross-sectional area did not predict any of the priori outcomes. For SPK recipients, higher pretransplant psoas muscle cross-sectional area predicted a longer length of hospitalization (β coefficient = 0.03; 95% CI, 0.01-0.05). There was no association between psoas muscle cross-sectional area and other outcomes assessed.

CONCLUSIONS

Pretransplant psoas muscle cross-sectional areas are not predictive of post-transplant decline in eGFR, graft loss, rehospitalization or mortality in kidney alone, SPK, or SLK transplants.

The relationship between radiological paraspinal lumbar measures and clinical measures of sarcopenia in older patients with chronic lower back pain

Objectives

Sarcopenia is postulated to be an influential factor in chronic low back pain. The aim of this study is to evaluate the relationship between traditional clinical measures of sarcopenia and novel radiographic methods which evaluate overall muscle status, such as adjusted psoas cross-sectional area (APCSA) and degree of fat infiltration (%FI) in paraspinal muscles, in patients with chronic low back pain.

Methods

Prospective study performed at our institution from 01/01/19-01/04/19. Inclusion criteria were patients ≥65 years old not requiring surgical intervention presenting to a low back pain assessment clinic.

Results

25 patients were identified (mean age: 73 years, 62% male). On spearman's analyses, %FI shared a significant relationship with hand grip strength (r = -0.37; p=0.03), chair rise (r=0.38; p=0.03), SC (r=0.64; p<0.01), and visual analogue scale scores (r=-0.14; p=0.02). Comparably, a statistically significant correlation was evident between APCSA and %FI (r=-0.40; p=0.02) on analysis.

Conclusion

The results of our study demonstrate a statistically significant relationship between APCSA and %FI in the multifidus and erector spinae muscles. Further significant associations of relatability were depicted with traditional clinical measures of sarcopenia. Thus, %FI may be a supplemental indicator of the sarcopenic status of patients presenting with chronic low back pain.

Clinical Impact of Nutritional Status and Sarcopenia in Pediatric Patients with Bone and Soft Tissue Sarcomas: A Pilot Retrospective Study (SarcoPed)

BACKGROUND

We evaluated nutritional and sarcopenia status and their clinical impact in pediatric patients affected by bone and soft tissue sarcomas.

METHODS

Body mass index (BMI), prognostic nutritional index (PNI), and total psoas muscle area (tPMA) at diagnosis and after 12 months were analyzed. tPMA was measured from single cross-sectional computed tomography (CT) images at L4-L5. Age-specific and sex-specific tPMA Z-scores were retrieved from an online calculator.

RESULTS

A total of 21 patients were identified between February 2013 and December 2018. Twelve patients (57.1%) experienced sarcopenia at diagnosis, although not statistically associated with overall survival (OS) (p = 0.09). BMI Z-score, PNI, and tPMA Z-score significantly decreased between diagnosis and after 12 months of treatment (p < 0.05). Univariate analysis showed significant associations between poor OS and the presence of metastasis (p = 0.008), the absence of surgery (p = 0.005), PNI decrease (p = 0.027), and the reduction in tPMA > 25% (p = 0.042) over the 12 months.

CONCLUSIONS

Sarcopenia affects more than half of the patients at diagnosis. Decreased PNI during 12 months of treatment has significant predictive value for OS. The role of tPMA derived from CT scan among pediatric patients with sarcoma should be investigated in further prospective and larger studies.

Skeletal muscle mass as a marker to predict outcomes in children and young adults with cancer

PURPOSE

Nutrition is an important outcome predictor in oncology patients including treatment response, physical disability, quality of life, and overall survival. Sarcopenia (loss of skeletal muscle mass and function) is a demonstrated marker of nutritional status in adults, but data are more limited in children. The purpose of this study was to evaluate whether total psoas muscle area (tPMA) measured at the time of cancer diagnosis predicts overall survival (OS), disease free survival (DFS), or number of days neutropenic.

