Evaluating Postoperative Muscle Strength Using Surface Electromyography in Hip Fracture Patient

Complementary combination of biomarkers for diagnosis of sarcopenia in C57BL/6J mice

AIMS

The objective of this study is to provide a reliable strategy for the diagnosis of sarcopenia based on a complementary combination of biomarkers from various approaches.

MATERIAL AND METHODS

A total of 30 C57BL/6J mice were used for the experiment, in which 15 young mice (YM) at 24 weeks old and 15 aged mice (AM) at 88 weeks old. Extracted features-based digital biomarkers from the electromyography activity of tibialis anterior muscles were evaluated by using receiver operating characteristic analysis. Extracted tissular proteins and circulating hormones based chemical biomarkers were investigated by using immunoblotting and enzyme-linked immunosorbent assay.

KEY FINDINGS

In terms of digital biomarkers, the feature-based classification of mice groups showed good performance (Feature A: AUC = 0.986, accuracy = 0.928) and (Feature B: AUC = 0.999, accuracy = 0.990). On the other hand, muscle-specific protein levels based chemical biomarkers (e.g. MuRF1, FoxO1, and perilipin2) were observed significantly increase with age. Pro-inflammatory cytokines based biomarkers extracted from muscle tissue and circulating plasma (e.g. TNF-α, IL-6, and IL-8) were significantly higher in case of AM group compared to YM group. Circulating hormone-based chemical biomarkers (e.g. cortisol/DHEA ratio and cathepsin D) presented a significant increase in concentrations with age. Circulating neurotransmitter based biomarkers (e.g. acetylcholine, serotonin, and histamine) also increased significantly in concentrations from YM to AM.

SIGNIFICANCE

A complementary combination of digital and chemical biomarkers covers multiple domains of sarcopenia to provide an effective strategy for the early diagnosis of sarcopenia.

Prevalence of sarcopenia and mortality rate in older adults with hip fracture

BACKGROUND

Several international study groups adopted appendicular skeletal muscle mass (ASM) index adjusted by (1) height squared, (2) weight, and (3) body mass index (BMI) in the diagnosis of sarcopenia. However, different prevalence rates of sarcopenia by each index and clinical implications were not well known. The purpose of this study was to compare the differences in (1) the percentage of sarcopenia in hip fracture patients and (2) the relative mortality rate according to the sarcopenia criteria of three ASM indices.

METHODS

Between January 2009 and December 2020, 1003 older adult hip fracture patients at a tertiary institution were eligible and retrospectively reviewed for this study. Based on the ASM measured on dual-energy X-ray absorptiometry, three indices were calculated, and sarcopenia was diagnosed. The proportion of sarcopenia was evaluated according to each index. One, two, and five-year mortality rates were compared between each sarcopenia group and a normal musculature group, based on ASM criteria.

RESULTS

The proportion of sarcopenia patients differed according to three ASM indices. The proportion of sarcopenic patients by ASM/height² index was higher than those of the other two indices in both male and female hip fracture patients. In male patients, 61% were sarcopenic by ASM/height² index, 37% by ASM/weight index, and 44% by ASM/BMI index. In female patients, 26%, 11%, and 14% were sarcopenic, respectively. Among the three indices, only ASM/height² had significant correlations with all 1-, 2-, and 5-year mortality rates.

CONCLUSIONS AND IMPLICATIONS

The prevalence of sarcopenia in hip fracture patients differed substantially according to ASM indices. Sarcopenic hip fracture patients had a higher mortality rate than those with normal musculature. The 1-year, 2-year, and 5-year mortality rates were discriminated by ASM/height² criteria in both men and women. Future prospective studies in a larger cohort are warranted.

Comparative Analysis of Supervised Classifiers for the Evaluation of Sarcopenia Using a sEMG-Based Platform

Sarcopenia is a geriatric condition characterized by a loss of strength and muscle mass, with a high impact on health status, functional independence and quality of life in older adults. To reduce the effects of the disease, just the diagnostic is not enough, it is necessary more than recognition. Surface electromyography is becoming increasingly relevant for the prevention and diagnosis of sarcopenia, also due to a wide diffusion of smart and minimally invasive wearable devices suitable for electromyographic monitoring. The purpose of this work is manifold. The first aim is the design and implementation of a hardware/software platform. It is based on the elaboration of surface electromyographic signals extracted from the Gastrocnemius Lateralis and Tibialis Anterior muscles, useful to analyze the strength of the muscles with the purpose of distinguishing three different “confidence” levels of sarcopenia. The second aim is to compare the efficiency of state of the art supervised classifiers in the evaluation of sarcopenia. The experimentation stage was performed on an “augmented” dataset starting from data acquired from 32 patients. The latter were distributed in an unbalanced manner on 3 “confidence” levels of sarcopenia. The obtained results in terms of classification accuracy demonstrated the ability of the proposed platform to distinguish different sarcopenia “confidence” levels, with highest accuracy value given by Support Vector Machine classifier, outperforming the other classifiers by an average of 7.7%.

Diagnosis and Management of Sarcopenia after Hip Fracture Surgery: Current Concept Review

To date, family medicine and internal medicine fields have been responsible for defining, researching, and development of treatments for sarcopenia, focusing mainly on diabetes and metabolic diseases. Therefore, application of current guidelines for diagnosis of sarcopenia which differ according to continent to patients with hip fractures in the orthopedic field is difficult. The purpose of this review was to understand the recent consensus on the definition and diagnosis of sarcopenia and to highlight the importance of research and future research opportunities on the management of sarcopenia in patients with hip fractures by orthopedic surgeons. The global prevalence of sarcopenia in patients with hip fractures is statistically significant. Despite establishment of various therapeutic and diagnostic criteria for osteoporosis in the clinical field, there are no clear, useful diagnostic criteria for sarcopenia in the clinical field. In particular, few studies on the evaluation and treatment of sarcopenia in patients with hip fractures have been reported. In addition, the quality of life of postoperative patients with hip fractures could be significantly improved by development of precise assessment for muscle regeneration and rehabilitation in the operating room.