title: Bioelectrical impedance analysis can be a useful screen for excess adiposity in spinal muscular atrophy.
abstract: Accurate, noninvasive measures of body composition are needed for management of patients with spinal muscular atrophy. Fat mass index (fat mass/height(2) in kg/m(2)) was measured in 16 subjects with spinal muscular atrophy using 5 bioelectrical impedance analysis equations and compared with a reference method, dual-energy x-ray absorptiometry. The machine default equation, validated by Cordain, was the primary analysis. Fat mass index calculated by impedance measures differed by between -2.5 kg/m(2) and 1.7 kg/m(2) from the reference mean (8.3 ± 5.0 kg/m(2)). The Cordain equation provided the smallest difference (-0.4 ± 2.0 kg/m(2)), with correlation coefficient of 0.92. The Cordain equation showed high sensitivity (85.7%) and specificity (100%) for prediction of ''at risk for overweight'' (fat mass index > 85th percentile for age and gender). Although insufficiently accurate for use as a research tool, bioelectrical impedance can have application as a well-tolerated, noninvasive, easily used screening tool for excess adiposity in patients with spinal muscular atrophy.
authors.affiliation: Division of Pediatric Neurosciences, Department of Neurology, SMA Clinical Research Center, Columbia University Medical Center, New York, New York 10032-3791, USA. dsproule@neuro.columbia.edu
authors.forename: Douglas M
authors.initials: DM
authors.lastname: Sproule
authors.forename: Jacqueline
authors.initials: J
authors.lastname: Montes
authors.forename: Sally L
authors.initials: SL
authors.lastname: Dunaway
authors.forename: Megan
authors.initials: M
authors.lastname: Montgomery
authors.forename: Vanessa
authors.initials: V
authors.lastname: Battista
authors.forename: Wei
authors.initials: W
authors.lastname: Shen
authors.forename: Mark
authors.initials: M
authors.lastname: Punyanitya
authors.forename: Darryl C
authors.initials: DC
authors.lastname: De Vivo
authors.forename: Petra
authors.initials: P
authors.lastname: Kaufmann
mesh_terms: D015502:Absorptiometry, Photon; D050154:Adiposity; D000293:Adolescent; D000328:Adult; D002648:Child; D002675:Child, Preschool; D017097:Electric Impedance; D005260:Female; D006801:Humans; D008297:Male; D008875:Middle Aged; D009134:Muscular Atrophy, Spinal / Q000150:complications*; D050177:Overweight / Q000150:complications / Q000175:diagnosis*; D012680:Sensitivity and Specificity