# Clinical Features and Implications of Albuminuria Trajectories in Type 2 Diabetes: The Fremantle Diabetes Study Phase 2

## TL;DR

This study identifies different patterns of kidney function decline in type 2 diabetes patients using urine protein measurements, showing how these patterns relate to health outcomes.

## Contribution

The study introduces a new method to classify kidney disease progression patterns in type 2 diabetes using trajectory modeling.

## Key findings

- Six distinct uACR trajectory groups were identified, including normoalbuminuria and persistent macroalbuminuria.
- The persistent macroalbuminuria group had the highest mortality and fastest kidney function decline.
- Groups returning to normoalbuminuria showed similar kidney function decline to the stable normoalbuminuria group.

## Abstract

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.

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

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.

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.

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.