Albuminuric and non-albuminuric chronic kidney disease in type 1 diabetes: Association with major vascular outcomes risk and all-cause mortality

Aims: Albuminuric and non-albuminuric phenotypes of chronic kidney disease (CKD) may have different cardiovascular risk and survival in type 1 diabetes (T1DM). Herein we estimated risk of major vascular outcomes by the EURODIAB PCS score and determined all-cause mortality rate in 774 T1DM according to CKD phenotypes. Methods: We evaluated the distribution of CKD phenotypes [no CKD, stages 1–2, non-albuminuric stage ≥3 (Alb−CKD), albuminuric stage ≥3 (Alb+CKD)], the EURODIAB risk score for major vascular outcomes [low- (LS), intermediate- (IS), and high- (HS) risk] and all-cause mortality over a follow-up of 8.25 ± 2.34 years. Results: Out of 774 subjects, 692 (89.4%) had no CKD, 53 (6.8%) CKD stages 1–2, 17 (2.2%) Alb−CKD and 12 (1.6%) Alb+CKD; 466 (60.2%) had LS, 205 (26.5%) IS and 103 (13.3%) HS. Distribution of HS was: no CKD, 9.1%; CKD stages 1–2, 34.0%; Alb−CKD, 64.7%; Alb+CKD, 91.7% (P < 0.0001). Mortality increased from no CKD, 3.0%; to stages 1–2, 15.1% (HR 4.504); Alb−CKD, 29.4% (8.573); Alb+CKD, 50.0% (20.683, P < 0.0001). Accounting for age and sex, HRs for mortality compared to no CKD were: CKD stages 1–2, 3.84 (P = 0.001); Alb−CKD, 2.97 (P = 0.046); Alb+CKD, 7.44 (P < 0.0001). Adjusting for sex and the EURODIAB score, HRs for mortality compared to no CKD were: CKD stages 1–2, 2.57 (P = 0.027); Alb−CKD, 2.77 (P = 0.058); Alb+CKD, 4.58 (P = 0.003). Conclusions: In our T1DM cohort, one fifth of those with CKDs were non-albuminuric. This phenotype was associated with higher risk of major outcomes and similar rate of mortality as compared to CKD stages 1–2. The greatest risk and highest mortality occur in patients with Alb+CKD.