Reallocating Time Between Sleep, Sedentary Time, And Physical Activity On Quality Of Life In Cancer Survivors

Abstract

PURPOSE: Increasing time in moderate-vigorous physical activity (MVPA) and reducing time in sedentary behaviors (SB) can improve quality of life (QOL) in cancer survivors (CS). However, these behaviors only account for a small portion of the day, neglecting other important health behaviors like sleep and light PA. When examining the effects of these behaviors on QOL, it is important to account for their interdependent nature within the confines of the 24-hour day (i.e., you must decrease time in one activity to increase time in another). This study examined the effect of reallocating time between sleep, SB, light PA and MVPA on QOL in a mixed sample of CS. METHODS: A cross-sectional evaluation of adult CS within five-years of completing active cancer treatment(s). Participants concurrently wore the activPAL™ accelerometer to measure SB, light PA and MVPA, and the Actiwatch-2 to measure sleep duration for 7-days, 24-hours per day. QOL was measured using the Functional Assessment of Cancer Therapy-General (FACT-G). FACT-G scores range from 0-108, a difference of 4 points is considered clinically meaningful, and higher scores indicate better QOL. Isotemporal substitution methods in linear regression models were used to examine the effect of 30-minute time reallocations on total QOL. RESULTS: Participants (N=73) were M=53±13 years old, mostly female (75.7%), and diagnosed with colorectal (33.8%) breast (29.7%), leukemia/lymphoma (9.5%), or other (27.0%) cancer. Average QOL score was 87.0±15.3 (range = 41-107). No time reallocations were statistically significant, however, clinically meaningful associations (i.e., lower QOL) were observed for reallocating 30 minutes from MVPA to sleep (-4.42), SB (-4.32), or light PA (-5.06). CONCLUSION: Findings suggest that moving time away from MVPA may negatively impact QOL but did not reach statistical significance. These findings are congruent with previous literature which has established the important role of MVPA for QOL in CS. Future studies should evaluate reallocating time among a sample of survivors presenting with poor versus good QOL to guide intervention development.