Skeletal Muscle Quantity Research Articles

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

Computerized tomography (CT) is considered the gold standard for the evaluation of total skeletal muscle quantity. Skeletal muscle assessments at the L3 vertebra level revealed significantly correlated with total body muscle measurements. Clinicians need cut-offs to evaluate low muscle mass in various patients who already had CT imaging without any additional cost. This assessment is important to help the physicians to stratify the patients for mortality and other complications. It may also enable the diagnosis of malnutrition by the GLIM criteria. Few studies reported cut-offs in different populations. We aimed to provide cut-off values for total skeletal muscle index (SMI) and psoas muscle mass index (PMI) at the L3 vertebra level in the Turkish population. We assessed the preoperative plain CT images of living adult liver donors who were admitted to a single transplantation center between June 2010 and April 2018. We derived cut-off values with two alternative methods, the 5th percentile value or mean minus two standard deviations and from two groups of study participants, i.e. the total study population and the younger subgroup aged between 18 and 40. The study population involved 601 subjects with a mean age of 32.5±9 (range: 18-59 years) and 326 (54.2%) was male. The younger subgroup was composed of 482 individuals with a mean age of 28.8±5.9 and 55.6% male. In patients aged between 18 and 40, PMI and SMI cut-offs by using the 5th percentile were 5.40cm2/m2, 41.42cm2/m2 for males; and 3.56cm2/m2, 30.70cm2/m2 for females; respectively. The cut-offs of PMI and SMI by using mean minus two standard deviations were 4.62cm2/m2, 38.67cm2/m2 for males; and 2.66cm2/m2, 27.8cm2/m2 for females; respectively. These cut-offs were comparable to the other populations. Our study provided cut-offs to be used in CT images for PMI and SMI. There is a need for further longitudinal studies to verify whether these cut-offs are successful in predicting mortality or other adverse outcomes associated with low muscle mass.

The Role of Home-Based Exercise in Maintaining Skeletal Muscle During Preoperative Pancreatic Cancer Treatment.

Loss of skeletal muscle and inferior muscle quality are associated with poor prognosis in patients undergoing preoperative treatment for pancreatic cancer, so maintaining skeletal muscle health before surgery may help accelerate patients’ functional recovery and improve their quality of life following surgery. While exercise helps maintain or increase skeletal muscle in individuals undergoing cancer treatment, its efficacy during pancreatic cancer treatment is unclear. Accordingly, in this study we compared changes in skeletal muscle quantity (skeletal muscle index [SMI]) and quality (skeletal muscle density [SMD]) during preoperative pancreatic cancer treatment in participants in a home-based exercise program (EP) and a historical cohort of patients who received the usual care (UC) with no formal exercise programming. Recommendations for the EP cohort included both aerobic and resistance exercise. We assessed changes in SMI and SMD using computed tomography scans administered at treatment planning (T0, prior to EP enrollment) and preoperative restaging (T1) for 33 EP and 64 UC patients and compared changes between groups. The UC patients had statistically significant SMI decreases from T0 to T1 (−1.4 ± 3.8 cm2/m2; p = .005), while the EP patients did not (0.2 ± 3.2 cm2/m2; p = .7). The SMI loss was significantly worse for the UC than for the EP patients (p = .03). Neither group demonstrated statistically significant changes in SMD from T0 to T1, nor did the groups differ in the amount of change in SMD. An adjusted linear regression model demonstrated that EP participation was significantly associated with better SMI maintenance (p = .02). These results suggest that participation in a home-based EP during preoperative treatment may help improve skeletal muscle health and clinical and quality of life outcomes for pancreatic cancer survivors.

Validity of Extended-Field-of-View Ultrasound Imaging to Evaluate Quantity and Quality of Trunk Skeletal Muscles

This study examined the validity of extended-field-of-view (EFOV) ultrasound imaging for evaluating the quantity (cross-sectional area [CSA]) and quality (accumulation of intramuscular fat) of trunk skeletal muscles (rectus abdominis, abdominal oblique and erector spinae) using magnetic resonance imaging (MRI) as a reference. Thirty healthy young men participated in this study. Cross-sectional images of the trunk at the height of the third lumbar vertebra were acquired and compared by EFOV ultrasound imaging and MRI. No significant differences were observed in CSAs between the two methods (0.74 ≤ R2 ≤ 0.85). Echo intensities significantly correlated with MRI-derived accumulation of intramuscular fat in each skeletal muscle group. However, the correlation coefficients were relatively low (0.37 ≤ r ≤0.47; p < 0.05). These results indicate that EFOV ultrasound imaging is a reliable method for assessing trunk skeletal muscle CSA. Further research is warranted to find the optimal ultrasound setting for evaluating muscle quality.

