Transcriptome profiling of fast/glycolytic and slow/oxidative muscle fibers in aging and obesity.

Aging and obesity pose significant threats to public health and are major contributors to muscle atrophy. The trends in muscle fiber types under these conditions and the transcriptional differences between different muscle fiber types remain unclear. Here, we demonstrate distinct responses of fast/glycolytic fibers and slow/oxidative fibers to aging and obesity. We found that in muscles dominated by oxidative fibers, the proportion of oxidative fibers remains unchanged during aging and obesity. However, in muscles dominated by glycolytic fibers, despite the low content of oxidative fibers, a significant decrease in proportion of oxidative fibers was observed. Consistently, our study uncovered that during aging and obesity, fast/glycolytic fibers specifically increased the expression of genes associated with muscle atrophy and inflammation, including Dkk3, Ccl8, Cxcl10, Cxcl13, Fbxo32, Depp1, and Chac1, while slow/oxidative fibers exhibit elevated expression of antioxidant protein Nqo-1 and downregulation of Tfrc. Additionally, we noted substantial differences in the expression of calcium-related signaling pathways between fast/glycolytic fibers and slow/oxidative fibers in response to aging and obesity. Treatment with a calcium channel inhibitor thapsigargin significantly increased the abundance of oxidative fibers. Our study provides additional evidence to support the transcriptomic differences in muscle fiber types under pathophysiological conditions, thereby establishing a theoretical basis for modulating muscle fiber types in disease treatment.

Characteristics and prognostic impact of cancer cachexia defined by the Asian Working Group for Cachexia consensus in patients with curable gastric cancer.

BACKGROUND: Cachexia is prevalent in cancer patients. The conventional diagnostic criteria for cachexia are often based on Western evidence, lacking consensus for Asian populations. This study aims to compare Asian Working Group for Cachexia (AWGC) criteria with Fearon's criteria, assessing their differences in population characteristics and prognostic impact. METHODS: The clinical data of patients who underwent radical gastrectomy between 2013 and 2019 were prospectively collected. Cachexia diagnosis involves the utilization of either AWGC criteria and the previous international consensus proposed by Fearon et al. A scoring model is established based on the optional criteria according to the AWGC criteria. Univariate and multivariate logistic and Cox regression analysis were conducted to determine the independent effect factors for postoperative complications and overall survival. RESULTS: In a total of 1330 patients, 461 met AWGC cachexia criteria and 311 met Fearon's criteria. Excluding 262 overlapping cases, those diagnosed solely with AWGC-cachexia had higher age and lower BMI, albumin, hemoglobin, and handgrip strength compared to those by Fearon's criteria alone. AWGC-cachexia independently increased the risk of postoperative complications, whereas Fearon's criteria did not. Patients with AWGC-cachexia also exhibited shorter overall survival than Fearon's criteria. The AWGC-based cachexia grading system effectively stratifies the risks of postoperative complications and mortality. CONCLUSIONS: The AWGC criteria is more effective in diagnosing cancer cachexia in the Asian population and provide better prognostic indicators.

Muscle attenuation, not skeletal muscle index, is an independent prognostic factor for survival in gastric cancer patients with overweight and obesity.

OBJECTIVES: Skeletal muscle index (SMI) is insufficient for evaluating muscle in obesity, and muscle attenuation (MA) may be a preferred indicator. This study aimed to investigate whether MA has greater prognostic value than SMI in gastric cancer patients with overweight and obesity. METHODS: Clinical parameters of 1312 patients with gastric cancer who underwent radical gastrectomy were prospectively collected between 2013 and 2019. MA and SMI were analyzed by computed tomography scan. Overweight/obesity was defined as body mass index (BMI) ≥24 kg/m2. The hazard ratio (HR) for death was calculated using Cox regression analysis. RESULTS: Among all patients, 405 were identified as overweight and obese, and 907 were identified as normal and underweight. MA was inversely associated with BMI and visceral fat area. Among the 405 patients with overweight and obesity, 212 patients (52%) were diagnosed with low MA. In the overweight/obese group, MA was an independent predictor for overall survival (HR, 1.610; P = 0.021) in multivariate Cox regression analyses, whereas SMI did not remain in the model. In the normal/underweight group, both low MA (HR, 1.283; P = 0.039) and low SMI (HR, 1.369; P = 0.008) were independent factors of overall survival. Additionally, 318 patients were identified as having visceral obesity in the overweight/obese group, and low MA was also an independent prognostic factor for survival in these patients (HR, 1.765; P = 0.013). CONCLUSION: MA had a higher prognostic value than SMI in overweight and obese patients with gastric cancer after radical gastrectomy.

