Sarcopenia: Influence of Regional Skeletal Muscle Cutoff Points and Fat-Free Mass in Older Mexican People-A Pilot Study

Sarcopenia and sarcopenic obesity among community-dwelling Peruvian adults: A cross-sectional study

INTRODUCTION

Sarcopenia and sarcopenic obesity (SO) have emerged as significant contributors to negative health outcomes in the past decade. We aimed to estimate the prevalence of probable sarcopenia, sarcopenia, and SO in a community-dwelling population of 1151 adults aged ≥55 years in Lima, Peru.

METHODS

This cross-sectional study was conducted between 2018 and 2020. Sarcopenia was defined as the presence of low muscle strength (LMS) and low muscle mass (LMM) according to European (EWGSOP2), US (FNIH) and Asian (AWGS2) guidelines. We measured muscle strength by maximum handgrip strength and muscle mass using bioelectrical impedance analyzer. SO was defined as a body mass index ≥ 30 kg/m2 and sarcopenia.

RESULTS

The study participants had a mean age of 66.2 years (SD 7.1), age range between 60 to 92 years old, of which 621 (53.9%) were men. Among the sample, 41.7% were classified as obese (BMI ≥30.0 kg/m²). The prevalence of probable sarcopenia was estimated to be 22.7% (95%CI: 20.3-25.1) using the EWGSOP2 criteria and 27.8% (95%CI: 25.2-30.4) using the AWGS2 criteria. Sarcopenia prevalence, assessed using skeletal muscle index (SMI), was 5.7% (95%CI: 4.4-7.1) according to EWGSOP2 and 8.3% (95%CI: 6.7-9.9) using AWGS2 criteria. The prevalence of sarcopenia based on the FNIH criteria was 18.1% (95%CI: 15.8-20.3). The prevalence of SO, considering different sarcopenia definitions, ranged from 0.8% (95%CI: 0.3-1.3) to 5.0% (95%CI: 3.8-6.3).

CONCLUSION

Our findings reveal substantial variation in the prevalence of sarcopenia and SO, underscoring the necessity for context-specific cut-off values. Although the prevalence of SO was relatively low, this result may be underestimated. Furthermore, the consistently high proportion of probable sarcopenia and sarcopenia point to a substantial public health burden.

Assessment of the performance of the body mass index in diagnosing obesity in community-dwelling older adults in Latin American and Caribbean countries

BACKGROUND

The body mass index (BMI) ≥30 kg/m2 is the universally accepted cut-off point for defining obesity; however, its accuracy in classifying obesity in older adults is poorly understood.

OBJECTIVES

To assess the performance of the BMI cut-off point ≥30 kg/m2 in classifying obesity in older adults, using the fat mass index (FMI) and fat mass percentage (FM%) as reference criteria; and to establish region- and sex-specific BMI-based cut-off points to classify obesity in older adults.

METHODS

The present study is a secondary analysis derived from a cross-sectional project that included a sample of 1463 older adults from ten Latin American and Caribbean countries. Volunteers underwent total body water measurements using the deuterium dilution technique to determine FMI and FM%. Accuracy of the BMI and derived cutoff points was assessed by the area under the receiver operating characteristic curve (AUC).

RESULTS

The BMI cut-off point ≥30 kg/m2 had low sensitivity for classifying obesity in these older adults compared to the FMI and FM%. The AUC values for the optimal BMI-derived cut-off points showed an acceptable-to-outstanding discriminatory capacity in diagnosing obesity defined by the FMI. There was also a better balance between sensitivity and specificity than with the values obtained by a BMI ≥30 kg/m2 in older subjects in both regions.

CONCLUSION

The BMI cut-off point ≥30 kg/m2 had poor sensitivity for accurately diagnosing obesity in older adults from two regions. The region- and sex-specific BMI-derived cut-off points for defining obesity using the FMI are more accurate in classifying obesity in older men and women subjects from both regions.

Atoms for Nutrition: IAEA's Contribution to Tackling Malnutrition

Nuclear techniques, including stable isotope techniques, provide great potential for understanding nutrition and human health with better accuracy and precision compared with other routine techniques. The International Atomic Energy Agency (IAEA) has been at the forefront for more than 25 y to offer guidance and support on the use of nuclear techniques. This article demonstrates how the IAEA has enabled its Member States to contribute to good health and well-being in their countries and to assess progress toward achieving global nutrition and health targets to combat malnutrition in all its forms. Support is provided in several ways including research, capacity building, education, and training as well as the provision of guidance materials. The nuclear techniques help to objectively measure nutritional and health-related outcomes such as body composition, energy expenditure, nutrient uptake, and body stores and assess breastfeeding practices as well as environmental interactions. These techniques are continuously improved to make nutritional assessments more affordable and less invasive with wide use in field settings. New research areas are emerging to assess diet quality with changing food systems and to explore stable isotope-assisted metabolomics to address key questions on nutrient metabolism. Through a deeper understanding of mechanisms, nuclear techniques can contribute to eradicating malnutrition worldwide.

