title: Differentiation of Overweight from Normal Weight Young Adults by Postprandial Heart Rate Variability and Systolic Blood Pressure.
abstract: BACKGROUND
  Obesity and cardiovascular disease are inextricably linked and the health community's response to the current epidemic of adolescent obesity may be improved by the ability to target adolescents at highest risk for developing cardiovascular disease in the future. Overweight manifests early as autonomic dysregulation and current methods do not permit differentiation of overweight adolescents or young adults at highest risk for developing cardiovascular disease.
  
  
  OBJECTIVE
  This study was designed to test the hypothesis that scaling exponents motivated by nonlinear fractal analyses of Heart Rate Variability (HRV) differentiate overweight, otherwise healthy adolescent/young adult subjects at risk for developing prehypertension, the primary forerunner of cardiovascular disease.
  
  
  METHODS
  The subjects were 18-20year old males with Body Mass Index (BMI) 20.1-42.5kg/m(2). Electrocardiographic inter-beat (RR) intervals were measured during 3h periods of bed rest after overnight fasting and ingestion of 900Cal high-carbohydrate and high-fat test beverages on separate days. Detrended Fluctuation Analysis (DFA), k-means cluster and ANOVA analyses of scaling coefficients α, α(1), and α(2), showed dependencies on hourly measurements of systolic blood pressure and on premeasured BMI.
  
  
  RESULTS
  It was observed that α value increased during the caloric challenge, appears to represent metabolically-induced changes in HRV across the participants. An ancillary analysis was performed to determine the dependency on BMI without BMI as a parameter. Cluster analysis of the high-carbohydrate test beverage treatment and the high-fat treatment produced grouping with very little overlap. ANOVA on both clusters demonstrated significance at p<0.001. We were able to demonstrate increased sympathetic modulation of our study group during ingestion and metabolism of isocaloric high-carbohydrate and high-fat test beverages.
  
  
  CONCLUSIONS
  These findings demonstrate significantly different clustering of α, α1, and α2 and Systolic Blood Pressure (SBP) with respect to normal, overweight and obese BMI.
authors.affiliation: Student, Department of Physics & Astronomy, Howard University , Washington, DC 20059, United States of America .
authors.forename: Lauren
authors.initials: L
authors.lastname: Taffe
authors.affiliation: Professor, Department of Mathematics and Science, U.S. Merchant Marine Academy , Kingspoint, New York, United States of America .
authors.forename: Kimani
authors.initials: K
authors.lastname: Stancil
authors.affiliation: Professor, Department of Recreation, Human Performance & Leisure Studies and Exercise Science & Human Nutrition Laboratory, Howard University Cancer Centre , Washington, DC 20060, United States of America .
authors.forename: Vernon
authors.initials: V
authors.lastname: Bond
authors.affiliation: Associate Professor, Department of Medical Pharmacology, AUA College of Medicine & Manipal University , Antigua & India .
authors.forename: Sudhakar
authors.initials: S
authors.lastname: Pemminati
authors.affiliation: Assistant Professor, Department of Behavioural Sciences and Neuroscience, AUA College of Medicine , Antigua .
authors.forename: Vasavi Rakesh
authors.initials: VR
authors.lastname: Gorantla
authors.affiliation: Assistant Professor, Department of Medical Physiology, AUA College of Medicine , Antigua .
authors.forename: Kishan
authors.initials: K
authors.lastname: Kadur
authors.affiliation: Professor, Department of Medical Physiology, AUA College of Medicine , Antigua .
authors.forename: Richard Mark
authors.initials: RM
authors.lastname: Millis
keywords: Body mass index; Detrended fluctuation analysis; Energy substrate metabolism; K-means cluster analysis; Obesity