Measuring partial body potassium in the arm versus total body potassium

• Published in: Journal of applied physiology (1985) 2006-09, Vol.101 (3), p.945-949
• Main Authors: Wielopolski, L, Ramirez, L. M, Gallagher, D, Heymsfield, S. B, Wang, Z. M
• Format: Article
• Language: English
• Subjects: Adult; Algorithms; Arm - physiology; Arms; Biological and medical sciences; Feasibility Studies; Female; Fundamental and applied biological sciences. Psychology; Human body; Humans; Kidney - metabolism; Kinetics; Male; Muscle, Skeletal - metabolism; Musculoskeletal system; Organ Specificity; Potassium; Potassium - analysis; Potassium Radioisotopes - analysis; Radioisotope Dilution Technique; Reproducibility of Results; Sensitivity and Specificity; Spectrometry, Gamma - methods; Tissue Distribution; Whole-Body Counting - methods
• ISSN: 8750-7587; 1522-1601
• DOI: 10.1152/japplphysiol.00999.2005

1 Brookhaven National Laboratory, Medical Department, Upton, New York; and 2 St. Luke's/Roosevelt Hospital Center, Columbia University, Nutritional Medicine, New York, New York Submitted 18 August 2005 ; accepted in final form 8 May 2006 Skeletal muscle (SM), the body's main structural support, has been implicated in metabolic, physiological, and disease processes in humans. Despite being the largest tissue in the human body, its assessment remains difficult and indirect. However, being metabolically active it contains over 50% of the total body potassium (TBK) pool. We present our preliminary results from a new system for measuring partial body K (PBK) that presently are limited to the arm yet provide a direct and specific measure of the SM. This uniquely specific quantification of the SM mass in the arm, which is shielded from the body during measurement, allows us to simplify the assumptions used in deriving the total SM, thereby possibly improving the modeling of the human body compartments. Preliminary results show that PBK measurements are consistent with those from the TBK previously obtained from the same subjects, thus offering a simpler alternative to computed tomography and magnetic resonance imaging used for the same purposes. The PBK system, which can be set up in a physician's office or bedside in a hospital, is completely passive, safe, and inexpensive; it can be used on immobilized patients, children, pregnant women, or other at-risk populations. body composition; in vivo; gamma ray spectroscopy Address for reprint requests and other correspondence: L. Wielopolski, Brookhaven National Laboratory, Bldg. 490D, Upton, NY 11973 (e-mail: lwielo{at}bnl.gov )