Impaired Renal Function Further Increases Odds of 6-Year Coronary Artery Calcification Progression in Adults With Type 1 Diabetes: The CACTI study

OBJECTIVE: To determine whether baseline estimated glomerular filtration rate (eGFR) and albumin-to-creatinine ratio (ACR) independently predict coronary artery calcification (CAC) progression, and to determine how eGFR changes over 6 years in adults with type 1 diabetes compared with nondiabetic adults. RESEARCH DESIGN AND METHODS: The Coronary Artery Calcification in Type 1 Diabetes study participants (n = 1,066) with complete data for eGFR assessment at baseline and 6 years were included. Three Chronic Kidney Disease Epidemiology Collaboration equations (serum creatinine, cystatin C, and both) were used to estimate eGFR. The association of baseline ACR and eGFR with CAC progression was analyzed using multiple logistic regression. RESULTS: Increasing categorical baseline ACR (<10, 10–30, and >30 µg/mg) predicted CAC progression in participants with type 1 diabetes (odds ratio [OR], 2.15; 95% CI, 1.50–3.09; 7.19 [3.90–13.26]; and 18.09 [8.48–38.62]), respectively, compared with nondiabetic subjects. Baseline eGFR <60 mL/min/1.73 m(2) also predicted CAC progression (OR, 5–7, compared with nondiabetic participants). ORs for CAC progression were higher in women than in men when using the cystatin C–based Chronic Kidney Disease Epidemiology Collaboration equations. Participants with type 1 diabetes had greater eGFR decreases over 6 years than nondiabetic participants using cystatin C–based equations. CONCLUSIONS: Although increasing ACR or decreasing eGFR predicts CAC progression, coronary atherosclerosis progresses faster in people with type 1 diabetes even in the absence of diabetic kidney disease. These findings emphasize the interaction between kidney disease and cardiovascular disease in type 1 diabetes and highlight the public health importance of lowering cardiorenal risk in people with type 1 diabetes.