METHODS

A retrospective study was performed. tPMA was measured at the L3 and L4 mid-lumbar vertebral body level by a single reviewer on cross-sectional imaging studies performed within 2 weeks of primary oncologic diagnosis for all oncology patients who received their primary therapy at Cincinnati Children's Hospital between 1/1/2000 and 12/31/2013. Spearman's correlation was used to assess the association between tPMA and OS, DFS, days neutropenic, and adjusted days neutropenic. Subanalysis was performed assessing the relationship of tumor type and age at diagnosis with each parameter.

RESULTS

164 patients (median age 9.9 years; 89 M/75 F) were included in the study. Days neutropenic and normalized days neutropenic were significantly but weakly negatively correlated with tPMA at L3 (r =  - 0.24, p < 0.002 and r =  - 0.18, p < 0.05 respectively) and L4 (r =  - 0.25, p < 0.002; and and r =  - 0.19, p < 0.02 respectively). At subanalysis, the correlation between anthropometric features and normalized days neutropenic was only seen with brain tumors. There was no statistically significant relationship between sarcopenia at diagnosis and DFS or OS overall or in subanalysis.

CONCLUSION

There is a weak inverse relationship between days neutropenic and psoas muscle bulk in pediatric and young adult oncology patients suggesting a relationship between nutritional status and cell recovery. Measures of sarcopenia, however, did not correlate with DFS or OS.

Association between the psoas muscle index and hospitalization for pneumonia in patients undergoing hemodialysis

Background

Although muscle mass loss and pneumonia are common and crucial issues in hemodialysis (HD) patients, few reports have focused on their association, which remains unclear. This study assessed the association between skeletal muscle mass and the incidence of pneumonia in HD patients using the psoas muscle index (PMI).

Methods

This retrospective study included 330 patients on HD who were treated at a single center between July 2011 and June 2012. The observation period was between July 2011 and June 2021. Demographic, clinical, and HD data were collected, and the associations between PMI and hospitalization due to bacterial pneumonia were evaluated using Cox proportional hazards models adjusted for patients’ background data. Additionally, the correlation between patient characteristics and PMI was evaluated using multivariable linear regression.

Results

Among 330 patients (mean age, 67.3 ± 13.3; 56.7% male; median dialysis vintage 58 months, (interquartile range [IQR] 23–124), 79 were hospitalized for pneumonia during the observation period (median observation period was 4.5 years [IQR 2.0–9.1]). The multivariable Cox proportional analysis, which was adjusted for age, sex, dialysis vintage, diabetes mellitus, and stroke history and considered death as a competing risk, indicated that decreased PMI/(standard deviation) was closely associated with the development of pneumonia (hazard ratio: 0.67, 95% confidence interval: 0.47–0.95, p = 0.03).

Conclusions

Skeletal muscle mass was associated with the development of pneumonia in patients on HD and could be a useful marker for the risk of pneumonia.

Supplementary Information

The online version contains supplementary material available at 10.1186/s12882-021-02612-7.

Pelvic muscle size and myosteatosis: Relationship with age, gender, and obesity

Purpose

To evaluate interreader performance in the measurement of the cross-sectional area and myosteatosis of pelvic skeletal muscles using fat quantification magnetic resonance imaging (MRI) and correlate with patient anthropomorphic characteristics.

Materials and Methods

A Health Insurance Portability and Accountability Act-compliant retrospective cross-sectional study was performed. Between January and April 2016, 61 patients (26 males and 35 females) underwent a lumbosacral plexus 3T MRI with a modified three-dimensional spoiled gradient echo sequence dedicated to fat quantification (mDixon Quant; Philips Healthcare). Two independent reviewers outlined muscle cross-sectional area on axial images using a freehand region of interest tool and documented proton-density fat fraction (FF) and muscle area (cm²) of the psoas, gluteus medius, gluteus maximus, and rectus femoris muscles on each side. Interreader agreement was assessed by intraclass correlation coefficient (ICC), and correlation between the measurements and subject's age, gender, and body mass index (BMI) was assessed using multiple linear regression analysis.

