The psoas muscle index as a predictor of long-term survival after cardiac surgery for hemodialysis-dependent patients

Normalized total psoas area predicts early postoperative mobility and perioperative adverse events after adult spinal deformity surgery

BACKGROUND CONTEXT

Poor muscle health has been shown to predict poor perioperative outcomes following adult spinal deformity (ASD) surgery. Currently, there is limited data concerning the correlation between muscle health and recovery among patients undergoing ASD surgery.

PURPOSE

To determine the relationship between normalized total psoas area (NTPA), postoperative mobility and adverse events (AEs) among patients undergoing ASD surgery.

STUDY DESIGN

Retrospective cohort study.

PATIENT SAMPLE

A retrospective analysis was performed at a single institution between January 2014 and December 2023 of patients undergoing ASD surgery by 10 board certified fellowship-trained orthopaedic spine surgeons.

OUTCOME MEASURES

Primary outcome measures were postoperative ambulation distance on postoperative day (POD) 1, 2, 3, and 4 as well as perioperative adverse events including postoperative anemia requiring transfusion, ileus, urinary retention wound complication including dehiscence and infection, delirium, atelectasis, urinary tract infection (UTI), deep vein thrombosis (DVT), and epidural hematoma. Secondary outcome measures were 30-day reoperation rates, 30-day readmission rates, and postoperative length of stay (LOS).

METHODS

Patients that underwent ASD surgery at a single center (2014-2023) were included in the study. NTPA was analyzed at the L3 and L4 midvertebral body on preoperative magnetic resonance imaging (MRI). Receiver operating characteristic (ROC) curve analysis was used to determine gender-specific NTPA cut-off values for predicting perioperative AEs. Patients were categorized as having a low NTPA if both L3 and L4 NTPA were below the cut-off values. Multivariate logistic regression was conducted to identify confounding predictors of perioperative AEs.

RESULTS

279 patients (102 males, 177 females, mean age 61.2±15.2 years) were included. ROC curve analysis demonstrated L3 NTPA <805 mm2/m2 for males and <505 mm2/m2 for females and L4 NTPA <912 mm2/m2 for males and <714 mm2/m2 for females as cut-off values predicting perioperative AEs. 103 patients (36.9%, 42 males, 61 females) were below these cut-off values and were in the low NTPA cohort. The remaining 176 patients (63.1%, 60 males, 116 females) were in the normal NTPA cohort. The low NTPA group had a higher overall perioperative AEs (70.9% vs 39.2%, p<.001), and lower ambulation distances on postoperative day 1 and 2 compared to the normal NTPA group (p=.021, p=.028, respectively). On multivariate analysis, there were no other predictors of perioperative AEs.

CONCLUSIONS

Low L3 and L4 NTPA is associated with lower early postoperative mobility and higher rates of perioperative AEs among patients undergoing ASD surgery. These findings stress the importance of muscle health in recovery after ASD surgery.

Psoas muscle gauge and adverse clinical outcomes in patients on hemodialysis

BACKGROUND

The relationship between the psoas muscle gauge (PMG), a combined sarcopenia indicator obtained from psoas muscle index (PMI) and psoas muscle density (PMD), and adverse clinical outcomes in patients on hemodialysis remains unclear. We examined whether psoas muscle gauge could predict all-cause mortality and new cardiovascular events more accurately than psoas muscle index in these patients.

METHODS

We retrospectively included 217 hemodialysis patients who underwent abdominal computed tomography. We calculated the psoas muscle gauge (arbitrary unit [AU]) at the fourth lumbar vertebra level as follows: PMI (cm2/m2) × PMD (Hounsfield units). We categorized the patients into higher and lower psoas muscle gauge groups based on sex-specific cutoffs obtained from the young Asian population. The outcomes were death and new cardiovascular events.

RESULTS

The psoas muscle gauge cutoffs were set at 231.1 and 328.8 AU in women and men, respectively. Eighty-five deaths and 95 new cardiovascular events occurred during the follow-up period of 4.4 (2.4-7.3) years. The 5-year survival rates were 59.2% and 94.9% in the lower and higher psoas muscle gauge groups, respectively (p < 0.0001). Moreover, after adjusting for sex and age, history of cardiovascular disease, C-reactive protein, modified creatinine index, and geriatric nutritional risk index, lower psoas muscle gauge was independently associated with increased all-cause death and new cardiovascular events (adjusted hazard ratio (aHR) 7.65; 95% confidence interval (CI) 2.37-24.66 and aHR 2.98; 95% CI 1.54-5.75, respectively). The concordance index (C-index) for predicting all-cause mortality and new cardiovascular events significantly improved when either psoas muscle index or psoas muscle gauge were added to the baseline risk model. Additionally, the C-index of the psoas muscle gauge-added model was significantly higher than that of the psoas muscle index-added model (0.815 vs. 0.784, p = 0.026) only when predicting all-cause mortality.

CONCLUSIONS

Psoas muscle gauge accurately predicted the risk of all-cause mortality and new cardiovascular events in patients undergoing hemodialysis. For predicting all-cause mortality, psoas muscle gauge may be recommended compared to psoas muscle index.

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.

Pre-operative psoas muscle index, a surrogate for sarcopenia; as a predictor of post-esophagectomy complications

BACKGROUND

Esophagectomy is the standard of care for curative esophageal cancer. However, it is associated with significant morbidity and mortality. Esophageal cancer is known to negatively affect the nutritional status of patients and many manifest cancer sarcopenia. At present, measures of sarcopenia involve complex and often subjective measurements. We assess whether the Psoas Muscle Index (PMI); an inexpensive, simple, validated method used to diagnose sarcopenia, can be used to predict adverse outcomes in patients after curative esophagectomy.