Chronic inflammation and muscle depletion in cirrhosis patients

Rationale: Sarcopenia is recognized as a common complication in patients with cirrhosis awaiting LT. The pathogenesis of sarcopenia in cirrhosis is multifactorial and results fundamentally from an imbalance between protein synthesis and breakdown. Cirrhosis is a proinflammatory condition in which exists elevated levels of C-reactive protein (CPR) and systemic inflammatory cytokines. Computed tomography (CT) scans, when taken as part of routine care pre liver transplant, provide an excellent opportunity to precisely measure the quantity and quality of skeletal muscle and adipose tissue.

Breath isoprene excretion during rest and low-intensity cycling exercise is associated with skeletal muscle mass in healthy human subjects

The physiological roles of isoprene, which is one of the many endogenous volatile organic compounds contained in exhaled breath, are not well understood. In recent years, exhaled isoprene has been associated with the skeletal muscle. Some studies have suggested that the skeletal muscle produces and/or stores some of the isoprene. However, the evidence supporting this association remains sparse and inconclusive. Furthermore, aging may affect breath isoprene response because of changes in the skeletal muscle quantity and quality. Therefore, we investigated the association between the breath isoprene excretion () and skeletal muscle mass in young (n = 7) and old (n = 7) adults. The participants performed an 18 min cycling exercise after a 3 min rest. The workload corresponded to an intensity of 30% of the heart rate reserve, as calculated by the Karvonen formula. The exhaled breath of each participant was collected during the exercise test. We calculated from the product minute ventilation and isoprene concentration and, then, investigated the relationships between and muscle mass, which was measured by multi-frequency bioelectrical impedance analysis. Importantly, muscle mass persisted as a significant determinant that explained the variance in at rest even after adjusting for age. Furthermore, the muscle mass was a significant determinative factor for response during exercise, regardless of age. These data indicated that skeletal muscle mass could be one of the determinative factors for during rest and response to exercise. Thus, we suggest that the skeletal muscle may play an important role in generating and/or storing some of the endogenous isoprene. This new knowledge will help to better understand the physiological functions of isoprene in humans (Approval No. 20190079).

Impacts of Green Tea on Joint and Skeletal Muscle Health: Prospects of Translational Nutrition.

Osteoarthritis and sarcopenia are two major joint and skeletal muscle diseases prevalent during aging. Osteoarthritis is a multifactorial progressive degenerative and inflammatory disorder of articular cartilage. Cartilage protection and pain management are the two most important strategies in the management of osteoarthritis. Sarcopenia, a condition of loss of muscle mass and strength, is associated with impaired neuromuscular innervation, the transition of skeletal muscle fiber type, and reduced muscle regenerative capacity. Management of sarcopenia requires addressing both skeletal muscle quantity and quality. Emerging evidence suggests that green tea catechins play an important role in maintaining healthy joints and skeletal muscle. This review covers (i) the prevalence and etiology of osteoarthritis and sarcopenia, such as excessive inflammation and oxidative stress, mitochondrial dysfunction, and reduced autophagy; (ii) the effects of green tea catechins on joint health by downregulating inflammatory signaling mediators, upregulating anabolic mediators, and modulating miRNAs expression, resulting in reduced chondrocyte death, collagen degradation, and cartilage protection; (iii) the effects of green tea catechins on skeletal muscle health via maintaining a dynamic balance between protein synthesis and degradation and boosting the synthesis of mitochondrial energy metabolism, resulting in favorable muscle homeostasis and mitigation of muscle atrophy with aging; and (iv) the current study limitations and future research directions.

Effect of Intradialytic Oral Nutritional Supplementation with and Without Exercise on the Skeletal Muscle Quantity and Quality of Adult Hemodialysis Patients

Effect of Intradialytic Oral Nutritional Supplementation with and Without Exercise on the Skeletal Muscle Quantity and Quality of Adult Hemodialysis Patients

The Effect of MicroRNA-Mediated Exercise on Delaying Sarcopenia in Elderly Individuals.

