Components of metabolic syndrome increased risk for breast cancer in postmenopausal women

Postmenopausal women with metabolic syndrome appear to be at increased risk for breast cancer, according to results of a longitudinal study.

Researchers assessed the association of metabolic syndrome and risk for breast cancer in postmenopausal women included in the Women’s Health Initiative.

During eight years of follow-up, the researchers identified 165 incident cases of breast cancer (34 in-situ and 131 invasive) in 4,888 women without diabetes.

The presence of metabolic syndrome at baseline was not associated with altered risk of breast cancer; however, individual components measured at baseline showed a borderline positive association, particularly diastolic blood pressure (HR=1.55).

Time-dependent covariate analyses revealed a positive association between metabolic syndrome and breast cancer “due primarily to positive associations with serum glucose (P=.04), serum triglycerides (P=.03) and diastolic blood pressure (P=.001),” the researchers wrote.

Identification of metabolic syndrome three to five years before diagnosis of breast cancer was associated with an increased risk for total (HR=1.84) and invasive breast cancer (HR=1.77).

“It would be premature to give advice to the public based on the results of this initial, relatively small study,” Geoffrey C. Kabat, PhD, of the department of epidemiology and population health at Albert Einstein College of Medicine in New York, told Endocrine Today. “There is a need for further, larger studies; however, if metabolic syndrome or insulin resistance does turn out to play a role in breast cancer, existing recommendations to maintain a healthy body weight and to engage in physical activity would be beneficial in this regard.” – by Jennifer Southall

Kabat GC. Cancer Epidemiol Biomarkers Prev. 2009;18: 2046–2053.