Type 1 Diabetes Accelerates Progression of Coronary Artery Calcium Over the Menopausal Transition: The CACTI Study

OBJECTIVE: Type 1 diabetes is associated with a higher risk of cardiovascular disease (CVD) in women. Although menopause increases risk of CVD, it is uncertain how menopause affects risk of CVD in women with type 1 diabetes. We examined whether risk of CVD changes differentially in women with and those without type 1 diabetes over the transition through menopause. RESEARCH DESIGN AND METHODS: Premenopausal women with type 1 diabetes (n = 311) and premenopausal women without diabetes (n = 325) enrolled in the Coronary Artery Calcification in Type 1 Diabetes (CACTI) study and attended up to four study visits over 18 years. Coronary artery calcium (CAC) volume was measured from computed tomography scans obtained at each visit. Longitudinal repeated-measures modeling estimated the effect of diabetes on CAC volume over time and the effect of menopause on the diabetes-CAC relationship. RESULTS: CAC volume was higher at baseline and increased more over time in women with type 1 diabetes than in women without diabetes. A significant diabetes-by-menopause interaction was found (P < 0.0001): postmenopausal women with type 1 diabetes had significantly higher CAC volumes than premenopausal women (5.14 ± 0.30 vs. 2.91 ± 0.18 mm(3)), while there was no difference in women without diabetes (1.78 ± 0.26 vs. 1.78 ± 0.17 mm(3)). This interaction remained significant after adjusting for CVD risk factors. CONCLUSIONS: Type 1 diabetes was associated with higher CAC volume and accelerated progression of CAC over time. Menopause increased CAC progression more in women with diabetes than in women without diabetes independent of age and other CVD risk factors known to worsen with menopause.