TY - JOUR
T1 - Levels of C-peptide and mammographic breast density
AU - Diorio, Caroline
AU - Pollak, Michael
AU - Byrne, Celia
AU - Mâsse, Benoît
AU - Hébert-Croteau, Nicole
AU - Yaffe, Martin
AU - Coté, Gary
AU - Bérubé, Sylvie
AU - Brisson, Jacques
PY - 2005/11
Y1 - 2005/11
N2 - Members of the insulin-like growth factor family have been associated with breast cancer risk and mammographic breast density, one of the strongest known breast cancer risk indicators. The aim of this cross-sectional study was to examine the association of levels of C-peptide (a marker of insulin secretion) with mammographic breast density among 1,499 healthy women recruited during screening mammography examinations. At time of mammography, blood samples and time since last meal were collected. Plasma C-peptide levels were measured by ELISA method, and mammographic breast density by a computer-assisted method. Spearman's partial correlation coefficients, adjusting for age and time since last meal (when necessary), were used to evaluate the associations. High body mass index and waist-to-hip ratio measurements were independently correlated with high levels of C-peptide (r s = 0.173 and r s = 0.252, respectively; P < 0.0001) or low breast density (r s = -0.389 and r s = -0.142, respectively; P < 0.0001). High levels of C-peptide were correlated with low breast density (r s = -0.210, P < 0.0001). However, the strength of the negative correlation was substantially reduced and was no longer significant after further adjustment for body mass index and waist-to-hip ratio (r s = -0.022, P = 0.41). These results suggest that C-peptide levels are not associated with breast density after complete adjustment for adiposity. Thus, the insulin/C-peptide-breast density relation does not seem to mirror the insulin/C-peptide-breast cancer association.
AB - Members of the insulin-like growth factor family have been associated with breast cancer risk and mammographic breast density, one of the strongest known breast cancer risk indicators. The aim of this cross-sectional study was to examine the association of levels of C-peptide (a marker of insulin secretion) with mammographic breast density among 1,499 healthy women recruited during screening mammography examinations. At time of mammography, blood samples and time since last meal were collected. Plasma C-peptide levels were measured by ELISA method, and mammographic breast density by a computer-assisted method. Spearman's partial correlation coefficients, adjusting for age and time since last meal (when necessary), were used to evaluate the associations. High body mass index and waist-to-hip ratio measurements were independently correlated with high levels of C-peptide (r s = 0.173 and r s = 0.252, respectively; P < 0.0001) or low breast density (r s = -0.389 and r s = -0.142, respectively; P < 0.0001). High levels of C-peptide were correlated with low breast density (r s = -0.210, P < 0.0001). However, the strength of the negative correlation was substantially reduced and was no longer significant after further adjustment for body mass index and waist-to-hip ratio (r s = -0.022, P = 0.41). These results suggest that C-peptide levels are not associated with breast density after complete adjustment for adiposity. Thus, the insulin/C-peptide-breast density relation does not seem to mirror the insulin/C-peptide-breast cancer association.
UR - http://www.scopus.com/inward/record.url?scp=28644437064&partnerID=8YFLogxK
U2 - 10.1158/1055-9965.EPI-05-0466
DO - 10.1158/1055-9965.EPI-05-0466
M3 - Article
C2 - 16284393
AN - SCOPUS:28644437064
SN - 1055-9965
VL - 14
SP - 2661
EP - 2664
JO - Cancer Epidemiology Biomarkers and Prevention
JF - Cancer Epidemiology Biomarkers and Prevention
IS - 11 I
ER -