Browsing by Author "Sledge, Jeffrey S."

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    Impact of primary breast cancer therapy on energetic capacity and body composition
    (Springer, 2018-11) Ballinger, Tarah J.; Reddy, Anurag; Althouse, Sandra K.; Nelson, Emily M.; Miller, Kathy D.; Sledge, Jeffrey S.; Medicine, School of Medicine
    PURPOSE: This observational study was designed to measure baseline energy parameters and body composition in early-stage breast cancer patients, and to follow changes during and after various modalities of treatment. This will provide information to aid in the development of individualized physical activity intervention strategies. METHODS: Patients with newly diagnosed stage 0-III breast cancer were enrolled into three cohorts: A (local therapy alone), B (endocrine therapy), or C (chemotherapy with or without endocrine therapy). At baseline, 6 months, and 12 months, subjects underwent a stationary bicycle protocol to assess power generation and DEXA to assess body composition. RESULTS: Eighty-three patients enrolled. Patients had low and variable levels of power generation at baseline (mean power per kilogram lean mass 1.55 W/kg, SD 0.88). Power normalized to lean body mass (W/kg) decreased significantly, and similarly, by 6 months in cohorts B (1.42-1.04 W/kg, p = 0.008) and C (1.53-1.18 W/kg, p < 0.001). In all cohorts, there was no recovery of power generation by 12 months. Cohort C lost lean body mass (- 1.5 kg, p = 0.007), while cohort B maintained lean body mass (- 0.2 kg, p = 0.68), despite a similar trajectory in loss of power. Seven patients developed sarcopenia during the study period, including four patients who did not receive any chemotherapy (cohort B). CONCLUSIONS: The stationary bike protocol was feasible, easy, and acceptable to patients as a way to measure energetic capacity in a clinical setting. Early-stage breast cancer patients had low and variable levels of power generation, which worsened following primary therapy and did not show evidence of 'spontaneous recovery' by 12 months. Effective physical activity interventions will need to be personalized, accounting for both baseline ability and the effect of treatment.
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    A Personalized, Dynamic Physical Activity Intervention Is Feasible and Improves Energetic Capacity, Energy Expenditure, and Quality of Life in Breast Cancer Survivors
    (Frontiers Media, 2021-04-12) Ballinger, Tarah J.; Althouse, Sandra K.; Olsen, Timothy P.; Miller, Kathy D.; Sledge, Jeffrey S.; Medicine, School of Medicine
    Purpose: Despite survival and quality of life benefits associated with physical activity, many breast cancer survivors remain inactive. Effective, sustainable interventions must account for individual differences in capability, motivation, and environment. Here, we evaluate the feasibility, mechanics, and efficacy of delivering an individualized, dynamic intervention to increase energetic capacity and energy expenditure. Methods: Stage 0-III breast cancer patients who had completed primary treatment were enrolled. Prior to the intervention, detailed movement data was collected with a wearable GPS and accelerometer for 3 weeks to establish baseline activity. Movement data was collected continuously throughout the 12-week intervention, during which patients received electronically delivered, tailored, dynamic activity "prescriptions", adjusted based on demonstrated individual capability, daily movement in their environment, and progress. Results: Of 66 enrolled, 57 participants began and completed the intervention. The intervention resulted in significant improvements in average steps (+558 steps/day, p = 0.01), energetic capacity measured by power generation on a stationary bicycle (1.76 to 1.99 W/kg lean mass, p < 0.01), and quality of life (FACT-B TOI, 72.8 to 74.8, p = 0.02). The greatest improvement in functional energetic capacity was seen in the lowest performing tertile at baseline (0.76 to 1.12 W/kg, p < 0.01). Discussion: Wearable technology delivery of personalized activity prescriptions based on individual capability and movement behaviors demonstrates feasibility and early effectiveness. The high variability seen in baseline activity and function, as well as in response to the intervention, supports the need for future work in precision approaches to physical activity (NCT03158519).