Low muscle mass index is associated with type 2 diabetes risk in a Latin-American population: a cross-sectional study.

Objective: Diabetes mellitus is a growing disease with severe complications. Various scores predict the risk of developing this pathology. The amount of muscle mass is associated with insulin resistance, yet there is no established evidence linking muscle mass with diabetes risk. This work aims to study that relationship. Research methods and procedures: This cross-sectional study included 1,388 employees. The FINDRISC score was used to assess type 2 diabetes risk, and bioimpedance was used for body composition analysis. Appendicular skeletal muscle mass adjusted by body mass index (ASM/BMI) was analyzed. Sociodemographic, clinical and anthropometric measures were evaluated, logistic regression models with sex stratification were conducted and ROC curves were calculated to determine the ability of ASM/BMI index to predict T2D risk. Results: It was observed that patients with higher ASM/BMI had a lower FINDRISC score in both men and women (p < 0.001). A logistic regression model showed and association between ASM/BMI and diabetes risk in women [OR: 0.000 (0.000-0.900), p = 0.048], but not in men [OR: 0.267 (0.038-1.878), p = 0.185]. However, when the body mass index variable was excluded from the model, an association was found between muscle mass adjusted to BMI and diabetes risk in both men [OR: 0.000 (0.000-0.016), p < 0.001], and women [OR:0.001 (0.000-0.034), p < 0.001]. Other risk factors were having a low level of physical activity, waist circumference, age and sedentary lifestyle. A ROC curve was built and the optimal ASM/BMI cut-of value for predicting T2D risk was 0.82 with a sensitivity of 53.71% and specificity of 69.3% [AUC of 0.665 (0.64-0.69; p < 0.0001)]. Conclusion: When quantifying the risk of type 2 diabetes in both women and men, assessing muscle mass can help detect adult individuals with a high risk of developing type 2 diabetes.

Mid-arm muscle circumference cutoff points in patients with cirrhosis: Low muscle mass related to malnutrition predicts mortality.

OBJECTIVES: Muscle loss is one of the phenotypic criteria of malnutrition, is highly prevalent in patients with cirrhosis, and is associated with adverse outcomes. Mid-arm muscle circumference (MAMC) estimates the skeletal muscle mass and is especially helpful in cases of fluid overload. This study aimed to propose MAMC cutoff points for patients with cirrhosis and demonstrate its association with 1-year mortality. METHODS: This is an analysis of cohort databases from five reference centers in Brazil that included inpatients and outpatients with cirrhosis aged ≥18 y. The nutritional variables obtained were the MAMC (n = 1075) and the subjective global assessment (n = 629). We established the MAMC cutoff points stratified by sex based on the subjective global assessment as a reference standard for malnutrition diagnosis, considering the sensitivity, specificity, and Youden index. An adjusted Cox regression model was used to test the association of MAMC cutoff points and 1-year mortality. RESULTS: We included 1075 patients with cirrhosis, with a mean age of 54.8 ± 11.3 y; 70.4% (n = 757) male. Most patients had alcoholic cirrhosis (47.1%, n = 506) and were classified as Child-Pugh B (44.7%, n = 480). The MAMC cutoff points for moderate and severe depletion were ≤21.5 cm and ≤24.2 cm; ≤20.9 cm and ≤22.9 cm for women and men, respectively. According to these cutoff points, 13.8% (n = 148) and 35.1% (n = 377) of the patients had moderate or severe MAMC depletion, respectively. The 1-year mortality rate was 17.3% (n = 186). In the multivariate analysis adjusted for sex, age, MELD-Na, and Child-Pugh scores, a severe depletion in MAMC was an independent increased risk factor for 1-year mortality (HR: 1.71, 95% CI: 1.24-2.35, P < 0.001). Each increase of 1 cm in MAMC values was associated with an 11% reduction in 1-year mortality risk (HR: 0.89, 95% CI: 0.85-0.94, P < 0.001). CONCLUSIONS: Low MAMC classified according to the new cutoff points predicts mortality risk in patients with cirrhosis and could be used in clinical practice.