Results

Excellent interreader agreement was obtained (ICC ≥0.74) for all muscle groups except for the left gluteus medius area and right psoas FF which showed good agreement (0.65 and 0.61, respectively). Statistically significant (P ≤ 0.05) positive correlation was seen between the gluteal muscle FF and area with BMI, and rectus muscle FF with age and BMI. Statistically significant negative correlation between the rectus femoris area and age was also observed.

Conclusion

Fat quantification MRI is a highly reproducible imaging technique for the assessment of myosteatosis and muscle size. Intramuscular FF and cross-sectional area were correlated with age and BMI across multiple muscle groups.

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.

Body composition in patients with rheumatoid arthritis: a narrative literature review

There is growing interest in the alterations in body composition (BC) that accompany rheumatoid arthritis (RA). The purpose of this review is to (i) investigate how BC is currently measured in RA patients, (ii) describe alterations in body composition in RA patients and (iii) evaluate the effect on nutrition, physical training, and treatments; that is, corticosteroids and biologic Disease Modifying Anti-Rheumatic Disease (bDMARDs), on BC in RA patients. The primary-source literature for this review was acquired using PubMed, Scopus and Cochrane database searches for articles published up to March 2021. The Medical Subject Headings (MeSH) terms used were 'Arthritis, Rheumatoid', 'body composition', 'sarcopenia', 'obesity', 'cachexia', 'Absorptiometry, Photon' and 'Electric Impedance'. The titles and abstracts of all articles were reviewed for relevant subjects. Whole-BC measurements were usually performed using dual energy x-ray absorptiometry (DXA) to quantify lean- and fat-mass parameters. In RA patients, lean mass is lower and adiposity is higher than in healthy controls, both in men and women. The prevalence of abnormal BC conditions such as overfat, sarcopenia and sarcopenic obesity is significantly higher in RA patients than in healthy controls; these alterations in BC are observed even at an early stage of the disease. Data on the effect treatments on BC in RA patients are scarce. In the few studies published, (a) creatine supplementation and progressive resistance training induce a slight and temporary increase in lean mass, (b) exposure to corticosteroids induces a gain in fat mass and (c) tumour necrosis factor alpha (TNFα) inhibitors might be associated with a gain in fat mass, while tocilizumab might be associated with a gain in lean mass. The available data clearly demonstrate that alterations in BC occur in RA patients, but data on the effect of treatments, especially bDMARDs, are inconsistent and further studies are needed in this area.

Application of Magnetic Resonance Imaging in the Evaluation of Nutritional Status: A Literature Review with Focus on Dialysis Patients

Magnetic resonance imaging (MRI) is indispensable in clinical medicine for the morphological and tomographic evaluation of many parenchymal organs. With varied imaging methods, diverse biological information, such as the perfusion volume and measurements of metabolic products, can be obtained. In addition to conventional MRI for morphological assessment, diffusion-weighted MRI/diffusion tensor imaging is used to evaluate white matter structures in the brain; arterial spin labeling is used for cerebral blood flow evaluation; magnetic resonance elastography for fatty liver and cirrhosis evaluation; magnetic resonance spectroscopy for evaluation of metabolites in specific regions of the brain; and blood oxygenation level-dependent imaging for neurological exploration of eating behavior, obesity, and food perception. This range of applications will continue to expand in the future. Nutritional science is a multidisciplinary and all-inclusive field of research; therefore, there are many different applications of MRI. We present a literature review of MRI techniques that can be used to evaluate the nutritional status, particularly in patients on dialysis. We used MEDLINE as the information source, conducted a keyword search in PubMed, and found that, as a nutritional evaluation method, MRI has been used frequently to comprehensively and quantitatively evaluate muscle mass for the determination of body composition.

