Maya G Panisset1, Kate Desneves2, Leigh C Ward3, Jillian Rafferty2, Helena Rodi2, Geoff Roff4, Doa El-Ansary5, Mary P Galea6,7. 1. Department of Medicine, Royal Melbourne Hospital, The University of Melbourne, Parkville, VIC, Australia. 2. Department of Dietetics and Nutrition, Austin Health, Heidelberg, VIC, Australia. 3. School of Chemistry and Molecular Biosciences, The University of Queensland, St Lucia, QLD, Australia. 4. Bone and Mineral Research Unit, Austin Health, Heidelberg, VIC, Australia. 5. Department of Physiotherapy, The University of Melbourne, Parkville, VIC, Australia. 6. Department of Medicine, Royal Melbourne Hospital, The University of Melbourne, Parkville, VIC, Australia. m.galea@unimelb.edu.au. 7. School of Chemistry and Molecular Biosciences, The University of Queensland, St Lucia, QLD, Australia. m.galea@unimelb.edu.au.
Abstract
STUDY DESIGN: Psychometric. OBJECTIVES: Assess the validity of bioimpedance-based measures of fat-free mass (FFM) in acute SCI and of current definitions of obesity based on body mass index (BMI). SETTING: Australia. METHODS: All admissions within eight weeks of a new traumatic SCI were screened. 29% were eligible. 71% of those consented. Twenty participants (18 male) completed deuterium dilution (DD) and bioimpedance-based measurements of FFM. Thirteen also underwent dual-energy x-ray absorptiometry. Strength of relationships and agreement were examined using Lin's concordance coefficient and limits of agreement analysis, respectively. Sensitivity and specificity were calculated for three BMI cutoffs for obesity, using percentage fat mass (%FM) obtained from DD as reference. RESULTS: Median time since injury was 41 days (IQR 28-48). FFM from DD and DXA were highly correlated but not identical. Concordance and agreement between DD and seven bioimpedance-based predictive equations are presented. The best-fitting equation demonstrated a low bias (+0.6 kg) and moderate dispersion (±5.2 kg). The cutoff for overweight in able-bodied people (BMI ≥25 kg/m2) provided sensitivity of 43.8%, compared to 25% for the cut-off for obesity (BMI ≥30 kg/m2). FM from bioimpedance gave the highest sensitivity (88.9%). CONCLUSIONS: BMI demonstrates poor specificity to classify obesity in acute SCI. Present findings support the utility of bioimpedance-based measurements for estimating FFM in acute SCI for group comparisons. These results are generalizable to traumatic SCI 4-8 weeks post injury; however, the present data reflect a high proportion of high cervical injuries. Further research is indicated to establish validity for assessment of individuals and for longitudinal monitoring. SPONSORSHIP: The present study was funded by a grant from the Institute for Safety, Compensation and Recovery Research (ISCRR Project #NGE-E-13-078). M Panisset was supported by an Australian Postgraduate Award. K Desneves was supported by the Austin Medical Research Foundation.
STUDY DESIGN: Psychometric. OBJECTIVES: Assess the validity of bioimpedance-based measures of fat-free mass (FFM) in acute SCI and of current definitions of obesity based on body mass index (BMI). SETTING: Australia. METHODS: All admissions within eight weeks of a new traumatic SCI were screened. 29% were eligible. 71% of those consented. Twenty participants (18 male) completed deuterium dilution (DD) and bioimpedance-based measurements of FFM. Thirteen also underwent dual-energy x-ray absorptiometry. Strength of relationships and agreement were examined using Lin's concordance coefficient and limits of agreement analysis, respectively. Sensitivity and specificity were calculated for three BMI cutoffs for obesity, using percentage fat mass (%FM) obtained from DD as reference. RESULTS: Median time since injury was 41 days (IQR 28-48). FFM from DD and DXA were highly correlated but not identical. Concordance and agreement between DD and seven bioimpedance-based predictive equations are presented. The best-fitting equation demonstrated a low bias (+0.6 kg) and moderate dispersion (±5.2 kg). The cutoff for overweight in able-bodied people (BMI ≥25 kg/m2) provided sensitivity of 43.8%, compared to 25% for the cut-off for obesity (BMI ≥30 kg/m2). FM from bioimpedance gave the highest sensitivity (88.9%). CONCLUSIONS: BMI demonstrates poor specificity to classify obesity in acute SCI. Present findings support the utility of bioimpedance-based measurements for estimating FFM in acute SCI for group comparisons. These results are generalizable to traumatic SCI 4-8 weeks post injury; however, the present data reflect a high proportion of high cervical injuries. Further research is indicated to establish validity for assessment of individuals and for longitudinal monitoring. SPONSORSHIP: The present study was funded by a grant from the Institute for Safety, Compensation and Recovery Research (ISCRR Project #NGE-E-13-078). M Panisset was supported by an Australian Postgraduate Award. K Desneves was supported by the Austin Medical Research Foundation.
Authors: Fernando Seoane; Shirin Abtahi; Farhad Abtahi; Lars Ellegård; Gudmundur Johannsson; Ingvar Bosaeus; Leigh C Ward Journal: Biomed Res Int Date: 2015-06-02 Impact factor: 3.411
Authors: Jan W van der Scheer; Julia O Totosy de Zepetnek; Cheri Blauwet; Katherine Brooke-Wavell; Terri Graham-Paulson; Amber N Leonard; Nick Webborn; Victoria L Goosey-Tolfrey Journal: PLoS One Date: 2021-05-07 Impact factor: 3.240