METHODS

Multi-centre, retrospective cohort between 2010-2020, involving all consecutive patients undergoing curative esophagectomy for esophageal cancer in University Malaya Medical Centre, Sungai Buloh Hospital, and Sultanah Aminah Hospital. The cut-off value differentiating low and normal PMI is defined as 443mm2/m2 in males and 326326 mm2/m2 in females. Complications were recorded using the Clavien-Dindo Scale.

RESULTS

There was no statistical correlation between PMI and major post-esophagectomy complications (p-value: 0.495). However, complication profile was different, and patients with low PMIs had higher 30-day mortality (21.7%) when compared with patients with normal PMI (8.1%) (p-value: 0.048).

CONCLUSIONS

Although PMI did not significantly predict post-esophagectomy complications, low PMI correlates with higher 30-day mortality, reflecting a lower tolerance for complications among these patients. PMI is a useful, inexpensive tool to identify sarcopenia and aids the patient selection process. This alerts healthcare professionals to institute intensive physiotherapy and nutritional optimization prior to esophagectomy.

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.

Intramuscular and abdominal fat measured by computed tomography and mortality of hemodialysis patients

BACKGROUND

In hemodialysis patients, high body mass index is associated with low mortality while abdominal obesity relates to increased mortality. We aimed to investigate the association between muscle mass, intramuscular fat and abdominal fat measured by abdominal computed tomography (CT), and mortality in this patients population.

METHODS

This two-center retrospective cohort study included hemodialysis patients who underwent abdominal CT between January 2013 and December 2018. Skeletal muscle mass index (SMI), muscle radiation attenuation (MRA) as an index of intramuscular fat, and visceral fat to subcutaneous fat ratio (VSR) were calculated using CT images at the third lumbar vertebral level. Multivariate Cox proportional hazards model was used to determine the independent predictors of all-cause, cardiovascular and non-cardiovascular mortalities.

RESULTS

The study included 344 patients (median age 71.0 years; female 33.7%), among whom 145 died during a median follow-up of 4.9 years-46 and 99 from cardiovascular and non-cardiovascular causes, respectively. Lower MRA [hazard ratio (HR) 0.71, 95% confidence interval (CI) 0.58-0.87, P = .001] and higher VSR (HR 1.17, 95% CI 1.01-1.37, P = .04) were independently associated with higher all-cause mortality but not with lower SMI (HR 0.87, 95% CI 0.68-1.11, P = .26). Lower MRA (HR 0.51, 95% CI 0.35-0.73, P < .001) and higher VSR (HR 1.29, 95% CI 1.09-1.54, P = .003) were also associated with cardiovascular and non-cardiovascular mortality, respectively.

CONCLUSIONS

Intramuscular fat and abdominal fat as measured using abdominal CT in hemodialysis patients are stronger independent predictors of mortality than muscle mass.

Automated evaluation of masseter muscle volume: deep learning prognostic approach in oral cancer

BACKGROUND

Sarcopenia has been identified as a potential negative prognostic factor in cancer patients. In this study, our objective was to investigate the relationship between the assessment method for sarcopenia using the masseter muscle volume measured on computed tomography (CT) images and the life expectancy of patients with oral cancer. We also developed a learning model using deep learning to automatically extract the masseter muscle volume and investigated its association with the life expectancy of oral cancer patients.

METHODS

To develop the learning model for masseter muscle volume, we used manually extracted data from CT images of 277 patients. We established the association between manually extracted masseter muscle volume and the life expectancy of oral cancer patients. Additionally, we compared the correlation between the groups of manual and automatic extraction in the masseter muscle volume learning model.

RESULTS

Our findings revealed a significant association between manually extracted masseter muscle volume on CT images and the life expectancy of patients with oral cancer. Notably, the manual and automatic extraction groups in the masseter muscle volume learning model showed a high correlation. Furthermore, the masseter muscle volume automatically extracted using the developed learning model exhibited a strong association with life expectancy.

CONCLUSIONS

The sarcopenia assessment method is useful for predicting the life expectancy of patients with oral cancer. In the future, it is crucial to validate and analyze various factors within the oral surgery field, extending beyond cancer patients.

Impact of sarcopenia on outcomes in surgical patients: a systematic review and meta-analysis

BACKGROUND

Surgeons have historically used age as a preoperative predictor of postoperative outcomes. Sarcopenia, the loss of skeletal muscle mass due to disease or biological age, has been proposed as a more accurate risk predictor. The prognostic value of sarcopenia assessment in surgical patients remains poorly understood. Therefore, the authors aimed to synthesize the available literature and investigate the impact of sarcopenia on perioperative and postoperative outcomes across all surgical specialties.

METHODS

The authors systematically assessed the prognostic value of sarcopenia on postoperative outcomes by conducting a systematic review and meta-analysis according to Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) guidelines, searching the PubMed/MEDLINE and EMBASE databases from inception to 1st October 2022. Their primary outcomes were complication occurrence, mortality, length of operation and hospital stay, discharge to home, and postdischarge survival rate at 1, 3, and 5 years. Subgroup analysis was performed by stratifying complications according to the Clavien-Dindo classification system. Sensitivity analysis was performed by focusing on studies with an oncological, cardiovascular, emergency, or transplant surgery population and on those of higher quality or prospective study design.