Psoas Muscle Index Defined by Computer Tomography Predicts the Presence of Postoperative Complications in Colorectal Cancer Surgery

Background and Objectives: Sarcopenia is a recognized prognostic factor for both complications and survival in cancer patients. This study aims to analyze the relationship between sarcopenia measured by psoas muscle index on computer tomography scans and the presence of postoperative complications in colorectal cancer surgery. Materials and Methods: In a prospective study we recorded data from 51 patients who underwent colorectal cancer surgery in the Mures County Clinical Hospital, Romania. Total psoas muscle area and psoas density were measured at the level of the third lumbal vertebra (L3) for further index calculation. We also evaluated the general characteristics and laboratory analyses to obtain more information about status of the patients. Short-term postoperative complications were scored according to the Clavien-Dindo classification. Results: The majority of the 51 patients were male (61%) and the median age was 65 years. More than half of the cancer was located in the rectum (56.9%), a quarter in the right colon (25.5%), the rest in the sigmoid (11.8%), and the left colon (5.9%). Twenty-one patients (41.2%) developed a complication, five (9.8%) of these were Clavien-Dindo grade 3, 4 or 5 (high grade) and sixteen (31.3%) grade 1 or 2 (low grade). The low- and high-grade groups showed a significantly lower right psoas muscle area, left psoas muscle area, total psoas muscle area, and psoas muscle index (p < 0.001 in all cases). Among laboratory analyses, a significantly lower perioperative hematocrit, hemoglobin, and albumin level were found in patients who developed complications. Furthermore we observed that an elevated serum C-reactive protein level was associated with a higher grade of complication (p < 0.043). Conclusions: The psoas muscle index (PMI) influence on the postoperative outcome is an important factor in our single center prospective study and it appears to be a good overall predictor in colorectal surgery. A lower PMI is directly associated with a low or high grade complication by Clavien-Dindo classification. Perioperative inflammatory and nutritional status evidenced by serum C-reactive protein (CRP) and albumin level influences the presence of postoperative complications.

Association of Outcomes of Spinal Cord Stimulation for Chronic Low Back Pain and Psoas Measurements Based on Size of Iliopsoas Muscles

INTRODUCTION

Patients experience variable long-term improvement in chronic back pain despite successful spinal cord stimulation (SCS) trials. Iliopsoas (IP) size has been shown to differ between patients with low back pain and healthy controls. In this study, we examine whether IP muscle cross-sectional area (CSA) is associated with SCS outcomes.

MATERIALS AND METHODS

We examined patients for whom we had lumbar MRIs 6.3 years prior to SCS and had baseline and one-year outcome data. Percent change from baseline to one year was calculated for Numeric Rating Scale (NRS), Oswestry Disability Index (ODI), Beck Depression Inventory (BDI), Pain Catastrophizing Scale (PCS), and McGill Pain Questionnaire (MPQ). Correlations between IP muscle CSA, ratio of iliopsoas muscle size to the vertebral body area (P/VBA), and the ratio of iliopsoas muscle size to BMI (P/BMI) were examined. Sex differences were considered.

RESULTS

A total of 73 subjects were included in this study including 30 females and 43 males. Males had significantly larger IP (males 15.70 ± 0.58, females 9.72 ± 0.43; p < 0.001), P/VBA (males 1.00 ± 0.04, females 0.76 ± 0.03, p < 0.001) and P/BMI ratio (males 0.51 ± 0.02, females 0.32 ± 0.01; p < 0.001) than females. In females, P/VBA predicted NRS worst pain scores (β = 0.82, p = 0.004, r² = 0.55) and BDI (β = 0.59, p = 0.02, r² = 0.24). In males, P/BMI was a significant predictor of BDI outcomes scores (β = 0.45, p = 0.03, r² = 0.16). Males who had more muscle mass measured by iliopsoas size had more depression as measured using BDI (p = 0.03, r = 0.61). Females with less muscle mass measured by P/VBA also experienced more depression (p = 0.02, r = 0.74).

CONCLUSIONS

Our study showed that psoas measurements correlated with various pain outcomes specifically. P/VBA was most predictive in females and P/BMI in males. Depression correlated with P/BMI, reinforcing the complex relationship between depression and constant chronic pain. Tertile analyses further showed a relationship between iliopsoas CSA and depression in males and females. We provide preliminary data of sex-specific psoas measurements as a risk factor for worse SCS outcomes.

