Abstract
Introduction:Dual energy X-ray absorptiometry (DXA) is widely used for the assessment of lean mass (LM), fat mass (FM) and bone mineral content (BMC). When observing standardised protocols, DXA has a high level of precision for the assessment of total body composition, including the head region. However, including the head region may have limited relevance in athletes and can be problematic when positioning taller athletes who exceed scan boundaries. This study investigated the precision of a new total-body-less-head (TBLH) DXA scan for three-compartment body composition measurement in athletes, with outcomes compared to the standard total-body DXA scan. Methods: Precision errors were calculated from two consecutive scans with re-positioning (Lunar iDXA, GE Healthcare, Madison, WI), in male and female athletes from a range of sports. TBLH precision was determined from repeat scans in 95 athletes (male n = 55; female n = 40; age: 26.0 ± 8.5 y; body mass: 81.2 ± 20.5 kg; stature: 1.77 ± 0.11 m), and standard total-body scan precision was derived from a sub-sample of 58 athletes (male n = 19; female n = 39; age: 27.6 ± 9.9 y; body mass: 69.6 ± 14.8 kg; stature: 1.72 ± 0.94 m). Data from the sub-sample were also used to compare precision error and 3-compartment body composition outcomes between the standard total-body scan and the TBLH scan. Results:: TBLH precision errors [root mean squared-standard deviation, RMS-SD (coefficient of variation, %CV)] were bone mineral content (BMC): 15.6 g (0.5%), lean mass (LM): 254.3 g (0.4%) and fat mass (FM): 199.4 g (1.3%). These outcomes compared favourably to the precision errors derived from the standard total-body scan [BMC: 12.4 g (0.4%), LM: 202.2 g (0.4%), and FM: 160.8 g (1.1%)]. The TBLH scan resulted in lower BMC (-19.5%), LM (-6.6%), and FM (-4.5%) compared to the total-body scan (BMC: 2,308 vs. 2,865 g; LM: 46,954 vs. 50,276 g; FM: 15,183 vs. 15,888 g, all p<0.005). ConclusionThe TBLH scan demonstrates high in-vivo precision comparable to that of the standard total-body scan in a heterogeneous cohort of athletes. Given the impact of head exclusion on total body composition outcomes, TBLH scans should not be used interchangeably with the standard total-body scan.
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Disclaimer: All third-party content on this website/platform is and will remain the property of their respective owners and is provided on "as is" basis without any warranties, express or implied. Use of third-party content does not indicate any affiliation, sponsorship with or endorsement by them. Any references to third-party content is to identify the corresponding services and shall be considered fair use under The CopyrightLaw.