Discovery of distinct cancer cachexia phenotypes using an unsupervised machine-learning algorithm.

OBJECTIVES: Cancer cachexia is a debilitating condition with widespread negative effects. The heterogeneity of clinical features within patients with cancer cachexia is unclear. The identification and prognostic analysis of diverse phenotypes of cancer cachexia may help develop individualized interventions to improve outcomes for vulnerable populations. The aim of this study was to show that the machine learning-based cancer cachexia classification model generalized well on the external validation cohort. METHODS: This was a nationwide multicenter observational study conducted from October 2012 to April 2021 in China. Unsupervised consensus clustering analysis was applied based on demographic, anthropometric, nutritional, oncological, and quality-of-life data. Key characteristics of each cluster were identified using the standardized mean difference. We used logistic and Cox regression analysis to evaluate 1-, 3-, 5-y, and overall mortality. RESULTS: A consensus clustering algorithm was performed for 4329 patients with cancer cachexia in the discovery cohort, and four clusters with distinct phenotypes were uncovered. From clusters 1 to 4, the clinical characteristics of patients showed a transition from almost unimpaired to mildly, moderately, and severely impaired. Consistently, an increase in mortality from clusters 1 to 4 was observed. The overall mortality rate was 32%, 40%, 54%, and 68%, and the median overall survival time was 21.9, 18, 16.7, and 13.6 mo for patients in clusters 1 to 4, respectively. Our machine learning-based model performed better in predicting mortality than the traditional model. External validation confirmed the above results. CONCLUSIONS: Machine learning is valuable for phenotype classifications of patients with cancer cachexia. Detection of clinically distinct clusters among cachexic patients assists in scheduling personalized treatment strategies and in patient selection for clinical trials.

Gli1 marks a sentinel muscle stem cell population for muscle regeneration.

Adult skeletal muscle regeneration is mainly driven by muscle stem cells (MuSCs), which are highly heterogeneous. Although recent studies have started to characterize the heterogeneity of MuSCs, whether a subset of cells with distinct exists within MuSCs remains unanswered. Here, we find that a population of MuSCs, marked by Gli1 expression, is required for muscle regeneration. The Gli1+ MuSC population displays advantages in proliferation and differentiation both in vitro and in vivo. Depletion of this population leads to delayed muscle regeneration, while transplanted Gli1+ MuSCs support muscle regeneration more effectively than Gli1- MuSCs. Further analysis reveals that even in the uninjured muscle, Gli1+ MuSCs have elevated mTOR signaling activity, increased cell size and mitochondrial numbers compared to Gli1- MuSCs, indicating Gli1+ MuSCs are displaying the features of primed MuSCs. Moreover, Gli1+ MuSCs greatly contribute to the formation of GAlert cells after muscle injury. Collectively, our findings demonstrate that Gli1+ MuSCs represents a distinct MuSC population which is more active in the homeostatic muscle and enters the cell cycle shortly after injury. This population functions as the tissue-resident sentinel that rapidly responds to injury and initiates muscle regeneration.

Sarcopenia and malignancies: epidemiology, clinical classification and implications.