Is Dysphagia in Older Patients with Parkinson's Disease Associated With Sarcopenia ?

BACKGROUND

Parkinson's Disease (PD) and sarcopenia share a number of common pathways, and they can potentially affect each other.

OBJECTIVE

We aimed to investigate the relationship between dysphagia and sarcopenia in elderly patients with PD compared to healthy controls.

METHODS

This case-control study was conducted on 54 elderly PD patients and age-, sex- and body mass index-matched 54 healthy elder persons. Demographic and disease characteristics such as disease duration, stage of disease and Unified Parkinson's disease rating scale were recorded. All subjects were assessed by 10- item Eating Assessment Tool, Gugging Swallowing Screen tests and flexible fiberoptic endoscopic evaluation of swallowing (FEES) as well as Mini nutritional test short form. Also, A simplified screening tool for assessing sarcopenia (SARC-F), five times sit-to-stand and gait speed tests as well as lumbar magnetic resonance imaging (MRI) cross-sectional area of psoas and paraspinal muscles were used for evaluation of sarcopenia. Patients were divided as «with normal swallowing» or «with dysphagia» according to the FEES results. Three groups were compared among themselves in terms of evaluation methods.

RESULTS

Sarcopenia evaluation parameters were significantly higher in patient groups compared to the control group. Moreover, muscle measurements evaluated by MRI in patients with dysphagia are lower than both patients with normal swallowing and control group (p value between 0.001 and 0.011).

CONCLUSIONS

Patients with PD have lower muscle mass compared to healthy controls, and the situation is more pronounced in dysphagic PD patients.

Large-scale analysis of iliopsoas muscle volumes in the UK Biobank

Psoas muscle measurements are frequently used as markers of sarcopenia and predictors of health. Manually measured cross-sectional areas are most commonly used, but there is a lack of consistency regarding the position of the measurement and manual annotations are not practical for large population studies. We have developed a fully automated method to measure iliopsoas muscle volume (comprised of the psoas and iliacus muscles) using a convolutional neural network. Magnetic resonance images were obtained from the UK Biobank for 5000 participants, balanced for age, gender and BMI. Ninety manual annotations were available for model training and validation. The model showed excellent performance against out-of-sample data (average dice score coefficient of 0.9046 ± 0.0058 for six-fold cross-validation). Iliopsoas muscle volumes were successfully measured in all 5000 participants. Iliopsoas volume was greater in male compared with female subjects. There was a small but significant asymmetry between left and right iliopsoas muscle volumes. We also found that iliopsoas volume was significantly related to height, BMI and age, and that there was an acceleration in muscle volume decrease in men with age. Our method provides a robust technique for measuring iliopsoas muscle volume that can be applied to large cohorts.

Skeletal Muscle Index as a Prognostic Marker for Kidney Transplantation in Older Patients

OBJECTIVE

Low skeletal muscle mass has emerged as a risk factor for mortality after liver transplantation. We evaluated the prognostic value of muscle mass on length of hospitalization and adverse outcomes after kidney transplantation in aging end-stage renal disease patients.

METHODS

One hundred twenty-two patients aged 60 years or older at the time of transplantation were retrospectively analyzed. Skeletal muscle index (SMI), evaluated by computed tomography scan, was calculated from total muscle surface area at L3 vertebral level divided by body height squared. Outcomes were compared according to SMI (namely, length of hospitalization, wound complications, combined endpoint comprising all-cause mortality, and graft failure within 1 year).

RESULTS

In male patients, by multivariate analysis, a low SMI (<42 cm²/m²) was associated with longer immediate post-transplantation hospitalization (β = 17.03 ± 4.3; P = .0002), longer total hospitalization during the first year (β = 34.3 ± 10.7; P = .002), higher rate of wound complications (odds ratio = 12.1 [1.9-77.0]; P = .008), and higher rate of the combined endpoint of graft loss or death (odds ratio = 3.4 [3.0-399.5]; P = .004). In female patients, low SMI was not associated with length of hospitalization or adverse outcomes after transplantation.

