TY - JOUR
T1 - Influence of insulin-like growth factors on the strength of the relation of vitamin D and calcium intakes to mammographic breast density
AU - Diorio, Caroline
AU - Bérubé, Sylvie
AU - Byrne, Celia
AU - Mâsse, Benoît
AU - Hébert-Croteau, Nicole
AU - Yaffe, Martin
AU - Coté, Gary
AU - Pollak, Michael
AU - Brisson, Jacques
PY - 2006/1/1
Y1 - 2006/1/1
N2 - Diets with higher vitamin D and calcium contents were found associated with lower mammographic breast density and breast cancer risk in premenopausal women. Because laboratory studies suggest that the actions of vitamin D, calcium, insulin-like growth factor (IGF)-I, and IGF-binding protein-3 (IGFBP-3) on human breast cancer cells are interrelated, we examined whether IGF-I and IGFBP-3 levels could affect the strength of the association of vitamin D and calcium intakes with breast density. Among 771 premenopausal women, breast density was measured by a computer-assisted method, vitamin D and calcium intakes by a food frequency questionnaire, and levels of plasma IGF-I and IGFBP-3 by ELISA methods. Multivariate linear regression models were used to examine the associations and the interactions. The negative associations of vitamin D or calcium intakes with breast density were stronger among women with IGF-I levels above the median (β = -2.8, P = 0.002 and β = -2.5, P = 0.002, respectively) compared with those with IGF-I levels below or equal to the median (β = -0.8, P = 0.38 and β = -1.1, P = 0.21; P interaction = 0.09 and 0.16, respectively). Similar results were observed within levels of IGFBP-3 (Pinteraction = 0.06 and 0.03, respectively). This is the first study to report that the negative relation of vitamin D and calcium intakes with breast density may be seen primarily among women with high IGF-I or high IGFBP-3 levels. Our findings suggest that the IGF axis should be taken into account when the effects of vitamin D and calcium on breast density (and perhaps breast cancer risk) are examined at least among premenopausal women.
AB - Diets with higher vitamin D and calcium contents were found associated with lower mammographic breast density and breast cancer risk in premenopausal women. Because laboratory studies suggest that the actions of vitamin D, calcium, insulin-like growth factor (IGF)-I, and IGF-binding protein-3 (IGFBP-3) on human breast cancer cells are interrelated, we examined whether IGF-I and IGFBP-3 levels could affect the strength of the association of vitamin D and calcium intakes with breast density. Among 771 premenopausal women, breast density was measured by a computer-assisted method, vitamin D and calcium intakes by a food frequency questionnaire, and levels of plasma IGF-I and IGFBP-3 by ELISA methods. Multivariate linear regression models were used to examine the associations and the interactions. The negative associations of vitamin D or calcium intakes with breast density were stronger among women with IGF-I levels above the median (β = -2.8, P = 0.002 and β = -2.5, P = 0.002, respectively) compared with those with IGF-I levels below or equal to the median (β = -0.8, P = 0.38 and β = -1.1, P = 0.21; P interaction = 0.09 and 0.16, respectively). Similar results were observed within levels of IGFBP-3 (Pinteraction = 0.06 and 0.03, respectively). This is the first study to report that the negative relation of vitamin D and calcium intakes with breast density may be seen primarily among women with high IGF-I or high IGFBP-3 levels. Our findings suggest that the IGF axis should be taken into account when the effects of vitamin D and calcium on breast density (and perhaps breast cancer risk) are examined at least among premenopausal women.
UR - http://www.scopus.com/inward/record.url?scp=31544467889&partnerID=8YFLogxK
U2 - 10.1158/0008-5472.CAN-05-1959
DO - 10.1158/0008-5472.CAN-05-1959
M3 - Article
C2 - 16397276
AN - SCOPUS:31544467889
SN - 0008-5472
VL - 66
SP - 588
EP - 597
JO - Cancer Research
JF - Cancer Research
IS - 1
ER -