RESULTS

A total of 294 studies comprising 97 643 patients, of which 33 070 had sarcopenia, were included in our analysis. Sarcopenia was associated with significantly poorer postoperative outcomes, including greater mortality, complication occurrence, length of hospital stay, and lower rates of discharge to home (all P <0.00001). A significantly lower survival rate in patients with sarcopenia was noted at 1, 3, and 5 years (all P <0.00001) after surgery. Subgroup analysis confirmed higher rates of complications and mortality in oncological (both P <0.00001), cardiovascular (both P <0.00001), and emergency ( P =0.03 and P =0.04, respectively) patients with sarcopenia. In the transplant surgery cohort, mortality was significantly higher in patients with sarcopenia ( P <0.00001). Among all patients undergoing surgery for inflammatory bowel disease, the frequency of complications was significantly increased among sarcopenic patients ( P =0.007). Sensitivity analysis based on higher quality studies and prospective studies showed that sarcopenia remained a significant predictor of mortality and complication occurrence (all P <0.00001).

CONCLUSION

Sarcopenia is a significant predictor of poorer outcomes in surgical patients. Preoperative assessment of sarcopenia can help surgeons identify patients at risk, critically balance eligibility, and refine perioperative management. Large-scale studies are required to further validate the importance of sarcopenia as a prognostic indicator of perioperative risk, especially in surgical subspecialties.

Impact of sarcopenia on long-term survival after cardiac surgery for end-stage renal disease patients

BACKGROUND

The long-term mortality of end-stage renal disease (ESRD) patients is still unsatisfactory. Therefore, long-term risk assessments in ESRD patients undergoing cardiac surgery are needed. Recently, sarcopenia is major concern in cardiac surgery because of its association with poor long-term survival. However, the impact of sarcopenia on the long-term survival of ESRD patients undergoing cardiac surgery is not well understood.

METHODS

Eighty-two ESRD patients who underwent elective cardiac surgery were enrolled. Sarcopenia was identified based on noncontrast abdominal computed tomography. The impact of preoperative and intraoperative factors on long-term survival was investigated.

RESULTS

Forty-three patients (52%) were diagnosed with sarcopenia. The in-hospital mortality rate was 4.9%. The 5-year overall survival rate was 48%. The multivariate analyses revealed that STS score ≥ 4 (odds ratio, 6.0; confidence interval, 2.5-14.7; p < 0.01) and presence of sarcopenia (odds ratio, 2.4; confidence interval, 1.3-4.5; p  =  0.03) were independent risk factors for overall survival. The 5-year survival rates of low-risk (Society of Thoracic Surgeons score of < 4) patients without sarcopenia, low-risk with sarcopenia, more than intermediate-risk (Society of Thoracic Surgeons score of ≥ 4) without sarcopenia, and more than intermediate-risk with sarcopenia groups were 80%, 51%, 50%, and 26%, respectively.

CONCLUSIONS

Among the ESRD patients, the low risk without sarcopenia group showed an excellent long-term survival, in contrast to more than intermediate-risk patients with sarcopenia, who can expect poor long-term survival. Preoperative assessment of sarcopenia in addition to the surgical risk score can be useful in developing a therapeutic strategy.

Psoas muscle quantified muscle status and long-term mortality after cardiovascular interventions

RESULTS

In the meta-analysis, psoas muscle measurements were significantly associated with mortality among men (p < 0.05), with high heterogeneity in the associations across all cohorts. There was very little difference in the association between PMA and PMD and mortality (HR 0.83, 95% CI 0.69-0.99, p = 0.002; HR 0.85, 95% CI 0.77-0.94, p = 0.041 for one SD increase in PMA and PMD in the random effects model). Combining PMA and PMD into one composite variable by multiplying their values together showed the most robust association in terms of the magnitude of the effect size in men (HR, 0.77; 95% CI 0.73-0.87, p < 0.001). Indexing PMA to body size did not result in any significant differences in this association. Among women, psoas muscle measurements were not associated with long-term mortality in this meta-analysis.

CONCLUSIONS

Different psoas muscle measurements were significantly and very similarly associated with mortality among men but not among women. No single measurement stands out, although combining PMA and PMD seems to be a slightly stronger estimate in terms of effect size and should be considered in further studies.

Sarcopenia Adversely Affects Outcomes following Cardiac Surgery: A Systematic Review and Meta-Analysis

BACKGROUND

Sarcopenia is a degenerative condition characterised by the loss of skeletal muscle mass and strength. Its impact on cardiac surgery outcomes remains poorly investigated. This meta-analysis aims to provide a comprehensive synthesis of the available evidence to determine the effect of sarcopenia on cardiac surgery outcomes.

METHODS

A systematic review and meta-analysis followed PRISMA guidelines from inception to April 2023 in EMBASE, MEDLINE, Cochrane database, and Google Scholar. Twelve studies involving 2717 patients undergoing cardiac surgery were included. Primary outcomes were early and late mortality; secondary outcomes included surgical time, infection rates, and functional outcomes. Statistical analyses were performed using appropriate methods.

RESULTS

Sarcopenic patients (906 patients) had a significantly higher risk of early mortality (OR: 2.40, 95% CI: 1.44 to 3.99, p = 0.0007) and late mortality (OR: 2.65, 95% CI: 1.57 to 4.48, p = 0.0003) compared to non-sarcopenic patients (1811 patients). There were no significant differences in overall surgical time or infection rates. However, sarcopenic patients had longer ICU stays, higher rates of renal dialysis, care home discharge, and longer intubation times.

