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This Article Full Text Full Text (PDF) Supplemental Data All Versions of this Article: 297/1/R202    most recent 90757.2008v1 Alert me when this article is cited Alert me if a correction is posted Citation Map Services Email this article to a friend Similar articles in this journal Similar articles in PubMed Alert me to new issues of the journal Download to citation manager Google Scholar Articles by Park, Y. Articles by Jones, D. P. PubMed PubMed Citation Articles by Park, Y. Articles by Jones, D. P.

ARTICLES

Individual variation in macronutrient regulation measured by proton magnetic resonance spectroscopy of human plasma

Departments of ¹Medicine and ³Chemistry, Emory University, Atlanta, Georgia; and ²Department of Industrial Systems and Information Engineering, Korea University, Seoul, South Korea

Submitted 9 September 2008 ; accepted in final form 13 May 2009

Proton nuclear magnetic resonance (¹H-NMR) spectroscopy of plasma provides a global metabolic profiling method that shows promise for clinical diagnostics. However, cross-sectional studies are complicated by a lack of understanding of intraindividual variation, and this limits experimental design and interpretation of data. The present study determined the diurnal variation detected by ¹H NMR spectroscopy of human plasma. Data reduction methods revealed three time-of-day metabolic patterns, which were associated with morning, afternoon, and night. Major discriminatory regions for these time-of-day patterns included the various kinds of lipid signals (-CH₂- and -CH₂OCOR), and the region between 3 and 4 ppm heavily overlapped with amino acids that had -CH and -CH₂. The phasing and duration of time-of-day patterns were variable among individuals, apparently because of individual difference in food processing/digestion and absorption and clearance of macronutrient energy sources (fat, protein, carbohydrate). The times of day that were most consistent among individuals, and therefore most useful for cross-sectional studies, were fasting morning (0830–0930), postprandial afternoon (1430–1630), and nighttime samples (0430–0530). Importantly, the integrated picture of metabolism provided by ¹H-NMR spectroscopy of plasma suggests that this approach is suitable to study complex regulatory processes, including eating patterns/eating disorders, upper gastrointestinal functions (gastric emptying, pancreatic, biliary functions), and absorption/clearance of macronutrients. Hence, ¹H-NMR spectroscopy of plasma could provide a global metabolic tolerance test to assess complex processes involved in disease, including eating disorders and the range of physiological processes causing dysregulation of energy homeostasis.

metabolomics; diurnal variation; eating disorders; gastrointestinal regulation