A Cross-Sectional Study on Gluteal Muscles in Patients with Ankylosing Spondylitis at Different Stages of Hip Involvement

Hip involvement in ankylosing spondylitis (AS) is associated with severe functional impairment, and early diagnosis can improve the disease prognosis. We investigated gluteal muscle cross-sectional area (CSA) and radiodensity at different stages of hip involvement and their associations with AS-related clinical and laboratory parameters. This cross-sectional study included 83 patients with AS and 83 age- and sex-matched controls. Patients with AS were divided into three groups according to the Bath Ankylosing Spondylitis Radiology Hip Index system. The CSA and radiodensity of the gluteus maximus, medius, and minimus muscles were measured using computed tomography images. Muscle parameters were compared, and their relationships with clinical and laboratory parameters were evaluated. For the gluteus maximus, patients with AS had a lower CSA than controls, regardless of the degree of hip involvement. For the gluteus medius and minimus, patients with moderate/advanced hip involvement had significantly lower CSA and radiodensity than those with mild to no hip involvement. The severity of hip involvement was negatively associated with muscle parameters. CSA of the gluteus maximus decreased in early-stage hip involvement without any changes in radiographs, while radiodensity decreased in the later stages. Muscle parameters on computed tomography may be a more sensitive indicator than radiographic findings.

Skeletal Muscle Pathological Fat Infiltration (Myosteatosis) Is Associated with Higher Mortality in Patients with Cirrhosis

Myosteatosis (pathological fat accumulation in muscle) is defined by lower mean skeletal muscle radiodensity in CT. We aimed to determine the optimal cut-offs for myosteatosis in a cohort of 855 patients with cirrhosis. CT images were used to determine the skeletal muscle radiodensity expressed as Hounsfield Unit (HU). Patients with muscle radiodensity values below the lowest tertile were considered to have myosteatosis. Competing-risk analysis was performed to determine associations between muscle radiodensity and pre-transplant mortality. Muscle radiodensity less than 33 and 28 HU in males and females, respectively, were used as cut-offs to identify myosteatosis. In the univariate analysis, cirrhosis etiology, MELD score, refractory ascites, variceal bleeding, hepatic encephalopathy, sarcopenia and myosteatosis were predictors of mortality. Myosteatosis association with mortality remained significant after adjusting for confounding factors (sHR 1.47, 95% CI 1.17−1.84, p = 0.001). Patients with concurrent presence of myosteatosis and sarcopenia constituted 17% of the patient population. The cumulative incidence of mortality was the highest in patients with concomitant sarcopenia and myosteatosis (sHR 2.22, 95% CI 1.64−3.00, p < 0.001). In conclusion, myosteatosis is common in patients with cirrhosis and is associated with increased mortality. The concomitant presence of myosteatosis and sarcopenia is associated with worse outcomes.

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).

Muscle mass, not radiodensity, predicts physical function in cancer patients with or without cachexia

Background: There is a need to better understand the relationship between functional impairment and muscle mass in cancer cachexia. This study aimed to establish the relationship between computed tomography (CT)-derived muscle cross-sectional area (CSA), radiodensity, and skeletal muscle index (SMI) and dual energy X-ray absorptiometry (DXA) parameters with functional performance in cancer patients.

Materials and Methods: Handgrip strength, stair climb power (SCP), one-repetition maximum (1RM) strength, and body composition (CT and DXA) were compared across cancer patients with cachexia (CAC; N = 28), without cachexia (CNC; N = 28), and non-cancer patients (CON; N = 19). Multivariate regression was performed to find predictors of function.

Results: CAC had lower CT muscle CSA and SMI and lower DXA appendicular lean mass (ALM) than CNC or CON (p ≤ 0.011). Muscle radiodensity was not different across groups despite larger proportion of low CT SMI in CAC, and CAC performed worse in SCP than CON (p = 0.018). In cancer patients, DXA ALM and CT muscle CSA each predicted physical function (p ≤ 0.05); muscle radiodensity did not, and DXA ALM explained more variability in SCP and 1RM than CT muscle CSA.