Sarcopenia is a progressive systemic skeletal muscle disorder characterized by a pathological decline in muscle strength, quantity, and quality, which frequently affects the elderly population. The majority of cancer patients are of advanced age. Patients may already have sarcopenia prior to cancer development, and those with cancer are prone to developing sarcopenia due to hypercatabolism, inflammation, reduced physical fitness, anorexia, adverse effects, and stress associated with anticancer therapy. Based on the timing, sarcopenia in patients with cancer can be categorized into three: pre-existing sarcopenia before the onset of cancer, sarcopenia related to cancer, and sarcopenia related to cancer treatment. Sarcopenia not only changes the body composition of patients with cancer but also increases the incidence of postoperative complications, reduces therapeutic efficacy, impairs quality of life, and results in shortened survival. Different therapeutic strategies are required to match the cancer status and physical condition of patients with different etiologies and stages of sarcopenia. Here, we present a comprehensive review of the epidemiology and diagnosis of sarcopenia in patients with cancer, elucidate the complex interactions between cancer and sarcopenia, and provide evidence-based strategies for sarcopenia management in these patients.

Sarcopenia prevalence in patients with cancer and association with adverse prognosis: A nationwide survey on common cancers.

OBJECTIVE: Although previous studies have implicated the negative outcomes of sarcopenia, evidence is limited to one or a few types of cancer. The aim of this study was to evaluate the distribution and influencing factors of sarcopenia, and explore the relationship between sarcopenia and cancer prognosis in a large oncological population. METHODS: This observational cohort study included patients diagnosed with malignant cancer between May 2011 and January 2019. Hematologic and anthropometric parameters were collected prospectively. Low skeletal muscle mass and radiodensity were diagnosed using clinical indicators, according to the two prediction models. The importance of potential risk factors for sarcopenia was estimated by subtracting the predicted degrees of freedom from the partial χ2 statistic. Hazard rates of death were calculated using the hazard function and Cox regression analyses. RESULTS: We included 13 761 patients with cancer; the prevalence of sarcopenia was 33%. The median age was 58 y and 7135 patients (52%) were men. Patients with sarcopenia had a worse nutritional status and quality of life than those without sarcopenia. Age was the most important risk factor for sarcopenia compared with body mass index or TNM stage. Additionally, patients with sarcopenia had a significantly higher and earlier peak risk for mortality. After adjusting for baseline characteristics, sarcopenia was independently associated with mortality in the research population (hazard ratio, 1.429; P < 0.001) and most cancer types. CONCLUSION: Age is the most important risk factor for sarcopenia even in patients with cancer. Sarcopenia is strongly associated with a poor quality of life and reduced overall survival.

Comparison of laparoscopic and open radical gastrectomy for gastric cancer patients with GLIM-defined malnutrition.

PURPOSE: Malnutrition is common in the patients with gastric cancer. Radical gastrectomy remained the primary strategy of curable treatment for gastric cancer. This study is performed to explore the effect of laparoscopic radical gastrectomy on clinical outcomes in gastric cancer patients with malnutrition. METHODS: Gastric cancer patients with GLIM-defined malnutrition between 2014 and 2019 at our center were enrolled. The patients were divided into two groups according to the different type of surgery. Propensity score match analysis was used to balance the clinicopathologic characteristics of two groups. Postoperative outcomes and survival were compared. Multivariate analysis was used to independent risk factors of complication, overall survival (OS), and disease-free survival (DFS). RESULTS: Compared with patients underwent open radical gastrectomy, patients who underwent laparoscopic radical gastrectomy had lower rate of total, surgical and severe complications. They also had shorter postoperative hospital stay with better OS and DFS. Hypoalbuminemia (P = 0.003) was the independent risk factor of complications. Old age (≥75, P = 0.035) and TNM stage (III: P < 0.001, II: P = 0.015) were the independent risk factors of OS. Combined resection (P = 0.003) and TNM stage (III: P < 0.001, II: P = 0.001) posed independent risk factors of lacking DFS. Laparoscopic surgery proved to be the independent protective factor of complications (P = 0.014), OS (P < 0.001) and DFS (P < 0.001). CONCLUSION: Laparoscopic radical gastrectomy was relative safe and showed favorable outcomes in malnourished gastric cancer patients.

Regulation of muscle stem cell fate.