CONCLUSION

SMI is an independent marker of morbidity and mortality after kidney transplantation in older men and could help thereby nephrologists better select aging candidates for kidney transplantation with a view to improving post-transplant outcomes.

Muscle mass assessment in renal disease: the role of imaging techniques

Muscle wasting is a frequent finding in patients with chronic kidney disease (CKD), especially in those with end-stage kidney disease (ESKD) on chronic dialysis. Muscle wasting in CKD is a main feature of malnutrition, and results principally from a vast array of metabolic derangements typical of the syndrome, that converge in determining reduced protein synthesis and accelerated protein catabolism. In this clinical setting, muscle wasting is also frequently associated with disability, frailty, infections, depression, worsened quality of life and increased mortality. On these grounds, the evaluation of nutritional status is crucial for an adequate management of renal patients, and consists of a comprehensive assessment allowing for the identification of malnourished patients and patients at nutritional risk. It is based essentially on the assessment of the extent and trend of body weight loss, as well as of spontaneous dietary intake. Another key component of this evaluation is the determination of body composition, which, depending on the selected method among several ones available, can identify accurately patients with decreased muscle mass. The choice will depend on the availability and ease of application of a specific technique in clinical practice based on local experience, staff resources and good repeatability over time. Surrogate methods, such as anthropometry and bioimpedance analysis (BIA), represent the most readily available techniques. Other methods based on imaging modalities [dual-energy X-ray absorptiometry (DXA), magnetic resonance imaging (MRI), and whole body computed tomography (CT)] are considered to be the "gold standard" reference methods for muscle mass evaluation, but their use is mainly confined to research purposes. New imaging modalities, such as segmental CT scan and muscle ultrasound have been proposed in recent years. Particularly, ultrasound is a promising technique in this field, as it is commonly available for bedside evaluation of renal patients in nephrology wards. However, more data are needed before a routine use of ultrasound for muscle mass evaluation can be recommended in clinical practice.

Novel Insights into the Pathogenesis of Spinal Sarcopenia and Related Therapeutic Approaches: A Narrative Review

Spinal sarcopenia is a complex and multifactorial disorder associated with a loss of strength, increased frailty, and increased risks of fractures and falls. In addition, spinal sarcopenia has been associated with lumbar spine disorders and osteoporosis, which renders making decisions on treatment modalities difficult. Patients with spinal sarcopenia typically exhibit lower cumulative survival, a higher risk of in-hospital complications, prolonged hospital stays, higher postoperative costs, and higher rates of blood transfusion after thoracolumbar spine surgery. Several studies have focused on the relationships between spinal sarcopenia, appendicular muscle mass, and bone-related problems-such as osteoporotic fractures and low bone mineral density-and malnutrition and vitamin D deficiency. Although several techniques are available for measuring sarcopenia, each of them has its advantages and shortcomings. For treating spinal sarcopenia, nutrition, physical therapy, and medication have been proven to be effective; regenerative therapeutic options seem to be promising owing to their repair and regeneration potential. Therefore, in this narrative review, we summarize the characteristics, detection methodologies, and treatment options for spinal sarcopenia, as well as its role in spinal disorders.

Paediatric reference values for total psoas muscle area

BACKGROUND

Sarcopenia, the unintentional loss of skeletal muscle mass, is associated with poor outcomes in adult patient populations. In adults, sarcopenia is often ascertained by cross-sectional imaging of the psoas muscle area (PMA). Although children with chronic medical illnesses may be at increased risk for muscle loss because of nutritional deficiencies, physical deconditioning, endocrine anomalies, and systemic inflammation, consistent quantitative definitions for sarcopenia in children are lacking. We aimed to generate paediatric reference values for PMA at two intervertebral lumbar levels, L3-4 and L4-5.

