Granular Cast in Urine Sediment as an Overlooked and Independent Risk Factor for Diabetic Kidney Disease in Type 2...

Urine cast analysis is a rapid, cost-effective test that may reflect changes in renal function. In the current study, we evaluated urine cast as a risk factor of the occurrence and severity of diabetic kidney disease (DKD) in patients with type 2 diabetes mellitus (T2DM).

Hospitalised T2DM patients were classified into DKD (n = 299) and Non-DKD (n = 301) groups. Data on urinalysis (including casts), demographics, and biochemical parameters were compared, followed by correlation analysis using logistic regression. Receiver operating characteristic (ROC) curve was constructed to assess the diagnostic potential of urine casts for DKD.

In comparison to Non-DKD patients, DKD patients showed significantly higher detection rates of granular casts (19.7% vs. 1.0%). Additionally, the DKD patients had significantly higher average counts of granular casts (0.55 ± 1.68 vs. 0.01 ± 0.10). Granular cast was an independent risk factor for coincident occurrence of DKD in T2DM patients (OR = 4.696, 95% CI: 1.094-20.168) after multivariate adjustment. ROC analysis showed 19.7% sensitivity and 99.0% specificity (accuracy) at a cutoff of 0.5 using granular cast to diagnose DKD. Furthermore, Non-DKD patients with the presence of granular casts had a higher incidence of developing new-onset DKD than those without in 1 year follow-up (66.7% vs. 12.05%).

Granular cast is an independent risk factor for the occurrence and is positively associated with disease severity of DKD in patients with T2DM. The presence of granular casts also indicates an increased risk of the future development of DKD in T2DM patients.