Progressive sarcopenia and myosteatosis predict prognosis of advanced HCC patients treated with immune checkpoint inhibitors.

Background: Immunotherapy stands as a pivotal modality in the therapeutic landscape for the treatment of advanced hepatocellular carcinoma, yet responses vary among patients. This study delves into the potential impact of sarcopenia, myosteatosis and adiposity indicators, as well as their changes during immunotherapy, on treatment response and prognosis in patients with advanced hepatocellular carcinoma treated with immune checkpoint inhibitors. Methods: In this retrospective analysis, 116 patients with advanced hepatocellular carcinoma receiving immune checkpoint inhibitors were recruited. Skeletal muscle, intramuscular, subcutaneous, and visceral adipose tissue were assessed by computed tomography at the level of the third lumbar vertebrae before and after 3 months of treatment. Sarcopenia and myosteatosis were evaluated by skeletal muscle index and mean muscle density using predefined threshold values. Patients were stratified based on specific baseline values or median values, along with alterations observed during the treatment course. Overall survival (OS) and progression-free survival (PFS) were compared using the log-rank test and a multifactorial Cox proportional risk model. Results: A total of 116 patients were recruited and divided into two cohorts, 81 patients for the training set and 35 patients for the validating set. In the overall cohort, progressive sarcopenia (P=0.021) and progressive myosteatosis (P=0.001) were associated with objective response rates, whereas progressive myosteatosis (P<0.001) was associated with disease control rates. In the training set, baseline sarcopenia, myosteatosis, and subcutaneous and visceral adipose tissue were not significantly associated with PFS and OS. In multivariate analysis adjusting for sex, age, and other factors, progressive sarcopenia(P=0.002) and myosteatosis (P=0.018) remained independent predictors of PFS. Progressive sarcopenia (P=0.005), performance status (P=0.006) and visceral adipose tissue index (P=0.001) were all independent predictors of OS. The predictive models developed in the training set also had good feasibility in the validating set. Conclusion: Progressive sarcopenia and myosteatosis are predictors of poor clinical outcomes in patients with advanced hepatocellular carcinoma receiving immune checkpoint inhibitors, and high baseline visceral adiposity is associated with a poorer survival.

The clinical significance of sarcopenia in patients with hepatocellular carcinoma treated with lenvatinib and PD-1 inhibitors.

Background and aim: Sarcopenia has gained considerable attention in the context of hepatocellular carcinoma, as it has been correlated with a poorer prognosis among patients undergoing sorafenib or lenvatinib treatment for hepatocellular carcinoma (HCC). The clinical significance of sarcopenia in first-line advanced HCC patients treated with lenvatinib and programmed death-1 (PD-1) inhibitors needs to be clarified. Methods: Sarcopenia was diagnosed using CT (Computed tomography) or MRI (Magnetic Resonance Imaging), with the psoas muscle index (PMI) as the surrogate marker. Patients were grouped based on sarcopenia presences, and a comparative analysis examined characteristics, adverse events, and prognosis. The Cox regression analysis was applied to identify independent prognostic factors for survival, while nomograms were constructed to predict 1-year survival. Results: Among 180 patients, 46 had sarcopenia. Patients with baseline sarcopenia demonstrated significantly inferior median progression-free survival (mPFS) (3.0 vs. 8.3 months) and median overall survival (mOS) (7.3 vs. 21.6 months). The same results for mPFS (3.3 vs. 9.2 months) and mOS (9.4 vs. 24.2 months) were observed in patients who developed sarcopenia after treatment. Furthermore, significantly higher grade 3 or higher adverse events (AEs) (73.91% vs 41.79%, p<0.001) were recorded in the sarcopenia group compared to the non-sarcopenia group. In the multivariate analysis, distant metastasis, elevated PLR and CRP levels, and low PMI remained independent predictive factors for poor OS. Additionally, skeletal muscle loss remained a significant independent risk factor for PFS. We developed a nomogram incorporating these four indicators, which predicted 12-month survival with a C-index of 0.853 (95% CI, 0.791 - 0.915), aligning well with actual observations. Conclusion: The prognosis of patients with HCC and sarcopenia is significantly worse when treated with lenvatinib and PD-1 inhibitors. The combination regimen of lenvatinib plus PD-1 inhibitors should be cautiously recommended due to the inferior prognosis and higher AEs.

Prevalence and clinical implications of sarcopenia in breast cancer: a systematic review and meta-analysis.