CONCLUSION

Sarcopenia significantly increases the risk of early and late mortality following cardiac surgery, and sarcopenic patients also experience poorer functional outcomes.

Sarcopenia in Men With Bone-Predominant Metastatic Castration-Resistant Prostate Cancer Undergoing Ra-223 Therapy

INTRODUCTION

Osteosarcopenia is the progressive loss of musculoskeletal structure and functionality, contributing to disability and mortality. Despite complex interactions between bone and muscle, osteosarcopenia prevention and treatment in men with metastatic castration-resistant prostate cancer (mCRPC) focuses predominantly on bone health. It is unknown whether Radium-223 (Ra-223) therapy affects sarcopenia.

METHODS

We identified 52 patients with mCRPC who had received Ra-223 and had a baseline plus ≥1 follow-up abdominopelvic CT scan. The total contour area (TCA) and averaged Hounsfield units (HU) of the left and right psoas muscles were obtained at the inferior L3 endplate, and the psoas muscle index (PMI) was calculated therefrom. Intrapatient musculoskeletal changes were analyzed across various time points.

RESULTS

TCA and PMI gradually declined over the study period (P = .002, P = .003, respectively), but Ra-223 therapy did not accelerate sarcopenia, nor the decline of HU compared to the pre-Ra-223 period. The median overall survival of patients with baseline sarcopenia was numerically worse (14.93 vs. 23.23 months, HR 0.612, P = .198).

CONCLUSIONS

Ra-223 does not accelerate sarcopenia. Thus, worsening muscle parameters in men with mCRPC undergoing Ra-223 therapy are attributable to other factors. Further research is needed to determine whether baseline sarcopenia predicts poor overall survival in such patients.

Cutoff Value of Psoas Muscle Area as Reduced Muscle Mass and Its Association with Acute Pancreatitis in China

Objective

The Global Leadership Initiative on Malnutrition (GLIM) has proposed criteria for the diagnosis of malnutrition, one of which is reduced muscle mass. Computed tomography (CT) assessment of psoas muscle area (PMA) has been used to estimate muscle mass in patients, including those with acute pancreatitis (AP). The present study aimed to define the cutoff value of PMA indicative of reduced muscle mass in patients with AP and to assess the impact of reduced muscle mass on the severity and early complications of AP.

Methods

Clinical data of 269 patients with AP were analyzed retrospectively. The severity of AP was determined according to the revised Atlanta classification. PMA was evaluated by CT and used to calculate the psoas muscle index (PMI). Cutoff values for reduced muscle mass were calculated and validated. Logistic regression analysis was performed to assess the relationship between PMA and the severity of AP.

Results

PMA was a better indicator of reduced muscle mass than PMI, with cutoff values of 11.50 cm² for men and 8.22 cm² for women. Rates of local complications, splenic vein thrombosis, and organ failure were significantly higher in AP patients with low than high PMA (all p < 0.05). PMA showed good ability to predict splenic vein thrombosis in women, with an area under the receiver operating characteristic curve of 0.848 (95% confidence interval 0.768-0.909, sensitivity 100%, specificity 83.64%). Multivariate logistic regression revealed that PMA was an independent risk factor for moderately severe plus severe AP (odds ratio 5.639, p = 0.001) and severe AP (odds ratio 3.995, p = 0.038).

Conclusion

PMA is a good predictor of the severity and complications of AP. The PMA cutoff value is a good indicator of reduced muscle mass.

The association between paraspinal muscle parameters and vertebral pedicle microstructure in patients undergoing lumbar fusion surgery

PURPOSE

Lumbar fusion surgery has become a standard procedure in spine surgery and commonly includes the posterior placement of pedicle screws. Bone quality is a crucial factor that affects pedicle screw purchase. However, the relationship between paraspinal muscles and the bone quality of the pedicle is unknown. The aim of the study was to determine the relationship between paraspinal muscles and the ex vivo bony microstructure of the lumbar pedicle.

METHODS

Prospectively, collected data of patients undergoing posterior lumbar fusion for degenerative spinal conditions was analyzed. Pre-operative lumbar magnetic resonance imaging (MRI) scans were evaluated for a quantitative assessment of the cross-sectional area (CSA), functional cross-sectional area (fCSA), and the proportion of intramuscular fat (FI) for the psoas muscle and the posterior paraspinal muscles (PPM) at L4. Intra-operative bone biopsies of the lumbar pedicle were obtained and analyzed with microcomputed tomography (µCT) scans. The following cortical (Cort) and trabecular (Trab) bone parameters were assessed: bone volume fraction (BV/TV), trabecular number (Tb.N), trabecular thickness (Tb.Th), connectivity density (CD), bone-specific surface (BS/BV), apparent density (AD), and tissue mineral density (TMD).

RESULTS

A total of 26 patients with a mean age of 59.1 years and a mean BMI of 29.8 kg/m2 were analyzed. fCSAPPM showed significant positive correlations with BV/TVTrab (ρ = 0.610; p < 0.001), CDTrab (ρ = 0.679; p < 0.001), Tb.NTrab (ρ = 0.522; p = 0.006), Tb.ThTrab (ρ = 0.415; p = 0.035), and ADTrab (ρ = 0.514; p = 0.007). Cortical bone parameters also demonstrated a significant positive correlation with fCSAPPM (BV/TVCort: ρ = 0.584; p = 0.002; ADCort: ρ = 0.519; p = 0.007). FIPsoas was negatively correlated with TMDCort (ρ =  - 0.622; p < 0.001).

