TY - JOUR
T1 - Associations between time spent sitting and cancer-related biomarkers in postmenopausal women
T2 - an exploration of effect modifiers
AU - Paxton, Raheem J.
AU - Jung, Su Yon
AU - Vitolins, Mara Z.
AU - Fenton, Jenifer
AU - Paskett, Electra
AU - Pollak, Michael
AU - Hays-Grudo, Jennifer
AU - Hursting, Stephen D.
AU - Chang, Shine
N1 - Publisher Copyright:
© 2014, Springer International Publishing Switzerland.
PY - 2014/10/31
Y1 - 2014/10/31
N2 - Purpose: Despite evidence that prolonged periods of sitting may influence biological mediators of cancer development, few studies have considered these relationships in a cancer-specific context.Methods: This cross-sectional study included 755 postmenopausal women enrolled in an ancillary study of the Women’s Health Initiative. Plasma levels of Insulin-like growth factor-I (IGF-I), IGF-binding protein-3, leptin, insulin, C-peptide, C-reactive protein (CRP), and Interleukin (IL)-6 were measured. The time spent sitting per day was categorized as quartiles (Qs). The relationships between sedentary time and biomarkers were modified by race, physical activity, and exogenous estrogen use.Results: IGF-I levels among African American (AA) women were higher than those of white women across the Qs of sedentary time. Likewise, IL-6 levels in AA women were higher than those in white women at Q3 and Q4 of sedentary time. IGFBP-3 levels were higher and insulin levels were lower across the Qs of sedentary time among women meeting guidelines for physical activity than women who were not. Additionally, CRP levels were higher among estrogen users than nonusers at Q1, Q2, and Q4 of sedentary time.Conclusions: These results suggest that relationship between time spent sitting and cancer-related biomarkers may not be simply linear, but differ in the context of effect modifiers.
AB - Purpose: Despite evidence that prolonged periods of sitting may influence biological mediators of cancer development, few studies have considered these relationships in a cancer-specific context.Methods: This cross-sectional study included 755 postmenopausal women enrolled in an ancillary study of the Women’s Health Initiative. Plasma levels of Insulin-like growth factor-I (IGF-I), IGF-binding protein-3, leptin, insulin, C-peptide, C-reactive protein (CRP), and Interleukin (IL)-6 were measured. The time spent sitting per day was categorized as quartiles (Qs). The relationships between sedentary time and biomarkers were modified by race, physical activity, and exogenous estrogen use.Results: IGF-I levels among African American (AA) women were higher than those of white women across the Qs of sedentary time. Likewise, IL-6 levels in AA women were higher than those in white women at Q3 and Q4 of sedentary time. IGFBP-3 levels were higher and insulin levels were lower across the Qs of sedentary time among women meeting guidelines for physical activity than women who were not. Additionally, CRP levels were higher among estrogen users than nonusers at Q1, Q2, and Q4 of sedentary time.Conclusions: These results suggest that relationship between time spent sitting and cancer-related biomarkers may not be simply linear, but differ in the context of effect modifiers.
KW - Cancer-relevant biomarkers
KW - Effect modifier
KW - Postmenopausal women
KW - Sedentary behavior
UR - http://www.scopus.com/inward/record.url?scp=84911970294&partnerID=8YFLogxK
U2 - 10.1007/s10552-014-0434-y
DO - 10.1007/s10552-014-0434-y
M3 - Article
C2 - 25238978
AN - SCOPUS:84911970294
SN - 0957-5243
VL - 25
SP - 1427
EP - 1437
JO - Cancer Causes and Control
JF - Cancer Causes and Control
IS - 11
ER -