title: Assessment of Protein Turnover in Health and Disease.
abstract: To identify protein requirements, it is necessary to be familiar with basic physiology, practical methods, and dose response of protein delivery. This review evaluates available methodology, with emphasis on the limitations of existing techniques most often related to the underlying assumption. Historically, nitrogen balance has been the dominating technique. It is still the gold standard, although there are considerable problems related to the underlying assumptions to have reliable readings. When minimal requirements needed to be defined, the indicator amino acid oxidation technique came into practice. In situations of longer term steady states, it serves a purpose. In situations of disease or in aging, it has proven to be more problematic. More recently, whole-body protein turnover measurements have shown to be useful in situations where the underlying assumptions for the other techniques are not possible to meet.
authors.affiliation: 1 Karolinska University Hospital Huddinge and Karolinska Institutet, Stockholm, Sweden.
authors.forename: Jan
authors.initials: J
authors.lastname: Wernerman
authors.affiliation: 2 Emory University School of Medicine, Atlanta, Georgia, USA.
authors.forename: Claudia R
authors.initials: CR
authors.lastname: Morris
authors.affiliation: 3 Department of Nutrition and Metabolism, The University of Texas Medical Branch, Galveston, Texas, USA.
authors.forename: Douglas
authors.initials: D
authors.lastname: Paddon-Jones
authors.affiliation: 4 Section of Nephrology and Hypertension, NorthShore University HealthSystem, University of Chicago, Evanston, Illinois, USA.
authors.forename: Menaka
authors.initials: M
authors.lastname: Sarav
mesh_terms: D000368:Aged; D000375:Aging; D004044:Dietary Proteins / Q000378:metabolism*; D006801:Humans; D008875:Middle Aged; D015596:Nutrition Assessment; D009751:Nutritional Requirements; D010084:Oxidation-Reduction
chemical_list: D004044:Dietary Proteins
keywords: amino acids; critical illness; nitrogen balance; protein