CONCLUSION

This study highlights the close interactions between the bone microstructure of the lumbar pedicle and the paraspinal muscle morphology. These findings give us further insights into the interaction between the lumbar pedicle microstructure and paraspinal muscles.

The effect of age on psoas and paraspinal muscle morphology in patients undergoing posterior lumbar fusion surgery

PURPOSE

The aim of this study was to determine the effect of age on the psoas and posterior paraspinal muscles (PPM; multifidus muscle and erector spinae) and to evaluate potential sex-related differences.

METHODS

MRI-based quantitative assessments of the cross-sectional area (CSA), the functional cross-sectional area (fCSA), the fat area (FAT) and the proportion of intramuscular fat (FI) were conducted on patients undergoing lumbar fusion surgery between 2014 and 2021. The regions of interest were the psoas muscle and the PPM at the superior endplate of L4. The left and right sides of the muscle groups were summarized and normalized by the patient's height (cm2/m2). The relationships between age and muscular parameters were analyzed stratified by sex.

RESULTS

A total of 195 patients (57.9%female) with a median age of 64.2 years and a body mass index of 28.3 kg/m2 were analyzed. The CSAPsoas was 7.7 cm2/m2 and differed significantly between females and males (p < 0.001); likewise, the fCSAPsoas differed significantly between the sexes. The CSAPPM was 18.8 cm2/m2 with no sex-specific differences. Significant differences were found in the FIPPM (males: 41.1% vs. females: 47.9%; p < 0.001), but not in the FIPsoas (males: 3.7% vs. females: 4.5%; p = 0.276). Considering the effect of age on FI, a significant positive correlation was observed for the PPMs for both sexes. Only in women, there was a negative correlation between age and CSAPsoas (ρ =  - 0.248; p = 0.008), FATPsoas (ρ =  - 0.421; p < 0.001) and FIPsoas (ρ =  - 0.371; p < 0.001).

CONCLUSION

This study demonstrated sex-specific differences in spinal muscle morphology in relation to patient age. With increasing age there was a decrease in FIPsoas in women only, unlike in the PPMs in which there was increased FI that was significantly higher in women compared to men.

Psoas muscle index and psoas muscle density as predictors of mortality in patients undergoing hemodialysis

This study aimed to investigate the associations of computed tomography (CT)-measured psoas muscle index (PMI: psoas muscle area normalized by height) and psoas muscle density (PMD: average of bilateral psoas muscle CT values [Hounsfield unit (HU)]) with mortality in patients undergoing hemodialysis. We included 188 hemodialysis patients who underwent abdominal CT. PMI and PMD were measured at the third lumbar vertebral level. We found that PMI and PMD were independently associated with the geriatric nutritional risk index and log C-reactive protein, respectively. The optimal cut-off values of PMI and PMD for men and women were 3.39 cm²/m² and 41.6 HU, and 2.13 cm²/m² and 37.5 HU, respectively. During follow-up (median 3.5 years), 69 patients died. Lower PMI and lower PMD were independently associated with an increased risk of all-cause mortality [adjusted hazard ratio (aHR) 2.05, 95% confidence interval (CI) 1.14–3.68; aHR 3.67, 95% CI 2.04–6.60), respectively]. The aHR for lower PMI and lower PMD vs. higher PMI and higher PMD was 5.34 (95% CI 2.38–11.97). The addition of PMI and PMD to the risk model significantly improved C-index from 0.775 to 0.893 (p < 0.00001). The combination of PMI and PMD may improve mortality prediction in patients undergoing hemodialysis.

Impact of Body Mass Index and Sarcopenia on Short- and Long-Term Outcomes After Esophageal Cancer Surgery: An Observational Study

BACKGROUND

The effects of specific body mass index (BMI) category and sarcopenia within each BMI category on outcomes in patients undergoing esophageal surgery with esophageal squamous cell carcinoma have not been thoroughly examined.

METHODS

This study included 1141 patients. Sarcopenia was determined with a total psoas muscle cross-sectional area at the level of the third lumbar vertebra in computed tomography. The outcomes were long-term survival, including overall survival (OS) and recurrence-free survival (RFS), and postoperative complications.

RESULTS

The overweight and no sarcopenia group was considered as the reference. After adjusting covariates, the underweight and the normal weight and sarcopenia groups both showed worse OS (underweight group: hazard ratio [HR] 2.04, 95% confidence interval [CI] 1.33-3.13, p = 0.001; normal weight and sarcopenia group: HR 1.93, 95% CI 1.39-2.69, p < 0.001) and worse RFS (underweight group: HR 1.78, 95% CI 1.19-2.67, p = 0.005; normal weight and sarcopenia group: HR 1.70, 95% CI 1.25-2.30, p = 0.001). In addition, the underweight group (odds ratio [OR] 4.74, 95% CI 2.05-10.96, p < 0.001), the normal weight and sarcopenia group (OR 3.26, 95% CI 1.60-6.62, p = 0.001), the overweight and sarcopenia group (OR 2.54, 95% CI 1.14-5.68, p = 0.023), and the obese and no sarcopenia group (OR 2.44, 95% CI 1.14-5.22, p = 0.021) were at significantly higher risk of postoperative 30-day composite complications.

CONCLUSIONS

Compared with the overweight and no sarcopenia group, the underweight and the normal weight and sarcopenia groups were associated with worse short- and long-term outcomes.