PURPOSE: The impact of sarcopenia in oncology is increasingly recognized, yet little is known about its clinical implications in breast cancer. This systematic review and meta-analysis estimates the overall prevalence of sarcopenia in breast cancer, quantifies skeletal muscle index (SMI), and comprehensively evaluates sarcopenia's impact on clinical outcomes. METHODS: We systematically searched primary original research published before June 2023 in four databases: the Cochrane Library via Wiley, CINAHL Plus with Full Text, Embase via Elsevier Excerpta Medica, and Medline via Ovid. Standardized mean SMI and 95% confidence interval (CI) were calculated by applying the random-effects model. The methodological quality of the included studies was assessed using the National Institutes of Health quality assessment checklist. RESULTS: The systematic review included 17 studies with a total of 9863 patients; the meta-analysis included 12 of these studies. The mean prevalence of sarcopenia in breast cancer (stages I-III) was 32.5%. The mean SMI assessed by CT was 43.94 cm2/m2 (95% CI 42.87, 45.01; p < .01). Overall, low muscle mass was associated with chemotherapy toxicities, dose reductions, dose delays, or treatment discontinuation. Low muscle mass was generally associated with poor survival, but in some studies, this association was not significant or reversed direction. CONCLUSION: Sarcopenia is not just a state of muscle mass loss, but an influencing factor on therapeutic effects and survival rates in oncology. It is thus necessary to recognize the risk of sarcopenia throughout the trajectory of cancer treatment, identify low muscle mass early, and manage it from a prehabilitation perspective.

[Research Progress in the Association Between Sarcopenic Obesity and Cancer].

As the global prevalence of obesity and the elderly population continues to increase,the incidence of sarcopenic obesity is also on the rise and becoming a global public health concern.Sarcopenic obesity not only increases the incidence of cancer,but is also associated with poor clinical outcomes in various cancers,such as surgical complications,increased risk of death,and possibly even an impact on chemotherapy as well.Therefore,sarcopenic obesity is emerging as an important indicator of prognosis in cancer patients.However,there are limited relevant studies on the association between sarcopenic obesity and cancer in China.This article reviews the definition and diagnosis of sarcopenic obesity,the clinical correlation between sarcopenic obesity and cancer,and the potential mechanisms,with a view to providing a reference for future clinical practice in China.

Sarcopenic Obesity Promotes Recurrence in Patients Undergoing Resection for Colorectal Liver Metastases (CRLM).

BACKGROUND/AIM: Sarcopenia, is predictive of a worse outcome after resection for colorectal liver metastases (CRLM). Obesity leads to a metabolic double burden if sarcopenia is as present, prompting malignancy progression, known as sarcopenic obesity (SO). This study aimed to compare sarcopenia and SO in patients undergoing CRLM resection, to prognostic parameters. PATIENTS AND METHODS: The skeletal muscle index (SMI) defined sarcopenia using sex specific cut off values (48.4 cm2/m2 for females and 59.1 cm2/m2 for males) by calculating the preoperative muscle mass at the vertebral height L3 using OSIRIX DICOM viewer. SO was determined as sarcopenia in patients showing obesity, as shown via fat percentage measurements on the preoperative CT scan. Established prognostic parameters (KRAS status, TNM classification, inflammatory response) were evaluated against SMI and SO to assess their predictability for postoperative outcomes. RESULTS: A total of 251 patients (62% female, median age 68 years) were included. Sarcopenic patients showed a threefold higher risk for postoperative death as compared to non-sarcopenic patients (p=0.04). Prevalent SO increased this risk to fivefold (p=0.01) compared to non-sarcopenic patients. COX regression analysis revealed SO and KRAS positivity as independent prognostic factors for disease-free survival (SO: p=0.038; KRAS: p=0.041; TNM, tumor size, Charlson Comorbidity Index, platelet-to-lymphocyte ratio, neutrophil-to-lymphocyte ratio all not significant). Patients risk of death in case of KRAS positivity and SO was seven times higher (p=0.03). CONCLUSION: There seems to be a benefit in merging data on mutational status and muscle wasting in patients with CRLM to facilitate an individual, patient-tailored approach.

Sarcopenia and Its Influencing Factors in Patients With Colorectal Cancer.

