Quantification of Scan Analysis Errors in GE Lunar DXA Visceral Adiposity in Adults

Validity and reliability of Gripwise digital dynamometer in the assessment of handgrip strength in older adults

Introduction

With the advancement of studies on the importance of sarcopenia in the aging process, new technologies have been developed to assess muscle mass and function. However, most research on portable devices has not considered a wide range of ages and clinical conditions. This study aimed to evaluate the reliability of the Gripwise digital dynamometer in measuring handgrip strength in older Brazilian adults, comparing its performance with the widely used Saehan device.

Methods

A cross-sectional study was conducted with 149 participants (32 men and 117 women), with an average age of 69.5 years. Handgrip strength was measured using both the Gripwise and Saehan dynamometers. Reliability was assessed using the intraclass correlation coefficient (ICC). Analyses considered three handgrip strength measurements from both devices, as well as the highest value obtained. The classification of dynapenia (low muscle strength) was compared using different cutoff points proposed by Villain et al. (2023), Spexoto et al. (2022), and Cruz-Jentoft et al. (2019).

Results

Both dynamometers demonstrated excellent reliability, with ICC values above 0.90. However, significant differences in mean handgrip strength values were observed between the devices (approximately 3.5-four kgf). These variations impacted the classification of dynapenia, with the Gripwise identifying more cases of low muscle strength compared to Saehan.

Conclusion

The lower values reported by the Gripwise may impact clinical decision-making in two ways. On one hand, lower values may lead to earlier detection of muscle weakness, allowing for quicker intervention in individuals with strength below typical thresholds. However, this could also result in an overestimation of the prevalence of dynapenia if the values do not accurately reflect true muscle strength, which could lead to unnecessary interventions. Therefore, it is crucial to consider the need for adjustments in the cutoff points when using Gripwise. These findings highlight the need to revise cutoff points for dynapenia classification, considering device variations and model differences in older age groups.

Intra- and inter-rater reliability of muscle and fat thickness measurements obtained using portable ultrasonography in older adults

BACKGROUND & AIMS

Ultrasonography (US) is a promising tool for assessing body composition, offering accuracy and accessibility. However, technician skills and equipment characteristics can impact measurement reliability. We aimed to evaluate the intra- and inter-rater reliability of two evaluators using A-mode Portable Ultrasound to measure muscle and fat thickness in Brazilian older adults.

METHODS

Quantitative cross-sectional study carried out with 150 community-dwelling older adults of Campinas-SP-Brazil, recruited in a retirement preparation program and a geriatric outpatient care unit. Scans of nine anatomical points were performed using the portable ultrasound in A-mode (BodyMetrix Pro System BX2000; Livermore, CA), with 6 scans per location and 3 measurements taken by each evaluator. After the selection and analysis of the generated images, muscle and fat thickness were measured. Reliability estimates between measures of the same evaluator (intra-rater) and between evaluators (inter-rater) were assessed using intraclass correlation coefficients (ICC), and differences within and between technicians were assessed using one-way ANOVA. Analyses were carried out for the overall sample and stratified by sex and by nutritional status.

RESULTS

Excellent ICC values (>0.90) were found for subcutaneous fat thickness in intra- and inter-rater reliability analyses. The lowest ICC values were observed for deep abdominal fat thickness measured by evaluator 1 (ICC = 0.90) and evaluator 2 (ICC = 0.87), as well as in the inter-rater analysis (ICC = 0.85). Muscle thickness measurements had satisfactory ICC values for triceps, biceps, anterior thigh, and calf, ranging from moderate to good (ICC 0.50-0.90).

CONCLUSION

A portable A-mode ultrasound demonstrates excellent reliability among both intra- and inter-raters for assessing fat thickness but only moderate for muscle thickness in older adults. Hence, this could prompt inquiries regarding the sole reliance on this tool for quantifying muscle mass and examining sarcopenia in older adults. To our knowledge, this study represents the first assessment of reliability for a portable A-mode ultrasound device conducted with older adults.

DXA reference values and anthropometric screening for visceral obesity in Western Australian adults

Limited reference values exist for visceral adipose tissue (VAT) mass measured by DXA. The objectives of this study were to provide reference values for DXA-derived VAT mass and compare the association with anthropometry measures. The study cohort comprised 677 men and 738 women aged 18–65 years from Western Australia. Whole-body scans using a GE Lunar iDXA and anthropometry measures were collected. Reference percentile data were stratified by sex and age. Correlation analysis compared DXA-derived and anthropometry variables. Specificity, sensitivity, and Youden’s Index were used to evaluate the ability of anthropometric thresholds to predict individuals with high VAT. In men, waist circumference (WC), waist-hip ratio, and waist-height ratio (WHtR) had ‘high’ correlations with VAT mass. In women, only WHtR was ‘highly’ correlated with VAT mass. Overweight thresholds for WC, along with a body mass index of 25.0 kg/m² in women, had the highest combination of sensitivity and specificity when using anthropometry measures to identify individuals with high VAT mass. We provide the first reference data sets for DXA-derived VAT mass among Western Australians. Excessive VAT mass may be identified in men using the overweight WC threshold and in women using both the overweight BMI and WC thresholds.