CONTEXT

The urinary albumin:creatinine ratio (uACR) can exhibit significant temporal changes but few studies have characterized transition patterns between uACR categories in type 2 diabetes.

OBJECTIVE

The study aim was to use group-based trajectory modeling (GBTM) to identify clusters of people with type 2 diabetes and distinct uACR trajectories.

METHODS

Of 1482 participants in the observational Fremantle Diabetes Study Phase 2, a total of 1145 (77.3%; mean age 65.4 years, 53.3% males) with 2 or more biennial uACR measurements over 6 years were included in GBTM. Independent baseline associates of uACR trajectory group membership were assessed using multinomial regression. Associations between group membership and changes in estimated glomerular filtration rate over 4 years were explored.

RESULTS

The optimum GBTM model comprised 6 categories: normoalbuminuria (n = 429, 37.5%), regression (n = 82, 7.2%), progression (n = 71, 6.2%), progression/regression (n = 104, 9.1%), persistent microalbuminuria (n = 401, 35.0%), and persistent macroalbuminuria (n = 58, 5.1%). The latter 5 groups had worse glycemic control than the normoalbuminuria group. The 3 groups starting from/returning to normoalbuminuria had heterogeneous baseline characteristics but a decline in renal function that was similar to the normoalbuminuric group. The persistent microalbuminuria group had adverse baseline cardiometabolic features and longitudinal renal outcomes relative to the normoalbuminuria/other microalbuminuria groups. The persistent macroalbuminuria group had, consistent with its baseline characteristics, the highest mortality (31.0% vs ≤18.5% in the other groups) and most rapid progression of renal dysfunction.

CONCLUSION

GBTM identified distinct uACR trajectory groups with clinical and prognostic implications, and could be used to stratify participants in clinical trials of new therapies for diabetic kidney disease.