Objectively measured physical activity and sedentary time of breast cancer survivors, and associations with adiposity: findings from NHANES (2003-2006).
OBJECTIVE
Obesity and physical inactivity are poor prognostic indicators for breast cancer. Studies to date have relied on self-report measures of physical activity, which tend mainly to assess moderate-to-vigorous intensity leisure-time physical activity. We report the cross-sectional associations of objectively assessed physical activity and sedentary time with adiposity in a sample of breast cancer survivors from the United States.


METHODS
One hundred and eleven women from the National Health and Nutrition Examination Survey (NHANES) 2003-2004 and 2005-2006 reported a history of breast cancer. Participants wore an accelerometer for 7 days, and activity levels were summarized as moderate-to-vigorous intensity (accelerometer counts/min > or =1,952), light intensity (counts/min 100-1,951), and sedentary time (counts/min <100). Anthropometric measures were taken by study staff at examination centers.


RESULTS
Participants spent the majority of their day in sedentary time (66%) or in light intensity activities (33%). Log moderate-to-vigorous intensity physical activity was negatively associated with adiposity (waist circumference beta = -9.805 [95% CI: -15.836, -3.775]; BMI beta = -3.576 [95% CI: -6.687, -0.464]). Light intensity physical activity was negatively associated with adiposity; however, the fully adjusted models did not retain statistical significance. Similarly, sedentary time was positively associated with adiposity, but the fully adjusted models were not statistically significant.


CONCLUSIONS
This is the first study to describe the objectively assessed physical activity and sedentary time of breast cancer survivors. Increasing moderate-to-vigorous and light intensity physical activity, and decreasing sedentary time, may assist with weight management and improve other metabolic health outcomes for breast cancer survivors.
Lynch
Brigid M
BM
Cancer Prevention Research Centre, School of Population Health, The University of Queensland, Brisbane, QLD, Australia. b.lynch@sph.uq.edu.au
Dunstan
David W
DW
Healy
Genevieve N
GN
Winkler
Elisabeth
E
Eakin
Elizabeth
E
Owen
Neville
N
D050154:Adiposity / Q000502:physiology*; D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D015992:Body Mass Index; D001835:Body Weight / Q000502:physiology; D001943:Breast Neoplasms / Q000097:blood / Q000503:physiopathology*; D003430:Cross-Sectional Studies; D015444:Exercise / Q000502:physiology*; D005260:Female; D006306:Health Surveys; D006801:Humans; D007328:Insulin / Q000097:blood; D008875:Middle Aged; D009749:Nutrition Surveys; D010809:Physical Fitness / Q000502:physiology; D012044:Regression Analysis; D017741:Survivors; D014481:United States
D007328:Insulin