Longitudinal associations of sedentary behavior and physical activity with body composition in colorectal cancer survivors up to 2 years post treatment

Purpose We investigated longitudinal associations of sedentary behavior, light-intensity physical activity (LPA) and moderate-to-vigorous physical activity (MVPA) with body composition in colorectal cancer (CRC) survivors, between 6 weeks and 24 months post treatment. In addition, we explored whether body composition mediated associations of sedentary behavior and MVPA with fatigue. Methods A prospective cohort study was conducted in 459 stage I-III CRC patients recruited at diagnosis. Measurements were performed of accelerometer-assessed sedentary time (hours/day), self-reported LPA and MVPA (hours/week), anthropometric assessment of body mass index (BMI), waist circumference and fat percentage (measures of adiposity), and muscle circumference and handgrip strength (measures of muscle mass/function) repeated at 6 weeks, and 6, 12 and 24 months post treatment. Longitudinal associations of sedentary time and physical activity with body composition were analyzed using confounder-adjusted linear mixed models. Mediation analyses were performed to explore the role of body mass index (BMI) and handgrip strength as mediators in associations of sedentary time and MVPA with fatigue. Results Less sedentary time and LPA were, independent of MVPA, longitudinally associated with increased handgrip strength, but not with measures of adiposity. More MVPA was associated with increased adiposity and increased handgrip strength. Higher BMI partly mediated associations between higher sedentary time and more fatigue. Conclusion Within the first two years after CRC treatment, changes in sedentary behavior, physical activity and body composition are interrelated and associated with fatigue. Intervention studies are warranted to investigate causality.

Automated summary

This study examined the longitudinal associations of sedentary behavior, light-intensity physical activity (LPA), and moderate-to-vigorous physical activity (MVPA) with body composition in colorectal cancer survivors. The results showed that less sedentary time and LPA were associated with increased handgrip strength, independent of MVPA. However, they were not associated with measures of adiposity. On the other hand, more MVPA was associated with increased adiposity and handgrip strength. Additionally, higher BMI partly mediated the associations between higher sedentary time and more fatigue.