Sarcopenia can lead to more postoperative complications and poorer prognosis in patients with colorectal cancer; however there is limited research exploring the incidence and influencing factors of different stages of sarcopenia in patients with colorectal cancer. We investigated 312 patients with colorectal cancer. Sarcopenia was determined by measuring muscle mass, grip strength, and gait speed. According to the European Working Group on Sarcopenia in Older People (EWGSOP) 2010, patients were classified into four groups: nonsarcopenia, presarcopenia, sarcopenia, and severe sarcopenia. The incidence of sarcopenia and severe sarcopenia was 10.3% and 8.7%, respectively. Multivariate logistic regression analysis showed that age, TNM stage smoking history, total protein, upper arm circumference, waist circumference, and Patient-Generated Subjective Global Assessment (PG-SGA) score were independently associated with sarcopenia at different stages. This study suggests that routine data should be used to provide targeted care during hospitalization for patients with colorectal cancer in order to reduce the incidence of sarcopenia and improve prognosis.

Hepatocellular carcinoma and musculoskeletal system: A narrative literature review.

Musculoskeletal alterations in hepatocellular carcinoma (HCC) are less common than liver-related complications. However, they can significantly impact the quality of life and overall prognosis of patients with HCC. The main obstacle in the clinical assessment of HCC-induced musculoskeletal alterations is related to effective and timely diagnosis because these complications are often asymptomatic and unapparent during routine clinical evaluations. This narrative literature review aimed to provide a comprehensive overview of the contemporary literature related to the changes in the musculoskeletal system in patients with HCC, focusing on its clinical implications and underlying etiopathogenetic mechanisms. Osteolytic bone metastases are the most common skeletal alterations associated with HCC, which could be associated with an increased risk of low-trauma bone fracture. Moreover, previous studies reported that osteopenia, sarcopenia, and myosteatosis are associated with poor clinical outcomes in patients with HCC. Even though low bone mineral density and sarcopenia are consistently reported as reliable predictors of pretransplantation and post-transplantation mortality in HCC patients, these complications are frequently overlooked in the clinical management of patients with HCC. Taken together, contemporary literature suggests that a multidisciplinary approach is essential for early recognition and clinical management of HCC-associated musculoskeletal alterations to improve patient prognosis. Further research into the mechanisms and treatment options for musculoskeletal complications is warranted to enhance our understanding and clinical management of this aspect of HCC.

Emerging Therapeutic Strategies in Sarcopenia: An Updated Review on Pathogenesis and Treatment Advances.

Sarcopenia is a prevalent degenerative skeletal muscle condition in the elderly population, posing a tremendous burden on diseased individuals and healthcare systems worldwide. Conventionally, sarcopenia is currently managed through nutritional interventions, physical therapy, and lifestyle modification, with no pharmaceutical agents being approved for specific use in this disease. As the pathogenesis of sarcopenia is still poorly understood and there is no treatment recognized as universally effective, recent research efforts have been directed at better comprehending this illness and diversifying treatment strategies. In this respect, this paper overviews the new advances in sarcopenia treatment in correlation with its underlying mechanisms. Specifically, this review creates an updated framework for sarcopenia, describing its etiology, pathogenesis, risk factors, and conventional treatments, further discussing emerging therapeutic approaches like new drug formulations, drug delivery systems, stem cell therapies, and tissue-engineered scaffolds in more detail.

Combination of Parenteral Amino Acid Infusion and Intermittent Loading Exercise Ameliorates Progression of Postoperative Sarcopenia in Rat Model.

Postoperative sarcopenia is associated with poor outcomes in hospitalized patients. However, few studies have focused on short-term postoperative sarcopenia. Furthermore, the influence of nutritional management using amino acids (AAs) comprising a peripheral parenteral nutrition (PPN) solution and its combination with exercise (Exc) is unclear. Hence, we established a postoperative sarcopenic rat model to evaluate the effects of parenteral AA infusion combined with Exc on skeletal muscles and investigate the underlying mechanisms involved in the amelioration of muscle atrophy. Male F344 rats underwent surgery followed by hindlimb suspension (HS) for 5 days. The rats were divided into AA (-), AA (+), AA (-)-Exc, and AA (+)-Exc groups. They were continuously administered a PPN solution with or without AA at 98 kcal/kg/day. The Exc groups were subjected to intermittent loading for 1 h per day. Postoperative sarcopenic rats exhibited decreased muscle strength and mass and an upregulated ubiquitin-proteasome system, autophagy-lysosome system, and fast-twitch fiber-related genes, especially in the AA (-) group. The AA (+)-Exc group exhibited attenuated decreased muscle strength, increased gastrocnemius mass, and a suppressed upregulation of muscle atrophy- and fast-twitch fiber-related genes. Therefore, parenteral AA infusion combined with Exc may be effective in preventing postoperative sarcopenia in hospitalized patients.