Examining the mediating role of muscle quantity in adolescents: associations with adiposity, cardiorespiratory fitness, muscular fitness, and cardiometabolic risk factors.

The aim of this study was to evaluate the mediation role of muscle quantity in the relationship between physical fitness and cardiometabolic risk factors (CMRF) in adolescents. This cross-sectional study conducted with 120 adolescents of both sexes, aged between 10 and 17 years. Body mass, height, fat mass (FM), lean mass, blood pressure, high-density lipoprotein, low-density lipoprotein, triglycerides, glucose, insulin, cardiorespiratory fitness (CRF) and 1 repetition maximum strength (1-RM) with evaluation of the leg press 45° (RM-leg), bench press (RM-bench) and arm curl (RM-arm). Body mass index z-score, appendicular skeletal muscle mass, appendicular skeletal muscle mass index, lean mass index (LMI), muscle-to-fat ratio (MFR), age at peak height velocity, and CMRF z-score were calculated. The direct relation between FM and CMRF was mediated by the LMI (26%) and inverse relation between CRF and CMRF was mediated by the LMI (26%). For girls, the direct relation between FM and CMRF was mediated by the LMI (32%); the inverse relation between CRF, RM-leg, RM-arm and CMRF was mediated by the LMI (32%, 33%, and 32%, respective). For boys, the indirect effect was not significant, indicating that LMI is not a mediator in the relation between FM, CRF, 1-RM with CMRF. The direct relation between RM-leg and CMRF was mediated by the MRF (16%). This finding evidenced the importance of promoting a healthy lifestyle to improve physical fitness levels and the quantity of muscle mass in adolescents.

Comparative assessment of abdominal and thigh muscle characteristics using CT-derived images.

OBJECTIVES: The aim of this study was to compare the assessment of skeletal muscle area (SMA in cm²), skeletal muscle index (SMI in cm²/m²), and skeletal muscle density (SMD in HU) between third lumbar vertebra (L3) and thigh landmarks, and the agreement in diagnosing low muscle mass and low SMD (L3 as the reference method). METHODS: This was a multicenter, cross-sectional study including healthy individuals (≥18 y of age) of both sexes, who had an elective computed tomography exam including abdominal and pelvic regions. Computed tomography images were analyzed to evaluate SMA, SMI, and SMD. Muscle abnormalities (low SMA, SMI, and SMD) were defined as values below the fifth percentile from a subsample of healthy young individuals (n = 111; 18-39 y of age; 55.9% women). Correlation coefficients, Bland-Altman graphs, and receiver operating characteristic (ROC) curves were calculated for the total sample and stratified by sex and age. RESULTS: In all, 268 individuals (44.3 ± 15.2 y of age) were evaluated (53% women). Significant (P < 0.001 for all analysis) and strong correlations between SMA (r = 0.896), SMI (r= 0.853), and SMD (r= 0.864) compared with L3 and thigh landmarks were observed. For the ROC curves, similar areas under the curve values were obtained for men (0.981), women (0.895), younger (0.902), and older adults (0.894). CONCLUSIONS: Muscle characteristics between L3and thigh landmarks have a strong correlation. This suggests that images of the thigh can be used to characterize muscle characteristics. Image acquisition and analysis of thigh region is simpler, with less radiation exposure, and consequently more appropriate for longitudinal analysis.

Transcriptomic analysis of elderly women with low muscle mass: association with immune system pathway.