Optimal body composition indices cutoff values based on all-cause mortality in the elderly

The cutoffs of body composition indices are inconclusive in older populations. This study is designed toward determining the optimal cutoffs of the body composition indices based on the association with all-cause mortality. During 2009 and 2010, a cohort population of 1200 was enrolled in central western Taiwan. Of the 1200 subjects, 428 older subjects (mean age: 72.5 ± 5.4 yrs.; 47.7 % were women) were censored in this study. The waist circumference (WC) and body mass index (BMI) were measured using standard anthropometric methods. A multi-frequency bioelectrical impedance analysis device was utilized to estimate each participant's body composition indices, including percent body fat (PBF) and skeletal muscle mass index (SMMI). All claims records of death from 2009 to 2018 in the National Health Insurance Research Databank were identified. A receiver operating characteristic curve method and the highest Youden index were used to identify the optimal cutoffs. A Cox proportional hazards regression analysis was used to model associations between each of the recommended cutoff values with all-cause mortality. The all-cause mortality rate was 20.09 % after a follow-up period of 5.86 ± 2.39 person-years. The significant indices cutoff value was identified to be WC (86.7 cm) for older women and BMI (23.8 kg/m²) and as WC (77.6 cm), and SMMI (8.7 kg/m²) for older men. The recommended optimal cutoffs of the body composition indices were gender-specific and can be utilized to predict the risk of all-cause mortality.

Low appendicular skeletal muscle mass index is associated with the anthropometric variables of post-menopausal women

BACKGROUND

Skeletal muscle mass is a central component of body composition and its decline is enhanced during aging. We verified the association between the appendicular skeletal muscle mass index (ASMI) with the anthropometric variables, biochemical variables, and lifestyle of postmenopausal women.

METHODS

Cross-sectional observational study conducted with postmenopausal women. Sociodemographic, clinical, lifestyle, physical activity level, biochemical, and anthropometric markers were collected. Body composition was assessed by dual-energy densitometry. Multivariate logistic regression analysis was applied.

RESULTS

One hundred fourteen women aged in average 66.0 ± 5.8 years were evaluated. There was a significant association between ASMI and age (p = 0.004), body mass (p < 0.001), body mass index (BMI) (p < 0.001), adductor pollicis muscle thickness (APMT) (p < 0.001), plasma calcium levels (p = 0.003), calf circumference (CC), and waist circumference (WC) (p < 0.001 for both). Adjusted regression analyses revealed the influence of BMI, CC, and APMT in the 1st tertile of ASMI (p < 0.05), BMI and CC in the 2rd tertile of ASMI.

CONCLUSIONS

ASMI was associated with BMI and muscle mass reserve indicators such as CC and DAPMT. In clinical practice, this indicates that simple, low-cost measures with good applicability can be used to predict and track the risk of depletion of skeletal muscle mass and consequent sarcopenia.

The prevalence and risk factors of sarcopenia in rheumatoid arthritis patients: A systematic review and meta-regression analysis

BACKGROUND

Sarcopenia is an ever-increasingly recognized entity in aging or chronically-ill individuals. A recent surge of researches came out on sarcopenia in rheumatoid arthritis (RA). However, the results varied widely. We tried to assess the prevalence of and associated factors with sarcopenia in patients with RA.

METHODS

We searched the investigations dealing with the prevalence of and associated factors with sarcopenia in RA from PubMed, EMBASE, CENTRAL, EBSCOhost, Airiti Library, CEPS, CNKI and J-STAGE from the inception to January 11, 2020. Effects regarding prevalence and associated factors were extracted and evaluated by random-effects model. Sensitivity analysis was also performed.

RESULTS

Seventeen studies containing 3,140 RA subjects were identified. After exclusion of outliers, the pooled prevalence of sarcopenia was 31%. Neither ongoing-study districts nor diagnostic modalities affected prevalence significantly. Any associated factors being mentioned in at least two publications were analyzed, yielding functional limitation (Steinbrocker stage III/IV), high CRP and RF seropositivity as the significant risk factors. Based on disease durations, we carried out meta-regression and found DAS28 and HAQ are predictive models. There was no alteration in the interpretation of results from sensitivity analysis after removal of any studies skewed in sampling distribution.

CONCLUSIONS

The prevalence of sarcopenia in patients with RA is high, compared to that in general counterparts. Disease duration rather than age, residing area or diagnostic modalities influences sarcopenia development; DAS28 and HAQ predict occurrence. High index of suspicion to facilitate early detection of sarcopenia in RA patients is important.

lncRNA DLEU2 acts as a miR-181a sponge to regulate SEPP1 and inhibit skeletal muscle differentiation and regeneration

Sarcopenia is a serious public health problem associated with the loss of muscle mass and function. The purpose of this study was to identify molecular markers and construct a ceRNA pathway as a significant predictor of sarcopenia. We designed a prediction model to select important differentially expressed mRNAs (DEMs), and constructed a sarcopenia associated ceRNA network. After correlation analysis of each element in the ceRNA network based on clinical samples and GTEX database, C2C12 mouse myoblasts were used as a model to verify the identified ceRNA pathways. A new model for predicting sarcopenia based on four molecular markers SEPP1, SV2A, GOT1, and GFOD1 was developed. The model was used to construct a ceRNA network and showed high accuracy. Correlation analysis showed that the expression levels of lncDLEU2, SEPP1, and miR-181a were closely associated with a high risk of sarcopenia. lncDLEU2 inhibits muscle differentiation and regeneration by acting as a miR-181a sponge regulating SEPP1 expression. In this study, a highly accurate prediction tool was developed to improve the prediction outcomes of sarcopenia. These findings suggest that the lncDLEU2-miR-181a-SEPP1 pathway inhibits muscle differentiation and regeneration. This pathway may be a new therapeutic target for the treatment of sarcopenia.