Relation between insulin resistance and breast cancer among Chilean women.
OBJECTIVE
In Chile, diabetes and breast cancer are important public health problems. The association between insulin resistance and breast cancer, however, remains largely unexplored.


METHODS
We conducted a case-control study to assess the relationship of insulin resistance (IR) and breast cancer in Chilean premenopausal and postmenopausal women. We compared 170 women, 33 to 86 years old, with incident breast cancer and 170 normal mammography controls, matched by 5-year age interval. Plasmatic insulin and glucose were measured and IR was calculated by the homeostasis model assessment method. Anthropometric measurements and sociodemographic and behavioral data were also collected. Odds ratios (ORs) and 95% confidence intervals (CIs) were estimated by multivariable conditional logistic regression.


RESULTS
IR was independently associated with breast cancer in postmenopausal women (OR = 2.70, 95%CI = 1.10-6.63), but not in premenopausal women (OR = 0.84, 95%CI = 0.20-3.52). Obesity was not associated with breast cancer at any age (OR = 0.68, 95%CI = 0.39-1.20).


CONCLUSIONS
In this sample, IR increased the risk of breast cancer among postmenopausal women.
Garmendia
Maria Luisa
ML
School of Public Health, Faculty of Medicine, Department of Epidemiology, University of Chile, Santiago, Chile. mgarmend@med.uchile.cl
Pereira
Ana
A
Alvarado
Maria Elena
ME
Atalah
Eduardo
E
D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D001786:Blood Glucose; D001837:Body Weights and Measures; D001943:Breast Neoplasms / Q000453:epidemiology*; D016022:Case-Control Studies; D002677:Chile / Q000453:epidemiology; D005260:Female; D015438:Health Behavior; D006801:Humans; D007328:Insulin / Q000097:blood; D007333:Insulin Resistance; D008875:Middle Aged; D017584:Reproductive History; D012959:Socioeconomic Factors
D001786:Blood Glucose; D007328:Insulin