Sarcopenia does not affect liver regeneration and postoperative course after a major hepatectomy. A prospective study on 125 patients using CT volumetry and HIDA scintigraphy.

BACKGROUND & OBJECTIVES: Sarcopenia is a morbi-mortality risk factor in digestive surgery, though its impact after major hepatectomy (MH) remains unknown. This prospective pilot study investigated whether volume and function of a regenerating liver is influenced by body composition. METHODS: From 2011 to 2016, 125 consecutive patients had computed tomography and 99mTc-labelled-mebrofenin SPECT-scintigraphy before and after MH at day 7 and 1 month for measurements of liver volumes and functions. L3 vertebra muscle mass identified sarcopenia. Primary endpoint was the impact of sarcopenia on regeneration capacities (i.e. volume/function changes and post-hepatectomy liver failure (PHLF) rate). Secondary endpoint was 3-month morbi-mortality. RESULTS: Sarcopenic patients (SP; N = 69) were significantly older than non-sarcopenic (NSP), with lower BMI and more malignancies, but with comparable liver function/volume at baseline. Postoperatively, SP showed higher rates of ISGLS_PHLF (24.6 % vs 10.9 %; p = 0.05) but with comparable rates of severe morbidity (23.2 % vs 16.4 %; p = 0.35), overall (8.7 % vs 3.6 %; p = 0.3) and PHLF-related mortality (8,7 % vs 1.8 %; p = 0.075). After matching on the extent of resection or using propensity score, regeneration and PHLF rates were similar. CONCLUSION: This prospective study using first sequential SPECT-scintigraphy showed that sarcopenia by itself does not affect liver regeneration capacities and short-term postoperative course after MH.

Impact of preoperative sarcopenia on postoperative complications and prognosis in patients undergoing robotic gastric cancer surgery: A propensity score matching study.

BACKGROUND: Sarcopenia, defined as decreased muscle mass and function, correlates with postoperative morbidity and mortality in cancer surgery. However, sarcopenia's impact specifically following robotic gastrectomy for gastric cancer has not been clearly defined. This study aimed to determine the influence of sarcopenia on short- and long-term clinical outcomes after robotic gastrectomy for gastric cancer. METHODS: This retrospective study analyzed 381 gastric cancer patients undergoing robotic gastrectomy. Sarcopenia was diagnosed by preoperative computed tomography (CT) body composition analysis. Propensity score matching created 147 pairs of sarcopenia and nonsarcopenia patients for comparison. Outcomes included postoperative complications, survival, inflammatory markers, length of stay, intensive care unit (ICU) transfer, and readmissions. RESULTS: Sarcopenia patients exhibited significantly higher rates of overall (53.7% versus 21.1%, P < 0.001), serious (12.9% versus 4.1%, P = 0.007), and grade III-IV complications compared to nonsarcopenia pairs after matching. Sarcopenia independently predicted reduced 3-years overall (HR = 2.53, 95% CI: 1.19-5.40, P = 0.016) and disease-free survival (HR = 1.99, 95% CI: 1.09-3.66, P = 0.026). Sarcopenia patients also showed heightened postoperative leukocyte, neutrophil, platelet, platelet to lymphocyte ratio (PLR), systemic immune-inflammation index (SII), and monocyte to lymphocyte ratio (MLR) levels alongside suppressed lymphocytes, monocytes, and neutrophil to lymphocyte ratio (NLR). CONCLUSION: Preoperative sarcopenia is correlated with increased postoperative complications and poorer long-term survival in gastric cancer patients undergoing robotic gastrectomy. Sarcopenia assessment can optimize preoperative risk stratification and perioperative management in this population.

Evaluating the influence of sarcopenia and myosteatosis on clinical outcomes in gastric cancer patients undergoing immune checkpoint inhibitor.