Sarcopenia is often regarded as an early sign of weakness and is the core element of muscle weakness in elderly individuals. Sarcopenia is closely related to the reduction of exercise, and elderly individuals often suffer from decreased muscle mass and function due to a lack of exercise. At present, studies have confirmed that resistance and aerobic exercise are related to muscle mass, strength and fiber type and to the activation and proliferation of muscle stem cells (MuSCs). Increasing evidence shows that microRNAs (miRNAs) play an important role in exercise-related changes in the quantity, composition and function of skeletal muscle. At the cellular level, miRNAs have been shown to regulate the proliferation and differentiation of muscle cells. In addition, miRNAs are related to the composition and transformation of muscle fibers and involved in the transition of MuSCs from the resting state to the activated state. Therefore, exercise may delay sarcopenia in elderly individuals by regulating miRNAs in skeletal muscle. In future miRNA-focused treatment strategies, these studies will provide valuable information for the formulation of exercise methods and will provide useful and targeted exercise programs for elderly individuals with sarcopenia.

Body composition analysis using CT and MRI: intra-individual intermodal comparison of muscle mass and myosteatosis

Computed tomography (CT) and magnetic resonance imaging (MRI) can quantify muscle mass and quality. However, it is still unclear if CT and MRI derived measurements can be used interchangeable. In this prospective study, fifty consecutive participants of a cancer screening program underwent same day low-dose chest CT and MRI. Cross-sectional areas (CSA) of the paraspinal skeletal muscles were obtained. CT and MRI muscle fat infiltration (MFI) were assessed by mean radiodensity in Hounsfield units (HU) and proton density fat fraction (MRIPDFF), respectively. CSA and MFI were highly correlated between CT and MRI (CSA: r = 0.93, P < 0.001; MFI: r = − 0.90, P < 0.001). Mean CSA was higher in CT compared to MRI (46.6cm2 versus 43.0cm2; P = 0.05) without significance. Based on MRIPDFF, a linear regression model was established to directly estimate skeletal muscle fat content from CT. Bland–Altman plots showed a difference between measurements of − 0.5 cm2 to 7.6 cm2 and − 4.2% to 2.4% regarding measurements of CSA and MFI, respectively. In conclusion, the provided results indicate interchangeability of CT and MRI derived imaging biomarkers of skeletal muscle quantity and quality. Comparable to MRIPDFF, skeletal muscle fat content can be quantified from CT, which might have an impact of analyses in larger cohort studies, particularly in sarcopenia patients.

Impact of intramuscular adipose tissue content on short- and long-term outcomes of hepatectomy for colorectal liver metastasis: a retrospective analysis

BackgroundNumerous reports regarding sarcopenia have focused on the quantity of skeletal muscle. In contrast, the impact of the quality of skeletal muscle has not been well investigated.MethodsA retrospective analysis of 115 patients who underwent initial hepatectomy for colorectal liver metastasis between January 2009 and December 2016 in our hospital was performed. Intramuscular adipose tissue content (IMAC) was used to evaluate the quality of skeletal muscle by analysing computed tomography (CT) images at the level of the umbilicus. The impact of poor skeletal muscle quality on short-term and long-term outcomes after hepatectomy for colorectal liver metastasis was analysed.ResultsPatients were divided into two groups (high IMAC and normal IMAC) according to their IMAC values, and their backgrounds were compared. There were no significant differences in most factors between the two groups. However, both body mass index (P = 0.030) and the incidence of postoperative complications of Clavien-Dindo grade 3 or worse (P = 0.008) were significantly higher in the high-IMAC group. In multivariate analyses, an operative blood loss > 600 ml (P = 0.006) and high IMAC (P = 0.008) were associated with postoperative complications of Clavien-Dindo grade 3 or worse. Overall survival and recurrence-free survival were significantly lower (P < 0.001 and P = 0.045, respectively) in the high-IMAC group than in the normal IMAC group. In multivariate analyses for poor overall survival, high IMAC was associated with poor overall survival (P < 0.001).ConclusionsIMAC is a prognostic factor for poor short- and long-term outcomes in patients with colorectal liver metastasis.