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.

The impact of muscle mass loss and deteriorating physical function on prognosis in patients receiving hemodialysis

Muscle mass loss and worsening physical function are crucial issues in patients receiving hemodialysis (HD). However, few studies have investigated the association between temporal changes in muscle mass and physical function in a large number of HD patients. We examined 286 patients receiving HD (males, 58%; age, 66.8 ± 13.0 years) at a single center, and calculated the percent changes in psoas muscle mass index (%PMI) using computed tomography over two screenings, once per year (July 2011–June 2013). Physical function was evaluated using the Eastern Cooperative Oncology Group Performance Status (ECOG-PS) (range 0–4). The observation period was from July 2012 to June 2021. The median %PMI was -9.5%, and those with the lowest quartile of %PMI (< −20.5%) showed a significantly poor prognosis compared with other patients (p < 0.001). Multivariable logistic regression analysis revealed that these patients tended to have decreased physical function (ECOG-PS 2–4) [odds ratio (OR): 2.46, p < 0.001] and albumin levels (OR: 0.22, p = 0.007). Multiple-factor-adjusted Cox regression analyses showed that %PMI (hazard ratio: 0.99, p = 0.004) and each ECOG-PS stage (1–4 vs. 0) (p < 0.01) were associated with mortality. Augmenting physical activities in daily life and serum albumin levels should be considered to maintain muscle mass and improve the prognosis of patients receiving HD.

Usefulness of computed tomography-measured psoas muscle thickness per height for predicting mortality in patients undergoing hemodialysis

Computed tomography (CT)-measured psoas muscle thickness standardized for height (PMTH) has emerged as a promising predictor of mortality. The study aimed to investigate whether PMTH could accurately predict mortality in patients undergoing hemodialysis. We examined 207 patients (mean age: 63.1 years; men: 66.2%) undergoing hemodialysis for more than 6 months in hospital affiliated clinic. PMTH was calculated at the L3 vertebra level using CT. Patients were divided according to the PMTH cut-off points: 8.44 mm/m in women and 8.85 mm/m in men; thereafter, they were combined into low and high PMTH groups. PMTH was independently correlated with the simplified creatinine index (β = 0.213, P = 0.021) and geriatric nutritional risk index (β = 0.295, P < 0.0001) in multivariate regression analysis. During a median follow-up of 3.7 (1.8–6.4) years, 76 patients died, including 41 from cardiovascular causes. In the multivariate Cox regression analysis, low PMTH (adjusted hazard ratio, 2.48; 95% confidence interval, 1.36–4.70) was independently associated with an increased risk of all-cause mortality. The addition of binary PMTH groups to the baseline risk model tended to improve net reclassification improvement (0.460, p = 0.060). In conclusion, PMTH may be an indicator of protein energy wasting and a useful tool for predicting mortality in patients undergoing hemodialysis.

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

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

Psoas muscle index predicts osteoporosis and fracture risk in individuals with degenerative spinal disease

OBJECTIVES

Skeletal muscle loss and osteoporosis are major medical and socioeconomic concerns as the global population ages. Studies have reported that skeletal muscle mass correlates to bone mineral density (BMD). The psoas muscle index (PMI), measured as the L3 cross-sectional areas of the right and left psoas divided by the square of height, has a positive correlation with the total volume of skeletal muscle in the body. This study aimed to evaluate relationships between PMI and BMD and fracture risk estimated by the Fracture Risk Assessment Tool (FRAX).

METHODS

Preoperatively acquired, plain computed tomography images at the L3 level were used to measure PMI in 87 people with degenerative spinal diseases. We evaluated the correlation between PMI and BMD and fracture risk estimated by FRAX.

RESULTS

PMI was significantly correlated with BMD in the entire lumbar spine and femoral neck (r = 0.413 and 0.525, both P < 0.001). People with osteoporosis showed significantly lower PMI than those without (P < 0.05). PMI was also significantly correlated with FRAX score (r = -0.545, P < 0.001). Furthermore, based on the recommendation of osteoporosis treatment, participants were divided into two groups: FRAX ≥15% (R group) and FRAX <15% (C group). The R group showed significantly lower PMI than the C group (P < 0.001). Receiver operating characteristic curve analysis revealed that PMI has moderate accuracy in diagnosing osteoporosis and FRAX ≥15%.

CONCLUSIONS

PMI was significantly associated with BMD and fracture risk. PMI measurement is straightforward and may increase the diagnosis rate of osteoporosis and fracture risk.

Association Between the Normal-Density Psoas Muscle Index and Handgrip Strength or Gait Speed in Maintenance Hemodialysis Patients

Introduction: This study aimed to evaluate the association between the psoas muscle (PM) index with or without fatty infiltration and various indices associated with muscle mass in hemodialysis (HD) patients.

Methods: We included stable HD patients (n = 83). The collected data included subjective global assessment (SGA) score, ASM/Ht² (appendicular skeletal muscle mass divided by the squared height in meters), gait speed (GS; m/s), and handgrip strength (HGS; kg). The abdominal computed tomography (CT) image was obtained using a CT scanner. The PM and normal-density PM (NPM) indices (mm²/m²) were calculated using the whole PM area or the area with an attenuation range of 35–100 HU divided by the squared height in meters.

