Diabetes risk higher in postmenopausal women with breast cancer
The risk of diabetes mellitus (DM) is higher among postmenopausal women who develop primary breast cancer, reports a new study.
Accessing the Taiwan National Health Insurance Research Database, researchers identified 4,607 postmenopausal women (mean age, 58.6±9.1 years) with primary breast cancer and 23,035 matched noncancer controls (mean age, 58.6±9.1 years). Cox proportional hazards analysis was performed to assess the relationship between breast cancer and DM risk.
The incidence rates of DM at 1, 5, 10 and 15 years after cancer diagnosis were 92.6, 49.5, 41.9 and 39.9 events per 1,000 person-years, respectively. In the same time span since the index date, the corresponding rates in controls were lower, at 53.6, 27.2, 24.5 and 24.0 events per 1,000 person-years.
Models adjusted for age, income, urbanization, comorbidities and other medical conditions further showed that the risk of DM 1 year after index date was significantly higher in those with breast cancer (adjusted hazard ratio [HR], 1.70, 95 percent CI, 1.40–2.05).
The same was true when DM risk was assessed at 5 (adjusted HR, 1.34, 1.17–1.54), 10 (adjusted HR, 1.27, 1.13–1.44) and 15 (adjusted HR, 1.24, 1.11–1.40) years.
Stratifying according to hormone therapy showed that at 1 year, women who were receiving hormone therapy were more likely to develop DM than those who were not, though significance was not achieved (adjusted HR, 1.22, 0.86–1.74). This indicated that the effect of breast cancer on DM risk was independent of hormone therapy, said researchers.