title: Assessment of body composition by dual-energy X-ray absorptiometry, bioimpedance analysis and anthropometrics in children: the Physical Activity and Nutrition in Children study.
abstract: OBJECTIVE
  We compared InBody720 segmental multifrequency bioimpedance analysis (SMF-BIA) with Lunar Prodigy Advance dual-energy X-ray absorptiometry (DXA) in assessment of body composition among 178 predominantly prepubertal children. Segmental agreement analysis of body compartments was carried out, and inter-relationships of anthropometric and other measures of body composition were defined. Moreover, the relations of different reference criteria for excess body fat were evaluated.
  
  
  RESULTS
  The prevalence of excess body fat varies greatly according to the used criteria. Intraclass and Pearson's correlations between SMF-BIA and DXA were >0·92 in total body and >0·74 in regional measures. SMF-BIA underestimated percentage body fat (%BF) and fat mass (FM), and overestimated lean mass (LM) and percentage LM with significant offset trend bias. Higher adiposity increased offsets, and overall agreement was poorer in girls. On average, %BF offsets (girls/boys) and limits of agreement (LA) were 3·9/1·6% [(-)1·4-9·2%/(-)3·4-6·7%]. Interestingly percentage offsets of fat content (%BF: 18·9/10·1%, FM: 18·8/11·1%) showed no significant bias trends indicating that the corresponding absolute methodological offset depends on the amount of fat content. The smallest percentage offset was found with LM: 4·3/0·1%, referring offset (LA) of 0·88/0·03 kg (±2·05/±1·71 kg). Correspondingly, segmental LM had poorer agreement than total body LM. All anthropometrics except for the waist-to-hip ratio showed strong correlations (r = 0·76-0·95) with abdominal and total body fat.
  
  
  CONCLUSIONS
  Segmental multifrequency bioimpedance analysis is precise enough for total-LM analysis and had also sufficient trueness for total body composition analysis to be used in epidemiological purposes. There is need to generate scientifically and clinically relevant criteria and reference values for excess body fat.
authors: Department of Clinical Physiology and Nuclear Medicine, Kuopio University Hospital, University of Eastern Finland, Kuopio, Finland.|Department of Physiology, Institute of Biomedicine, University of Eastern Finland, Kuopio, Finland.
authors: Tuomo T
authors: TT
authors: Tompuri
authors: Department of Clinical Physiology and Nuclear Medicine, Kuopio University Hospital, University of Eastern Finland, Kuopio, Finland.|Department of Physiology, Institute of Biomedicine, University of Eastern Finland, Kuopio, Finland.|Kuopio Research Institute of Exercise Medicine, Kuopio, Finland.
authors: Timo A
authors: TA
authors: Lakka
authors: Department of Clinical Physiology and Nuclear Medicine, Kuopio University Hospital, University of Eastern Finland, Kuopio, Finland.
authors: Mikko
authors: M
authors: Hakulinen
authors: Department of Physiology, Institute of Biomedicine, University of Eastern Finland, Kuopio, Finland.
authors: Virpi
authors: V
authors: Lindi
authors: Department of Internal Medicine, Kuopio University Hospital, Kuopio, Finland.
authors: David E
authors: DE
authors: Laaksonen
authors: Department of Physiology, Institute of Biomedicine, University of Eastern Finland, Kuopio, Finland.|The Novo Nordisk Foundation Center for Basic Metabolic Research, Section of Metabolic Genetics, Faculty of Health and Medical Sciences, University of Copenhagen, Copenhagen, Denmark.
authors: Tuomas O
authors: TO
authors: Kilpeläinen
authors: Department of Pediatrics, Kuopio University Hospital, University of Eastern Finland, Kuopio, Finland.
authors: Jarmo
authors: J
authors: Jääskeläinen
authors: Department of Physiology, Institute of Biomedicine, University of Eastern Finland, Kuopio, Finland.|Finnish Medicines Agency, Helsinki, Finland.
authors: Hanna-Maaria
authors: HM
authors: Lakka
authors: Department of Clinical Physiology and Nuclear Medicine, Kuopio University Hospital, University of Eastern Finland, Kuopio, Finland.
authors: Tomi
authors: T
authors: Laitinen
mesh_terms: D015502:Absorptiometry, Photon / Q000379:methods*; D050154:Adiposity / Q000502:physiology*; D000886:Anthropometry / Q000379:methods*; D001823:Body Composition / Q000502:physiology*; D002648:Child; D003198:Computer Simulation; D005260:Female; D006801:Humans; D008297:Male; D008954:Models, Biological; D010992:Plethysmography, Impedance / Q000379:methods*; D015203:Reproducibility of Results; D012680:Sensitivity and Specificity; D012727:Sex Characteristics
keywords: adiposity; bioimpedance analysis; dual-energy X-ray absorptiometry; obesity; overweight; paediatric; validation