Dissertation/Thesis Abstract

Objectively measured physical activity levels and their relationship to physical fitness/function in heart failure patients
by Goodman, Alesia Michelle, M.S., Wake Forest University, 2011, 118; 1494567
Abstract (Summary)

PURPOSE: To describe levels of physical activity (PA) in those with heart failure and a preserved ejection fraction (HFpEF), examine the relationship of PA levels to other physical fitness/functional measures, and determine if there are significant differences between objectively measured PA levels and well-established prognostic measures in this population.

METHODS: Subjects were assessed at baseline of a RCT examining the effects of an exercise and/or weight loss intervention in older HFpEF patients. Inclusion for the RCT included: a HF Clinical Score of > 3, a normal ejection fraction (> 50%), a BMI of >30 kg/m2, and > 60 years of age. Peak oxygen consumption (VO2 peak) was obtained from a maximal effort exercise test on a motorized treadmill. Six-minute walk test was completed in a marked hallway using standard procedures. A uniaxial accelerometer (Lifecorder) was worn for 7 continuous days, and evaluated for adequate wear time and days. The average steps/day, physical activity energy expenditure (PAEE) in kcal/min, minutes of light (LPA) and moderate-vigorous physical activity (MVPA) were determined for each participant.

RESULTS: The 36 HFpEF subjects included in this study were older (mean age 68 yrs), mostly female (81%), and overweight/obese (mean BMI of 40.2 kg/m 2). The only variables that were significantly different between males and females were % fat, % lean body mass, leg press power, ejection fraction, and VO2 peak. No significant differences were seen between males and females for any of the PA measures. The average steps/day, PAEE, LPA, and MVPA were 3,475.0 ±1,303.4, 139.9 ± 58.6, 30.5 ± 11.1, and 8.8 ± 5.8 respectively. The 6-minute walk distance was significantly correlated with steps/day, PAEE, LPA, and MVPA (r = 0.52, 0.35, 0.45, and 0.38 respectively), and VO2 peak was significantly correlated with steps/day and LPA (r = 0.44 and 0.49 respectively). After prognostic clinical measures were dichotomized based on established criteria, the only significant difference was a greater number of steps/day for patients with a VO2 peak > 14 ml·kg·min -1.

CONCLUSION: These older, overweight, and mostly female HFpEF patients have very low levels of PA and are comparable to other chronic disease populations. The moderate correlations observed between physical fitness (VO2 peak and 6MW) and PA measures suggest that current levels only partially explain the functional differences observed in HFpEF patients. Finally, other than steps/day and VO2 peak, PA levels are not significantly different when compared on well-established dichotomous prognostic measures. Future studies should focus on the change in PA and change in physical fitness/function measures after exercise and/or weight loss interventions in this population.

Indexing (document details)
Advisor: Brubaker, Peter H.
Commitee: Berry, Michael J., Miller, Gary D.
School: Wake Forest University
Department: Health and Exercise Science
School Location: United States -- North Carolina
Source: MAI 49/06M, Masters Abstracts International
Subjects: Health sciences, Kinesiology, Epidemiology
Keywords: Accelerometer, Diastolic heart failure, Physical activity, Physical function
Publication Number: 1494567
ISBN: 9781124695495
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