An older adult practices tai chi, representing accessible health monitoring.

Muscle Mass in Seniors: How Accurate Are Quick Body Scans?

Soraya Malik in Health & Wellness June 2025 • 4 min read.

"New research evaluates the reliability of bioimpedance analysis (BIA) for assessing muscle mass in older adults, offering insights into accessible health monitoring."

Maintaining muscle mass is crucial for the health and independence of older adults. Sarcopenia, the age-related loss of muscle mass and function, affects a significant portion of the geriatric population, leading to falls, disability, and reduced quality of life. Accurate and accessible methods for assessing muscle mass are essential for early diagnosis and intervention.

Dual-energy X-ray absorptiometry (DXA) is considered the gold standard for measuring muscle mass. However, DXA scans have limitations in terms of accessibility, cost, and portability, making them less feasible for widespread use. Bioimpedance analysis (BIA) emerges as a promising alternative. BIA is a quick, non-invasive, and relatively inexpensive technique that estimates body composition by measuring the resistance to a weak electrical current passing through the body.

Recent studies have developed BIA equations specifically designed for older adults to predict appendicular skeletal muscle mass (ASMM), which is the muscle mass in the limbs. However, questions remain about the accuracy of these equations, particularly in geriatric inpatients who often have multiple health conditions that could affect BIA readings.

BIA vs. DXA: Unpacking the Science of Muscle Measurement

An older adult practices tai chi, representing accessible health monitoring.

A recent study published in the journal Archives of Gerontology and Geriatrics investigated the performance of different single-frequency BIA (sfBIA) equations in comparison to DXA for quantifying appendicular muscle mass in geriatric inpatients. Researchers aimed to determine how well BIA could estimate muscle mass in this population and whether it could be a reliable tool for diagnosing sarcopenia.

The study involved 144 geriatric inpatients (86 women and 58 men) with a mean age of 80.7 years. Appendicular skeletal muscle mass was measured using DXA, and predicted using four different BIA equations (Kyle, Sergi, Scafoglieri, and Rangel Peniche). The results were then compared using statistical analysis to assess the agreement between BIA and DXA.

Regression Analysis: Showed only minor differences among the four BIA equations.
Mean Error: Significant differences were observed, highlighting variability in accuracy.
Scafoglieri Equation: Demonstrated the best performance overall, with agreement exceeding 83% with DXA.
Sensitivity: All BIA equations showed limited ability to detect reduced muscle mass.

The BIA equation developed by Scafoglieri et al. showed the best overall performance in geriatric inpatients, with an agreement of over 83% compared to DXA. This equation also had the lowest mean error, indicating that it was more accurate, on average, in estimating muscle mass. However, the study also found that all of the BIA equations had low sensitivity in detecting reduced muscle mass, meaning they were not very good at identifying individuals with sarcopenia.

The Future of Muscle Mass Assessment

The study suggests that BIA, particularly the Scafoglieri equation, can be a useful tool for estimating muscle mass in older adults, offering a more accessible and affordable alternative to DXA. While BIA shows promise, further research is needed to improve the accuracy of BIA equations and increase their sensitivity for detecting sarcopenia, potentially combining BIA with other clinical assessments to enhance diagnostic precision. It's a step forward in making muscle health monitoring more accessible, paving the way for earlier interventions and healthier aging.

About this Article -

This article was crafted using a human-AI hybrid and collaborative approach. AI assisted our team with initial drafting, research insights, identifying key questions, and image generation. Our human editors guided topic selection, defined the angle, structured the content, ensured factual accuracy and relevance, refined the tone, and conducted thorough editing to deliver helpful, high-quality information.See our About page for more information.

This article is based on research published under:

DOI-LINK: 10.1016/j.archger.2018.10.010, Alternate LINK

Title: Quantifying Appendicular Muscle Mass In Geriatric Inpatients: Performance Of Different Single Frequency Bia Equations In Comparison To Dual X-Ray Absorptiometry

Subject: Geriatrics and Gerontology

Journal: Archives of Gerontology and Geriatrics

Publisher: Elsevier BV

Authors: R. Reiter, B. Iglseder, W. Treschnitzer, R. Alzner, B. Mayr-Pirker, M. Kreutzer, C. Pirich, H. Kässmann, P. Dovjak, J. Reiss

Published: 2019-01-01

Everything You Need To Know

What is bioimpedance analysis, and why is it used?

Bioimpedance analysis (BIA) is a method used to estimate body composition by measuring the resistance to a weak electrical current as it passes through the body. It's significant because it offers a quick, non-invasive, and relatively inexpensive way to assess muscle mass, especially in older adults where maintaining muscle health is critical. The implications of BIA include its potential for widespread use in monitoring muscle mass, but it's important to note that its accuracy can vary, and it may not always be as precise as other methods like DXA scans.

What does appendicular skeletal muscle mass refer to, and why is it important to measure?

Appendicular skeletal muscle mass (ASMM) refers specifically to the muscle mass in the limbs, such as arms and legs. It is important because the loss of ASMM is a key indicator of sarcopenia, which is the age-related decline in muscle mass and function. Implications of accurately measuring ASMM include the ability to diagnose sarcopenia early, allowing for timely interventions to improve muscle health and overall quality of life in older adults. Measuring ASMM using methods like BIA helps determine the extent of muscle loss in the limbs.

What is a DXA scan, and why is it considered the gold standard?

Dual-energy X-ray absorptiometry (DXA) is a technique considered the gold standard for measuring body composition, including muscle mass. It is significant because it provides a highly accurate assessment of muscle mass, which is crucial for diagnosing conditions like sarcopenia. However, DXA scans have limitations in terms of accessibility, cost, and portability, making them less feasible for routine monitoring compared to other methods like BIA. The implications of DXA include its use as a reference standard for validating other muscle mass assessment techniques.

What is sarcopenia, and why should I be concerned about it?

Sarcopenia is the age-related loss of muscle mass and function. It is important because it can lead to falls, disability, reduced quality of life, and increased healthcare costs among older adults. The implications of sarcopenia include the need for early diagnosis and intervention strategies, such as exercise and nutrition, to maintain muscle health and independence. Methods like BIA and DXA are used to assess muscle mass and identify individuals at risk of sarcopenia.

What is the Scafoglieri equation, and why is it relevant?

The Scafoglieri equation is a specific formula used in bioimpedance analysis (BIA) to predict appendicular skeletal muscle mass (ASMM) in older adults. It is significant because studies have shown it to be more accurate than other BIA equations for estimating muscle mass in geriatric inpatients when compared to DXA measurements. Implications include its potential use in clinical settings as a reliable tool for assessing muscle mass, although its limitations in sensitivity for detecting reduced muscle mass need to be considered.