Association between breast cancer and allostatic load by race: National Health and Nutrition Examination Survey 1999-2008.

BACKGROUND

Breast cancer and its treatment introduce numerous physiologic, psychological, social, and economic stressors to a woman with the diagnosis. Allostatic load, a composite score of biomarkers representing physiologic dysregulation, may serve as a measure of the biological burden of breast cancer. This study investigates the association between breast cancer and allostatic load scores by comparing allostatic load scores in those with a history of breast cancer to those without, stratified by race.

METHODS

Black and white women aged 35 to 85 were analyzed using the data from NHANES 1999-2008 (n = 4875 women, of which 188 women had a history of breast cancer). Stratified by race, we ran multivariate analyses with history of breast cancer as a predictor for elevated allostatic load while adjusting for other potentially confounding variables.

RESULTS

Although a history of breast cancer was not associated with elevated allostatic load in white women, it was significantly associated with elevated allostatic load in black women after adjusting for age, income, education, insurance type, smoking status, alcohol intake, and physical activity [Odds Ratio (OR) 2.08 (95%CI 1.02, 4.22)]. Furthermore, an interaction between black and having a history of breast cancer was found to be significant in predicting elevated allostatic load scores after adjusting for demographic, behavioral, and comorbidity characteristics.

CONCLUSIONS

These results suggest that the biological toll of breast cancer may be greater in black women than white women.