Trunk muscle quality and quantity predict the development of metabolic syndrome and the increase in the number of its components in individuals without metabolic syndrome

Background and aimsThe metabolic syndrome has been reported by cross-sectional studies to have an association with skeletal muscle quality and quantity. Using a longitudinal study design, this study aimed to explicate the association between muscle characteristics assessed with computed tomography (CT) and the incidence and progression of metabolic syndrome. Methods and resultsIn this retrospective study on a cohort of employees undergoing annual physical examinations, we evaluated data from 554 participants without metabolic syndrome. The cross-sectional skeletal muscle area was determined based on CT data at the level of the third lumbar vertebra, and the skeletal muscle density (SMD) and skeletal muscle index (SMI) were measured. The participants were divided into four study groups according to the sex-specific median values for SMI and SMD. We followed the participants for a mean period of 3.1 years. In the sex- and age-adjusted model, SMI and SMD had an interaction effect on the longitudinal change in number of metabolic syndrome components (β = −0.074, p = 0.0727). Multiple regression analyses revealed that both low SMI and SMD was significantly associated with the change (β = 0.131, p = 0.0281), whereas the low SMI and high SMD, and high SMI and low SMD were not. Both low SMI and SMD (hazard ratio (HR), 2.42; 95% confidence interval, 1.28–4.78) showed an increased adjusted HR for incident metabolic syndrome. ConclusionThe participants with both low quality and quantity of skeletal muscles were associated with the incidence and progression of metabolic syndrome, whereas those with only low quantity or quality of skeletal muscles were not.

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

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). 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. 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. 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.

Abstract 12: Skeletal Muscle Density, Not Size, is Beneficially Associated With Incident Coronary Heart Events: The Multi-Ethnic Study of Atherosclerosis

Introduction: Fat infiltration into muscle reduces muscle density and increases the risk for metabolic dysfunction, mobility disability and mortality. We assessed abdominal muscle density and muscle area in relation to incident coronary heart disease (CHD) events. Methods: Adults (mean age 64.6 ± 9.6) from the Multi-Ethnic Study of Atherosclerosis body composition ancillary study had computed tomography (CT)-derived measures of muscle density, muscle area and visceral fat at the L2-L4 spinal column levels between 2002-05 and were followed for incident events. Using sex-stratified Cox proportional hazards regression, associations of muscle density and muscle area (in the same model) with CHD events were assessed using restricted cubic splines with adjustment for confounders including visceral adiposity and BMI. Results: After 10.3±2.9 years of follow up, 924 males had 70 CHD (7.6%) events and 945 females had 44 CHD (4.7%) events. Muscle density was higher in males (44.5±4.9 HU) than females (40.1±5.2 HU), as was muscle area (116.7±23.9 vs. 80.4±23.9 cm 2 , respectively). Among males, and in mutually adjusted models, each incremental SD of muscle density was inversely associated with CHD (HR=0.67; 95%CI=0.49-0.92), while each SD of muscle area was associated with higher risk of CHD (HR=1.75; 95%CI=1.34-2.28; Figure). Overall patterns were similar but less strong among females for density (HR=0.79; 95%CI=0.50-1.22) and area (HR=1.17; 95%CI=0.79-1.73). Conclusions: Greater muscle density is associated with lower CHD risk, while greater muscle size is associated with increased CHD risk. These associations were independent of traditional CHD risk factors and measures of visceral and total body adiposity. Quantity and quality of skeletal muscle may represent distinct aspects of aging and physical functioning that are important in heart health.

Sarcopenia assessed by the quantity and quality of skeletal muscle is a prognostic factor for patients undergoing cardiac surgery.

Sarcopenia was assessed as a prognostic factor for patients undergoing cardiac surgery by evaluating the quantity and quality of skeletal muscle. Sarcopenia was assessed by perioperative abdominal computed tomography using the total psoas muscle index (TPI) and intra-muscular adipose tissue content (IMAC). Patients were classified into high- (HT, n = 143) and low- (LT, n = 63) TPI groups and low- (LI, n = 122) and high- (HI, n = 84) IMAC groups. There were significantly more complications in the LT and HI groups than in the HT and LI groups. (HT 15.4% vs. LT 30.2%, P = 0.014) (LI 11.5% vs. HI 31.1%, P < 0.001). There were more respiratory complications in the LT group (HT 0% vs. LT 6.3%, P = 0.002) and more surgical site infections in the HI group than in the LI group (LI 0.8% vs. HI 7.1%, P = 0.014). A multivariable analysis showed that low TPI and high IMAC significantly predicted more major complications than other combinations (odds ratio [OR] 2.375; 95% confidence interval [CI] 1.152-5.783; P = 0.036, OR 3.973; 95% CI 1.737-9.088; P = 0.001). Sarcopenia is a risk factor for complications. The quantity and quality of muscle must be assessed to predict operative outcomes. UMIN000027077.

Recent advances in understanding resistance exercise training-induced skeletal muscle hypertrophy in humans.

