title: Individual variation in macronutrient regulation measured by proton magnetic resonance spectroscopy of human plasma.
abstract: Proton nuclear magnetic resonance ((1)H-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 (1)H 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 (-CH(2)- and -CH(2)OCOR), and the region between 3 and 4 ppm heavily overlapped with amino acids that had alpha-CH and alpha-CH(2). 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 (1)H-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, (1)H-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.
authors.affiliation: Department of Medicine, Emory University, Atlanta, Georgia 30322, USA.
authors.forename: Youngja
authors.initials: Y
authors.lastname: Park
authors.forename: Seoung Bum
authors.initials: SB
authors.lastname: Kim
authors.forename: Bing
authors.initials: B
authors.lastname: Wang
authors.forename: Roberto A
authors.initials: RA
authors.lastname: Blanco
authors.forename: Ngoc-Anh
authors.initials: NA
authors.lastname: Le
authors.forename: Shaoxiong
authors.initials: S
authors.lastname: Wu
authors.forename: Carolyn J
authors.initials: CJ
authors.lastname: Accardi
authors.forename: R Wayne
authors.initials: RW
authors.lastname: Alexander
authors.forename: Thomas R
authors.initials: TR
authors.lastname: Ziegler
authors.forename: Dean P
authors.initials: DP
authors.lastname: Jones
mesh_terms: D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D000596:Amino Acids / Q000097:blood; D002940:Circadian Rhythm; D016000:Cluster Analysis; D004040:Dietary Carbohydrates / Q000097:blood*; D004041:Dietary Fats / Q000097:blood*; D004044:Dietary Proteins / Q000097:blood*; D004435:Eating; D004734:Energy Metabolism; D005215:Fasting / Q000097:blood; D005260:Female; D006706:Homeostasis; D006801:Humans; D009682:Magnetic Resonance Spectroscopy; D008297:Male; D055432:Metabolomics / Q000379:methods*; D008875:Middle Aged; D019518:Postprandial Period; D025341:Principal Component Analysis; D012016:Reference Values; D055815:Young Adult
chemical_list: D000596:Amino Acids; D004040:Dietary Carbohydrates; D004041:Dietary Fats; D004044:Dietary Proteins