METHODS

In this cross-sectional study, we analysed abdominal computed tomography scans of consecutive children presenting to the emergency department. Participants were children 1-16 years who required abdominal cross-sectional imaging after paediatric trauma between January 1, 2005 and December 31, 2015 in a large Canadian quaternary care centre. Children with a documented chronic medical illness or an acute spinal trauma at presentation were excluded. Total PMA (tPMA) at levels L3-4 and L4-5 were measured in square millimetres (mm² ) as the sum of left and right PMA. Age-specific and sex-specific tPMA percentile curves were modelled using quantile regression.

RESULTS

Computed tomography images from 779 children were included. Values of tPMA at L4-5 were significantly larger than at L3-4 at all ages, but their correlation was high for both girls (r = 0.95) and boys (r = 0.98). Amongst girls, tPMA 50th percentile values ranged from 365 to 2336 mm² at L3-4 and from 447 to 2704 mm² for L4-5. Amongst boys, 50th percentile values for tPMA ranged between 394 and 3050 mm² at L3-4 and from 498 to 3513 mm² at L4-5. Intraclass correlation coefficients were excellent at L3-4 (0.97, 95% CI 0.94 to 0.981) and L4-5 (0.99, 95% CI 0.986 to 0.995). Weight and tPMA were correlated, stratified by sex for boys (L3-4 r = 0.90; L4-5 r = 0.90) and for girls (L3-4 r = 0.87; L4-5 r = 0.87). An online application was subsequently developed to easily calculate age-specific and sex-specific z-scores and percentiles.

CONCLUSIONS

We provide novel paediatric age-specific and sex-specific growth curves for tPMA at intervertebral L3-4 and L4-5 levels for children between the ages of 1-16 years. Together with an online tool (https://ahrc-apps.shinyapps.io/sarcopenia/), these tPMA curves should serve as a reference enabling earlier identification and targeted intervention of sarcopenia in children with chronic medical conditions.

Recent Issues on Body Composition Imaging for Sarcopenia Evaluation

Recently, sarcopenia has garnered renewed interest. Sarcopenia is a disease characterized by decreased skeletal muscle mass and strength/function, which can impair the quality of life and increase physical disability, adverse metabolic effects, and mortality. Imaging tools for evaluating and diagnosing sarcopenia have developed rapidly. Radiologists should be aware of sarcopenia and its clinical implications. We review current knowledge about sarcopenia, its pathophysiological impact, and advantages and disadvantages of methods for evaluation of sarcopenia focusing on body composition imaging modalities such as whole-body dual-energy X-ray absorptiometry, CT, and MRI. Controversial issues are discussed, including the lack of consensus and standardization of the disease definition, imaging modality, measurement methods, and diagnostic cutoff points.

MRI-Derived Biomarkers Related to Sarcopenia: A Systematic Review

BACKGROUND

MRI allows quantitatively assessing muscle quantity and quality.

PURPOSE

To summarize the role of MRI as a noninvasive technique for the identification of in vivo surrogate biomarker of sarcopenia.

STUDY TYPE

Systematic review.

POPULATION

In April 2019, a systematic literature search (Medline/EMBASE) was performed to identify articles on the topic at issue.

FIELD STRENGTH/SEQUENCE

No field strength or sequence restrictions.

ASSESSMENT

After a literature search, study design, aim, sample size, demographics, magnetic field strength, imaged body region, MRI sequences, and imaging biomarker were extracted.

STATISTICAL TESTS

Data are presented as frequencies and percentages.

RESULTS

From 69 records identified through search query, 18 articles matched the inclusion criteria. All articles were published from 2012 and had a mainly prospective design (14/18, 78%). Sample size ranged from 9 to 284 subjects, for a total of 1706 enrolled subjects. Healthy subjects were enrolled or retrospectively selected in 8/18 (44%) articles, corresponding to 658 (39%) healthy subjects. Magnetic field strength was 1.5 or 3T in 14/18 (78%) studies. The most analyzed body regions were the thigh (7/18, 39%) and the trunk (6/18, 33%). Stratifying studies according to their aim, 13/18 (72%) studies focused on muscle quality and quantity, 3/18 (17%) studies on outcome prediction, and 2/18 articles (11%) addressed both aims. A wide set of MRI biomarkers have been proposed. Muscle cross-sectional area was the most used for muscle quantity estimation, while quantitative biomarkers of muscle fat content or fiber architecture were proposed to assess muscle quality.

