Abstract
PURPOSE: This study aimed to explore the relationship between objectively measured physical activity and cognitive functioning in breast cancer survivors. METHODS: Participants were 136 postmenopausal breast cancer survivors. Cognitive functioning was assessed using a comprehensive computerized neuropsychological test. Seven-day physical activity was assessed using hip-worn accelerometers. Linear regression models examined associations of minutes per day of physical activity at various intensities on individual cognitive functioning domains. The partially adjusted model controlled for primary confounders (model 1), and subsequent adjustments were made for chemotherapy history (model 2) and body mass index (BMI) (model 3). Interaction and stratified models examined BMI as an effect modifier. RESULTS: Moderate-to-vigorous physical activity (MVPA) was associated with information processing speed. Specifically, 10 min of MVPA was associated with a 1.35-point higher score (out of 100) on the information processing speed domain in the partially adjusted model and a 1.29-point higher score when chemotherapy was added to the model (both p < 0.05). There was a significant BMI × MVPA interaction (p = 0.051). In models stratified by BMI (<25 vs. ≥25 kg/m(2)), the favorable association between MVPA and information processing speed was stronger in the subsample of overweight and obese women (p < 0.05) but not statistically significant in the leaner subsample. Light-intensity physical activity was not significantly associated with any of the measured domains of cognitive function. CONCLUSIONS: MVPA may have favorable effects on information processing speed in breast cancer survivors, particularly among overweight or obese women. IMPLICATIONS FOR CANCER SURVIVORS: Interventions targeting increased physical activity may enhance aspects of cognitive function among breast cancer survivors.