title: Urinary creatinine-skeletal muscle mass method: a prediction equation based on computerized axial tomography.
abstract: A classic body composition method is estimation of total body skeletal muscle mass (SM, kg) from 24 h urinary creatinine excretion (Cr, g). Two types of prediction equations were suggested: one assumes a constant SM/Cr ratio; and the other assumes a highly variable SM/Cr ratio. We explored these two extreme possibilities by measuring SM with whole-body computerized axial tomography and collecting Cr during meat-free dietary conditions in 12 healthy young men. Prediction equations were developed in the men that fit these two equation types, SM = 21.8 x Cr (SD and CV of SM/Cr ratio, 1.3 kg and 6.0%, respectively) and SM = 18.9 x Cr + 4.1 (r = 0.92, p = 2.55 x 10(-5), and SEE = 1.9 kg). The validity of each model is reviewed. This is the first investigation of Cr-SM method using modern techniques for quantifying total body SM mass.
authors.affiliation: Department of Medicine, St. Luke's-Roosevelt Hospital, Columbia University College of Physicians and Surgeons, New York, N.Y., USA.
authors.forename: Z M
authors.initials: ZM
authors.lastname: Wang
authors.forename: Y G
authors.initials: YG
authors.lastname: Sun
authors.forename: S B
authors.initials: SB
authors.lastname: Heymsfield
mesh_terms: D000328:Adult; D003404:Creatinine / Q000652:urine*; D005069:Evaluation Studies as Topic; D006801:Humans; D016014:Linear Models; D008297:Male; D008433:Mathematics; D018482:Muscle, Skeletal / Q000033:anatomy & histology* / Q000000981:diagnostic imaging; D012016:Reference Values; D014057:Tomography, X-Ray Computed
chemical_list: D003404:Creatinine