Despite the well-established association of gene expression deregulation with low muscle mass (LMM), the associated biological mechanisms remain unclear. Transcriptomic studies are capable to identify key mediators in complex diseases. We aimed to identify relevant mediators and biological mechanisms associated with age-related LMM. LMM-associated genes were detected by logistic regression using microarray data of 20 elderly women with LMM and 20 age and race-matched controls extracted from our SPAH Study (GSE152073). We performed weighted gene co-expression analysis (WGCNA) that correlated the identified gene modules with laboratorial characteristics. Gene enrichment analysis was performed and an LMM predictive model was constructed using Support Vector Machine (SVM). Overall, 821 discriminating transcripts clusters were identified (|beta coefficient| >1; p-value <0.01). From this list, 45 predictors of LMM were detected by SVM and validated with 0.7 of accuracy. Our results revealed that the well-described association of inflammation, immunity and metabolic alterations is also relevant at transcriptomic level. WGCNA highlighted a correlation of genes modules involved in immunity pathways with vitamin D level (R = 0.63, p = 0.004) and the Agatston score (R = 0.51, p = 0.02). Our study generated a predicted regulatory network and revealed significant metabolic pathways related to aging processes, showing key mediators that warrant further investigation.

Sarcopenia predicts worse postoperative outcomes and decreased survival rates in patients with colorectal cancer: a systematic review and meta-analysis.

PURPOSE: Previous studies have shown an association of sarcopenia with adverse short- and long-term outcomes in multiple gastrointestinal cancer types. We aimed to investigate the prognostic value of sarcopenia on the postoperative outcomes and survival rates of patients with colorectal cancer (CRC). METHODS: A systematic literature search was performed using the PubMed, Embase, Cochrane, Google Scholar, and Scopus databases. We included studies that compared postoperative outcomes or survival rates in sarcopenic and non-sarcopenic patients with CRC. RESULTS: A total of 44 observational studies, comprising 18,891 patients, were included. The pooled prevalence of sarcopenia was 37% (n = 7009). The pooled analysis revealed an association between sarcopenia and higher risk of total postoperative complications (23 studies, OR = 1.84; 95% CI 1.35-2.49), postoperative severe complications (OR = 1.72; 95% CI 1.10-2.68), postoperative mortality (OR = 3.21; 95% CI 2.01-5.11), postoperative infections (OR = 1.40; 95% CI 1.12-1.76), postoperative cardiopulmonary complications (OR = 2.92; 95% CI 1.96-4.37), and prolonged length of stay (MD = 0.77; 95% CI 0.44-1.11) after colorectal cancer surgery. However, anastomotic leakage showed comparable occurrence between sarcopenic and non-sarcopenic patients (OR = 0.99; 95% CI 0.72 to 1.36). Regarding survival outcomes, sarcopenic patients had significantly shorter overall survival (25 studies, HR = 1.83; 95% CI = 1.57-2.14), disease-free survival (HR = 1.55; 95% CI = 1.29-1.88), and cancer-specific survival (HR = 1.77; 95% CI 1.40-2.23) as compared with non-sarcopenic patients. CONCLUSION: Among patients with colorectal cancer, sarcopenia is a strong predictor of increased postoperative complications and worse survival outcomes.

Risk Factors for Low Muscle Mass in a Population-based Prospective Cohort of Brazilian Community-dwelling Older Women: The São Paulo Ageing & Health (SPAH) Study.

INTRODUCTION: Sarcopenia is characterized by progressive loss of skeletal muscle mass, which results in decreased muscle strength, functional impairment, and increased risk of death. Few studies have performed a concomitant evaluation of clinical, laboratory, and body composition variables to accurately determine the contribution of each parameter to low muscle mass (LMM) in older subjects. This study aimed to identify risk factors (clinical, laboratory parameters, BMD, and body composition by DXA including visceral fat) for LMM in a prospective cohort of older Brazilian women. METHODS: A total of 408 women aged ≥65 yr from the São Paulo Ageing & Health study were evaluated with clinical data, laboratory bone tests, BMD, and body composition by DXA using Hologic QDR 4500A equipment. Risk factors were measured at baseline (2005-2007). After a follow-up of 4.3 ± 0.8 yr, subjects were classified according to the LMM definition of the Foundation for the National Institutes of Health criteria. LMM was defined when appendicular lean mass divided by body mass index was less than 0.512. Multivariate logistic regression models were used to identify independent risk factors for LMM. RESULTS: At the end of follow-up, 116 women (28.4%) had LMM. Age averages were 73.3 ± 4.9 yr in the LMM group and 72.5 ± 4.5 yr in the normal group (p = 0.11). Mean BMI was 30.6 ± 5.2 kg/m2 in the LMM group and 28.1 ± 4.7 kg/m2 in the normal group (p < 0.001). In multivariate analyses, predictors of LMM were: falls (OR = 1.14, p = 0.016), TSH levels (OR = 1.08, p = 0.018, per 1 µUI/L-increase), serum creatinine levels (OR = 11.11, p < 0.001, per 1 mg/dL-decrease), and visceral adipose tissue (VAT) mass (OR = 1.17, p < 0.001, per 100 g increase). CONCLUSIONS: Falls, high TSH, low creatinine, and high VAT were risk factors for LMM in older women. More attention should be paid to these factors, since they are potentially reversible with adequate intervention.