Results: Correlation coefficients for the SGA score, ASM/Ht², HGS, and GS were greater for the NPM index than for the PM index. The linear regression analysis showed that, on multivariate analysis, the NPM index was significantly associated with the SGA score, ASM/Ht², and GS. However, the PM index was significantly associated with the SGA score and ASM/Ht² but not with HGS or GS. For calculating the low GS, the area under the receiver operating characteristic curve area was significantly greater for the NPM index than for the PM index (P = 0.012).

Conclusion: The present study suggested that the NPM index excluding fatty infiltration may be an early and useful indicator for detecting muscle strength and physical performance among HD patients.

Preoperative sarcopenia is associated with late mortality after off-pump coronary artery bypass grafting

OBJECTIVES

We investigated the association between sarcopenia (a marker of frailty) and outcomes after coronary artery bypass grafting (CABG).

METHODS

This study included 304 patients who underwent elective isolated off-pump CABG at our hospital between October 2008 and August 2013. Psoas muscle area was measured on preoperative computed tomography scans. Sarcopenia was defined as the lowest sex-specific quartile of the psoas muscle area index (the psoas muscle area normalized for height). Patients were categorized into a sarcopenia group (76 patients) and a non-sarcopenia group (228 patients). Patients in the sarcopenia group were older and showed a lower body mass index, lower serum haemoglobin and albumin levels and lower prevalence of dyslipidaemia but higher prevalence of renal dysfunction and peripheral artery disease. The mean follow-up period was 4.5 ± 2.3 years.

RESULTS

The cut-off values for sarcopenia were psoas muscle area index 215 and 142 mm2/m2 in men and women, respectively. No intergroup difference was observed in the in-hospital mortality and morbidity rates. After risk adjustment using inverse probability weighting analysis, late mortality rates were significantly higher in the sarcopenia group than in the non-sarcopenia group (P = 0.022). Multivariable analysis showed that preoperative sarcopenia was an independent predictor of late mortality (hazard ratio 4.25, 95% confidence interval 2.18-8.28; P < 0.001). Preoperative sarcopenia was not associated with major adverse cardiac and cerebrovascular events during follow-up.

CONCLUSIONS

Preoperative sarcopenia (assessed by psoas muscle area index) was associated with late mortality after CABG and effectively predicts postoperative prognosis.

Sarcopenia predicts perioperative adverse events following complex revision surgery for the thoracolumbar spine

BACKGROUND CONTEXT

Sarcopenia measured by psoas muscle index (PMI) has been shown to predict perioperative mortality and adverse events (AEs) after various surgical procedures. However, this relationship has not been studied in complex revision thoracolumbar spine surgery.

PURPOSE

This study aimed to determine the relationship between sarcopenia and perioperative AEs among patients undergoing complex revision thoracolumbar spine surgery.

STUDY DESIGN

Retrospective cohort study PATIENT SAMPLE: A retrospective analysis was performed at a single institution between May 2016 and February 2020 of patients undergoing complex revision thoracolumbar spine surgery by three board certified fellowship-trained orthopaedic spine surgeons.

OUTCOME MEASURES

Perioperative adverse events including postoperative anemia requiring transfusion, cardiac complication, sepsis, wound complication, delirium, intra-operative dural tear, acute kidney injury, pneumonia, urinary tract infection, urinary retention, epidural hematoma, and deep vein thrombosis. Secondary outcome measures were 30-day readmission rates, 30-day re-operation rates, in-hospital mortality rates, discharge disposition, and postoperative length of stay (LOS).

METHODS

Sarcopenia was analyzed using PMI, calculated at the L3 vertebral body measured on preoperative magnetic resonance imaging (MRI) or computed tomography (CT) normalized to height² (mm²/m²). Receiver operating characteristic (ROC) curve analysis and Youden index were used to determine gender-specific PMI cut-off values for predicting perioperative AEs. Sarcopenia was defined as PMI below the cut-off values. Complex revision surgery was defined as Spine Surgical Invasiveness Index >10.

RESULTS

A total of 114 consecutive patients were included in the study. ROC curve analysis demonstrated PMI <500 mm²/m² for males and <412 mm²/m² for females as predictors for perioperative AEs. 49 patients were in the sarcopenia cohort and 65 patients in the nonsarcopenia cohort. The sarcopenia group had higher overall perioperative AEs (75.5% vs 27.7%, p<.001) and individual AEs including: postoperative anemia requiring transfusion, wound complication, delirium, acute kidney injury, pneumonia, urinary tract infection, and deep vein thrombosis. The sarcopenia group had higher 30-day reoperation rate (14.3% vs 3.1%, p=.037), 30-day readmission rate (16.3% vs 3.1%, p=.018), rate of discharge to a facility (83.7% vs 50.8%, p<.001), and longer length of stay (LOS) (7.3±4.2 days vs 5.6±3.5 days, p=.023).

CONCLUSIONS

Sarcopenia measured by PMI is associated with higher perioperative AEs, 30-day readmission rates, 30-day reoperation rates, rate of discharge to a facility, and longer LOS among patients undergoing complex revision thoracolumbar spine surgery.

Muscle mass evaluation using psoas muscle mass index by computed tomography imaging in hemodialysis patients

BACKGROUND AND AIMS

The use of the psoas muscle mass index (PMI) using computed tomography (CT) has become a marker of interest to evaluate whole body muscle mass. However, in hemodialysis (HD) patients, reports about the clinical significance of psoas muscle evaluation are limited. We aimed to clarify the association between PMI and skeletal muscle mass index (SMI) using bioelectrical impedance analysis (BIA), and to investigate factors affecting PMI in HD patients.

