Table 2 Statements from the Official Position of the Brazilian Association of Bone Assessment and Metabolism (ABRASSO) regarding the clinical application of body composition measurements using dual-energy x-ray absorptiometry (DXA), along with the levels of agreement (interrater reliability) among the statement’s collaborators
Question | Statement | Level of agreement (%) |
|---|---|---|
1. What are the validated criteria for bone mass assessment? | The WHO criteria for densitometric osteoporosis only apply to the skeletal sites of the proximal femur (femoral neck and total hip), lumbar spine (L1–L4), and 33% radius. The only exception is the use of total body less head (TBLH) bone mass Z-score values as a diagnostic criterion of low bone mass in pediatric patients, with an adopted cutoff value of − 2.0 standard deviations (SDs) of the mean value obtained from individuals of the same age. The NHANES III reference database for total body BMC should be adopted when DXA is used for body composition assessment in children Body composition DXA reports regarding bone mass should include: BMC results (in grams); BMD values (in g/cm2) and Z-scores (SDs) should be reported for adults, but without establishing a diagnosis of osteopenia or osteoporosis. For individuals with Z-score values below − 2.0 SD, the sentence “low bone mass for age” may be reported; TBLH and Z-scores should be reported in children and adolescents | 96.7 |
2. What are the criteria for assessing fat mass? | Recommendations for assessment of fat mass include the fat mass index (FMI; in kg/m2), interpreted according to the NHANES III cutoff values, the estimated abdominal visceral adipose tissue (VAT; in g/cm3 if assessed with a GE-Lunar device or g/cm2 if assessed with a Hologic device), and the android-to-gynoid (A/G) fat ratio | 95.7 |
3. What are the validated criteria for assessing lean mass? | Several validated criteria are available for assessing appendicular lean mass using DXA, including the Baumgartner criteria, the Newman criteria, and the Foundation for the National Institutes of Health (FNIH) Sarcopenia Project criteria Lean mass can also be assessed using muscle strength parameters, including dynamometry and indirect and dynamic physical fitness and functional capacity tests evaluating static and dynamic balance, mobility, and flexibility, such as the chair-stand test and isokinetic chair | 90.7 |
4. Which parameters should be included in the DXA body composition report? | For adults older than 20 years, report whole-body (including head) values of: Anthropometry: weight (kg), height (m), and BMI (kg/m2) Bone mass compartment: BMD (g/cm2), BMC (g), and Z-score (in SDs) Fat mass compartment: total fat mass (in kilograms), percentage of fat (in %), FMI (total fat mass/height2, in kg/m2), A/G ratio, and VAT (in g and cm3) Lean mass compartment: total lean mass (kg), ALM (kg), ALMI (adjusted by height [ALM/height2] and adjusted by BMI in patients over 65 years old [ALM/BMI]) | 98 |
5. What should be taken into account regarding quality control, accuracy, and least significant change (LSC)? | The quality control program should adhere to the manufacturer's guidelines for system maintenance. The quality control should include: Periodic (at least once a week) phantom scans for any DXA system as an independent assessment of system calibration Plotting and reviewing of data from calibration and phantom scans Establishment and enforcement of corrective action thresholds that trigger a call for service The precision error supplied by the manufacturer should not be used Each DXA device should have its own in vivo precision error determined and LSC calculated for all body composition variables | 99.7 |
6. What are the differences between normative data for the Brazilian compared with other populations? | Based on Brazilian normative database studies in adult men and women, the Brazilian population, compared with other populations, has some significant differences in body composition parameters, particularly regarding appendicular lean mass adjusted for height. Cutoff values of 7.77 kg/m2 and 5.62 kg/m2 (− 1 SD) are suggested for men and women. The combination of calf circumference (≤ 34 cm for males and ≤ 33 cm for females) and SARC-F into a modified index significantly improves the performance of SARC-F for screening sarcopenia | 98 |
7. What is the application of body composition assessment in pediatrics? | Numerous conditions may potentially interfere with body compartment distribution (lean, fat, and bone mass), including exogenous and endogenous overweight and obesity, environmental and disease-related undernutrition, anorexia, chronic drug therapy (e.g., corticosteroids, chemotherapy), and chronic diseases (e.g., systemic inflammatory disorders, inborn errors of metabolism, muscular dystrophies, and endocrine, gastrointestinal, heart, and pulmonary diseases). The most frequently used parameter for estimating body composition in routine practice in pediatrics is the BMI Interpretation of pediatric DXA data may be challenging due to physiological changes in body composition during growth, particularly in the absence of Brazilian normative reference data for children and adolescents. Thus, the adoption of the US normative database (NHANES III) is recommended for pediatric assessments in Brazil | 95.3 |
8. What is the clinical application of body composition assessment in patients infected with HIV? | Body composition assessment is recommended in patients infected with HIV for monitoring of body composition changes related to the disease and adverse effects associated with antiretroviral therapy, particularly abnormal body fat redistribution in the HIV-associated lipodystrophy spectrum The following parameters may be useful for assessing the presence of lipodystrophy in HIV-infected patients: limb-to-trunk fat ratio, trunk/leg fat ratio, and fat mass ratio | 97.3 |
9. How should body composition be assessed in transgender individuals? | Consistent data on body composition assessment in transgender individuals are currently unavailable. Until studies with more consistent data are published, we recommended the calculation of T-scores using a uniform Caucasian (non-race adjusted) female normative database for all transgender individuals of all ethnic groups and all transgender individuals aged 50 years or older, regardless of hormonal status. Z-scores should be calculated using the normative database that matches the gender identity of the individual (or based on both male and female databases, if requested by the physician). In gender-nonbinary individuals, the normative database that matches the sex recorded at birth should be used | 94.7 |
10. What is the role of DXA in veterinary medicine and zootechnics? | DXA can be used in veterinary medicine and animal sciences for measurement of whole-body composition in pigs, broilers, cats, dogs, and sheep, among others. Although normative data in these animals are scarce, this technique has a great potential in accurately evaluating the effectiveness of feeding interventions on the amount of lean and fat mass | 98 |