title: A longitudinal study of serum insulin and glucose levels in relation to colorectal cancer risk among postmenopausal women.
abstract: BACKGROUND
  It is unclear whether circulating insulin or glucose levels are associated with increased risk of colorectal cancer. Few prospective studies have examined this question, and only one study had repeated measurements.
  
  
  METHODS
  We conducted a prospective study of colorectal cancer risk using the subsample of women in the Women's Health Initiative study whose fasting blood samples, collected at baseline and during follow-up, were analysed for insulin and glucose. Cox proportional hazards models were used to assess associations with colorectal cancer risk in both baseline and time-dependent covariates analyses.
  
  
  RESULTS
  Among 4902 non-diabetic women with baseline fasting serum insulin and glucose values, 81 incident cases of colorectal cancer were identified over 12 years of follow-up. Baseline glucose levels were positively associated with colorectal cancer and colon cancer risk: multivariable-adjusted hazard ratio (HR) comparing the highest (≥99.5 mg dl(-1)) with the lowest tertile (<89.5 mg dl(-1)): 1.74, 95% confidence interval (CI) 0.97-3.15 and 2.25, 95% CI: 1.12-4.51, respectively. Serum insulin and homeostasis model assessment were not associated with risk. Analyses of repeated measurements supported the baseline results.
  
  
  CONCLUSIONS
  These data suggest that elevated serum glucose levels may be a risk factor for colorectal cancer in postmenopausal women.
authors: Department of Epidemiology and Population Health, Albert Einstein College of Medicine, Bronx, NY 10461, USA. geoffrey.kabat@einstein.yu.edu
authors: G C
authors: GC
authors: Kabat
authors: M Y
authors: MY
authors: Kim
authors: H D
authors: HD
authors: Strickler
authors: J M
authors: JM
authors: Shikany
authors: D
authors: D
authors: Lane
authors: J
authors: J
authors: Luo
authors: Y
authors: Y
authors: Ning
authors: M J
authors: MJ
authors: Gunter
authors: T E
authors: TE
authors: Rohan
mesh_terms: D000368:Aged; D001786:Blood Glucose / Q000032:analysis*; D015179:Colorectal Neoplasms / Q000097:blood*; D005260:Female; D006801:Humans; D007328:Insulin / Q000097:blood*; D008137:Longitudinal Studies; D008875:Middle Aged; D017698:Postmenopause; D016016:Proportional Hazards Models; D011446:Prospective Studies
chemical_list: D001786:Blood Glucose; D007328:Insulin