title: Objectively measured sedentary time is related to quality of life among cancer survivors.
abstract: OBJECTIVE
  While exercise has been shown to be beneficial in improving health-related quality of life (HRQOL) among cancer survivors, evidence is limited on the independent role of sedentary behavior. We examined how objectively measured sedentary time was associated with HRQOL among long-term cancer survivors.
  
  
  METHODS
  This cross-sectional study included 54 cancer survivors, on average 3.4 years postdiagnosis, who were enrolled into an exercise trial designed to improve cognitive function. At baseline, we measured sedentary time and moderate-vigorous intensity physical activity with the ActivPal, cardiorespiratory fitness with treadmill testing, and self-reported HRQOL with an established scale (SF-36). In multivariate models, we regressed HRQOL on sedentary time (percent of waking time spent sitting and lying).
  
  
  RESULTS
  Survivors with higher sedentary time had significantly poorer physical functioning (β = -0.50, p = 0.028), general health (β = -0.75, ptrend = 0.004), and physical summary scores (β = -0.34, p = 0.003). We did not observe associations between sedentary time and role-physical (p = 0.342), bodily-pain (p = 0.117), vitality (p = 0.095), social functioning (p = 0.407), role-emotional (p = 0.509), mental health (p = 0.494), or mental summary scores (p = 0.527).
  
  
  CONCLUSIONS
  In this cross-sectional study of cancer survivors, we observed deleterious associations between sedentary time and aspects of physical HRQOL. Future prospective studies of sedentary time and HRQOL are needed to establish temporality and to facilitate the design of effective health promotion interventions for cancer survivors.
authors: Applied Research Program, Division of Cancer Control and Population Sciences, National Cancer Institute, Bethesda, Maryland, United States of America.
authors: Stephanie M
authors: SM
authors: George
authors: Office of Cancer Survivorship, National Cancer Institute, Bethesda, Maryland, United States of America.
authors: Catherine M
authors: CM
authors: Alfano
authors: Vanderbilt Dayani Center for Health and Wellness, Vanderbilt University Medical Center, Nashville, Tennessee, United States of America.
authors: Jay
authors: J
authors: Groves
authors: Vanderbilt Dayani Center for Health and Wellness, Vanderbilt University Medical Center, Nashville, Tennessee, United States of America.
authors: Zafer
authors: Z
authors: Karabulut
authors: Department of Psychiatry, Vanderbilt University School of Medicine, Nashville, Tennessee, United States of America.
authors: Kirsten L
authors: KL
authors: Haman
authors: Division of Hematology/Oncology, Department of Medicine, Vanderbilt University, Nashville, Tennessee, United States of America.
authors: Barbara A
authors: BA
authors: Murphy
authors: Nutritional Epidemiology Branch, Division of Cancer Epidemiology and Genetics, National Cancer Institute, Bethesda, Maryland, United States of America.
authors: Charles E
authors: CE
authors: Matthews
mesh_terms: D003430:Cross-Sectional Studies; D005260:Female; D006801:Humans; D008297:Male; D008875:Middle Aged; D009043:Motor Activity; D009369:Neoplasms; D011788:Quality of Life; D017741:Survivors; D013997:Time Factors