title: Prospective study on the role of glucose metabolism in breast cancer occurrence.
abstract: High circulating glucose, insulin resistance and obesity appear to be associated with increased risk of breast cancer (BC). We sought further insight into the relation of these variables to BC. We assessed associations of BC risk with serum fasting glucose, insulin, homeostasis model assessment-insulin resistance (HOMA-IR) index and sex-binding hormone globulin (SHBG) in women recruited to the ORDET cohort who gave blood samples in 1987-1992. After a median 13.5 years of follow-up, 356 women developed BC. Four matched controls per case were selected by incidence density sampling, and rate ratios (RR) were estimated by conditional logistic regression. Women in the highest glucose quartile had a significantly greater risk of BC than those in the lowest glucose quartile (RR 1.63; 95% CI: 1.14-2.32; p for trend of 0.003). The association was significant in pre and post menopausal women separately and in women diagnosed after 55 years. Women in the highest HOMA-IR quartile had higher BC risk than the lowest quartile (RR 1.44; 95% CI: 1.03-2.02). Significantly increased BC risk in women diagnosed after 55 years was also present in the highest HOMA-IR quartile; in the same group decreased BC risk was significantly associated with high SHBG. The results of this study add to the existing epidemiological evidence that hyperglycemia and insulin resistance increase BC risk.
authors.affiliation: Nutritional Epidemiology Unit, Fondazione IRCCS Istituto Nazionale dei Tumori, Milan, Italy. sabina.sieri@istitutotumori.mi.it
authors.forename: Sabina
authors.initials: S
authors.lastname: Sieri
authors.forename: Paola
authors.initials: P
authors.lastname: Muti
authors.forename: Agnoli
authors.initials: A
authors.lastname: Claudia
authors.forename: Franco
authors.initials: F
authors.lastname: Berrino
authors.forename: Valeria
authors.initials: V
authors.lastname: Pala
authors.forename: Sara
authors.initials: S
authors.lastname: Grioni
authors.forename: Carlo Alberto
authors.initials: CA
authors.lastname: Abagnato
authors.forename: Giovanni
authors.initials: G
authors.lastname: Blandino
authors.forename: Paolo
authors.initials: P
authors.lastname: Contiero
authors.forename: Holger J
authors.initials: HJ
authors.lastname: Schunemann
authors.forename: Vittorio
authors.initials: V
authors.lastname: Krogh
mesh_terms: D000328:Adult; D000368:Aged; D015992:Body Mass Index; D001943:Breast Neoplasms / Q000209:etiology* / Q000378:metabolism; D016022:Case-Control Studies; D005260:Female; D005947:Glucose / Q000378:metabolism*; D006801:Humans; D007333:Insulin Resistance; D008875:Middle Aged; D011446:Prospective Studies; D012738:Sex Hormone-Binding Globulin / Q000032:analysis
chemical_list: D012738:Sex Hormone-Binding Globulin; D005947:Glucose