Skeletal muscle plays a critical role in human health. Muscle stem cells (MuSCs) serve as the major cell type contributing to muscle regeneration by directly differentiating to mature muscle cells. MuSCs usually remain quiescent with occasionally self-renewal and are activated to enter cell cycle for proliferation followed by differentiation upon muscle injury or under pathological conditions. The quiescence maintenance, activation, proliferation, and differentiation of MuSCs are tightly regulated. The MuSC cell-intrinsic regulatory network and the microenvironments work coordinately to orchestrate the fate transition of MuSCs. The heterogeneity of MuSCs further complicates the regulation of MuSCs. This review briefly summarizes the current progress on the heterogeneity of MuSCs and the microenvironments, epigenetic, and transcription regulations of MuSCs.

Coexistence of GLIM-defined malnutrition and sarcopenia have negative effect on the clinical outcomes in the elderly gastric cancer patients after radical gastrectomy.

Background: Malnutrition and sarcopenia are common in elderly gastric cancer patients, which are also interrelated and affect each other. We aimed to determine the characteristics of coexistence of malnutrition and sarcopenia in the elderly gastric cancer patients and investigate the predictive roles of malnutrition and sarcopenia on clinical outcomes. Methods: Between 2014 and 2019, a total of 742 elderly gastric cancer patients were enrolled. Malnutrition and sarcopenia were diagnosed according to the most recent diagnostic criteria. Patients were divided into four groups according to presence of these two symptoms. Clinical characteristics, short- and long-term outcomes were compared among four groups. The independent risk factors for complications and survival were evaluated using univariate and multivariate analyses. Results: Of all patients, 34.8% were diagnosed with malnutrition and 34.0% were diagnosed with sarcopenia. Patients with both malnutrition and sarcopenia had the highest rate of total (P < 0.001), surgical (P = 0.003), and medical complications (P = 0.025), and the highest postoperative hospital stays (P < 0.001) and hospitalization costs (P < 0.001). They also had the worst overall survival (P < 0.0001) and disease-free survival (P < 0.0001). Sarcopenia and Charlson Comorbidity Index (≥2) were independent risk factors for total complications. Hypoalbuminemia and malnutrition were non-tumor-related independent risk factors for overall survival and disease-free survival. Conclusions: Malnutrition and sarcopenia had superimposed negative effects on elderly gastric cancer patients. Preoperative geriatric evaluation including screening for malnutrition and sarcopenia are recommended for all elderly gastric cancer patients for accurate treatment strategy.

The landscape of aging.

Aging is characterized by a progressive deterioration of physiological integrity, leading to impaired functional ability and ultimately increased susceptibility to death. It is a major risk factor for chronic human diseases, including cardiovascular disease, diabetes, neurological degeneration, and cancer. Therefore, the growing emphasis on "healthy aging" raises a series of important questions in life and social sciences. In recent years, there has been unprecedented progress in aging research, particularly the discovery that the rate of aging is at least partly controlled by evolutionarily conserved genetic pathways and biological processes. In an attempt to bring full-fledged understanding to both the aging process and age-associated diseases, we review the descriptive, conceptual, and interventive aspects of the landscape of aging composed of a number of layers at the cellular, tissue, organ, organ system, and organismal levels.

Prognostic value of myosteatosis and sarcopenia for elderly patients with colorectal cancer: A large-scale double-center study.

