Effects of Lifestyle Interventions on Cardiometabolic Health in non-physically active Breast Cancer Survivors at risk of recurrence: a randomized controlled trial

INTRODUCTION: Impaired cardio-metabolism, fat accumulation, and low-grade chronic inflammation are associated with an increased risk of breast cancer (BC) development and recurrence [1-3]. Moreover, adjuvant treatments for BC negatively impact maximal oxygen uptake (VO2max) [4]. Interventions aiming at improving metabolic syndrome and cardiorespiratory fitness in BC survivors (BCS) are needed to reduce the risk of comorbidities and improve BC outcomes. This randomized controlled trial assessed the effects of a 12-week aerobic exercise intervention on metabolic syndrome related risk factors and VO2max in sedentary BCS. METHODS: 41 BCS (women; stages 0-II; non-metastatic; age 51.6±7.0 years; non-physically active) with a risk factor for recurrence due to metabolic or endocrine disorders underwent a 12-week lifestyle intervention based on nutrition and exercise. Women were randomly allocated to an intervention (IA) or a control (CA) arm. In addition to counselling on diet habits and physical activity, which were provided to both arms, IA performed a 12-week remotely (1 session/week) and on-site (2 sessions/week) supervised aerobic exercise training program having progressive increases in exercise intensity (40%-70% of heart rate reserve) and duration (20-60 min). Participants estimated VO2max, út mass (úT), glycemia (GLY), LDL, and triglycerides (TRI) were assessed before (t0) and after (t1) the lifestyle interventions. A RM-MANOVA (α=0.05), followed by univariate ANOVAs, were used to assess the effects of time (t0 and t1, repeated measure), intervention (IA and CA), and their interaction on VO2max, úT, GLY, LDL, and TRI. RESULTS: Significant multivariate effects were found for time (p<0.001) and its interaction with intervention (p=0.019), whereas no significant multivariate effect was found for intervention (p=0.401). Univariate analyses showed a significant effect of time on LDL (t0=132.7±30.7, t1=122.3±26.9, p=0.003) and úT (t0=31.7±7.1, t1=29.9±6.5, p<0.001) levels of both groups, which decreased, while no significant changes over time were found on VO2max (p=0.342), GLY (p=0.875), and TRI (p=0.348) levels. The interaction between time and intervention was significant only on the VO2max levels (p=0.037), which increased in IA (t0=31.0±6.7, t1=32.5±6.0) and slightly decreased in CA (t0=31.7±4.5, t1=31.1±4.7), whereas no significant differences were found between IA and CA GLY (p=0.407), LDL (p=0.080), TRI (p=0.441), and úT (p=0.128) changes over time. CONCLUSION: Lifestyle interventions attenuated metabolic syndrome risk factors by reducing LDL and úT. However, only a structured and supervised exercise prescription improved VO2max in BCS, supporting the inclusion of supervised clinical exercise programs into BCS treatment and survivorship care plans. References: 1. Pasanisi P, et al., Int J Cancer, 2006 2. Calip GS, et al., Breast Cancer Res Treat, 2014 3. Lauby-Secretan B, et al., N Engl J Med, 2016 4. Peel AB, et al., J Am Heart Assoc, 2014