Background: Rapid progression of coronary artery calcification (CAC) has been reported among individuals with end-stage renal disease (ESRD). There is limited information on the progression of CAC during earlier stages of diabetic chronic kidney disease (CKD).
Methods: In a prospective, cohort study of type 2 diabetic individuals (N = 90; normoalbuminuric diabetic controls, 30; diabetic nephropathy, DN, 60), electron-beam computed tomography (EBCT) was repeated at an average interval of 19 months. All scan images were acquired at end-systole to minimize interscan variability. In order to eliminate the dependence of the residual error from interscan variability on baseline CAC scores, square root transformed CAC scores were used for analyses of progression of coronary calcification.
Results: Repeat EBCT scans were completed in 68 subjects (diabetic controls: 23; DN: 45). There was a highly significant relationship between the proportion of subjects with progressive CAC and renal disease-DN who progressed to ESRD, 80%; DN who did not progress to ESRD, 30%; and diabetic controls, 13% (P < 0.001). Similarly, the magnitude of change was significantly related to renal disease (DN who progressed to ESRD > DN who did not progress to ESRD > diabetic controls, P < 0.001). Using logistic regression and controlling for non-dialyzed DN, ESRD and inter-scan interval, advanced age was the only significant variable associated with progression of CAC. Finally, serum creatinine and baseline CAC score emerged as independent predictors for the magnitude of increase in CAC.
Conclusion: Progression of CAC is apparent among individuals with DN both before and after ESRD. However, the risk factors associated with progression of CAC may differ at different stages of CKD.