BACKGROUND: Myosteatosis and sarcopenia are forms of muscle depletion that impair the normal physiological function of elderly patients, resulting in a worse prognosis. This study aimed to evaluate the prognostic value of sarcopenia and myosteatosis on postoperative outcomes in elderly patients with colorectal cancer. METHODS: From February 2015 to March 2021, a total of 921 elderly patients who underwent curative surgeries for colorectal cancer at 2 centers were enrolled and grouped by the presence of either myosteatosis or sarcopenia. Clinicopathological characteristics and postoperative outcomes were compared between the 2 groups. The independent risk factors for complications and overall survival were evaluated. RESULTS: Patients with myosteatosis had higher incidences of total and surgical complications, longer surgical duration, lower numbers of lymph nodes harvested, and longer postoperative hospital stays. Patients with sarcopenia had higher incidences of total complications, medical complications, and shorter surgical durations. Both conditions had adverse effects on overall survival and disease-free survival. Overweight status (P = .004), hypoalbuminemia (P < .001), myosteatosis, (P = .029) and sarcopenia (P = .017) were independent risk factors for total complications. Hypoalbuminemia (P = .035), myosteatosis (P = .003), sarcopenia (P = .027), and tumor-nodes-metastasis stage (≥Ⅲ; P < .001) were independent negative prognostic factors for overall survival. CONCLUSION: Myosteatosis and sarcopenia have different characteristics and are associated with poor prognoses in elderly patients with colorectal cancer. Myosteatosis occurs more frequently. Early diagnosis and intervention for myosteatosis should be included in preoperative management, which may improve prognosis in elderly patients.

Reference values of low body mass index, mid-upper arm circumference, and calf circumference in cancer patients: A nationwide multicenter observational study.

OBJECTIVE: Anthropometric measurements including body mass index (BMI), mid-upper arm circumference (MUAC), and calf circumference (CC) are simple and convenient indicators of nutritional status and muscle mass. However, most of their reference values come from studies based on healthy Western populations. The optimal reference values of these anthropometric factors in Asian patients with cancer are unclear. The aim of this study was to develop reference values of severely and moderately low BMI, MUAC, and CC by analyzing a large sample of patients with cancer from a nationwide population. METHODS: We conducted a retrospective analysis of 16 104 patients who were diagnosed with malignant diseases from June 2012 to January 2019. The median age of the patients was 58 y, and 52.5% were men. Optimal stratification was used to calculate reference values using X-tile software. Kaplan-Meier and multivariate Cox analysis were performed to analyze survival data. A receiver operating characteristic analysis was conducted to test the performance of new reference values in diagnosing malnutrition. RESULTS: The optimal reference values were calculated for BMI (moderately low: 19.7 [women] and 19 [men]; severely low: 16.7 [women] and 16.7 [men]), MUAC (moderately low: 24.5 [women] and 23.2 [men] severely low: 20.6 [women] and 19.4 [mnen]), and CC (moderately low: 29.1 [women] and 29.3 [men]; severely low: 26.7 [women] and 26.9 [men]). New reference values had more significant affects on mortality risk and better performance in predicting malnutrition than existing ones. CONCLUSIONS: The present study defined reference values of moderately and severely low BMI, MUAC, and CC, which showed strong associations with quality of life, malnutrition, and mortality risk. New reference values from the present study are classification references specifically for the Asian population, which is a new step to promote the application of Global Leadership Initiative on Malnutrition criteria and its severity grading system in Asia.

Development and validation of a Modified Patient-Generated Subjective Global Assessment as a nutritional assessment tool in cancer patients.

BACKGROUND: Completing Patient-Generated Subjective Global Assessment (PG-SGA) questionnaires is time consuming. This study aimed to develop and validate an easy-to-use modified PG-SGA (mPG-SGA) for cancer patients. METHODS: Seventy professionals assessed the content validity, comprehensibility, and difficulty of the full PG-SGA. A survey including the PG-SGA and other questionnaires was completed by 34 071 adult hospitalized cancer patients with first cancer diagnosis or recurrent disease with any tumour comorbidities from the INSCOC study. Among them, 1558 patients were followed for 5 years after admission. Reliability and rank correlation were estimated to assess the consistency between PG-SGA items and to select mPG-SGA items. The external and internal validity, test-retest reliability, and predictive validity were tested for the mPG-SGA via comparison with both the PG-SGA and abridged PG-SGA (abPG-SGA). RESULTS: After deleting items that more than 50% of professionals considered difficult to evaluate (Worksheet 4) and items with an item-total correlation <0.1, the mPG-SGA was constructed. Nutritional status was categorized using mPG-SGA scores as well-nourished (0 points) or mildly (1-2 points), moderately (3-6 points), or severely malnourished (≥7 points) based on the area under curve (0.962, 0.989, and 0.985) and maximal sensitivity (0.924, 0.918, and 0.945) and specificity (1.000, 1.000, and 0.938) of the cut-off scores. The external and internal validity and test-retest reliability were good. Significant median overall survival differences were found among nutritional status groups categorized by the mPG-SGA: 24, 18, 14, and 10 months for well-nourished, mildly malnourished, moderately malnourished, and severely malnourished, respectively (all Ps < 0.05). Neither the PG-SGA nor the abridged PG-SGA could discriminate the median overall survival differences between the well-nourished and mildly malnourished groups. CONCLUSIONS: We systematically developed and validated the mPG-SGA as an easier-to-use nutritional assessment tool for cancer patients. The mPG-SGA appears to have better predictive validity for survival than the PG-SGA and abridged PG-SGA.

