Prevalence and Prognostic Significance of Renal Artery Calcification in Patients with Diabetes and Proteinuria

Background and objectives: Vascular calcification is common and severe in chronic kidney disease. Because the consequences of calcification may differ by vascular beds, we sought to test the hypothesis that patients who have diabetes with proteinuria and have significant renal artery calcification (RAC) have a higher risk for progression to ESRD. Design, setting, participants, & measurements: Using electron-beam computed tomography, RAC was computed as the sum of Agatston scores at each of the two renal ostia and renal arteries. Time-to-event analysis was conducted to compare the risk in individuals with or without significant RAC (total score >10). Results: Of 172 patients with type 2 diabetes and overt proteinuria studied (estimated GFR 56 +/- 25 ml/min per 1.73 m(2)), significant RAC was present in 31%. In 33 +/- 21 months, 41 progressed to ESRD and 65 reached a composite outcome (ESRD or death). Serum phosphorus was a significant predictor of progression to ESRD but was replaced by the significant RAC in multivariate models that included the latter. Individuals with significant RAC had a higher risk for reaching the composite outcome. In contrast, there was no association between coronary artery calcification scores and progression to ESRD. Conclusions: Significant RAC was an independent predictor of progression to ESRD as well as reaching the composite outcome. Understanding the pathogenesis of RAC would allow determination of whether this risk is potentially modifiable. Clin J Am Soc Nephrol 5: 2093-2100, 2010. doi: 10.2215/CJN.03730410