Estimating resting energy expenditure from dual‐energy X‐ray absorptiometry: A cross‐sectional study in healthy young adults

Abstract

Objective To qualify a 3C approach model of dual‐energy X‐ray absorptiometry (DXA) to estimate multicomponent resting energy expenditure (REE) referenced by indirect calorimetry (IC). Methods A sample of 155 college students, of both sexes (18‐30 years old) was evaluated. Anthropometric measures, REE by IC, and whole‐body DXA‐scans were performed. The REE for each body component was determined after transforming the components from the molecular (DXA) to the organ tissue level. Bland‐Altman and proportional bias analyses were used to verify agreement between REE measured (REEIC) and estimated (REEDXA). Results Statistically significant differences were found for all sex comparisons (P < .001), except for age (P = .950). Differences from the final sex‐specific models' were not found between REEIC and REEDXA (P > .05). Men also presented greater expenditure (P < .001) in each component, except for adipose tissue. The plots confirmed the validity of the model for both sexes, with low difference values between the measured and estimated REE. The mean of the differences of REEIC and REEDXA showed heteroscedasticity of the data for men (P = .004). The same error tendency was not evident for women (P = .333). Conclusions This 3C model, estimating REE from a multicomponent approach, allows a new application of DXA as tool for understanding intraindividual differences in terms of the mass of metabolically active tissue. Sex and populational differences should be taken in account. Consequently, we present qualified sex‐specific DXA models that can be applied in different contexts such as health and sports, besides considering interpersonal differences in terms of energy expenditure.

Association between classic and specific bioimpedance vector analysis and sarcopenia in older adults: a cross-sectional study

“…The calibration and measurements were following the manufacturer's instructions and were always carried out by the same technician. The examination was performed according to standardized procedures previously informed [ 28 , 29 ]. The DXA measurements included absolute and relative values (ALST and ALST%; FM and FM%; BMC and BMC%).…”

Multicompartment body composition analysis in older adults: a cross-sectional study

“…Among imaging analysis methods, dual energy X-ray absorptiometry (DXA) is widely used because its offers advantages such as low cost, speed of measurement (whole-body scans need less than 20 min), noninvasive, e ciency in the simultaneous determination of several components in a single scan (41), and their radiation exposure are considered small and safe for repeated measures (< 1 mrem for whole-body scans) (42). Furthermore, DXA is considered a 3-C model (43,44), once it can accurately measure FM, BMC, and appendicular lean soft tissue (ALST) (45). ALST is mainly muscle (≅ 76%) (46, 47) and a large proportion (≅ 74%) of SMM is in the extremities (8).…”