Impact of sarcopenia on clinical outcomes of patients with stage I gastric cancer after radical gastrectomy: A prospective cohort study.

BACKGROUND: The relationships between sarcopenia and postoperative outcomes in patients with early-stage gastric cancer who undergo radical gastrectomy is unclear. We aimed to investigate the predictive value of sarcopenia on adverse outcomes for stage I gastric cancer. METHODS: The clinical data of patients who underwent radical gastrectomy for stage I gastric cancer between July 2013 and May 2019 were prospectively collected. Basic sarcopenia components were measured preoperatively. Univariate and multivariate analyses were conducted to evaluate the risk factors for short- and long-term outcomes. RESULTS: A total of 507 patients with early-stage gastric cancer were included in the study, and 73 (14.4%) patients were diagnosed as sarcopenia. Patients with sarcopenia had significantly higher incidence of postoperative complications (32.9% vs. 17.5%, P = 0.002), longer postoperative hospital stays (13 days vs. 12 days, P < 0.001), higher hospitalization costs (65210 yuan vs. 55197 yuan, P < 0.001) and one-year mortality (8.2% vs. 1.8%, P = 0.002). During the median follow-up time of 38.8 months, 12 (16.4%) patients dead in the sarcopenic group and 25 (5.8%) patients dead in the non-sarcopenic group. Sarcopenia was an independent risk factor for both short- and long-term clinical outcomes. Moreover, we found that low muscle quantity and low handgrip strength mediated the adverse impacts of sarcopenia on postoperative complications while low muscle quality mediated the adverse impacts of sarcopenia on overall survival. CONCLUSION: Sarcopenia was strongly associated with worse short- and long-term clinical outcomes in patients with stage I gastric cancer who undergo radical gastrectomy.

Cachexia Versus Sarcopenia in Clinical Characteristics and Prognostic Value After Radical Gastrectomy for Gastric Cancer: A Large-Scale Prospective Study.

BACKGROUND: Sarcopenia and cachexia are two predictors of adverse clinical outcomes, but they are partly overlapping. We aimed to compare the characteristics and prognostic value of cachexia and sarcopenia in patients after gastrectomy. METHODS: From 2014 to 2019, a total of 1215 gastric cancer patients were enrolled. Cachexia and sarcopenia were diagnosed according to the most recent consensus definitions. Baseline characteristics and clinical outcomes were compared between the two groups. Risk factors of survival were evaluated by Cox regression analysis. RESULTS: Of all patients, 26.5% were diagnosed with cachexia and 19.8% were diagnosed with sarcopenia. Sarcopenia was more prevalent in elderly patients, while cachexia was prone to occur in patients with TMN stage III. Survival curves showed that sarcopenia had adverse effects in patients with TMN stage I and II-III, while cachexia was only associated with poor survival at stages II-III. For the entire cohort, both cachexia and sarcopenia were adverse factors for prognosis. However, for stage I patients, sarcopenia was an independent predictor for overall survival (OS) (HR = 4.939, P < 0.001) and disease-free survival (DFS) (HR = 4.256, P < 0.001), but not cachexia; for stage II-III patients, cachexia was an independent predictor for OS (HR = 1.538, P < 0.001) and DFS (HR = 1.473, P = 0.001), but not sarcopenia. CONCLUSIONS: Sarcopenia and cachexia have different clinical characteristics and prognostic values. For patients with early stage gastric cancer, detection for sarcopenia was more meaningful than cachexia. However, the prognostic significance of cachexia exceeded sarcopenia in advanced cancer.

