title: Blood glucose concentrations and breast cancer risk in women without diabetes: a meta-analysis.
abstract: OBJECTIVE
  Some studies have suggested an increased risk of breast cancer associated with elevated fasting serum glucose in nondiabetic subjects. Given how common both breast cancer and impaired glucose tolerance are in our aging societies, this is an important issue for public health.
  
  
  METHODS
  We performed a systematic review of prospective cohort studies that examined the association between elevated serum glucose levels in nondiabetic subjects (levels below 7.0 mml/L) and the subsequent risk of breast cancer. We performed a systematic literature search and extracted relevant data in a standard way. We then computed summary relative risks (SRR) and 95 % confidence intervals using a random effects model applied on the risk of highest versus lowest quantile of serum glucose concentrations.
  
  
  RESULTS
  Ten cohort studies were retrieved. The SRR for all studies was 1.11 (1.00-1.23), with no evidence of heterogeneity or publication bias. The SRR was not affected when the analysis was restricted to the 8 studies that reported results for fasting subjects (SRR = 1.11; 95 % CI 0.98-1.25). Three studies provided BMI-unadjusted and BMI-adjusted SRRs of 1.24 (95 % CI 0.60-2.56) and 1.20 (95 % CI 0.63-2.27), respectively. Similar magnitudes of associations were observed in sensitivity analyses, but statistical significance was lost.
  
  
  CONCLUSIONS
  In nondiabetic subjects, the risk of breast cancer associated with fasting serum glucose levels seems to be small. Potential limitations to this meta-analysis include the fact that not all studies reported risks adjusted for adiposity and that serum glucose levels of comparison groups were variable across studies.
authors.affiliation: International Prevention Research Institute, 95 cours Lafayette, 69006 Lyon, France.
authors.forename: Peter
authors.initials: P
authors.lastname: Boyle
authors.forename: Alice
authors.initials: A
authors.lastname: Koechlin
authors.forename: Cécile
authors.initials: C
authors.lastname: Pizot
authors.forename: Mathieu
authors.initials: M
authors.lastname: Boniol
authors.forename: Chris
authors.initials: C
authors.lastname: Robertson
authors.forename: Patrick
authors.initials: P
authors.lastname: Mullie
authors.forename: Geremia
authors.initials: G
authors.lastname: Bolli
authors.forename: Julio
authors.initials: J
authors.lastname: Rosenstock
authors.forename: Philippe
authors.initials: P
authors.lastname: Autier
mesh_terms: D001786:Blood Glucose / Q000378:metabolism*; D001943:Breast Neoplasms / Q000097:blood* / Q000453:epidemiology; D003924:Diabetes Mellitus, Type 2 / Q000097:blood* / Q000453:epidemiology; D005260:Female; D006801:Humans; D018570:Risk Assessment; D012307:Risk Factors
chemical_list: D001786:Blood Glucose