515-P: Nonalbuminuric Diabetic Kidney Disease in Type 1 Diabetes: Incidence of Major Vascular Outcomes over a 10-Year Follow-Up

Non-albuminuric diabetic kidney disease (Alb^-DKD) has been associated with a raised risk of CV outcomes and all-cause mortality in T1D. We report about the association between DKD phenotypes and CV outcomes in a single-centre, prospective, 10.4±2.9 years observation of 774 T1D. Rates of outcomes and vital status were censored on December 2017. Out of 774 T1D, 692 (89.4%) had no-DKD, 53 DKD 1-2 (6.8%), 17 (2.2%) Alb^-DKD and 12 (1.6%) Alb⁺DKD. Incidences of CV outcomes, coronary events and ESRD were available for 736 subjects (95.1%). A CV event occurred in 49 T1D (6.7%; 6.42 events x 1000 PYs), rising from no-DKD (4.2%) to DKD 1-2 (28.6%) and Alb^-DKD (35.3%). In Alb⁺DKD, due to competition with all-cause death, only 1 event occurred. Compared to no-DKD, the adjusted HRs were 4.43 (95%CI 2.27-8.61, p<0.0001) in DKD 1-2 and 3.44 (1.34-8.81, p=0.010) in Alb^-DKD. After further adjustment for prior CVD, the HR was fully preserved for DKD 1-2 (p<0.0001), but attenuated for Alb-DKD (p=0.064). A coronary event occurred in 35 T1D (4.8%; 4.54 events x1000 PYs), rising from 3.0% in no-DKD to 18.4% in DKD 1-2 and 29.4% in Alb^-DKD. Compared to no-DKD, the adjusted HRs were 3.85 (1.72-8.65, p=0.001) in DKD 1-2 and 4.75 (1.66-13.56, p=0.004) in Alb^-DKD. After adjustment for prior CVD, the HRs were preserved for both DKD 1-2 (p<0.0001) and Alb^-DKD (p=0.016). Only 11 subjects developed ESRD (1.5%): 0.9% in no-DKD, 2.0% in DKD 1-2, 17.6% in Alb^-DKD and 10.0% in Alb⁺DKD. Compared to no-DKD, the risk of ESRD raised only in Alb^-DKD (HR 6.59, 95%CI 1.31-33.20, p=0.022). After adjustment for prior CVD, this HR was 5.26 (p=0.058). Compared to no-DKD, the risk of death was increased to the same extent of about four-five fold in Alb^-DKD and Alb⁺DKD (p<0.0001). In T1D, Alb^-DKD was independently associated to a raised rate of CV, mainly coronary, morbidity. Though preliminary, our data do not to confirm Alb^-DKD does not increase risk of ESRD. This DKD phenotype deserves intensive prevention strategies.