Adverse Outcomes Across KDIGO Categories for Patients With T1DM

Kianoush Makvandi and others observed that the Kidney Disease Improving Global Outcomes (KDIGO) classifications for evaluating the burden and impact of renal and cardiovascular (CV) adverse outcomes in patients with type 1 diabetes mellitus (T1DM) were underutilized. Therefore, they conducted a study to better understand: (1) the distribution of various KDIGO categories across the cohort, (2) the incidence of adverse renal and CV events for each category, and (3) the association of baseline KDIGO category and future excess risk for five major outcomes. Their results were presented at the 61st European Renal Association Congress.

A total of 39,067 patients from the Swedish National Diabetes Register were included in the study, all of whom had T1DM. Based on their baseline albuminuria and creatinine, they were categorized into G1 to G5 estimated glomerular filtration rate (eGFR) and A1 to A3 albuminuria groups.

Outcomes of interest for the study included acute kidney injury, 40% eGFR decline from baseline, kidney failure (KF), renal death, and a composite outcome of either of the preceding renal outcomes (MAKE). CV outcomes were also tracked and included coronary heart disease, stroke and CV death, and a composite outcome comprising either of the preceding CV outcomes and heart failure (MACE). The researchers also analyzed all-cause mortality.

The researchers used Kaplan-Meier survival curves to assess cumulative incidence of outcomes, calculating the incidence rate per 1000 person-years. They used Cox proportional hazards regression risk models to study the association between baseline KDIGO category and the risk of five major outcomes: 40% eGFR decline, KF, MAKE, MACE, and all-cause mortality.

The mean follow-up was 9.1 years (350,000 person-years). Chronic kidney disease (eGFR <60 ml/min/1.73 m² and/or albuminuria) was present in 18.5% of participants; 8.1% were normoalbuminuric. In both the increasing eGFR and albuminuria categories, there was a progressive increase in the incidence and adjusted hazard ratio for all outcomes. This was true even in subjects with eGFR ≥60 ml/min/1.73 m².

Cox regression analyses were conducted referencing KDIGO categories combining G1A1 and G2A1 and then using only G1A1. Unexpectedly, repeat analysis using G1A1 alone found significantly elevated risk for all five major outcomes, even in G2A1, although this category normally would be considered low risk.

In sum, the study authors wrote, “A progressively increasing burden of adverse cardiorenal outcomes, including mortality, was observed with advancing KDIGO categories in [the] T1DM population. Even in subjects with preserved eGFR and normoalbuminuria, we identified an elevated risk for all major outcomes, indicating that early screening and implementation of preventive strategies may be beneficial in improving prognosis of this population.”

Source: Makvandi K, Eliasson B, Carlsen HK, Baid-Agrawal S. Burden and excess risk of adverse outcomes in patients with type 1 diabetes utilizing KDIGO classification: a national cohort study. Abstract #1750. Presented at the 61st European Renal Association Congress; May 23-26, 2024; Stockholm, Sweden.