Accelerometer-assessed Standing Time With And Without Ambulation In Relation To Cancer Incidence And Mortality: The Womens Health Accelerometry Collaboration

Higher accelerometer-measured sedentary behavior is associated with increased cancer risk. However, prospective associations with other low energy expenditure activities such as standing have not been explored. PURPOSE: To examine the associations between accelerometer-measured Two-Level Behavior Classification (TLBC) algorithm-classified daily standing time, both with and without ambulation, and incidence of nonfatal and fatal cancers among women in the Women’s Health Accelerometry Collaboration (WHAC). METHODS: The WHAC comprised 22,097 postmenopausal women (mean age = 73.3, SD = 6.7 years) including 16,388 from the Women’s Health Study and 5,709 from the Women’s Health Initiative Objective Physical Activity and Cardiovascular Health Study. From 2011-2015, women wore an ActiGraph GT3X+ on the hip for one week and were subsequently followed for a mean 8.5 years. Standing with ambulation (i.e., standing and moving in a confined space such as performing housework or gardening) and without ambulation (i.e., standing still) were computed using the TLBC algorithm (both average minutes/day). Analyses were conducted for any incident cancer excluding non-melanoma skin cancer (n = 1,861 cases), fatal cancer (n = 601), and separately by cancer type including breast (n = 632), colon (n = 116), endometrial (n = 128), and lung cancers (n = 207). Adjusted hazard ratios (HRs) and 95% confidence intervals (CIs) were calculated using Cox regression. RESULTS: Overall, women spent 220 min/day (SD = 91) standing with ambulation and 48 min/day (SD = 37) standing without ambulation. There was no association for standing with ambulation (HR 0.97, 95% CI: 0.92, 1.02 per SD increase), but a statistically significant 6% lower hazard of incident cancer (HR 0.94, 95% CI: 0.90, 0.99) per SD increase in standing without ambulation. For fatal cancer, HRs for standing with and without ambulation were 0.96 (95% CI: 0.88, 1.04) and 0.92 (95% CI: 0.85, 1.00), respectively. For standing without ambulation, similar statistically significant associations were found with breast and lung cancer, but not with colon or endometrial cancer. CONCLUSIONS: For postmenopausal women, greater amounts of time spent standing, particularly without ambulation, may be associated with lower risk of cancer and fatal cancers. T32 HL079891