L. Broughton, S. Mueller, A. Wiesemann, K. Christison, C. Dumke, FACSM

University of Montana, Missoula, MT.

Postmenopausal (PM) women who have undergone treatment for breast cancer (BC) are at an increased risk for cardiovascular disease due to declines in estrogen levels and vascular toxicity from anthracycline and taxane-based chemotherapies. PURPOSE: Compare the cardiovascular response to acute aerobic exercise in healthy PM women (HPM) and PM women after chemotherapeutic treatment from BC (BPM). METHODS: 4 PM women with a history of breast cancer (51 ± 6 yr, 59.0 ± 4.2 kg, 33.9 ± 2.6 ml·kg-1·min-1) and 4 apparently healthy PM women (66 ± 3 yr, 64.2 ± 1.1 kg, 29.0 ± 2.3 ml·kg-1·min-1) completed two visits to the lab. The first visit consisted of a DEXA scan to measure bone mineral density (BMD) and body composition, and a maximal aerobic capacity test (VO2max) to establish workload. The second visit measured baseline nude body weight (NBW), systolic (SBP) and diastolic (DBP) blood pressure, and blood samples for hematocrit (Hct). Subjects then completed a 30-min steady state exercise bout at 70% of VO2max where measures of VO2, rate of perceived exertion (RPE), and heart rate (HR) were taken every 10 min. Water was prescribed at 3 ml· kg of fat free mass-1·30 min-1. Postexercise, BP was repeated, followed by a 60-min rest. After rest, BP, Hct and NBW were repeated. HR, RPE, VO2, SBP, DBP were analyzed using a 2x3 ANOVA. NBW and Hct were analyzed using a 2x2 ANOVA. Body composition and BMD were analyzed using independent sample t-tests. Data presented as mean ± SEM. RESULTS: No significant differences were seen between groups for body weight, VO2max, or BMD. BPM had significantly lower body fat (35.0 ± 1.1 vs 39.8 ± 1.0%, p=0.009) and visceral adipose tissue (2.8 ± 0.4 vs 5.8 ± 1.0 kg, p=0.025) compared to HPM. Main effect of time was seen in max HR (127.5 ± 4.7 vs 118.5 ± 8.7 bpm, p=0.024) during the trial. Main effect of group was seen in VO2 during exercise (19.7 ± 0.9 vs 21.2 ± 0.9 ml·kg-1·min-1, p=0.022). No main effects of time, group, or interaction were seen in NBW, Hct, RPE, SBP or DBP. CONCLUSION: These early pilot data suggest that despite the toxicity of chemotherapy, there are no significant differences in the cardiovascular responses to acute aerobic exercise between HPM women and BPM. Additionally, BPM had lower whole-body fat and visceral fat than the HPM, which has positive cardiometabolic associations.

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