Adiponectin and IGF-1 in Women with Obesity and/or Breast Cancer

Objective: to see if proteins associated with obesity are present in saliva and if they are present and altered in a diseased state, such as in a patient with breast cancer.

Our null hypothesis is that there are no significant annalyte differences between the obese state, the non-obese state, the diseased state, and the non-diseased state.

Methods: We tested for two specific protein markers in saliva. The presence and concentration of insulin-like growth factor (IGF-I) and adiponectin were determined using the ELISA assay method. Saliva samples were divided into four groups of test subjects, each consisting of 15 Caucasian women and age matched. The four groups include subjects who are healthy and of normal BMI; are healthy but have an elevated BMI; have cancer and a normal BMI; and have cancer and an elevated BMI.

Results: We found a significant increase in mean adiponectin levels in subjects with cancer compared to the controls. IGF-I was found to be elevated in the obese cancer group. Adiponectin was also found to be correlated to IGF-I levels, BMI, and age.

Conclusion: Salivary adiponectin levels for controls follow reported patterns for plasma adiponectin, but are unexpectedly high in both cancer groups. The mechanism for this is not clearly understood, but may be related to the leptin/estrogen receptor pathway of proliferation in mammary epithelial cells. The increase in IGF-I in the obese cancer group is consistent with previous findings for breast cancer subjects.