Skeletal muscle plays a pivotal role in the maintenance of physical and metabolic health and, critically, mobility. Accordingly, strategies focused on increasing the quality and quantity of skeletal muscle are relevant, and resistance exercise is foundational to the process of functional hypertrophy. Much of our current understanding of skeletal muscle hypertrophy can be attributed to the development and utilization of stable isotopically labeled tracers. We know that resistance exercise and sufficient protein intake act synergistically and provide the most effective stimuli to enhance skeletal muscle mass; however, the molecular intricacies that underpin the tremendous response variability to resistance exercise-induced hypertrophy are complex. The purpose of this review is to discuss recent studies with the aim of shedding light on key regulatory mechanisms that dictate hypertrophic gains in skeletal muscle mass. We also aim to provide a brief up-to-date summary of the recent advances in our understanding of skeletal muscle hypertrophy in response to resistance training in humans.

Low-attenuation muscle is a predictor of diabetes mellitus: A population-based cohort study.

Diabetes mellitus is a major global public health issue. Cross-sectional studies have demonstrated that skeletal muscle quality and quantity by computed tomography (CT) is related to glucose metabolism. However, to our knowledge, no longitudinal study has yet to elucidate the association between muscle quality determined by CT and glucose metabolism. Thus, the aim of this study was to evaluate the association between muscle quality and glucose metabolism. In this retrospective study, we evaluated data from 621 middle-aged Japanese individuals without diabetes mellitus from a cohort of employees undergoing annual physical examinations. The cross-sectional skeletal muscle area was determined based on CT data at the level of the third lumbar vertebrae, and the skeletal muscle index (SMI) and density (SMD) were calculated. Low-attenuation muscle (LAM) and normal-attenuation muscle (NAM) were identified and quantified using thresholds of -29 to +29 HU and +30 to +150 HU, respectively. We followed the individuals for a mean period of 3 y, and 27 of them developed diabetes mellitus during this period. Multiple Cox regression analyses revealed that, even after adjustment for visceral fat area index, the LAM index (hazard ratio [HR], 3.07; 95% confidence interval [CI], 1.00-7.52) showed an increased adjusted HR for incident diabetes mellitus. When total SMI and SMD were used in the same models, only total SMD (HR, 0.90; 95% CI, 0.81-0.99) showed a decreased adjusted HR for incident diabetes mellitus. Both LAM index and total SMD were associated with a higher risk for incident diabetes mellitus, whereas NAM index and total SMI were not.

Automated body composition analysis of clinically acquired computed tomography scans using neural networks.

The quantity and quality of skeletal muscle and adipose tissue is an important prognostic factor for clinical outcomes across several illnesses. Clinically acquired computed tomography (CT) scans are commonly used for quantification of body composition, but manual analysis is laborious and costly. The primary aim of this study was to develop an automated body composition analysis framework using CT scans. CT scans of the 3rd lumbar vertebrae from critically ill, liver cirrhosis, pancreatic cancer, and clear cell renal cell carcinoma patients, as well as renal and liver donors, were manually analyzed for body composition. Ninety percent of scans were used for developing and validating a neural network for the automated segmentation of skeletal muscle and adipose tissues. Network accuracy was evaluated with the remaining 10 percent of scans using the Dice similarity coefficient (DSC), which quantifies the overlap (0=no overlap, 1=perfect overlap) between human and automated segmentations. Of the 893 patients, 44% were female, with a mean (±SD) age and body mass index of 52.7 (±15.8) years old and 28.0 (±6.1) kg/m2, respectively. In the testing cohort (n=89), DSC scores indicated excellent agreement between human and network-predicted segmentations for skeletal muscle (0.983±0.013), and intermuscular (0.900±0.034), visceral (0.979±0.019), and subcutaneous (0.986±0.016) adipose tissue. Network segmentation took ~350 milliseconds/scan using modern computing hardware. Our network displayed excellent ability to analyze diverse body composition phenotypes and clinical cohorts, which will create feasible opportunities to advance our capacity to predict health outcomes in clinical populations.

The intersection of exercise and aging on mitochondrial protein quality control.

