Can artificial intelligence simplify the screening of muscle mass loss?

Appendicular Skeletal Muscle Mass in Older Adults Can Be Estimated With a Simple Equation Using a Few Zero-Cost Variables

BACKGROUND AND PURPOSE

Assessing appendicular skeletal muscle (ASM) mass is crucial for the diagnosis of numerous pathologies related to the decline of muscle mass in old age, such as sarcopenia, malnutrition, or cachexia. The dual-energy X-ray absorptiometer (DEXA) radiological technique, which is the gold standard for its assessment, is particularly costly and not routinely used in clinical practice. The aim of this study was to derive computationally simple equations capable of estimating the DEXA-measured ASM at zero cost in older adult populations.

METHODS

We used the cross-sectional data collected by the National Health and Nutrition Examination Survey (NHANES) over 7 years (1999-2006). The study sample included 16,477 individuals aged 18 years and over, of which 4401 were over 60 years old. We considered 38 nonlaboratory variables. For the derivation of the equations, we employed the Brain Project, an innovative artificial intelligence tool that combines genetic programming and neural networks. The approach searches simultaneously for the mathematical expression and the variables to use in the equation. The derived equations are useful to estimate the DEXA-measured ASM.

RESULTS AND DISCUSSION

A simple equation that includes the body weight of the patient as the sole variable can estimate the outcome of DEXA with an accuracy equivalent to previously published equations. When used to identify individuals over 60 years old with muscle mass loss, it achieved an area under the curve (AUC) value of 0.85 for both males and females. The inclusion of sex and anthropometric data (thigh and arm circumference) improved the accuracy for male individuals (AUC 0.89). The model is also suitable to be applied to the general adult population of 18 years of age or older. Using more than 3 variables does not lead to better accuracy.

CONCLUSIONS

The newly proposed equations have better diagnostic accuracy than previous equations for the estimation of DEXA-measured ASM. They are readily applicable in clinical practice for the screening of muscle mass loss in the over 60-year-old population with nearly zero-cost variables. The most complex model proposed in this study requires only the inspection of a simple diagnostic chart to estimate the status of muscle mass loss.

Damage for gain: The useful damage of the Pitcher's paradox

Introduction

Sport-specific adaptations of the glenohumeral joint may arise in adolescent overhead athletes who begin high-performance sports early in life. Research mainly addresses overuse injuries, leaving gaps in prevention, with adults studied more than youths.

Objective

This study aims to investigate sport-adaptations of the glenohumeral joint in asymptomatic adolescent volleyball players to identify potential shoulder injury risk factors.

Design

Observational study.

Setting

Clinical screening campaign conducted at the Physical Medicine and Rehabilitation Unit of Policlinic Hospital in Catania, Italy.

Participants

Forty asymptomatic under-16 athletes were evaluated.

Interventions

Shoulder internal rotation (IR) and external rotation (ER), range of motion (ROM), total-rotation ROM, glenohumeral IR deficit (GIRD), general joint laxity using Beighton score, apprehension, relocation, O'Brian tests, and ultrasound (US) glenohumeral distance were tested bilaterally. Variables such as the player's position, the age they began the sport, limb dominance, weight, and height were also considered.

Results

The median US glenohumeral distance was at 0.42 ± 0.26 cm, which is consistent with the range found in non-dislocated shoulders of a healthy non-athletic population. The ER ROM was significantly greater in the dominant shoulder than the contralateral one (P = 0.0001), and there was a significant correlation between the ER ROM of attackers and their US glenohumeral distance (P = 0.0413). Furthermore, shoulder IR ROM and US glenohumeral distance were not significantly different between the dominant and contralateral limbs (P = 0.05). None of the athletes presented GIRD. Other tests, including the Beighton score, apprehension, and relocation tests, yielded no significant differences between the dominant and contralateral limbs.

Conclusions

Despite an increased shoulder ER in the dominant limb, the glenohumeral joint remains stable, suggesting that greater ROM in ER does not equate to instability in overhead athletes without hyperlaxity. Nevertheless, increased ER impacts glenohumeral distance in attacker volleyball players. This finding suggests that the shoulder morphological adaptation process starts early in attackers.

Multidisciplinary approach to sarcopenia: a narrative review

Sarcopenia is a condition in which muscle mass and strength are decreased and muscle function is impaired. It is an indicator of frailty and loss of independence in older adults. It is also associated with increased physical disability, which increases the risk of falls. As a multifactorial disease, sarcopenia is caused by a combination of factors including aging, hormonal changes, nutritional deficiencies, and physical inactivity. Understanding the underlying pathophysiology of sarcopenia and identifying its different causes is critical to developing effective prevention and treatment strategies. This review summarizes the pathophysiology, consequences, diagnostic methods, and multidisciplinary approaches to sarcopenia.