Date of Award

January 2015

Document Type

Open Access Thesis

Degree Name

Master of Public Health (MPH)

Department

School of Public Health

First Advisor

Melinda L. Irwin

Abstract

The use of aromatase inhibitors (AIs) has been associated with increased risk of cardiovascular disease and unfavorable changes in lipid profile in postmenopausal breast cancer survivors. In other populations, physical activity has been shown to successfully reduce CVD risk and improve lipid parameters. The Hormones and Physical Exercise (HOPE) study was a yearlong randomized trial examining the impact of exercise vs. usual care on AI-associated side effects. This analysis examined the effect of exercise on lipid profiles among HOPE participants.

We enrolled 121 physically inactive (<90 min/wk of aerobic activity and no strength training) postmenopausal breast cancer survivors receiving an AI for at least 6 months. Participants were randomly assigned to exercise (150 min/wk of aerobic exercise and supervised strength training 2x/wk) or to usual care. Fasting blood samples (>12 hours) were collected at the baseline, 6- and 12-month clinic visits. Intervention effects were evaluated using generalized linear models, with change from baseline to 6 months and 12 months as the primary end points.

Over 12 months, women randomized to exercise increased their exercise by 159 (SD 136) minutes per week and decreased their body weight by 2.4% (SD 5.4%). LDL/HDL ratio increased by 3% at 6 months among women randomized to exercise versus a 6% decrease among those in the attention control group (p = 0.036). Likewise, TC/HDL ratio increased by 2% at 6 months among women randomized to exercise versus a 5% decrease among those in the attention control group (p = 0.038). A dose-response inverse relation between attendance to supervised exercise sessions and triglycerides was also observed (p = 0.047).

We observed an unfavorable effect of exercise on the lipid ratios. Further research is needed to examine the impact of exercise on lipid levels and CVD risk in breast cancer survivors initiating AI use.

Comments

This is an Open Access Thesis.

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