Skeletal muscle quality and quantity are negatively impacted with age. Part of this decline in function can be attributed to alterations in mitochondrial turnover, and in the mechanisms that regulate mitochondrial homeostasis. Protein quality control within the mitochondria relies on a number of interconnected processes, namely the mitochondrial unfolded protein response (UPRmt), protein import and mitophagy. In particular, the post-transcriptional regulation of protein import into the organelle has generated considerable recent interest in view of its dynamic versatility. The capacity for import can be increased by chronic exercise, and diminished by muscle disuse, and defects in the import pathway can be rescued by exercise. Within mitochondria, the unfolded protein response (UPR) is activated if protein import is altered, or if protein misfolding takes place. This UPR generates retrograde signaling to the nucleus to activate compensatory gene expression and protein synthesis. Mitophagy is also elevated with age, contributing to the lower mitochondrial content in aging muscle. However, mitophagy is amenable to exercise adaptations, as it is activated with each exercise bout, presumably to mediate mitochondrial quality control. However, this response is attenuated in older subjects. Although not yet completely elucidated, numerous molecular processes involved in mitochondrial biogenesis and turnover are affected with age. The contrasting and often opposite consequences of exercise and age suggest that exercise can serve as non-pharmacological "mitochondrial medicine" for aging muscle to ameliorate mitochondrial content and function, via pathways that implicate organelle protein quality control mechanisms.

P13 Role of Adipose Tissue and Skeletal Muscle in Peripheral Arterial Disease

BackgroundPeripheral arterial disease (PAD) is a manifestation of atherosclerosis. Adipose tissue (AT) and skeletal muscle (SM) are endocrine organs with vascular effects. The objective is to compare the quantity and function of AT and SM between two groups: intermittent claudication (IC) and critical limb ischemia (CLI).MethodsA prospective observational study is being performed. A transverse CT image at lower border the third lumbar vertebra was used to quantify the SM, visceral and subcutaneous AT. The SM function was inferred with the determination of hand strength using a Jamar® hydraulic hand dynamometer.ResultsFrom December 2018 to May 2019, 44 PAD were studied: 31 with IC (24 male; age: 67 10, 29 years) and 13 CLI (7 male; age: 70, 62 6, 74 years). CLI have a lower quantity of subcutaneous AT and higher quantity of visceral and total AT, determined on the CT scan (subcutaneous AT: 16564,75 7600,00 cm2 IC versus 16067,42 10187,33 cm2 CLI p = 0.03; visceral AT: 17212,20 10096, 30 cm2 IC versus 18904,85 10189,04 cm2 CLI p = 0,03; Total AT: 33222,08 15459,33 cm2 IC versus 57320,00 52538,78 cm2 CLI p = 0.03). CLI had lower SM strength and density (muscle strength right hand: 22,62 8,20 Kgf IC versus 16,38 7,84 Kgf CLI p = 0,02; SM strength left hand: 21,98 8,98 Kgf IC versus 16,37 8,35 Kgf CLI p = 0,04; SM density: 20,44 11,73 HU IC versus 9,04 28,47 HU CLI p = 0,01) No differences were found in the SM quantity (15120,87 3199,35 cm2 IC versus 15322,57 5315,31 cm2 CLI p = 0.44).ConclusionCLI have a higher quantity of visceral, total AT and lower quantity of subcutaneous AT, SM function and density.

Impact of Preoperative Skeletal Muscle Mass and Quality on the Survival of Elderly Patients After Curative Resection of Colorectal Cancer.

Objective: Skeletal muscle loss (sarcopenia) is a prognostic factor in patients undergoing gastrointestinal surgery. However, the influence of muscle quality on prognosis remains unclear. We retrospectively examined preoperative skeletal muscle quantity and quality impact on survival of elderly patients undergoing curative resection of colorectal cancer. Methods: We examined data from 142 patients aged ≥75 years who underwent curative resection of colorectal cancer between 2007 and 2012. We determined the size and quality of skeletal muscles, represented by the psoas muscle mass index (PMI) and intramuscular adipose tissue content (IMAC), respectively, using a preoperative computed tomography image. Overall survival (OS) and relapse-free survival (RFS) rates were determined according to values of PMI, IMAC, and other prognostic factors. Results: OS and RFS rates in patients with low PMI were lower than those in patients with normal PMI. The OS and RFS rates in patients with high IMAC were also lower than those in patients with normal IMAC. PMI and IMAC were independent prognostic factors for OS (hazard ratio [HR], 3.81, and 3.04, respectively); IMAC was an independent factor for RFS (hazard ratio [HR], 3.03). Conclusion: Preoperative sarcopenia, indicating low quality and size of skeletal muscle, predicts mortality after curative resection of colorectal cancer in the elderly.