Conclusions: Stair climb power was reduced in cancer cachexia; muscle radiodensity was not. Muscle mass by CT or DXA, but not radiodensity, predicted functional performance in cancer patients.

The association of medical and demographic characteristics with sarcopenia and low muscle radiodensity in patients with nonmetastatic colorectal cancer

BACKGROUND

Sarcopenia and low skeletal muscle radiodensity (SMD) have been associated with adverse outcomes in patients with colorectal cancer (CRC); however, factors contributing to these 2 muscle abnormalities are unclear.

OBJECTIVES

The aim of this study was to investigate the association of medical and demographic characteristics with muscle abnormalities among patients with nonmetastatic CRC.

METHODS

Patients with stage I-III invasive CRC (2006-11) who had diagnostic computed tomography (CT) available from Kaiser Permanente Northern California electronic medical records were included. CT-assessed sarcopenia and low SMD were defined according to optimal stratification. Logistic regressions including age, stage, site, total adipose tissue (TAT), race/ethnicity, neutrophil-lymphocyte ratio, smoking history, alcohol use, and Charlson Comorbidity Score were performed to identify characteristics associated with muscle abnormalities.

RESULTS

The study included 3262 patients (49.9% females) with a mean ± SD age of 62.6 ± 11.4 y. Sarcopenia and low SMD were highly prevalent (42.4% and 29.6%, respectively). Age and sex interactions were noted for muscle mass, but not SMD. Age was associated with higher odds of muscle abnormalities in a dose-response manner. Compared with those aged ≤50 y, patients aged 70-80 y had considerably higher odds (OR: 6.19; 95% CI: 4.72, 8.11) of sarcopenia, and low SMD (OR: 17.81; 95% CI: 11.73, 27.03). High TAT was related to a higher odds of low SMD (OR: 9.62; 95% CI: 7.37, 12.56), but lower odds of sarcopenia (OR: 0.59; 95% CI: 0.48, 0.71). Compared with Caucasians, African Americans had lower odds of sarcopenia and low SMD. Patients with a higher neutrophil-lymphocyte ratio had higher odds of having both muscle abnormalities. Patients who were smokers or had any comorbidity had higher odds of low SMD, but not sarcopenia.

CONCLUSIONS

Muscle abnormalities were common in patients with nonmetastatic CRC, with great variability in muscle mass and SMD across age, TAT, and race/ethnicity. Factors associated with muscle abnormalities may be used to facilitate risk stratification and the guidance of targeted strategies to counteract these abnormalities.

Muscle radiodensity and mortality in patients with colorectal cancer

BACKGROUND

Low skeletal muscle radiodensity (SMD) is related to higher mortality in several cancers, but the association with colorectal cancer (CRC) prognosis is unclear.

METHODS

This observational study included 3262 men and women from the Kaiser Permanente Northern California population diagnosed between 2006 and 2011 with AJCC stages I to III CRC. The authors evaluated hazard ratios (HRs) of low SMD for all-cause and CRC-specific mortality, assessed by computed tomography using optimal stratification, compared with patients with normal SMD. They also evaluated the cross-classification of categories of low versus normal SMD and muscle mass (MM) with outcomes.

RESULTS

The median follow-up was 6.9 years. Optimal stratification cutpoints for SMD were 32.5 in women and 35.5 in men. In multivariate-adjusted analyses, among patients with CRC, those with low SMD demonstrated higher overall (HR, 1.61; 95% confidence interval [95% CI], 1.36-1.90) and CRC-specific (HR, 1.74; 95% CI, 1.38-2.21) mortality when compared with those with normal SMD levels. Patients with low SMD and low MM (ie, sarcopenia) were found to have the highest overall (HR, 2.02; 95% CI, 1.65-2.47) and CRC-specific (HR, 2.54; 95% CI, 1.91-3.37) mortality rates.

CONCLUSIONS

In patients with CRC, those with low SMD were found to have elevated risks of disease-specific and overall mortality, independent of MM or adiposity. Clinical practice should incorporate body composition measures into the evaluation of the health status of patients with CRC. Cancer 2018;124:3008-15. © 2018 American Cancer Society.