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

Abstract

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.

Keywords: Albuminuria; All-cause mortality; Cardiovascular risk score; Chronic kidney disease; Glomerular filtration rate; Type 1 diabetes mellitus.