Increasing Risk of Diabetes Mellitus in Postmenopausal Women with Newly Diagnosed Primary Breast Cancer

INTRODUCTION:

We sought to determine if postmenopausal women who develop breast cancer are at increased risk of developing diabetes mellitus (DM).

MATERIALS AND METHODS:

The Taiwan National Health Insurance Research Database (NHIRD) was searched from 2001 to 2015 for women aged 55 years and older (postmenopausal) with a diagnosis of primary breast cancer. Subjects were age-matched with those without breast cancer in a 1:5 ratio. Cox proportional hazards analyses were used to examine associations between breast cancer, riskfactors and development of DM.

RESULTS:

A total of 4,607 women with primary breast cancer and 23,035 age-matched controls without breast cancer were included (mean age 58.6 ± 9.1 years). Adjusting for age, income, urbanization, Charlson comorbidity index, and medical conditions, risk of DM in subjects with breast cancer at 1, 5, 10, and 15 years was 1.70-, 1.34-, 1.27-, and 1.24-fold higher, respectively, than in subjects without breast cancer (adjusted hazard ratio [aHR] = 1.70, 95% confidence interval [CI]: 1.40, 2.05; aHR = 1.34, 95% CI: 1.17, 1.54; aHR = 1.27, 95% CI: 1.13, 1.44; aHR=1.24, 95% CI: 1.11, 1.40). Risk of DM at 1 year in breast cancer subjects receiving hormone therapy was 1.22-fold higher than in those not receiving hormone therapy (aHR = 1.22, 95% CI: 0.86, 1.74), but without statistical significance.

CONCLUSIONS:

Postmenopausal women with breast cancer are at increased risk of developing DM, independent of receiving of hormone therapy, and should be closely monitored to establish an early diagnosis and therapeutic intervention for improving related outcomes.