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Research Abstracts Online
January 2010 - March 2011

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University of Minnesota Twin Cities
Medical School
Department of Integrative Biology and Physiology

PI: Germaine G. Cornélissen-Guillaume

Assessment of Physiologic Chronomes From Womb to Tomb

Chronobiologic analyses assess abnormal circadian patterns of variability in blood pressure (BP) and heart rate (HR) that in addition to high BP elevate cardiovascular disease risk. Reduced HR variability, excessive circadian BP amplitude (CHAT), an odd timing of the circadian variation in BP, and an excessive pulse pressure are largely independent risk factors, contributing additively to the risk of adverse vascular events. Vascular disease risk is increased when several such abnormalities coexist. Ecfrequentia is a new vascular variability disorder characterized by a circadian period deviating from 24.0 hours, found in a 61-year old woman in association with repeated episodes of adynamia (loss of vigor). Focus is placed upon disease prevention, adjusting the kind and scheduling of treatment to the chronodiagnosis, a procedure leading to the concept of chronotheranostics. The same dose of the same drug administered to the same patient has been shown to either induce or eliminate CHAT when administered at one or another circadian stage (six test times, three hours apart from awakening to bedtime, each tested for at least one month). Beyond serving to improve screening, diagnosis and treatment, worldwide monitoring and analyses of BP and HR records also serve basic science, notably to assess how environmental factors affect human physiology. The concept of congruence (overlapping of periods’ confidence intervals) gauges in inferential statistical terms influences of space weather on physiology and pathology. These researchers’ pursuit of these goals is greatly facilitated by access to the supercomputers to: analyze long and dense data series; organize data into databases; automatically update reference standards as added data accumulate; detect the earliest risk by means of chronome alterations; follow up at-risk individuals longitudinally by means of control charts; and explore large parameter spaces in nonlinear analyses not requiring the specification of initial values.

Group Members

Franz Halberg, Associate Fellow, Co-Principal Investigator
Jerzy Czaplicki, Institute of Pharmacology and Structural Biology, Paul Sabatier University, Toulouse, France
Dewayne Hillman, Halberg Chronobiology Center, University of Minnesota, Minneapolis, Minnesota
Miguel A. Revilla, Department of Applied and Computational Mathematics, Faculty of Sciences, University of Valladolid, Valladolid, Spain