title: Multifractal analysis for nutritional assessment.
abstract: The concept of multifractality is currently used to describe self-similar and complex scaling properties observed in numerous biological signals. Fractals are geometric objects or dynamic variations which exhibit some degree of similarity (irregularity) to the original object in a wide range of scales. This approach determines irregularity of biologic signal as an indicator of adaptability, the capability to respond to unpredictable stress, and health. In the present work, we propose the application of multifractal analysis of wavelet-transformed proton nuclear magnetic resonance ((1)H NMR) spectra of plasma to determine nutritional insufficiency. For validation of this method on (1)H NMR signal of human plasma, standard deviation from classical statistical approach and Hurst exponent (H), left slope and partition function from multifractal analysis were extracted from (1)H NMR spectra to test whether multifractal indices could discriminate healthy subjects from unhealthy, intensive care unit patients. After validation, the multifractal approach was applied to spectra of plasma from a modified crossover study of sulfur amino acid insufficiency and tested for associations with blood lipids. The results showed that standard deviation and H, but not left slope, were significantly different for sulfur amino acid sufficiency and insufficiency. Quadratic discriminant analysis of H, left slope and the partition function showed 78% overall classification accuracy according to sulfur amino acid status. Triglycerides and apolipoprotein C3 were significantly correlated with a multifractal model containing H, left slope, and standard deviation, and cholesterol and high-sensitivity C-reactive protein were significantly correlated to H. In conclusion, multifractal analysis of (1)H NMR spectra provides a new approach to characterize nutritional status.
authors.affiliation: Division of Pulmonary, Allergy and Critical Care Medicine, Department of Medicine, Emory University, Atlanta, Georgia, United States of America ; College of Pharmacy, Korea University, Sejong City, Korea.
authors.forename: Youngja
authors.initials: Y
authors.lastname: Park
authors.forename: Kichun
authors.initials: K
authors.lastname: Lee
authors.forename: Thomas R
authors.initials: TR
authors.lastname: Ziegler
authors.forename: Greg S
authors.initials: GS
authors.lastname: Martin
authors.forename: Gautam
authors.initials: G
authors.lastname: Hebbar
authors.forename: Brani
authors.initials: B
authors.lastname: Vidakovic
authors.forename: Dean P
authors.initials: DP
authors.lastname: Jones
mesh_terms: D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D000596:Amino Acids / Q000737:chemistry; D001056:Apolipoproteins C / Q000737:chemistry; D001331:Automation; D015992:Body Mass Index; D002940:Circadian Rhythm; D003422:Critical Care; D016638:Critical Illness; D018592:Cross-Over Studies; D005260:Female; D017709:Fractals; D006801:Humans; D008055:Lipids / Q000097:blood; D009682:Magnetic Resonance Spectroscopy; D008297:Male; D008875:Middle Aged; D015596:Nutrition Assessment; D010949:Plasma / Q000737:chemistry*; D012815:Signal Processing, Computer-Assisted; D013455:Sulfur / Q000737:chemistry; D014280:Triglycerides / Q000737:chemistry; D055815:Young Adult
chemical_list: D000596:Amino Acids; D001056:Apolipoproteins C; D008055:Lipids; D014280:Triglycerides; D013455:Sulfur