Over the past 2 decades of collaborative work using the tools of nonlinear dynamics and fractal analysis, our research team has shown that aging and disease are associated with a loss of complexity in the dynamics of a variety of physiologic systems. We have proposed that this loss of complexity can lead to reduced adaptive capacity, functional decline, and frailty. Nonlinear mathematical techniques that can quantify the dynamics of physiologic systems and their interactions may, therefore, help characterize the syndrome of frailty. Accordingly, we aim: 1) To determine crosssectionally in a representative population of elderly people aged 70 years and over, whether there is a relationship between 'frailty' and loss of complexity in the dynamics of multiple physiologic systems, including cardiovascular (interbeat (RR) intervals and blood pressure (BP)), cerebrovascular (cerebral blood flow velocity (BFV)), respiratory (interbreath intervals), and balance (center-of-pressure trajectories) control systems. We will also determine whether interactions between these systems degrade in frail elderly individuals by examining the correlations, coherence, phase, and transfer function gains between the dynamic measures of interacting systems (e.g., cardiac and respiratory, or systemic BP and cerebral BFV). 2) To determine whether a loss of complexity in cardiovascular, cerebrovascular, and/or balance dynamics, is associated with an impaired ability to adapt to common physiologic stresses imposed on these systems. We will examine specifically the relationships between: a) resting BP, RR intervals, or cerebral blood flow dynamics and their responses to posture change, and b) quiet standing center-of pressure trajectories and their response to a superimposed cognitive task. 3) To determine, longitudinally over a two-year follow-up period in the same population, whether reduced complexity in the dynamics of these physiologic systems at baseline, or loss of complexity in these systems over time, is predictive of the subsequent development of frailty, its component symptoms, and/or other measures of physical and cognitive functional decline. To achieve these aims we will process and analyze physiologic data that are being gathered from a well-characterized, prospectively followed, population-based sample of 800 elderly people over age 70 who are participating in an ongoing NIA-funded Program Project Grant (the HRCA/Harvard Research Nursing Home, P01-AG004390). The experience of the research team in clinical geriatric research, physiology, dynamic systems, and biostatistics, as well as the outstanding resources of the Hebrew Rehabilitation Center and Harvard Medical School will help assure the project's success.

Agency
National Institute of Health (NIH)
Institute
National Institute on Aging (NIA)
Type
Method to Extend Research in Time (MERIT) Award (R37)
Project #
5R37AG025037-06
Application #
8068886
Study Section
Special Emphasis Panel (NSS)
Program Officer
Joseph, Lyndon
Project Start
2004-09-01
Project End
2014-04-30
Budget Start
2011-06-15
Budget End
2012-04-30
Support Year
6
Fiscal Year
2011
Total Cost
$233,928
Indirect Cost
Name
Hebrew Rehabilitation Center for Aged
Department
Type
DUNS #
030832075
City
Boston
State
MA
Country
United States
Zip Code
02131
Zhou, Junhong; Lo, On-Yee; Lipsitz, Lewis A et al. (2018) Transcranial direct current stimulation enhances foot sole somatosensation when standing in older adults. Exp Brain Res 236:795-802
Zhou, Junhong; Lipsitz, Lewis; Habtemariam, Daniel et al. (2016) Sub-sensory vibratory noise augments the physiologic complexity of postural control in older adults. J Neuroeng Rehabil 13:44
Holmes, Matthew L; Manor, Brad; Hsieh, Wan-hsin et al. (2016) Tai Chi training reduced coupling between respiration and postural control. Neurosci Lett 610:60-5
Cohen, Marc A; Miller, Jessica; Shi, Xiaomei et al. (2015) Prevention Program Lowered The Risk Of Falls And Decreased Claims For Long-Term Services Among Elder Participants. Health Aff (Millwood) 34:971-7
Tchalla, Achille E; Wellenius, Gregory A; Sorond, Farzaneh A et al. (2015) Elevated circulating vascular cell Adhesion Molecule-1 (sVCAM-1) is associated with concurrent depressive symptoms and cerebral white matter Hyperintensities in older adults. BMC Geriatr 15:62
Hajjar, Ihab; Sorond, Farzaneh; Lipsitz, Lewis A (2015) Apolipoprotein E, carbon dioxide vasoreactivity, and cognition in older adults: effect of hypertension. J Am Geriatr Soc 63:276-81
Sorond, Farzaneh A; Tan, Can Ozan; LaRose, Sarah et al. (2015) Deferoxamine, Cerebrovascular Hemodynamics, and Vascular Aging: Potential Role for Hypoxia-Inducible Transcription Factor-1-Regulated Pathways. Stroke 46:2576-83
Kim, Dae Hyun; Grodstein, Francine; Newman, Anne B et al. (2015) Microvascular and Macrovascular Abnormalities and Cognitive and Physical Function in Older Adults: Cardiovascular Health Study. J Am Geriatr Soc 63:1886-93
Ward, Rachel E; Leveille, Suzanne G; Beauchamp, Marla K et al. (2015) Functional performance as a predictor of injurious falls in older adults. J Am Geriatr Soc 63:315-20
Pan, Wen-Chi; Eliot, Melissa N; Koutrakis, Petros et al. (2015) Ambient Temperature and Cerebrovascular Hemodynamics in the Elderly. PLoS One 10:e0134034

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