alexa Factors affecting the 2H to 18O dilution space ratio in infants.
Diabetes & Endocrinology

Diabetes & Endocrinology

Journal of Obesity & Weight Loss Therapy

Author(s): Wells JC, Ritz P, Davies PS, Coward WA

Abstract Share this page

Abstract In the doubly labeled water (DLW) method, for measurement of energy expenditure in humans, calculation of carbon dioxide production rate is influenced by the ratio (R) of the dilution spaces of the tracer isotopes 2H and 18O. Recent publications have recommended use of a fixed value for R, using a mean population value (meanR) rather than individually derived experimental values. However, most of the data considered previously were derived from adults. Infants are characterized by rapid rates of energy deposition and high body water content, either of which could influence isotope kinetics. We have considered whether use of a fixed R value is suitable for DLW studies of infants, and whether the adult (meanR) value is appropriate. Data from 281 DLW measurements in healthy infants aged 6 wk to 12 mo were analyzed. Mean R of all measurements was 1.036 (SD 0.019), very similar to (meanR) values recommended for adults. We found analytical precision could account for almost all between-subject variation at a single time point. However, we also found relationships between R and age and weight gain, indicating that physiology does influence the space ratio. The effect of weight gain on R was negligible, but changes of (meanR) with age, reflecting changes in percentage body water during infancy, were of sufficient magnitude to affect calculation of energy expenditure significantly. Our analysis suggests that use of a fixed ratio at a single time point in infancy is acceptable, but that the appropriate value of (meanR) changes over the first year of life. This article was published in Pediatr Res and referenced in Journal of Obesity & Weight Loss Therapy

Relevant Expert PPTs

Relevant Speaker PPTs

Recommended Conferences

  • 13th World Congress on Obesity
    Aug 24-25, 2017, Toronto, Canada
  • 13th Euro Obesity and Endocrinology Congress
    Sep 21-23, 2017, Madrid, Spain
  • 14th Global Obesity Meeting
    Oct 23-24, 2017 Dubai, UAE
  • 16th International Conference and Exhibition on Obesity & Weight Management
    November 13-15, 2017 Atlanta,Georgia, USA

Relevant Topics

Peer Reviewed Journals
Make the best use of Scientific Research and information from our 700 + peer reviewed, Open Access Journals
International Conferences 2017-18
Meet Inspiring Speakers and Experts at our 3000+ Global Annual Meetings

Contact Us

© 2008-2017 OMICS International - Open Access Publisher. Best viewed in Mozilla Firefox | Google Chrome | Above IE 7.0 version