BACKGROUND: The development and progression of gastric cancer (GC) are closely linked to the nutritional status of patients. Although immunotherapy has been demonstrated to be clinically effective, the relationships of sarcopenia and myosteatosis with the use of immune checkpoint inhibitors (ICIs) in patients with gastric cancer remain to be characterized. AIM: To assess the effects of sarcopenia and myosteatosis on the clinical outcomes of patients with GC undergoing treatment with an ICI. METHODS: We performed a retrospective study of patients who were undergoing immunotherapy for GC. For the evaluation of sarcopenia, the optimal cut-off value for the skeletal muscle index was established using receiver operating characteristic analysis of data obtained from pre-treatment computed tomography images at the L3 vertebral level. Myosteatosis was defined using the mean skeletal muscle density (SMD), with a threshold value of < 41 Hounsfield units (HU) for patients with a body mass index (BMI) < 25 kg/m² and < 33 HU for those with a BMI ≥ 25 kg/m². The log-rank test was used to compare progression-free survival (PFS) and overall survival (OS), and a Cox proportional hazard model was used to identify prognostic factors. Nomograms were developed to predict the PFS and OS of patients on the basis of the results of multivariate analyses. RESULTS: We studied 115 patients who were undergoing ICI therapy for GC, of whom 27.4% had sarcopenia and 29.8% had myosteatosis. Patients with sarcopenia or myosteatosis had significantly shorter PFS and OS than those without these conditions. Furthermore, both sarcopenia and myosteatosis were found to be independent predictors of PFS and OS in patients with GC administering an ICI. The prediction models created for PFS and OS were associated with C-indexes of 0.758 and 0.781, respectively. CONCLUSION: The presence of sarcopenia or myosteatosis is a reliable predictor of the clinical outcomes of patients with GC who are undergoing treatment with an ICI.

A novel body composition risk score (B-Score) and overall survival among patients with nonmetastatic breast cancer.

BACKGROUND & AIMS: Measurements (amount, distribution, and radiodensity) of muscle and adipose tissue were reported to be individually associated with overall survival in patients with breast cancer. However, they were not typically combined to develop an overall risk score, which can identify patients at high risk of death and prioritize patients in need of dietary and lifestyle interventions. Thus, we aimed to develop a novel composite body composition risk score (B-Score). METHODS: We included 3105 patients with stage II or III breast cancer at Kaiser Permanente Northern California and Dana Farber Cancer Institute. From CT scans at diagnosis, we assessed areas and radiodensity of muscle and adipose tissue at the third lumber vertebrae. We considered skeletal muscle index (SMI), subcutaneous adipose tissue index (SATI) and SAT radiodensity as they were independent prognostic factors for overall survival. Each measurement was dichotomized using optimal stratification, with low SMI (<40.1 cm2/m2), high SATI (≥75.7 cm2/m2), and high SAT radiodensity (≥-97.2HU) considered risk factors. We calculated B-Score as the sum of these factors and estimated its association with overall survival using Cox proportional hazards regression with adjustment for clinicopathologic factors. RESULTS: Mean (standard deviation) age was 53.9 (11.8) years, 70.3% were Non-Hispanic White, and 60.5% were stage II. Most patients (60.6%) had only one body composition risk factor (B-Score = 1). Compared to those with no risk factors (B-Score = 0), the risk of death increased with more body composition risk factors: the adjusted hazard ratios were 1.10 (95% CI: 0.85, 1.42), 1.47 (95% CI: 1.12, 1.92), and 2.11 (95% CI: 1.26, 3.53) for B-Scores of 1, 2, and 3, respectively (Ptrend < 0.001). CONCLUSIONS: More unfavorable body composition characteristics were associated with increased risks of overall mortality in a dose-response manner. Considering body composition measurements together as a composite score (B-Score) may improve risk stratification and inform dietary and lifestyle interventions following breast cancer diagnosis.

Quantifying the severity of sarcopenia in patients with cancer of the head and neck.

