FRIDAY, Sept. 19, 2025 (HealthDay News) -- Hormone replacement therapy (HRT) patches carry lower cardiovascular risk than oral HRT among women with type 2 diabetes, according to a study presented at the annual meeting of the European Association for the Study of Diabetes, held from Sept. 15 to 19 in Vienna.Matthew Anson, from University of Liverpool in the United Kingdom, and colleagues used TriNetX electronic health record data to understand cardiovascular risk and gynecological- and estrogen-related cancers among women with type 2 diabetes using and not using HRT in midlife. The analysis included data from three cohorts composed of 24,986 patients.The researchers found that in cohort 1, compared with HRT users without diabetes, transdermal HRT in women with diabetes was associated with a greater risk for deep vein thrombosis (hazard ratio [HR], 1.90; P = 0.002), ischemic heart disease (HR, 1.77; P < 0.001), and cerebral infarction (HR, 1.89; P < 0.001). There were no differences in rates of pulmonary embolism and breast, ovarian, or endometrial carcinoma. In cohort 2, among individuals with diabetes, use of transdermal HRT was associated with only a reduced risk for ischemic heart disease (HR, 0.75; P < 0.001) compared with nonusers. In cohort , among individuals with diabetes, use of oral versus transdermal HRT was associated with an increased risk for ischemic heart disease (HR, 1.21; P = 0.004) and pulmonary embolism (HR, 2.01; P < 0.001), but with no differences in risk for the other outcomes.“Our study suggests that up to five years of regulator-approved doses of transdermal HRT appears safe in a large cohort of women in midlife with type 2 diabetes,” Anson said in a statement. “However, given increased risks with oral HRT, we propose that women with type 2 diabetes should not be prescribed oral estrogen therapy.”AbstractMore Information.Sign up for our weekly HealthDay newsletter