Comparisons and Impacts of the Basic Components of Sarcopenia Definition and Their Pairwise Combinations in Gastric Cancer: A Large-Scale Study in a Chinese Population.

Background and Aims: Sarcopenia is negatively associated with clinical outcomes. However, the definitions of sarcopenia are inconsistent across international consensuses. Thus, the purpose of this study is to compare the impact of the basic definition components of sarcopenia and their combinations in post-operative complications and overall survival, aiming to find the best sarcopenia definition to stratify the prognosis in an Asian population. Methods: A total of 1,307 patients who underwent curative surgery for gastric cancer from July 2014 to May 2019 were prospectively included. The basic sarcopenia components were measured pre-operatively, including low skeletal muscle mass index (LSMI), low skeletal muscle radiodensity (LSMD), low handgrip strength (LHGS), and low gait speed (LGS). Among them, LSMI and LSMD were measured using a CT post-processing software, LHGS was measured using an electronic hand dynamometer, and LGS was represented by a 6-m walk speed. Results: For the single basic component, the muscle function parameters (LHGS or LGS) but not the muscle composition parameters (LSMI or LSMD) showed associations with post-operative complications and mortality. For the combination of the basic combinations, all statistically significant combinations included at least one muscle function parameter. The combination of muscle composition (LSMI or LSMD) and muscle function (LHGS or LGS) had a significantly higher area under the curve in the prediction of post-operative complications compared with the combinations of two muscle function parameters (LSMI plus LSMD) or two muscle composition parameters (LHGS plus LGS). Conclusions: Compared with muscle composition parameters (LSMI and LSMD), muscle function parameters (LHGS and LGS) are better predictors of post-operative complications and overall survival, which should be considered as the principal determinant in the sarcopenia definition. The definition of sarcopenia consists of muscle function (LHGS or LGS) and muscle composition (LSMI or LSMD) separately, which is better than the combination of the two muscle function parameters (LHGS plus LGS) or two muscle composition parameters (LSMI plus LSMD).

Sarcopenia is a predictive factor of poor quality of life and prognosis in patients after radical gastrectomy.

BACKGROUND: Patients with gastric cancer often suffer from generalized and progressive reduction of skeletal muscle mass and strength, which negatively affects the quality of life (QOL). In this study, we explored the impact of sarcopenia on QOL and overall survival (OS). METHODS: From December 2015 to June 2017, 135 patients underwent radical gastrectomy at the First Affiliated Hospital of Wenzhou Medical University. Based on the diagnostic criteria of the Asian Working Group for Sarcopenia (AWGS), data including handgrip strength, 6-m gait speed and muscle mass were collected and analyzed. EORTC QLQ-C30 and EORTC QLQ-STO22 were used to evaluate the QOL before surgery, 1, 3 and 6 months after surgery. RESULTS: A total of 27 out of the 135 patients (20.00%) were diagnosed with sarcopenia. Compared with non-sarcopenia group, patients in sarcopenia group had a higher incidence of postoperative complications (14.80% vs. 40.70%, p = 0.003), and more hospitalization costs (p = 0.029). The scores of eating restriction (p = 0.026), anxiety (p = 0.045) and body image (p = 0.046) were significantly higher in sarcopenia group at postoperative 6 months. Besides, sarcopenia was an independent risk factor for global health status at 6 months after operation (OR: 2.881, 95% CI: 1.110-7.475, p = 0.030) and OS (HR: 3.140, 95% CI: 1.255-7.855, p = 0.014). Other factors, including tumor stage III and the postoperative complications, had negative influences on OS. CONCLUSION: Sarcopenia is a predictive factor of poor QOL and prognosis in patients with gastric cancer.