Contrasting characteristics of daily physical activity in older adults by cancer history.

BACKGROUND: Using objectively collected physical activity (PA) data from the Baltimore Longitudinal Study of Aging, the authors tested whether patterns of daily activity and sedentary time differed by cancer survivorship in older adults.
METHODS: In total, 659 participants (mean age ± standard deviation, 71 ± 10 years; 51% women) who had self-reported information on cancer history were instructed to wear an accelerometer for 7 consecutive days. Accelerometer data were summarized into: 1) PA volume and 2) activity fragmentation (interrupted activity), expressed as both continuous and as dichotomized (low and high) variables. Participants were categorized into 4 groups by cross-classification of dichotomous PA volume and fragmentation. Multiple regression models were used to estimate differences in PA patterns by cancer history.
RESULTS: Cancer survivors averaged 0.12 fewer log-transformed activity counts per day (standard error, 0.05; P = .02) than individuals who reported no history of cancer after adjusting for demographics, behavioral factors, and comorbidities. Although fragmentation did not differ by cancer survivorship in the continuous model (P = .13), cancer survivorship was associated with 77% greater odds (odds ratio, 1.77; 95% confidence interval, 1.11-2.82) of having high (vs low) fragmentation and 94% greater odds (odds ratio, 1.94; 95% confidence interval, 1.13-3.33) of having combined low PA/high fragmentation (vs high PA/low fragmentation) relative to those with no cancer history.
CONCLUSIONS: The current findings suggest that cancer survivors engage in lower total daily PA and that they perform this activity in a more fragmented manner compared with adults without a history of cancer. These results may reflect the onset and progression of a low-activity phenotype that is more vulnerable to heightened levels of fatigue and functional decline with aging.