DATA CONCLUSION

The proposed biomarkers were assessed using different MRI sequences for different body regions in different subjects/patient cohorts, pointing out a lack of standardization on this topic. Future studies should test and compare the performance of proposed MRI biomarkers for sarcopenia characterization and quantification using a standardized experimental setup.

LEVEL OF EVIDENCE

1 Technical Efficacy Stage: 2 J. Magn. Reson. Imaging 2020;51:1117-1127.

Psoas cross-sectional area as a predictor of mortality and a diagnostic tool for sarcopenia in hip fracture patients

This study aimed to determine: (1) the association between psoas cross-sectional area (PCA) and mortality in hip fracture patients, and (2) the usefulness of PCA as a diagnostic tool for sarcopenia. A total of 373 female and 121 male hip fracture patients aged 50 years or more who had surgical repair of their hip fracture between 2011 and 2017 were analyzed. PCA was measured at L4-L5 disc level using CT. PCA of gender-specific 20th percentile determined from this study cohort was used as a cutoff value. The effect of decreased PCA on mortality was analyzed. The association between PCA and appendicular lean mass (ALM) or/and grip strength was analyzed. In survival time of both genders, a significant difference was found between patients with the lowest quintile and upper 4 quintiles (p < 0.001 for females, p = 0.040 for males). The lowest quintile of PCA was associated with mortality, with hazard ratio (HR) of 2.33 (95% CI 1.44-3.47, p < 0.001) in females and 2.01 (95% CI 1.01-3.98, p = 0.046) in males. After adjustment of age, American Society of Anesthesiologists classification, body mass index, dementia, and a grip strength, the lowest quintile of PCA was significantly associated with mortality only in females, with HR of 1.76 (95% CI 1.05-2.70, p = 0.017). A moderate association between PCA and ALM was found in both genders (r = 0.358 for females, r = 0.455 for males). In conclusion, measurement of PCA has potential as a prognostic predictor and diagnostic tool for sarcopenia.

Sarcopenia predicts 90-day mortality in elderly patients undergoing emergency abdominal surgery

PURPOSE

Image-based measurement of sarcopenia is an established predictor of a decreased outcome for a large variety of surgical procedures. Sarcopenia in elderly patients undergoing emergency abdominal surgery has not been well studied. This study aims to investigate the association between the total psoas area (TPA) and postoperative mortality after 90 days in a group of elderly emergency laparotomy patients.

METHODS

We retrospectively reviewed the emergency CT-scans of 150 elderly patients from a consecutive cohort undergoing emergency abdominal surgery at our surgical center. TPA was measured manually at the level of L3 and indexed to patient height. Sarcopenia was defined as having a TPA index below the first quartile for gender in the cohort. Other collected variables were age, vital status/date of death, ASA-score, surgical procedure, and WHO performance score.

RESULTS

Overall 90-day mortality was 42.7%. Sarcopenic patients had a higher 90-day mortality (60.5%) than non-sarcopenic patients (36.6%), corresponding to an odds ratio of 2.66 (95% confidence interval 1.2-5.7, p = 0.01). Sarcopenic patients had an increased mortality compared with non-sarcopenic patients (p = 0.0009, Log-rank test), with a clear separation of the two groups within 30 days postoperatively. In a multivariate logistic regression model, with age, ASA-score, and WHO performance score as covariates, sarcopenia was independently associated with 90-day mortality.

CONCLUSION

Manual measurement of TPA on an abdominal CT-scan is a relevant risk factor for postoperative mortality in elderly patients undergoing high-risk emergency abdominal surgery. Incorporation of sarcopenia in postoperative risk-prediction models in emergency abdominal surgery should be considered.