METHODS

In this prospective observational study, to evaluate muscle mass, SMI was measured using BIA after HD, and PMI was measured by the manual trace method on routinely available CT scans. PMI measurement was assessed twice by two physicians to compute intra-rater and inter-rater reliability. The correlations between PMI and the clinical factors were evaluated using Pearson's correlation coefficient and a linear regression analysis. Variables with a p-value < 0.05 in the simple linear regression analysis were included in the multivariable linear regression analysis to identify the factors that affected PMI of the HD patients.

RESULTS

Fifty HD patients were recruited (31 males and 19 females; HD duration, 9.0 ± 8.8 years). The SMI was 6.10 ± 1.20 kg/m², and the PMI was 4.79 ± 1.61 cm²/m². Regarding the reliability of PMI measurements, intra-rater reliability [intra-class correlation (ICC) = 0.999] and inter-rater reliability (ICC = 0.998) were high in this study. The mean PMI of male patients was 5.40 ± 1.62 cm²/m², while that of female patients was significantly lower (3.78 ± 0.98 cm²/m²; p < 0.001). The PMI was significantly and positively correlated with SMI (r = 0.630, p < 0.001), in addition to HD duration, body mass index (BMI), serum phosphate and serum creatinine (Cr). In the multivariate linear regression analysis by two models using SMI or BMI, they were respectively extracted as an independent factor associating with PMI, in addition to serum Cr and the difference of sex.

CONCLUSIONS

PMI assessed with CT positively correlated with SMI measured using BIA. PMI might be one of the methods for evaluating the muscle mass in HD patients, when CT scans are taken as part of routine care.

Impact of Preoperative Low Prognostic Nutritional Index and High Intramuscular Adipose Tissue Content on Outcomes of Patients with Oral Squamous Cell Carcinoma

The impact of preoperative malnutrition and sarcopenia on survival in oral squamous cell carcinoma (OSCC) patients remains controversial. We investigated the effects of the preoperative nutritional status and abnormalities in body composition on the mortality of OSCC patients. A retrospective study involving 103 patients with OSCC was conducted. Disease-specific survival (DSS) according to the preoperative psoas muscle mass index (PMI) and intramuscular adipose tissue content (IMAC) was evaluated. Univariate and multivariate analyses were performed to determine the predictive performance of the covariates with respect to DSS. The DSS rate in patients with high IMAC and low PMI was significantly lower than that in controls. Multivariate analysis revealed that a low preoperative Prognostic Nutritional Index (PNI) and high IMAC were independent risk factors. We demonstrated that preoperative malnutrition and abnormal body composition, such as preoperative skeletal muscle quality, are associated with DSS in OSCC patients. Our study suggests that the evaluation of preoperative malnutrition and skeletal muscle quality would be useful for predicting mortality in patients with OSCC.

Cachexia, muscle wasting, and frailty in cardiovascular disease

The last several years have seen increasing interest in understanding cachexia, muscle wasting, and physical frailty across the broad spectrum of patients with cardiovascular illnesses. This interest originally started in the field of heart failure, but has recently been extended to other areas such as atrial fibrillation, coronary artery disease, peripheral artery disease as well as to patients after cardiac surgery or transcatheter aortic valve implantation. Tissue wasting and frailty are prevalent among many of the affected patients. The ageing process itself and concomitant cardiovascular illness decrease lean mass while fat mass is relatively preserved, making elderly patients particularly prone to develop wasting syndromes and frailty. The aim of this review is to provide an overview of the available knowledge of body wasting and physical frailty in patients with cardiovascular illness, particularly focussing on patients with heart failure in whom most of the available data have been gathered. In addition, mechanisms of wasting and possible therapeutic targets are discussed.

Skeletal muscle quality affects patient outcomes in acute type A aortic dissection

OBJECTIVES

Although skeletal muscle quantity is linked to surgical outcomes, quality remains unexamined. In this study, we evaluated whether skeletal muscle quality and quantity could predict surgical outcomes in acute type A aortic dissection (ATAAD).

METHODS

Skeletal muscle quality and quantity were evaluated using computed tomography (CT) values and the psoas muscle mass index, respectively. From May 2004 to December 2017, 324 ATAAD patients underwent aortic replacement after CT scans and psoas muscle mass index measurements. Patients were grouped into intramuscular fat (IMF; n = 55) and non-IMF (n = 269) deposition groups.

RESULTS

The mean ages of the patients were 72.3 ± 9.7 and 66.8 ± 12.1 years (P = 0.002), and hospital mortality rates were 3.6% (2/55) and 7.4% (20/269; P = 0.393) for IMF and non-IMF deposition groups, respectively. IMF deposition was a risk factor for a deterioration in activities of daily living at discharge by multivariable analysis [odds ratio 0.33, 95% confidence interval (CI) 0.16-0.69; P = 0.003]. The mean follow-up was 43.9 ± 36.8 months. The 5-year survival was significantly worse for the IMF deposition group (IMF 73.8% vs non-IMF 88.2%; P = 0.010). The multivariable Cox proportional hazard analysis showed that IMF deposition significantly predicted poor survival (hazard ratio 3.26, 95% CI 1.47-7.24; P = 0.004), unlike psoas muscle mass index and age.

CONCLUSIONS

Skeletal muscle quality, defined by IMF deposition, was an independent predictor of overall survival and postoperative activities of daily living dependence risk in patients undergoing surgery for ATAAD. Thus, IMF deposition may be an additional risk factor for estimating late outcomes of ATAAD surgery.