BACKGROUND & AIMS: Existing skeletal muscle index (SMI) thresholds for sarcopenia are inconsistent, and do not reflect severity of depletion. In this study we aimed to define criterion values for moderate and severe skeletal muscle depletion based on the risk of mortality in a population of patients with head and neck cancer (HNC). Additionally, we aimed to identify clinical and demographic predictors of skeletal muscle depletion, evaluate the survival impact of skeletal muscle depletion in patients with minimal nutritional risk or good performance status, and finally, benchmarking SMI values of patients with HNC against healthy young adults. METHODS: Population cohort of 1231 consecutive patients and external validation cohorts with HNC had lumbar SMI measured by cross-sectional imaging. Optimal stratification determined sex-specific thresholds for 2-levels of SMI depletion (Class I and II) based on overall survival (OS). Adjusted multivariable regression analyses (tumor site, stage, performance status, age, sex, dietary intake, weight loss) determined relationships between 2-levels of SMI depletion and OS. RESULTS: Mean SMI (cm2/m2) was 51.7 ± 9.9 (males) and 39.8 ± 7.1 (females). The overall and sex-specific population demonstrated an increased risk of mortality associated with decreasing SMI. Sex-specific SMI (cm2/m2) depletion thresholds for 2-levels of muscle depletion determined by optimal stratification for males and females, respectively (male: 45.2-37.5, and <37.5; female: 40.9-34.2, and <34.2). In the overall population, Normal SMI, Class I and II SMI depletion occurred in 65.0%, 24.0%, and 11.0%, respectively. Median OS was: Normal SMI (114 months, 95% CI, 97.1-130.8); Class I SMI Depletion (42 months, 95% CI, 28.5-55.4), and Class II SMI Depletion (15 months, 95% CI, 9.8-20.1). Adjusted multivariable analysis compared with Normal SMI (reference), Class I SMI Depletion (HR, 1.49; 95% CI, 1.18-1.88; P < .001), Class II SMI Depletion (HR, 1.91; 95% CI, 1.42-2.58; P < .001). CONCLUSIONS: Moderate and severe SMI depletion demonstrate discrimination in OS in patients with HNC. Moderate and severe SMI depletion is prevalent in patients with minimal nutrition risk and good performance status. Benchmarking SMI values against healthy young adults exemplifies the magnitude of SMI depletion in patients with HNC and may be a useful method in standardizing SMI assessment.

Sarcopenia predicts short-term treatment-related toxicity in patients undergoing curative-intent therapy for head and neck cancer: A systematic review and meta-analysis.

Sarcopenia is an increasingly recognized biomarker associated with poorer outcomes. The objective of this study was to ascertain the effect of sarcopenia on treatment tolerance and short-term toxicity in head and neck cancer (HNC). A systematic review was performed using multiple databases. An inverse-variation, random-effects model was used to perform the meta-analysis to evaluate the effect of sarcopenia on severe treatment toxicity and poor treatment tolerance. Sixteen observational studies, including 3187 patients with HNC, were analyzed. The combined odds ratio (OR) for severe treatment toxicity and tolerance was 2.22 (95%CI 1.50-3.29) and 1.40 (95%CI 0.84-2.32), respectively. The effect of sarcopenia on short-term severe treatment toxicity was similar with upfront surgery (OR 2.03, 95%CI 1.22-3.37) and definitive radiotherapy (OR 2.24, 95%CI 1.18-4.27) Patients with sarcopenia are more than twice as likely to suffer a short-term treatment-related toxicity when undergoing curative-intent HNC treatment.

Long-term exposure to ambient air pollution with sarcopenia among middle-aged and older adults in China.

BACKGROUND: Few studies have examined the role of outdoor air pollution exposure in sarcopenia in Asia. We aimed to investigate the association of outdoor air pollutants exposure with sarcopenia among Chinese adults. METHODS: This nationally population-representative study used data from the China Health and Retirement Longitudinal Study (CHARLS) in 2015, 11,700 participants at least 45 years old from 125 Chinese cities were included. Sarcopenia status was identified according to the Asian Working Group for Sarcopenia 2019 (AWGS 2019) criteria. Ambient annual average air pollutants including fine particulate matter (PM2.5), inhalable particles (PM10), coarse particulate matter (PMcoarse), nitrogen dioxide (NO2), sulfur dioxide (SO2), and carbon monoxide (CO) were estimated by satellite models and ground-based measurements. Multinomial logistic regression models were performed to examine the associations of air pollutants exposure with different status of sarcopenia (including possible sarcopenia and sarcopenia). Stratified analyses were utilized to assess the effect modifiers. RESULTS: Among the 11,700 participants (52.6% women), the average age was 61.0 years. Each 10 µg/m3 increment of annual PMcoarse was associated with a higher risk of possible sarcopenia (odds ratio (OR) = 1.08, 95% confidence interval (CI) 1.04-1.11). Stratified analyses showed a positive risk of possible sarcopenia in women after exposure to PM10, PMcoarse, and NO2. Ambient NO2 exposure was positively associated with sarcopenia (OR = 1.13, 95% CI 1.04-1.22) in those aged 65 years and older. However, we have not observed differences by sex, age, residence, smoking, and drinking. Robustness results were found for PMcoarse in the sensitivity analyses. CONCLUSION: This nationwide study suggested that long-term exposure to outdoor air pollution, especially for PMcoarse, was associated with the risk of sarcopenia among Chinese adults. Our findings provide epidemiological implications for protecting healthy ageing by improving air quality.