Relationship Between Skeletal Muscle Mass Indexes and Muscular Function, Metabolic Profile and Bone Mineral Density in Women with Recommendation for Bariatric Surgery.

BACKGROUND AND AIM: We evaluated low skeletal muscle mass (LMM) in women prior to bariatric surgery (BS) through different skeletal muscle mass indexes (MMIs) regarding body fat percentage (BFP), handgrip strength (HS), six-minute walk test (6MWT), metabolic profile and bone mineral density (BMD). METHODS: Women (n=62) were allocated into two groups according to LMM: obesity with low muscle mass (OLMM) or obesity with normal muscle mass (ONMM). LMM was defined by the appendicular skeletal muscle mass (ASM) adjusted for weight (ASM/wt × 100) and ASM adjusted for body mass index (ASM/BMI), considering the lowest quintile of the indexes studied. RESULTS: OLMM was found in 30.5% by ASM/wt × 100 and 20.3% by ASM/BMI. Using the ASM/wt × 100, OLMM group had a high BFP, low HS and BMD in L1-L4, femoral neck (FN) and total femur (TF) when compared with ONMM (p < 0.05). Using ASM/BMI, OLMM group had increased BFP, reduced HS and 6MWT in comparison to ONMM (p < 0.05). Metabolic profile was similar between OLMM and ONMM groups by the two MMIs. MMIs were negatively correlated with BFP (p < 0.05) and positively correlated with HS (p < 0.05), and none of them with 6MWT (p > 0.05). ASM/wt × 100 was positively correlated with all BMD sites assessed (p < 0.05). There was positive correlation between ASM/wt × 100 and ASM/BMI. CONCLUSION: OLMM identified by the ASM/wt × 100 and ASM/BMI had higher adiposity and lower HS. Using ASM/BMI, we found that OLMN had a poor physical performance, while the ASM/wt × 100 identified a lower BMD at all sites.

A simple anthropometric tool for the assessment of pre-sarcopenia in postmenopausal women.

OBJECTIVES: The purpose of this research was to explore the performance of anthropometric tools in the assessment of low muscle mass in a group of postmenopausal women. METHOD: Fifty consecutive ambulatory postmenopausal women were studied. A complete clinical examination and an anthropometric evaluation following a standardized procedure were performed. Three indicators were devised: upper limb adjusted perimeter (ULAP), lower limb adjusted perimeter (LLAP), and appendicular adjusted perimeter (AAP). RESULTS: Sixteen sarcopenic patients (32%) were identified using the DXA appendicular lean mass/h2 threshold. ULAP and AAP correctly classified 82% of the patients, while LLAP showed a lower performance (72%). The sensitivity and specificity values of ULAP and AAP were higher than those obtained using LLAP; their positive and negative predictive values were 65.2%, 96.3% and 68.4%, 90.3%, respectively. A highly significant concordance was observed for the three anthropometric indicators. CONCLUSION: The availability of reliable and simple clinical instruments to identify low muscle mass is of great relevance. Anthropometric methods reported in this paper could represent an innovative resource for muscle mass assessment in daily practice. The contribution of these approaches in the detection and management of sarcopenia should allow the physician to make early interventions and thus prevent or modify its relevant health consequences.