Total body skeletal muscle mass: estimation by creatine (methyl-d3) dilution in humans.

Clark, Richard V

Walker, Ann C

O'Connor-Semmes, Robin L

Leonard, Michael S

Miller, Ram R

Stimpson, Stephen A

Turner, Scott M

Ravussin, Eric

Cefalu, William T

Hellerstein, Marc K

Evans, William J

United States

2017-01-01T19:11:05Z

2017-01-01T19:11:05Z

2014-06-15

Current methods for clinical estimation of total body skeletal muscle mass have significant limitations. We tested the hypothesis that creatine (methyl-d3) dilution (D3-creatine) measured by enrichment of urine D3-creatinine reveals total body creatine pool size, providing an accurate estimate of total body skeletal muscle mass. Healthy subjects with different muscle masses [n = 35: 20 men (19-30 yr, 70-84 yr), 15 postmenopausal women (51-62 yr, 70-84 yr)] were housed for 5 days. Optimal tracer dose was explored with single oral doses of 30, 60, or 100 mg D3-creatine given on day 1. Serial plasma samples were collected for D3-creatine pharmacokinetics. All urine was collected through day 5. Creatine and creatinine (deuterated and unlabeled) were measured by liquid chromatography mass spectrometry. Total body creatine pool size and muscle mass were calculated from D3-creatinine enrichment in urine. Muscle mass was also measured by magnetic resonance imaging (MRI), dual-energy x-ray absorptiometry (DXA), and traditional 24-h urine creatinine. D3-creatine was rapidly absorbed and cleared with variable urinary excretion. Isotopic steady-state of D3-creatinine enrichment in the urine was achieved by 30.7 ± 11.2 h. Mean steady-state enrichment in urine provided muscle mass estimates that correlated well with MRI estimates for all subjects (r = 0.868, P < 0.0001), with less bias compared with lean body mass assessment by DXA, which overestimated muscle mass compared with MRI. The dilution of an oral D3-creatine dose determined by urine D3-creatinine enrichment provides an estimate of total body muscle mass strongly correlated with estimates from serial MRI with less bias than total lean body mass assessment by DXA.

http://www.ncbi.nlm.nih.gov/pubmed/24764133

japplphysiol.00045.2014

1522-1601

https://hdl.handle.net/10161/13299

eng

American Physiological Society

J Appl Physiol (1985)

10.1152/japplphysiol.00045.2014

creatine

creatinine

lean body mass

muscle mass

Adult

Aged

Aged, 80 and over

Body Composition

Chromatography, Liquid

Creatine

Creatinine

Female

Humans

Indicator Dilution Techniques

Male

Mass Spectrometry

Middle Aged

Muscle, Skeletal

Total body skeletal muscle mass: estimation by creatine (methyl-d3) dilution in humans.

Journal article

http://www.ncbi.nlm.nih.gov/pubmed/24764133

1605

1613

12

Clinical Science Departments

Duke

Medicine

Medicine, Geriatrics

School of Medicine

Published

116