title: Derivation and validation of simple anthropometric equations to predict adipose tissue mass and total fat mass with MRI as the reference method.
abstract: The reference organ-level body composition measurement method is MRI. Practical estimations of total adipose tissue mass (TATM), total adipose tissue fat mass (TATFM) and total body fat are valuable for epidemiology, but validated prediction equations based on MRI are not currently available. We aimed to derive and validate new anthropometric equations to estimate MRI-measured TATM/TATFM/total body fat and compare them with existing prediction equations using older methods. The derivation sample included 416 participants (222 women), aged between 18 and 88 years with BMI between 15·9 and 40·8 (kg/m2). The validation sample included 204 participants (110 women), aged between 18 and 86 years with BMI between 15·7 and 36·4 (kg/m2). Both samples included mixed ethnic/racial groups. All the participants underwent whole-body MRI to quantify TATM (dependent variable) and anthropometry (independent variables). Prediction equations developed using stepwise multiple regression were further investigated for agreement and bias before validation in separate data sets. Simplest equations with optimal R (2) and Bland-Altman plots demonstrated good agreement without bias in the validation analyses: men: TATM (kg)=0·198 weight (kg)+0·478 waist (cm)-0·147 height (cm)-12·8 (validation: R 2 0·79, CV=20 %, standard error of the estimate (SEE)=3·8 kg) and women: TATM (kg)=0·789 weight (kg)+0·0786 age (years)-0·342 height (cm)+24·5 (validation: R (2) 0·84, CV=13 %, SEE=3·0 kg). Published anthropometric prediction equations, based on MRI and computed tomographic scans, correlated strongly with MRI-measured TATM: (R (2) 0·70-0·82). Estimated TATFM correlated well with published prediction equations for total body fat based on underwater weighing (R (2) 0·70-0·80), with mean bias of 2·5-4·9 kg, correctable with log-transformation in most equations. In conclusion, new equations, using simple anthropometric measurements, estimated MRI-measured TATM with correlations and agreements suitable for use in groups and populations across a wide range of fatness.
authors.affiliation: 1Department of Human Nutrition,School of Medicine,College of Medical,Veterinary & Life Sciences,University of Glasgow,Royal Infirmary,Glasgow G4 0SF,UK.
authors.forename: Yasmin Y
authors.initials: YY
authors.lastname: Al-Gindan
authors.affiliation: 1Department of Human Nutrition,School of Medicine,College of Medical,Veterinary & Life Sciences,University of Glasgow,Royal Infirmary,Glasgow G4 0SF,UK.
authors.forename: Catherine R
authors.initials: CR
authors.lastname: Hankey
authors.affiliation: 2Department of Human Nutrition,Institute of Health and Well Being,College of Medical,Veterinary & Life Sciences,University of Glasgow,Glasgow G12 8QQ,UK.
authors.forename: Lindsay
authors.initials: L
authors.lastname: Govan
authors.affiliation: 3Institute of Human Nutrition,Columbia University,New York, NY,USA.
authors.forename: Dympna
authors.initials: D
authors.lastname: Gallagher
authors.affiliation: 4Department of Metabolism-Body Composition,Pennington Biomedical Research Center,Baton Rouge,LA 70808,USA.
authors.forename: Steven B
authors.initials: SB
authors.lastname: Heymsfield
authors.affiliation: 1Department of Human Nutrition,School of Medicine,College of Medical,Veterinary & Life Sciences,University of Glasgow,Royal Infirmary,Glasgow G4 0SF,UK.
authors.forename: Michael E J
authors.initials: ME
authors.lastname: Lean
mesh_terms: D000273:Adipose Tissue / Q000473:pathology*; D050154:Adiposity; D000293:Adolescent; D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D000465:Algorithms; D015992:Body Mass Index; D005260:Female; D006801:Humans; D008279:Magnetic Resonance Imaging; D008297:Male; D008875:Middle Aged; D008954:Models, Biological; D009765:Obesity / Q000175:diagnosis* / Q000473:pathology; D009767:Obesity, Morbid / Q000175:diagnosis* / Q000473:pathology; D050177:Overweight / Q000175:diagnosis* / Q000473:pathology; D011237:Predictive Value of Tests; D012727:Sex Characteristics; D013851:Thinness / Q000175:diagnosis* / Q000473:pathology; D051598:Whole Body Imaging; D055815:Young Adult
keywords: Adipose tissue; Anthropometry; CT computed tomography; Epidemiology; MRI; PI prediction interval; Prediction equations; SEE standard error of the estimate; TATFM total adipose tissue fat mass; TATM total adipose tissue mass; Total body fat; UWW underwater weighing