Diabetes with Preserved Renal Function Is an Independent Risk Factor for Renal Function Deterioration after Coronary Computed Tomography Angiography

OBJECTIVES: Diabetes mellitus (DM) and high fasting glucose levels are reportedly risk factors for contrast-induced nephropathy after invasive coronary angiography in patients with renal dysfunction. Cystatin C (CyC) is a sensitive marker for detecting early impairment of renal function. Using CyC, we investigated whether DM would be a risk for worsening renal function after coronary computed tomography angiography (CCTA) in patients with preserved renal function. METHODS: Two hundred twenty-eight patients scheduled for CCTA were enrolled. The serum CyC at preprocedure and 1 day after procedure, urinary microalbumin at preprocedure, and oral fluid volume for 24 hours after procedure were measured. The percentage changes in CyC from preprocedure to 1 day after procedure (%CyC) were also calculated. RESULTS: Ninety-eight patients had DM. The %CyC and urinary microalbumin were significantly greater in DM patients than in non-DM patients. The percentage of patients showing a %CyC of 10% or greater was significantly greater in DM patients than in non-DM patients (27% vs 8%, P < 0.01). Using multivariate regression analysis, oral fluid volume and urinary microalbumin were independent predictors for a %CyC of 10% or greater in DM patients (β =-0.428 [P < 0.0001] and β = 0.464 [P < 0.0001], respectively). CONCLUSIONS: Diabetes mellitus is a risk factor for worsening changes in renal function after CCTA, even in patients with preserved renal function. In particular, elevated microalbuminuria and low oral fluid intake are high-risk factors for renal functional deterioration.